/* * ECMAScript compiler. * * Parses an input string and generates a function template result. * Compilation may happen in multiple contexts (global code, eval * code, function code). * * The parser uses a traditional top-down recursive parsing for the * statement level, and an operator precedence based top-down approach * for the expression level. The attempt is to minimize the C stack * depth. Bytecode is generated directly without an intermediate * representation (tree), at the cost of needing two (and sometimes * three) passes over each function. * * The top-down recursive parser functions are named "duk__parse_XXX". * * Recursion limits are in key functions to prevent arbitrary C recursion: * function body parsing, statement parsing, and expression parsing. * * See doc/compiler.rst for discussion on the design. * * A few typing notes: * * - duk_regconst_t: signed, highest bit set (< 0) means constant, * some call sites use -1 for "none" (equivalent to constant 0x7fffffff) * - PC values: duk_int_t, negative values used as markers */ #include "duk_internal.h" /* If highest bit of a register number is set, it refers to a constant instead. * When interpreted as a signed value, this means const values are always * negative (when interpreted as two's complement). For example DUK__ISREG_TEMP() * uses this approach to avoid an explicit DUK__ISREG() check (the condition is * logically "'x' is a register AND 'x' >= temp_first"). */ #define DUK__CONST_MARKER DUK_REGCONST_CONST_MARKER #define DUK__REMOVECONST(x) ((x) & ~DUK__CONST_MARKER) #define DUK__ISREG(x) ((x) >= 0) #define DUK__ISCONST(x) ((x) < 0) #define DUK__ISREG_TEMP(comp_ctx,x) ((duk_int32_t) (x) >= (duk_int32_t) ((comp_ctx)->curr_func.temp_first)) /* Check for x >= temp_first && x >= 0 by comparing as signed. */ #define DUK__ISREG_NOTTEMP(comp_ctx,x) ((duk_uint32_t) (x) < (duk_uint32_t) ((comp_ctx)->curr_func.temp_first)) /* Check for x >= 0 && x < temp_first by interpreting as unsigned. */ #define DUK__GETTEMP(comp_ctx) ((comp_ctx)->curr_func.temp_next) #define DUK__SETTEMP(comp_ctx,x) ((comp_ctx)->curr_func.temp_next = (x)) /* dangerous: must only lower (temp_max not updated) */ #define DUK__SETTEMP_CHECKMAX(comp_ctx,x) duk__settemp_checkmax((comp_ctx),(x)) #define DUK__ALLOCTEMP(comp_ctx) duk__alloctemp((comp_ctx)) #define DUK__ALLOCTEMPS(comp_ctx,count) duk__alloctemps((comp_ctx),(count)) /* Init value set size for array and object literals. */ #define DUK__MAX_ARRAY_INIT_VALUES 20 #define DUK__MAX_OBJECT_INIT_PAIRS 10 /* XXX: hack, remove when const lookup is not O(n) */ #define DUK__GETCONST_MAX_CONSTS_CHECK 256 /* These limits are based on bytecode limits. Max temps is limited * by duk_hcompfunc nargs/nregs fields being 16 bits. */ #define DUK__MAX_CONSTS DUK_BC_BC_MAX #define DUK__MAX_FUNCS DUK_BC_BC_MAX #define DUK__MAX_TEMPS 0xffffL /* Initial bytecode size allocation. */ #if defined(DUK_USE_PREFER_SIZE) #define DUK__BC_INITIAL_INSTS 16 #else #define DUK__BC_INITIAL_INSTS 256 #endif #define DUK__RECURSION_INCREASE(comp_ctx,thr) do { \ DUK_DDD(DUK_DDDPRINT("RECURSION INCREASE: %s:%ld", (const char *) DUK_FILE_MACRO, (long) DUK_LINE_MACRO)); \ duk__comp_recursion_increase((comp_ctx)); \ } while (0) #define DUK__RECURSION_DECREASE(comp_ctx,thr) do { \ DUK_DDD(DUK_DDDPRINT("RECURSION DECREASE: %s:%ld", (const char *) DUK_FILE_MACRO, (long) DUK_LINE_MACRO)); \ duk__comp_recursion_decrease((comp_ctx)); \ } while (0) /* Value stack slot limits: these are quite approximate right now, and * because they overlap in control flow, some could be eliminated. */ #define DUK__COMPILE_ENTRY_SLOTS 8 #define DUK__FUNCTION_INIT_REQUIRE_SLOTS 16 #define DUK__FUNCTION_BODY_REQUIRE_SLOTS 16 #define DUK__PARSE_STATEMENTS_SLOTS 16 #define DUK__PARSE_EXPR_SLOTS 16 /* Temporary structure used to pass a stack allocated region through * duk_safe_call(). */ typedef struct { duk_small_uint_t flags; duk_compiler_ctx comp_ctx_alloc; duk_lexer_point lex_pt_alloc; } duk__compiler_stkstate; /* * Prototypes */ /* lexing */ DUK_LOCAL_DECL void duk__advance_helper(duk_compiler_ctx *comp_ctx, duk_small_int_t expect); DUK_LOCAL_DECL void duk__advance_expect(duk_compiler_ctx *comp_ctx, duk_small_int_t expect); DUK_LOCAL_DECL void duk__advance(duk_compiler_ctx *ctx); /* function helpers */ DUK_LOCAL_DECL void duk__init_func_valstack_slots(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL void duk__reset_func_for_pass2(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL void duk__init_varmap_and_prologue_for_pass2(duk_compiler_ctx *comp_ctx, duk_regconst_t *out_stmt_value_reg); DUK_LOCAL_DECL void duk__convert_to_func_template(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL duk_int_t duk__cleanup_varmap(duk_compiler_ctx *comp_ctx); /* code emission */ DUK_LOCAL_DECL duk_int_t duk__get_current_pc(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL duk_compiler_instr *duk__get_instr_ptr(duk_compiler_ctx *comp_ctx, duk_int_t pc); DUK_LOCAL_DECL void duk__emit(duk_compiler_ctx *comp_ctx, duk_instr_t ins); DUK_LOCAL_DECL void duk__emit_op_only(duk_compiler_ctx *comp_ctx, duk_small_uint_t op); DUK_LOCAL_DECL void duk__emit_a_b_c(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a, duk_regconst_t b, duk_regconst_t c); DUK_LOCAL_DECL void duk__emit_a_b(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a, duk_regconst_t b); DUK_LOCAL_DECL void duk__emit_b_c(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t b, duk_regconst_t c); #if 0 /* unused */ DUK_LOCAL_DECL void duk__emit_a(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a); DUK_LOCAL_DECL void duk__emit_b(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t b); #endif DUK_LOCAL_DECL void duk__emit_a_bc(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a, duk_regconst_t bc); DUK_LOCAL_DECL void duk__emit_bc(duk_compiler_ctx *comp_ctx, duk_small_uint_t op, duk_regconst_t bc); DUK_LOCAL_DECL void duk__emit_abc(duk_compiler_ctx *comp_ctx, duk_small_uint_t op, duk_regconst_t abc); DUK_LOCAL_DECL void duk__emit_load_int32(duk_compiler_ctx *comp_ctx, duk_regconst_t reg, duk_int32_t val); DUK_LOCAL_DECL void duk__emit_load_int32_noshuffle(duk_compiler_ctx *comp_ctx, duk_regconst_t reg, duk_int32_t val); DUK_LOCAL_DECL void duk__emit_jump(duk_compiler_ctx *comp_ctx, duk_int_t target_pc); DUK_LOCAL_DECL duk_int_t duk__emit_jump_empty(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL void duk__insert_jump_entry(duk_compiler_ctx *comp_ctx, duk_int_t jump_pc); DUK_LOCAL_DECL void duk__patch_jump(duk_compiler_ctx *comp_ctx, duk_int_t jump_pc, duk_int_t target_pc); DUK_LOCAL_DECL void duk__patch_jump_here(duk_compiler_ctx *comp_ctx, duk_int_t jump_pc); DUK_LOCAL_DECL void duk__patch_trycatch(duk_compiler_ctx *comp_ctx, duk_int_t ldconst_pc, duk_int_t trycatch_pc, duk_regconst_t reg_catch, duk_regconst_t const_varname, duk_small_uint_t flags); DUK_LOCAL_DECL void duk__emit_if_false_skip(duk_compiler_ctx *comp_ctx, duk_regconst_t regconst); DUK_LOCAL_DECL void duk__emit_if_true_skip(duk_compiler_ctx *comp_ctx, duk_regconst_t regconst); DUK_LOCAL_DECL void duk__emit_invalid(duk_compiler_ctx *comp_ctx); /* ivalue/ispec helpers */ DUK_LOCAL_DECL void duk__ivalue_regconst(duk_ivalue *x, duk_regconst_t regconst); DUK_LOCAL_DECL void duk__ivalue_plain_fromstack(duk_compiler_ctx *comp_ctx, duk_ivalue *x); DUK_LOCAL_DECL void duk__ivalue_var_fromstack(duk_compiler_ctx *comp_ctx, duk_ivalue *x); DUK_LOCAL_DECL void duk__ivalue_var_hstring(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_hstring *h); DUK_LOCAL_DECL void duk__copy_ispec(duk_compiler_ctx *comp_ctx, duk_ispec *src, duk_ispec *dst); DUK_LOCAL_DECL void duk__copy_ivalue(duk_compiler_ctx *comp_ctx, duk_ivalue *src, duk_ivalue *dst); DUK_LOCAL_DECL duk_regconst_t duk__alloctemps(duk_compiler_ctx *comp_ctx, duk_small_int_t num); DUK_LOCAL_DECL duk_regconst_t duk__alloctemp(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL void duk__settemp_checkmax(duk_compiler_ctx *comp_ctx, duk_regconst_t temp_next); DUK_LOCAL_DECL duk_regconst_t duk__getconst(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL duk_regconst_t duk__ispec_toregconst_raw(duk_compiler_ctx *comp_ctx, duk_ispec *x, duk_regconst_t forced_reg, duk_small_uint_t flags); DUK_LOCAL_DECL void duk__ispec_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ispec *x, duk_regconst_t forced_reg); DUK_LOCAL_DECL void duk__ivalue_toplain_raw(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_regconst_t forced_reg); DUK_LOCAL_DECL void duk__ivalue_toplain(duk_compiler_ctx *comp_ctx, duk_ivalue *x); DUK_LOCAL_DECL void duk__ivalue_toplain_ignore(duk_compiler_ctx *comp_ctx, duk_ivalue *x); DUK_LOCAL_DECL duk_regconst_t duk__ivalue_toregconst_raw(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_regconst_t forced_reg, duk_small_uint_t flags); DUK_LOCAL_DECL duk_regconst_t duk__ivalue_toreg(duk_compiler_ctx *comp_ctx, duk_ivalue *x); #if 0 /* unused */ DUK_LOCAL_DECL duk_regconst_t duk__ivalue_totemp(duk_compiler_ctx *comp_ctx, duk_ivalue *x); #endif DUK_LOCAL_DECL void duk__ivalue_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_int_t forced_reg); DUK_LOCAL_DECL duk_regconst_t duk__ivalue_toregconst(duk_compiler_ctx *comp_ctx, duk_ivalue *x); DUK_LOCAL_DECL duk_regconst_t duk__ivalue_totempconst(duk_compiler_ctx *comp_ctx, duk_ivalue *x); /* identifier handling */ DUK_LOCAL_DECL duk_regconst_t duk__lookup_active_register_binding(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL duk_bool_t duk__lookup_lhs(duk_compiler_ctx *ctx, duk_regconst_t *out_reg_varbind, duk_regconst_t *out_rc_varname); /* label handling */ DUK_LOCAL_DECL void duk__add_label(duk_compiler_ctx *comp_ctx, duk_hstring *h_label, duk_int_t pc_label, duk_int_t label_id); DUK_LOCAL_DECL void duk__update_label_flags(duk_compiler_ctx *comp_ctx, duk_int_t label_id, duk_small_uint_t flags); DUK_LOCAL_DECL void duk__lookup_active_label(duk_compiler_ctx *comp_ctx, duk_hstring *h_label, duk_bool_t is_break, duk_int_t *out_label_id, duk_int_t *out_label_catch_depth, duk_int_t *out_label_pc, duk_bool_t *out_is_closest); DUK_LOCAL_DECL void duk__reset_labels_to_length(duk_compiler_ctx *comp_ctx, duk_size_t len); /* top-down expression parser */ DUK_LOCAL_DECL void duk__expr_nud(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__expr_led(duk_compiler_ctx *comp_ctx, duk_ivalue *left, duk_ivalue *res); DUK_LOCAL_DECL duk_small_uint_t duk__expr_lbp(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL duk_bool_t duk__expr_is_empty(duk_compiler_ctx *comp_ctx); /* exprtop is the top level variant which resets nud/led counts */ DUK_LOCAL_DECL void duk__expr(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); DUK_LOCAL_DECL void duk__exprtop(duk_compiler_ctx *ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); /* convenience helpers */ #if 0 /* unused */ DUK_LOCAL_DECL duk_regconst_t duk__expr_toreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #endif #if 0 /* unused */ DUK_LOCAL_DECL duk_regconst_t duk__expr_totemp(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #endif DUK_LOCAL_DECL void duk__expr_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags, duk_regconst_t forced_reg); DUK_LOCAL_DECL duk_regconst_t duk__expr_toregconst(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #if 0 /* unused */ DUK_LOCAL_DECL duk_regconst_t duk__expr_totempconst(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #endif DUK_LOCAL_DECL void duk__expr_toplain(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); DUK_LOCAL_DECL void duk__expr_toplain_ignore(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); DUK_LOCAL_DECL duk_regconst_t duk__exprtop_toreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #if 0 /* unused */ DUK_LOCAL_DECL duk_regconst_t duk__exprtop_totemp(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #endif DUK_LOCAL_DECL void duk__exprtop_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags, duk_regconst_t forced_reg); DUK_LOCAL_DECL duk_regconst_t duk__exprtop_toregconst(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #if 0 /* unused */ DUK_LOCAL_DECL void duk__exprtop_toplain_ignore(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags); #endif /* expression parsing helpers */ DUK_LOCAL_DECL duk_int_t duk__parse_arguments(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__nud_array_literal(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__nud_object_literal(duk_compiler_ctx *comp_ctx, duk_ivalue *res); /* statement parsing */ DUK_LOCAL_DECL void duk__parse_var_decl(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t expr_flags, duk_regconst_t *out_reg_varbind, duk_regconst_t *out_rc_varname); DUK_LOCAL_DECL void duk__parse_var_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t expr_flags); DUK_LOCAL_DECL void duk__parse_for_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site); DUK_LOCAL_DECL void duk__parse_switch_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site); DUK_LOCAL_DECL void duk__parse_if_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__parse_do_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site); DUK_LOCAL_DECL void duk__parse_while_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site); DUK_LOCAL_DECL void duk__parse_break_or_continue_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__parse_return_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__parse_throw_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__parse_try_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__parse_with_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res); DUK_LOCAL_DECL void duk__parse_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_bool_t allow_source_elem); DUK_LOCAL_DECL duk_int_t duk__stmt_label_site(duk_compiler_ctx *comp_ctx, duk_int_t label_id); DUK_LOCAL_DECL void duk__parse_stmts(duk_compiler_ctx *comp_ctx, duk_bool_t allow_source_elem, duk_bool_t expect_eof, duk_bool_t regexp_after); DUK_LOCAL_DECL void duk__parse_func_body(duk_compiler_ctx *comp_ctx, duk_bool_t expect_eof, duk_bool_t implicit_return_value, duk_bool_t regexp_after, duk_small_int_t expect_token); DUK_LOCAL_DECL void duk__parse_func_formals(duk_compiler_ctx *comp_ctx); DUK_LOCAL_DECL void duk__parse_func_like_raw(duk_compiler_ctx *comp_ctx, duk_small_uint_t flags); DUK_LOCAL_DECL duk_int_t duk__parse_func_like_fnum(duk_compiler_ctx *comp_ctx, duk_small_uint_t flags); #define DUK__FUNC_FLAG_DECL (1 << 0) /* Parsing a function declaration. */ #define DUK__FUNC_FLAG_GETSET (1 << 1) /* Parsing an object literal getter/setter. */ #define DUK__FUNC_FLAG_METDEF (1 << 2) /* Parsing an object literal method definition shorthand. */ #define DUK__FUNC_FLAG_PUSHNAME_PASS1 (1 << 3) /* Push function name when creating template (first pass only). */ #define DUK__FUNC_FLAG_USE_PREVTOKEN (1 << 4) /* Use prev_token to start function parsing (workaround for object literal). */ /* * Parser control values for tokens. The token table is ordered by the * DUK_TOK_XXX defines. * * The binding powers are for lbp() use (i.e. for use in led() context). * Binding powers are positive for typing convenience, and bits at the * top should be reserved for flags. Binding power step must be higher * than 1 so that binding power "lbp - 1" can be used for right associative * operators. Currently a step of 2 is used (which frees one more bit for * flags). */ /* XXX: actually single step levels would work just fine, clean up */ /* binding power "levels" (see doc/compiler.rst) */ #define DUK__BP_INVALID 0 /* always terminates led() */ #define DUK__BP_EOF 2 #define DUK__BP_CLOSING 4 /* token closes expression, e.g. ')', ']' */ #define DUK__BP_FOR_EXPR DUK__BP_CLOSING /* bp to use when parsing a top level Expression */ #define DUK__BP_COMMA 6 #define DUK__BP_ASSIGNMENT 8 #define DUK__BP_CONDITIONAL 10 #define DUK__BP_LOR 12 #define DUK__BP_LAND 14 #define DUK__BP_BOR 16 #define DUK__BP_BXOR 18 #define DUK__BP_BAND 20 #define DUK__BP_EQUALITY 22 #define DUK__BP_RELATIONAL 24 #define DUK__BP_SHIFT 26 #define DUK__BP_ADDITIVE 28 #define DUK__BP_MULTIPLICATIVE 30 #define DUK__BP_EXPONENTIATION 32 #define DUK__BP_POSTFIX 34 #define DUK__BP_CALL 36 #define DUK__BP_MEMBER 38 #define DUK__TOKEN_LBP_BP_MASK 0x1f #define DUK__TOKEN_LBP_FLAG_NO_REGEXP (1 << 5) /* regexp literal must not follow this token */ #define DUK__TOKEN_LBP_FLAG_TERMINATES (1 << 6) /* terminates expression; e.g. post-increment/-decrement */ #define DUK__TOKEN_LBP_FLAG_UNUSED (1 << 7) /* unused */ #define DUK__TOKEN_LBP_GET_BP(x) ((duk_small_uint_t) (((x) & DUK__TOKEN_LBP_BP_MASK) * 2)) #define DUK__MK_LBP(bp) ((bp) >> 1) /* bp is assumed to be even */ #define DUK__MK_LBP_FLAGS(bp,flags) (((bp) >> 1) | (flags)) DUK_LOCAL const duk_uint8_t duk__token_lbp[] = { DUK__MK_LBP(DUK__BP_EOF), /* DUK_TOK_EOF */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_IDENTIFIER */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_BREAK */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_CASE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_CATCH */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_CONTINUE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_DEBUGGER */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_DEFAULT */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_DELETE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_DO */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_ELSE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_FINALLY */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_FOR */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_FUNCTION */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_IF */ DUK__MK_LBP(DUK__BP_RELATIONAL), /* DUK_TOK_IN */ DUK__MK_LBP(DUK__BP_RELATIONAL), /* DUK_TOK_INSTANCEOF */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_NEW */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_RETURN */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_SWITCH */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_THIS */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_THROW */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_TRY */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_TYPEOF */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_VAR */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_CONST */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_VOID */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_WHILE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_WITH */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_CLASS */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_ENUM */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_EXPORT */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_EXTENDS */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_IMPORT */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_SUPER */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_NULL */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_TRUE */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_FALSE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_GET */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_SET */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_IMPLEMENTS */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_INTERFACE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_LET */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_PACKAGE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_PRIVATE */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_PROTECTED */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_PUBLIC */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_STATIC */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_YIELD */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_LCURLY */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_RCURLY */ DUK__MK_LBP(DUK__BP_MEMBER), /* DUK_TOK_LBRACKET */ DUK__MK_LBP_FLAGS(DUK__BP_CLOSING, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_RBRACKET */ DUK__MK_LBP(DUK__BP_CALL), /* DUK_TOK_LPAREN */ DUK__MK_LBP_FLAGS(DUK__BP_CLOSING, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_RPAREN */ DUK__MK_LBP(DUK__BP_MEMBER), /* DUK_TOK_PERIOD */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_SEMICOLON */ DUK__MK_LBP(DUK__BP_COMMA), /* DUK_TOK_COMMA */ DUK__MK_LBP(DUK__BP_RELATIONAL), /* DUK_TOK_LT */ DUK__MK_LBP(DUK__BP_RELATIONAL), /* DUK_TOK_GT */ DUK__MK_LBP(DUK__BP_RELATIONAL), /* DUK_TOK_LE */ DUK__MK_LBP(DUK__BP_RELATIONAL), /* DUK_TOK_GE */ DUK__MK_LBP(DUK__BP_EQUALITY), /* DUK_TOK_EQ */ DUK__MK_LBP(DUK__BP_EQUALITY), /* DUK_TOK_NEQ */ DUK__MK_LBP(DUK__BP_EQUALITY), /* DUK_TOK_SEQ */ DUK__MK_LBP(DUK__BP_EQUALITY), /* DUK_TOK_SNEQ */ DUK__MK_LBP(DUK__BP_ADDITIVE), /* DUK_TOK_ADD */ DUK__MK_LBP(DUK__BP_ADDITIVE), /* DUK_TOK_SUB */ DUK__MK_LBP(DUK__BP_MULTIPLICATIVE), /* DUK_TOK_MUL */ DUK__MK_LBP(DUK__BP_MULTIPLICATIVE), /* DUK_TOK_DIV */ DUK__MK_LBP(DUK__BP_MULTIPLICATIVE), /* DUK_TOK_MOD */ DUK__MK_LBP(DUK__BP_EXPONENTIATION), /* DUK_TOK_EXP */ DUK__MK_LBP_FLAGS(DUK__BP_POSTFIX, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_INCREMENT */ DUK__MK_LBP_FLAGS(DUK__BP_POSTFIX, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_DECREMENT */ DUK__MK_LBP(DUK__BP_SHIFT), /* DUK_TOK_ALSHIFT */ DUK__MK_LBP(DUK__BP_SHIFT), /* DUK_TOK_ARSHIFT */ DUK__MK_LBP(DUK__BP_SHIFT), /* DUK_TOK_RSHIFT */ DUK__MK_LBP(DUK__BP_BAND), /* DUK_TOK_BAND */ DUK__MK_LBP(DUK__BP_BOR), /* DUK_TOK_BOR */ DUK__MK_LBP(DUK__BP_BXOR), /* DUK_TOK_BXOR */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_LNOT */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_BNOT */ DUK__MK_LBP(DUK__BP_LAND), /* DUK_TOK_LAND */ DUK__MK_LBP(DUK__BP_LOR), /* DUK_TOK_LOR */ DUK__MK_LBP(DUK__BP_CONDITIONAL), /* DUK_TOK_QUESTION */ DUK__MK_LBP(DUK__BP_INVALID), /* DUK_TOK_COLON */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_EQUALSIGN */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_ADD_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_SUB_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_MUL_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_DIV_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_MOD_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_EXP_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_ALSHIFT_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_ARSHIFT_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_RSHIFT_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_BAND_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_BOR_EQ */ DUK__MK_LBP(DUK__BP_ASSIGNMENT), /* DUK_TOK_BXOR_EQ */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_NUMBER */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_STRING */ DUK__MK_LBP_FLAGS(DUK__BP_INVALID, DUK__TOKEN_LBP_FLAG_NO_REGEXP), /* DUK_TOK_REGEXP */ }; /* * Misc helpers */ DUK_LOCAL void duk__comp_recursion_increase(duk_compiler_ctx *comp_ctx) { DUK_ASSERT(comp_ctx != NULL); DUK_ASSERT(comp_ctx->recursion_depth >= 0); if (comp_ctx->recursion_depth >= comp_ctx->recursion_limit) { DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_COMPILER_RECURSION_LIMIT); DUK_WO_NORETURN(return;); } comp_ctx->recursion_depth++; } DUK_LOCAL void duk__comp_recursion_decrease(duk_compiler_ctx *comp_ctx) { DUK_ASSERT(comp_ctx != NULL); DUK_ASSERT(comp_ctx->recursion_depth > 0); comp_ctx->recursion_depth--; } DUK_LOCAL duk_bool_t duk__hstring_is_eval_or_arguments(duk_compiler_ctx *comp_ctx, duk_hstring *h) { DUK_UNREF(comp_ctx); DUK_ASSERT(h != NULL); return DUK_HSTRING_HAS_EVAL_OR_ARGUMENTS(h); } DUK_LOCAL duk_bool_t duk__hstring_is_eval_or_arguments_in_strict_mode(duk_compiler_ctx *comp_ctx, duk_hstring *h) { DUK_ASSERT(h != NULL); return (comp_ctx->curr_func.is_strict && DUK_HSTRING_HAS_EVAL_OR_ARGUMENTS(h)); } /* * Parser duk__advance() token eating functions */ /* XXX: valstack handling is awkward. Add a valstack helper which * avoids dup():ing; valstack_copy(src, dst)? */ DUK_LOCAL void duk__advance_helper(duk_compiler_ctx *comp_ctx, duk_small_int_t expect) { duk_hthread *thr = comp_ctx->thr; duk_bool_t regexp; DUK_ASSERT_DISABLE(comp_ctx->curr_token.t >= 0); /* unsigned */ DUK_ASSERT(comp_ctx->curr_token.t <= DUK_TOK_MAXVAL); /* MAXVAL is inclusive */ /* * Use current token to decide whether a RegExp can follow. * * We can use either 't' or 't_nores'; the latter would not * recognize keywords. Some keywords can be followed by a * RegExp (e.g. "return"), so using 't' is better. This is * not trivial, see doc/compiler.rst. */ regexp = 1; if (duk__token_lbp[comp_ctx->curr_token.t] & DUK__TOKEN_LBP_FLAG_NO_REGEXP) { regexp = 0; } if (comp_ctx->curr_func.reject_regexp_in_adv) { comp_ctx->curr_func.reject_regexp_in_adv = 0; regexp = 0; } if (comp_ctx->curr_func.allow_regexp_in_adv) { comp_ctx->curr_func.allow_regexp_in_adv = 0; regexp = 1; } if (expect >= 0 && comp_ctx->curr_token.t != (duk_small_uint_t) expect) { DUK_D(DUK_DPRINT("parse error: expect=%ld, got=%ld", (long) expect, (long) comp_ctx->curr_token.t)); DUK_ERROR_SYNTAX(thr, DUK_STR_PARSE_ERROR); DUK_WO_NORETURN(return;); } /* make current token the previous; need to fiddle with valstack "backing store" */ duk_memcpy(&comp_ctx->prev_token, &comp_ctx->curr_token, sizeof(duk_token)); duk_copy(thr, comp_ctx->tok11_idx, comp_ctx->tok21_idx); duk_copy(thr, comp_ctx->tok12_idx, comp_ctx->tok22_idx); /* parse new token */ duk_lexer_parse_js_input_element(&comp_ctx->lex, &comp_ctx->curr_token, comp_ctx->curr_func.is_strict, regexp); DUK_DDD(DUK_DDDPRINT("advance: curr: tok=%ld/%ld,%ld,term=%ld,%!T,%!T " "prev: tok=%ld/%ld,%ld,term=%ld,%!T,%!T", (long) comp_ctx->curr_token.t, (long) comp_ctx->curr_token.t_nores, (long) comp_ctx->curr_token.start_line, (long) comp_ctx->curr_token.lineterm, (duk_tval *) duk_get_tval(thr, comp_ctx->tok11_idx), (duk_tval *) duk_get_tval(thr, comp_ctx->tok12_idx), (long) comp_ctx->prev_token.t, (long) comp_ctx->prev_token.t_nores, (long) comp_ctx->prev_token.start_line, (long) comp_ctx->prev_token.lineterm, (duk_tval *) duk_get_tval(thr, comp_ctx->tok21_idx), (duk_tval *) duk_get_tval(thr, comp_ctx->tok22_idx))); } /* advance, expecting current token to be a specific token; parse next token in regexp context */ DUK_LOCAL void duk__advance_expect(duk_compiler_ctx *comp_ctx, duk_small_int_t expect) { duk__advance_helper(comp_ctx, expect); } /* advance, whatever the current token is; parse next token in regexp context */ DUK_LOCAL void duk__advance(duk_compiler_ctx *comp_ctx) { duk__advance_helper(comp_ctx, -1); } /* * Helpers for duk_compiler_func. */ /* init function state: inits valstack allocations */ DUK_LOCAL void duk__init_func_valstack_slots(duk_compiler_ctx *comp_ctx) { duk_compiler_func *func = &comp_ctx->curr_func; duk_hthread *thr = comp_ctx->thr; duk_idx_t entry_top; entry_top = duk_get_top(thr); duk_memzero(func, sizeof(*func)); /* intentional overlap with earlier memzero */ #if defined(DUK_USE_EXPLICIT_NULL_INIT) func->h_name = NULL; func->h_consts = NULL; func->h_funcs = NULL; func->h_decls = NULL; func->h_labelnames = NULL; func->h_labelinfos = NULL; func->h_argnames = NULL; func->h_varmap = NULL; #endif duk_require_stack(thr, DUK__FUNCTION_INIT_REQUIRE_SLOTS); DUK_BW_INIT_PUSHBUF(thr, &func->bw_code, DUK__BC_INITIAL_INSTS * sizeof(duk_compiler_instr)); /* code_idx = entry_top + 0 */ duk_push_bare_array(thr); func->consts_idx = entry_top + 1; func->h_consts = DUK_GET_HOBJECT_POSIDX(thr, entry_top + 1); DUK_ASSERT(func->h_consts != NULL); duk_push_bare_array(thr); func->funcs_idx = entry_top + 2; func->h_funcs = DUK_GET_HOBJECT_POSIDX(thr, entry_top + 2); DUK_ASSERT(func->h_funcs != NULL); DUK_ASSERT(func->fnum_next == 0); duk_push_bare_array(thr); func->decls_idx = entry_top + 3; func->h_decls = DUK_GET_HOBJECT_POSIDX(thr, entry_top + 3); DUK_ASSERT(func->h_decls != NULL); duk_push_bare_array(thr); func->labelnames_idx = entry_top + 4; func->h_labelnames = DUK_GET_HOBJECT_POSIDX(thr, entry_top + 4); DUK_ASSERT(func->h_labelnames != NULL); duk_push_dynamic_buffer(thr, 0); func->labelinfos_idx = entry_top + 5; func->h_labelinfos = (duk_hbuffer_dynamic *) duk_known_hbuffer(thr, entry_top + 5); DUK_ASSERT(func->h_labelinfos != NULL); DUK_ASSERT(DUK_HBUFFER_HAS_DYNAMIC(func->h_labelinfos) && !DUK_HBUFFER_HAS_EXTERNAL(func->h_labelinfos)); duk_push_bare_array(thr); func->argnames_idx = entry_top + 6; func->h_argnames = DUK_GET_HOBJECT_POSIDX(thr, entry_top + 6); DUK_ASSERT(func->h_argnames != NULL); duk_push_bare_object(thr); func->varmap_idx = entry_top + 7; func->h_varmap = DUK_GET_HOBJECT_POSIDX(thr, entry_top + 7); DUK_ASSERT(func->h_varmap != NULL); } /* reset function state (prepare for pass 2) */ DUK_LOCAL void duk__reset_func_for_pass2(duk_compiler_ctx *comp_ctx) { duk_compiler_func *func = &comp_ctx->curr_func; duk_hthread *thr = comp_ctx->thr; /* reset bytecode buffer but keep current size; pass 2 will * require same amount or more. */ DUK_BW_RESET_SIZE(thr, &func->bw_code); duk_set_length(thr, func->consts_idx, 0); /* keep func->h_funcs; inner functions are not reparsed to avoid O(depth^2) parsing */ func->fnum_next = 0; /* duk_set_length(thr, func->funcs_idx, 0); */ duk_set_length(thr, func->labelnames_idx, 0); duk_hbuffer_reset(thr, func->h_labelinfos); /* keep func->h_argnames; it is fixed for all passes */ /* truncated in case pass 3 needed */ duk_push_bare_object(thr); duk_replace(thr, func->varmap_idx); func->h_varmap = DUK_GET_HOBJECT_POSIDX(thr, func->varmap_idx); DUK_ASSERT(func->h_varmap != NULL); } /* cleanup varmap from any null entries, compact it, etc; returns number * of final entries after cleanup. */ DUK_LOCAL duk_int_t duk__cleanup_varmap(duk_compiler_ctx *comp_ctx) { duk_hthread *thr = comp_ctx->thr; duk_hobject *h_varmap; duk_hstring *h_key; duk_tval *tv; duk_uint32_t i, e_next; duk_int_t ret; /* [ ... varmap ] */ h_varmap = DUK_GET_HOBJECT_NEGIDX(thr, -1); DUK_ASSERT(h_varmap != NULL); ret = 0; e_next = DUK_HOBJECT_GET_ENEXT(h_varmap); for (i = 0; i < e_next; i++) { h_key = DUK_HOBJECT_E_GET_KEY(thr->heap, h_varmap, i); if (!h_key) { continue; } DUK_ASSERT(!DUK_HOBJECT_E_SLOT_IS_ACCESSOR(thr->heap, h_varmap, i)); /* The entries can either be register numbers or 'null' values. * Thus, no need to DECREF them and get side effects. DECREF'ing * the keys (strings) can cause memory to be freed but no side * effects as strings don't have finalizers. This is why we can * rely on the object properties not changing from underneath us. */ tv = DUK_HOBJECT_E_GET_VALUE_TVAL_PTR(thr->heap, h_varmap, i); if (!DUK_TVAL_IS_NUMBER(tv)) { DUK_ASSERT(!DUK_TVAL_IS_HEAP_ALLOCATED(tv)); DUK_HOBJECT_E_SET_KEY(thr->heap, h_varmap, i, NULL); DUK_HSTRING_DECREF(thr, h_key); /* when key is NULL, value is garbage so no need to set */ } else { ret++; } } duk_compact_m1(thr); return ret; } /* Convert duk_compiler_func into a function template, leaving the result * on top of stack. */ /* XXX: awkward and bloated asm -- use faster internal accesses */ DUK_LOCAL void duk__convert_to_func_template(duk_compiler_ctx *comp_ctx) { duk_compiler_func *func = &comp_ctx->curr_func; duk_hthread *thr = comp_ctx->thr; duk_hcompfunc *h_res; duk_hbuffer_fixed *h_data; duk_size_t consts_count; duk_size_t funcs_count; duk_size_t code_count; duk_size_t code_size; duk_size_t data_size; duk_size_t i; duk_tval *p_const; duk_hobject **p_func; duk_instr_t *p_instr; duk_compiler_instr *q_instr; duk_tval *tv; duk_bool_t keep_varmap; duk_bool_t keep_formals; #if !defined(DUK_USE_DEBUGGER_SUPPORT) duk_size_t formals_length; #endif DUK_DDD(DUK_DDDPRINT("converting duk_compiler_func to function/template")); /* * Push result object and init its flags */ /* Valstack should suffice here, required on function valstack init */ h_res = duk_push_hcompfunc(thr); DUK_ASSERT(h_res != NULL); DUK_ASSERT(DUK_HOBJECT_GET_PROTOTYPE(thr->heap, (duk_hobject *) h_res) == thr->builtins[DUK_BIDX_FUNCTION_PROTOTYPE]); DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, (duk_hobject *) h_res, NULL); /* Function templates are "bare objects". */ if (func->is_function) { DUK_DDD(DUK_DDDPRINT("function -> set NEWENV")); DUK_HOBJECT_SET_NEWENV((duk_hobject *) h_res); if (!func->is_arguments_shadowed) { /* arguments object would be accessible; note that shadowing * bindings are arguments or function declarations, neither * of which are deletable, so this is safe. */ if (func->id_access_arguments || func->may_direct_eval) { DUK_DDD(DUK_DDDPRINT("function may access 'arguments' object directly or " "indirectly -> set CREATEARGS")); DUK_HOBJECT_SET_CREATEARGS((duk_hobject *) h_res); } } } else if (func->is_eval && func->is_strict) { DUK_DDD(DUK_DDDPRINT("strict eval code -> set NEWENV")); DUK_HOBJECT_SET_NEWENV((duk_hobject *) h_res); } else { /* non-strict eval: env is caller's env or global env (direct vs. indirect call) * global code: env is is global env */ DUK_DDD(DUK_DDDPRINT("non-strict eval code or global code -> no NEWENV")); DUK_ASSERT(!DUK_HOBJECT_HAS_NEWENV((duk_hobject *) h_res)); } #if defined(DUK_USE_FUNC_NAME_PROPERTY) if (func->is_function && func->is_namebinding && func->h_name != NULL) { /* Object literal set/get functions have a name (property * name) but must not have a lexical name binding, see * test-bug-getset-func-name.js. */ DUK_DDD(DUK_DDDPRINT("function expression with a name -> set NAMEBINDING")); DUK_HOBJECT_SET_NAMEBINDING((duk_hobject *) h_res); } #endif if (func->is_strict) { DUK_DDD(DUK_DDDPRINT("function is strict -> set STRICT")); DUK_HOBJECT_SET_STRICT((duk_hobject *) h_res); } if (func->is_notail) { DUK_DDD(DUK_DDDPRINT("function is notail -> set NOTAIL")); DUK_HOBJECT_SET_NOTAIL((duk_hobject *) h_res); } if (func->is_constructable) { DUK_DDD(DUK_DDDPRINT("function is constructable -> set CONSTRUCTABLE")); DUK_HOBJECT_SET_CONSTRUCTABLE((duk_hobject *) h_res); } /* * Build function fixed size 'data' buffer, which contains bytecode, * constants, and inner function references. * * During the building phase 'data' is reachable but incomplete. * Only incref's occur during building (no refzero or GC happens), * so the building process is atomic. */ consts_count = duk_hobject_get_length(thr, func->h_consts); funcs_count = duk_hobject_get_length(thr, func->h_funcs) / 3; code_count = DUK_BW_GET_SIZE(thr, &func->bw_code) / sizeof(duk_compiler_instr); code_size = code_count * sizeof(duk_instr_t); data_size = consts_count * sizeof(duk_tval) + funcs_count * sizeof(duk_hobject *) + code_size; DUK_DDD(DUK_DDDPRINT("consts_count=%ld, funcs_count=%ld, code_size=%ld -> " "data_size=%ld*%ld + %ld*%ld + %ld = %ld", (long) consts_count, (long) funcs_count, (long) code_size, (long) consts_count, (long) sizeof(duk_tval), (long) funcs_count, (long) sizeof(duk_hobject *), (long) code_size, (long) data_size)); duk_push_fixed_buffer_nozero(thr, data_size); h_data = (duk_hbuffer_fixed *) (void *) duk_known_hbuffer(thr, -1); DUK_HCOMPFUNC_SET_DATA(thr->heap, h_res, (duk_hbuffer *) h_data); DUK_HEAPHDR_INCREF(thr, h_data); p_const = (duk_tval *) (void *) DUK_HBUFFER_FIXED_GET_DATA_PTR(thr->heap, h_data); for (i = 0; i < consts_count; i++) { DUK_ASSERT(i <= DUK_UARRIDX_MAX); /* const limits */ tv = duk_hobject_find_array_entry_tval_ptr(thr->heap, func->h_consts, (duk_uarridx_t) i); DUK_ASSERT(tv != NULL); DUK_TVAL_SET_TVAL(p_const, tv); p_const++; DUK_TVAL_INCREF(thr, tv); /* may be a string constant */ DUK_DDD(DUK_DDDPRINT("constant: %!T", (duk_tval *) tv)); } p_func = (duk_hobject **) p_const; DUK_HCOMPFUNC_SET_FUNCS(thr->heap, h_res, p_func); for (i = 0; i < funcs_count; i++) { duk_hobject *h; DUK_ASSERT(i * 3 <= DUK_UARRIDX_MAX); /* func limits */ tv = duk_hobject_find_array_entry_tval_ptr(thr->heap, func->h_funcs, (duk_uarridx_t) (i * 3)); DUK_ASSERT(tv != NULL); DUK_ASSERT(DUK_TVAL_IS_OBJECT(tv)); h = DUK_TVAL_GET_OBJECT(tv); DUK_ASSERT(h != NULL); DUK_ASSERT(DUK_HOBJECT_IS_COMPFUNC(h)); *p_func++ = h; DUK_HOBJECT_INCREF(thr, h); DUK_DDD(DUK_DDDPRINT("inner function: %p -> %!iO", (void *) h, (duk_heaphdr *) h)); } p_instr = (duk_instr_t *) p_func; DUK_HCOMPFUNC_SET_BYTECODE(thr->heap, h_res, p_instr); /* copy bytecode instructions one at a time */ q_instr = (duk_compiler_instr *) (void *) DUK_BW_GET_BASEPTR(thr, &func->bw_code); for (i = 0; i < code_count; i++) { p_instr[i] = q_instr[i].ins; } /* Note: 'q_instr' is still used below */ DUK_ASSERT((duk_uint8_t *) (p_instr + code_count) == DUK_HBUFFER_FIXED_GET_DATA_PTR(thr->heap, h_data) + data_size); duk_pop(thr); /* 'data' (and everything in it) is reachable through h_res now */ /* * Init non-property result fields * * 'nregs' controls how large a register frame is allocated. * * 'nargs' controls how many formal arguments are written to registers: * r0, ... r(nargs-1). The remaining registers are initialized to * undefined. */ DUK_ASSERT(func->temp_max >= 0); h_res->nregs = (duk_uint16_t) func->temp_max; h_res->nargs = (duk_uint16_t) duk_hobject_get_length(thr, func->h_argnames); DUK_ASSERT(h_res->nregs >= h_res->nargs); /* pass2 allocation handles this */ #if defined(DUK_USE_DEBUGGER_SUPPORT) h_res->start_line = (duk_uint32_t) func->min_line; h_res->end_line = (duk_uint32_t) func->max_line; #endif /* * Init object properties * * Properties should be added in decreasing order of access frequency. * (Not very critical for function templates.) */ DUK_DDD(DUK_DDDPRINT("init function properties")); /* [ ... res ] */ /* _Varmap: omitted if function is guaranteed not to do a slow path * identifier access that might be caught by locally declared variables. * The varmap can also be omitted if it turns out empty of actual * register mappings after a cleanup. When debugging is enabled, we * always need the varmap to be able to lookup variables at any point. */ #if defined(DUK_USE_DEBUGGER_SUPPORT) DUK_DD(DUK_DDPRINT("keeping _Varmap because debugger support is enabled")); keep_varmap = 1; #else if (func->id_access_slow_own || /* directly uses slow accesses that may match own variables */ func->id_access_arguments || /* accesses 'arguments' directly */ func->may_direct_eval || /* may indirectly slow access through a direct eval */ funcs_count > 0) { /* has inner functions which may slow access (XXX: this can be optimized by looking at the inner functions) */ DUK_DD(DUK_DDPRINT("keeping _Varmap because of direct eval, slow path access that may match local variables, or presence of inner functions")); keep_varmap = 1; } else { DUK_DD(DUK_DDPRINT("dropping _Varmap")); keep_varmap = 0; } #endif if (keep_varmap) { duk_int_t num_used; duk_dup(thr, func->varmap_idx); num_used = duk__cleanup_varmap(comp_ctx); DUK_DDD(DUK_DDDPRINT("cleaned up varmap: %!T (num_used=%ld)", (duk_tval *) duk_get_tval(thr, -1), (long) num_used)); if (num_used > 0) { duk_xdef_prop_stridx_short(thr, -2, DUK_STRIDX_INT_VARMAP, DUK_PROPDESC_FLAGS_NONE); } else { DUK_DD(DUK_DDPRINT("varmap is empty after cleanup -> no need to add")); duk_pop(thr); } } /* _Formals: omitted if function is guaranteed not to need a (non-strict) * arguments object, and _Formals.length matches nargs exactly. * * Non-arrow functions can't see an outer function's 'argument' binding * (because they have their own), but arrow functions can. When arrow * functions are added, this condition would need to be added: * inner_arrow_funcs_count > 0 inner arrow functions may access 'arguments' */ #if defined(DUK_USE_DEBUGGER_SUPPORT) DUK_DD(DUK_DDPRINT("keeping _Formals because debugger support is enabled")); keep_formals = 1; #else formals_length = duk_get_length(thr, func->argnames_idx); if (formals_length != (duk_size_t) h_res->nargs) { /* Nargs not enough for closure .length: keep _Formals regardless * of its length. Shouldn't happen in practice at the moment. */ DUK_DD(DUK_DDPRINT("keeping _Formals because _Formals.length != nargs")); keep_formals = 1; } else if ((func->id_access_arguments || func->may_direct_eval) && (formals_length > 0)) { /* Direct eval (may access 'arguments') or accesses 'arguments' * explicitly: keep _Formals unless it is zero length. */ DUK_DD(DUK_DDPRINT("keeping _Formals because of direct eval or explicit access to 'arguments', and _Formals.length != 0")); keep_formals = 1; } else { DUK_DD(DUK_DDPRINT("omitting _Formals, nargs matches _Formals.length, so no properties added")); keep_formals = 0; } #endif if (keep_formals) { duk_dup(thr, func->argnames_idx); duk_xdef_prop_stridx_short(thr, -2, DUK_STRIDX_INT_FORMALS, DUK_PROPDESC_FLAGS_NONE); } /* name */ #if defined(DUK_USE_FUNC_NAME_PROPERTY) if (func->h_name) { duk_push_hstring(thr, func->h_name); DUK_DD(DUK_DDPRINT("setting function template .name to %!T", duk_get_tval(thr, -1))); duk_xdef_prop_stridx_short(thr, -2, DUK_STRIDX_NAME, DUK_PROPDESC_FLAGS_NONE); } #endif /* DUK_USE_FUNC_NAME_PROPERTY */ /* _Source */ #if defined(DUK_USE_NONSTD_FUNC_SOURCE_PROPERTY) if (0) { /* XXX: Currently function source code is not stored, as it is not * required by the standard. Source code should not be stored by * default (user should enable it explicitly), and the source should * probably be compressed with a trivial text compressor; average * compression of 20-30% is quite easy to achieve even with a trivial * compressor (RLE + backwards lookup). * * Debugging needs source code to be useful: sometimes input code is * not found in files as it may be generated and then eval()'d, given * by dynamic C code, etc. * * Other issues: * * - Need tokenizer indices for start and end to substring * - Always normalize function declaration part? * - If we keep _Formals, only need to store body */ /* * For global or eval code this is straightforward. For functions * created with the Function constructor we only get the source for * the body and must manufacture the "function ..." part. * * For instance, for constructed functions (v8): * * > a = new Function("foo", "bar", "print(foo)"); * [Function] * > a.toString() * 'function anonymous(foo,bar) {\nprint(foo)\n}' * * Similarly for e.g. getters (v8): * * > x = { get a(foo,bar) { print(foo); } } * { a: [Getter] } * > Object.getOwnPropertyDescriptor(x, 'a').get.toString() * 'function a(foo,bar) { print(foo); }' */ #if 0 duk_push_literal(thr, "XXX"); duk_xdef_prop_stridx_short(thr, -2, DUK_STRIDX_INT_SOURCE, DUK_PROPDESC_FLAGS_NONE); #endif } #endif /* DUK_USE_NONSTD_FUNC_SOURCE_PROPERTY */ /* _Pc2line */ #if defined(DUK_USE_PC2LINE) if (1) { /* * Size-optimized pc->line mapping. */ DUK_ASSERT(code_count <= DUK_COMPILER_MAX_BYTECODE_LENGTH); duk_hobject_pc2line_pack(thr, q_instr, (duk_uint_fast32_t) code_count); /* -> pushes fixed buffer */ duk_xdef_prop_stridx_short(thr, -2, DUK_STRIDX_INT_PC2LINE, DUK_PROPDESC_FLAGS_NONE); /* XXX: if assertions enabled, walk through all valid PCs * and check line mapping. */ } #endif /* DUK_USE_PC2LINE */ /* fileName */ #if defined(DUK_USE_FUNC_FILENAME_PROPERTY) if (comp_ctx->h_filename) { /* * Source filename (or equivalent), for identifying thrown errors. */ duk_push_hstring(thr, comp_ctx->h_filename); duk_xdef_prop_stridx_short(thr, -2, DUK_STRIDX_FILE_NAME, DUK_PROPDESC_FLAGS_NONE); } #endif DUK_DD(DUK_DDPRINT("converted function: %!ixT", (duk_tval *) duk_get_tval(thr, -1))); /* * Compact the function template. */ duk_compact_m1(thr); /* * Debug dumping */ #if defined(DUK_USE_DEBUG_LEVEL) && (DUK_USE_DEBUG_LEVEL >= 2) { duk_hcompfunc *h; duk_instr_t *p, *p_start, *p_end; h = (duk_hcompfunc *) duk_get_hobject(thr, -1); p_start = (duk_instr_t *) DUK_HCOMPFUNC_GET_CODE_BASE(thr->heap, h); p_end = (duk_instr_t *) DUK_HCOMPFUNC_GET_CODE_END(thr->heap, h); p = p_start; while (p < p_end) { DUK_DDD(DUK_DDDPRINT("BC %04ld: %!I ; 0x%08lx op=%ld (%!X) a=%ld b=%ld c=%ld", (long) (p - p_start), (duk_instr_t) (*p), (unsigned long) (*p), (long) DUK_DEC_OP(*p), (long) DUK_DEC_OP(*p), (long) DUK_DEC_A(*p), (long) DUK_DEC_B(*p), (long) DUK_DEC_C(*p))); p++; } } #endif } /* * Code emission helpers * * Some emission helpers understand the range of target and source reg/const * values and automatically emit shuffling code if necessary. This is the * case when the slot in question (A, B, C) is used in the standard way and * for opcodes the emission helpers explicitly understand (like DUK_OP_MPUTOBJ). * * The standard way is that: * - slot A is a target register * - slot B is a source register/constant * - slot C is a source register/constant * * If a slot is used in a non-standard way the caller must indicate this * somehow. If a slot is used as a target instead of a source (or vice * versa), this can be indicated with a flag to trigger proper shuffling * (e.g. DUK__EMIT_FLAG_B_IS_TARGET). If the value in the slot is not * register/const related at all, the caller must ensure that the raw value * fits into the corresponding slot so as to not trigger shuffling. The * caller must set a "no shuffle" flag to ensure compilation fails if * shuffling were to be triggered because of an internal error. * * For slots B and C the raw slot size is 9 bits but one bit is reserved for * the reg/const indicator. To use the full 9-bit range for a raw value, * shuffling must be disabled with the DUK__EMIT_FLAG_NO_SHUFFLE_{B,C} flag. * Shuffling is only done for A, B, and C slots, not the larger BC or ABC slots. * * There is call handling specific understanding in the A-B-C emitter to * convert call setup and call instructions into indirect ones if necessary. */ /* Code emission flags, passed in the 'opcode' field. Opcode + flags * fit into 16 bits for now, so use duk_small_uint_t. */ #define DUK__EMIT_FLAG_NO_SHUFFLE_A (1 << 8) #define DUK__EMIT_FLAG_NO_SHUFFLE_B (1 << 9) #define DUK__EMIT_FLAG_NO_SHUFFLE_C (1 << 10) #define DUK__EMIT_FLAG_A_IS_SOURCE (1 << 11) /* slot A is a source (default: target) */ #define DUK__EMIT_FLAG_B_IS_TARGET (1 << 12) /* slot B is a target (default: source) */ #define DUK__EMIT_FLAG_C_IS_TARGET (1 << 13) /* slot C is a target (default: source) */ #define DUK__EMIT_FLAG_BC_REGCONST (1 << 14) /* slots B and C are reg/const */ #define DUK__EMIT_FLAG_RESERVE_JUMPSLOT (1 << 15) /* reserve a jumpslot after instr before target spilling, used for NEXTENUM */ /* XXX: macro smaller than call? */ DUK_LOCAL duk_int_t duk__get_current_pc(duk_compiler_ctx *comp_ctx) { duk_compiler_func *func; func = &comp_ctx->curr_func; return (duk_int_t) (DUK_BW_GET_SIZE(comp_ctx->thr, &func->bw_code) / sizeof(duk_compiler_instr)); } DUK_LOCAL duk_compiler_instr *duk__get_instr_ptr(duk_compiler_ctx *comp_ctx, duk_int_t pc) { DUK_ASSERT(pc >= 0); DUK_ASSERT((duk_size_t) pc < (duk_size_t) (DUK_BW_GET_SIZE(comp_ctx->thr, &comp_ctx->curr_func.bw_code) / sizeof(duk_compiler_instr))); return ((duk_compiler_instr *) (void *) DUK_BW_GET_BASEPTR(comp_ctx->thr, &comp_ctx->curr_func.bw_code)) + pc; } /* emit instruction; could return PC but that's not needed in the majority * of cases. */ DUK_LOCAL void duk__emit(duk_compiler_ctx *comp_ctx, duk_instr_t ins) { #if defined(DUK_USE_PC2LINE) duk_int_t line; #endif duk_compiler_instr *instr; DUK_DDD(DUK_DDDPRINT("duk__emit: 0x%08lx curr_token.start_line=%ld prev_token.start_line=%ld pc=%ld --> %!I", (unsigned long) ins, (long) comp_ctx->curr_token.start_line, (long) comp_ctx->prev_token.start_line, (long) duk__get_current_pc(comp_ctx), (duk_instr_t) ins)); instr = (duk_compiler_instr *) (void *) DUK_BW_ENSURE_GETPTR(comp_ctx->thr, &comp_ctx->curr_func.bw_code, sizeof(duk_compiler_instr)); DUK_BW_ADD_PTR(comp_ctx->thr, &comp_ctx->curr_func.bw_code, sizeof(duk_compiler_instr)); #if defined(DUK_USE_PC2LINE) /* The line number tracking is a bit inconsistent right now, which * affects debugger accuracy. Mostly call sites emit opcodes when * they have parsed a token (say a terminating semicolon) and called * duk__advance(). In this case the line number of the previous * token is the most accurate one (except in prologue where * prev_token.start_line is 0). This is probably not 100% correct * right now. */ /* approximation, close enough */ line = comp_ctx->prev_token.start_line; if (line == 0) { line = comp_ctx->curr_token.start_line; } #endif instr->ins = ins; #if defined(DUK_USE_PC2LINE) instr->line = (duk_uint32_t) line; #endif #if defined(DUK_USE_DEBUGGER_SUPPORT) if (line < comp_ctx->curr_func.min_line) { comp_ctx->curr_func.min_line = line; } if (line > comp_ctx->curr_func.max_line) { comp_ctx->curr_func.max_line = line; } #endif /* Limit checks for bytecode byte size and line number. */ if (DUK_UNLIKELY(DUK_BW_GET_SIZE(comp_ctx->thr, &comp_ctx->curr_func.bw_code) > DUK_USE_ESBC_MAX_BYTES)) { goto fail_bc_limit; } #if defined(DUK_USE_PC2LINE) && defined(DUK_USE_ESBC_LIMITS) #if defined(DUK_USE_BUFLEN16) /* Buffer length is bounded to 0xffff automatically, avoid compile warning. */ if (DUK_UNLIKELY(line > DUK_USE_ESBC_MAX_LINENUMBER)) { goto fail_bc_limit; } #else if (DUK_UNLIKELY(line > DUK_USE_ESBC_MAX_LINENUMBER)) { goto fail_bc_limit; } #endif #endif return; fail_bc_limit: DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_BYTECODE_LIMIT); DUK_WO_NORETURN(return;); } /* Update function min/max line from current token. Needed to improve * function line range information for debugging, so that e.g. opening * curly brace is covered by line range even when no opcodes are emitted * for the line containing the brace. */ DUK_LOCAL void duk__update_lineinfo_currtoken(duk_compiler_ctx *comp_ctx) { #if defined(DUK_USE_DEBUGGER_SUPPORT) duk_int_t line; line = comp_ctx->curr_token.start_line; if (line == 0) { return; } if (line < comp_ctx->curr_func.min_line) { comp_ctx->curr_func.min_line = line; } if (line > comp_ctx->curr_func.max_line) { comp_ctx->curr_func.max_line = line; } #else DUK_UNREF(comp_ctx); #endif } DUK_LOCAL void duk__emit_op_only(duk_compiler_ctx *comp_ctx, duk_small_uint_t op) { duk__emit(comp_ctx, DUK_ENC_OP_ABC(op, 0)); } /* Important main primitive. */ DUK_LOCAL void duk__emit_a_b_c(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a, duk_regconst_t b, duk_regconst_t c) { duk_instr_t ins = 0; duk_int_t a_out = -1; duk_int_t b_out = -1; duk_int_t c_out = -1; duk_int_t tmp; duk_small_uint_t op = op_flags & 0xffU; DUK_DDD(DUK_DDDPRINT("emit: op_flags=%04lx, a=%ld, b=%ld, c=%ld", (unsigned long) op_flags, (long) a, (long) b, (long) c)); /* We could rely on max temp/const checks: if they don't exceed BC * limit, nothing here can either (just asserts would be enough). * Currently we check for the limits, which provides additional * protection against creating invalid bytecode due to compiler * bugs. */ DUK_ASSERT_DISABLE((op_flags & 0xff) >= DUK_BC_OP_MIN); /* unsigned */ DUK_ASSERT((op_flags & 0xff) <= DUK_BC_OP_MAX); DUK_ASSERT(DUK__ISREG(a)); DUK_ASSERT(b != -1); /* Not 'none'. */ DUK_ASSERT(c != -1); /* Not 'none'. */ /* Input shuffling happens before the actual operation, while output * shuffling happens afterwards. Output shuffling decisions are still * made at the same time to reduce branch clutter; output shuffle decisions * are recorded into X_out variables. */ /* Slot A: currently no support for reg/const. */ #if defined(DUK_USE_SHUFFLE_TORTURE) if (a <= DUK_BC_A_MAX && (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_A)) { #else if (a <= DUK_BC_A_MAX) { #endif ; } else if (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_A) { DUK_D(DUK_DPRINT("out of regs: 'a' (reg) needs shuffling but shuffle prohibited, a: %ld", (long) a)); goto error_outofregs; } else if (a <= DUK_BC_BC_MAX) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle1; if (op_flags & DUK__EMIT_FLAG_A_IS_SOURCE) { duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_LDREG, tmp, a)); } else { /* Output shuffle needed after main operation */ a_out = a; /* The DUK_OP_CSVAR output shuffle assumes shuffle registers are * consecutive. */ DUK_ASSERT((comp_ctx->curr_func.shuffle1 == 0 && comp_ctx->curr_func.shuffle2 == 0) || (comp_ctx->curr_func.shuffle2 == comp_ctx->curr_func.shuffle1 + 1)); if (op == DUK_OP_CSVAR) { /* For CSVAR the limit is one smaller because output shuffle * must be able to express 'a + 1' in BC. */ if (a + 1 > DUK_BC_BC_MAX) { goto error_outofregs; } } } a = tmp; } else { DUK_D(DUK_DPRINT("out of regs: 'a' (reg) needs shuffling but does not fit into BC, a: %ld", (long) a)); goto error_outofregs; } /* Slot B: reg/const support, mapped to bit 0 of opcode. */ if ((b & DUK__CONST_MARKER) != 0) { DUK_ASSERT((op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_B) == 0); DUK_ASSERT((op_flags & DUK__EMIT_FLAG_B_IS_TARGET) == 0); b = b & ~DUK__CONST_MARKER; #if defined(DUK_USE_SHUFFLE_TORTURE) if (0) { #else if (b <= 0xff) { #endif if (op_flags & DUK__EMIT_FLAG_BC_REGCONST) { /* Opcode follows B/C reg/const convention. */ DUK_ASSERT((op & 0x01) == 0); ins |= DUK_ENC_OP_A_B_C(0x01, 0, 0, 0); /* const flag for B */ } else { DUK_D(DUK_DPRINT("B is const, opcode is not B/C reg/const: %x", op_flags)); } } else if (b <= DUK_BC_BC_MAX) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle2; duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_LDCONST, tmp, b)); b = tmp; } else { DUK_D(DUK_DPRINT("out of regs: 'b' (const) needs shuffling but does not fit into BC, b: %ld", (long) b)); goto error_outofregs; } } else { #if defined(DUK_USE_SHUFFLE_TORTURE) if (b <= 0xff && (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_B)) { #else if (b <= 0xff) { #endif ; } else if (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_B) { if (b > DUK_BC_B_MAX) { /* Note: 0xff != DUK_BC_B_MAX */ DUK_D(DUK_DPRINT("out of regs: 'b' (reg) needs shuffling but shuffle prohibited, b: %ld", (long) b)); goto error_outofregs; } } else if (b <= DUK_BC_BC_MAX) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle2; if (op_flags & DUK__EMIT_FLAG_B_IS_TARGET) { /* Output shuffle needed after main operation */ b_out = b; } if (!(op_flags & DUK__EMIT_FLAG_B_IS_TARGET)) { if (op == DUK_OP_MPUTOBJ || op == DUK_OP_MPUTARR) { /* Special handling for MPUTOBJ/MPUTARR shuffling. * For each, slot B identifies the first register of a range * of registers, so normal shuffling won't work. Instead, * an indirect version of the opcode is used. */ DUK_ASSERT((op_flags & DUK__EMIT_FLAG_B_IS_TARGET) == 0); duk__emit_load_int32_noshuffle(comp_ctx, tmp, b); DUK_ASSERT(DUK_OP_MPUTOBJI == DUK_OP_MPUTOBJ + 1); DUK_ASSERT(DUK_OP_MPUTARRI == DUK_OP_MPUTARR + 1); op_flags++; /* indirect opcode follows direct */ } else { duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_LDREG, tmp, b)); } } b = tmp; } else { DUK_D(DUK_DPRINT("out of regs: 'b' (reg) needs shuffling but does not fit into BC, b: %ld", (long) b)); goto error_outofregs; } } /* Slot C: reg/const support, mapped to bit 1 of opcode. */ if ((c & DUK__CONST_MARKER) != 0) { DUK_ASSERT((op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_C) == 0); DUK_ASSERT((op_flags & DUK__EMIT_FLAG_C_IS_TARGET) == 0); c = c & ~DUK__CONST_MARKER; #if defined(DUK_USE_SHUFFLE_TORTURE) if (0) { #else if (c <= 0xff) { #endif if (op_flags & DUK__EMIT_FLAG_BC_REGCONST) { /* Opcode follows B/C reg/const convention. */ DUK_ASSERT((op & 0x02) == 0); ins |= DUK_ENC_OP_A_B_C(0x02, 0, 0, 0); /* const flag for C */ } else { DUK_D(DUK_DPRINT("C is const, opcode is not B/C reg/const: %x", op_flags)); } } else if (c <= DUK_BC_BC_MAX) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle3; duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_LDCONST, tmp, c)); c = tmp; } else { DUK_D(DUK_DPRINT("out of regs: 'c' (const) needs shuffling but does not fit into BC, c: %ld", (long) c)); goto error_outofregs; } } else { #if defined(DUK_USE_SHUFFLE_TORTURE) if (c <= 0xff && (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_C)) { #else if (c <= 0xff) { #endif ; } else if (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_C) { if (c > DUK_BC_C_MAX) { /* Note: 0xff != DUK_BC_C_MAX */ DUK_D(DUK_DPRINT("out of regs: 'c' (reg) needs shuffling but shuffle prohibited, c: %ld", (long) c)); goto error_outofregs; } } else if (c <= DUK_BC_BC_MAX) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle3; if (op_flags & DUK__EMIT_FLAG_C_IS_TARGET) { /* Output shuffle needed after main operation */ c_out = c; } else { duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_LDREG, tmp, c)); } c = tmp; } else { DUK_D(DUK_DPRINT("out of regs: 'c' (reg) needs shuffling but does not fit into BC, c: %ld", (long) c)); goto error_outofregs; } } /* Main operation */ DUK_ASSERT(a >= DUK_BC_A_MIN); DUK_ASSERT(a <= DUK_BC_A_MAX); DUK_ASSERT(b >= DUK_BC_B_MIN); DUK_ASSERT(b <= DUK_BC_B_MAX); DUK_ASSERT(c >= DUK_BC_C_MIN); DUK_ASSERT(c <= DUK_BC_C_MAX); ins |= DUK_ENC_OP_A_B_C(op_flags & 0xff, a, b, c); duk__emit(comp_ctx, ins); /* NEXTENUM needs a jump slot right after the main instruction. * When the JUMP is taken, output spilling is not needed so this * workaround is possible. The jump slot PC is exceptionally * plumbed through comp_ctx to minimize call sites. */ if (op_flags & DUK__EMIT_FLAG_RESERVE_JUMPSLOT) { comp_ctx->emit_jumpslot_pc = duk__get_current_pc(comp_ctx); duk__emit_abc(comp_ctx, DUK_OP_JUMP, 0); } /* Output shuffling: only one output register is realistically possible. * * (Zero would normally be an OK marker value: if the target register * was zero, it would never be shuffled. But with DUK_USE_SHUFFLE_TORTURE * this is no longer true, so use -1 as a marker instead.) */ if (a_out >= 0) { DUK_ASSERT(b_out < 0); DUK_ASSERT(c_out < 0); duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_STREG, a, a_out)); if (op == DUK_OP_CSVAR) { /* Special handling for CSVAR shuffling. The variable lookup * results in a pair in successive * registers so use two shuffle registers and two output * loads. (In practice this is dead code because temp/const * limit is reached first.) */ duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_STREG, a + 1, a_out + 1)); } } else if (b_out >= 0) { DUK_ASSERT(a_out < 0); DUK_ASSERT(c_out < 0); duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_STREG, b, b_out)); } else if (c_out >= 0) { DUK_ASSERT(b_out < 0); DUK_ASSERT(c_out < 0); duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_STREG, c, c_out)); } return; error_outofregs: DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_REG_LIMIT); DUK_WO_NORETURN(return;); } /* For many of the helpers below it'd be technically correct to add * "no shuffle" flags for parameters passed in as zero. For example, * duk__emit_a_b() should call duk__emit_a_b_c() with C set to 0, and * DUK__EMIT_FLAG_NO_SHUFFLE_C added to op_flags. However, since the * C value is 0, it'll never get shuffled so adding the flag is just * unnecessary additional code. This is unfortunately not true for * "shuffle torture" mode which needs special handling. */ DUK_LOCAL void duk__emit_a_b(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a, duk_regconst_t b) { #if defined(DUK_USE_SHUFFLE_TORTURE) op_flags |= DUK__EMIT_FLAG_NO_SHUFFLE_C; #endif duk__emit_a_b_c(comp_ctx, op_flags, a, b, 0); } DUK_LOCAL void duk__emit_b_c(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t b, duk_regconst_t c) { #if defined(DUK_USE_SHUFFLE_TORTURE) op_flags |= DUK__EMIT_FLAG_NO_SHUFFLE_A; #endif duk__emit_a_b_c(comp_ctx, op_flags, 0, b, c); } #if 0 /* unused */ DUK_LOCAL void duk__emit_a(duk_compiler_ctx *comp_ctx, int op_flags, int a) { #if defined(DUK_USE_SHUFFLE_TORTURE) op_flags |= DUK__EMIT_FLAG_NO_SHUFFLE_B | DUK__EMIT_FLAG_NO_SHUFFLE_C; #endif duk__emit_a_b_c(comp_ctx, op_flags, a, 0, 0); } #endif #if 0 /* unused */ DUK_LOCAL void duk__emit_b(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t b) { #if defined(DUK_USE_SHUFFLE_TORTURE) op_flags |= DUK__EMIT_FLAG_NO_SHUFFLE_A | DUK__EMIT_FLAG_NO_SHUFFLE_C; #endif duk__emit_a_b_c(comp_ctx, op_flags, 0, b, 0); } #endif DUK_LOCAL void duk__emit_a_bc(duk_compiler_ctx *comp_ctx, duk_small_uint_t op_flags, duk_regconst_t a, duk_regconst_t bc) { duk_instr_t ins; duk_int_t tmp; /* allow caller to give a const number with the DUK__CONST_MARKER */ DUK_ASSERT(bc != -1); /* Not 'none'. */ bc = bc & (~DUK__CONST_MARKER); DUK_ASSERT_DISABLE((op_flags & 0xff) >= DUK_BC_OP_MIN); /* unsigned */ DUK_ASSERT((op_flags & 0xff) <= DUK_BC_OP_MAX); DUK_ASSERT(bc >= DUK_BC_BC_MIN); DUK_ASSERT(bc <= DUK_BC_BC_MAX); DUK_ASSERT((bc & DUK__CONST_MARKER) == 0); if (bc <= DUK_BC_BC_MAX) { ; } else { /* No BC shuffling now. */ goto error_outofregs; } #if defined(DUK_USE_SHUFFLE_TORTURE) if (a <= DUK_BC_A_MAX && (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_A)) { #else if (a <= DUK_BC_A_MAX) { #endif ins = DUK_ENC_OP_A_BC(op_flags & 0xff, a, bc); duk__emit(comp_ctx, ins); } else if (op_flags & DUK__EMIT_FLAG_NO_SHUFFLE_A) { goto error_outofregs; } else if ((op_flags & 0xf0U) == DUK_OP_CALL0) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle1; duk__emit_load_int32_noshuffle(comp_ctx, tmp, a); op_flags |= DUK_BC_CALL_FLAG_INDIRECT; ins = DUK_ENC_OP_A_BC(op_flags & 0xff, tmp, bc); duk__emit(comp_ctx, ins); } else if (a <= DUK_BC_BC_MAX) { comp_ctx->curr_func.needs_shuffle = 1; tmp = comp_ctx->curr_func.shuffle1; ins = DUK_ENC_OP_A_BC(op_flags & 0xff, tmp, bc); if (op_flags & DUK__EMIT_FLAG_A_IS_SOURCE) { duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_LDREG, tmp, a)); duk__emit(comp_ctx, ins); } else { duk__emit(comp_ctx, ins); duk__emit(comp_ctx, DUK_ENC_OP_A_BC(DUK_OP_STREG, tmp, a)); } } else { goto error_outofregs; } return; error_outofregs: DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_REG_LIMIT); DUK_WO_NORETURN(return;); } DUK_LOCAL void duk__emit_bc(duk_compiler_ctx *comp_ctx, duk_small_uint_t op, duk_regconst_t bc) { #if defined(DUK_USE_SHUFFLE_TORTURE) op |= DUK__EMIT_FLAG_NO_SHUFFLE_A; #endif duk__emit_a_bc(comp_ctx, op, 0, bc); } DUK_LOCAL void duk__emit_abc(duk_compiler_ctx *comp_ctx, duk_small_uint_t op, duk_regconst_t abc) { duk_instr_t ins; DUK_ASSERT_DISABLE(op >= DUK_BC_OP_MIN); /* unsigned */ DUK_ASSERT(op <= DUK_BC_OP_MAX); DUK_ASSERT_DISABLE(abc >= DUK_BC_ABC_MIN); /* unsigned */ DUK_ASSERT(abc <= DUK_BC_ABC_MAX); DUK_ASSERT((abc & DUK__CONST_MARKER) == 0); DUK_ASSERT(abc != -1); /* Not 'none'. */ if (abc <= DUK_BC_ABC_MAX) { ; } else { goto error_outofregs; } ins = DUK_ENC_OP_ABC(op, abc); DUK_DDD(DUK_DDDPRINT("duk__emit_abc: 0x%08lx line=%ld pc=%ld op=%ld (%!X) abc=%ld (%!I)", (unsigned long) ins, (long) comp_ctx->curr_token.start_line, (long) duk__get_current_pc(comp_ctx), (long) op, (long) op, (long) abc, (duk_instr_t) ins)); duk__emit(comp_ctx, ins); return; error_outofregs: DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_REG_LIMIT); DUK_WO_NORETURN(return;); } DUK_LOCAL void duk__emit_load_int32_raw(duk_compiler_ctx *comp_ctx, duk_regconst_t reg, duk_int32_t val, duk_small_uint_t op_flags) { /* XXX: Shuffling support could be implemented here so that LDINT+LDINTX * would only shuffle once (instead of twice). The current code works * though, and has a smaller compiler footprint. */ if ((val >= (duk_int32_t) DUK_BC_BC_MIN - (duk_int32_t) DUK_BC_LDINT_BIAS) && (val <= (duk_int32_t) DUK_BC_BC_MAX - (duk_int32_t) DUK_BC_LDINT_BIAS)) { DUK_DDD(DUK_DDDPRINT("emit LDINT to reg %ld for %ld", (long) reg, (long) val)); duk__emit_a_bc(comp_ctx, DUK_OP_LDINT | op_flags, reg, (duk_regconst_t) (val + (duk_int32_t) DUK_BC_LDINT_BIAS)); } else { duk_int32_t hi = val >> DUK_BC_LDINTX_SHIFT; duk_int32_t lo = val & ((((duk_int32_t) 1) << DUK_BC_LDINTX_SHIFT) - 1); DUK_ASSERT(lo >= 0); DUK_DDD(DUK_DDDPRINT("emit LDINT+LDINTX to reg %ld for %ld -> hi %ld, lo %ld", (long) reg, (long) val, (long) hi, (long) lo)); duk__emit_a_bc(comp_ctx, DUK_OP_LDINT | op_flags, reg, (duk_regconst_t) (hi + (duk_int32_t) DUK_BC_LDINT_BIAS)); duk__emit_a_bc(comp_ctx, DUK_OP_LDINTX | op_flags, reg, (duk_regconst_t) lo); } } DUK_LOCAL void duk__emit_load_int32(duk_compiler_ctx *comp_ctx, duk_regconst_t reg, duk_int32_t val) { duk__emit_load_int32_raw(comp_ctx, reg, val, 0 /*op_flags*/); } #if defined(DUK_USE_SHUFFLE_TORTURE) /* Used by duk__emit*() calls so that we don't shuffle the loadints that * are needed to handle indirect opcodes. */ DUK_LOCAL void duk__emit_load_int32_noshuffle(duk_compiler_ctx *comp_ctx, duk_regconst_t reg, duk_int32_t val) { duk__emit_load_int32_raw(comp_ctx, reg, val, DUK__EMIT_FLAG_NO_SHUFFLE_A /*op_flags*/); } #else DUK_LOCAL void duk__emit_load_int32_noshuffle(duk_compiler_ctx *comp_ctx, duk_regconst_t reg, duk_int32_t val) { /* When torture not enabled, can just use the same helper because * 'reg' won't get spilled. */ DUK_ASSERT(reg <= DUK_BC_A_MAX); duk__emit_load_int32(comp_ctx, reg, val); } #endif DUK_LOCAL void duk__emit_jump(duk_compiler_ctx *comp_ctx, duk_int_t target_pc) { duk_int_t curr_pc; duk_int_t offset; curr_pc = (duk_int_t) (DUK_BW_GET_SIZE(comp_ctx->thr, &comp_ctx->curr_func.bw_code) / sizeof(duk_compiler_instr)); offset = (duk_int_t) target_pc - (duk_int_t) curr_pc - 1; DUK_ASSERT(offset + DUK_BC_JUMP_BIAS >= DUK_BC_ABC_MIN); DUK_ASSERT(offset + DUK_BC_JUMP_BIAS <= DUK_BC_ABC_MAX); duk__emit_abc(comp_ctx, DUK_OP_JUMP, (duk_regconst_t) (offset + DUK_BC_JUMP_BIAS)); } DUK_LOCAL duk_int_t duk__emit_jump_empty(duk_compiler_ctx *comp_ctx) { duk_int_t ret; ret = duk__get_current_pc(comp_ctx); /* useful for patching jumps later */ duk__emit_op_only(comp_ctx, DUK_OP_JUMP); return ret; } /* Insert an empty jump in the middle of code emitted earlier. This is * currently needed for compiling for-in. */ DUK_LOCAL void duk__insert_jump_entry(duk_compiler_ctx *comp_ctx, duk_int_t jump_pc) { #if defined(DUK_USE_PC2LINE) duk_int_t line; #endif duk_compiler_instr *instr; duk_size_t offset; DUK_ASSERT(jump_pc >= 0); offset = (duk_size_t) jump_pc * sizeof(duk_compiler_instr); instr = (duk_compiler_instr *) (void *) DUK_BW_INSERT_ENSURE_AREA(comp_ctx->thr, &comp_ctx->curr_func.bw_code, offset, sizeof(duk_compiler_instr)); #if defined(DUK_USE_PC2LINE) line = comp_ctx->curr_token.start_line; /* approximation, close enough */ #endif instr->ins = DUK_ENC_OP_ABC(DUK_OP_JUMP, 0); #if defined(DUK_USE_PC2LINE) instr->line = (duk_uint32_t) line; #endif DUK_BW_ADD_PTR(comp_ctx->thr, &comp_ctx->curr_func.bw_code, sizeof(duk_compiler_instr)); if (DUK_UNLIKELY(DUK_BW_GET_SIZE(comp_ctx->thr, &comp_ctx->curr_func.bw_code) > DUK_USE_ESBC_MAX_BYTES)) { goto fail_bc_limit; } return; fail_bc_limit: DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_BYTECODE_LIMIT); DUK_WO_NORETURN(return;); } /* Does not assume that jump_pc contains a DUK_OP_JUMP previously; this is intentional * to allow e.g. an INVALID opcode be overwritten with a JUMP (label management uses this). */ DUK_LOCAL void duk__patch_jump(duk_compiler_ctx *comp_ctx, duk_int_t jump_pc, duk_int_t target_pc) { duk_compiler_instr *instr; duk_int_t offset; /* allow negative PCs, behave as a no-op */ if (jump_pc < 0) { DUK_DDD(DUK_DDDPRINT("duk__patch_jump(): nop call, jump_pc=%ld (<0), target_pc=%ld", (long) jump_pc, (long) target_pc)); return; } DUK_ASSERT(jump_pc >= 0); /* XXX: range assert */ instr = duk__get_instr_ptr(comp_ctx, jump_pc); DUK_ASSERT(instr != NULL); /* XXX: range assert */ offset = target_pc - jump_pc - 1; instr->ins = DUK_ENC_OP_ABC(DUK_OP_JUMP, offset + DUK_BC_JUMP_BIAS); DUK_DDD(DUK_DDDPRINT("duk__patch_jump(): jump_pc=%ld, target_pc=%ld, offset=%ld", (long) jump_pc, (long) target_pc, (long) offset)); } DUK_LOCAL void duk__patch_jump_here(duk_compiler_ctx *comp_ctx, duk_int_t jump_pc) { duk__patch_jump(comp_ctx, jump_pc, duk__get_current_pc(comp_ctx)); } DUK_LOCAL void duk__patch_trycatch(duk_compiler_ctx *comp_ctx, duk_int_t ldconst_pc, duk_int_t trycatch_pc, duk_regconst_t reg_catch, duk_regconst_t const_varname, duk_small_uint_t flags) { duk_compiler_instr *instr; DUK_ASSERT(DUK__ISREG(reg_catch)); instr = duk__get_instr_ptr(comp_ctx, ldconst_pc); DUK_ASSERT(DUK_DEC_OP(instr->ins) == DUK_OP_LDCONST); DUK_ASSERT(instr != NULL); if (const_varname & DUK__CONST_MARKER) { /* Have a catch variable. */ const_varname = const_varname & (~DUK__CONST_MARKER); if (reg_catch > DUK_BC_BC_MAX || const_varname > DUK_BC_BC_MAX) { /* Catch attempts to use out-of-range reg/const. Without this * check Duktape 0.12.0 could generate invalid code which caused * an assert failure on execution. This error is triggered e.g. * for functions with a lot of constants and a try-catch statement. * Shuffling or opcode semantics change is needed to fix the issue. * See: test-bug-trycatch-many-constants.js. */ DUK_D(DUK_DPRINT("failed to patch trycatch: flags=%ld, reg_catch=%ld, const_varname=%ld (0x%08lx)", (long) flags, (long) reg_catch, (long) const_varname, (long) const_varname)); DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_REG_LIMIT); DUK_WO_NORETURN(return;); } instr->ins |= DUK_ENC_OP_A_BC(0, 0, const_varname); } else { /* No catch variable, e.g. a try-finally; replace LDCONST with * NOP to avoid a bogus LDCONST. */ instr->ins = DUK_ENC_OP(DUK_OP_NOP); } instr = duk__get_instr_ptr(comp_ctx, trycatch_pc); DUK_ASSERT(instr != NULL); DUK_ASSERT_DISABLE(flags >= DUK_BC_A_MIN); DUK_ASSERT(flags <= DUK_BC_A_MAX); instr->ins = DUK_ENC_OP_A_BC(DUK_OP_TRYCATCH, flags, reg_catch); } DUK_LOCAL void duk__emit_if_false_skip(duk_compiler_ctx *comp_ctx, duk_regconst_t regconst) { duk_small_uint_t op; op = DUK__ISREG(regconst) ? DUK_OP_IFFALSE_R : DUK_OP_IFFALSE_C; duk__emit_bc(comp_ctx, op, regconst); /* helper will remove const flag */ } DUK_LOCAL void duk__emit_if_true_skip(duk_compiler_ctx *comp_ctx, duk_regconst_t regconst) { duk_small_uint_t op; op = DUK__ISREG(regconst) ? DUK_OP_IFTRUE_R : DUK_OP_IFTRUE_C; duk__emit_bc(comp_ctx, op, regconst); /* helper will remove const flag */ } DUK_LOCAL void duk__emit_invalid(duk_compiler_ctx *comp_ctx) { duk__emit_op_only(comp_ctx, DUK_OP_INVALID); } /* * Peephole optimizer for finished bytecode. * * Does not remove opcodes; currently only straightens out unconditional * jump chains which are generated by several control structures. */ DUK_LOCAL void duk__peephole_optimize_bytecode(duk_compiler_ctx *comp_ctx) { duk_compiler_instr *bc; duk_small_uint_t iter; duk_int_t i, n; duk_int_t count_opt; bc = (duk_compiler_instr *) (void *) DUK_BW_GET_BASEPTR(comp_ctx->thr, &comp_ctx->curr_func.bw_code); #if defined(DUK_USE_BUFLEN16) /* No need to assert, buffer size maximum is 0xffff. */ #else DUK_ASSERT((duk_size_t) DUK_BW_GET_SIZE(comp_ctx->thr, &comp_ctx->curr_func.bw_code) / sizeof(duk_compiler_instr) <= (duk_size_t) DUK_INT_MAX); /* bytecode limits */ #endif n = (duk_int_t) (DUK_BW_GET_SIZE(comp_ctx->thr, &comp_ctx->curr_func.bw_code) / sizeof(duk_compiler_instr)); for (iter = 0; iter < DUK_COMPILER_PEEPHOLE_MAXITER; iter++) { count_opt = 0; for (i = 0; i < n; i++) { duk_instr_t ins; duk_int_t target_pc1; duk_int_t target_pc2; ins = bc[i].ins; if (DUK_DEC_OP(ins) != DUK_OP_JUMP) { continue; } target_pc1 = i + 1 + (duk_int_t) DUK_DEC_ABC(ins) - (duk_int_t) DUK_BC_JUMP_BIAS; DUK_DDD(DUK_DDDPRINT("consider jump at pc %ld; target_pc=%ld", (long) i, (long) target_pc1)); DUK_ASSERT(target_pc1 >= 0); DUK_ASSERT(target_pc1 < n); /* Note: if target_pc1 == i, we'll optimize a jump to itself. * This does not need to be checked for explicitly; the case * is rare and max iter breaks us out. */ ins = bc[target_pc1].ins; if (DUK_DEC_OP(ins) != DUK_OP_JUMP) { continue; } target_pc2 = target_pc1 + 1 + (duk_int_t) DUK_DEC_ABC(ins) - (duk_int_t) DUK_BC_JUMP_BIAS; DUK_DDD(DUK_DDDPRINT("optimizing jump at pc %ld; old target is %ld -> new target is %ld", (long) i, (long) target_pc1, (long) target_pc2)); bc[i].ins = DUK_ENC_OP_ABC(DUK_OP_JUMP, target_pc2 - (i + 1) + DUK_BC_JUMP_BIAS); count_opt++; } DUK_DD(DUK_DDPRINT("optimized %ld jumps on peephole round %ld", (long) count_opt, (long) (iter + 1))); if (count_opt == 0) { break; } } } /* * Intermediate value helpers */ /* Flags for intermediate value coercions. A flag for using a forced reg * is not needed, the forced_reg argument suffices and generates better * code (it is checked as it is used). */ /* XXX: DUK__IVAL_FLAG_REQUIRE_SHORT is passed but not currently implemented * by ispec/ivalue operations. */ #define DUK__IVAL_FLAG_ALLOW_CONST (1 << 0) /* allow a constant to be returned */ #define DUK__IVAL_FLAG_REQUIRE_TEMP (1 << 1) /* require a (mutable) temporary as a result (or a const if allowed) */ #define DUK__IVAL_FLAG_REQUIRE_SHORT (1 << 2) /* require a short (8-bit) reg/const which fits into bytecode B/C slot */ /* XXX: some code might benefit from DUK__SETTEMP_IFTEMP(thr,x) */ #if 0 /* enable manually for dumping */ #define DUK__DUMP_ISPEC(compctx,ispec) do { duk__dump_ispec((compctx), (ispec)); } while (0) #define DUK__DUMP_IVALUE(compctx,ivalue) do { duk__dump_ivalue((compctx), (ivalue)); } while (0) DUK_LOCAL void duk__dump_ispec(duk_compiler_ctx *comp_ctx, duk_ispec *x) { DUK_D(DUK_DPRINT("ispec dump: t=%ld regconst=0x%08lx, valstack_idx=%ld, value=%!T", (long) x->t, (unsigned long) x->regconst, (long) x->valstack_idx, duk_get_tval(comp_ctx->thr, x->valstack_idx))); } DUK_LOCAL void duk__dump_ivalue(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { DUK_D(DUK_DPRINT("ivalue dump: t=%ld op=%ld " "x1={t=%ld regconst=0x%08lx valstack_idx=%ld value=%!T} " "x2={t=%ld regconst=0x%08lx valstack_idx=%ld value=%!T}", (long) x->t, (long) x->op, (long) x->x1.t, (unsigned long) x->x1.regconst, (long) x->x1.valstack_idx, duk_get_tval(comp_ctx->thr, x->x1.valstack_idx), (long) x->x2.t, (unsigned long) x->x2.regconst, (long) x->x2.valstack_idx, duk_get_tval(comp_ctx->thr, x->x2.valstack_idx))); } #else #define DUK__DUMP_ISPEC(comp_ctx,x) do {} while (0) #define DUK__DUMP_IVALUE(comp_ctx,x) do {} while (0) #endif DUK_LOCAL void duk__ivalue_regconst(duk_ivalue *x, duk_regconst_t regconst) { x->t = DUK_IVAL_PLAIN; x->x1.t = DUK_ISPEC_REGCONST; x->x1.regconst = regconst; } DUK_LOCAL void duk__ivalue_plain_fromstack(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { x->t = DUK_IVAL_PLAIN; x->x1.t = DUK_ISPEC_VALUE; duk_replace(comp_ctx->thr, x->x1.valstack_idx); } DUK_LOCAL void duk__ivalue_var_fromstack(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { x->t = DUK_IVAL_VAR; x->x1.t = DUK_ISPEC_VALUE; duk_replace(comp_ctx->thr, x->x1.valstack_idx); } DUK_LOCAL_DECL void duk__ivalue_var_hstring(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_hstring *h) { DUK_ASSERT(h != NULL); duk_push_hstring(comp_ctx->thr, h); duk__ivalue_var_fromstack(comp_ctx, x); } DUK_LOCAL void duk__copy_ispec(duk_compiler_ctx *comp_ctx, duk_ispec *src, duk_ispec *dst) { dst->t = src->t; dst->regconst = src->regconst; duk_copy(comp_ctx->thr, src->valstack_idx, dst->valstack_idx); } DUK_LOCAL void duk__copy_ivalue(duk_compiler_ctx *comp_ctx, duk_ivalue *src, duk_ivalue *dst) { dst->t = src->t; dst->op = src->op; dst->x1.t = src->x1.t; dst->x1.regconst = src->x1.regconst; dst->x2.t = src->x2.t; dst->x2.regconst = src->x2.regconst; duk_copy(comp_ctx->thr, src->x1.valstack_idx, dst->x1.valstack_idx); duk_copy(comp_ctx->thr, src->x2.valstack_idx, dst->x2.valstack_idx); } DUK_LOCAL duk_regconst_t duk__alloctemps(duk_compiler_ctx *comp_ctx, duk_small_int_t num) { duk_regconst_t res; res = comp_ctx->curr_func.temp_next; comp_ctx->curr_func.temp_next += num; if (comp_ctx->curr_func.temp_next > DUK__MAX_TEMPS) { /* == DUK__MAX_TEMPS is OK */ DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_TEMP_LIMIT); DUK_WO_NORETURN(return 0;); } /* maintain highest 'used' temporary, needed to figure out nregs of function */ if (comp_ctx->curr_func.temp_next > comp_ctx->curr_func.temp_max) { comp_ctx->curr_func.temp_max = comp_ctx->curr_func.temp_next; } return res; } DUK_LOCAL duk_regconst_t duk__alloctemp(duk_compiler_ctx *comp_ctx) { return duk__alloctemps(comp_ctx, 1); } DUK_LOCAL void duk__settemp_checkmax(duk_compiler_ctx *comp_ctx, duk_regconst_t temp_next) { comp_ctx->curr_func.temp_next = temp_next; if (temp_next > comp_ctx->curr_func.temp_max) { comp_ctx->curr_func.temp_max = temp_next; } } /* get const for value at valstack top */ DUK_LOCAL duk_regconst_t duk__getconst(duk_compiler_ctx *comp_ctx) { duk_hthread *thr = comp_ctx->thr; duk_compiler_func *f = &comp_ctx->curr_func; duk_tval *tv1; duk_int_t i, n, n_check; n = (duk_int_t) duk_get_length(thr, f->consts_idx); tv1 = DUK_GET_TVAL_NEGIDX(thr, -1); DUK_ASSERT(tv1 != NULL); #if defined(DUK_USE_FASTINT) /* Explicit check for fastint downgrade. */ DUK_TVAL_CHKFAST_INPLACE_SLOW(tv1); #endif /* Sanity workaround for handling functions with a large number of * constants at least somewhat reasonably. Otherwise checking whether * we already have the constant would grow very slow (as it is O(N^2)). */ n_check = (n > DUK__GETCONST_MAX_CONSTS_CHECK ? DUK__GETCONST_MAX_CONSTS_CHECK : n); for (i = 0; i < n_check; i++) { duk_tval *tv2 = DUK_HOBJECT_A_GET_VALUE_PTR(thr->heap, f->h_consts, i); /* Strict equality is NOT enough, because we cannot use the same * constant for e.g. +0 and -0. */ if (duk_js_samevalue(tv1, tv2)) { DUK_DDD(DUK_DDDPRINT("reused existing constant for %!T -> const index %ld", (duk_tval *) tv1, (long) i)); duk_pop(thr); return (duk_regconst_t) i | (duk_regconst_t) DUK__CONST_MARKER; } } if (n > DUK__MAX_CONSTS) { DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_CONST_LIMIT); DUK_WO_NORETURN(return 0;); } DUK_DDD(DUK_DDDPRINT("allocating new constant for %!T -> const index %ld", (duk_tval *) tv1, (long) n)); (void) duk_put_prop_index(thr, f->consts_idx, (duk_uarridx_t) n); /* invalidates tv1, tv2 */ return (duk_regconst_t) n | (duk_regconst_t) DUK__CONST_MARKER; } DUK_LOCAL duk_bool_t duk__const_needs_refcount(duk_compiler_ctx *comp_ctx, duk_regconst_t rc) { #if defined(DUK_USE_REFERENCE_COUNTING) duk_compiler_func *f = &comp_ctx->curr_func; duk_bool_t ret; DUK_ASSERT((rc & DUK__CONST_MARKER) == 0); /* caller removes const marker */ (void) duk_get_prop_index(comp_ctx->thr, f->consts_idx, (duk_uarridx_t) rc); ret = !duk_is_number(comp_ctx->thr, -1); /* now only number/string, so conservative check */ duk_pop(comp_ctx->thr); return ret; #else DUK_UNREF(comp_ctx); DUK_UNREF(rc); DUK_ASSERT((rc & DUK__CONST_MARKER) == 0); /* caller removes const marker */ return 0; #endif } /* Get the value represented by an duk_ispec to a register or constant. * The caller can control the result by indicating whether or not: * * (1) a constant is allowed (sometimes the caller needs the result to * be in a register) * * (2) a temporary register is required (usually when caller requires * the register to be safely mutable; normally either a bound * register or a temporary register are both OK) * * (3) a forced register target needs to be used * * Bytecode may be emitted to generate the necessary value. The return * value is either a register or a constant. */ DUK_LOCAL duk_regconst_t duk__ispec_toregconst_raw(duk_compiler_ctx *comp_ctx, duk_ispec *x, duk_regconst_t forced_reg, duk_small_uint_t flags) { duk_hthread *thr = comp_ctx->thr; DUK_DDD(DUK_DDDPRINT("duk__ispec_toregconst_raw(): x={%ld:%ld:%!T}, " "forced_reg=%ld, flags 0x%08lx: allow_const=%ld require_temp=%ld require_short=%ld", (long) x->t, (long) x->regconst, (duk_tval *) duk_get_tval(thr, x->valstack_idx), (long) forced_reg, (unsigned long) flags, (long) ((flags & DUK__IVAL_FLAG_ALLOW_CONST) ? 1 : 0), (long) ((flags & DUK__IVAL_FLAG_REQUIRE_TEMP) ? 1 : 0), (long) ((flags & DUK__IVAL_FLAG_REQUIRE_SHORT) ? 1 : 0))); switch (x->t) { case DUK_ISPEC_VALUE: { duk_tval *tv; tv = DUK_GET_TVAL_POSIDX(thr, x->valstack_idx); DUK_ASSERT(tv != NULL); switch (DUK_TVAL_GET_TAG(tv)) { case DUK_TAG_UNDEFINED: { /* Note: although there is no 'undefined' literal, undefined * values can occur during compilation as a result of e.g. * the 'void' operator. */ duk_regconst_t dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_bc(comp_ctx, DUK_OP_LDUNDEF, dest); return dest; } case DUK_TAG_NULL: { duk_regconst_t dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_bc(comp_ctx, DUK_OP_LDNULL, dest); return dest; } case DUK_TAG_BOOLEAN: { duk_regconst_t dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_bc(comp_ctx, (DUK_TVAL_GET_BOOLEAN(tv) ? DUK_OP_LDTRUE : DUK_OP_LDFALSE), dest); return dest; } case DUK_TAG_POINTER: { DUK_UNREACHABLE(); break; } case DUK_TAG_STRING: { duk_hstring *h; duk_regconst_t dest; duk_regconst_t constidx; h = DUK_TVAL_GET_STRING(tv); DUK_UNREF(h); DUK_ASSERT(h != NULL); #if 0 /* XXX: to be implemented? */ /* Use special opcodes to load short strings */ if (DUK_HSTRING_GET_BYTELEN(h) <= 2) { /* Encode into a single opcode (18 bits can encode 1-2 bytes + length indicator) */ } else if (DUK_HSTRING_GET_BYTELEN(h) <= 6) { /* Encode into a double constant (53 bits can encode 6*8 = 48 bits + 3-bit length */ } #endif duk_dup(thr, x->valstack_idx); constidx = duk__getconst(comp_ctx); if (flags & DUK__IVAL_FLAG_ALLOW_CONST) { return constidx; } dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_a_bc(comp_ctx, DUK_OP_LDCONST, dest, constidx); return dest; } case DUK_TAG_OBJECT: { DUK_UNREACHABLE(); break; } case DUK_TAG_BUFFER: { DUK_UNREACHABLE(); break; } case DUK_TAG_LIGHTFUNC: { DUK_UNREACHABLE(); break; } #if defined(DUK_USE_FASTINT) case DUK_TAG_FASTINT: #endif default: { /* number */ duk_regconst_t dest; duk_regconst_t constidx; duk_double_t dval; duk_int32_t ival; DUK_ASSERT(!DUK_TVAL_IS_UNUSED(tv)); DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv)); dval = DUK_TVAL_GET_NUMBER(tv); if (!(flags & DUK__IVAL_FLAG_ALLOW_CONST)) { /* A number can be loaded either through a constant, using * LDINT, or using LDINT+LDINTX. LDINT is always a size win, * LDINT+LDINTX is not if the constant is used multiple times. * Currently always prefer LDINT+LDINTX over a double constant. */ if (duk_is_whole_get_int32_nonegzero(dval, &ival)) { dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_load_int32(comp_ctx, dest, ival); return dest; } } duk_dup(thr, x->valstack_idx); constidx = duk__getconst(comp_ctx); if (flags & DUK__IVAL_FLAG_ALLOW_CONST) { return constidx; } else { dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_a_bc(comp_ctx, DUK_OP_LDCONST, dest, constidx); return dest; } } } /* end switch */ goto fail_internal; /* never here */ } case DUK_ISPEC_REGCONST: { if (forced_reg >= 0) { if (DUK__ISCONST(x->regconst)) { duk__emit_a_bc(comp_ctx, DUK_OP_LDCONST, forced_reg, x->regconst); } else if (x->regconst != forced_reg) { duk__emit_a_bc(comp_ctx, DUK_OP_LDREG, forced_reg, x->regconst); } else { ; /* already in correct reg */ } return forced_reg; } DUK_ASSERT(forced_reg < 0); if (DUK__ISCONST(x->regconst)) { if (!(flags & DUK__IVAL_FLAG_ALLOW_CONST)) { duk_regconst_t dest = DUK__ALLOCTEMP(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_LDCONST, dest, x->regconst); return dest; } return x->regconst; } DUK_ASSERT(forced_reg < 0 && !DUK__ISCONST(x->regconst)); if ((flags & DUK__IVAL_FLAG_REQUIRE_TEMP) && !DUK__ISREG_TEMP(comp_ctx, x->regconst)) { duk_regconst_t dest = DUK__ALLOCTEMP(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_LDREG, dest, x->regconst); return dest; } return x->regconst; } default: { break; /* never here */ } } fail_internal: DUK_ERROR_INTERNAL(thr); DUK_WO_NORETURN(return 0;); } DUK_LOCAL void duk__ispec_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ispec *x, duk_regconst_t forced_reg) { DUK_ASSERT(forced_reg >= 0); (void) duk__ispec_toregconst_raw(comp_ctx, x, forced_reg, 0 /*flags*/); } /* Coerce an duk_ivalue to a 'plain' value by generating the necessary * arithmetic operations, property access, or variable access bytecode. * The duk_ivalue argument ('x') is converted into a plain value as a * side effect. */ DUK_LOCAL void duk__ivalue_toplain_raw(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_regconst_t forced_reg) { duk_hthread *thr = comp_ctx->thr; DUK_DDD(DUK_DDDPRINT("duk__ivalue_toplain_raw(): x={t=%ld,op=%ld,x1={%ld:%ld:%!T},x2={%ld:%ld:%!T}}, " "forced_reg=%ld", (long) x->t, (long) x->op, (long) x->x1.t, (long) x->x1.regconst, (duk_tval *) duk_get_tval(thr, x->x1.valstack_idx), (long) x->x2.t, (long) x->x2.regconst, (duk_tval *) duk_get_tval(thr, x->x2.valstack_idx), (long) forced_reg)); switch (x->t) { case DUK_IVAL_PLAIN: { return; } /* XXX: support unary arithmetic ivalues (useful?) */ case DUK_IVAL_ARITH: { duk_regconst_t arg1; duk_regconst_t arg2; duk_regconst_t dest; duk_tval *tv1; duk_tval *tv2; DUK_DDD(DUK_DDDPRINT("arith to plain conversion")); /* inline arithmetic check for constant values */ /* XXX: use the exactly same arithmetic function here as in executor */ if (x->x1.t == DUK_ISPEC_VALUE && x->x2.t == DUK_ISPEC_VALUE && x->t == DUK_IVAL_ARITH) { tv1 = DUK_GET_TVAL_POSIDX(thr, x->x1.valstack_idx); tv2 = DUK_GET_TVAL_POSIDX(thr, x->x2.valstack_idx); DUK_ASSERT(tv1 != NULL); DUK_ASSERT(tv2 != NULL); DUK_DDD(DUK_DDDPRINT("arith: tv1=%!T, tv2=%!T", (duk_tval *) tv1, (duk_tval *) tv2)); if (DUK_TVAL_IS_NUMBER(tv1) && DUK_TVAL_IS_NUMBER(tv2)) { duk_double_t d1 = DUK_TVAL_GET_NUMBER(tv1); duk_double_t d2 = DUK_TVAL_GET_NUMBER(tv2); duk_double_t d3; duk_bool_t accept_fold = 1; DUK_DDD(DUK_DDDPRINT("arith inline check: d1=%lf, d2=%lf, op=%ld", (double) d1, (double) d2, (long) x->op)); switch (x->op) { case DUK_OP_ADD: { d3 = d1 + d2; break; } case DUK_OP_SUB: { d3 = d1 - d2; break; } case DUK_OP_MUL: { d3 = d1 * d2; break; } case DUK_OP_DIV: { /* Division-by-zero is undefined * behavior, so rely on a helper. */ d3 = duk_double_div(d1, d2); break; } case DUK_OP_EXP: { d3 = (duk_double_t) duk_js_arith_pow((double) d1, (double) d2); break; } default: { d3 = 0.0; /* Won't be used, but silence MSVC /W4 warning. */ accept_fold = 0; break; } } if (accept_fold) { duk_double_union du; du.d = d3; DUK_DBLUNION_NORMALIZE_NAN_CHECK(&du); d3 = du.d; x->t = DUK_IVAL_PLAIN; DUK_ASSERT(x->x1.t == DUK_ISPEC_VALUE); DUK_TVAL_SET_NUMBER(tv1, d3); /* old value is number: no refcount */ return; } } else if (x->op == DUK_OP_ADD && DUK_TVAL_IS_STRING(tv1) && DUK_TVAL_IS_STRING(tv2)) { /* Inline string concatenation. No need to check for * symbols, as all inputs are valid ECMAScript strings. */ duk_dup(thr, x->x1.valstack_idx); duk_dup(thr, x->x2.valstack_idx); duk_concat(thr, 2); duk_replace(thr, x->x1.valstack_idx); x->t = DUK_IVAL_PLAIN; DUK_ASSERT(x->x1.t == DUK_ISPEC_VALUE); return; } } arg1 = duk__ispec_toregconst_raw(comp_ctx, &x->x1, -1, DUK__IVAL_FLAG_ALLOW_CONST | DUK__IVAL_FLAG_REQUIRE_SHORT /*flags*/); arg2 = duk__ispec_toregconst_raw(comp_ctx, &x->x2, -1, DUK__IVAL_FLAG_ALLOW_CONST | DUK__IVAL_FLAG_REQUIRE_SHORT /*flags*/); /* If forced reg, use it as destination. Otherwise try to * use either coerced ispec if it is a temporary. */ if (forced_reg >= 0) { dest = forced_reg; } else if (DUK__ISREG_TEMP(comp_ctx, arg1)) { dest = arg1; } else if (DUK__ISREG_TEMP(comp_ctx, arg2)) { dest = arg2; } else { dest = DUK__ALLOCTEMP(comp_ctx); } DUK_ASSERT(DUK__ISREG(dest)); duk__emit_a_b_c(comp_ctx, x->op | DUK__EMIT_FLAG_BC_REGCONST, dest, arg1, arg2); duk__ivalue_regconst(x, dest); return; } case DUK_IVAL_PROP: { /* XXX: very similar to DUK_IVAL_ARITH - merge? */ duk_regconst_t arg1; duk_regconst_t arg2; duk_regconst_t dest; /* Need a short reg/const, does not have to be a mutable temp. */ arg1 = duk__ispec_toregconst_raw(comp_ctx, &x->x1, -1, DUK__IVAL_FLAG_ALLOW_CONST | DUK__IVAL_FLAG_REQUIRE_SHORT /*flags*/); arg2 = duk__ispec_toregconst_raw(comp_ctx, &x->x2, -1, DUK__IVAL_FLAG_ALLOW_CONST | DUK__IVAL_FLAG_REQUIRE_SHORT /*flags*/); /* Pick a destination register. If either base value or key * happens to be a temp value, reuse it as the destination. * * XXX: The temp must be a "mutable" one, i.e. such that no * other expression is using it anymore. Here this should be * the case because the value of a property access expression * is neither the base nor the key, but the lookup result. */ if (forced_reg >= 0) { dest = forced_reg; } else if (DUK__ISREG_TEMP(comp_ctx, arg1)) { dest = arg1; } else if (DUK__ISREG_TEMP(comp_ctx, arg2)) { dest = arg2; } else { dest = DUK__ALLOCTEMP(comp_ctx); } duk__emit_a_b_c(comp_ctx, DUK_OP_GETPROP | DUK__EMIT_FLAG_BC_REGCONST, dest, arg1, arg2); duk__ivalue_regconst(x, dest); return; } case DUK_IVAL_VAR: { /* x1 must be a string */ duk_regconst_t dest; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; DUK_ASSERT(x->x1.t == DUK_ISPEC_VALUE); duk_dup(thr, x->x1.valstack_idx); if (duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { duk__ivalue_regconst(x, reg_varbind); } else { dest = (forced_reg >= 0 ? forced_reg : DUK__ALLOCTEMP(comp_ctx)); duk__emit_a_bc(comp_ctx, DUK_OP_GETVAR, dest, rc_varname); duk__ivalue_regconst(x, dest); } return; } case DUK_IVAL_NONE: default: { DUK_D(DUK_DPRINT("invalid ivalue type: %ld", (long) x->t)); break; } } DUK_ERROR_INTERNAL(thr); DUK_WO_NORETURN(return;); } /* evaluate to plain value, no forced register (temp/bound reg both ok) */ DUK_LOCAL void duk__ivalue_toplain(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { duk__ivalue_toplain_raw(comp_ctx, x, -1 /*forced_reg*/); } /* evaluate to final form (e.g. coerce GETPROP to code), throw away temp */ DUK_LOCAL void duk__ivalue_toplain_ignore(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { duk_regconst_t temp; /* If duk__ivalue_toplain_raw() allocates a temp, forget it and * restore next temp state. */ temp = DUK__GETTEMP(comp_ctx); duk__ivalue_toplain_raw(comp_ctx, x, -1 /*forced_reg*/); DUK__SETTEMP(comp_ctx, temp); } /* Coerce an duk_ivalue to a register or constant; result register may * be a temp or a bound register. * * The duk_ivalue argument ('x') is converted into a regconst as a * side effect. */ DUK_LOCAL duk_regconst_t duk__ivalue_toregconst_raw(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_regconst_t forced_reg, duk_small_uint_t flags) { duk_hthread *thr = comp_ctx->thr; duk_regconst_t reg; DUK_UNREF(thr); DUK_DDD(DUK_DDDPRINT("duk__ivalue_toregconst_raw(): x={t=%ld,op=%ld,x1={%ld:%ld:%!T},x2={%ld:%ld:%!T}}, " "forced_reg=%ld, flags 0x%08lx: allow_const=%ld require_temp=%ld require_short=%ld", (long) x->t, (long) x->op, (long) x->x1.t, (long) x->x1.regconst, (duk_tval *) duk_get_tval(thr, x->x1.valstack_idx), (long) x->x2.t, (long) x->x2.regconst, (duk_tval *) duk_get_tval(thr, x->x2.valstack_idx), (long) forced_reg, (unsigned long) flags, (long) ((flags & DUK__IVAL_FLAG_ALLOW_CONST) ? 1 : 0), (long) ((flags & DUK__IVAL_FLAG_REQUIRE_TEMP) ? 1 : 0), (long) ((flags & DUK__IVAL_FLAG_REQUIRE_SHORT) ? 1 : 0))); /* first coerce to a plain value */ duk__ivalue_toplain_raw(comp_ctx, x, forced_reg); DUK_ASSERT(x->t == DUK_IVAL_PLAIN); /* then to a register */ reg = duk__ispec_toregconst_raw(comp_ctx, &x->x1, forced_reg, flags); duk__ivalue_regconst(x, reg); return reg; } DUK_LOCAL duk_regconst_t duk__ivalue_toreg(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { return duk__ivalue_toregconst_raw(comp_ctx, x, -1, 0 /*flags*/); } #if 0 /* unused */ DUK_LOCAL duk_regconst_t duk__ivalue_totemp(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { return duk__ivalue_toregconst_raw(comp_ctx, x, -1, DUK__IVAL_FLAG_REQUIRE_TEMP /*flags*/); } #endif DUK_LOCAL void duk__ivalue_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ivalue *x, duk_int_t forced_reg) { DUK_ASSERT(forced_reg >= 0); (void) duk__ivalue_toregconst_raw(comp_ctx, x, forced_reg, 0 /*flags*/); } DUK_LOCAL duk_regconst_t duk__ivalue_toregconst(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { return duk__ivalue_toregconst_raw(comp_ctx, x, -1, DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); } DUK_LOCAL duk_regconst_t duk__ivalue_totempconst(duk_compiler_ctx *comp_ctx, duk_ivalue *x) { return duk__ivalue_toregconst_raw(comp_ctx, x, -1, DUK__IVAL_FLAG_ALLOW_CONST | DUK__IVAL_FLAG_REQUIRE_TEMP /*flags*/); } /* The issues below can be solved with better flags */ /* XXX: many operations actually want toforcedtemp() -- brand new temp? */ /* XXX: need a toplain_ignore() which will only coerce a value to a temp * register if it might have a side effect. Side-effect free values do not * need to be coerced. */ /* * Identifier handling */ DUK_LOCAL duk_regconst_t duk__lookup_active_register_binding(duk_compiler_ctx *comp_ctx) { duk_hthread *thr = comp_ctx->thr; duk_hstring *h_varname; duk_regconst_t ret; DUK_DDD(DUK_DDDPRINT("resolving identifier reference to '%!T'", (duk_tval *) duk_get_tval(thr, -1))); /* * Special name handling */ h_varname = duk_known_hstring(thr, -1); if (h_varname == DUK_HTHREAD_STRING_LC_ARGUMENTS(thr)) { DUK_DDD(DUK_DDDPRINT("flagging function as accessing 'arguments'")); comp_ctx->curr_func.id_access_arguments = 1; } /* * Inside one or more 'with' statements fall back to slow path always. * (See e.g. test-stmt-with.js.) */ if (comp_ctx->curr_func.with_depth > 0) { DUK_DDD(DUK_DDDPRINT("identifier lookup inside a 'with' -> fall back to slow path")); goto slow_path_own; } /* * Any catch bindings ("catch (e)") also affect identifier binding. * * Currently, the varmap is modified for the duration of the catch * clause to ensure any identifier accesses with the catch variable * name will use slow path. */ duk_get_prop(thr, comp_ctx->curr_func.varmap_idx); if (duk_is_number(thr, -1)) { ret = duk_to_int(thr, -1); duk_pop(thr); } else { duk_pop(thr); if (comp_ctx->curr_func.catch_depth > 0 || comp_ctx->curr_func.with_depth > 0) { DUK_DDD(DUK_DDDPRINT("slow path access from inside a try-catch or with needs _Varmap")); goto slow_path_own; } else { /* In this case we're doing a variable lookup that doesn't * match our own variables, so _Varmap won't be needed at * run time. */ DUK_DDD(DUK_DDDPRINT("slow path access outside of try-catch and with, no need for _Varmap")); goto slow_path_notown; } } DUK_DDD(DUK_DDDPRINT("identifier lookup -> reg %ld", (long) ret)); return ret; slow_path_notown: DUK_DDD(DUK_DDDPRINT("identifier lookup -> slow path, not own variable")); comp_ctx->curr_func.id_access_slow = 1; return (duk_regconst_t) -1; slow_path_own: DUK_DDD(DUK_DDDPRINT("identifier lookup -> slow path, may be own variable")); comp_ctx->curr_func.id_access_slow = 1; comp_ctx->curr_func.id_access_slow_own = 1; return (duk_regconst_t) -1; } /* Lookup an identifier name in the current varmap, indicating whether the * identifier is register-bound and if not, allocating a constant for the * identifier name. Returns 1 if register-bound, 0 otherwise. Caller can * also check (out_reg_varbind >= 0) to check whether or not identifier is * register bound. The caller must NOT use out_rc_varname at all unless * return code is 0 or out_reg_varbind is < 0; this is becuase out_rc_varname * is unsigned and doesn't have a "unused" / none value. */ DUK_LOCAL duk_bool_t duk__lookup_lhs(duk_compiler_ctx *comp_ctx, duk_regconst_t *out_reg_varbind, duk_regconst_t *out_rc_varname) { duk_hthread *thr = comp_ctx->thr; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; /* [ ... varname ] */ duk_dup_top(thr); reg_varbind = duk__lookup_active_register_binding(comp_ctx); if (reg_varbind >= 0) { *out_reg_varbind = reg_varbind; *out_rc_varname = 0; /* duk_regconst_t is unsigned, so use 0 as dummy value (ignored by caller) */ duk_pop(thr); return 1; } else { rc_varname = duk__getconst(comp_ctx); *out_reg_varbind = -1; *out_rc_varname = rc_varname; return 0; } } /* * Label handling * * Labels are initially added with flags prohibiting both break and continue. * When the statement type is finally uncovered (after potentially multiple * labels), all the labels are updated to allow/prohibit break and continue. */ DUK_LOCAL void duk__add_label(duk_compiler_ctx *comp_ctx, duk_hstring *h_label, duk_int_t pc_label, duk_int_t label_id) { duk_hthread *thr = comp_ctx->thr; duk_size_t n; duk_size_t new_size; duk_uint8_t *p; duk_labelinfo *li_start, *li; /* Duplicate (shadowing) labels are not allowed, except for the empty * labels (which are used as default labels for switch and iteration * statements). * * We could also allow shadowing of non-empty pending labels without any * other issues than breaking the required label shadowing requirements * of the E5 specification, see Section 12.12. */ p = (duk_uint8_t *) DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(thr->heap, comp_ctx->curr_func.h_labelinfos); li_start = (duk_labelinfo *) (void *) p; li = (duk_labelinfo *) (void *) (p + DUK_HBUFFER_GET_SIZE(comp_ctx->curr_func.h_labelinfos)); n = (duk_size_t) (li - li_start); while (li > li_start) { li--; if (li->h_label == h_label && h_label != DUK_HTHREAD_STRING_EMPTY_STRING(thr)) { DUK_ERROR_SYNTAX(thr, DUK_STR_DUPLICATE_LABEL); DUK_WO_NORETURN(return;); } } duk_push_hstring(thr, h_label); DUK_ASSERT(n <= DUK_UARRIDX_MAX); /* label limits */ (void) duk_put_prop_index(thr, comp_ctx->curr_func.labelnames_idx, (duk_uarridx_t) n); new_size = (n + 1) * sizeof(duk_labelinfo); duk_hbuffer_resize(thr, comp_ctx->curr_func.h_labelinfos, new_size); /* XXX: slack handling, slow now */ /* relookup after possible realloc */ p = (duk_uint8_t *) DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(thr->heap, comp_ctx->curr_func.h_labelinfos); li_start = (duk_labelinfo *) (void *) p; DUK_UNREF(li_start); /* silence scan-build warning */ li = (duk_labelinfo *) (void *) (p + DUK_HBUFFER_GET_SIZE(comp_ctx->curr_func.h_labelinfos)); li--; /* Labels can be used for iteration statements but also for other statements, * in particular a label can be used for a block statement. All cases of a * named label accept a 'break' so that flag is set here. Iteration statements * also allow 'continue', so that flag is updated when we figure out the * statement type. */ li->flags = DUK_LABEL_FLAG_ALLOW_BREAK; li->label_id = label_id; li->h_label = h_label; li->catch_depth = comp_ctx->curr_func.catch_depth; /* catch depth from current func */ li->pc_label = pc_label; DUK_DDD(DUK_DDDPRINT("registered label: flags=0x%08lx, id=%ld, name=%!O, catch_depth=%ld, pc_label=%ld", (unsigned long) li->flags, (long) li->label_id, (duk_heaphdr *) li->h_label, (long) li->catch_depth, (long) li->pc_label)); } /* Update all labels with matching label_id. */ DUK_LOCAL void duk__update_label_flags(duk_compiler_ctx *comp_ctx, duk_int_t label_id, duk_small_uint_t flags) { duk_uint8_t *p; duk_labelinfo *li_start, *li; p = (duk_uint8_t *) DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(comp_ctx->thr->heap, comp_ctx->curr_func.h_labelinfos); li_start = (duk_labelinfo *) (void *) p; li = (duk_labelinfo *) (void *) (p + DUK_HBUFFER_GET_SIZE(comp_ctx->curr_func.h_labelinfos)); /* Match labels starting from latest; once label_id no longer matches, we can * safely exit without checking the rest of the labels (only the topmost labels * are ever updated). */ while (li > li_start) { li--; if (li->label_id != label_id) { break; } DUK_DDD(DUK_DDDPRINT("updating (overwriting) label flags for li=%p, label_id=%ld, flags=%ld", (void *) li, (long) label_id, (long) flags)); li->flags = flags; } } /* Lookup active label information. Break/continue distinction is necessary to handle switch * statement related labels correctly: a switch will only catch a 'break', not a 'continue'. * * An explicit label cannot appear multiple times in the active set, but empty labels (unlabelled * iteration and switch statements) can. A break will match the closest unlabelled or labelled * statement. A continue will match the closest unlabelled or labelled iteration statement. It is * a syntax error if a continue matches a labelled switch statement; because an explicit label cannot * be duplicated, the continue cannot match any valid label outside the switch. * * A side effect of these rules is that a LABEL statement related to a switch should never actually * catch a continue abrupt completion at run-time. Hence an INVALID opcode can be placed in the * continue slot of the switch's LABEL statement. */ /* XXX: awkward, especially the bunch of separate output values -> output struct? */ DUK_LOCAL void duk__lookup_active_label(duk_compiler_ctx *comp_ctx, duk_hstring *h_label, duk_bool_t is_break, duk_int_t *out_label_id, duk_int_t *out_label_catch_depth, duk_int_t *out_label_pc, duk_bool_t *out_is_closest) { duk_hthread *thr = comp_ctx->thr; duk_uint8_t *p; duk_labelinfo *li_start, *li_end, *li; duk_bool_t match = 0; DUK_DDD(DUK_DDDPRINT("looking up active label: label='%!O', is_break=%ld", (duk_heaphdr *) h_label, (long) is_break)); DUK_UNREF(thr); p = (duk_uint8_t *) DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(thr->heap, comp_ctx->curr_func.h_labelinfos); li_start = (duk_labelinfo *) (void *) p; li_end = (duk_labelinfo *) (void *) (p + DUK_HBUFFER_GET_SIZE(comp_ctx->curr_func.h_labelinfos)); li = li_end; /* Match labels starting from latest label because there can be duplicate empty * labels in the label set. */ while (li > li_start) { li--; if (li->h_label != h_label) { DUK_DDD(DUK_DDDPRINT("labelinfo[%ld] ->'%!O' != %!O", (long) (li - li_start), (duk_heaphdr *) li->h_label, (duk_heaphdr *) h_label)); continue; } DUK_DDD(DUK_DDDPRINT("labelinfo[%ld] -> '%!O' label name matches (still need to check type)", (long) (li - li_start), (duk_heaphdr *) h_label)); /* currently all labels accept a break, so no explicit check for it now */ DUK_ASSERT(li->flags & DUK_LABEL_FLAG_ALLOW_BREAK); if (is_break) { /* break matches always */ match = 1; break; } else if (li->flags & DUK_LABEL_FLAG_ALLOW_CONTINUE) { /* iteration statements allow continue */ match = 1; break; } else { /* continue matched this label -- we can only continue if this is the empty * label, for which duplication is allowed, and thus there is hope of * finding a match deeper in the label stack. */ if (h_label != DUK_HTHREAD_STRING_EMPTY_STRING(thr)) { DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_LABEL); DUK_WO_NORETURN(return;); } else { DUK_DDD(DUK_DDDPRINT("continue matched an empty label which does not " "allow a continue -> continue lookup deeper in label stack")); } } } /* XXX: match flag is awkward, rework */ if (!match) { DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_LABEL); DUK_WO_NORETURN(return;); } DUK_DDD(DUK_DDDPRINT("label match: %!O -> label_id %ld, catch_depth=%ld, pc_label=%ld", (duk_heaphdr *) h_label, (long) li->label_id, (long) li->catch_depth, (long) li->pc_label)); *out_label_id = li->label_id; *out_label_catch_depth = li->catch_depth; *out_label_pc = li->pc_label; *out_is_closest = (li == li_end - 1); } DUK_LOCAL void duk__reset_labels_to_length(duk_compiler_ctx *comp_ctx, duk_size_t len) { duk_hthread *thr = comp_ctx->thr; duk_set_length(thr, comp_ctx->curr_func.labelnames_idx, len); duk_hbuffer_resize(thr, comp_ctx->curr_func.h_labelinfos, sizeof(duk_labelinfo) * len); } /* * Expression parsing: duk__expr_nud(), duk__expr_led(), duk__expr_lbp(), and helpers. * * - duk__expr_nud(): ("null denotation"): process prev_token as a "start" of an expression (e.g. literal) * - duk__expr_led(): ("left denotation"): process prev_token in the "middle" of an expression (e.g. operator) * - duk__expr_lbp(): ("left-binding power"): return left-binding power of curr_token */ /* object literal key tracking flags */ #define DUK__OBJ_LIT_KEY_PLAIN (1 << 0) /* key encountered as a plain property */ #define DUK__OBJ_LIT_KEY_GET (1 << 1) /* key encountered as a getter */ #define DUK__OBJ_LIT_KEY_SET (1 << 2) /* key encountered as a setter */ DUK_LOCAL void duk__nud_array_literal(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk_regconst_t reg_obj; /* result reg */ duk_regconst_t reg_temp; /* temp reg */ duk_regconst_t temp_start; /* temp reg value for start of loop */ duk_small_uint_t max_init_values; /* max # of values initialized in one MPUTARR set */ duk_small_uint_t num_values; /* number of values in current MPUTARR set */ duk_uarridx_t curr_idx; /* current (next) array index */ duk_uarridx_t start_idx; /* start array index of current MPUTARR set */ duk_uarridx_t init_idx; /* last array index explicitly initialized, +1 */ duk_bool_t require_comma; /* next loop requires a comma */ #if !defined(DUK_USE_PREFER_SIZE) duk_int_t pc_newarr; duk_compiler_instr *instr; #endif /* DUK_TOK_LBRACKET already eaten, current token is right after that */ DUK_ASSERT(comp_ctx->prev_token.t == DUK_TOK_LBRACKET); max_init_values = DUK__MAX_ARRAY_INIT_VALUES; /* XXX: depend on available temps? */ reg_obj = DUK__ALLOCTEMP(comp_ctx); #if !defined(DUK_USE_PREFER_SIZE) pc_newarr = duk__get_current_pc(comp_ctx); #endif duk__emit_bc(comp_ctx, DUK_OP_NEWARR, reg_obj); /* XXX: patch initial size hint afterwards? */ temp_start = DUK__GETTEMP(comp_ctx); /* * Emit initializers in sets of maximum max_init_values. * Corner cases such as single value initializers do not have * special handling now. * * Elided elements must not be emitted as 'undefined' values, * because such values would be enumerable (which is incorrect). * Also note that trailing elisions must be reflected in the * length of the final array but cause no elements to be actually * inserted. */ curr_idx = 0; init_idx = 0; /* tracks maximum initialized index + 1 */ start_idx = 0; require_comma = 0; for (;;) { num_values = 0; DUK__SETTEMP(comp_ctx, temp_start); if (comp_ctx->curr_token.t == DUK_TOK_RBRACKET) { break; } for (;;) { if (comp_ctx->curr_token.t == DUK_TOK_RBRACKET) { /* the outer loop will recheck and exit */ break; } /* comma check */ if (require_comma) { if (comp_ctx->curr_token.t == DUK_TOK_COMMA) { /* comma after a value, expected */ duk__advance(comp_ctx); require_comma = 0; continue; } else { goto syntax_error; } } else { if (comp_ctx->curr_token.t == DUK_TOK_COMMA) { /* elision - flush */ curr_idx++; duk__advance(comp_ctx); /* if num_values > 0, MPUTARR emitted by outer loop after break */ break; } } /* else an array initializer element */ /* initial index */ if (num_values == 0) { start_idx = curr_idx; reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__emit_load_int32(comp_ctx, reg_temp, (duk_int32_t) start_idx); } reg_temp = DUK__ALLOCTEMP(comp_ctx); /* alloc temp just in case, to update max temp */ DUK__SETTEMP(comp_ctx, reg_temp); duk__expr_toforcedreg(comp_ctx, res, DUK__BP_COMMA /*rbp_flags*/, reg_temp /*forced_reg*/); DUK__SETTEMP(comp_ctx, reg_temp + 1); num_values++; curr_idx++; require_comma = 1; if (num_values >= max_init_values) { /* MPUTARR emitted by outer loop */ break; } } if (num_values > 0) { /* - A is a source register (it's not a write target, but used * to identify the target object) but can be shuffled. * - B cannot be shuffled normally because it identifies a range * of registers, the emitter has special handling for this * (the "no shuffle" flag must not be set). * - C is a non-register number and cannot be shuffled, but * never needs to be. */ duk__emit_a_b_c(comp_ctx, DUK_OP_MPUTARR | DUK__EMIT_FLAG_NO_SHUFFLE_C | DUK__EMIT_FLAG_A_IS_SOURCE, reg_obj, temp_start, (duk_regconst_t) (num_values + 1)); init_idx = start_idx + num_values; /* num_values and temp_start reset at top of outer loop */ } } /* Update initil size for NEWARR, doesn't need to be exact and is * capped at A field limit. */ #if !defined(DUK_USE_PREFER_SIZE) instr = duk__get_instr_ptr(comp_ctx, pc_newarr); instr->ins |= DUK_ENC_OP_A(0, curr_idx > DUK_BC_A_MAX ? DUK_BC_A_MAX : curr_idx); #endif DUK_ASSERT(comp_ctx->curr_token.t == DUK_TOK_RBRACKET); duk__advance(comp_ctx); DUK_DDD(DUK_DDDPRINT("array literal done, curridx=%ld, initidx=%ld", (long) curr_idx, (long) init_idx)); /* trailing elisions? */ if (curr_idx > init_idx) { /* yes, must set array length explicitly */ DUK_DDD(DUK_DDDPRINT("array literal has trailing elisions which affect its length")); reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__emit_load_int32(comp_ctx, reg_temp, (duk_int_t) curr_idx); duk__emit_a_bc(comp_ctx, DUK_OP_SETALEN | DUK__EMIT_FLAG_A_IS_SOURCE, reg_obj, reg_temp); } DUK__SETTEMP(comp_ctx, temp_start); duk__ivalue_regconst(res, reg_obj); return; syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_ARRAY_LITERAL); DUK_WO_NORETURN(return;); } typedef struct { duk_regconst_t reg_obj; duk_regconst_t temp_start; duk_small_uint_t num_pairs; duk_small_uint_t num_total_pairs; } duk__objlit_state; DUK_LOCAL void duk__objlit_flush_keys(duk_compiler_ctx *comp_ctx, duk__objlit_state *st) { if (st->num_pairs > 0) { /* - A is a source register (it's not a write target, but used * to identify the target object) but can be shuffled. * - B cannot be shuffled normally because it identifies a range * of registers, the emitter has special handling for this * (the "no shuffle" flag must not be set). * - C is a non-register number and cannot be shuffled, but * never needs to be. */ DUK_ASSERT(st->num_pairs > 0); duk__emit_a_b_c(comp_ctx, DUK_OP_MPUTOBJ | DUK__EMIT_FLAG_NO_SHUFFLE_C | DUK__EMIT_FLAG_A_IS_SOURCE, st->reg_obj, st->temp_start, (duk_regconst_t) (st->num_pairs * 2)); st->num_total_pairs += st->num_pairs; st->num_pairs = 0; } DUK__SETTEMP(comp_ctx, st->temp_start); } DUK_LOCAL duk_bool_t duk__objlit_load_key(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_token *tok, duk_regconst_t reg_temp) { if (tok->t_nores == DUK_TOK_IDENTIFIER || tok->t_nores == DUK_TOK_STRING) { /* same handling for identifiers and strings */ DUK_ASSERT(tok->str1 != NULL); duk_push_hstring(comp_ctx->thr, tok->str1); } else if (tok->t == DUK_TOK_NUMBER) { /* numbers can be loaded as numbers and coerced on the fly */ duk_push_number(comp_ctx->thr, tok->num); } else { return 1; /* error */ } duk__ivalue_plain_fromstack(comp_ctx, res); DUK__SETTEMP(comp_ctx, reg_temp + 1); duk__ivalue_toforcedreg(comp_ctx, res, reg_temp); DUK__SETTEMP(comp_ctx, reg_temp + 1); return 0; } DUK_LOCAL void duk__nud_object_literal(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk__objlit_state st; duk_regconst_t reg_temp; /* temp reg */ duk_small_uint_t max_init_pairs; /* max # of key-value pairs initialized in one MPUTOBJ set */ duk_bool_t first; /* first value: comma must not precede the value */ duk_bool_t is_set, is_get; /* temps */ #if !defined(DUK_USE_PREFER_SIZE) duk_int_t pc_newobj; duk_compiler_instr *instr; #endif DUK_ASSERT(comp_ctx->prev_token.t == DUK_TOK_LCURLY); max_init_pairs = DUK__MAX_OBJECT_INIT_PAIRS; /* XXX: depend on available temps? */ st.reg_obj = DUK__ALLOCTEMP(comp_ctx); /* target object */ st.temp_start = DUK__GETTEMP(comp_ctx); /* start of MPUTOBJ argument list */ st.num_pairs = 0; /* number of key/value pairs emitted for current MPUTOBJ set */ st.num_total_pairs = 0; /* number of key/value pairs emitted overall */ #if !defined(DUK_USE_PREFER_SIZE) pc_newobj = duk__get_current_pc(comp_ctx); #endif duk__emit_bc(comp_ctx, DUK_OP_NEWOBJ, st.reg_obj); /* * Emit initializers in sets of maximum max_init_pairs keys. * Setter/getter is handled separately and terminates the * current set of initializer values. Corner cases such as * single value initializers do not have special handling now. */ first = 1; for (;;) { /* * ES5 and ES2015+ provide a lot of different PropertyDefinition * formats, see http://www.ecma-international.org/ecma-262/6.0/#sec-object-initializer. * * PropertyName can be IdentifierName (includes reserved words), a string * literal, or a number literal. Note that IdentifierName allows 'get' and * 'set' too, so we need to look ahead to the next token to distinguish: * * { get : 1 } * * and * * { get foo() { return 1 } } * { get get() { return 1 } } // 'get' as getter propertyname * * Finally, a trailing comma is allowed. * * Key name is coerced to string at compile time (and ends up as a * a string constant) even for numeric keys (e.g. "{1:'foo'}"). * These could be emitted using e.g. LDINT, but that seems hardly * worth the effort and would increase code size. */ DUK_DDD(DUK_DDDPRINT("object literal loop, curr_token->t = %ld", (long) comp_ctx->curr_token.t)); if (comp_ctx->curr_token.t == DUK_TOK_RCURLY) { break; } if (first) { first = 0; } else { if (comp_ctx->curr_token.t != DUK_TOK_COMMA) { goto syntax_error; } duk__advance(comp_ctx); if (comp_ctx->curr_token.t == DUK_TOK_RCURLY) { /* trailing comma followed by rcurly */ break; } } /* Advance to get one step of lookup. */ duk__advance(comp_ctx); /* Flush current MPUTOBJ if enough many pairs gathered. */ if (st.num_pairs >= max_init_pairs) { duk__objlit_flush_keys(comp_ctx, &st); DUK_ASSERT(st.num_pairs == 0); } /* Reset temp register state and reserve reg_temp and * reg_temp + 1 for handling the current property. */ DUK__SETTEMP(comp_ctx, st.temp_start + 2 * (duk_regconst_t) st.num_pairs); reg_temp = DUK__ALLOCTEMPS(comp_ctx, 2); /* NOTE: "get" and "set" are not officially ReservedWords and the lexer * currently treats them always like ordinary identifiers (DUK_TOK_GET * and DUK_TOK_SET are unused). They need to be detected based on the * identifier string content. */ is_get = (comp_ctx->prev_token.t == DUK_TOK_IDENTIFIER && comp_ctx->prev_token.str1 == DUK_HTHREAD_STRING_GET(thr)); is_set = (comp_ctx->prev_token.t == DUK_TOK_IDENTIFIER && comp_ctx->prev_token.str1 == DUK_HTHREAD_STRING_SET(thr)); if ((is_get || is_set) && comp_ctx->curr_token.t != DUK_TOK_COLON) { /* getter/setter */ duk_int_t fnum; duk__objlit_flush_keys(comp_ctx, &st); DUK_ASSERT(DUK__GETTEMP(comp_ctx) == st.temp_start); /* 2 regs are guaranteed to be allocated w.r.t. temp_max */ reg_temp = DUK__ALLOCTEMPS(comp_ctx, 2); if (duk__objlit_load_key(comp_ctx, res, &comp_ctx->curr_token, reg_temp) != 0) { goto syntax_error; } /* curr_token = get/set name */ fnum = duk__parse_func_like_fnum(comp_ctx, DUK__FUNC_FLAG_GETSET); duk__emit_a_bc(comp_ctx, DUK_OP_CLOSURE, st.temp_start + 1, (duk_regconst_t) fnum); /* Slot C is used in a non-standard fashion (range of regs), * emitter code has special handling for it (must not set the * "no shuffle" flag). */ duk__emit_a_bc(comp_ctx, (is_get ? DUK_OP_INITGET : DUK_OP_INITSET) | DUK__EMIT_FLAG_A_IS_SOURCE, st.reg_obj, st.temp_start); /* temp_start+0 = key, temp_start+1 = closure */ DUK_ASSERT(st.num_pairs == 0); /* temp state is reset on next loop */ #if defined(DUK_USE_ES6) } else if (comp_ctx->prev_token.t == DUK_TOK_IDENTIFIER && (comp_ctx->curr_token.t == DUK_TOK_COMMA || comp_ctx->curr_token.t == DUK_TOK_RCURLY)) { duk_bool_t load_rc; load_rc = duk__objlit_load_key(comp_ctx, res, &comp_ctx->prev_token, reg_temp); DUK_UNREF(load_rc); DUK_ASSERT(load_rc == 0); /* always succeeds because token is identifier */ duk__ivalue_var_hstring(comp_ctx, res, comp_ctx->prev_token.str1); DUK_ASSERT(DUK__GETTEMP(comp_ctx) == reg_temp + 1); duk__ivalue_toforcedreg(comp_ctx, res, reg_temp + 1); st.num_pairs++; } else if ((comp_ctx->prev_token.t == DUK_TOK_IDENTIFIER || comp_ctx->prev_token.t == DUK_TOK_STRING || comp_ctx->prev_token.t == DUK_TOK_NUMBER) && comp_ctx->curr_token.t == DUK_TOK_LPAREN) { duk_int_t fnum; /* Parsing-wise there's a small hickup here: the token parsing * state is one step too advanced for the function parse helper * compared to other cases. The current solution is an extra * flag to indicate whether function parsing should use the * current or the previous token to starting parsing from. */ if (duk__objlit_load_key(comp_ctx, res, &comp_ctx->prev_token, reg_temp) != 0) { goto syntax_error; } fnum = duk__parse_func_like_fnum(comp_ctx, DUK__FUNC_FLAG_USE_PREVTOKEN | DUK__FUNC_FLAG_METDEF); duk__emit_a_bc(comp_ctx, DUK_OP_CLOSURE, reg_temp + 1, (duk_regconst_t) fnum); st.num_pairs++; #endif /* DUK_USE_ES6 */ } else { #if defined(DUK_USE_ES6) if (comp_ctx->prev_token.t == DUK_TOK_LBRACKET) { /* ES2015 computed property name. Executor ToPropertyKey() * coerces the key at runtime. */ DUK__SETTEMP(comp_ctx, reg_temp); duk__expr_toforcedreg(comp_ctx, res, DUK__BP_FOR_EXPR, reg_temp); duk__advance_expect(comp_ctx, DUK_TOK_RBRACKET); /* XXX: If next token is '(' we're dealing with * the method shorthand with a computed name, * e.g. { [Symbol.for('foo')](a,b) {} }. This * form is not yet supported and causes a * SyntaxError on the DUK_TOK_COLON check below. */ } else #endif /* DUK_USE_ES6 */ { if (duk__objlit_load_key(comp_ctx, res, &comp_ctx->prev_token, reg_temp) != 0) { goto syntax_error; } } duk__advance_expect(comp_ctx, DUK_TOK_COLON); DUK__SETTEMP(comp_ctx, reg_temp + 1); duk__expr_toforcedreg(comp_ctx, res, DUK__BP_COMMA /*rbp_flags*/, reg_temp + 1 /*forced_reg*/); st.num_pairs++; } } /* property loop */ /* Flush remaining properties. */ duk__objlit_flush_keys(comp_ctx, &st); DUK_ASSERT(st.num_pairs == 0); DUK_ASSERT(DUK__GETTEMP(comp_ctx) == st.temp_start); /* Update initial size for NEWOBJ. The init size doesn't need to be * exact as the purpose is just to avoid object resizes in common * cases. The size is capped to field A limit, and will be too high * if the object literal contains duplicate keys (this is harmless but * increases memory traffic if the object is compacted later on). */ #if !defined(DUK_USE_PREFER_SIZE) instr = duk__get_instr_ptr(comp_ctx, pc_newobj); instr->ins |= DUK_ENC_OP_A(0, st.num_total_pairs > DUK_BC_A_MAX ? DUK_BC_A_MAX : st.num_total_pairs); #endif DUK_ASSERT(comp_ctx->curr_token.t == DUK_TOK_RCURLY); duk__advance(comp_ctx); /* No RegExp after object literal. */ duk__ivalue_regconst(res, st.reg_obj); return; syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_OBJECT_LITERAL); DUK_WO_NORETURN(return;); } /* Parse argument list. Arguments are written to temps starting from * "next temp". Returns number of arguments parsed. Expects left paren * to be already eaten, and eats the right paren before returning. */ DUK_LOCAL duk_int_t duk__parse_arguments(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_int_t nargs = 0; duk_regconst_t reg_temp; /* Note: expect that caller has already eaten the left paren */ DUK_DDD(DUK_DDDPRINT("start parsing arguments, prev_token.t=%ld, curr_token.t=%ld", (long) comp_ctx->prev_token.t, (long) comp_ctx->curr_token.t)); for (;;) { if (comp_ctx->curr_token.t == DUK_TOK_RPAREN) { break; } if (nargs > 0) { duk__advance_expect(comp_ctx, DUK_TOK_COMMA); } /* We want the argument expression value to go to "next temp" * without additional moves. That should almost always be the * case, but we double check after expression parsing. * * This is not the cleanest possible approach. */ reg_temp = DUK__ALLOCTEMP(comp_ctx); /* bump up "allocated" reg count, just in case */ DUK__SETTEMP(comp_ctx, reg_temp); /* binding power must be high enough to NOT allow comma expressions directly */ duk__expr_toforcedreg(comp_ctx, res, DUK__BP_COMMA /*rbp_flags*/, reg_temp); /* always allow 'in', coerce to 'tr' just in case */ DUK__SETTEMP(comp_ctx, reg_temp + 1); nargs++; DUK_DDD(DUK_DDDPRINT("argument #%ld written into reg %ld", (long) nargs, (long) reg_temp)); } /* eat the right paren */ duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* RegExp mode does not matter. */ DUK_DDD(DUK_DDDPRINT("end parsing arguments")); return nargs; } DUK_LOCAL duk_bool_t duk__expr_is_empty(duk_compiler_ctx *comp_ctx) { /* empty expressions can be detected conveniently with nud/led counts */ return (comp_ctx->curr_func.nud_count == 0) && (comp_ctx->curr_func.led_count == 0); } DUK_LOCAL void duk__expr_nud(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk_token *tk; duk_regconst_t temp_at_entry; duk_small_uint_t tok; duk_uint32_t args; /* temp variable to pass constants and flags to shared code */ /* * ctx->prev_token token to process with duk__expr_nud() * ctx->curr_token updated by caller * * Note: the token in the switch below has already been eaten. */ temp_at_entry = DUK__GETTEMP(comp_ctx); comp_ctx->curr_func.nud_count++; tk = &comp_ctx->prev_token; tok = tk->t; res->t = DUK_IVAL_NONE; DUK_DDD(DUK_DDDPRINT("duk__expr_nud(), prev_token.t=%ld, allow_in=%ld, paren_level=%ld", (long) tk->t, (long) comp_ctx->curr_func.allow_in, (long) comp_ctx->curr_func.paren_level)); switch (tok) { /* PRIMARY EXPRESSIONS */ case DUK_TOK_THIS: { duk_regconst_t reg_temp; reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__emit_bc(comp_ctx, DUK_OP_LDTHIS, reg_temp); duk__ivalue_regconst(res, reg_temp); return; } case DUK_TOK_IDENTIFIER: { duk__ivalue_var_hstring(comp_ctx, res, tk->str1); return; } case DUK_TOK_NULL: { duk_push_null(thr); goto plain_value; } case DUK_TOK_TRUE: { duk_push_true(thr); goto plain_value; } case DUK_TOK_FALSE: { duk_push_false(thr); goto plain_value; } case DUK_TOK_NUMBER: { duk_push_number(thr, tk->num); goto plain_value; } case DUK_TOK_STRING: { DUK_ASSERT(tk->str1 != NULL); duk_push_hstring(thr, tk->str1); goto plain_value; } case DUK_TOK_REGEXP: { #if defined(DUK_USE_REGEXP_SUPPORT) duk_regconst_t reg_temp; duk_regconst_t rc_re_bytecode; /* const */ duk_regconst_t rc_re_source; /* const */ DUK_ASSERT(tk->str1 != NULL); DUK_ASSERT(tk->str2 != NULL); DUK_DDD(DUK_DDDPRINT("emitting regexp op, str1=%!O, str2=%!O", (duk_heaphdr *) tk->str1, (duk_heaphdr *) tk->str2)); reg_temp = DUK__ALLOCTEMP(comp_ctx); duk_push_hstring(thr, tk->str1); duk_push_hstring(thr, tk->str2); /* [ ... pattern flags ] */ duk_regexp_compile(thr); /* [ ... escaped_source bytecode ] */ rc_re_bytecode = duk__getconst(comp_ctx); rc_re_source = duk__getconst(comp_ctx); duk__emit_a_b_c(comp_ctx, DUK_OP_REGEXP | DUK__EMIT_FLAG_BC_REGCONST, reg_temp /*a*/, rc_re_bytecode /*b*/, rc_re_source /*c*/); duk__ivalue_regconst(res, reg_temp); return; #else /* DUK_USE_REGEXP_SUPPORT */ goto syntax_error; #endif /* DUK_USE_REGEXP_SUPPORT */ } case DUK_TOK_LBRACKET: { DUK_DDD(DUK_DDDPRINT("parsing array literal")); duk__nud_array_literal(comp_ctx, res); return; } case DUK_TOK_LCURLY: { DUK_DDD(DUK_DDDPRINT("parsing object literal")); duk__nud_object_literal(comp_ctx, res); return; } case DUK_TOK_LPAREN: { duk_bool_t prev_allow_in; comp_ctx->curr_func.paren_level++; prev_allow_in = comp_ctx->curr_func.allow_in; comp_ctx->curr_func.allow_in = 1; /* reset 'allow_in' for parenthesized expression */ duk__expr(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); /* Expression, terminates at a ')' */ duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* No RegExp after parenthesized expression. */ comp_ctx->curr_func.allow_in = prev_allow_in; comp_ctx->curr_func.paren_level--; return; } /* MEMBER/NEW/CALL EXPRESSIONS */ case DUK_TOK_NEW: { /* * Parsing an expression starting with 'new' is tricky because * there are multiple possible productions deriving from * LeftHandSideExpression which begin with 'new'. * * We currently resort to one-token lookahead to distinguish the * cases. Hopefully this is correct. The binding power must be * such that parsing ends at an LPAREN (CallExpression) but not at * a PERIOD or LBRACKET (MemberExpression). * * See doc/compiler.rst for discussion on the parsing approach, * and testcases/test-dev-new.js for a bunch of documented tests. */ duk_regconst_t reg_target; duk_int_t nargs; DUK_DDD(DUK_DDDPRINT("begin parsing new expression")); reg_target = DUK__ALLOCTEMPS(comp_ctx, 2); #if defined(DUK_USE_ES6) if (comp_ctx->curr_token.t == DUK_TOK_PERIOD) { /* new.target */ DUK_DDD(DUK_DDDPRINT("new.target")); duk__advance(comp_ctx); if (comp_ctx->curr_token.t_nores != DUK_TOK_IDENTIFIER || !duk_hstring_equals_ascii_cstring(comp_ctx->curr_token.str1, "target")) { goto syntax_error_newtarget; } if (comp_ctx->curr_func.is_global) { goto syntax_error_newtarget; } duk__advance(comp_ctx); duk__emit_bc(comp_ctx, DUK_OP_NEWTARGET, reg_target); duk__ivalue_regconst(res, reg_target); return; } #endif /* DUK_USE_ES6 */ duk__expr_toforcedreg(comp_ctx, res, DUK__BP_CALL /*rbp_flags*/, reg_target /*forced_reg*/); duk__emit_bc(comp_ctx, DUK_OP_NEWOBJ, reg_target + 1); /* default instance */ DUK__SETTEMP(comp_ctx, reg_target + 2); /* XXX: 'new obj.noSuch()' doesn't use GETPROPC now which * makes the error message worse than for obj.noSuch(). */ if (comp_ctx->curr_token.t == DUK_TOK_LPAREN) { /* 'new' MemberExpression Arguments */ DUK_DDD(DUK_DDDPRINT("new expression has argument list")); duk__advance(comp_ctx); nargs = duk__parse_arguments(comp_ctx, res); /* parse args starting from "next temp", reg_target + 1 */ /* right paren eaten */ } else { /* 'new' MemberExpression */ DUK_DDD(DUK_DDDPRINT("new expression has no argument list")); nargs = 0; } duk__emit_a_bc(comp_ctx, DUK_OP_CALL0 | DUK_BC_CALL_FLAG_CONSTRUCT, nargs /*num_args*/, reg_target /*target*/); DUK_DDD(DUK_DDDPRINT("end parsing new expression")); duk__ivalue_regconst(res, reg_target); return; } /* FUNCTION EXPRESSIONS */ case DUK_TOK_FUNCTION: { /* Function expression. Note that any statement beginning with 'function' * is handled by the statement parser as a function declaration, or a * non-standard function expression/statement (or a SyntaxError). We only * handle actual function expressions (occurring inside an expression) here. * * O(depth^2) parse count for inner functions is handled by recording a * lexer offset on the first compilation pass, so that the function can * be efficiently skipped on the second pass. This is encapsulated into * duk__parse_func_like_fnum(). */ duk_regconst_t reg_temp; duk_int_t fnum; reg_temp = DUK__ALLOCTEMP(comp_ctx); /* curr_token follows 'function' */ fnum = duk__parse_func_like_fnum(comp_ctx, 0 /*flags*/); DUK_DDD(DUK_DDDPRINT("parsed inner function -> fnum %ld", (long) fnum)); duk__emit_a_bc(comp_ctx, DUK_OP_CLOSURE, reg_temp /*a*/, (duk_regconst_t) fnum /*bc*/); duk__ivalue_regconst(res, reg_temp); return; } /* UNARY EXPRESSIONS */ case DUK_TOK_DELETE: { /* Delete semantics are a bit tricky. The description in E5 specification * is kind of confusing, because it distinguishes between resolvability of * a reference (which is only known at runtime) seemingly at compile time * (= SyntaxError throwing). */ duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ if (res->t == DUK_IVAL_VAR) { /* not allowed in strict mode, regardless of whether resolves; * in non-strict mode DELVAR handles both non-resolving and * resolving cases (the specification description is a bit confusing). */ duk_regconst_t reg_temp; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; if (comp_ctx->curr_func.is_strict) { DUK_ERROR_SYNTAX(thr, DUK_STR_CANNOT_DELETE_IDENTIFIER); DUK_WO_NORETURN(return;); } DUK__SETTEMP(comp_ctx, temp_at_entry); reg_temp = DUK__ALLOCTEMP(comp_ctx); duk_dup(thr, res->x1.valstack_idx); if (duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { /* register bound variables are non-configurable -> always false */ duk__emit_bc(comp_ctx, DUK_OP_LDFALSE, reg_temp); } else { duk_dup(thr, res->x1.valstack_idx); rc_varname = duk__getconst(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_DELVAR, reg_temp, rc_varname); } duk__ivalue_regconst(res, reg_temp); } else if (res->t == DUK_IVAL_PROP) { duk_regconst_t reg_temp; duk_regconst_t reg_obj; duk_regconst_t rc_key; DUK__SETTEMP(comp_ctx, temp_at_entry); reg_temp = DUK__ALLOCTEMP(comp_ctx); reg_obj = duk__ispec_toregconst_raw(comp_ctx, &res->x1, -1 /*forced_reg*/, 0 /*flags*/); /* don't allow const */ rc_key = duk__ispec_toregconst_raw(comp_ctx, &res->x2, -1 /*forced_reg*/, DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); duk__emit_a_b_c(comp_ctx, DUK_OP_DELPROP | DUK__EMIT_FLAG_BC_REGCONST, reg_temp, reg_obj, rc_key); duk__ivalue_regconst(res, reg_temp); } else { /* non-Reference deletion is always 'true', even in strict mode */ duk_push_true(thr); goto plain_value; } return; } case DUK_TOK_VOID: { duk__expr_toplain_ignore(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ duk_push_undefined(thr); goto plain_value; } case DUK_TOK_TYPEOF: { /* 'typeof' must handle unresolvable references without throwing * a ReferenceError (E5 Section 11.4.3). Register mapped values * will never be unresolvable so special handling is only required * when an identifier is a "slow path" one. */ duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ if (res->t == DUK_IVAL_VAR) { duk_regconst_t reg_varbind; duk_regconst_t rc_varname; duk_regconst_t reg_temp; duk_dup(thr, res->x1.valstack_idx); if (!duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { DUK_DDD(DUK_DDDPRINT("typeof for an identifier name which could not be resolved " "at compile time, need to use special run-time handling")); reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_TYPEOFID, reg_temp, rc_varname); duk__ivalue_regconst(res, reg_temp); return; } } args = DUK_OP_TYPEOF; goto unary; } case DUK_TOK_INCREMENT: { args = (DUK_OP_PREINCP << 8) + DUK_OP_PREINCR; goto preincdec; } case DUK_TOK_DECREMENT: { args = (DUK_OP_PREDECP << 8) + DUK_OP_PREDECR; goto preincdec; } case DUK_TOK_ADD: { /* unary plus */ duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ if (res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_VALUE && duk_is_number(thr, res->x1.valstack_idx)) { /* unary plus of a number is identity */ return; } args = DUK_OP_UNP; goto unary; } case DUK_TOK_SUB: { /* unary minus */ duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ if (res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_VALUE && duk_is_number(thr, res->x1.valstack_idx)) { /* this optimization is important to handle negative literals * (which are not directly provided by the lexical grammar) */ duk_tval *tv_num; duk_double_union du; tv_num = DUK_GET_TVAL_POSIDX(thr, res->x1.valstack_idx); DUK_ASSERT(tv_num != NULL); DUK_ASSERT(DUK_TVAL_IS_NUMBER(tv_num)); du.d = DUK_TVAL_GET_NUMBER(tv_num); du.d = -du.d; DUK_DBLUNION_NORMALIZE_NAN_CHECK(&du); DUK_TVAL_SET_NUMBER(tv_num, du.d); return; } args = DUK_OP_UNM; goto unary; } case DUK_TOK_BNOT: { duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ args = DUK_OP_BNOT; goto unary; } case DUK_TOK_LNOT: { duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ if (res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_VALUE) { /* Very minimal inlining to handle common idioms '!0' and '!1', * and also boolean arguments like '!false' and '!true'. */ duk_tval *tv_val; tv_val = DUK_GET_TVAL_POSIDX(thr, res->x1.valstack_idx); DUK_ASSERT(tv_val != NULL); if (DUK_TVAL_IS_NUMBER(tv_val)) { duk_double_t d; d = DUK_TVAL_GET_NUMBER(tv_val); if (d == 0.0) { /* Matches both +0 and -0 on purpose. */ DUK_DDD(DUK_DDDPRINT("inlined lnot: !0 -> true")); DUK_TVAL_SET_BOOLEAN_TRUE(tv_val); return; } else if (d == 1.0) { DUK_DDD(DUK_DDDPRINT("inlined lnot: !1 -> false")); DUK_TVAL_SET_BOOLEAN_FALSE(tv_val); return; } } else if (DUK_TVAL_IS_BOOLEAN(tv_val)) { duk_small_uint_t v; v = DUK_TVAL_GET_BOOLEAN(tv_val); DUK_DDD(DUK_DDDPRINT("inlined lnot boolean: %ld", (long) v)); DUK_ASSERT(v == 0 || v == 1); DUK_TVAL_SET_BOOLEAN(tv_val, v ^ 0x01); return; } } args = DUK_OP_LNOT; goto unary; } } /* end switch */ DUK_ERROR_SYNTAX(thr, DUK_STR_PARSE_ERROR); DUK_WO_NORETURN(return;); unary: { /* Unary opcodes use just the 'BC' register source because it * matches current shuffle limits, and maps cleanly to 16 high * bits of the opcode. */ duk_regconst_t reg_src, reg_res; reg_src = duk__ivalue_toregconst_raw(comp_ctx, res, -1 /*forced_reg*/, 0 /*flags*/); if (DUK__ISREG_TEMP(comp_ctx, reg_src)) { reg_res = reg_src; } else { reg_res = DUK__ALLOCTEMP(comp_ctx); } duk__emit_a_bc(comp_ctx, args, reg_res, reg_src); duk__ivalue_regconst(res, reg_res); return; } preincdec: { /* preincrement and predecrement */ duk_regconst_t reg_res; duk_small_uint_t args_op1 = args & 0xff; /* DUK_OP_PREINCR/DUK_OP_PREDECR */ duk_small_uint_t args_op2 = args >> 8; /* DUK_OP_PREINCP_RR/DUK_OP_PREDECP_RR */ /* Specific assumptions for opcode numbering. */ DUK_ASSERT(DUK_OP_PREINCR + 4 == DUK_OP_PREINCV); DUK_ASSERT(DUK_OP_PREDECR + 4 == DUK_OP_PREDECV); reg_res = DUK__ALLOCTEMP(comp_ctx); duk__expr(comp_ctx, res, DUK__BP_MULTIPLICATIVE /*rbp_flags*/); /* UnaryExpression */ if (res->t == DUK_IVAL_VAR) { duk_hstring *h_varname; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; h_varname = duk_known_hstring(thr, res->x1.valstack_idx); if (duk__hstring_is_eval_or_arguments_in_strict_mode(comp_ctx, h_varname)) { goto syntax_error; } duk_dup(thr, res->x1.valstack_idx); if (duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { duk__emit_a_bc(comp_ctx, args_op1, /* e.g. DUK_OP_PREINCR */ reg_res, reg_varbind); } else { duk__emit_a_bc(comp_ctx, args_op1 + 4, /* e.g. DUK_OP_PREINCV */ reg_res, rc_varname); } DUK_DDD(DUK_DDDPRINT("preincdec to '%!O' -> reg_varbind=%ld, rc_varname=%ld", (duk_heaphdr *) h_varname, (long) reg_varbind, (long) rc_varname)); } else if (res->t == DUK_IVAL_PROP) { duk_regconst_t reg_obj; /* allocate to reg only (not const) */ duk_regconst_t rc_key; reg_obj = duk__ispec_toregconst_raw(comp_ctx, &res->x1, -1 /*forced_reg*/, 0 /*flags*/); /* don't allow const */ rc_key = duk__ispec_toregconst_raw(comp_ctx, &res->x2, -1 /*forced_reg*/, DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); duk__emit_a_b_c(comp_ctx, args_op2 | DUK__EMIT_FLAG_BC_REGCONST, /* e.g. DUK_OP_PREINCP */ reg_res, reg_obj, rc_key); } else { /* Technically return value is not needed because INVLHS will * unconditially throw a ReferenceError. Coercion is necessary * for proper semantics (consider ToNumber() called for an object). * Use DUK_OP_UNP with a dummy register to get ToNumber(). */ duk__ivalue_toforcedreg(comp_ctx, res, reg_res); duk__emit_bc(comp_ctx, DUK_OP_UNP, reg_res); /* for side effects, result ignored */ duk__emit_op_only(comp_ctx, DUK_OP_INVLHS); } DUK__SETTEMP(comp_ctx, reg_res + 1); duk__ivalue_regconst(res, reg_res); return; } plain_value: { /* Stack top contains plain value */ duk__ivalue_plain_fromstack(comp_ctx, res); return; } #if defined(DUK_USE_ES6) syntax_error_newtarget: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_NEWTARGET); DUK_WO_NORETURN(return;); #endif syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_EXPRESSION); DUK_WO_NORETURN(return;); } /* XXX: add flag to indicate whether caller cares about return value; this * affects e.g. handling of assignment expressions. This change needs API * changes elsewhere too. */ DUK_LOCAL void duk__expr_led(duk_compiler_ctx *comp_ctx, duk_ivalue *left, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk_token *tk; duk_small_uint_t tok; duk_uint32_t args; /* temp variable to pass constants and flags to shared code */ /* * ctx->prev_token token to process with duk__expr_led() * ctx->curr_token updated by caller */ comp_ctx->curr_func.led_count++; /* The token in the switch has already been eaten here */ tk = &comp_ctx->prev_token; tok = tk->t; DUK_DDD(DUK_DDDPRINT("duk__expr_led(), prev_token.t=%ld, allow_in=%ld, paren_level=%ld", (long) tk->t, (long) comp_ctx->curr_func.allow_in, (long) comp_ctx->curr_func.paren_level)); /* XXX: default priority for infix operators is duk__expr_lbp(tok) -> get it here? */ switch (tok) { /* PRIMARY EXPRESSIONS */ case DUK_TOK_PERIOD: { /* Property access expressions are critical for correct LHS ordering, * see comments in duk__expr()! * * A conservative approach would be to use duk__ivalue_totempconst() * for 'left'. However, allowing a reg-bound variable seems safe here * and is nice because "foo.bar" is a common expression. If the ivalue * is used in an expression a GETPROP will occur before any changes to * the base value can occur. If the ivalue is used as an assignment * LHS, the assignment code will ensure the base value is safe from * RHS mutation. */ /* XXX: This now coerces an identifier into a GETVAR to a temp, which * causes an extra LDREG in call setup. It's sufficient to coerce to a * unary ivalue? */ duk__ivalue_toplain(comp_ctx, left); /* NB: must accept reserved words as property name */ if (comp_ctx->curr_token.t_nores != DUK_TOK_IDENTIFIER) { DUK_ERROR_SYNTAX(thr, DUK_STR_EXPECTED_IDENTIFIER); DUK_WO_NORETURN(return;); } res->t = DUK_IVAL_PROP; duk__copy_ispec(comp_ctx, &left->x1, &res->x1); /* left.x1 -> res.x1 */ DUK_ASSERT(comp_ctx->curr_token.str1 != NULL); duk_push_hstring(thr, comp_ctx->curr_token.str1); duk_replace(thr, res->x2.valstack_idx); res->x2.t = DUK_ISPEC_VALUE; /* special RegExp literal handling after IdentifierName */ comp_ctx->curr_func.reject_regexp_in_adv = 1; duk__advance(comp_ctx); return; } case DUK_TOK_LBRACKET: { /* Property access expressions are critical for correct LHS ordering, * see comments in duk__expr()! */ /* XXX: optimize temp reg use */ /* XXX: similar coercion issue as in DUK_TOK_PERIOD */ /* XXX: coerce to regs? it might be better for enumeration use, where the * same PROP ivalue is used multiple times. Or perhaps coerce PROP further * there? */ /* XXX: for simple cases like x['y'] an unnecessary LDREG is * emitted for the base value; could avoid it if we knew that * the key expression is safe (e.g. just a single literal). */ /* The 'left' value must not be a register bound variable * because it may be mutated during the rest of the expression * and E5.1 Section 11.2.1 specifies the order of evaluation * so that the base value is evaluated first. * See: test-bug-nested-prop-mutate.js. */ duk__ivalue_totempconst(comp_ctx, left); duk__expr_toplain(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); /* Expression, ']' terminates */ duk__advance_expect(comp_ctx, DUK_TOK_RBRACKET); res->t = DUK_IVAL_PROP; duk__copy_ispec(comp_ctx, &res->x1, &res->x2); /* res.x1 -> res.x2 */ duk__copy_ispec(comp_ctx, &left->x1, &res->x1); /* left.x1 -> res.x1 */ return; } case DUK_TOK_LPAREN: { /* function call */ duk_regconst_t reg_cs = DUK__ALLOCTEMPS(comp_ctx, 2); duk_int_t nargs; duk_small_uint_t call_op = DUK_OP_CALL0; /* XXX: attempt to get the call result to "next temp" whenever * possible to avoid unnecessary register shuffles. */ /* * Setup call: target and 'this' binding. Three cases: * * 1. Identifier base (e.g. "foo()") * 2. Property base (e.g. "foo.bar()") * 3. Register base (e.g. "foo()()"; i.e. when a return value is a function) */ if (left->t == DUK_IVAL_VAR) { duk_hstring *h_varname; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; DUK_DDD(DUK_DDDPRINT("function call with identifier base")); h_varname = duk_known_hstring(thr, left->x1.valstack_idx); if (h_varname == DUK_HTHREAD_STRING_EVAL(thr)) { /* Potential direct eval call detected, flag the CALL * so that a run-time "direct eval" check is made and * special behavior may be triggered. Note that this * does not prevent 'eval' from being register bound. */ DUK_DDD(DUK_DDDPRINT("function call with identifier 'eval' " "-> using EVALCALL, marking function " "as may_direct_eval")); call_op |= DUK_BC_CALL_FLAG_CALLED_AS_EVAL; comp_ctx->curr_func.may_direct_eval = 1; } duk_dup(thr, left->x1.valstack_idx); if (duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { duk__emit_a_bc(comp_ctx, DUK_OP_CSREG | DUK__EMIT_FLAG_A_IS_SOURCE, reg_varbind, reg_cs + 0); } else { /* XXX: expand target register or constant field to * reduce shuffling. */ DUK_ASSERT(DUK__ISCONST(rc_varname)); duk__emit_a_b(comp_ctx, DUK_OP_CSVAR | DUK__EMIT_FLAG_BC_REGCONST, reg_cs + 0, rc_varname); } } else if (left->t == DUK_IVAL_PROP) { /* Call through a property lookup, E5 Section 11.2.3, step 6.a.i, * E5 Section 10.4.3. There used to be a separate CSPROP opcode * but a typical call setup took 3 opcodes (e.g. LDREG, LDCONST, * CSPROP) and the same can be achieved with ordinary loads. */ #if defined(DUK_USE_VERBOSE_ERRORS) duk_regconst_t reg_key; #endif DUK_DDD(DUK_DDDPRINT("function call with property base")); /* XXX: For Math.sin() this generates: LDCONST + LDREG + * GETPROPC + call. The LDREG is unnecessary because LDCONST * could be loaded directly into reg_cs + 1. This doesn't * happen now because a variable cannot be in left->x1 of a * DUK_IVAL_PROP. We could notice that left->x1 is a temp * and reuse, but it would still be in the wrong position * (reg_cs + 0 rather than reg_cs + 1). */ duk__ispec_toforcedreg(comp_ctx, &left->x1, reg_cs + 1); /* base */ #if defined(DUK_USE_VERBOSE_ERRORS) reg_key = duk__ispec_toregconst_raw(comp_ctx, &left->x2, -1, DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); duk__emit_a_b_c(comp_ctx, DUK_OP_GETPROPC | DUK__EMIT_FLAG_BC_REGCONST, reg_cs + 0, reg_cs + 1, reg_key); #else duk__ivalue_toforcedreg(comp_ctx, left, reg_cs + 0); /* base[key] */ #endif } else { DUK_DDD(DUK_DDDPRINT("function call with register base")); duk__ivalue_toforcedreg(comp_ctx, left, reg_cs + 0); #if 0 duk__emit_a_bc(comp_ctx, DUK_OP_CSREG | DUK__EMIT_FLAG_A_IS_SOURCE, reg_cs + 0, reg_cs + 0); /* in-place setup */ #endif /* Because of in-place setup, REGCS is equivalent to * just this LDUNDEF. */ duk__emit_bc(comp_ctx, DUK_OP_LDUNDEF, reg_cs + 1); } DUK__SETTEMP(comp_ctx, reg_cs + 2); nargs = duk__parse_arguments(comp_ctx, res); /* parse args starting from "next temp" */ /* Tailcalls are handled by back-patching the already emitted opcode * later in return statement parser. */ duk__emit_a_bc(comp_ctx, call_op, (duk_regconst_t) nargs /*numargs*/, reg_cs /*basereg*/); DUK__SETTEMP(comp_ctx, reg_cs + 1); /* result in csreg */ duk__ivalue_regconst(res, reg_cs); return; } /* POSTFIX EXPRESSION */ case DUK_TOK_INCREMENT: { args = (DUK_OP_POSTINCP_RR << 16) + (DUK_OP_POSTINCR << 8) + 0; goto postincdec; } case DUK_TOK_DECREMENT: { args = (DUK_OP_POSTDECP_RR << 16) + (DUK_OP_POSTDECR << 8) + 0; goto postincdec; } /* EXPONENTIATION EXPRESSION */ #if defined(DUK_USE_ES7_EXP_OPERATOR) case DUK_TOK_EXP: { args = (DUK_OP_EXP << 8) + DUK__BP_EXPONENTIATION - 1; /* UnaryExpression */ goto binary; } #endif /* MULTIPLICATIVE EXPRESSION */ case DUK_TOK_MUL: { args = (DUK_OP_MUL << 8) + DUK__BP_MULTIPLICATIVE; /* ExponentiationExpression */ goto binary; } case DUK_TOK_DIV: { args = (DUK_OP_DIV << 8) + DUK__BP_MULTIPLICATIVE; /* ExponentiationExpression */ goto binary; } case DUK_TOK_MOD: { args = (DUK_OP_MOD << 8) + DUK__BP_MULTIPLICATIVE; /* ExponentiationExpression */ goto binary; } /* ADDITIVE EXPRESSION */ case DUK_TOK_ADD: { args = (DUK_OP_ADD << 8) + DUK__BP_ADDITIVE; /* MultiplicativeExpression */ goto binary; } case DUK_TOK_SUB: { args = (DUK_OP_SUB << 8) + DUK__BP_ADDITIVE; /* MultiplicativeExpression */ goto binary; } /* SHIFT EXPRESSION */ case DUK_TOK_ALSHIFT: { /* << */ args = (DUK_OP_BASL << 8) + DUK__BP_SHIFT; goto binary; } case DUK_TOK_ARSHIFT: { /* >> */ args = (DUK_OP_BASR << 8) + DUK__BP_SHIFT; goto binary; } case DUK_TOK_RSHIFT: { /* >>> */ args = (DUK_OP_BLSR << 8) + DUK__BP_SHIFT; goto binary; } /* RELATIONAL EXPRESSION */ case DUK_TOK_LT: { /* < */ args = (DUK_OP_LT << 8) + DUK__BP_RELATIONAL; goto binary; } case DUK_TOK_GT: { args = (DUK_OP_GT << 8) + DUK__BP_RELATIONAL; goto binary; } case DUK_TOK_LE: { args = (DUK_OP_LE << 8) + DUK__BP_RELATIONAL; goto binary; } case DUK_TOK_GE: { args = (DUK_OP_GE << 8) + DUK__BP_RELATIONAL; goto binary; } case DUK_TOK_INSTANCEOF: { args = (DUK_OP_INSTOF << 8) + DUK__BP_RELATIONAL; goto binary; } case DUK_TOK_IN: { args = (DUK_OP_IN << 8) + DUK__BP_RELATIONAL; goto binary; } /* EQUALITY EXPRESSION */ case DUK_TOK_EQ: { args = (DUK_OP_EQ << 8) + DUK__BP_EQUALITY; goto binary; } case DUK_TOK_NEQ: { args = (DUK_OP_NEQ << 8) + DUK__BP_EQUALITY; goto binary; } case DUK_TOK_SEQ: { args = (DUK_OP_SEQ << 8) + DUK__BP_EQUALITY; goto binary; } case DUK_TOK_SNEQ: { args = (DUK_OP_SNEQ << 8) + DUK__BP_EQUALITY; goto binary; } /* BITWISE EXPRESSIONS */ case DUK_TOK_BAND: { args = (DUK_OP_BAND << 8) + DUK__BP_BAND; goto binary; } case DUK_TOK_BXOR: { args = (DUK_OP_BXOR << 8) + DUK__BP_BXOR; goto binary; } case DUK_TOK_BOR: { args = (DUK_OP_BOR << 8) + DUK__BP_BOR; goto binary; } /* LOGICAL EXPRESSIONS */ case DUK_TOK_LAND: { /* syntactically left-associative but parsed as right-associative */ args = (1 << 8) + DUK__BP_LAND - 1; goto binary_logical; } case DUK_TOK_LOR: { /* syntactically left-associative but parsed as right-associative */ args = (0 << 8) + DUK__BP_LOR - 1; goto binary_logical; } /* CONDITIONAL EXPRESSION */ case DUK_TOK_QUESTION: { /* XXX: common reg allocation need is to reuse a sub-expression's temp reg, * but only if it really is a temp. Nothing fancy here now. */ duk_regconst_t reg_temp; duk_int_t pc_jump1; duk_int_t pc_jump2; reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__ivalue_toforcedreg(comp_ctx, left, reg_temp); duk__emit_if_true_skip(comp_ctx, reg_temp); pc_jump1 = duk__emit_jump_empty(comp_ctx); /* jump to false */ duk__expr_toforcedreg(comp_ctx, res, DUK__BP_COMMA /*rbp_flags*/, reg_temp /*forced_reg*/); /* AssignmentExpression */ duk__advance_expect(comp_ctx, DUK_TOK_COLON); pc_jump2 = duk__emit_jump_empty(comp_ctx); /* jump to end */ duk__patch_jump_here(comp_ctx, pc_jump1); duk__expr_toforcedreg(comp_ctx, res, DUK__BP_COMMA /*rbp_flags*/, reg_temp /*forced_reg*/); /* AssignmentExpression */ duk__patch_jump_here(comp_ctx, pc_jump2); DUK__SETTEMP(comp_ctx, reg_temp + 1); duk__ivalue_regconst(res, reg_temp); return; } /* ASSIGNMENT EXPRESSION */ case DUK_TOK_EQUALSIGN: { /* * Assignments are right associative, allows e.g. * a = 5; * a += b = 9; // same as a += (b = 9) * -> expression value 14, a = 14, b = 9 * * Right associativiness is reflected in the BP for recursion, * "-1" ensures assignment operations are allowed. * * XXX: just use DUK__BP_COMMA (i.e. no need for 2-step bp levels)? */ args = (DUK_OP_NONE << 8) + DUK__BP_ASSIGNMENT - 1; /* DUK_OP_NONE marks a 'plain' assignment */ goto assign; } case DUK_TOK_ADD_EQ: { /* right associative */ args = (DUK_OP_ADD << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_SUB_EQ: { /* right associative */ args = (DUK_OP_SUB << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_MUL_EQ: { /* right associative */ args = (DUK_OP_MUL << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_DIV_EQ: { /* right associative */ args = (DUK_OP_DIV << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_MOD_EQ: { /* right associative */ args = (DUK_OP_MOD << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } #if defined(DUK_USE_ES7_EXP_OPERATOR) case DUK_TOK_EXP_EQ: { /* right associative */ args = (DUK_OP_EXP << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } #endif case DUK_TOK_ALSHIFT_EQ: { /* right associative */ args = (DUK_OP_BASL << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_ARSHIFT_EQ: { /* right associative */ args = (DUK_OP_BASR << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_RSHIFT_EQ: { /* right associative */ args = (DUK_OP_BLSR << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_BAND_EQ: { /* right associative */ args = (DUK_OP_BAND << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_BOR_EQ: { /* right associative */ args = (DUK_OP_BOR << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } case DUK_TOK_BXOR_EQ: { /* right associative */ args = (DUK_OP_BXOR << 8) + DUK__BP_ASSIGNMENT - 1; goto assign; } /* COMMA */ case DUK_TOK_COMMA: { /* right associative */ duk__ivalue_toplain_ignore(comp_ctx, left); /* need side effects, not value */ duk__expr_toplain(comp_ctx, res, DUK__BP_COMMA - 1 /*rbp_flags*/); /* return 'res' (of right part) as our result */ return; } default: { break; } } DUK_D(DUK_DPRINT("parse error: unexpected token: %ld", (long) tok)); DUK_ERROR_SYNTAX(thr, DUK_STR_PARSE_ERROR); DUK_WO_NORETURN(return;); #if 0 /* XXX: shared handling for 'duk__expr_lhs'? */ if (comp_ctx->curr_func.paren_level == 0 && XXX) { comp_ctx->curr_func.duk__expr_lhs = 0; } #endif binary: /* * Shared handling of binary operations * * args = (opcode << 8) + rbp */ { duk__ivalue_toplain(comp_ctx, left); duk__expr_toplain(comp_ctx, res, args & 0xff /*rbp_flags*/); /* combine left->x1 and res->x1 (right->x1, really) -> (left->x1 OP res->x1) */ DUK_ASSERT(left->t == DUK_IVAL_PLAIN); DUK_ASSERT(res->t == DUK_IVAL_PLAIN); res->t = DUK_IVAL_ARITH; res->op = (args >> 8) & 0xff; res->x2.t = res->x1.t; res->x2.regconst = res->x1.regconst; duk_copy(thr, res->x1.valstack_idx, res->x2.valstack_idx); res->x1.t = left->x1.t; res->x1.regconst = left->x1.regconst; duk_copy(thr, left->x1.valstack_idx, res->x1.valstack_idx); DUK_DDD(DUK_DDDPRINT("binary op, res: t=%ld, x1.t=%ld, x1.regconst=0x%08lx, x2.t=%ld, x2.regconst=0x%08lx", (long) res->t, (long) res->x1.t, (unsigned long) res->x1.regconst, (long) res->x2.t, (unsigned long) res->x2.regconst)); return; } binary_logical: /* * Shared handling for logical AND and logical OR. * * args = (truthval << 8) + rbp * * Truthval determines when to skip right-hand-side. * For logical AND truthval=1, for logical OR truthval=0. * * See doc/compiler.rst for discussion on compiling logical * AND and OR expressions. The approach here is very simplistic, * generating extra jumps and multiple evaluations of truth values, * but generates code on-the-fly with only local back-patching. * * Both logical AND and OR are syntactically left-associated. * However, logical ANDs are compiled as right associative * expressions, i.e. "A && B && C" as "A && (B && C)", to allow * skip jumps to skip over the entire tail. Similarly for logical OR. */ { duk_regconst_t reg_temp; duk_int_t pc_jump; duk_small_uint_t args_truthval = args >> 8; duk_small_uint_t args_rbp = args & 0xff; /* XXX: unoptimal use of temps, resetting */ reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__ivalue_toforcedreg(comp_ctx, left, reg_temp); DUK_ASSERT(DUK__ISREG(reg_temp)); duk__emit_bc(comp_ctx, (args_truthval ? DUK_OP_IFTRUE_R : DUK_OP_IFFALSE_R), reg_temp); /* skip jump conditionally */ pc_jump = duk__emit_jump_empty(comp_ctx); duk__expr_toforcedreg(comp_ctx, res, args_rbp /*rbp_flags*/, reg_temp /*forced_reg*/); duk__patch_jump_here(comp_ctx, pc_jump); duk__ivalue_regconst(res, reg_temp); return; } assign: /* * Shared assignment expression handling * * args = (opcode << 8) + rbp * * If 'opcode' is DUK_OP_NONE, plain assignment without arithmetic. * Syntactically valid left-hand-side forms which are not accepted as * left-hand-side values (e.g. as in "f() = 1") must NOT cause a * SyntaxError, but rather a run-time ReferenceError. * * When evaluating X = Y, the LHS (X) is conceptually evaluated * to a temporary first. The RHS is then evaluated. Finally, the * is applied to the initial value of RHS (not the value after * RHS evaluation), and written to X. Doing so concretely generates * inefficient code so we'd like to avoid the temporary when possible. * See: https://github.com/svaarala/duktape/pull/992. * * The expression value (final LHS value, written to RHS) is * conceptually copied into a fresh temporary so that it won't * change even if the LHS/RHS values change in outer expressions. * For example, it'd be generally incorrect for the expression value * to be the RHS register binding, unless there's a guarantee that it * won't change during further expression evaluation. Using the * temporary concretely produces inefficient bytecode, so we try to * avoid the extra temporary for some known-to-be-safe cases. * Currently the only safe case we detect is a "top level assignment", * for example "x = y + z;", where the assignment expression value is * ignored. * See: test-dev-assign-expr.js and test-bug-assign-mutate-gh381.js. */ { duk_small_uint_t args_op = args >> 8; duk_small_uint_t args_rbp = args & 0xff; duk_bool_t toplevel_assign; /* XXX: here we need to know if 'left' is left-hand-side compatible. * That information is no longer available from current expr parsing * state; it would need to be carried into the 'left' ivalue or by * some other means. */ /* A top-level assignment is e.g. "x = y;". For these it's safe * to use the RHS as-is as the expression value, even if the RHS * is a reg-bound identifier. The RHS ('res') is right associative * so it has consumed all other assignment level operations; the * only relevant lower binding power construct is comma operator * which will ignore the expression value provided here. Usually * the top level assignment expression value is ignored, but it * is relevant for e.g. eval code. */ toplevel_assign = (comp_ctx->curr_func.nud_count == 1 && /* one token before */ comp_ctx->curr_func.led_count == 1); /* one operator (= assign) */ DUK_DDD(DUK_DDDPRINT("assignment: nud_count=%ld, led_count=%ld, toplevel_assign=%ld", (long) comp_ctx->curr_func.nud_count, (long) comp_ctx->curr_func.led_count, (long) toplevel_assign)); if (left->t == DUK_IVAL_VAR) { duk_hstring *h_varname; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; DUK_ASSERT(left->x1.t == DUK_ISPEC_VALUE); /* LHS is already side effect free */ h_varname = duk_known_hstring(thr, left->x1.valstack_idx); if (duk__hstring_is_eval_or_arguments_in_strict_mode(comp_ctx, h_varname)) { /* E5 Section 11.13.1 (and others for other assignments), step 4. */ goto syntax_error_lvalue; } duk_dup(thr, left->x1.valstack_idx); (void) duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname); if (args_op == DUK_OP_NONE) { duk__expr(comp_ctx, res, args_rbp /*rbp_flags*/); if (toplevel_assign) { /* Any 'res' will do. */ DUK_DDD(DUK_DDDPRINT("plain assignment, toplevel assign, use as is")); } else { /* 'res' must be a plain ivalue, and not register-bound variable. */ DUK_DDD(DUK_DDDPRINT("plain assignment, not toplevel assign, ensure not a reg-bound identifier")); if (res->t != DUK_IVAL_PLAIN || (res->x1.t == DUK_ISPEC_REGCONST && DUK__ISREG_NOTTEMP(comp_ctx, res->x1.regconst))) { duk__ivalue_totempconst(comp_ctx, res); } } } else { /* For X = Y we need to evaluate the pre-op * value of X before evaluating the RHS: the RHS * can change X, but when we do we must use * the pre-op value. */ duk_regconst_t reg_temp; reg_temp = DUK__ALLOCTEMP(comp_ctx); if (reg_varbind >= 0) { duk_regconst_t reg_res; duk_regconst_t reg_src; duk_int_t pc_temp_load; duk_int_t pc_before_rhs; duk_int_t pc_after_rhs; if (toplevel_assign) { /* 'reg_varbind' is the operation result and can also * become the expression value for top level assignments * such as: "var x; x += y;". */ DUK_DD(DUK_DDPRINT("= expression is top level, write directly to reg_varbind")); reg_res = reg_varbind; } else { /* Not safe to use 'reg_varbind' as assignment expression * value, so go through a temp. */ DUK_DD(DUK_DDPRINT("= expression is not top level, write to reg_temp")); reg_res = reg_temp; /* reg_res should be smallest possible */ reg_temp = DUK__ALLOCTEMP(comp_ctx); } /* Try to optimize X = Y for reg-bound * variables. Detect side-effect free RHS * narrowly by seeing whether it emits code. * If not, rewind the code emitter and overwrite * the unnecessary temp reg load. */ pc_temp_load = duk__get_current_pc(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_LDREG, reg_temp, reg_varbind); pc_before_rhs = duk__get_current_pc(comp_ctx); duk__expr_toregconst(comp_ctx, res, args_rbp /*rbp_flags*/); DUK_ASSERT(res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_REGCONST); pc_after_rhs = duk__get_current_pc(comp_ctx); DUK_DD(DUK_DDPRINT("pc_temp_load=%ld, pc_before_rhs=%ld, pc_after_rhs=%ld", (long) pc_temp_load, (long) pc_before_rhs, (long) pc_after_rhs)); if (pc_after_rhs == pc_before_rhs) { /* Note: if the reg_temp load generated shuffling * instructions, we may need to rewind more than * one instruction, so use explicit PC computation. */ DUK_DD(DUK_DDPRINT("rhs is side effect free, rewind and avoid unnecessary temp for reg-based =")); DUK_BW_ADD_PTR(comp_ctx->thr, &comp_ctx->curr_func.bw_code, (pc_temp_load - pc_before_rhs) * (duk_int_t) sizeof(duk_compiler_instr)); reg_src = reg_varbind; } else { DUK_DD(DUK_DDPRINT("rhs evaluation emitted code, not sure if rhs is side effect free; use temp reg for LHS")); reg_src = reg_temp; } duk__emit_a_b_c(comp_ctx, args_op | DUK__EMIT_FLAG_BC_REGCONST, reg_res, reg_src, res->x1.regconst); res->x1.regconst = reg_res; /* Ensure compact use of temps. */ if (DUK__ISREG_TEMP(comp_ctx, reg_res)) { DUK__SETTEMP(comp_ctx, reg_res + 1); } } else { /* When LHS is not register bound, always go through a * temporary. No optimization for top level assignment. */ duk__emit_a_bc(comp_ctx, DUK_OP_GETVAR, reg_temp, rc_varname); duk__expr_toregconst(comp_ctx, res, args_rbp /*rbp_flags*/); DUK_ASSERT(res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_REGCONST); duk__emit_a_b_c(comp_ctx, args_op | DUK__EMIT_FLAG_BC_REGCONST, reg_temp, reg_temp, res->x1.regconst); res->x1.regconst = reg_temp; } DUK_ASSERT(res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_REGCONST); } /* At this point 'res' holds the potential expression value. * It can be basically any ivalue here, including a reg-bound * identifier (if code above deems it safe) or a unary/binary * operation. Operations must be resolved to a side effect free * plain value, and the side effects must happen exactly once. */ if (reg_varbind >= 0) { if (res->t != DUK_IVAL_PLAIN) { /* Resolve 'res' directly into the LHS binding, and use * that as the expression value if safe. If not safe, * resolve to a temp/const and copy to LHS. */ if (toplevel_assign) { duk__ivalue_toforcedreg(comp_ctx, res, (duk_int_t) reg_varbind); } else { duk__ivalue_totempconst(comp_ctx, res); duk__copy_ivalue(comp_ctx, res, left); /* use 'left' as a temp */ duk__ivalue_toforcedreg(comp_ctx, left, (duk_int_t) reg_varbind); } } else { /* Use 'res' as the expression value (it's side effect * free and may be a plain value, a register, or a * constant) and write it to the LHS binding too. */ duk__copy_ivalue(comp_ctx, res, left); /* use 'left' as a temp */ duk__ivalue_toforcedreg(comp_ctx, left, (duk_int_t) reg_varbind); } } else { /* Only a reg fits into 'A' so coerce 'res' into a register * for PUTVAR. * * XXX: here the current A/B/C split is suboptimal: we could * just use 9 bits for reg_res (and support constants) and 17 * instead of 18 bits for the varname const index. */ duk__ivalue_toreg(comp_ctx, res); duk__emit_a_bc(comp_ctx, DUK_OP_PUTVAR | DUK__EMIT_FLAG_A_IS_SOURCE, res->x1.regconst, rc_varname); } /* 'res' contains expression value */ } else if (left->t == DUK_IVAL_PROP) { /* E5 Section 11.13.1 (and others) step 4 never matches for prop writes -> no check */ duk_regconst_t reg_obj; duk_regconst_t rc_key; duk_regconst_t rc_res; duk_regconst_t reg_temp; /* Property access expressions ('a[b]') are critical to correct * LHS evaluation ordering, see test-dev-assign-eval-order*.js. * We must make sure that the LHS target slot (base object and * key) don't change during RHS evaluation. The only concrete * problem is a register reference to a variable-bound register * (i.e., non-temp). Require temp regs for both key and base. * * Don't allow a constant for the object (even for a number * etc), as it goes into the 'A' field of the opcode. */ reg_obj = duk__ispec_toregconst_raw(comp_ctx, &left->x1, -1 /*forced_reg*/, DUK__IVAL_FLAG_REQUIRE_TEMP /*flags*/); rc_key = duk__ispec_toregconst_raw(comp_ctx, &left->x2, -1 /*forced_reg*/, DUK__IVAL_FLAG_REQUIRE_TEMP | DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); /* Evaluate RHS only when LHS is safe. */ if (args_op == DUK_OP_NONE) { duk__expr_toregconst(comp_ctx, res, args_rbp /*rbp_flags*/); DUK_ASSERT(res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_REGCONST); rc_res = res->x1.regconst; } else { reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__emit_a_b_c(comp_ctx, DUK_OP_GETPROP | DUK__EMIT_FLAG_BC_REGCONST, reg_temp, reg_obj, rc_key); duk__expr_toregconst(comp_ctx, res, args_rbp /*rbp_flags*/); DUK_ASSERT(res->t == DUK_IVAL_PLAIN && res->x1.t == DUK_ISPEC_REGCONST); duk__emit_a_b_c(comp_ctx, args_op | DUK__EMIT_FLAG_BC_REGCONST, reg_temp, reg_temp, res->x1.regconst); rc_res = reg_temp; } duk__emit_a_b_c(comp_ctx, DUK_OP_PUTPROP | DUK__EMIT_FLAG_A_IS_SOURCE | DUK__EMIT_FLAG_BC_REGCONST, reg_obj, rc_key, rc_res); duk__ivalue_regconst(res, rc_res); } else { /* No support for lvalues returned from new or function call expressions. * However, these must NOT cause compile-time SyntaxErrors, but run-time * ReferenceErrors. Both left and right sides of the assignment must be * evaluated before throwing a ReferenceError. For instance: * * f() = g(); * * must result in f() being evaluated, then g() being evaluated, and * finally, a ReferenceError being thrown. See E5 Section 11.13.1. */ duk_regconst_t rc_res; /* First evaluate LHS fully to ensure all side effects are out. */ duk__ivalue_toplain_ignore(comp_ctx, left); /* Then evaluate RHS fully (its value becomes the expression value too). * Technically we'd need the side effect safety check here too, but because * we always throw using INVLHS the result doesn't matter. */ rc_res = duk__expr_toregconst(comp_ctx, res, args_rbp /*rbp_flags*/); duk__emit_op_only(comp_ctx, DUK_OP_INVLHS); duk__ivalue_regconst(res, rc_res); } return; } postincdec: { /* * Post-increment/decrement will return the original value as its * result value. However, even that value will be coerced using * ToNumber() which is quite awkward. Specific bytecode opcodes * are used to handle these semantics. * * Note that post increment/decrement has a "no LineTerminator here" * restriction. This is handled by duk__expr_lbp(), which forcibly terminates * the previous expression if a LineTerminator occurs before '++'/'--'. */ duk_regconst_t reg_res; duk_small_uint_t args_op1 = (args >> 8) & 0xff; /* DUK_OP_POSTINCR/DUK_OP_POSTDECR */ duk_small_uint_t args_op2 = args >> 16; /* DUK_OP_POSTINCP_RR/DUK_OP_POSTDECP_RR */ /* Specific assumptions for opcode numbering. */ DUK_ASSERT(DUK_OP_POSTINCR + 4 == DUK_OP_POSTINCV); DUK_ASSERT(DUK_OP_POSTDECR + 4 == DUK_OP_POSTDECV); reg_res = DUK__ALLOCTEMP(comp_ctx); if (left->t == DUK_IVAL_VAR) { duk_hstring *h_varname; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; h_varname = duk_known_hstring(thr, left->x1.valstack_idx); if (duk__hstring_is_eval_or_arguments_in_strict_mode(comp_ctx, h_varname)) { goto syntax_error; } duk_dup(thr, left->x1.valstack_idx); if (duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { duk__emit_a_bc(comp_ctx, args_op1, /* e.g. DUK_OP_POSTINCR */ reg_res, reg_varbind); } else { duk__emit_a_bc(comp_ctx, args_op1 + 4, /* e.g. DUK_OP_POSTINCV */ reg_res, rc_varname); } DUK_DDD(DUK_DDDPRINT("postincdec to '%!O' -> reg_varbind=%ld, rc_varname=%ld", (duk_heaphdr *) h_varname, (long) reg_varbind, (long) rc_varname)); } else if (left->t == DUK_IVAL_PROP) { duk_regconst_t reg_obj; /* allocate to reg only (not const) */ duk_regconst_t rc_key; reg_obj = duk__ispec_toregconst_raw(comp_ctx, &left->x1, -1 /*forced_reg*/, 0 /*flags*/); /* don't allow const */ rc_key = duk__ispec_toregconst_raw(comp_ctx, &left->x2, -1 /*forced_reg*/, DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); duk__emit_a_b_c(comp_ctx, args_op2 | DUK__EMIT_FLAG_BC_REGCONST, /* e.g. DUK_OP_POSTINCP */ reg_res, reg_obj, rc_key); } else { /* Technically return value is not needed because INVLHS will * unconditially throw a ReferenceError. Coercion is necessary * for proper semantics (consider ToNumber() called for an object). * Use DUK_OP_UNP with a dummy register to get ToNumber(). */ duk__ivalue_toforcedreg(comp_ctx, left, reg_res); duk__emit_bc(comp_ctx, DUK_OP_UNP, reg_res); /* for side effects, result ignored */ duk__emit_op_only(comp_ctx, DUK_OP_INVLHS); } DUK__SETTEMP(comp_ctx, reg_res + 1); duk__ivalue_regconst(res, reg_res); return; } syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_EXPRESSION); DUK_WO_NORETURN(return;); syntax_error_lvalue: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_LVALUE); DUK_WO_NORETURN(return;); } DUK_LOCAL duk_small_uint_t duk__expr_lbp(duk_compiler_ctx *comp_ctx) { duk_small_uint_t tok = comp_ctx->curr_token.t; DUK_ASSERT_DISABLE(tok >= DUK_TOK_MINVAL); /* unsigned */ DUK_ASSERT(tok <= DUK_TOK_MAXVAL); DUK_ASSERT(sizeof(duk__token_lbp) == DUK_TOK_MAXVAL + 1); /* XXX: integrate support for this into led() instead? * Similar issue as post-increment/post-decrement. */ /* prevent duk__expr_led() by using a binding power less than anything valid */ if (tok == DUK_TOK_IN && !comp_ctx->curr_func.allow_in) { return 0; } if ((tok == DUK_TOK_DECREMENT || tok == DUK_TOK_INCREMENT) && (comp_ctx->curr_token.lineterm)) { /* '++' or '--' in a post-increment/decrement position, * and a LineTerminator occurs between the operator and * the preceding expression. Force the previous expr * to terminate, in effect treating e.g. "a,b\n++" as * "a,b;++" (= SyntaxError). */ return 0; } return DUK__TOKEN_LBP_GET_BP(duk__token_lbp[tok]); /* format is bit packed */ } /* * Expression parsing. * * Upon entry to 'expr' and its variants, 'curr_tok' is assumed to be the * first token of the expression. Upon exit, 'curr_tok' will be the first * token not part of the expression (e.g. semicolon terminating an expression * statement). */ #define DUK__EXPR_RBP_MASK 0xff #define DUK__EXPR_FLAG_REJECT_IN (1 << 8) /* reject 'in' token (used for for-in) */ #define DUK__EXPR_FLAG_ALLOW_EMPTY (1 << 9) /* allow empty expression */ #define DUK__EXPR_FLAG_REQUIRE_INIT (1 << 10) /* require initializer for var/const */ /* main expression parser function */ DUK_LOCAL void duk__expr(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk_hthread *thr = comp_ctx->thr; duk_ivalue tmp_alloc; /* 'res' is used for "left", and 'tmp' for "right" */ duk_ivalue *tmp = &tmp_alloc; duk_small_uint_t rbp; DUK__RECURSION_INCREASE(comp_ctx, thr); duk_require_stack(thr, DUK__PARSE_EXPR_SLOTS); /* filter out flags from exprtop rbp_flags here to save space */ rbp = rbp_flags & DUK__EXPR_RBP_MASK; DUK_DDD(DUK_DDDPRINT("duk__expr(), rbp_flags=%ld, rbp=%ld, allow_in=%ld, paren_level=%ld", (long) rbp_flags, (long) rbp, (long) comp_ctx->curr_func.allow_in, (long) comp_ctx->curr_func.paren_level)); duk_memzero(&tmp_alloc, sizeof(tmp_alloc)); tmp->x1.valstack_idx = duk_get_top(thr); tmp->x2.valstack_idx = tmp->x1.valstack_idx + 1; duk_push_undefined(thr); duk_push_undefined(thr); /* XXX: where to release temp regs in intermediate expressions? * e.g. 1+2+3 -> don't inflate temp register count when parsing this. * that particular expression temp regs can be forced here. */ /* XXX: increase ctx->expr_tokens here for every consumed token * (this would be a nice statistic)? */ if (comp_ctx->curr_token.t == DUK_TOK_SEMICOLON || comp_ctx->curr_token.t == DUK_TOK_RPAREN) { /* XXX: possibly incorrect handling of empty expression */ DUK_DDD(DUK_DDDPRINT("empty expression")); if (!(rbp_flags & DUK__EXPR_FLAG_ALLOW_EMPTY)) { DUK_ERROR_SYNTAX(thr, DUK_STR_EMPTY_EXPR_NOT_ALLOWED); DUK_WO_NORETURN(return;); } duk_push_undefined(thr); duk__ivalue_plain_fromstack(comp_ctx, res); goto cleanup; } duk__advance(comp_ctx); duk__expr_nud(comp_ctx, res); /* reuse 'res' as 'left' */ while (rbp < duk__expr_lbp(comp_ctx)) { duk__advance(comp_ctx); duk__expr_led(comp_ctx, res, tmp); duk__copy_ivalue(comp_ctx, tmp, res); /* tmp -> res */ } cleanup: /* final result is already in 'res' */ duk_pop_2(thr); DUK__RECURSION_DECREASE(comp_ctx, thr); } DUK_LOCAL void duk__exprtop(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk_hthread *thr = comp_ctx->thr; /* Note: these variables must reside in 'curr_func' instead of the global * context: when parsing function expressions, expression parsing is nested. */ comp_ctx->curr_func.nud_count = 0; comp_ctx->curr_func.led_count = 0; comp_ctx->curr_func.paren_level = 0; comp_ctx->curr_func.expr_lhs = 1; comp_ctx->curr_func.allow_in = (rbp_flags & DUK__EXPR_FLAG_REJECT_IN ? 0 : 1); duk__expr(comp_ctx, res, rbp_flags); if (!(rbp_flags & DUK__EXPR_FLAG_ALLOW_EMPTY) && duk__expr_is_empty(comp_ctx)) { DUK_ERROR_SYNTAX(thr, DUK_STR_EMPTY_EXPR_NOT_ALLOWED); DUK_WO_NORETURN(return;); } } /* A bunch of helpers (for size optimization) that combine duk__expr()/duk__exprtop() * and result conversions. * * Each helper needs at least 2-3 calls to make it worth while to wrap. */ #if 0 /* unused */ DUK_LOCAL duk_regconst_t duk__expr_toreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__expr(comp_ctx, res, rbp_flags); return duk__ivalue_toreg(comp_ctx, res); } #endif #if 0 /* unused */ DUK_LOCAL duk_regconst_t duk__expr_totemp(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__expr(comp_ctx, res, rbp_flags); return duk__ivalue_totemp(comp_ctx, res); } #endif DUK_LOCAL void duk__expr_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags, duk_regconst_t forced_reg) { DUK_ASSERT(forced_reg >= 0); duk__expr(comp_ctx, res, rbp_flags); duk__ivalue_toforcedreg(comp_ctx, res, forced_reg); } DUK_LOCAL duk_regconst_t duk__expr_toregconst(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__expr(comp_ctx, res, rbp_flags); return duk__ivalue_toregconst(comp_ctx, res); } #if 0 /* unused */ DUK_LOCAL duk_regconst_t duk__expr_totempconst(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__expr(comp_ctx, res, rbp_flags); return duk__ivalue_totempconst(comp_ctx, res); } #endif DUK_LOCAL void duk__expr_toplain(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__expr(comp_ctx, res, rbp_flags); duk__ivalue_toplain(comp_ctx, res); } DUK_LOCAL void duk__expr_toplain_ignore(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__expr(comp_ctx, res, rbp_flags); duk__ivalue_toplain_ignore(comp_ctx, res); } DUK_LOCAL duk_regconst_t duk__exprtop_toreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__exprtop(comp_ctx, res, rbp_flags); return duk__ivalue_toreg(comp_ctx, res); } #if 0 /* unused */ DUK_LOCAL duk_regconst_t duk__exprtop_totemp(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__exprtop(comp_ctx, res, rbp_flags); return duk__ivalue_totemp(comp_ctx, res); } #endif DUK_LOCAL void duk__exprtop_toforcedreg(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags, duk_regconst_t forced_reg) { DUK_ASSERT(forced_reg >= 0); duk__exprtop(comp_ctx, res, rbp_flags); duk__ivalue_toforcedreg(comp_ctx, res, forced_reg); } DUK_LOCAL duk_regconst_t duk__exprtop_toregconst(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t rbp_flags) { duk__exprtop(comp_ctx, res, rbp_flags); return duk__ivalue_toregconst(comp_ctx, res); } #if 0 /* unused */ DUK_LOCAL void duk__exprtop_toplain_ignore(duk_compiler_ctx *comp_ctx, duk_ivalue *res, int rbp_flags) { duk__exprtop(comp_ctx, res, rbp_flags); duk__ivalue_toplain_ignore(comp_ctx, res); } #endif /* * Parse an individual source element (top level statement) or a statement. * * Handles labeled statements automatically (peeling away labels before * parsing an expression that follows the label(s)). * * Upon entry, 'curr_tok' contains the first token of the statement (parsed * in "allow regexp literal" mode). Upon exit, 'curr_tok' contains the first * token following the statement (if the statement has a terminator, this is * the token after the terminator). */ #define DUK__HAS_VAL (1 << 0) /* stmt has non-empty value */ #define DUK__HAS_TERM (1 << 1) /* stmt has explicit/implicit semicolon terminator */ #define DUK__ALLOW_AUTO_SEMI_ALWAYS (1 << 2) /* allow automatic semicolon even without lineterm (compatibility) */ #define DUK__STILL_PROLOGUE (1 << 3) /* statement does not terminate directive prologue */ #define DUK__IS_TERMINAL (1 << 4) /* statement is guaranteed to be terminal (control doesn't flow to next statement) */ /* Parse a single variable declaration (e.g. "i" or "i=10"). A leading 'var' * has already been eaten. These is no return value in 'res', it is used only * as a temporary. * * When called from 'for-in' statement parser, the initializer expression must * not allow the 'in' token. The caller supply additional expression parsing * flags (like DUK__EXPR_FLAG_REJECT_IN) in 'expr_flags'. * * Finally, out_rc_varname and out_reg_varbind are updated to reflect where * the identifier is bound: * * If register bound: out_reg_varbind >= 0, out_rc_varname == 0 (ignore) * If not register bound: out_reg_varbind < 0, out_rc_varname >= 0 * * These allow the caller to use the variable for further assignment, e.g. * as is done in 'for-in' parsing. */ DUK_LOCAL void duk__parse_var_decl(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t expr_flags, duk_regconst_t *out_reg_varbind, duk_regconst_t *out_rc_varname) { duk_hthread *thr = comp_ctx->thr; duk_hstring *h_varname; duk_regconst_t reg_varbind; duk_regconst_t rc_varname; /* assume 'var' has been eaten */ /* Note: Identifier rejects reserved words */ if (comp_ctx->curr_token.t != DUK_TOK_IDENTIFIER) { goto syntax_error; } h_varname = comp_ctx->curr_token.str1; DUK_ASSERT(h_varname != NULL); /* strict mode restrictions (E5 Section 12.2.1) */ if (duk__hstring_is_eval_or_arguments_in_strict_mode(comp_ctx, h_varname)) { goto syntax_error; } /* register declarations in first pass */ if (comp_ctx->curr_func.in_scanning) { duk_uarridx_t n; DUK_DDD(DUK_DDDPRINT("register variable declaration %!O in pass 1", (duk_heaphdr *) h_varname)); n = (duk_uarridx_t) duk_get_length(thr, comp_ctx->curr_func.decls_idx); duk_push_hstring(thr, h_varname); duk_put_prop_index(thr, comp_ctx->curr_func.decls_idx, n); duk_push_int(thr, DUK_DECL_TYPE_VAR + (0 << 8)); duk_put_prop_index(thr, comp_ctx->curr_func.decls_idx, n + 1); } duk_push_hstring(thr, h_varname); /* push before advancing to keep reachable */ /* register binding lookup is based on varmap (even in first pass) */ duk_dup_top(thr); (void) duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname); duk__advance(comp_ctx); /* eat identifier */ if (comp_ctx->curr_token.t == DUK_TOK_EQUALSIGN) { duk__advance(comp_ctx); DUK_DDD(DUK_DDDPRINT("vardecl, assign to '%!O' -> reg_varbind=%ld, rc_varname=%ld", (duk_heaphdr *) h_varname, (long) reg_varbind, (long) rc_varname)); duk__exprtop(comp_ctx, res, DUK__BP_COMMA | expr_flags /*rbp_flags*/); /* AssignmentExpression */ if (reg_varbind >= 0) { duk__ivalue_toforcedreg(comp_ctx, res, reg_varbind); } else { duk_regconst_t reg_val; reg_val = duk__ivalue_toreg(comp_ctx, res); duk__emit_a_bc(comp_ctx, DUK_OP_PUTVAR | DUK__EMIT_FLAG_A_IS_SOURCE, reg_val, rc_varname); } } else { if (expr_flags & DUK__EXPR_FLAG_REQUIRE_INIT) { /* Used for minimal 'const': initializer required. */ goto syntax_error; } } duk_pop(thr); /* pop varname */ *out_rc_varname = rc_varname; *out_reg_varbind = reg_varbind; return; syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_VAR_DECLARATION); DUK_WO_NORETURN(return;); } DUK_LOCAL void duk__parse_var_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_small_uint_t expr_flags) { duk_regconst_t reg_varbind; duk_regconst_t rc_varname; duk__advance(comp_ctx); /* eat 'var' */ for (;;) { /* rc_varname and reg_varbind are ignored here */ duk__parse_var_decl(comp_ctx, res, 0 | expr_flags, ®_varbind, &rc_varname); if (comp_ctx->curr_token.t != DUK_TOK_COMMA) { break; } duk__advance(comp_ctx); } } DUK_LOCAL void duk__parse_for_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site) { duk_hthread *thr = comp_ctx->thr; duk_int_t pc_v34_lhs; /* start variant 3/4 left-hand-side code (L1 in doc/compiler.rst example) */ duk_regconst_t temp_reset; /* knock back "next temp" to this whenever possible */ duk_regconst_t reg_temps; /* preallocated temporaries (2) for variants 3 and 4 */ DUK_DDD(DUK_DDDPRINT("start parsing a for/for-in statement")); /* Two temporaries are preallocated here for variants 3 and 4 which need * registers which are never clobbered by expressions in the loop * (concretely: for the enumerator object and the next enumerated value). * Variants 1 and 2 "release" these temps. */ reg_temps = DUK__ALLOCTEMPS(comp_ctx, 2); temp_reset = DUK__GETTEMP(comp_ctx); /* * For/for-in main variants are: * * 1. for (ExpressionNoIn_opt; Expression_opt; Expression_opt) Statement * 2. for (var VariableDeclarationNoIn; Expression_opt; Expression_opt) Statement * 3. for (LeftHandSideExpression in Expression) Statement * 4. for (var VariableDeclarationNoIn in Expression) Statement * * Parsing these without arbitrary lookahead or backtracking is relatively * tricky but we manage to do so for now. * * See doc/compiler.rst for a detailed discussion of control flow * issues, evaluation order issues, etc. */ duk__advance(comp_ctx); /* eat 'for' */ duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); DUK_DDD(DUK_DDDPRINT("detecting for/for-in loop variant, pc=%ld", (long) duk__get_current_pc(comp_ctx))); /* a label site has been emitted by duk__parse_stmt() automatically * (it will also emit the ENDLABEL). */ if (comp_ctx->curr_token.t == DUK_TOK_VAR) { /* * Variant 2 or 4 */ duk_regconst_t reg_varbind; /* variable binding register if register-bound (otherwise < 0) */ duk_regconst_t rc_varname; /* variable name reg/const, if variable not register-bound */ duk__advance(comp_ctx); /* eat 'var' */ duk__parse_var_decl(comp_ctx, res, DUK__EXPR_FLAG_REJECT_IN, ®_varbind, &rc_varname); DUK__SETTEMP(comp_ctx, temp_reset); if (comp_ctx->curr_token.t == DUK_TOK_IN) { /* * Variant 4 */ DUK_DDD(DUK_DDDPRINT("detected for variant 4: for (var VariableDeclarationNoIn in Expression) Statement")); pc_v34_lhs = duk__get_current_pc(comp_ctx); /* jump is inserted here */ if (reg_varbind >= 0) { duk__emit_a_bc(comp_ctx, DUK_OP_LDREG, reg_varbind, reg_temps + 0); } else { duk__emit_a_bc(comp_ctx, DUK_OP_PUTVAR | DUK__EMIT_FLAG_A_IS_SOURCE, reg_temps + 0, rc_varname); } goto parse_3_or_4; } else { /* * Variant 2 */ DUK_DDD(DUK_DDDPRINT("detected for variant 2: for (var VariableDeclarationNoIn; Expression_opt; Expression_opt) Statement")); for (;;) { /* more initializers */ if (comp_ctx->curr_token.t != DUK_TOK_COMMA) { break; } DUK_DDD(DUK_DDDPRINT("variant 2 has another variable initializer")); duk__advance(comp_ctx); /* eat comma */ duk__parse_var_decl(comp_ctx, res, DUK__EXPR_FLAG_REJECT_IN, ®_varbind, &rc_varname); } goto parse_1_or_2; } } else { /* * Variant 1 or 3 */ pc_v34_lhs = duk__get_current_pc(comp_ctx); /* jump is inserted here (variant 3) */ /* Note that duk__exprtop() here can clobber any reg above current temp_next, * so any loop variables (e.g. enumerator) must be "preallocated". */ /* don't coerce yet to a plain value (variant 3 needs special handling) */ duk__exprtop(comp_ctx, res, DUK__BP_FOR_EXPR | DUK__EXPR_FLAG_REJECT_IN | DUK__EXPR_FLAG_ALLOW_EMPTY /*rbp_flags*/); /* Expression */ if (comp_ctx->curr_token.t == DUK_TOK_IN) { /* * Variant 3 */ /* XXX: need to determine LHS type, and check that it is LHS compatible */ DUK_DDD(DUK_DDDPRINT("detected for variant 3: for (LeftHandSideExpression in Expression) Statement")); if (duk__expr_is_empty(comp_ctx)) { goto syntax_error; /* LeftHandSideExpression does not allow empty expression */ } if (res->t == DUK_IVAL_VAR) { duk_regconst_t reg_varbind; duk_regconst_t rc_varname; duk_dup(thr, res->x1.valstack_idx); if (duk__lookup_lhs(comp_ctx, ®_varbind, &rc_varname)) { duk__emit_a_bc(comp_ctx, DUK_OP_LDREG, reg_varbind, reg_temps + 0); } else { duk__emit_a_bc(comp_ctx, DUK_OP_PUTVAR | DUK__EMIT_FLAG_A_IS_SOURCE, reg_temps + 0, rc_varname); } } else if (res->t == DUK_IVAL_PROP) { /* Don't allow a constant for the object (even for a number etc), as * it goes into the 'A' field of the opcode. */ duk_regconst_t reg_obj; duk_regconst_t rc_key; reg_obj = duk__ispec_toregconst_raw(comp_ctx, &res->x1, -1 /*forced_reg*/, 0 /*flags*/); /* don't allow const */ rc_key = duk__ispec_toregconst_raw(comp_ctx, &res->x2, -1 /*forced_reg*/, DUK__IVAL_FLAG_ALLOW_CONST /*flags*/); duk__emit_a_b_c(comp_ctx, DUK_OP_PUTPROP | DUK__EMIT_FLAG_A_IS_SOURCE | DUK__EMIT_FLAG_BC_REGCONST, reg_obj, rc_key, reg_temps + 0); } else { duk__ivalue_toplain_ignore(comp_ctx, res); /* just in case */ duk__emit_op_only(comp_ctx, DUK_OP_INVLHS); } goto parse_3_or_4; } else { /* * Variant 1 */ DUK_DDD(DUK_DDDPRINT("detected for variant 1: for (ExpressionNoIn_opt; Expression_opt; Expression_opt) Statement")); duk__ivalue_toplain_ignore(comp_ctx, res); goto parse_1_or_2; } } parse_1_or_2: /* * Parse variant 1 or 2. The first part expression (which differs * in the variants) has already been parsed and its code emitted. * * reg_temps + 0: unused * reg_temps + 1: unused */ { duk_regconst_t rc_cond; duk_int_t pc_l1, pc_l2, pc_l3, pc_l4; duk_int_t pc_jumpto_l3, pc_jumpto_l4; duk_bool_t expr_c_empty; DUK_DDD(DUK_DDDPRINT("shared code for parsing variants 1 and 2")); /* "release" preallocated temps since we won't need them */ temp_reset = reg_temps + 0; DUK__SETTEMP(comp_ctx, temp_reset); duk__advance_expect(comp_ctx, DUK_TOK_SEMICOLON); pc_l1 = duk__get_current_pc(comp_ctx); duk__exprtop(comp_ctx, res, DUK__BP_FOR_EXPR | DUK__EXPR_FLAG_ALLOW_EMPTY /*rbp_flags*/); /* Expression_opt */ if (duk__expr_is_empty(comp_ctx)) { /* no need to coerce */ pc_jumpto_l3 = duk__emit_jump_empty(comp_ctx); /* to body */ pc_jumpto_l4 = -1; /* omitted */ } else { rc_cond = duk__ivalue_toregconst(comp_ctx, res); duk__emit_if_false_skip(comp_ctx, rc_cond); pc_jumpto_l3 = duk__emit_jump_empty(comp_ctx); /* to body */ pc_jumpto_l4 = duk__emit_jump_empty(comp_ctx); /* to exit */ } DUK__SETTEMP(comp_ctx, temp_reset); duk__advance_expect(comp_ctx, DUK_TOK_SEMICOLON); pc_l2 = duk__get_current_pc(comp_ctx); duk__exprtop(comp_ctx, res, DUK__BP_FOR_EXPR | DUK__EXPR_FLAG_ALLOW_EMPTY /*rbp_flags*/); /* Expression_opt */ if (duk__expr_is_empty(comp_ctx)) { /* no need to coerce */ expr_c_empty = 1; /* JUMP L1 omitted */ } else { duk__ivalue_toplain_ignore(comp_ctx, res); expr_c_empty = 0; duk__emit_jump(comp_ctx, pc_l1); } DUK__SETTEMP(comp_ctx, temp_reset); comp_ctx->curr_func.allow_regexp_in_adv = 1; duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* Allow RegExp as part of next stmt. */ pc_l3 = duk__get_current_pc(comp_ctx); duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); if (expr_c_empty) { duk__emit_jump(comp_ctx, pc_l1); } else { duk__emit_jump(comp_ctx, pc_l2); } /* temp reset is not necessary after duk__parse_stmt(), which already does it */ pc_l4 = duk__get_current_pc(comp_ctx); DUK_DDD(DUK_DDDPRINT("patching jumps: jumpto_l3: %ld->%ld, jumpto_l4: %ld->%ld, " "break: %ld->%ld, continue: %ld->%ld", (long) pc_jumpto_l3, (long) pc_l3, (long) pc_jumpto_l4, (long) pc_l4, (long) (pc_label_site + 1), (long) pc_l4, (long) (pc_label_site + 2), (long) pc_l2)); duk__patch_jump(comp_ctx, pc_jumpto_l3, pc_l3); duk__patch_jump(comp_ctx, pc_jumpto_l4, pc_l4); duk__patch_jump(comp_ctx, pc_label_site + 1, pc_l4); /* break jump */ duk__patch_jump(comp_ctx, pc_label_site + 2, expr_c_empty ? pc_l1 : pc_l2); /* continue jump */ } goto finished; parse_3_or_4: /* * Parse variant 3 or 4. * * For variant 3 (e.g. "for (A in C) D;") the code for A (except the * final property/variable write) has already been emitted. The first * instruction of that code is at pc_v34_lhs; a JUMP needs to be inserted * there to satisfy control flow needs. * * For variant 4, if the variable declaration had an initializer * (e.g. "for (var A = B in C) D;") the code for the assignment * (B) has already been emitted. * * Variables set before entering here: * * pc_v34_lhs: insert a "JUMP L2" here (see doc/compiler.rst example). * reg_temps + 0: iteration target value (written to LHS) * reg_temps + 1: enumerator object */ { duk_int_t pc_l1, pc_l2, pc_l3, pc_l4, pc_l5; duk_int_t pc_jumpto_l2, pc_jumpto_l3, pc_jumpto_l4, pc_jumpto_l5; duk_regconst_t reg_target; DUK_DDD(DUK_DDDPRINT("shared code for parsing variants 3 and 4, pc_v34_lhs=%ld", (long) pc_v34_lhs)); DUK__SETTEMP(comp_ctx, temp_reset); /* First we need to insert a jump in the middle of previously * emitted code to get the control flow right. No jumps can * cross the position where the jump is inserted. See doc/compiler.rst * for discussion on the intricacies of control flow and side effects * for variants 3 and 4. */ duk__insert_jump_entry(comp_ctx, pc_v34_lhs); pc_jumpto_l2 = pc_v34_lhs; /* inserted jump */ pc_l1 = pc_v34_lhs + 1; /* +1, right after inserted jump */ /* The code for writing reg_temps + 0 to the left hand side has already * been emitted. */ pc_jumpto_l3 = duk__emit_jump_empty(comp_ctx); /* -> loop body */ duk__advance(comp_ctx); /* eat 'in' */ /* Parse enumeration target and initialize enumerator. For 'null' and 'undefined', * INITENUM will creates a 'null' enumerator which works like an empty enumerator * (E5 Section 12.6.4, step 3). Note that INITENUM requires the value to be in a * register (constant not allowed). */ pc_l2 = duk__get_current_pc(comp_ctx); reg_target = duk__exprtop_toreg(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); /* Expression */ duk__emit_b_c(comp_ctx, DUK_OP_INITENUM | DUK__EMIT_FLAG_B_IS_TARGET, reg_temps + 1, reg_target); pc_jumpto_l4 = duk__emit_jump_empty(comp_ctx); DUK__SETTEMP(comp_ctx, temp_reset); comp_ctx->curr_func.allow_regexp_in_adv = 1; duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* Allow RegExp as part of next stmt. */ pc_l3 = duk__get_current_pc(comp_ctx); duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); /* temp reset is not necessary after duk__parse_stmt(), which already does it */ /* NEXTENUM needs a jump slot right after the main opcode. * We need the code emitter to reserve the slot: if there's * target shuffling, the target shuffle opcodes must happen * after the jump slot (for NEXTENUM the shuffle opcodes are * not needed if the enum is finished). */ pc_l4 = duk__get_current_pc(comp_ctx); duk__emit_b_c(comp_ctx, DUK_OP_NEXTENUM | DUK__EMIT_FLAG_B_IS_TARGET | DUK__EMIT_FLAG_RESERVE_JUMPSLOT, reg_temps + 0, reg_temps + 1); pc_jumpto_l5 = comp_ctx->emit_jumpslot_pc; /* NEXTENUM jump slot: executed when enum finished */ duk__emit_jump(comp_ctx, pc_l1); /* jump to next loop, using reg_v34_iter as iterated value */ pc_l5 = duk__get_current_pc(comp_ctx); /* XXX: since the enumerator may be a memory expensive object, * perhaps clear it explicitly here? If so, break jump must * go through this clearing operation. */ DUK_DDD(DUK_DDDPRINT("patching jumps: jumpto_l2: %ld->%ld, jumpto_l3: %ld->%ld, " "jumpto_l4: %ld->%ld, jumpto_l5: %ld->%ld, " "break: %ld->%ld, continue: %ld->%ld", (long) pc_jumpto_l2, (long) pc_l2, (long) pc_jumpto_l3, (long) pc_l3, (long) pc_jumpto_l4, (long) pc_l4, (long) pc_jumpto_l5, (long) pc_l5, (long) (pc_label_site + 1), (long) pc_l5, (long) (pc_label_site + 2), (long) pc_l4)); duk__patch_jump(comp_ctx, pc_jumpto_l2, pc_l2); duk__patch_jump(comp_ctx, pc_jumpto_l3, pc_l3); duk__patch_jump(comp_ctx, pc_jumpto_l4, pc_l4); duk__patch_jump(comp_ctx, pc_jumpto_l5, pc_l5); duk__patch_jump(comp_ctx, pc_label_site + 1, pc_l5); /* break jump */ duk__patch_jump(comp_ctx, pc_label_site + 2, pc_l4); /* continue jump */ } goto finished; finished: DUK_DDD(DUK_DDDPRINT("end parsing a for/for-in statement")); return; syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_FOR); DUK_WO_NORETURN(return;); } DUK_LOCAL void duk__parse_switch_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site) { duk_hthread *thr = comp_ctx->thr; duk_regconst_t temp_at_loop; duk_regconst_t rc_switch; /* reg/const for switch value */ duk_regconst_t rc_case; /* reg/const for case value */ duk_regconst_t reg_temp; /* general temp register */ duk_int_t pc_prevcase = -1; duk_int_t pc_prevstmt = -1; duk_int_t pc_default = -1; /* -1 == not set, -2 == pending (next statement list) */ /* Note: negative pc values are ignored when patching jumps, so no explicit checks needed */ /* * Switch is pretty complicated because of several conflicting concerns: * * - Want to generate code without an intermediate representation, * i.e., in one go * * - Case selectors are expressions, not values, and may thus e.g. throw * exceptions (which causes evaluation order concerns) * * - Evaluation semantics of case selectors and default clause need to be * carefully implemented to provide correct behavior even with case value * side effects * * - Fall through case and default clauses; avoiding dead JUMPs if case * ends with an unconditional jump (a break or a continue) * * - The same case value may occur multiple times, but evaluation rules * only process the first match before switching to a "propagation" mode * where case values are no longer evaluated * * See E5 Section 12.11. Also see doc/compiler.rst for compilation * discussion. */ duk__advance(comp_ctx); duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); rc_switch = duk__exprtop_toregconst(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* RegExp mode does not matter. */ duk__advance_expect(comp_ctx, DUK_TOK_LCURLY); DUK_DDD(DUK_DDDPRINT("switch value in register %ld", (long) rc_switch)); temp_at_loop = DUK__GETTEMP(comp_ctx); for (;;) { duk_int_t num_stmts; duk_small_uint_t tok; /* sufficient for keeping temp reg numbers in check */ DUK__SETTEMP(comp_ctx, temp_at_loop); if (comp_ctx->curr_token.t == DUK_TOK_RCURLY) { break; } /* * Parse a case or default clause. */ if (comp_ctx->curr_token.t == DUK_TOK_CASE) { /* * Case clause. * * Note: cannot use reg_case as a temp register (for SEQ target) * because it may be a constant. */ duk__patch_jump_here(comp_ctx, pc_prevcase); /* chain jumps for case * evaluation and checking */ duk__advance(comp_ctx); rc_case = duk__exprtop_toregconst(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); duk__advance_expect(comp_ctx, DUK_TOK_COLON); reg_temp = DUK__ALLOCTEMP(comp_ctx); duk__emit_a_b_c(comp_ctx, DUK_OP_SEQ | DUK__EMIT_FLAG_BC_REGCONST, reg_temp, rc_switch, rc_case); duk__emit_if_true_skip(comp_ctx, reg_temp); /* jump to next case clause */ pc_prevcase = duk__emit_jump_empty(comp_ctx); /* no match, next case */ /* statements go here (if any) on next loop */ } else if (comp_ctx->curr_token.t == DUK_TOK_DEFAULT) { /* * Default clause. */ if (pc_default >= 0) { goto syntax_error; } duk__advance(comp_ctx); duk__advance_expect(comp_ctx, DUK_TOK_COLON); /* Fix for https://github.com/svaarala/duktape/issues/155: * If 'default' is first clause (detected by pc_prevcase < 0) * we need to ensure we stay in the matching chain. */ if (pc_prevcase < 0) { DUK_DD(DUK_DDPRINT("default clause is first, emit prevcase jump")); pc_prevcase = duk__emit_jump_empty(comp_ctx); } /* default clause matches next statement list (if any) */ pc_default = -2; } else { /* Code is not accepted before the first case/default clause */ goto syntax_error; } /* * Parse code after the clause. Possible terminators are * 'case', 'default', and '}'. * * Note that there may be no code at all, not even an empty statement, * between case clauses. This must be handled just like an empty statement * (omitting seemingly pointless JUMPs), to avoid situations like * test-bug-case-fallthrough.js. */ num_stmts = 0; if (pc_default == -2) { pc_default = duk__get_current_pc(comp_ctx); } /* Note: this is correct even for default clause statements: * they participate in 'fall-through' behavior even if the * default clause is in the middle. */ duk__patch_jump_here(comp_ctx, pc_prevstmt); /* chain jumps for 'fall-through' * after a case matches. */ for (;;) { tok = comp_ctx->curr_token.t; if (tok == DUK_TOK_CASE || tok == DUK_TOK_DEFAULT || tok == DUK_TOK_RCURLY) { break; } num_stmts++; duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); } /* fall-through jump to next code of next case (backpatched) */ pc_prevstmt = duk__emit_jump_empty(comp_ctx); /* XXX: would be nice to omit this jump when the jump is not * reachable, at least in the obvious cases (such as the case * ending with a 'break'. * * Perhaps duk__parse_stmt() could provide some info on whether * the statement is a "dead end"? * * If implemented, just set pc_prevstmt to -1 when not needed. */ } DUK_ASSERT(comp_ctx->curr_token.t == DUK_TOK_RCURLY); comp_ctx->curr_func.allow_regexp_in_adv = 1; duk__advance(comp_ctx); /* Allow RegExp as part of next stmt. */ /* default case control flow patchup; note that if pc_prevcase < 0 * (i.e. no case clauses), control enters default case automatically. */ if (pc_default >= 0) { /* default case exists: go there if no case matches */ duk__patch_jump(comp_ctx, pc_prevcase, pc_default); } else { /* default case does not exist, or no statements present * after default case: finish case evaluation */ duk__patch_jump_here(comp_ctx, pc_prevcase); } /* fall-through control flow patchup; note that pc_prevstmt may be * < 0 (i.e. no case clauses), in which case this is a no-op. */ duk__patch_jump_here(comp_ctx, pc_prevstmt); /* continue jump not patched, an INVALID opcode remains there */ duk__patch_jump_here(comp_ctx, pc_label_site + 1); /* break jump */ /* Note: 'fast' breaks will jump to pc_label_site + 1, which will * then jump here. The double jump will be eliminated by a * peephole pass, resulting in an optimal jump here. The label * site jumps will remain in bytecode and will waste code size. */ return; syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_SWITCH); DUK_WO_NORETURN(return;); } DUK_LOCAL void duk__parse_if_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_regconst_t temp_reset; duk_regconst_t rc_cond; duk_int_t pc_jump_false; DUK_DDD(DUK_DDDPRINT("begin parsing if statement")); temp_reset = DUK__GETTEMP(comp_ctx); duk__advance(comp_ctx); /* eat 'if' */ duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); rc_cond = duk__exprtop_toregconst(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); duk__emit_if_true_skip(comp_ctx, rc_cond); pc_jump_false = duk__emit_jump_empty(comp_ctx); /* jump to end or else part */ DUK__SETTEMP(comp_ctx, temp_reset); comp_ctx->curr_func.allow_regexp_in_adv = 1; duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* Allow RegExp as part of next stmt. */ duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); /* The 'else' ambiguity is resolved by 'else' binding to the innermost * construct, so greedy matching is correct here. */ if (comp_ctx->curr_token.t == DUK_TOK_ELSE) { duk_int_t pc_jump_end; DUK_DDD(DUK_DDDPRINT("if has else part")); duk__advance(comp_ctx); pc_jump_end = duk__emit_jump_empty(comp_ctx); /* jump from true part to end */ duk__patch_jump_here(comp_ctx, pc_jump_false); duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); duk__patch_jump_here(comp_ctx, pc_jump_end); } else { DUK_DDD(DUK_DDDPRINT("if does not have else part")); duk__patch_jump_here(comp_ctx, pc_jump_false); } DUK_DDD(DUK_DDDPRINT("end parsing if statement")); } DUK_LOCAL void duk__parse_do_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site) { duk_regconst_t rc_cond; duk_int_t pc_start; DUK_DDD(DUK_DDDPRINT("begin parsing do statement")); duk__advance(comp_ctx); /* Eat 'do'; allow RegExp as part of next stmt. */ pc_start = duk__get_current_pc(comp_ctx); duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); duk__patch_jump_here(comp_ctx, pc_label_site + 2); /* continue jump */ duk__advance_expect(comp_ctx, DUK_TOK_WHILE); duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); rc_cond = duk__exprtop_toregconst(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); duk__emit_if_false_skip(comp_ctx, rc_cond); duk__emit_jump(comp_ctx, pc_start); /* no need to reset temps, as we're finished emitting code */ comp_ctx->curr_func.allow_regexp_in_adv = 1; /* Allow RegExp as part of next stmt. */ duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); duk__patch_jump_here(comp_ctx, pc_label_site + 1); /* break jump */ DUK_DDD(DUK_DDDPRINT("end parsing do statement")); } DUK_LOCAL void duk__parse_while_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_int_t pc_label_site) { duk_regconst_t temp_reset; duk_regconst_t rc_cond; duk_int_t pc_start; duk_int_t pc_jump_false; DUK_DDD(DUK_DDDPRINT("begin parsing while statement")); temp_reset = DUK__GETTEMP(comp_ctx); duk__advance(comp_ctx); /* eat 'while' */ duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); pc_start = duk__get_current_pc(comp_ctx); duk__patch_jump_here(comp_ctx, pc_label_site + 2); /* continue jump */ rc_cond = duk__exprtop_toregconst(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); duk__emit_if_true_skip(comp_ctx, rc_cond); pc_jump_false = duk__emit_jump_empty(comp_ctx); DUK__SETTEMP(comp_ctx, temp_reset); comp_ctx->curr_func.allow_regexp_in_adv = 1; duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* Allow RegExp as part of next stmt. */ duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); duk__emit_jump(comp_ctx, pc_start); duk__patch_jump_here(comp_ctx, pc_jump_false); duk__patch_jump_here(comp_ctx, pc_label_site + 1); /* break jump */ DUK_DDD(DUK_DDDPRINT("end parsing while statement")); } DUK_LOCAL void duk__parse_break_or_continue_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk_bool_t is_break = (comp_ctx->curr_token.t == DUK_TOK_BREAK); duk_int_t label_id; duk_int_t label_catch_depth; duk_int_t label_pc; /* points to LABEL; pc+1 = jump site for break; pc+2 = jump site for continue */ duk_bool_t label_is_closest; DUK_UNREF(res); duk__advance(comp_ctx); /* eat 'break' or 'continue' */ if (comp_ctx->curr_token.t == DUK_TOK_SEMICOLON || /* explicit semi follows */ comp_ctx->curr_token.lineterm || /* automatic semi will be inserted */ comp_ctx->curr_token.allow_auto_semi) { /* automatic semi will be inserted */ /* break/continue without label */ duk__lookup_active_label(comp_ctx, DUK_HTHREAD_STRING_EMPTY_STRING(thr), is_break, &label_id, &label_catch_depth, &label_pc, &label_is_closest); } else if (comp_ctx->curr_token.t == DUK_TOK_IDENTIFIER) { /* break/continue with label (label cannot be a reserved word, production is 'Identifier' */ DUK_ASSERT(comp_ctx->curr_token.str1 != NULL); duk__lookup_active_label(comp_ctx, comp_ctx->curr_token.str1, is_break, &label_id, &label_catch_depth, &label_pc, &label_is_closest); duk__advance(comp_ctx); } else { DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_BREAK_CONT_LABEL); DUK_WO_NORETURN(return;); } /* Use a fast break/continue when possible. A fast break/continue is * just a jump to the LABEL break/continue jump slot, which then jumps * to an appropriate place (for break, going through ENDLABEL correctly). * The peephole optimizer will optimize the jump to a direct one. */ if (label_catch_depth == comp_ctx->curr_func.catch_depth && label_is_closest) { DUK_DDD(DUK_DDDPRINT("break/continue: is_break=%ld, label_id=%ld, label_is_closest=%ld, " "label_catch_depth=%ld, catch_depth=%ld " "-> use fast variant (direct jump)", (long) is_break, (long) label_id, (long) label_is_closest, (long) label_catch_depth, (long) comp_ctx->curr_func.catch_depth)); duk__emit_jump(comp_ctx, label_pc + (is_break ? 1 : 2)); } else { DUK_DDD(DUK_DDDPRINT("break/continue: is_break=%ld, label_id=%ld, label_is_closest=%ld, " "label_catch_depth=%ld, catch_depth=%ld " "-> use slow variant (longjmp)", (long) is_break, (long) label_id, (long) label_is_closest, (long) label_catch_depth, (long) comp_ctx->curr_func.catch_depth)); duk__emit_bc(comp_ctx, is_break ? DUK_OP_BREAK : DUK_OP_CONTINUE, (duk_regconst_t) label_id); } } DUK_LOCAL void duk__parse_return_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk_regconst_t rc_val; duk__advance(comp_ctx); /* eat 'return' */ /* A 'return' statement is only allowed inside an actual function body, * not as part of eval or global code. */ if (!comp_ctx->curr_func.is_function) { DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_RETURN); DUK_WO_NORETURN(return;); } if (comp_ctx->curr_token.t == DUK_TOK_SEMICOLON || /* explicit semi follows */ comp_ctx->curr_token.lineterm || /* automatic semi will be inserted */ comp_ctx->curr_token.allow_auto_semi) { /* automatic semi will be inserted */ DUK_DDD(DUK_DDDPRINT("empty return value -> undefined")); duk__emit_op_only(comp_ctx, DUK_OP_RETUNDEF); } else { duk_int_t pc_before_expr; duk_int_t pc_after_expr; DUK_DDD(DUK_DDDPRINT("return with a value")); DUK_UNREF(pc_before_expr); DUK_UNREF(pc_after_expr); pc_before_expr = duk__get_current_pc(comp_ctx); rc_val = duk__exprtop_toregconst(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); pc_after_expr = duk__get_current_pc(comp_ctx); /* Tail call check: if last opcode emitted was CALL, and * the context allows it, add a tailcall flag to the CALL. * This doesn't guarantee that a tail call will be allowed at * runtime, so the RETURN must still be emitted. (Duktape * 0.10.0 avoided this and simulated a RETURN if a tail call * couldn't be used at runtime; but this didn't work * correctly with a thread yield/resume, see * test-bug-tailcall-thread-yield-resume.js for discussion.) * * In addition to the last opcode being CALL, we also need to * be sure that 'rc_val' is the result register of the CALL. * For instance, for the expression 'return 0, (function () * { return 1; }), 2' the last opcode emitted is CALL (no * bytecode is emitted for '2') but 'rc_val' indicates * constant '2'. Similarly if '2' is replaced by a register * bound variable, no opcodes are emitted but tail call would * be incorrect. * * This is tricky and easy to get wrong. It would be best to * track enough expression metadata to check that 'rc_val' came * from that last CALL instruction. We don't have that metadata * now, so we check that 'rc_val' is a temporary register result * (not a constant or a register bound variable). There should * be no way currently for 'rc_val' to be a temporary for an * expression following the CALL instruction without emitting * some opcodes following the CALL. This proxy check is used * below. * * See: test-bug-comma-expr-gh131.js. * * The non-standard 'caller' property disables tail calls * because they pose some special cases which haven't been * fixed yet. */ #if defined(DUK_USE_TAILCALL) if (comp_ctx->curr_func.catch_depth == 0 && /* no catchers */ pc_after_expr > pc_before_expr) { /* at least one opcode emitted */ duk_compiler_instr *instr; duk_instr_t ins; duk_small_uint_t op; instr = duk__get_instr_ptr(comp_ctx, pc_after_expr - 1); DUK_ASSERT(instr != NULL); ins = instr->ins; op = (duk_small_uint_t) DUK_DEC_OP(ins); if ((op & ~0x0fU) == DUK_OP_CALL0 && DUK__ISREG_TEMP(comp_ctx, rc_val) /* see above */) { DUK_DDD(DUK_DDDPRINT("return statement detected a tail call opportunity: " "catch depth is 0, duk__exprtop() emitted >= 1 instructions, " "and last instruction is a CALL " "-> change to TAILCALL")); ins |= DUK_ENC_OP(DUK_BC_CALL_FLAG_TAILCALL); instr->ins = ins; } } #endif /* DUK_USE_TAILCALL */ if (DUK__ISREG(rc_val)) { duk__emit_bc(comp_ctx, DUK_OP_RETREG, rc_val); } else { rc_val = DUK__REMOVECONST(rc_val); if (duk__const_needs_refcount(comp_ctx, rc_val)) { duk__emit_bc(comp_ctx, DUK_OP_RETCONST, rc_val); } else { duk__emit_bc(comp_ctx, DUK_OP_RETCONSTN, rc_val); } } } } DUK_LOCAL void duk__parse_throw_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_regconst_t reg_val; duk__advance(comp_ctx); /* eat 'throw' */ /* Unlike break/continue, throw statement does not allow an empty value. */ if (comp_ctx->curr_token.lineterm) { DUK_ERROR_SYNTAX(comp_ctx->thr, DUK_STR_INVALID_THROW); DUK_WO_NORETURN(return;); } reg_val = duk__exprtop_toreg(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); duk__emit_bc(comp_ctx, DUK_OP_THROW, reg_val); } DUK_LOCAL void duk__parse_try_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_hthread *thr = comp_ctx->thr; duk_regconst_t reg_catch; /* reg_catch+0 and reg_catch+1 are reserved for TRYCATCH */ duk_regconst_t rc_varname = 0; duk_small_uint_t trycatch_flags = 0; duk_int_t pc_ldconst = -1; duk_int_t pc_trycatch = -1; duk_int_t pc_catch = -1; duk_int_t pc_finally = -1; DUK_UNREF(res); /* * See the following documentation for discussion: * * doc/execution.rst: control flow details * * Try, catch, and finally "parts" are Blocks, not Statements, so * they must always be delimited by curly braces. This is unlike e.g. * the if statement, which accepts any Statement. This eliminates any * questions of matching parts of nested try statements. The Block * parsing is implemented inline here (instead of calling out). * * Finally part has a 'let scoped' variable, which requires a few kinks * here. */ comp_ctx->curr_func.catch_depth++; duk__advance(comp_ctx); /* eat 'try' */ reg_catch = DUK__ALLOCTEMPS(comp_ctx, 2); /* The target for this LDCONST may need output shuffling, but we assume * that 'pc_ldconst' will be the LDCONST that we can patch later. This * should be the case because there's no input shuffling. (If there's * no catch clause, this LDCONST will be replaced with a NOP.) */ pc_ldconst = duk__get_current_pc(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_LDCONST, reg_catch, 0 /*patched later*/); pc_trycatch = duk__get_current_pc(comp_ctx); duk__emit_invalid(comp_ctx); /* TRYCATCH, cannot emit now (not enough info) */ duk__emit_invalid(comp_ctx); /* jump for 'catch' case */ duk__emit_invalid(comp_ctx); /* jump for 'finally' case or end (if no finally) */ /* try part */ duk__advance_expect(comp_ctx, DUK_TOK_LCURLY); duk__parse_stmts(comp_ctx, 0 /*allow_source_elem*/, 0 /*expect_eof*/, 1 /*regexp_after*/); /* the DUK_TOK_RCURLY is eaten by duk__parse_stmts() */ duk__emit_op_only(comp_ctx, DUK_OP_ENDTRY); if (comp_ctx->curr_token.t == DUK_TOK_CATCH) { /* * The catch variable must be updated to reflect the new allocated * register for the duration of the catch clause. We need to store * and restore the original value for the varmap entry (if any). */ /* * Note: currently register bindings must be fixed for the entire * function. So, even though the catch variable is in a register * we know, we must use an explicit environment record and slow path * accesses to read/write the catch binding to make closures created * within the catch clause work correctly. This restriction should * be fixable (at least in common cases) later. * * See: test-bug-catch-binding-2.js. * * XXX: improve to get fast path access to most catch clauses. */ duk_hstring *h_var; duk_int_t varmap_value; /* for storing/restoring the varmap binding for catch variable */ DUK_DDD(DUK_DDDPRINT("stack top at start of catch clause: %ld", (long) duk_get_top(thr))); trycatch_flags |= DUK_BC_TRYCATCH_FLAG_HAVE_CATCH; pc_catch = duk__get_current_pc(comp_ctx); duk__advance(comp_ctx); duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); if (comp_ctx->curr_token.t != DUK_TOK_IDENTIFIER) { /* Identifier, i.e. don't allow reserved words */ goto syntax_error; } h_var = comp_ctx->curr_token.str1; DUK_ASSERT(h_var != NULL); duk_push_hstring(thr, h_var); /* keep in on valstack, use borrowed ref below */ if (comp_ctx->curr_func.is_strict && ((h_var == DUK_HTHREAD_STRING_EVAL(thr)) || (h_var == DUK_HTHREAD_STRING_LC_ARGUMENTS(thr)))) { DUK_DDD(DUK_DDDPRINT("catch identifier 'eval' or 'arguments' in strict mode -> SyntaxError")); goto syntax_error; } duk_dup_top(thr); rc_varname = duk__getconst(comp_ctx); DUK_DDD(DUK_DDDPRINT("catch clause, rc_varname=0x%08lx (%ld)", (unsigned long) rc_varname, (long) rc_varname)); duk__advance(comp_ctx); duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); duk__advance_expect(comp_ctx, DUK_TOK_LCURLY); DUK_DDD(DUK_DDDPRINT("varmap before modifying for catch clause: %!iT", (duk_tval *) duk_get_tval(thr, comp_ctx->curr_func.varmap_idx))); duk_dup_top(thr); duk_get_prop(thr, comp_ctx->curr_func.varmap_idx); if (duk_is_undefined(thr, -1)) { varmap_value = -2; } else if (duk_is_null(thr, -1)) { varmap_value = -1; } else { DUK_ASSERT(duk_is_number(thr, -1)); varmap_value = duk_get_int(thr, -1); DUK_ASSERT(varmap_value >= 0); } duk_pop(thr); #if 0 /* It'd be nice to do something like this - but it doesn't * work for closures created inside the catch clause. */ duk_dup_top(thr); duk_push_int(thr, (duk_int_t) (reg_catch + 0)); duk_put_prop(thr, comp_ctx->curr_func.varmap_idx); #endif duk_dup_top(thr); duk_push_null(thr); duk_put_prop(thr, comp_ctx->curr_func.varmap_idx); duk__emit_a_bc(comp_ctx, DUK_OP_PUTVAR | DUK__EMIT_FLAG_A_IS_SOURCE, reg_catch + 0 /*value*/, rc_varname /*varname*/); DUK_DDD(DUK_DDDPRINT("varmap before parsing catch clause: %!iT", (duk_tval *) duk_get_tval(thr, comp_ctx->curr_func.varmap_idx))); duk__parse_stmts(comp_ctx, 0 /*allow_source_elem*/, 0 /*expect_eof*/, 1 /*regexp_after*/); /* the DUK_TOK_RCURLY is eaten by duk__parse_stmts() */ if (varmap_value == -2) { /* not present */ duk_del_prop(thr, comp_ctx->curr_func.varmap_idx); } else { if (varmap_value == -1) { duk_push_null(thr); } else { DUK_ASSERT(varmap_value >= 0); duk_push_int(thr, varmap_value); } duk_put_prop(thr, comp_ctx->curr_func.varmap_idx); } /* varname is popped by above code */ DUK_DDD(DUK_DDDPRINT("varmap after restore catch clause: %!iT", (duk_tval *) duk_get_tval(thr, comp_ctx->curr_func.varmap_idx))); duk__emit_op_only(comp_ctx, DUK_OP_ENDCATCH); /* * XXX: for now, indicate that an expensive catch binding * declarative environment is always needed. If we don't * need it, we don't need the const_varname either. */ trycatch_flags |= DUK_BC_TRYCATCH_FLAG_CATCH_BINDING; DUK_DDD(DUK_DDDPRINT("stack top at end of catch clause: %ld", (long) duk_get_top(thr))); } if (comp_ctx->curr_token.t == DUK_TOK_FINALLY) { trycatch_flags |= DUK_BC_TRYCATCH_FLAG_HAVE_FINALLY; pc_finally = duk__get_current_pc(comp_ctx); duk__advance(comp_ctx); duk__advance_expect(comp_ctx, DUK_TOK_LCURLY); duk__parse_stmts(comp_ctx, 0 /*allow_source_elem*/, 0 /*expect_eof*/, 1 /*regexp_after*/); /* the DUK_TOK_RCURLY is eaten by duk__parse_stmts() */ duk__emit_abc(comp_ctx, DUK_OP_ENDFIN, reg_catch); /* rethrow */ } if (!(trycatch_flags & DUK_BC_TRYCATCH_FLAG_HAVE_CATCH) && !(trycatch_flags & DUK_BC_TRYCATCH_FLAG_HAVE_FINALLY)) { /* must have catch and/or finally */ goto syntax_error; } /* If there's no catch block, rc_varname will be 0 and duk__patch_trycatch() * will replace the LDCONST with a NOP. For any actual constant (including * constant 0) the DUK__CONST_MARKER flag will be set in rc_varname. */ duk__patch_trycatch(comp_ctx, pc_ldconst, pc_trycatch, reg_catch, rc_varname, trycatch_flags); if (trycatch_flags & DUK_BC_TRYCATCH_FLAG_HAVE_CATCH) { DUK_ASSERT(pc_catch >= 0); duk__patch_jump(comp_ctx, pc_trycatch + 1, pc_catch); } if (trycatch_flags & DUK_BC_TRYCATCH_FLAG_HAVE_FINALLY) { DUK_ASSERT(pc_finally >= 0); duk__patch_jump(comp_ctx, pc_trycatch + 2, pc_finally); } else { /* without finally, the second jump slot is used to jump to end of stmt */ duk__patch_jump_here(comp_ctx, pc_trycatch + 2); } comp_ctx->curr_func.catch_depth--; return; syntax_error: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_TRY); DUK_WO_NORETURN(return;); } DUK_LOCAL void duk__parse_with_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res) { duk_int_t pc_trycatch; duk_int_t pc_finished; duk_regconst_t reg_catch; duk_small_uint_t trycatch_flags; if (comp_ctx->curr_func.is_strict) { DUK_ERROR_SYNTAX(comp_ctx->thr, DUK_STR_WITH_IN_STRICT_MODE); DUK_WO_NORETURN(return;); } comp_ctx->curr_func.catch_depth++; duk__advance(comp_ctx); /* eat 'with' */ reg_catch = DUK__ALLOCTEMPS(comp_ctx, 2); duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); duk__exprtop_toforcedreg(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/, reg_catch); comp_ctx->curr_func.allow_regexp_in_adv = 1; duk__advance_expect(comp_ctx, DUK_TOK_RPAREN); /* Allow RegExp as part of next stmt. */ pc_trycatch = duk__get_current_pc(comp_ctx); trycatch_flags = DUK_BC_TRYCATCH_FLAG_WITH_BINDING; duk__emit_a_bc(comp_ctx, DUK_OP_TRYCATCH | DUK__EMIT_FLAG_NO_SHUFFLE_A, (duk_regconst_t) trycatch_flags /*a*/, reg_catch /*bc*/); duk__emit_invalid(comp_ctx); /* catch jump */ duk__emit_invalid(comp_ctx); /* finished jump */ duk__parse_stmt(comp_ctx, res, 0 /*allow_source_elem*/); duk__emit_op_only(comp_ctx, DUK_OP_ENDTRY); pc_finished = duk__get_current_pc(comp_ctx); duk__patch_jump(comp_ctx, pc_trycatch + 2, pc_finished); comp_ctx->curr_func.catch_depth--; } DUK_LOCAL duk_int_t duk__stmt_label_site(duk_compiler_ctx *comp_ctx, duk_int_t label_id) { /* if a site already exists, nop: max one label site per statement */ if (label_id >= 0) { return label_id; } label_id = comp_ctx->curr_func.label_next++; DUK_DDD(DUK_DDDPRINT("allocated new label id for label site: %ld", (long) label_id)); duk__emit_bc(comp_ctx, DUK_OP_LABEL, (duk_regconst_t) label_id); duk__emit_invalid(comp_ctx); duk__emit_invalid(comp_ctx); return label_id; } /* Parse a single statement. * * Creates a label site (with an empty label) automatically for iteration * statements. Also "peels off" any label statements for explicit labels. */ DUK_LOCAL void duk__parse_stmt(duk_compiler_ctx *comp_ctx, duk_ivalue *res, duk_bool_t allow_source_elem) { duk_hthread *thr = comp_ctx->thr; duk_bool_t dir_prol_at_entry; /* directive prologue status at entry */ duk_regconst_t temp_at_entry; duk_size_t labels_len_at_entry; duk_int_t pc_at_entry; /* assumed to also be PC of "LABEL" */ duk_int_t stmt_id; duk_small_uint_t stmt_flags = 0; duk_int_t label_id = -1; duk_small_uint_t tok; duk_bool_t test_func_decl; DUK__RECURSION_INCREASE(comp_ctx, thr); temp_at_entry = DUK__GETTEMP(comp_ctx); pc_at_entry = duk__get_current_pc(comp_ctx); labels_len_at_entry = duk_get_length(thr, comp_ctx->curr_func.labelnames_idx); stmt_id = comp_ctx->curr_func.stmt_next++; dir_prol_at_entry = comp_ctx->curr_func.in_directive_prologue; DUK_UNREF(stmt_id); DUK_DDD(DUK_DDDPRINT("parsing a statement, stmt_id=%ld, temp_at_entry=%ld, labels_len_at_entry=%ld, " "is_strict=%ld, in_directive_prologue=%ld, catch_depth=%ld", (long) stmt_id, (long) temp_at_entry, (long) labels_len_at_entry, (long) comp_ctx->curr_func.is_strict, (long) comp_ctx->curr_func.in_directive_prologue, (long) comp_ctx->curr_func.catch_depth)); /* The directive prologue flag is cleared by default so that it is * unset for any recursive statement parsing. It is only "revived" * if a directive is detected. (We could also make directives only * allowed if 'allow_source_elem' was true.) */ comp_ctx->curr_func.in_directive_prologue = 0; retry_parse: DUK_DDD(DUK_DDDPRINT("try stmt parse, stmt_id=%ld, label_id=%ld, allow_source_elem=%ld, catch_depth=%ld", (long) stmt_id, (long) label_id, (long) allow_source_elem, (long) comp_ctx->curr_func.catch_depth)); /* * Detect iteration statements; if encountered, establish an * empty label. */ tok = comp_ctx->curr_token.t; if (tok == DUK_TOK_FOR || tok == DUK_TOK_DO || tok == DUK_TOK_WHILE || tok == DUK_TOK_SWITCH) { DUK_DDD(DUK_DDDPRINT("iteration/switch statement -> add empty label")); label_id = duk__stmt_label_site(comp_ctx, label_id); duk__add_label(comp_ctx, DUK_HTHREAD_STRING_EMPTY_STRING(thr), pc_at_entry /*pc_label*/, label_id); } /* * Main switch for statement / source element type. */ switch (comp_ctx->curr_token.t) { case DUK_TOK_FUNCTION: { /* * Function declaration, function expression, or (non-standard) * function statement. * * The E5 specification only allows function declarations at * the top level (in "source elements"). An ExpressionStatement * is explicitly not allowed to begin with a "function" keyword * (E5 Section 12.4). Hence any non-error semantics for such * non-top-level statements are non-standard. Duktape semantics * for function statements are modelled after V8, see * test-dev-func-decl-outside-top.js. */ test_func_decl = allow_source_elem; #if defined(DUK_USE_NONSTD_FUNC_STMT) /* Lenient: allow function declarations outside top level in * non-strict mode but reject them in strict mode. */ test_func_decl = test_func_decl || !comp_ctx->curr_func.is_strict; #endif /* DUK_USE_NONSTD_FUNC_STMT */ /* Strict: never allow function declarations outside top level. */ if (test_func_decl) { /* FunctionDeclaration: not strictly a statement but handled as such. * * O(depth^2) parse count for inner functions is handled by recording a * lexer offset on the first compilation pass, so that the function can * be efficiently skipped on the second pass. This is encapsulated into * duk__parse_func_like_fnum(). */ duk_int_t fnum; #if defined(DUK_USE_ASSERTIONS) duk_idx_t top_before; #endif DUK_DDD(DUK_DDDPRINT("function declaration statement")); #if defined(DUK_USE_ASSERTIONS) top_before = duk_get_top(thr); #endif duk__advance(comp_ctx); /* eat 'function' */ fnum = duk__parse_func_like_fnum(comp_ctx, DUK__FUNC_FLAG_DECL | DUK__FUNC_FLAG_PUSHNAME_PASS1); /* The value stack convention here is a bit odd: the function * name is only pushed on pass 1 (in_scanning), and is needed * to process function declarations. */ if (comp_ctx->curr_func.in_scanning) { duk_uarridx_t n; #if defined(DUK_USE_ASSERTIONS) DUK_ASSERT(duk_get_top(thr) == top_before + 1); #endif DUK_DDD(DUK_DDDPRINT("register function declaration %!T in pass 1, fnum %ld", duk_get_tval(thr, -1), (long) fnum)); n = (duk_uarridx_t) duk_get_length(thr, comp_ctx->curr_func.decls_idx); /* funcname is at index -1 */ duk_put_prop_index(thr, comp_ctx->curr_func.decls_idx, n); duk_push_int(thr, (duk_int_t) (DUK_DECL_TYPE_FUNC + (fnum << 8))); duk_put_prop_index(thr, comp_ctx->curr_func.decls_idx, n + 1); } else { #if defined(DUK_USE_ASSERTIONS) DUK_ASSERT(duk_get_top(thr) == top_before); #endif } /* no statement value (unlike function expression) */ stmt_flags = 0; break; } else { DUK_ERROR_SYNTAX(thr, DUK_STR_FUNC_STMT_NOT_ALLOWED); DUK_WO_NORETURN(return;); } break; } case DUK_TOK_LCURLY: { DUK_DDD(DUK_DDDPRINT("block statement")); duk__advance(comp_ctx); duk__parse_stmts(comp_ctx, 0 /*allow_source_elem*/, 0 /*expect_eof*/, 1 /*regexp_after*/); /* the DUK_TOK_RCURLY is eaten by duk__parse_stmts() */ if (label_id >= 0) { duk__patch_jump_here(comp_ctx, pc_at_entry + 1); /* break jump */ } stmt_flags = 0; break; } case DUK_TOK_CONST: { DUK_DDD(DUK_DDDPRINT("constant declaration statement")); duk__parse_var_stmt(comp_ctx, res, DUK__EXPR_FLAG_REQUIRE_INIT /*expr_flags*/); stmt_flags = DUK__HAS_TERM; break; } case DUK_TOK_VAR: { DUK_DDD(DUK_DDDPRINT("variable declaration statement")); duk__parse_var_stmt(comp_ctx, res, 0 /*expr_flags*/); stmt_flags = DUK__HAS_TERM; break; } case DUK_TOK_SEMICOLON: { /* empty statement with an explicit semicolon */ DUK_DDD(DUK_DDDPRINT("empty statement")); stmt_flags = DUK__HAS_TERM; break; } case DUK_TOK_IF: { DUK_DDD(DUK_DDDPRINT("if statement")); duk__parse_if_stmt(comp_ctx, res); if (label_id >= 0) { duk__patch_jump_here(comp_ctx, pc_at_entry + 1); /* break jump */ } stmt_flags = 0; break; } case DUK_TOK_DO: { /* * Do-while statement is mostly trivial, but there is special * handling for automatic semicolon handling (triggered by the * DUK__ALLOW_AUTO_SEMI_ALWAYS) flag related to a bug filed at: * * https://bugs.ecmascript.org/show_bug.cgi?id=8 * * See doc/compiler.rst for details. */ DUK_DDD(DUK_DDDPRINT("do statement")); DUK_ASSERT(label_id >= 0); duk__update_label_flags(comp_ctx, label_id, DUK_LABEL_FLAG_ALLOW_BREAK | DUK_LABEL_FLAG_ALLOW_CONTINUE); duk__parse_do_stmt(comp_ctx, res, pc_at_entry); stmt_flags = DUK__HAS_TERM | DUK__ALLOW_AUTO_SEMI_ALWAYS; /* DUK__ALLOW_AUTO_SEMI_ALWAYS workaround */ break; } case DUK_TOK_WHILE: { DUK_DDD(DUK_DDDPRINT("while statement")); DUK_ASSERT(label_id >= 0); duk__update_label_flags(comp_ctx, label_id, DUK_LABEL_FLAG_ALLOW_BREAK | DUK_LABEL_FLAG_ALLOW_CONTINUE); duk__parse_while_stmt(comp_ctx, res, pc_at_entry); stmt_flags = 0; break; } case DUK_TOK_FOR: { /* * For/for-in statement is complicated to parse because * determining the statement type (three-part for vs. a * for-in) requires potential backtracking. * * See the helper for the messy stuff. */ DUK_DDD(DUK_DDDPRINT("for/for-in statement")); DUK_ASSERT(label_id >= 0); duk__update_label_flags(comp_ctx, label_id, DUK_LABEL_FLAG_ALLOW_BREAK | DUK_LABEL_FLAG_ALLOW_CONTINUE); duk__parse_for_stmt(comp_ctx, res, pc_at_entry); stmt_flags = 0; break; } case DUK_TOK_CONTINUE: case DUK_TOK_BREAK: { DUK_DDD(DUK_DDDPRINT("break/continue statement")); duk__parse_break_or_continue_stmt(comp_ctx, res); stmt_flags = DUK__HAS_TERM | DUK__IS_TERMINAL; break; } case DUK_TOK_RETURN: { DUK_DDD(DUK_DDDPRINT("return statement")); duk__parse_return_stmt(comp_ctx, res); stmt_flags = DUK__HAS_TERM | DUK__IS_TERMINAL; break; } case DUK_TOK_WITH: { DUK_DDD(DUK_DDDPRINT("with statement")); comp_ctx->curr_func.with_depth++; duk__parse_with_stmt(comp_ctx, res); if (label_id >= 0) { duk__patch_jump_here(comp_ctx, pc_at_entry + 1); /* break jump */ } comp_ctx->curr_func.with_depth--; stmt_flags = 0; break; } case DUK_TOK_SWITCH: { /* * The switch statement is pretty messy to compile. * See the helper for details. */ DUK_DDD(DUK_DDDPRINT("switch statement")); DUK_ASSERT(label_id >= 0); duk__update_label_flags(comp_ctx, label_id, DUK_LABEL_FLAG_ALLOW_BREAK); /* don't allow continue */ duk__parse_switch_stmt(comp_ctx, res, pc_at_entry); stmt_flags = 0; break; } case DUK_TOK_THROW: { DUK_DDD(DUK_DDDPRINT("throw statement")); duk__parse_throw_stmt(comp_ctx, res); stmt_flags = DUK__HAS_TERM | DUK__IS_TERMINAL; break; } case DUK_TOK_TRY: { DUK_DDD(DUK_DDDPRINT("try statement")); duk__parse_try_stmt(comp_ctx, res); stmt_flags = 0; break; } case DUK_TOK_DEBUGGER: { duk__advance(comp_ctx); #if defined(DUK_USE_DEBUGGER_SUPPORT) DUK_DDD(DUK_DDDPRINT("debugger statement: debugging enabled, emit debugger opcode")); duk__emit_op_only(comp_ctx, DUK_OP_DEBUGGER); #else DUK_DDD(DUK_DDDPRINT("debugger statement: ignored")); #endif stmt_flags = DUK__HAS_TERM; break; } default: { /* * Else, must be one of: * - ExpressionStatement, possibly a directive (String) * - LabelledStatement (Identifier followed by ':') * * Expressions beginning with 'function' keyword are covered by a case * above (such expressions are not allowed in standard E5 anyway). * Also expressions starting with '{' are interpreted as block * statements. See E5 Section 12.4. * * Directive detection is tricky; see E5 Section 14.1 on directive * prologue. A directive is an expression statement with a single * string literal and an explicit or automatic semicolon. Escape * characters are significant and no parens etc are allowed: * * 'use strict'; // valid 'use strict' directive * 'use\u0020strict'; // valid directive, not a 'use strict' directive * ('use strict'); // not a valid directive * * The expression is determined to consist of a single string literal * based on duk__expr_nud() and duk__expr_led() call counts. The string literal * of a 'use strict' directive is determined to lack any escapes based * num_escapes count from the lexer. Note that other directives may be * allowed to contain escapes, so a directive with escapes does not * terminate a directive prologue. * * We rely on the fact that the expression parser will not emit any * code for a single token expression. However, it will generate an * intermediate value which we will then successfully ignore. * * A similar approach is used for labels. */ duk_bool_t single_token; DUK_DDD(DUK_DDDPRINT("expression statement")); duk__exprtop(comp_ctx, res, DUK__BP_FOR_EXPR /*rbp_flags*/); single_token = (comp_ctx->curr_func.nud_count == 1 && /* one token */ comp_ctx->curr_func.led_count == 0); /* no operators */ if (single_token && comp_ctx->prev_token.t == DUK_TOK_IDENTIFIER && comp_ctx->curr_token.t == DUK_TOK_COLON) { /* * Detected label */ duk_hstring *h_lab; /* expected ival */ DUK_ASSERT(res->t == DUK_IVAL_VAR); DUK_ASSERT(res->x1.t == DUK_ISPEC_VALUE); DUK_ASSERT(DUK_TVAL_IS_STRING(duk_get_tval(thr, res->x1.valstack_idx))); h_lab = comp_ctx->prev_token.str1; DUK_ASSERT(h_lab != NULL); DUK_DDD(DUK_DDDPRINT("explicit label site for label '%!O'", (duk_heaphdr *) h_lab)); duk__advance(comp_ctx); /* eat colon */ label_id = duk__stmt_label_site(comp_ctx, label_id); duk__add_label(comp_ctx, h_lab, pc_at_entry /*pc_label*/, label_id); /* a statement following a label cannot be a source element * (a function declaration). */ allow_source_elem = 0; DUK_DDD(DUK_DDDPRINT("label handled, retry statement parsing")); goto retry_parse; } stmt_flags = 0; if (dir_prol_at_entry && /* still in prologue */ single_token && /* single string token */ comp_ctx->prev_token.t == DUK_TOK_STRING) { /* * Detected a directive */ duk_hstring *h_dir; /* expected ival */ DUK_ASSERT(res->t == DUK_IVAL_PLAIN); DUK_ASSERT(res->x1.t == DUK_ISPEC_VALUE); DUK_ASSERT(DUK_TVAL_IS_STRING(duk_get_tval(thr, res->x1.valstack_idx))); h_dir = comp_ctx->prev_token.str1; DUK_ASSERT(h_dir != NULL); DUK_DDD(DUK_DDDPRINT("potential directive: %!O", h_dir)); stmt_flags |= DUK__STILL_PROLOGUE; /* Note: escaped characters differentiate directives */ if (comp_ctx->prev_token.num_escapes > 0) { DUK_DDD(DUK_DDDPRINT("directive contains escapes: valid directive " "but we ignore such directives")); } else { /* * The length comparisons are present to handle * strings like "use strict\u0000foo" as required. */ if (DUK_HSTRING_GET_BYTELEN(h_dir) == 10 && DUK_STRCMP((const char *) DUK_HSTRING_GET_DATA(h_dir), "use strict") == 0) { #if defined(DUK_USE_STRICT_DECL) DUK_DDD(DUK_DDDPRINT("use strict directive detected: strict flag %ld -> %ld", (long) comp_ctx->curr_func.is_strict, (long) 1)); comp_ctx->curr_func.is_strict = 1; #else DUK_DDD(DUK_DDDPRINT("use strict detected but strict declarations disabled, ignoring")); #endif } else if (DUK_HSTRING_GET_BYTELEN(h_dir) == 14 && DUK_STRCMP((const char *) DUK_HSTRING_GET_DATA(h_dir), "use duk notail") == 0) { DUK_DDD(DUK_DDDPRINT("use duk notail directive detected: notail flag %ld -> %ld", (long) comp_ctx->curr_func.is_notail, (long) 1)); comp_ctx->curr_func.is_notail = 1; } else { DUK_DD(DUK_DDPRINT("unknown directive: '%!O', ignoring but not terminating " "directive prologue", (duk_hobject *) h_dir)); } } } else { DUK_DDD(DUK_DDDPRINT("non-directive expression statement or no longer in prologue; " "prologue terminated if still active")); } stmt_flags |= DUK__HAS_VAL | DUK__HAS_TERM; } } /* end switch (tok) */ /* * Statement value handling. * * Global code and eval code has an implicit return value * which comes from the last statement with a value * (technically a non-"empty" continuation, which is * different from an empty statement). * * Since we don't know whether a later statement will * override the value of the current statement, we need * to coerce the statement value to a register allocated * for implicit return values. In other cases we need * to coerce the statement value to a plain value to get * any side effects out (consider e.g. "foo.bar;"). */ /* XXX: what about statements which leave a half-cooked value in 'res' * but have no stmt value? Any such statements? */ if (stmt_flags & DUK__HAS_VAL) { duk_regconst_t reg_stmt_value = comp_ctx->curr_func.reg_stmt_value; if (reg_stmt_value >= 0) { duk__ivalue_toforcedreg(comp_ctx, res, reg_stmt_value); } else { duk__ivalue_toplain_ignore(comp_ctx, res); } } else { ; } /* * Statement terminator check, including automatic semicolon * handling. After this step, 'curr_tok' should be the first * token after a possible statement terminator. */ if (stmt_flags & DUK__HAS_TERM) { if (comp_ctx->curr_token.t == DUK_TOK_SEMICOLON) { DUK_DDD(DUK_DDDPRINT("explicit semicolon terminates statement")); duk__advance(comp_ctx); } else { if (comp_ctx->curr_token.allow_auto_semi) { DUK_DDD(DUK_DDDPRINT("automatic semicolon terminates statement")); } else if (stmt_flags & DUK__ALLOW_AUTO_SEMI_ALWAYS) { /* XXX: make this lenience dependent on flags or strictness? */ DUK_DDD(DUK_DDDPRINT("automatic semicolon terminates statement (allowed for compatibility " "even though no lineterm present before next token)")); } else { DUK_ERROR_SYNTAX(thr, DUK_STR_UNTERMINATED_STMT); DUK_WO_NORETURN(return;); } } } else { DUK_DDD(DUK_DDDPRINT("statement has no terminator")); } /* * Directive prologue tracking. */ if (stmt_flags & DUK__STILL_PROLOGUE) { DUK_DDD(DUK_DDDPRINT("setting in_directive_prologue")); comp_ctx->curr_func.in_directive_prologue = 1; } /* * Cleanups (all statement parsing flows through here). * * Pop label site and reset labels. Reset 'next temp' to value at * entry to reuse temps. */ if (label_id >= 0) { duk__emit_bc(comp_ctx, DUK_OP_ENDLABEL, (duk_regconst_t) label_id); } DUK__SETTEMP(comp_ctx, temp_at_entry); duk__reset_labels_to_length(comp_ctx, labels_len_at_entry); /* XXX: return indication of "terminalness" (e.g. a 'throw' is terminal) */ DUK__RECURSION_DECREASE(comp_ctx, thr); } /* * Parse a statement list. * * Handles automatic semicolon insertion and implicit return value. * * Upon entry, 'curr_tok' should contain the first token of the first * statement (parsed in the "allow regexp literal" mode). Upon exit, * 'curr_tok' contains the token following the statement list terminator * (EOF or closing brace). */ DUK_LOCAL void duk__parse_stmts(duk_compiler_ctx *comp_ctx, duk_bool_t allow_source_elem, duk_bool_t expect_eof, duk_bool_t regexp_after) { duk_hthread *thr = comp_ctx->thr; duk_ivalue res_alloc; duk_ivalue *res = &res_alloc; /* Setup state. Initial ivalue is 'undefined'. */ duk_require_stack(thr, DUK__PARSE_STATEMENTS_SLOTS); /* XXX: 'res' setup can be moved to function body level; in fact, two 'res' * intermediate values suffice for parsing of each function. Nesting is needed * for nested functions (which may occur inside expressions). */ duk_memzero(&res_alloc, sizeof(res_alloc)); res->t = DUK_IVAL_PLAIN; res->x1.t = DUK_ISPEC_VALUE; res->x1.valstack_idx = duk_get_top(thr); res->x2.valstack_idx = res->x1.valstack_idx + 1; duk_push_undefined(thr); duk_push_undefined(thr); /* Parse statements until a closing token (EOF or '}') is found. */ for (;;) { /* Check whether statement list ends. */ if (expect_eof) { if (comp_ctx->curr_token.t == DUK_TOK_EOF) { break; } } else { if (comp_ctx->curr_token.t == DUK_TOK_RCURLY) { break; } } /* Check statement type based on the first token type. * * Note: expression parsing helpers expect 'curr_tok' to * contain the first token of the expression upon entry. */ DUK_DDD(DUK_DDDPRINT("TOKEN %ld (non-whitespace, non-comment)", (long) comp_ctx->curr_token.t)); duk__parse_stmt(comp_ctx, res, allow_source_elem); } /* RegExp is allowed / not allowed depending on context. For function * declarations RegExp is allowed because it follows a function * declaration statement and may appear as part of the next statement. * For function expressions RegExp is not allowed, and it's possible * to do something like '(function () {} / 123)'. */ if (regexp_after) { comp_ctx->curr_func.allow_regexp_in_adv = 1; } duk__advance(comp_ctx); /* Tear down state. */ duk_pop_2(thr); } /* * Declaration binding instantiation conceptually happens when calling a * function; for us it essentially means that function prologue. The * conceptual process is described in E5 Section 10.5. * * We need to keep track of all encountered identifiers to (1) create an * identifier-to-register map ("varmap"); and (2) detect duplicate * declarations. Identifiers which are not bound to registers still need * to be tracked for detecting duplicates. Currently such identifiers * are put into the varmap with a 'null' value, which is later cleaned up. * * To support functions with a large number of variable and function * declarations, registers are not allocated beyond a certain limit; * after that limit, variables and functions need slow path access. * Arguments are currently always register bound, which imposes a hard * (and relatively small) argument count limit. * * Some bindings in E5 are not configurable (= deletable) and almost all * are mutable (writable). Exceptions are: * * - The 'arguments' binding, established only if no shadowing argument * or function declaration exists. We handle 'arguments' creation * and binding through an explicit slow path environment record. * * - The "name" binding for a named function expression. This is also * handled through an explicit slow path environment record. */ /* XXX: add support for variables to not be register bound always, to * handle cases with a very large number of variables? */ DUK_LOCAL void duk__init_varmap_and_prologue_for_pass2(duk_compiler_ctx *comp_ctx, duk_regconst_t *out_stmt_value_reg) { duk_hthread *thr = comp_ctx->thr; duk_hstring *h_name; duk_bool_t configurable_bindings; duk_uarridx_t num_args; duk_uarridx_t num_decls; duk_regconst_t rc_name; duk_small_uint_t declvar_flags; duk_uarridx_t i; #if defined(DUK_USE_ASSERTIONS) duk_idx_t entry_top; #endif #if defined(DUK_USE_ASSERTIONS) entry_top = duk_get_top(thr); #endif /* * Preliminaries */ configurable_bindings = comp_ctx->curr_func.is_eval; DUK_DDD(DUK_DDDPRINT("configurable_bindings=%ld", (long) configurable_bindings)); /* varmap is already in comp_ctx->curr_func.varmap_idx */ /* * Function formal arguments, always bound to registers * (there's no support for shuffling them now). */ num_args = (duk_uarridx_t) duk_get_length(thr, comp_ctx->curr_func.argnames_idx); DUK_DDD(DUK_DDDPRINT("num_args=%ld", (long) num_args)); /* XXX: check num_args */ for (i = 0; i < num_args; i++) { duk_get_prop_index(thr, comp_ctx->curr_func.argnames_idx, i); h_name = duk_known_hstring(thr, -1); if (comp_ctx->curr_func.is_strict) { if (duk__hstring_is_eval_or_arguments(comp_ctx, h_name)) { DUK_DDD(DUK_DDDPRINT("arg named 'eval' or 'arguments' in strict mode -> SyntaxError")); goto error_argname; } duk_dup_top(thr); if (duk_has_prop(thr, comp_ctx->curr_func.varmap_idx)) { DUK_DDD(DUK_DDDPRINT("duplicate arg name in strict mode -> SyntaxError")); goto error_argname; } /* Ensure argument name is not a reserved word in current * (final) strictness. Formal argument parsing may not * catch reserved names if strictness changes during * parsing. * * We only need to do this in strict mode because non-strict * keyword are always detected in formal argument parsing. */ if (DUK_HSTRING_HAS_STRICT_RESERVED_WORD(h_name)) { goto error_argname; } } /* overwrite any previous binding of the same name; the effect is * that last argument of a certain name wins. */ /* only functions can have arguments */ DUK_ASSERT(comp_ctx->curr_func.is_function); duk_push_uarridx(thr, i); /* -> [ ... name index ] */ duk_put_prop(thr, comp_ctx->curr_func.varmap_idx); /* -> [ ... ] */ /* no code needs to be emitted, the regs already have values */ } /* use temp_next for tracking register allocations */ DUK__SETTEMP_CHECKMAX(comp_ctx, (duk_regconst_t) num_args); /* * After arguments, allocate special registers (like shuffling temps) */ if (out_stmt_value_reg) { *out_stmt_value_reg = DUK__ALLOCTEMP(comp_ctx); } if (comp_ctx->curr_func.needs_shuffle) { duk_regconst_t shuffle_base = DUK__ALLOCTEMPS(comp_ctx, 3); comp_ctx->curr_func.shuffle1 = shuffle_base; comp_ctx->curr_func.shuffle2 = shuffle_base + 1; comp_ctx->curr_func.shuffle3 = shuffle_base + 2; DUK_D(DUK_DPRINT("shuffle registers needed by function, allocated: %ld %ld %ld", (long) comp_ctx->curr_func.shuffle1, (long) comp_ctx->curr_func.shuffle2, (long) comp_ctx->curr_func.shuffle3)); } if (comp_ctx->curr_func.temp_next > 0x100) { DUK_D(DUK_DPRINT("not enough 8-bit regs: temp_next=%ld", (long) comp_ctx->curr_func.temp_next)); goto error_outofregs; } /* * Function declarations */ num_decls = (duk_uarridx_t) duk_get_length(thr, comp_ctx->curr_func.decls_idx); DUK_DDD(DUK_DDDPRINT("num_decls=%ld -> %!T", (long) num_decls, (duk_tval *) duk_get_tval(thr, comp_ctx->curr_func.decls_idx))); for (i = 0; i < num_decls; i += 2) { duk_int_t decl_type; duk_int_t fnum; duk_get_prop_index(thr, comp_ctx->curr_func.decls_idx, i + 1); /* decl type */ decl_type = duk_to_int(thr, -1); fnum = decl_type >> 8; /* XXX: macros */ decl_type = decl_type & 0xff; duk_pop(thr); if (decl_type != DUK_DECL_TYPE_FUNC) { continue; } duk_get_prop_index(thr, comp_ctx->curr_func.decls_idx, i); /* decl name */ /* XXX: spilling */ if (comp_ctx->curr_func.is_function) { duk_regconst_t reg_bind; duk_dup_top(thr); if (duk_has_prop(thr, comp_ctx->curr_func.varmap_idx)) { /* shadowed; update value */ duk_dup_top(thr); duk_get_prop(thr, comp_ctx->curr_func.varmap_idx); reg_bind = duk_to_int(thr, -1); /* [ ... name reg_bind ] */ duk__emit_a_bc(comp_ctx, DUK_OP_CLOSURE, reg_bind, (duk_regconst_t) fnum); } else { /* function: always register bound */ reg_bind = DUK__ALLOCTEMP(comp_ctx); duk__emit_a_bc(comp_ctx, DUK_OP_CLOSURE, reg_bind, (duk_regconst_t) fnum); duk_push_int(thr, (duk_int_t) reg_bind); } } else { /* Function declaration for global/eval code is emitted even * for duplicates, because of E5 Section 10.5, step 5.e of * E5.1 (special behavior for variable bound to global object). * * DECLVAR will not re-declare a variable as such, but will * update the binding value. */ duk_regconst_t reg_temp = DUK__ALLOCTEMP(comp_ctx); duk_dup_top(thr); rc_name = duk__getconst(comp_ctx); duk_push_null(thr); duk__emit_a_bc(comp_ctx, DUK_OP_CLOSURE, reg_temp, (duk_regconst_t) fnum); declvar_flags = DUK_PROPDESC_FLAG_WRITABLE | DUK_PROPDESC_FLAG_ENUMERABLE | DUK_BC_DECLVAR_FLAG_FUNC_DECL; if (configurable_bindings) { declvar_flags |= DUK_PROPDESC_FLAG_CONFIGURABLE; } duk__emit_a_b_c(comp_ctx, DUK_OP_DECLVAR | DUK__EMIT_FLAG_NO_SHUFFLE_A | DUK__EMIT_FLAG_BC_REGCONST, (duk_regconst_t) declvar_flags /*flags*/, rc_name /*name*/, reg_temp /*value*/); DUK__SETTEMP(comp_ctx, reg_temp); /* forget temp */ } DUK_DDD(DUK_DDDPRINT("function declaration to varmap: %!T -> %!T", (duk_tval *) duk_get_tval(thr, -2), (duk_tval *) duk_get_tval(thr, -1))); #if defined(DUK_USE_FASTINT) DUK_ASSERT(DUK_TVAL_IS_NULL(duk_get_tval(thr, -1)) || DUK_TVAL_IS_FASTINT(duk_get_tval(thr, -1))); #endif duk_put_prop(thr, comp_ctx->curr_func.varmap_idx); /* [ ... name reg/null ] -> [ ... ] */ } /* * 'arguments' binding is special; if a shadowing argument or * function declaration exists, an arguments object will * definitely not be needed, regardless of whether the identifier * 'arguments' is referenced inside the function body. */ if (duk_has_prop_stridx(thr, comp_ctx->curr_func.varmap_idx, DUK_STRIDX_LC_ARGUMENTS)) { DUK_DDD(DUK_DDDPRINT("'arguments' is shadowed by argument or function declaration " "-> arguments object creation can be skipped")); comp_ctx->curr_func.is_arguments_shadowed = 1; } /* * Variable declarations. * * Unlike function declarations, variable declaration values don't get * assigned on entry. If a binding of the same name already exists, just * ignore it silently. */ for (i = 0; i < num_decls; i += 2) { duk_int_t decl_type; duk_get_prop_index(thr, comp_ctx->curr_func.decls_idx, i + 1); /* decl type */ decl_type = duk_to_int(thr, -1); decl_type = decl_type & 0xff; duk_pop(thr); if (decl_type != DUK_DECL_TYPE_VAR) { continue; } duk_get_prop_index(thr, comp_ctx->curr_func.decls_idx, i); /* decl name */ if (duk_has_prop(thr, comp_ctx->curr_func.varmap_idx)) { /* shadowed, ignore */ } else { duk_get_prop_index(thr, comp_ctx->curr_func.decls_idx, i); /* decl name */ h_name = duk_known_hstring(thr, -1); if (h_name == DUK_HTHREAD_STRING_LC_ARGUMENTS(thr) && !comp_ctx->curr_func.is_arguments_shadowed) { /* E5 Section steps 7-8 */ DUK_DDD(DUK_DDDPRINT("'arguments' not shadowed by a function declaration, " "but appears as a variable declaration -> treat as " "a no-op for variable declaration purposes")); duk_pop(thr); continue; } /* XXX: spilling */ if (comp_ctx->curr_func.is_function) { duk_regconst_t reg_bind = DUK__ALLOCTEMP(comp_ctx); /* no need to init reg, it will be undefined on entry */ duk_push_int(thr, (duk_int_t) reg_bind); } else { duk_dup_top(thr); rc_name = duk__getconst(comp_ctx); duk_push_null(thr); declvar_flags = DUK_PROPDESC_FLAG_WRITABLE | DUK_PROPDESC_FLAG_ENUMERABLE; if (configurable_bindings) { declvar_flags |= DUK_PROPDESC_FLAG_CONFIGURABLE; } duk__emit_a_b_c(comp_ctx, DUK_OP_DECLVAR | DUK__EMIT_FLAG_NO_SHUFFLE_A | DUK__EMIT_FLAG_BC_REGCONST, (duk_regconst_t) declvar_flags /*flags*/, rc_name /*name*/, 0 /*value*/); } duk_put_prop(thr, comp_ctx->curr_func.varmap_idx); /* [ ... name reg/null ] -> [ ... ] */ } } /* * Wrap up */ DUK_DDD(DUK_DDDPRINT("varmap: %!T, is_arguments_shadowed=%ld", (duk_tval *) duk_get_tval(thr, comp_ctx->curr_func.varmap_idx), (long) comp_ctx->curr_func.is_arguments_shadowed)); DUK_ASSERT_TOP(thr, entry_top); return; error_outofregs: DUK_ERROR_RANGE(thr, DUK_STR_REG_LIMIT); DUK_WO_NORETURN(return;); error_argname: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_ARG_NAME); DUK_WO_NORETURN(return;); } /* * Parse a function-body-like expression (FunctionBody or Program * in E5 grammar) using a two-pass parse. The productions appear * in the following contexts: * * - function expression * - function statement * - function declaration * - getter in object literal * - setter in object literal * - global code * - eval code * - Function constructor body * * This function only parses the statement list of the body; the argument * list and possible function name must be initialized by the caller. * For instance, for Function constructor, the argument names are originally * on the value stack. The parsing of statements ends either at an EOF or * a closing brace; this is controlled by an input flag. * * Note that there are many differences affecting parsing and even code * generation: * * - Global and eval code have an implicit return value generated * by the last statement; function code does not * * - Global code, eval code, and Function constructor body end in * an EOF, other bodies in a closing brace ('}') * * Upon entry, 'curr_tok' is ignored and the function will pull in the * first token on its own. Upon exit, 'curr_tok' is the terminating * token (EOF or closing brace). */ DUK_LOCAL void duk__parse_func_body(duk_compiler_ctx *comp_ctx, duk_bool_t expect_eof, duk_bool_t implicit_return_value, duk_bool_t regexp_after, duk_small_int_t expect_token) { duk_compiler_func *func; duk_hthread *thr; duk_regconst_t reg_stmt_value = -1; duk_lexer_point lex_pt; duk_regconst_t temp_first; duk_small_int_t compile_round = 1; DUK_ASSERT(comp_ctx != NULL); thr = comp_ctx->thr; DUK_ASSERT(thr != NULL); func = &comp_ctx->curr_func; DUK_ASSERT(func != NULL); DUK__RECURSION_INCREASE(comp_ctx, thr); duk_require_stack(thr, DUK__FUNCTION_BODY_REQUIRE_SLOTS); /* * Store lexer position for a later rewind */ DUK_LEXER_GETPOINT(&comp_ctx->lex, &lex_pt); /* * Program code (global and eval code) has an implicit return value * from the last statement value (e.g. eval("1; 2+3;") returns 3). * This is not the case with functions. If implicit statement return * value is requested, all statements are coerced to a register * allocated here, and used in the implicit return statement below. */ /* XXX: this is pointless here because pass 1 is throw-away */ if (implicit_return_value) { reg_stmt_value = DUK__ALLOCTEMP(comp_ctx); /* If an implicit return value is needed by caller, it must be * initialized to 'undefined' because we don't know whether any * non-empty (where "empty" is a continuation type, and different * from an empty statement) statements will be executed. * * However, since 1st pass is a throwaway one, no need to emit * it here. */ #if 0 duk__emit_bc(comp_ctx, DUK_OP_LDUNDEF, 0); #endif } /* * First pass. * * Gather variable/function declarations needed for second pass. * Code generated is dummy and discarded. */ func->in_directive_prologue = 1; func->in_scanning = 1; func->may_direct_eval = 0; func->id_access_arguments = 0; func->id_access_slow = 0; func->id_access_slow_own = 0; func->reg_stmt_value = reg_stmt_value; #if defined(DUK_USE_DEBUGGER_SUPPORT) func->min_line = DUK_INT_MAX; func->max_line = 0; #endif /* duk__parse_stmts() expects curr_tok to be set; parse in "allow * regexp literal" mode with current strictness. */ if (expect_token >= 0) { /* Eating a left curly; regexp mode is allowed by left curly * based on duk__token_lbp[] automatically. */ DUK_ASSERT(expect_token == DUK_TOK_LCURLY); duk__update_lineinfo_currtoken(comp_ctx); duk__advance_expect(comp_ctx, expect_token); } else { /* Need to set curr_token.t because lexing regexp mode depends on current * token type. Zero value causes "allow regexp" mode. */ comp_ctx->curr_token.t = 0; duk__advance(comp_ctx); } DUK_DDD(DUK_DDDPRINT("begin 1st pass")); duk__parse_stmts(comp_ctx, 1, /* allow source elements */ expect_eof, /* expect EOF instead of } */ regexp_after); /* regexp after */ DUK_DDD(DUK_DDDPRINT("end 1st pass")); /* * Second (and possibly third) pass. * * Generate actual code. In most cases the need for shuffle * registers is detected during pass 1, but in some corner cases * we'll only detect it during pass 2 and a third pass is then * needed (see GH-115). */ for (;;) { duk_bool_t needs_shuffle_before = comp_ctx->curr_func.needs_shuffle; compile_round++; /* * Rewind lexer. * * duk__parse_stmts() expects curr_tok to be set; parse in "allow regexp * literal" mode with current strictness. * * curr_token line number info should be initialized for pass 2 before * generating prologue, to ensure prologue bytecode gets nice line numbers. */ DUK_DDD(DUK_DDDPRINT("rewind lexer")); DUK_LEXER_SETPOINT(&comp_ctx->lex, &lex_pt); comp_ctx->curr_token.t = 0; /* this is needed for regexp mode */ comp_ctx->curr_token.start_line = 0; /* needed for line number tracking (becomes prev_token.start_line) */ duk__advance(comp_ctx); /* * Reset function state and perform register allocation, which creates * 'varmap' for second pass. Function prologue for variable declarations, * binding value initializations etc is emitted as a by-product. * * Strict mode restrictions for duplicate and invalid argument * names are checked here now that we know whether the function * is actually strict. See: test-dev-strict-mode-boundary.js. * * Inner functions are compiled during pass 1 and are not reset. */ duk__reset_func_for_pass2(comp_ctx); func->in_directive_prologue = 1; func->in_scanning = 0; /* must be able to emit code, alloc consts, etc. */ duk__init_varmap_and_prologue_for_pass2(comp_ctx, (implicit_return_value ? ®_stmt_value : NULL)); func->reg_stmt_value = reg_stmt_value; temp_first = DUK__GETTEMP(comp_ctx); func->temp_first = temp_first; func->temp_next = temp_first; func->stmt_next = 0; func->label_next = 0; /* XXX: init or assert catch depth etc -- all values */ func->id_access_arguments = 0; func->id_access_slow = 0; func->id_access_slow_own = 0; /* * Check function name validity now that we know strictness. * This only applies to function declarations and expressions, * not setter/getter name. * * See: test-dev-strict-mode-boundary.js */ if (func->is_function && !func->is_setget && func->h_name != NULL) { if (func->is_strict) { if (duk__hstring_is_eval_or_arguments(comp_ctx, func->h_name)) { DUK_DDD(DUK_DDDPRINT("func name is 'eval' or 'arguments' in strict mode")); goto error_funcname; } if (DUK_HSTRING_HAS_STRICT_RESERVED_WORD(func->h_name)) { DUK_DDD(DUK_DDDPRINT("func name is a reserved word in strict mode")); goto error_funcname; } } else { if (DUK_HSTRING_HAS_RESERVED_WORD(func->h_name) && !DUK_HSTRING_HAS_STRICT_RESERVED_WORD(func->h_name)) { DUK_DDD(DUK_DDDPRINT("func name is a reserved word in non-strict mode")); goto error_funcname; } } } /* * Second pass parsing. */ if (implicit_return_value) { /* Default implicit return value. */ duk__emit_bc(comp_ctx, DUK_OP_LDUNDEF, 0); } DUK_DDD(DUK_DDDPRINT("begin 2nd pass")); duk__parse_stmts(comp_ctx, 1, /* allow source elements */ expect_eof, /* expect EOF instead of } */ regexp_after); /* regexp after */ DUK_DDD(DUK_DDDPRINT("end 2nd pass")); duk__update_lineinfo_currtoken(comp_ctx); if (needs_shuffle_before == comp_ctx->curr_func.needs_shuffle) { /* Shuffle decision not changed. */ break; } if (compile_round >= 3) { /* Should never happen but avoid infinite loop just in case. */ DUK_D(DUK_DPRINT("more than 3 compile passes needed, should never happen")); DUK_ERROR_INTERNAL(thr); DUK_WO_NORETURN(return;); } DUK_D(DUK_DPRINT("need additional round to compile function, round now %d", (int) compile_round)); } /* * Emit a final RETURN. * * It would be nice to avoid emitting an unnecessary "return" opcode * if the current PC is not reachable. However, this cannot be reliably * detected; even if the previous instruction is an unconditional jump, * there may be a previous jump which jumps to current PC (which is the * case for iteration and conditional statements, for instance). */ /* XXX: request a "last statement is terminal" from duk__parse_stmt() and duk__parse_stmts(); * we could avoid the last RETURN if we could ensure there is no way to get here * (directly or via a jump) */ DUK_ASSERT(comp_ctx->curr_func.catch_depth == 0); if (reg_stmt_value >= 0) { DUK_ASSERT(DUK__ISREG(reg_stmt_value)); duk__emit_bc(comp_ctx, DUK_OP_RETREG, reg_stmt_value /*reg*/); } else { duk__emit_op_only(comp_ctx, DUK_OP_RETUNDEF); } /* * Peephole optimize JUMP chains. */ duk__peephole_optimize_bytecode(comp_ctx); /* * comp_ctx->curr_func is now ready to be converted into an actual * function template. */ DUK__RECURSION_DECREASE(comp_ctx, thr); return; error_funcname: DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_FUNC_NAME); DUK_WO_NORETURN(return;); } /* * Parse a function-like expression: * * - function expression * - function declaration * - function statement (non-standard) * - setter/getter * * Adds the function to comp_ctx->curr_func function table and returns the * function number. * * On entry, curr_token points to: * * - the token after 'function' for function expression/declaration/statement * - the token after 'set' or 'get' for setter/getter */ /* Parse formals. */ DUK_LOCAL void duk__parse_func_formals(duk_compiler_ctx *comp_ctx) { duk_hthread *thr = comp_ctx->thr; duk_bool_t first = 1; duk_uarridx_t n; for (;;) { if (comp_ctx->curr_token.t == DUK_TOK_RPAREN) { break; } if (first) { /* no comma */ first = 0; } else { duk__advance_expect(comp_ctx, DUK_TOK_COMMA); } /* Note: when parsing a formal list in non-strict context, e.g. * "implements" is parsed as an identifier. When the function is * later detected to be strict, the argument list must be rechecked * against a larger set of reserved words (that of strict mode). * This is handled by duk__parse_func_body(). Here we recognize * whatever tokens are considered reserved in current strictness * (which is not always enough). */ if (comp_ctx->curr_token.t != DUK_TOK_IDENTIFIER) { DUK_ERROR_SYNTAX(thr, DUK_STR_EXPECTED_IDENTIFIER); DUK_WO_NORETURN(return;); } DUK_ASSERT(comp_ctx->curr_token.t == DUK_TOK_IDENTIFIER); DUK_ASSERT(comp_ctx->curr_token.str1 != NULL); DUK_DDD(DUK_DDDPRINT("formal argument: %!O", (duk_heaphdr *) comp_ctx->curr_token.str1)); /* XXX: append primitive */ duk_push_hstring(thr, comp_ctx->curr_token.str1); n = (duk_uarridx_t) duk_get_length(thr, comp_ctx->curr_func.argnames_idx); duk_put_prop_index(thr, comp_ctx->curr_func.argnames_idx, n); duk__advance(comp_ctx); /* eat identifier */ } } /* Parse a function-like expression, assuming that 'comp_ctx->curr_func' is * correctly set up. Assumes that curr_token is just after 'function' (or * 'set'/'get' etc). */ DUK_LOCAL void duk__parse_func_like_raw(duk_compiler_ctx *comp_ctx, duk_small_uint_t flags) { duk_hthread *thr = comp_ctx->thr; duk_token *tok; duk_bool_t no_advance; DUK_ASSERT(comp_ctx->curr_func.num_formals == 0); DUK_ASSERT(comp_ctx->curr_func.is_function == 1); DUK_ASSERT(comp_ctx->curr_func.is_eval == 0); DUK_ASSERT(comp_ctx->curr_func.is_global == 0); DUK_ASSERT(comp_ctx->curr_func.is_setget == ((flags & DUK__FUNC_FLAG_GETSET) != 0)); duk__update_lineinfo_currtoken(comp_ctx); /* * Function name (if any) * * We don't check for prohibited names here, because we don't * yet know whether the function will be strict. Function body * parsing handles this retroactively. * * For function expressions and declarations function name must * be an Identifer (excludes reserved words). For setter/getter * it is a PropertyName which allows reserved words and also * strings and numbers (e.g. "{ get 1() { ... } }"). * * Function parsing may start either from prev_token or curr_token * (object literal method definition uses prev_token for example). * This is dealt with for the initial token. */ no_advance = (flags & DUK__FUNC_FLAG_USE_PREVTOKEN); if (no_advance) { tok = &comp_ctx->prev_token; } else { tok = &comp_ctx->curr_token; } if (flags & DUK__FUNC_FLAG_GETSET) { /* PropertyName -> IdentifierName | StringLiteral | NumericLiteral */ if (tok->t_nores == DUK_TOK_IDENTIFIER || tok->t == DUK_TOK_STRING) { duk_push_hstring(thr, tok->str1); /* keep in valstack */ } else if (tok->t == DUK_TOK_NUMBER) { duk_push_number(thr, tok->num); duk_to_string(thr, -1); } else { DUK_ERROR_SYNTAX(thr, DUK_STR_INVALID_GETSET_NAME); DUK_WO_NORETURN(return;); } comp_ctx->curr_func.h_name = duk_known_hstring(thr, -1); /* borrowed reference */ } else { /* Function name is an Identifier (not IdentifierName), but we get * the raw name (not recognizing keywords) here and perform the name * checks only after pass 1. */ if (tok->t_nores == DUK_TOK_IDENTIFIER) { duk_push_hstring(thr, tok->str1); /* keep in valstack */ comp_ctx->curr_func.h_name = duk_known_hstring(thr, -1); /* borrowed reference */ } else { /* valstack will be unbalanced, which is OK */ DUK_ASSERT((flags & DUK__FUNC_FLAG_GETSET) == 0); DUK_ASSERT(comp_ctx->curr_func.h_name == NULL); no_advance = 1; if (flags & DUK__FUNC_FLAG_DECL) { DUK_ERROR_SYNTAX(thr, DUK_STR_FUNC_NAME_REQUIRED); DUK_WO_NORETURN(return;); } } } DUK_DD(DUK_DDPRINT("function name: %!O", (duk_heaphdr *) comp_ctx->curr_func.h_name)); if (!no_advance) { duk__advance(comp_ctx); } /* * Formal argument list * * We don't check for prohibited names or for duplicate argument * names here, becase we don't yet know whether the function will * be strict. Function body parsing handles this retroactively. */ duk__advance_expect(comp_ctx, DUK_TOK_LPAREN); duk__parse_func_formals(comp_ctx); DUK_ASSERT(comp_ctx->curr_token.t == DUK_TOK_RPAREN); duk__advance(comp_ctx); /* * Parse function body */ duk__parse_func_body(comp_ctx, 0, /* expect_eof */ 0, /* implicit_return_value */ flags & DUK__FUNC_FLAG_DECL, /* regexp_after */ DUK_TOK_LCURLY); /* expect_token */ /* * Convert duk_compiler_func to a function template and add it * to the parent function table. */ duk__convert_to_func_template(comp_ctx); /* -> [ ... func ] */ } /* Parse an inner function, adding the function template to the current function's * function table. Return a function number to be used by the outer function. * * Avoiding O(depth^2) inner function parsing is handled here. On the first pass, * compile and register the function normally into the 'funcs' array, also recording * a lexer point (offset/line) to the closing brace of the function. On the second * pass, skip the function and return the same 'fnum' as on the first pass by using * a running counter. * * An unfortunate side effect of this is that when parsing the inner function, almost * nothing is known of the outer function, i.e. the inner function's scope. We don't * need that information at the moment, but it would allow some optimizations if it * were used. */ DUK_LOCAL duk_int_t duk__parse_func_like_fnum(duk_compiler_ctx *comp_ctx, duk_small_uint_t flags) { duk_hthread *thr = comp_ctx->thr; duk_compiler_func old_func; duk_idx_t entry_top; duk_int_t fnum; /* * On second pass, skip the function. */ if (!comp_ctx->curr_func.in_scanning) { duk_lexer_point lex_pt; fnum = comp_ctx->curr_func.fnum_next++; duk_get_prop_index(thr, comp_ctx->curr_func.funcs_idx, (duk_uarridx_t) (fnum * 3 + 1)); lex_pt.offset = (duk_size_t) duk_to_uint(thr, -1); duk_pop(thr); duk_get_prop_index(thr, comp_ctx->curr_func.funcs_idx, (duk_uarridx_t) (fnum * 3 + 2)); lex_pt.line = duk_to_int(thr, -1); duk_pop(thr); DUK_DDD(DUK_DDDPRINT("second pass of an inner func, skip the function, reparse closing brace; lex offset=%ld, line=%ld", (long) lex_pt.offset, (long) lex_pt.line)); DUK_LEXER_SETPOINT(&comp_ctx->lex, &lex_pt); comp_ctx->curr_token.t = 0; /* this is needed for regexp mode */ comp_ctx->curr_token.start_line = 0; /* needed for line number tracking (becomes prev_token.start_line) */ duk__advance(comp_ctx); /* RegExp is not allowed after a function expression, e.g. in * (function () {} / 123). A RegExp *is* allowed after a * function declaration! */ if (flags & DUK__FUNC_FLAG_DECL) { comp_ctx->curr_func.allow_regexp_in_adv = 1; } duk__advance_expect(comp_ctx, DUK_TOK_RCURLY); return fnum; } /* * On first pass, perform actual parsing. Remember valstack top on entry * to restore it later, and switch to using a new function in comp_ctx. */ entry_top = duk_get_top(thr); DUK_DDD(DUK_DDDPRINT("before func: entry_top=%ld, curr_tok.start_offset=%ld", (long) entry_top, (long) comp_ctx->curr_token.start_offset)); duk_memcpy(&old_func, &comp_ctx->curr_func, sizeof(duk_compiler_func)); duk_memzero(&comp_ctx->curr_func, sizeof(duk_compiler_func)); duk__init_func_valstack_slots(comp_ctx); DUK_ASSERT(comp_ctx->curr_func.num_formals == 0); /* inherit initial strictness from parent */ comp_ctx->curr_func.is_strict = old_func.is_strict; /* XXX: It might be better to just store the flags into the curr_func * struct and use them as is without this flag interpretation step * here. */ DUK_ASSERT(comp_ctx->curr_func.is_notail == 0); comp_ctx->curr_func.is_function = 1; DUK_ASSERT(comp_ctx->curr_func.is_eval == 0); DUK_ASSERT(comp_ctx->curr_func.is_global == 0); comp_ctx->curr_func.is_setget = ((flags & DUK__FUNC_FLAG_GETSET) != 0); comp_ctx->curr_func.is_namebinding = !(flags & (DUK__FUNC_FLAG_GETSET | DUK__FUNC_FLAG_METDEF | DUK__FUNC_FLAG_DECL)); /* no name binding for: declarations, objlit getset, objlit method def */ comp_ctx->curr_func.is_constructable = !(flags & (DUK__FUNC_FLAG_GETSET | DUK__FUNC_FLAG_METDEF)); /* not constructable: objlit getset, objlit method def */ /* * Parse inner function */ duk__parse_func_like_raw(comp_ctx, flags); /* pushes function template */ /* prev_token.start_offset points to the closing brace here; when skipping * we're going to reparse the closing brace to ensure semicolon insertion * etc work as expected. */ DUK_DDD(DUK_DDDPRINT("after func: prev_tok.start_offset=%ld, curr_tok.start_offset=%ld", (long) comp_ctx->prev_token.start_offset, (long) comp_ctx->curr_token.start_offset)); DUK_ASSERT(comp_ctx->lex.input[comp_ctx->prev_token.start_offset] == (duk_uint8_t) DUK_ASC_RCURLY); /* XXX: append primitive */ DUK_ASSERT(duk_get_length(thr, old_func.funcs_idx) == (duk_size_t) (old_func.fnum_next * 3)); fnum = old_func.fnum_next++; if (fnum > DUK__MAX_FUNCS) { DUK_ERROR_RANGE(comp_ctx->thr, DUK_STR_FUNC_LIMIT); DUK_WO_NORETURN(return 0;); } /* array writes autoincrement length */ (void) duk_put_prop_index(thr, old_func.funcs_idx, (duk_uarridx_t) (fnum * 3)); duk_push_size_t(thr, comp_ctx->prev_token.start_offset); (void) duk_put_prop_index(thr, old_func.funcs_idx, (duk_uarridx_t) (fnum * 3 + 1)); duk_push_int(thr, comp_ctx->prev_token.start_line); (void) duk_put_prop_index(thr, old_func.funcs_idx, (duk_uarridx_t) (fnum * 3 + 2)); /* * Cleanup: restore original function, restore valstack state. * * Function declaration handling needs the function name to be pushed * on the value stack. */ if (flags & DUK__FUNC_FLAG_PUSHNAME_PASS1) { DUK_ASSERT(comp_ctx->curr_func.h_name != NULL); duk_push_hstring(thr, comp_ctx->curr_func.h_name); duk_replace(thr, entry_top); duk_set_top(thr, entry_top + 1); } else { duk_set_top(thr, entry_top); } duk_memcpy((void *) &comp_ctx->curr_func, (void *) &old_func, sizeof(duk_compiler_func)); return fnum; } /* * Compile input string into an executable function template without * arguments. * * The string is parsed as the "Program" production of ECMAScript E5. * Compilation context can be either global code or eval code (see E5 * Sections 14 and 15.1.2.1). * * Input stack: [ ... filename ] * Output stack: [ ... func_template ] */ /* XXX: source code property */ DUK_LOCAL duk_ret_t duk__js_compile_raw(duk_hthread *thr, void *udata) { duk_hstring *h_filename; duk__compiler_stkstate *comp_stk; duk_compiler_ctx *comp_ctx; duk_lexer_point *lex_pt; duk_compiler_func *func; duk_idx_t entry_top; duk_bool_t is_strict; duk_bool_t is_eval; duk_bool_t is_funcexpr; duk_small_uint_t flags; DUK_ASSERT(thr != NULL); DUK_ASSERT(udata != NULL); /* * Arguments check */ entry_top = duk_get_top(thr); DUK_ASSERT(entry_top >= 1); comp_stk = (duk__compiler_stkstate *) udata; comp_ctx = &comp_stk->comp_ctx_alloc; lex_pt = &comp_stk->lex_pt_alloc; DUK_ASSERT(comp_ctx != NULL); DUK_ASSERT(lex_pt != NULL); flags = comp_stk->flags; is_eval = (flags & DUK_COMPILE_EVAL ? 1 : 0); is_strict = (flags & DUK_COMPILE_STRICT ? 1 : 0); is_funcexpr = (flags & DUK_COMPILE_FUNCEXPR ? 1 : 0); h_filename = duk_get_hstring(thr, -1); /* may be undefined */ /* * Init compiler and lexer contexts */ func = &comp_ctx->curr_func; #if defined(DUK_USE_EXPLICIT_NULL_INIT) comp_ctx->thr = NULL; comp_ctx->h_filename = NULL; comp_ctx->prev_token.str1 = NULL; comp_ctx->prev_token.str2 = NULL; comp_ctx->curr_token.str1 = NULL; comp_ctx->curr_token.str2 = NULL; #endif duk_require_stack(thr, DUK__COMPILE_ENTRY_SLOTS); duk_push_dynamic_buffer(thr, 0); /* entry_top + 0 */ duk_push_undefined(thr); /* entry_top + 1 */ duk_push_undefined(thr); /* entry_top + 2 */ duk_push_undefined(thr); /* entry_top + 3 */ duk_push_undefined(thr); /* entry_top + 4 */ comp_ctx->thr = thr; comp_ctx->h_filename = h_filename; comp_ctx->tok11_idx = entry_top + 1; comp_ctx->tok12_idx = entry_top + 2; comp_ctx->tok21_idx = entry_top + 3; comp_ctx->tok22_idx = entry_top + 4; comp_ctx->recursion_limit = DUK_USE_COMPILER_RECLIMIT; /* comp_ctx->lex has been pre-initialized by caller: it has been * zeroed and input/input_length has been set. */ comp_ctx->lex.thr = thr; /* comp_ctx->lex.input and comp_ctx->lex.input_length filled by caller */ comp_ctx->lex.slot1_idx = comp_ctx->tok11_idx; comp_ctx->lex.slot2_idx = comp_ctx->tok12_idx; comp_ctx->lex.buf_idx = entry_top + 0; comp_ctx->lex.buf = (duk_hbuffer_dynamic *) duk_known_hbuffer(thr, entry_top + 0); DUK_ASSERT(DUK_HBUFFER_HAS_DYNAMIC(comp_ctx->lex.buf) && !DUK_HBUFFER_HAS_EXTERNAL(comp_ctx->lex.buf)); comp_ctx->lex.token_limit = DUK_COMPILER_TOKEN_LIMIT; lex_pt->offset = 0; lex_pt->line = 1; DUK_LEXER_SETPOINT(&comp_ctx->lex, lex_pt); /* fills window */ comp_ctx->curr_token.start_line = 0; /* needed for line number tracking (becomes prev_token.start_line) */ /* * Initialize function state for a zero-argument function */ duk__init_func_valstack_slots(comp_ctx); DUK_ASSERT(func->num_formals == 0); if (is_funcexpr) { /* Name will be filled from function expression, not by caller. * This case is used by Function constructor and duk_compile() * API with the DUK_COMPILE_FUNCTION option. */ DUK_ASSERT(func->h_name == NULL); } else { duk_push_hstring_stridx(thr, (is_eval ? DUK_STRIDX_EVAL : DUK_STRIDX_GLOBAL)); func->h_name = duk_get_hstring(thr, -1); } /* * Parse a function body or a function-like expression, depending * on flags. */ DUK_ASSERT(func->is_setget == 0); func->is_strict = (duk_uint8_t) is_strict; DUK_ASSERT(func->is_notail == 0); if (is_funcexpr) { func->is_function = 1; DUK_ASSERT(func->is_eval == 0); DUK_ASSERT(func->is_global == 0); func->is_namebinding = 1; func->is_constructable = 1; duk__advance(comp_ctx); /* init 'curr_token' */ duk__advance_expect(comp_ctx, DUK_TOK_FUNCTION); (void) duk__parse_func_like_raw(comp_ctx, 0 /*flags*/); } else { DUK_ASSERT(func->is_function == 0); DUK_ASSERT(is_eval == 0 || is_eval == 1); func->is_eval = (duk_uint8_t) is_eval; func->is_global = (duk_uint8_t) !is_eval; DUK_ASSERT(func->is_namebinding == 0); DUK_ASSERT(func->is_constructable == 0); duk__parse_func_body(comp_ctx, 1, /* expect_eof */ 1, /* implicit_return_value */ 1, /* regexp_after (does not matter) */ -1); /* expect_token */ } /* * Convert duk_compiler_func to a function template */ duk__convert_to_func_template(comp_ctx); /* * Wrapping duk_safe_call() will mangle the stack, just return stack top */ /* [ ... filename (temps) func ] */ return 1; } DUK_INTERNAL void duk_js_compile(duk_hthread *thr, const duk_uint8_t *src_buffer, duk_size_t src_length, duk_small_uint_t flags) { duk__compiler_stkstate comp_stk; duk_compiler_ctx *prev_ctx; duk_ret_t safe_rc; DUK_ASSERT(thr != NULL); DUK_ASSERT(src_buffer != NULL); /* preinitialize lexer state partially */ duk_memzero(&comp_stk, sizeof(comp_stk)); comp_stk.flags = flags; DUK_LEXER_INITCTX(&comp_stk.comp_ctx_alloc.lex); comp_stk.comp_ctx_alloc.lex.input = src_buffer; comp_stk.comp_ctx_alloc.lex.input_length = src_length; comp_stk.comp_ctx_alloc.lex.flags = flags; /* Forward flags directly for now. */ /* [ ... filename ] */ prev_ctx = thr->compile_ctx; thr->compile_ctx = &comp_stk.comp_ctx_alloc; /* for duk_error_augment.c */ safe_rc = duk_safe_call(thr, duk__js_compile_raw, (void *) &comp_stk /*udata*/, 1 /*nargs*/, 1 /*nrets*/); thr->compile_ctx = prev_ctx; /* must restore reliably before returning */ if (safe_rc != DUK_EXEC_SUCCESS) { DUK_D(DUK_DPRINT("compilation failed: %!T", duk_get_tval(thr, -1))); (void) duk_throw(thr); DUK_WO_NORETURN(return;); } /* [ ... template ] */ }