1 /* 2 * Ecmascript compiler. 3 */ 4 5 #ifndef DUK_JS_COMPILER_H_INCLUDED 6 #define DUK_JS_COMPILER_H_INCLUDED 7 8 /* ecmascript compiler limits */ 9 #define DUK_COMPILER_TOKEN_LIMIT 100000000L /* 1e8: protects against deeply nested inner functions */ 10 11 /* maximum loopcount for peephole optimization */ 12 #define DUK_COMPILER_PEEPHOLE_MAXITER 3 13 14 /* maximum bytecode length in instructions */ 15 #define DUK_COMPILER_MAX_BYTECODE_LENGTH (256L * 1024L * 1024L) /* 1 GB */ 16 17 /* 18 * Compiler intermediate values 19 * 20 * Intermediate values describe either plain values (e.g. strings or 21 * numbers) or binary operations which have not yet been coerced into 22 * either a left-hand-side or right-hand-side role (e.g. object property). 23 */ 24 25 #define DUK_IVAL_NONE 0 /* no value */ 26 #define DUK_IVAL_PLAIN 1 /* register, constant, or value */ 27 #define DUK_IVAL_ARITH 2 /* binary arithmetic; DUK_OP_ADD, DUK_OP_EQ, other binary ops */ 28 #define DUK_IVAL_ARITH_EXTRAOP 3 /* binary arithmetic using extraops; DUK_EXTRAOP_INSTOF etc */ 29 #define DUK_IVAL_PROP 4 /* property access */ 30 #define DUK_IVAL_VAR 5 /* variable access */ 31 32 #define DUK_ISPEC_NONE 0 /* no value */ 33 #define DUK_ISPEC_VALUE 1 /* value resides in 'valstack_idx' */ 34 #define DUK_ISPEC_REGCONST 2 /* value resides in a register or constant */ 35 36 /* bit mask which indicates that a regconst is a constant instead of a register */ 37 #define DUK_JS_CONST_MARKER 0x80000000UL 38 39 /* type to represent a reg/const reference during compilation */ 40 typedef duk_uint32_t duk_regconst_t; 41 42 /* type to represent a straight register reference, with <0 indicating none */ 43 typedef duk_int32_t duk_reg_t; 44 45 typedef struct { 46 duk_small_uint_t t; /* DUK_ISPEC_XXX */ 47 duk_regconst_t regconst; 48 duk_idx_t valstack_idx; /* always set; points to a reserved valstack slot */ 49 } duk_ispec; 50 51 typedef struct { 52 /* 53 * PLAIN: x1 54 * ARITH: x1 <op> x2 55 * PROP: x1.x2 56 * VAR: x1 (name) 57 */ 58 59 /* XXX: can be optimized for smaller footprint esp. on 32-bit environments */ 60 duk_small_uint_t t; /* DUK_IVAL_XXX */ 61 duk_small_uint_t op; /* bytecode opcode (or extraop) for binary ops */ 62 duk_ispec x1; 63 duk_ispec x2; 64 } duk_ivalue; 65 66 /* 67 * Bytecode instruction representation during compilation 68 * 69 * Contains the actual instruction and (optionally) debug info. 70 */ 71 72 struct duk_compiler_instr { 73 duk_instr_t ins; 74 #if defined(DUK_USE_PC2LINE) 75 duk_uint32_t line; 76 #endif 77 }; 78 79 /* 80 * Compiler state 81 */ 82 83 #define DUK_LABEL_FLAG_ALLOW_BREAK (1 << 0) 84 #define DUK_LABEL_FLAG_ALLOW_CONTINUE (1 << 1) 85 86 #define DUK_DECL_TYPE_VAR 0 87 #define DUK_DECL_TYPE_FUNC 1 88 89 /* XXX: optimize to 16 bytes */ 90 typedef struct { 91 duk_small_uint_t flags; 92 duk_int_t label_id; /* numeric label_id (-1 reserved as marker) */ 93 duk_hstring *h_label; /* borrowed label name */ 94 duk_int_t catch_depth; /* catch depth at point of definition */ 95 duk_int_t pc_label; /* pc of label statement: 96 * pc+1: break jump site 97 * pc+2: continue jump site 98 */ 99 100 /* Fast jumps (which avoid longjmp) jump directly to the jump sites 101 * which are always known even while the iteration/switch statement 102 * is still being parsed. A final peephole pass "straightens out" 103 * the jumps. 104 */ 105 } duk_labelinfo; 106 107 /* Compiling state of one function, eventually converted to duk_hcompiledfunction */ 108 struct duk_compiler_func { 109 /* These pointers are at the start of the struct so that they pack 110 * nicely. Mixing pointers and integer values is bad on some 111 * platforms (e.g. if int is 32 bits and pointers are 64 bits). 112 */ 113 114 duk_bufwriter_ctx bw_code; /* bufwriter for code */ 115 116 duk_hstring *h_name; /* function name (borrowed reference), ends up in _name */ 117 /* h_code: held in bw_code */ 118 duk_hobject *h_consts; /* array */ 119 duk_hobject *h_funcs; /* array of function templates: [func1, offset1, line1, func2, offset2, line2] 120 * offset/line points to closing brace to allow skipping on pass 2 121 */ 122 duk_hobject *h_decls; /* array of declarations: [ name1, val1, name2, val2, ... ] 123 * valN = (typeN) | (fnum << 8), where fnum is inner func number (0 for vars) 124 * record function and variable declarations in pass 1 125 */ 126 duk_hobject *h_labelnames; /* array of active label names */ 127 duk_hbuffer_dynamic *h_labelinfos; /* C array of duk_labelinfo */ 128 duk_hobject *h_argnames; /* array of formal argument names (-> _Formals) */ 129 duk_hobject *h_varmap; /* variable map for pass 2 (identifier -> register number or null (unmapped)) */ 130 131 /* value stack indices for tracking objects */ 132 /* code_idx: not needed */ 133 duk_idx_t consts_idx; 134 duk_idx_t funcs_idx; 135 duk_idx_t decls_idx; 136 duk_idx_t labelnames_idx; 137 duk_idx_t labelinfos_idx; 138 duk_idx_t argnames_idx; 139 duk_idx_t varmap_idx; 140 141 /* temp reg handling */ 142 duk_reg_t temp_first; /* first register that is a temporary (below: variables) */ 143 duk_reg_t temp_next; /* next temporary register to allocate */ 144 duk_reg_t temp_max; /* highest value of temp_reg (temp_max - 1 is highest used reg) */ 145 146 /* shuffle registers if large number of regs/consts */ 147 duk_reg_t shuffle1; 148 duk_reg_t shuffle2; 149 duk_reg_t shuffle3; 150 151 /* stats for current expression being parsed */ 152 duk_int_t nud_count; 153 duk_int_t led_count; 154 duk_int_t paren_level; /* parenthesis count, 0 = top level */ 155 duk_bool_t expr_lhs; /* expression is left-hand-side compatible */ 156 duk_bool_t allow_in; /* current paren level allows 'in' token */ 157 158 /* misc */ 159 duk_int_t stmt_next; /* statement id allocation (running counter) */ 160 duk_int_t label_next; /* label id allocation (running counter) */ 161 duk_int_t catch_depth; /* catch stack depth */ 162 duk_int_t with_depth; /* with stack depth (affects identifier lookups) */ 163 duk_int_t fnum_next; /* inner function numbering */ 164 duk_int_t num_formals; /* number of formal arguments */ 165 duk_reg_t reg_stmt_value; /* register for writing value of 'non-empty' statements (global or eval code), -1 is marker */ 166 #if defined(DUK_USE_DEBUGGER_SUPPORT) 167 duk_int_t min_line; /* XXX: typing (duk_hcompiledfunction has duk_uint32_t) */ 168 duk_int_t max_line; 169 #endif 170 171 /* status booleans */ 172 duk_bool_t is_function; /* is an actual function (not global/eval code) */ 173 duk_bool_t is_eval; /* is eval code */ 174 duk_bool_t is_global; /* is global code */ 175 duk_bool_t is_setget; /* is a setter/getter */ 176 duk_bool_t is_decl; /* is a function declaration (as opposed to function expression) */ 177 duk_bool_t is_strict; /* function is strict */ 178 duk_bool_t is_notail; /* function must not be tail called */ 179 duk_bool_t in_directive_prologue; /* parsing in "directive prologue", recognize directives */ 180 duk_bool_t in_scanning; /* parsing in "scanning" phase (first pass) */ 181 duk_bool_t may_direct_eval; /* function may call direct eval */ 182 duk_bool_t id_access_arguments; /* function refers to 'arguments' identifier */ 183 duk_bool_t id_access_slow; /* function makes one or more slow path accesses */ 184 duk_bool_t is_arguments_shadowed; /* argument/function declaration shadows 'arguments' */ 185 duk_bool_t needs_shuffle; /* function needs shuffle registers */ 186 duk_bool_t reject_regexp_in_adv; /* reject RegExp literal on next advance() call; needed for handling IdentifierName productions */ 187 }; 188 189 struct duk_compiler_ctx { 190 duk_hthread *thr; 191 192 /* filename being compiled (ends up in functions' '_filename' property) */ 193 duk_hstring *h_filename; /* borrowed reference */ 194 195 /* lexing (tokenization) state (contains two valstack slot indices) */ 196 duk_lexer_ctx lex; 197 198 /* current and previous token for parsing */ 199 duk_token prev_token; 200 duk_token curr_token; 201 duk_idx_t tok11_idx; /* curr_token slot1 (matches 'lex' slot1_idx) */ 202 duk_idx_t tok12_idx; /* curr_token slot2 (matches 'lex' slot2_idx) */ 203 duk_idx_t tok21_idx; /* prev_token slot1 */ 204 duk_idx_t tok22_idx; /* prev_token slot2 */ 205 206 /* recursion limit */ 207 duk_int_t recursion_depth; 208 duk_int_t recursion_limit; 209 210 /* code emission temporary */ 211 duk_int_t emit_jumpslot_pc; 212 213 /* current function being compiled (embedded instead of pointer for more compact access) */ 214 duk_compiler_func curr_func; 215 }; 216 217 /* 218 * Prototypes 219 */ 220 221 #define DUK_JS_COMPILE_FLAG_EVAL (1 << 0) /* source is eval code (not global) */ 222 #define DUK_JS_COMPILE_FLAG_STRICT (1 << 1) /* strict outer context */ 223 #define DUK_JS_COMPILE_FLAG_FUNCEXPR (1 << 2) /* source is a function expression (used for Function constructor) */ 224 225 DUK_INTERNAL_DECL void duk_js_compile(duk_hthread *thr, const duk_uint8_t *src_buffer, duk_size_t src_length, duk_small_uint_t flags); 226 227 #endif /* DUK_JS_COMPILER_H_INCLUDED */ 228