/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=8 sts=4 et sw=4 tw=99: * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef jsopcode_h #define jsopcode_h /* * JS bytecode definitions. */ #include #include "jsprvtd.h" #include "jspubtd.h" #include "jsutil.h" /* * JS operation bytecodes. */ typedef enum JSOp { #define OPDEF(op,val,name,token,length,nuses,ndefs,format) \ op = val, #include "jsopcode.tbl" #undef OPDEF JSOP_LIMIT, /* * These pseudo-ops help js_DecompileValueGenerator decompile JSOP_SETPROP, * JSOP_SETELEM, and comprehension-tails, respectively. They are never * stored in bytecode, so they don't preempt valid opcodes. */ JSOP_GETPROP2 = JSOP_LIMIT, JSOP_GETELEM2 = JSOP_LIMIT + 1, JSOP_FORLOCAL = JSOP_LIMIT + 2, JSOP_FAKE_LIMIT = JSOP_FORLOCAL } JSOp; /* * JS bytecode formats. */ #define JOF_BYTE 0 /* single bytecode, no immediates */ #define JOF_JUMP 1 /* signed 16-bit jump offset immediate */ #define JOF_ATOM 2 /* unsigned 16-bit constant index */ #define JOF_UINT16 3 /* unsigned 16-bit immediate operand */ #define JOF_TABLESWITCH 4 /* table switch */ /* 5 is unused */ #define JOF_QARG 6 /* quickened get/set function argument ops */ #define JOF_LOCAL 7 /* var or block-local variable */ #define JOF_DOUBLE 8 /* uint32_t index for double value */ #define JOF_UINT24 12 /* extended unsigned 24-bit literal (index) */ #define JOF_UINT8 13 /* uint8_t immediate, e.g. top 8 bits of 24-bit atom index */ #define JOF_INT32 14 /* int32_t immediate operand */ #define JOF_OBJECT 15 /* unsigned 16-bit object index */ #define JOF_SLOTOBJECT 16 /* uint16_t slot index + object index */ #define JOF_REGEXP 17 /* unsigned 32-bit regexp index */ #define JOF_INT8 18 /* int8_t immediate operand */ #define JOF_ATOMOBJECT 19 /* uint16_t constant index + object index */ #define JOF_UINT16PAIR 20 /* pair of uint16_t immediates */ #define JOF_SCOPECOORD 21 /* pair of uint16_t immediates followed by block index */ #define JOF_TYPEMASK 0x001f /* mask for above immediate types */ #define JOF_NAME (1U<<5) /* name operation */ #define JOF_PROP (2U<<5) /* obj.prop operation */ #define JOF_ELEM (3U<<5) /* obj[index] operation */ #define JOF_MODEMASK (7U<<5) /* mask for above addressing modes */ #define JOF_SET (1U<<8) /* set (i.e., assignment) operation */ /* (1U<<9) is unused*/ /* (1U<<10) is unused*/ /* (1U<<11) is unused*/ /* (1U<<12) is unused*/ /* (1U<<13) is unused*/ #define JOF_DETECTING (1U<<14) /* object detection for warning-quelling */ /* (1U<<15) is unused*/ #define JOF_LEFTASSOC (1U<<16) /* left-associative operator */ /* (1U<<17) is unused */ /* (1U<<18) is unused */ /* (1U<<19) is unused*/ /* (1U<<20) is unused*/ #define JOF_INVOKE (1U<<21) /* JSOP_CALL, JSOP_NEW, JSOP_EVAL */ #define JOF_TMPSLOT (1U<<22) /* interpreter uses extra temporary slot to root intermediate objects besides the slots opcode uses */ #define JOF_TMPSLOT2 (2U<<22) /* interpreter uses extra 2 temporary slot besides the slots opcode uses */ #define JOF_TMPSLOT3 (3U<<22) /* interpreter uses extra 3 temporary slot besides the slots opcode uses */ #define JOF_TMPSLOT_SHIFT 22 #define JOF_TMPSLOT_MASK (JS_BITMASK(2) << JOF_TMPSLOT_SHIFT) /* (1U<<24) is unused */ #define JOF_GNAME (1U<<25) /* predicted global name */ #define JOF_TYPESET (1U<<26) /* has an entry in a script's type sets */ #define JOF_ARITH (1U<<27) /* unary or binary arithmetic opcode */ /* Shorthands for type from format and type from opcode. */ #define JOF_TYPE(fmt) ((fmt) & JOF_TYPEMASK) #define JOF_OPTYPE(op) JOF_TYPE(js_CodeSpec[op].format) /* Shorthands for mode from format and mode from opcode. */ #define JOF_MODE(fmt) ((fmt) & JOF_MODEMASK) #define JOF_OPMODE(op) JOF_MODE(js_CodeSpec[op].format) /* * Immediate operand getters, setters, and bounds. */ static JS_ALWAYS_INLINE uint8_t GET_UINT8(jsbytecode *pc) { return (uint8_t) pc[1]; } static JS_ALWAYS_INLINE void SET_UINT8(jsbytecode *pc, uint8_t u) { pc[1] = (jsbytecode) u; } /* Common uint16_t immediate format helpers. */ #define UINT16_LEN 2 #define UINT16_HI(i) ((jsbytecode)((i) >> 8)) #define UINT16_LO(i) ((jsbytecode)(i)) #define GET_UINT16(pc) ((unsigned)(((pc)[1] << 8) | (pc)[2])) #define SET_UINT16(pc,i) ((pc)[1] = UINT16_HI(i), (pc)[2] = UINT16_LO(i)) #define UINT16_LIMIT ((unsigned)1 << 16) /* Helpers for accessing the offsets of jump opcodes. */ #define JUMP_OFFSET_LEN 4 #define JUMP_OFFSET_MIN INT32_MIN #define JUMP_OFFSET_MAX INT32_MAX static JS_ALWAYS_INLINE int32_t GET_JUMP_OFFSET(jsbytecode *pc) { return (pc[1] << 24) | (pc[2] << 16) | (pc[3] << 8) | pc[4]; } static JS_ALWAYS_INLINE void SET_JUMP_OFFSET(jsbytecode *pc, int32_t off) { pc[1] = (jsbytecode)(off >> 24); pc[2] = (jsbytecode)(off >> 16); pc[3] = (jsbytecode)(off >> 8); pc[4] = (jsbytecode)off; } #define UINT32_INDEX_LEN 4 static JS_ALWAYS_INLINE uint32_t GET_UINT32_INDEX(const jsbytecode *pc) { return (pc[1] << 24) | (pc[2] << 16) | (pc[3] << 8) | pc[4]; } static JS_ALWAYS_INLINE void SET_UINT32_INDEX(jsbytecode *pc, uint32_t index) { pc[1] = (jsbytecode)(index >> 24); pc[2] = (jsbytecode)(index >> 16); pc[3] = (jsbytecode)(index >> 8); pc[4] = (jsbytecode)index; } #define UINT24_HI(i) ((jsbytecode)((i) >> 16)) #define UINT24_MID(i) ((jsbytecode)((i) >> 8)) #define UINT24_LO(i) ((jsbytecode)(i)) #define GET_UINT24(pc) ((jsatomid)(((pc)[1] << 16) | \ ((pc)[2] << 8) | \ (pc)[3])) #define SET_UINT24(pc,i) ((pc)[1] = UINT24_HI(i), \ (pc)[2] = UINT24_MID(i), \ (pc)[3] = UINT24_LO(i)) #define GET_INT8(pc) (int8_t((pc)[1])) #define GET_INT32(pc) (((uint32_t((pc)[1]) << 24) | \ (uint32_t((pc)[2]) << 16) | \ (uint32_t((pc)[3]) << 8) | \ uint32_t((pc)[4]))) #define SET_INT32(pc,i) ((pc)[1] = (jsbytecode)(uint32_t(i) >> 24), \ (pc)[2] = (jsbytecode)(uint32_t(i) >> 16), \ (pc)[3] = (jsbytecode)(uint32_t(i) >> 8), \ (pc)[4] = (jsbytecode)uint32_t(i)) /* Index limit is determined by SN_3BYTE_OFFSET_FLAG, see frontend/BytecodeEmitter.h. */ #define INDEX_LIMIT_LOG2 23 #define INDEX_LIMIT (uint32_t(1) << INDEX_LIMIT_LOG2) /* Actual argument count operand format helpers. */ #define ARGC_HI(argc) UINT16_HI(argc) #define ARGC_LO(argc) UINT16_LO(argc) #define GET_ARGC(pc) GET_UINT16(pc) #define ARGC_LIMIT UINT16_LIMIT /* Synonyms for quick JOF_QARG and JOF_LOCAL bytecodes. */ #define GET_ARGNO(pc) GET_UINT16(pc) #define SET_ARGNO(pc,argno) SET_UINT16(pc,argno) #define ARGNO_LEN 2 #define ARGNO_LIMIT UINT16_LIMIT #define GET_SLOTNO(pc) GET_UINT16(pc) #define SET_SLOTNO(pc,varno) SET_UINT16(pc,varno) #define SLOTNO_LEN 2 #define SLOTNO_LIMIT UINT16_LIMIT struct JSCodeSpec { int8_t length; /* length including opcode byte */ int8_t nuses; /* arity, -1 if variadic */ int8_t ndefs; /* number of stack results */ uint32_t format; /* immediate operand format */ uint32_t type() const { return JOF_TYPE(format); } }; extern const JSCodeSpec js_CodeSpec[]; extern const unsigned js_NumCodeSpecs; extern const char * const js_CodeName[]; extern const char js_EscapeMap[]; /* Silence unreferenced formal parameter warnings */ #ifdef _MSC_VER #pragma warning(push) #pragma warning(disable:4100) #endif /* * Return a GC'ed string containing the chars in str, with any non-printing * chars or quotes (' or " as specified by the quote argument) escaped, and * with the quote character at the beginning and end of the result string. */ extern JSString * js_QuoteString(JSContext *cx, JSString *str, jschar quote); namespace js { extern unsigned StackUses(JSScript *script, jsbytecode *pc); extern unsigned StackDefs(JSScript *script, jsbytecode *pc); } /* namespace js */ /* * Given bytecode address pc in script's main program code, return the operand * stack depth just before (JSOp) *pc executes. */ extern unsigned js_ReconstructStackDepth(JSContext *cx, JSScript *script, jsbytecode *pc); #ifdef _MSC_VER #pragma warning(pop) #endif #define JSDVG_IGNORE_STACK 0 #define JSDVG_SEARCH_STACK 1 /* * Get the length of variable-length bytecode like JSOP_TABLESWITCH. */ extern size_t js_GetVariableBytecodeLength(jsbytecode *pc); namespace js { /* * Find the source expression that resulted in v, and return a newly allocated * C-string containing it. Fall back on v's string conversion (fallback) if we * can't find the bytecode that generated and pushed v on the operand stack. * * Search the current stack frame if spindex is JSDVG_SEARCH_STACK. Don't * look for v on the stack if spindex is JSDVG_IGNORE_STACK. Otherwise, * spindex is the negative index of v, measured from cx->fp->sp, or from a * lower frame's sp if cx->fp is native. * * The optional argument skipStackHits can be used to skip a hit in the stack * frame. This can be useful in self-hosted code that wants to report value * errors containing decompiled values that are useful for the user, instead of * values used internally by the self-hosted code. * * The caller must call JS_free on the result after a successful call. */ char * DecompileValueGenerator(JSContext *cx, int spindex, HandleValue v, HandleString fallback, int skipStackHits = 0); /* * Decompile the formal argument at formalIndex in the nearest non-builtin * stack frame, falling back with converting v to source. */ char * DecompileArgument(JSContext *cx, int formalIndex, HandleValue v); /* * Sprintf, but with unlimited and automatically allocated buffering. */ class Sprinter { public: struct InvariantChecker { const Sprinter *parent; explicit InvariantChecker(const Sprinter *p) : parent(p) { parent->checkInvariants(); } ~InvariantChecker() { parent->checkInvariants(); } }; JSContext *context; /* context executing the decompiler */ private: static const size_t DefaultSize; #ifdef DEBUG bool initialized; /* true if this is initialized, use for debug builds */ #endif char *base; /* malloc'd buffer address */ size_t size; /* size of buffer allocated at base */ ptrdiff_t offset; /* offset of next free char in buffer */ bool reportedOOM; /* this sprinter has reported OOM in string ops */ bool realloc_(size_t newSize); public: explicit Sprinter(JSContext *cx); ~Sprinter(); /* Initialize this sprinter, returns false on error */ bool init(); void checkInvariants() const; const char *string() const; const char *stringEnd() const; /* Returns the string at offset |off| */ char *stringAt(ptrdiff_t off) const; /* Returns the char at offset |off| */ char &operator[](size_t off); /* Test if this Sprinter is empty */ bool empty() const; /* * Attempt to reserve len + 1 space (for a trailing NULL byte). If the * attempt succeeds, return a pointer to the start of that space and adjust the * internal content. The caller *must* completely fill this space on success. */ char *reserve(size_t len); /* Like reserve, but memory is initialized to 0 */ char *reserveAndClear(size_t len); /* * Puts |len| characters from |s| at the current position and return an offset to * the beginning of this new data */ ptrdiff_t put(const char *s, size_t len); ptrdiff_t put(const char *s); ptrdiff_t putString(JSString *str); /* Prints a formatted string into the buffer */ int printf(const char *fmt, ...); /* Change the offset */ void setOffset(const char *end); void setOffset(ptrdiff_t off); /* Get the offset */ ptrdiff_t getOffset() const; ptrdiff_t getOffsetOf(const char *string) const; /* * Report that a string operation failed to get the memory it requested. The * first call to this function calls JS_ReportOutOfMemory, and sets this * Sprinter's outOfMemory flag; subsequent calls do nothing. */ void reportOutOfMemory(); /* Return true if this Sprinter ran out of memory. */ bool hadOutOfMemory() const; }; extern ptrdiff_t Sprint(Sprinter *sp, const char *format, ...); extern bool CallResultEscapes(jsbytecode *pc); static inline unsigned GetDecomposeLength(jsbytecode *pc, size_t len) { /* * The last byte of a DECOMPOSE op stores the decomposed length. This is a * constant: perhaps we should just hardcode values instead? */ JS_ASSERT(size_t(js_CodeSpec[*pc].length) == len); return (unsigned) pc[len - 1]; } static inline unsigned GetBytecodeLength(jsbytecode *pc) { JSOp op = (JSOp)*pc; JS_ASSERT(op < JSOP_LIMIT); if (js_CodeSpec[op].length != -1) return js_CodeSpec[op].length; return js_GetVariableBytecodeLength(pc); } static inline bool BytecodeIsPopped(jsbytecode *pc) { jsbytecode *next = pc + GetBytecodeLength(pc); return JSOp(*next) == JSOP_POP; } static inline bool BytecodeFlowsToBitop(jsbytecode *pc) { // Look for simple bytecode for integer conversions like (x | 0) or (x & -1). jsbytecode *next = pc + GetBytecodeLength(pc); if (*next == JSOP_BITOR || *next == JSOP_BITAND) return true; if (*next == JSOP_INT8 && GET_INT8(next) == -1) { next += GetBytecodeLength(next); if (*next == JSOP_BITAND) return true; return false; } if (*next == JSOP_ONE) { next += GetBytecodeLength(next); if (*next == JSOP_NEG) { next += GetBytecodeLength(next); if (*next == JSOP_BITAND) return true; } return false; } if (*next == JSOP_ZERO) { next += GetBytecodeLength(next); if (*next == JSOP_BITOR) return true; return false; } return false; } extern bool IsValidBytecodeOffset(JSContext *cx, JSScript *script, size_t offset); inline bool FlowsIntoNext(JSOp op) { /* JSOP_YIELD is considered to flow into the next instruction, like JSOP_CALL. */ return op != JSOP_STOP && op != JSOP_RETURN && op != JSOP_RETRVAL && op != JSOP_THROW && op != JSOP_GOTO && op != JSOP_RETSUB; } inline bool IsArgOp(JSOp op) { return JOF_OPTYPE(op) == JOF_QARG; } inline bool IsLocalOp(JSOp op) { return JOF_OPTYPE(op) == JOF_LOCAL; } inline bool IsAliasedVarOp(JSOp op) { return JOF_OPTYPE(op) == JOF_SCOPECOORD; } inline bool IsGlobalOp(JSOp op) { return js_CodeSpec[op].format & JOF_GNAME; } inline bool IsEqualityOp(JSOp op) { return op == JSOP_EQ || op == JSOP_NE || op == JSOP_STRICTEQ || op == JSOP_STRICTNE; } inline bool IsGetterPC(jsbytecode *pc) { JSOp op = JSOp(*pc); return op == JSOP_LENGTH || op == JSOP_GETPROP || op == JSOP_CALLPROP; } inline bool IsSetterPC(jsbytecode *pc) { JSOp op = JSOp(*pc); return op == JSOP_SETPROP || op == JSOP_SETNAME || op == JSOP_SETGNAME; } static inline int32_t GetBytecodeInteger(jsbytecode *pc) { switch (JSOp(*pc)) { case JSOP_ZERO: return 0; case JSOP_ONE: return 1; case JSOP_UINT16: return GET_UINT16(pc); case JSOP_UINT24: return GET_UINT24(pc); case JSOP_INT8: return GET_INT8(pc); case JSOP_INT32: return GET_INT32(pc); default: JS_NOT_REACHED("Bad op"); return 0; } } /* * Counts accumulated for a single opcode in a script. The counts tracked vary * between opcodes, and this structure ensures that counts are accessed in a * coherent fashion. */ class PCCounts { friend class ::JSScript; double *counts; #ifdef DEBUG size_t capacity; #elif JS_BITS_PER_WORD == 32 void *padding; #endif public: enum BaseCounts { BASE_INTERP = 0, BASE_METHODJIT, BASE_METHODJIT_STUBS, BASE_METHODJIT_CODE, BASE_METHODJIT_PICS, BASE_LIMIT }; enum AccessCounts { ACCESS_MONOMORPHIC = BASE_LIMIT, ACCESS_DIMORPHIC, ACCESS_POLYMORPHIC, ACCESS_BARRIER, ACCESS_NOBARRIER, ACCESS_UNDEFINED, ACCESS_NULL, ACCESS_BOOLEAN, ACCESS_INT32, ACCESS_DOUBLE, ACCESS_STRING, ACCESS_OBJECT, ACCESS_LIMIT }; static bool accessOp(JSOp op) { /* * Access ops include all name, element and property reads, as well as * SETELEM and SETPROP (for ElementCounts/PropertyCounts alignment). */ if (op == JSOP_SETELEM || op == JSOP_SETPROP) return true; int format = js_CodeSpec[op].format; return !!(format & (JOF_NAME | JOF_GNAME | JOF_ELEM | JOF_PROP)) && !(format & JOF_SET); } enum ElementCounts { ELEM_ID_INT = ACCESS_LIMIT, ELEM_ID_DOUBLE, ELEM_ID_OTHER, ELEM_ID_UNKNOWN, ELEM_OBJECT_TYPED, ELEM_OBJECT_PACKED, ELEM_OBJECT_DENSE, ELEM_OBJECT_OTHER, ELEM_LIMIT }; static bool elementOp(JSOp op) { return accessOp(op) && (JOF_MODE(js_CodeSpec[op].format) == JOF_ELEM); } enum PropertyCounts { PROP_STATIC = ACCESS_LIMIT, PROP_DEFINITE, PROP_OTHER, PROP_LIMIT }; static bool propertyOp(JSOp op) { return accessOp(op) && (JOF_MODE(js_CodeSpec[op].format) == JOF_PROP); } enum ArithCounts { ARITH_INT = BASE_LIMIT, ARITH_DOUBLE, ARITH_OTHER, ARITH_UNKNOWN, ARITH_LIMIT }; static bool arithOp(JSOp op) { return !!(js_CodeSpec[op].format & JOF_ARITH); } static size_t numCounts(JSOp op) { if (accessOp(op)) { if (elementOp(op)) return ELEM_LIMIT; if (propertyOp(op)) return PROP_LIMIT; return ACCESS_LIMIT; } if (arithOp(op)) return ARITH_LIMIT; return BASE_LIMIT; } static const char *countName(JSOp op, size_t which); double *rawCounts() const { return counts; } double& get(size_t which) { JS_ASSERT(which < capacity); return counts[which]; } /* Boolean conversion, for 'if (counters) ...' */ operator void*() const { return counts; } }; /* Necessary for alignment with the script. */ JS_STATIC_ASSERT(sizeof(PCCounts) % sizeof(Value) == 0); static inline jsbytecode * GetNextPc(jsbytecode *pc) { return pc + js_CodeSpec[JSOp(*pc)].length; } } /* namespace js */ #if defined(DEBUG) /* * Disassemblers, for debugging only. */ JSBool js_Disassemble(JSContext *cx, JS::Handle script, JSBool lines, js::Sprinter *sp); unsigned js_Disassemble1(JSContext *cx, JS::Handle script, jsbytecode *pc, unsigned loc, JSBool lines, js::Sprinter *sp); void js_DumpPCCounts(JSContext *cx, JS::Handle script, js::Sprinter *sp); #ifdef JS_ION namespace js { namespace jit { struct IonScriptCounts; } void DumpIonScriptCounts(js::Sprinter *sp, jit::IonScriptCounts *ionCounts); } #endif #endif #endif /* jsopcode_h */