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/* -*- 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 <stddef.h>
#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<JSScript*> script, JSBool lines, js::Sprinter *sp);
unsigned
js_Disassemble1(JSContext *cx, JS::Handle<JSScript*> script, jsbytecode *pc, unsigned loc,
JSBool lines, js::Sprinter *sp);
void
js_DumpPCCounts(JSContext *cx, JS::Handle<JSScript*> 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 */