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gecko-dev/js/src/jsopcode.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set sw=4 ts=8 et tw=99:
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* JS bytecode descriptors, disassemblers, and decompilers.
*/
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "jstypes.h"
#include "jsstdint.h"
#include "jsarena.h"
#include "jsutil.h"
#include "jsprf.h"
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsversion.h"
#include "jsemit.h"
#include "jsfun.h"
#include "jsiter.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsregexp.h"
#include "jsscan.h"
#include "jsscope.h"
#include "jsscript.h"
#include "jsstr.h"
#include "jsstaticcheck.h"
#include "jsvector.h"
#include "jscntxtinlines.h"
#include "jsobjinlines.h"
#include "jsopcodeinlines.h"
#include "jsscriptinlines.h"
#include "jsautooplen.h"
using namespace js;
using namespace js::gc;
/*
* Index limit must stay within 32 bits.
*/
JS_STATIC_ASSERT(sizeof(uint32) * JS_BITS_PER_BYTE >= INDEX_LIMIT_LOG2 + 1);
/* Verify JSOP_XXX_LENGTH constant definitions. */
#define OPDEF(op,val,name,token,length,nuses,ndefs,prec,format) \
JS_STATIC_ASSERT(op##_LENGTH == length);
#include "jsopcode.tbl"
#undef OPDEF
static const char js_incop_strs[][3] = {"++", "--"};
static const char js_for_each_str[] = "for each";
const JSCodeSpec js_CodeSpec[] = {
#define OPDEF(op,val,name,token,length,nuses,ndefs,prec,format) \
{length,nuses,ndefs,prec,format},
#include "jsopcode.tbl"
#undef OPDEF
};
uintN js_NumCodeSpecs = JS_ARRAY_LENGTH(js_CodeSpec);
/*
* Each element of the array is either a source literal associated with JS
* bytecode or null.
*/
static const char *CodeToken[] = {
#define OPDEF(op,val,name,token,length,nuses,ndefs,prec,format) \
token,
#include "jsopcode.tbl"
#undef OPDEF
};
#if defined(DEBUG) || defined(JS_JIT_SPEW) || defined(JS_METHODJIT_SPEW)
/*
* Array of JS bytecode names used by DEBUG-only js_Disassemble and by
* JIT debug spew.
*/
const char *js_CodeName[] = {
#define OPDEF(op,val,name,token,length,nuses,ndefs,prec,format) \
name,
#include "jsopcode.tbl"
#undef OPDEF
};
#endif
/************************************************************************/
#define COUNTS_LEN 16
static ptrdiff_t
GetJumpOffset(jsbytecode *pc, jsbytecode *pc2)
{
uint32 type;
type = JOF_OPTYPE(*pc);
if (JOF_TYPE_IS_EXTENDED_JUMP(type))
return GET_JUMPX_OFFSET(pc2);
return GET_JUMP_OFFSET(pc2);
}
uintN
js_GetIndexFromBytecode(JSContext *cx, JSScript *script, jsbytecode *pc,
ptrdiff_t pcoff)
{
JSOp op;
uintN span, base;
op = js_GetOpcode(cx, script, pc);
JS_ASSERT(js_CodeSpec[op].length >= 1 + pcoff + UINT16_LEN);
/*
* We need to detect index base prefix. It presents when resetbase
* follows the bytecode.
*/
span = js_CodeSpec[op].length;
base = 0;
if (pc - script->code + span < script->length) {
if (pc[span] == JSOP_RESETBASE) {
base = GET_INDEXBASE(pc - JSOP_INDEXBASE_LENGTH);
} else if (pc[span] == JSOP_RESETBASE0) {
JS_ASSERT(JSOP_INDEXBASE1 <= pc[-1] || pc[-1] <= JSOP_INDEXBASE3);
base = (pc[-1] - JSOP_INDEXBASE1 + 1) << 16;
}
}
return base + GET_UINT16(pc + pcoff);
}
size_t
js_GetVariableBytecodeLength(JSOp op, jsbytecode *pc)
{
uintN jmplen, ncases;
jsint low, high;
JS_ASSERT(js_CodeSpec[op].length == -1);
switch (op) {
case JSOP_TABLESWITCHX:
jmplen = JUMPX_OFFSET_LEN;
goto do_table;
case JSOP_TABLESWITCH:
jmplen = JUMP_OFFSET_LEN;
do_table:
/* Structure: default-jump case-low case-high case1-jump ... */
pc += jmplen;
low = GET_JUMP_OFFSET(pc);
pc += JUMP_OFFSET_LEN;
high = GET_JUMP_OFFSET(pc);
ncases = (uintN)(high - low + 1);
return 1 + jmplen + INDEX_LEN + INDEX_LEN + ncases * jmplen;
case JSOP_LOOKUPSWITCHX:
jmplen = JUMPX_OFFSET_LEN;
goto do_lookup;
default:
JS_ASSERT(op == JSOP_LOOKUPSWITCH);
jmplen = JUMP_OFFSET_LEN;
do_lookup:
/* Structure: default-jump case-count (case1-value case1-jump) ... */
pc += jmplen;
ncases = GET_UINT16(pc);
return 1 + jmplen + INDEX_LEN + ncases * (INDEX_LEN + jmplen);
}
}
uintN
js_GetVariableStackUses(JSOp op, jsbytecode *pc)
{
JS_ASSERT(*pc == op || *pc == JSOP_TRAP);
JS_ASSERT(js_CodeSpec[op].nuses == -1);
switch (op) {
case JSOP_POPN:
return GET_UINT16(pc);
case JSOP_LEAVEBLOCK:
return GET_UINT16(pc);
case JSOP_LEAVEBLOCKEXPR:
return GET_UINT16(pc) + 1;
default:
/* stack: fun, this, [argc arguments] */
JS_ASSERT(op == JSOP_NEW || op == JSOP_CALL || op == JSOP_EVAL ||
op == JSOP_FUNCALL || op == JSOP_FUNAPPLY);
return 2 + GET_ARGC(pc);
}
}
uintN
js_GetEnterBlockStackDefs(JSContext *cx, JSScript *script, jsbytecode *pc)
{
JSObject *obj;
JS_ASSERT(*pc == JSOP_ENTERBLOCK || *pc == JSOP_TRAP);
GET_OBJECT_FROM_BYTECODE(script, pc, 0, obj);
return OBJ_BLOCK_COUNT(cx, obj);
}
class AutoScriptUntrapper {
JSContext *cx;
JSScript *script;
jsbytecode *origPC;
jsbytecode *newPC;
#ifdef DEBUG
bool assertionBefore;
#endif
public:
AutoScriptUntrapper(JSContext *cx, JSScript *script, jsbytecode **pc)
: cx(cx), script(script), origPC(*pc)
#ifdef DEBUG
, assertionBefore(false)
#endif
{
jsbytecode *newCode = js_UntrapScriptCode(cx, script);
if (newCode == script->code) {
// No change needed
newPC = origPC;
} else {
*pc = newPC = origPC + (newCode - script->code);
script->code = newCode;
#ifdef DEBUG
assertionBefore = cx->stackIterAssertionEnabled;
cx->stackIterAssertionEnabled = false;
#endif
}
}
~AutoScriptUntrapper()
{
ptrdiff_t delta = newPC - origPC;
if (delta) {
jsbytecode *oldCode = script->code - delta;
cx->free_(script->code);
script->code = oldCode;
#ifdef DEBUG
cx->stackIterAssertionEnabled = assertionBefore;
#endif
}
}
};
#ifdef DEBUG
/*
* If pc != NULL, include a prefix indicating whether the PC is at the current line.
* If counts != NULL, include a counter of the number of times each op was executed.
*/
JS_FRIEND_API(JSBool)
js_DisassembleAtPC(JSContext *cx, JSScript *script, JSBool lines, jsbytecode *pc, Sprinter *sp)
{
jsbytecode *next, *end;
uintN len;
SprintCString(sp, "loc ");
if (script->pcCounters)
Sprint(sp, "counts%*s x ", COUNTS_LEN - strlen("counts"), "");
if (lines)
SprintCString(sp, "line");
SprintCString(sp, " op\n");
SprintCString(sp, "----- ");
if (script->pcCounters) {
for (int i = 0; i < COUNTS_LEN; ++i)
SprintCString(sp, "-");
SprintCString(sp, " ");
}
if (lines)
SprintCString(sp, "----");
SprintCString(sp, " --\n");
next = script->code;
end = next + script->length;
while (next < end) {
if (next == script->main())
SprintCString(sp, "main:\n");
if (pc != NULL) {
if (pc == next)
SprintCString(sp, "--> ");
else
SprintCString(sp, " ");
}
len = js_Disassemble1(cx, script, next,
next - script->code,
lines, sp);
if (!len)
return JS_FALSE;
next += len;
}
return JS_TRUE;
}
JS_FRIEND_API(JSBool)
js_Disassemble(JSContext *cx, JSScript *script, JSBool lines, Sprinter *sp)
{
return js_DisassembleAtPC(cx, script, lines, NULL, sp);
}
JS_FRIEND_API(JSBool)
js_DumpPC(JSContext *cx)
{
void *mark = JS_ARENA_MARK(&cx->tempPool);
Sprinter sprinter;
INIT_SPRINTER(cx, &sprinter, &cx->tempPool, 0);
JSBool ok = js_DisassembleAtPC(cx, cx->fp()->script(), true, cx->regs().pc, &sprinter);
fprintf(stdout, "%s", sprinter.base);
JS_ARENA_RELEASE(&cx->tempPool, mark);
return ok;
}
JSBool
js_DumpScript(JSContext *cx, JSScript *script)
{
void *mark = JS_ARENA_MARK(&cx->tempPool);
Sprinter sprinter;
INIT_SPRINTER(cx, &sprinter, &cx->tempPool, 0);
JSBool ok = js_Disassemble(cx, script, true, &sprinter);
fprintf(stdout, "%s", sprinter.base);
JS_ARENA_RELEASE(&cx->tempPool, mark);
return ok;
}
static bool
ToDisassemblySource(JSContext *cx, jsval v, JSAutoByteString *bytes)
{
if (!JSVAL_IS_PRIMITIVE(v)) {
JSObject *obj = JSVAL_TO_OBJECT(v);
Class *clasp = obj->getClass();
if (clasp == &js_BlockClass) {
char *source = JS_sprintf_append(NULL, "depth %d {", OBJ_BLOCK_DEPTH(cx, obj));
if (!source)
return false;
Shape::Range r = obj->lastProperty()->all();
while (!r.empty()) {
const Shape &shape = r.front();
JSAutoByteString bytes;
if (!js_AtomToPrintableString(cx, JSID_TO_ATOM(shape.propid), &bytes))
return false;
r.popFront();
source = JS_sprintf_append(source, "%s: %d%s",
bytes.ptr(), shape.shortid,
!r.empty() ? ", " : "");
if (!source)
return false;
}
source = JS_sprintf_append(source, "}");
if (!source)
return false;
bytes->initBytes(source);
return true;
}
if (clasp == &js_FunctionClass) {
JSFunction *fun = obj->getFunctionPrivate();
JSString *str = JS_DecompileFunction(cx, fun, JS_DONT_PRETTY_PRINT);
if (!str)
return false;
return bytes->encode(cx, str);
}
if (clasp == &js_RegExpClass) {
AutoValueRooter tvr(cx);
if (!js_regexp_toString(cx, obj, tvr.addr()))
return false;
return bytes->encode(cx, JSVAL_TO_STRING(Jsvalify(tvr.value())));
}
}
return !!js_ValueToPrintable(cx, Valueify(v), bytes, true);
}
JS_FRIEND_API(uintN)
js_Disassemble1(JSContext *cx, JSScript *script, jsbytecode *pc,
uintN loc, JSBool lines, Sprinter *sp)
{
JSOp op;
const JSCodeSpec *cs;
ptrdiff_t len, off, jmplen;
uint32 type;
JSAtom *atom;
uintN index;
JSObject *obj;
jsval v;
jsint i;
JSPCCounters& counts(script->pcCounters);
AutoScriptUntrapper untrapper(cx, script, &pc);
op = (JSOp)*pc;
if (op >= JSOP_LIMIT) {
char numBuf1[12], numBuf2[12];
JS_snprintf(numBuf1, sizeof numBuf1, "%d", op);
JS_snprintf(numBuf2, sizeof numBuf2, "%d", JSOP_LIMIT);
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_BYTECODE_TOO_BIG, numBuf1, numBuf2);
return 0;
}
cs = &js_CodeSpec[op];
len = (ptrdiff_t) cs->length;
Sprint(sp, "%05u:", loc);
if (counts) {
ptrdiff_t start = Sprint(sp, "%.0f", counts.get(0, loc));
for (size_t i = 1; i < JSPCCounters::NUM_COUNTERS; ++i)
Sprint(sp, "/%.0f", counts.get(i, loc));
int l = Sprint(sp, "") - start;
if (l < COUNTS_LEN)
Sprint(sp, "%*s", COUNTS_LEN - l, "");
double mjitHits = counts.get(JSPCCounters::METHODJIT, loc);
if (mjitHits) {
Sprint(sp, " %.0f/%.0f",
counts.get(JSPCCounters::METHODJIT_CODE, loc) / mjitHits,
counts.get(JSPCCounters::METHODJIT_PICS, loc) / mjitHits);
}
Sprint(sp, " x ");
}
if (lines)
Sprint(sp, "%4u", JS_PCToLineNumber(cx, script, pc));
Sprint(sp, " %s", js_CodeName[op]);
type = JOF_TYPE(cs->format);
switch (type) {
case JOF_BYTE:
// Scan the trynotes to find the associated catch block
// and make the try opcode look like a jump instruction
// with an offset. This simplifies code coverage analysis
// based on this disassembled output.
if (op == JSOP_TRY) {
JSTryNoteArray *trynotes = script->trynotes();
uint32 i;
for(i = 0; i < trynotes->length; i++) {
JSTryNote note = trynotes->vector[i];
if (note.kind == JSTRY_CATCH && note.start == loc + 1) {
Sprint(sp, " %u (%+d)",
(unsigned int) (loc+note.length+1),
(int) (note.length+1));
break;
}
}
}
break;
case JOF_JUMP:
case JOF_JUMPX:
off = GetJumpOffset(pc, pc);
Sprint(sp, " %u (%+d)", loc + (intN) off, (intN) off);
break;
case JOF_ATOM:
case JOF_OBJECT:
case JOF_REGEXP:
index = js_GetIndexFromBytecode(cx, script, pc, 0);
if (type == JOF_ATOM) {
if (op == JSOP_DOUBLE) {
v = Jsvalify(script->getConst(index));
} else {
JS_GET_SCRIPT_ATOM(script, pc, index, atom);
v = STRING_TO_JSVAL(atom);
}
} else {
if (type == JOF_OBJECT) {
/* Don't call obj.toSource if analysis/inference is active. */
if (cx->compartment->activeAnalysis) {
Sprint(sp, " object");
break;
}
obj = script->getObject(index);
} else {
obj = script->getRegExp(index);
}
v = OBJECT_TO_JSVAL(obj);
}
{
JSAutoByteString bytes;
if (!ToDisassemblySource(cx, v, &bytes))
return 0;
Sprint(sp, " %s", bytes.ptr());
}
break;
case JOF_GLOBAL:
atom = script->getGlobalAtom(GET_SLOTNO(pc));
v = STRING_TO_JSVAL(atom);
{
JSAutoByteString bytes;
if (!ToDisassemblySource(cx, v, &bytes))
return 0;
Sprint(sp, " %s", bytes.ptr());
}
break;
case JOF_UINT16PAIR:
i = (jsint)GET_UINT16(pc);
Sprint(sp, " %d", i);
pc += UINT16_LEN;
/* FALL THROUGH */
case JOF_UINT16:
i = (jsint)GET_UINT16(pc);
goto print_int;
case JOF_TABLESWITCH:
case JOF_TABLESWITCHX:
{
jsbytecode *pc2;
jsint i, low, high;
jmplen = (type == JOF_TABLESWITCH) ? JUMP_OFFSET_LEN
: JUMPX_OFFSET_LEN;
pc2 = pc;
off = GetJumpOffset(pc, pc2);
pc2 += jmplen;
low = GET_JUMP_OFFSET(pc2);
pc2 += JUMP_OFFSET_LEN;
high = GET_JUMP_OFFSET(pc2);
pc2 += JUMP_OFFSET_LEN;
Sprint(sp, " defaultOffset %d low %d high %d", intN(off), low, high);
for (i = low; i <= high; i++) {
off = GetJumpOffset(pc, pc2);
Sprint(sp, "\n\t%d: %d", i, intN(off));
pc2 += jmplen;
}
len = 1 + pc2 - pc;
break;
}
case JOF_LOOKUPSWITCH:
case JOF_LOOKUPSWITCHX:
{
jsbytecode *pc2;
jsatomid npairs;
jmplen = (type == JOF_LOOKUPSWITCH) ? JUMP_OFFSET_LEN
: JUMPX_OFFSET_LEN;
pc2 = pc;
off = GetJumpOffset(pc, pc2);
pc2 += jmplen;
npairs = GET_UINT16(pc2);
pc2 += UINT16_LEN;
Sprint(sp, " offset %d npairs %u", intN(off), uintN(npairs));
while (npairs) {
uint16 constIndex = GET_INDEX(pc2);
pc2 += INDEX_LEN;
off = GetJumpOffset(pc, pc2);
pc2 += jmplen;
JSAutoByteString bytes;
if (!ToDisassemblySource(cx, Jsvalify(script->getConst(constIndex)), &bytes))
return 0;
Sprint(sp, "\n\t%s: %d", bytes.ptr(), intN(off));
npairs--;
}
len = 1 + pc2 - pc;
break;
}
case JOF_QARG:
Sprint(sp, " %u", GET_ARGNO(pc));
break;
case JOF_LOCAL:
Sprint(sp, " %u", GET_SLOTNO(pc));
break;
case JOF_SLOTATOM:
case JOF_SLOTOBJECT: {
Sprint(sp, " %u", GET_SLOTNO(pc));
index = js_GetIndexFromBytecode(cx, script, pc, SLOTNO_LEN);
if (type == JOF_SLOTATOM) {
JS_GET_SCRIPT_ATOM(script, pc, index, atom);
v = STRING_TO_JSVAL(atom);
} else {
obj = script->getObject(index);
v = OBJECT_TO_JSVAL(obj);
}
JSAutoByteString bytes;
if (!ToDisassemblySource(cx, v, &bytes))
return 0;
Sprint(sp, " %s", bytes.ptr());
break;
}
case JOF_UINT24:
JS_ASSERT(op == JSOP_UINT24 || op == JSOP_NEWARRAY);
i = (jsint)GET_UINT24(pc);
goto print_int;
case JOF_UINT8:
i = pc[1];
goto print_int;
case JOF_INT8:
i = GET_INT8(pc);
goto print_int;
case JOF_INT32:
JS_ASSERT(op == JSOP_INT32);
i = GET_INT32(pc);
print_int:
Sprint(sp, " %d", i);
break;
default: {
char numBuf[12];
JS_snprintf(numBuf, sizeof numBuf, "%lx", (unsigned long) cs->format);
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_UNKNOWN_FORMAT, numBuf);
return 0;
}
}
SprintCString(sp, "\n");
return len;
}
#endif /* DEBUG */
/************************************************************************/
#define OFF2STR(sp,off) ((sp)->base + (off))
#define STR2OFF(sp,str) ((str) - (sp)->base)
#define RETRACT(sp,str) ((sp)->offset = STR2OFF(sp, str))
static JSBool
SprintEnsureBuffer(Sprinter *sp, size_t len)
{
ptrdiff_t nb;
char *base;
nb = (sp->offset + len + 1) - sp->size;
if (nb < 0)
return JS_TRUE;
base = sp->base;
if (!base) {
JS_ARENA_ALLOCATE_CAST(base, char *, sp->pool, nb);
} else {
JS_ARENA_GROW_CAST(base, char *, sp->pool, sp->size, nb);
}
if (!base) {
js_ReportOutOfMemory(sp->context);
return JS_FALSE;
}
sp->base = base;
sp->size += nb;
return JS_TRUE;
}
namespace js {
char *
SprintReserveAmount(Sprinter *sp, size_t len)
{
/* Allocate space for s, including the '\0' at the end. */
if (!SprintEnsureBuffer(sp, len))
return NULL;
/* Advance offset and return the previous offset for caller to fill. */
ptrdiff_t offset = sp->offset;
sp->offset += len;
return sp->base + offset;
}
ptrdiff_t
SprintPut(Sprinter *sp, const char *s, size_t len)
{
ptrdiff_t offset = sp->size; /* save old size */
char *bp = sp->base; /* save old base */
/* Allocate space for s, including the '\0' at the end. */
if (!SprintEnsureBuffer(sp, len))
return -1;
if (sp->base != bp && /* buffer was realloc'ed */
s >= bp && s < bp + offset) { /* s was within the buffer */
s = sp->base + (s - bp); /* this is where it lives now */
}
/* Advance offset and copy s into sp's buffer. */
offset = sp->offset;
sp->offset += len;
bp = sp->base + offset;
memmove(bp, s, len);
bp[len] = 0;
return offset;
}
ptrdiff_t
SprintCString(Sprinter *sp, const char *s)
{
return SprintPut(sp, s, strlen(s));
}
ptrdiff_t
SprintString(Sprinter *sp, JSString *str)
{
size_t length = str->length();
const jschar *chars = str->getChars(sp->context);
if (!chars)
return -1;
size_t size = GetDeflatedStringLength(sp->context, chars, length);
if (size == (size_t)-1 || !SprintEnsureBuffer(sp, size))
return -1;
ptrdiff_t offset = sp->offset;
sp->offset += size;
DeflateStringToBuffer(sp->context, chars, length, sp->base + offset, &size);
sp->base[sp->offset] = 0;
return offset;
}
ptrdiff_t
Sprint(Sprinter *sp, const char *format, ...)
{
va_list ap;
char *bp;
ptrdiff_t offset;
va_start(ap, format);
bp = JS_vsmprintf(format, ap); /* XXX vsaprintf */
va_end(ap);
if (!bp) {
JS_ReportOutOfMemory(sp->context);
return -1;
}
offset = SprintCString(sp, bp);
sp->context->free_(bp);
return offset;
}
} // namespace js
const char js_EscapeMap[] = {
'\b', 'b',
'\f', 'f',
'\n', 'n',
'\r', 'r',
'\t', 't',
'\v', 'v',
'"', '"',
'\'', '\'',
'\\', '\\',
'\0', '0'
};
#define DONT_ESCAPE 0x10000
static char *
QuoteString(Sprinter *sp, JSString *str, uint32 quote)
{
/* Sample off first for later return value pointer computation. */
JSBool dontEscape = (quote & DONT_ESCAPE) != 0;
jschar qc = (jschar) quote;
ptrdiff_t off = sp->offset;
if (qc && Sprint(sp, "%c", (char)qc) < 0)
return NULL;
const jschar *s = str->getChars(sp->context);
if (!s)
return NULL;
const jschar *z = s + str->length();
/* Loop control variables: z points at end of string sentinel. */
for (const jschar *t = s; t < z; s = ++t) {
/* Move t forward from s past un-quote-worthy characters. */
jschar c = *t;
while (c < 127 && isprint(c) && c != qc && c != '\\' && c != '\t') {
c = *++t;
if (t == z)
break;
}
ptrdiff_t len = t - s;
/* Allocate space for s, including the '\0' at the end. */
if (!SprintEnsureBuffer(sp, len))
return NULL;
/* Advance sp->offset and copy s into sp's buffer. */
char *bp = sp->base + sp->offset;
sp->offset += len;
while (--len >= 0)
*bp++ = (char) *s++;
*bp = '\0';
if (t == z)
break;
/* Use js_EscapeMap, \u, or \x only if necessary. */
bool ok;
const char *e;
if (!(c >> 8) && (e = strchr(js_EscapeMap, (int)c)) != NULL) {
ok = dontEscape
? Sprint(sp, "%c", (char)c) >= 0
: Sprint(sp, "\\%c", e[1]) >= 0;
} else {
/*
* Use \x only if the high byte is 0 and we're in a quoted string,
* because ECMA-262 allows only \u, not \x, in Unicode identifiers
* (see bug 621814).
*/
ok = Sprint(sp, (qc && !(c >> 8)) ? "\\x%02X" : "\\u%04X", c) >= 0;
}
if (!ok)
return NULL;
}
/* Sprint the closing quote and return the quoted string. */
if (qc && Sprint(sp, "%c", (char)qc) < 0)
return NULL;
/*
* If we haven't Sprint'd anything yet, Sprint an empty string so that
* the OFF2STR below gives a valid result.
*/
if (off == sp->offset && Sprint(sp, "") < 0)
return NULL;
return OFF2STR(sp, off);
}
JSString *
js_QuoteString(JSContext *cx, JSString *str, jschar quote)
{
void *mark;
Sprinter sprinter;
char *bytes;
JSString *escstr;
mark = JS_ARENA_MARK(&cx->tempPool);
INIT_SPRINTER(cx, &sprinter, &cx->tempPool, 0);
bytes = QuoteString(&sprinter, str, quote);
escstr = bytes ? JS_NewStringCopyZ(cx, bytes) : NULL;
JS_ARENA_RELEASE(&cx->tempPool, mark);
return escstr;
}
/************************************************************************/
struct JSPrinter {
Sprinter sprinter; /* base class state */
JSArenaPool pool; /* string allocation pool */
uintN indent; /* indentation in spaces */
bool pretty; /* pretty-print: indent, use newlines */
bool grouped; /* in parenthesized expression context */
bool strict; /* in code marked strict */
JSScript *script; /* script being printed */
jsbytecode *dvgfence; /* DecompileExpression fencepost */
jsbytecode **pcstack; /* DecompileExpression modeled stack */
JSFunction *fun; /* interpreted function */
Vector<JSAtom *> *localNames; /* argument and variable names */
};
JSPrinter *
js_NewPrinter(JSContext *cx, const char *name, JSFunction *fun,
uintN indent, JSBool pretty, JSBool grouped, JSBool strict)
{
JSPrinter *jp;
jp = (JSPrinter *) cx->malloc_(sizeof(JSPrinter));
if (!jp)
return NULL;
INIT_SPRINTER(cx, &jp->sprinter, &jp->pool, 0);
JS_InitArenaPool(&jp->pool, name, 256, 1);
jp->indent = indent;
jp->pretty = !!pretty;
jp->grouped = !!grouped;
jp->strict = !!strict;
jp->script = NULL;
jp->dvgfence = NULL;
jp->pcstack = NULL;
jp->fun = fun;
jp->localNames = NULL;
if (fun && fun->isInterpreted() && fun->script()->bindings.hasLocalNames()) {
jp->localNames = cx->new_<Vector<JSAtom *> >(cx);
if (!jp->localNames || !fun->script()->bindings.getLocalNameArray(cx, jp->localNames)) {
js_DestroyPrinter(jp);
return NULL;
}
}
return jp;
}
void
js_DestroyPrinter(JSPrinter *jp)
{
JS_FinishArenaPool(&jp->pool);
Foreground::delete_(jp->localNames);
jp->sprinter.context->free_(jp);
}
JSString *
js_GetPrinterOutput(JSPrinter *jp)
{
JSContext *cx;
JSString *str;
cx = jp->sprinter.context;
if (!jp->sprinter.base)
return cx->runtime->emptyString;
str = JS_NewStringCopyZ(cx, jp->sprinter.base);
if (!str)
return NULL;
JS_FreeArenaPool(&jp->pool);
INIT_SPRINTER(cx, &jp->sprinter, &jp->pool, 0);
return str;
}
/*
* NB: Indexed by SRC_DECL_* defines from jsemit.h.
*/
static const char * const var_prefix[] = {"var ", "const ", "let "};
static const char *
VarPrefix(jssrcnote *sn)
{
if (sn && (SN_TYPE(sn) == SRC_DECL || SN_TYPE(sn) == SRC_GROUPASSIGN)) {
ptrdiff_t type = js_GetSrcNoteOffset(sn, 0);
if ((uintN)type <= SRC_DECL_LET)
return var_prefix[type];
}
return "";
}
int
js_printf(JSPrinter *jp, const char *format, ...)
{
va_list ap;
char *bp, *fp;
int cc;
if (*format == '\0')
return 0;
va_start(ap, format);
/* If pretty-printing, expand magic tab into a run of jp->indent spaces. */
if (*format == '\t') {
format++;
if (jp->pretty && Sprint(&jp->sprinter, "%*s", jp->indent, "") < 0) {
va_end(ap);
return -1;
}
}
/* Suppress newlines (must be once per format, at the end) if not pretty. */
fp = NULL;
if (!jp->pretty && format[cc = strlen(format) - 1] == '\n') {
fp = JS_strdup(jp->sprinter.context, format);
if (!fp) {
va_end(ap);
return -1;
}
fp[cc] = '\0';
format = fp;
}
/* Allocate temp space, convert format, and put. */
bp = JS_vsmprintf(format, ap); /* XXX vsaprintf */
if (fp) {
jp->sprinter.context->free_(fp);
format = NULL;
}
if (!bp) {
JS_ReportOutOfMemory(jp->sprinter.context);
va_end(ap);
return -1;
}
cc = strlen(bp);
if (SprintPut(&jp->sprinter, bp, (size_t)cc) < 0)
cc = -1;
jp->sprinter.context->free_(bp);
va_end(ap);
return cc;
}
JSBool
js_puts(JSPrinter *jp, const char *s)
{
return SprintCString(&jp->sprinter, s) >= 0;
}
/************************************************************************/
typedef struct SprintStack {
Sprinter sprinter; /* sprinter for postfix to infix buffering */
ptrdiff_t *offsets; /* stack of postfix string offsets */
jsbytecode *opcodes; /* parallel stack of JS opcodes */
uintN top; /* top of stack index */
uintN inArrayInit; /* array initialiser/comprehension level */
JSBool inGenExp; /* in generator expression */
JSPrinter *printer; /* permanent output goes here */
} SprintStack;
/*
* Find the depth of the operand stack when the interpreter reaches the given
* pc in script. pcstack must have space for least script->depth elements. On
* return it will contain pointers to opcodes that populated the interpreter's
* current operand stack.
*
* This function cannot raise an exception or error. However, due to a risk of
* potential bugs when modeling the stack, the function returns -1 if it
* detects an inconsistency in the model. Such an inconsistency triggers an
* assert in a debug build.
*/
static intN
ReconstructPCStack(JSContext *cx, JSScript *script, jsbytecode *pc,
jsbytecode **pcstack);
#define FAILED_EXPRESSION_DECOMPILER ((char *) 1)
/*
* Decompile a part of expression up to the given pc. The function returns
* NULL on out-of-memory, or the FAILED_EXPRESSION_DECOMPILER sentinel when
* the decompiler fails due to a bug and/or unimplemented feature, or the
* decompiled string on success.
*/
static char *
DecompileExpression(JSContext *cx, JSScript *script, JSFunction *fun,
jsbytecode *pc);
/*
* Get a stacked offset from ss->sprinter.base, or if the stacked value |off|
* is negative, fetch the generating pc from printer->pcstack[-2 - off] and
* decompile the code that generated the missing value. This is used when
* reporting errors, where the model stack will lack |pcdepth| non-negative
* offsets (see DecompileExpression and DecompileCode).
*
* If the stacked offset is -1, return 0 to index the NUL padding at the start
* of ss->sprinter.base. If this happens, it means there is a decompiler bug
* to fix, but it won't violate memory safety.
*/
static ptrdiff_t
GetOff(SprintStack *ss, uintN i)
{
ptrdiff_t off;
jsbytecode *pc;
char *bytes;
off = ss->offsets[i];
if (off >= 0)
return off;
JS_ASSERT(off <= -2);
JS_ASSERT(ss->printer->pcstack);
if (off <= -2 && ss->printer->pcstack) {
pc = ss->printer->pcstack[-2 - off];
bytes = DecompileExpression(ss->sprinter.context, ss->printer->script,
ss->printer->fun, pc);
if (!bytes)
return 0;
if (bytes != FAILED_EXPRESSION_DECOMPILER) {
off = SprintCString(&ss->sprinter, bytes);
if (off < 0)
off = 0;
ss->offsets[i] = off;
ss->sprinter.context->free_(bytes);
return off;
}
if (!ss->sprinter.base && SprintPut(&ss->sprinter, "", 0) >= 0) {
memset(ss->sprinter.base, 0, ss->sprinter.offset);
ss->offsets[i] = -1;
}
}
return 0;
}
static const char *
GetStr(SprintStack *ss, uintN i)
{
ptrdiff_t off;
/*
* Must call GetOff before using ss->sprinter.base, since it may be null
* until bootstrapped by GetOff.
*/
off = GetOff(ss, i);
return OFF2STR(&ss->sprinter, off);
}
/*
* Gap between stacked strings to allow for insertion of parens and commas
* when auto-parenthesizing expressions and decompiling array initialisers.
*/
#define PAREN_SLOP (2 + 1)
/* Fake opcodes (see jsopcode.h) must not overflow unsigned 8-bit space. */
JS_STATIC_ASSERT(JSOP_FAKE_LIMIT <= 255);
static void
AddParenSlop(SprintStack *ss)
{
memset(OFF2STR(&ss->sprinter, ss->sprinter.offset), 0, PAREN_SLOP);
ss->sprinter.offset += PAREN_SLOP;
}
static JSBool
PushOff(SprintStack *ss, ptrdiff_t off, JSOp op)
{
uintN top;
if (!SprintEnsureBuffer(&ss->sprinter, PAREN_SLOP))
return JS_FALSE;
/* ss->top points to the next free slot; be paranoid about overflow. */
top = ss->top;
JS_ASSERT(top < StackDepth(ss->printer->script));
if (top >= StackDepth(ss->printer->script)) {
JS_ReportOutOfMemory(ss->sprinter.context);
return JS_FALSE;
}
/* The opcodes stack must contain real bytecodes that index js_CodeSpec. */
ss->offsets[top] = off;
ss->opcodes[top] = jsbytecode((op == JSOP_GETPROP2) ? JSOP_GETPROP
: (op == JSOP_GETELEM2) ? JSOP_GETELEM
: op);
ss->top = ++top;
AddParenSlop(ss);
return JS_TRUE;
}
static ptrdiff_t
PopOffPrec(SprintStack *ss, uint8 prec)
{
uintN top;
const JSCodeSpec *topcs;
ptrdiff_t off;
/* ss->top points to the next free slot; be paranoid about underflow. */
top = ss->top;
JS_ASSERT(top != 0);
if (top == 0)
return 0;
ss->top = --top;
off = GetOff(ss, top);
topcs = &js_CodeSpec[ss->opcodes[top]];
if (topcs->prec != 0 && topcs->prec < prec) {
ss->sprinter.offset = ss->offsets[top] = off - 2;
off = Sprint(&ss->sprinter, "(%s)", OFF2STR(&ss->sprinter, off));
} else {
ss->sprinter.offset = off;
}
return off;
}
static const char *
PopStrPrec(SprintStack *ss, uint8 prec)
{
ptrdiff_t off;
off = PopOffPrec(ss, prec);
return OFF2STR(&ss->sprinter, off);
}
static ptrdiff_t
PopOff(SprintStack *ss, JSOp op)
{
return PopOffPrec(ss, js_CodeSpec[op].prec);
}
static const char *
PopStr(SprintStack *ss, JSOp op)
{
return PopStrPrec(ss, js_CodeSpec[op].prec);
}
static inline bool
IsInitializerOp(unsigned char op)
{
return op == JSOP_NEWINIT || op == JSOP_NEWARRAY || op == JSOP_NEWOBJECT;
}
typedef struct TableEntry {
jsval key;
ptrdiff_t offset;
JSAtom *label;
jsint order; /* source order for stable tableswitch sort */
} TableEntry;
static JSBool
CompareOffsets(void *arg, const void *v1, const void *v2, int *result)
{
ptrdiff_t offset_diff;
const TableEntry *te1 = (const TableEntry *) v1,
*te2 = (const TableEntry *) v2;
offset_diff = te1->offset - te2->offset;
*result = (offset_diff == 0 ? te1->order - te2->order
: offset_diff < 0 ? -1
: 1);
return JS_TRUE;
}
static ptrdiff_t
SprintDoubleValue(Sprinter *sp, jsval v, JSOp *opp)
{
jsdouble d;
ptrdiff_t todo;
char *s;
JS_ASSERT(JSVAL_IS_DOUBLE(v));
d = JSVAL_TO_DOUBLE(v);
if (JSDOUBLE_IS_NEGZERO(d)) {
todo = SprintCString(sp, "-0");
*opp = JSOP_NEG;
} else if (!JSDOUBLE_IS_FINITE(d)) {
/* Don't use Infinity and NaN, they're mutable. */
todo = SprintCString(sp,
JSDOUBLE_IS_NaN(d)
? "0 / 0"
: (d < 0)
? "1 / -0"
: "1 / 0");
*opp = JSOP_DIV;
} else {
ToCStringBuf cbuf;
s = NumberToCString(sp->context, &cbuf, d);
if (!s) {
JS_ReportOutOfMemory(sp->context);
return -1;
}
JS_ASSERT(strcmp(s, js_Infinity_str) &&
(*s != '-' ||
strcmp(s + 1, js_Infinity_str)) &&
strcmp(s, js_NaN_str));
todo = Sprint(sp, s);
}
return todo;
}
static jsbytecode *
Decompile(SprintStack *ss, jsbytecode *pc, intN nb, JSOp nextop);
static JSBool
DecompileSwitch(SprintStack *ss, TableEntry *table, uintN tableLength,
jsbytecode *pc, ptrdiff_t switchLength,
ptrdiff_t defaultOffset, JSBool isCondSwitch)
{
JSContext *cx;
JSPrinter *jp;
ptrdiff_t off, off2, diff, caseExprOff, todo;
char *lval, *rval;
uintN i;
jsval key;
JSString *str;
cx = ss->sprinter.context;
jp = ss->printer;
/* JSOP_CONDSWITCH doesn't pop, unlike JSOP_{LOOKUP,TABLE}SWITCH. */
off = isCondSwitch ? GetOff(ss, ss->top-1) : PopOff(ss, JSOP_NOP);
lval = OFF2STR(&ss->sprinter, off);
js_printf(jp, "\tswitch (%s) {\n", lval);
if (tableLength) {
diff = table[0].offset - defaultOffset;
if (diff > 0) {
jp->indent += 2;
js_printf(jp, "\t%s:\n", js_default_str);
jp->indent += 2;
if (!Decompile(ss, pc + defaultOffset, diff, JSOP_NOP))
return JS_FALSE;
jp->indent -= 4;
}
caseExprOff = isCondSwitch ? JSOP_CONDSWITCH_LENGTH : 0;
for (i = 0; i < tableLength; i++) {
off = table[i].offset;
off2 = (i + 1 < tableLength) ? table[i + 1].offset : switchLength;
key = table[i].key;
if (isCondSwitch) {
ptrdiff_t nextCaseExprOff;
/*
* key encodes the JSOP_CASE bytecode's offset from switchtop.
* The next case expression follows immediately, unless we are
* at the last case.
*/
nextCaseExprOff = (ptrdiff_t)JSVAL_TO_INT(key);
nextCaseExprOff += js_CodeSpec[pc[nextCaseExprOff]].length;
jp->indent += 2;
if (!Decompile(ss, pc + caseExprOff,
nextCaseExprOff - caseExprOff, JSOP_NOP)) {
return JS_FALSE;
}
caseExprOff = nextCaseExprOff;
/* Balance the stack as if this JSOP_CASE matched. */
--ss->top;
} else {
/*
* key comes from an atom, not the decompiler, so we need to
* quote it if it's a string literal. But if table[i].label
* is non-null, key was constant-propagated and label is the
* name of the const we should show as the case label. We set
* key to undefined so this identifier is escaped, if required
* by non-ASCII characters, but not quoted, by QuoteString.
*/
todo = -1;
if (table[i].label) {
str = table[i].label;
key = JSVAL_VOID;
} else if (JSVAL_IS_DOUBLE(key)) {
JSOp junk;
todo = SprintDoubleValue(&ss->sprinter, key, &junk);
if (todo < 0)
return JS_FALSE;
str = NULL;
} else {
str = js_ValueToString(cx, Valueify(key));
if (!str)
return JS_FALSE;
}
if (todo >= 0) {
rval = OFF2STR(&ss->sprinter, todo);
} else {
rval = QuoteString(&ss->sprinter, str, (jschar)
(JSVAL_IS_STRING(key) ? '"' : 0));
if (!rval)
return JS_FALSE;
}
RETRACT(&ss->sprinter, rval);
jp->indent += 2;
js_printf(jp, "\tcase %s:\n", rval);
}
jp->indent += 2;
if (off <= defaultOffset && defaultOffset < off2) {
diff = defaultOffset - off;
if (diff != 0) {
if (!Decompile(ss, pc + off, diff, JSOP_NOP))
return JS_FALSE;
off = defaultOffset;
}
jp->indent -= 2;
js_printf(jp, "\t%s:\n", js_default_str);
jp->indent += 2;
}
if (!Decompile(ss, pc + off, off2 - off, JSOP_NOP))
return JS_FALSE;
jp->indent -= 4;
/* Re-balance as if last JSOP_CASE or JSOP_DEFAULT mismatched. */
if (isCondSwitch)
++ss->top;
}
}
if (defaultOffset == switchLength) {
jp->indent += 2;
js_printf(jp, "\t%s:;\n", js_default_str);
jp->indent -= 2;
}
js_printf(jp, "\t}\n");
/* By the end of a JSOP_CONDSWITCH, the discriminant has been popped. */
if (isCondSwitch)
--ss->top;
return JS_TRUE;
}
#define LOCAL_ASSERT_CUSTOM(expr, BAD_EXIT) \
JS_BEGIN_MACRO \
JS_ASSERT(expr); \
if (!(expr)) { BAD_EXIT; } \
JS_END_MACRO
#define LOCAL_ASSERT_RV(expr, rv) \
LOCAL_ASSERT_CUSTOM(expr, return (rv))
static JSAtom *
GetArgOrVarAtom(JSPrinter *jp, uintN slot)
{
LOCAL_ASSERT_RV(jp->fun, NULL);
LOCAL_ASSERT_RV(slot < jp->fun->script()->bindings.countLocalNames(), NULL);
JSAtom *name = (*jp->localNames)[slot];
#if !JS_HAS_DESTRUCTURING
LOCAL_ASSERT_RV(name, NULL);
#endif
return name;
}
const char *
GetLocal(SprintStack *ss, jsint i)
{
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_RV(expr, "")
ptrdiff_t off = ss->offsets[i];
if (off >= 0)
return OFF2STR(&ss->sprinter, off);
/*
* We must be called from js_DecompileValueGenerator (via Decompile) when
* dereferencing a local that's undefined or null. Search script->objects
* for the block containing this local by its stack index, i.
*
* In case of destructuring's use of JSOP_GETLOCAL, however, there may be
* no such local. This could mean no blocks (no script objects at all, or
* none of the script's object literals are blocks), or the stack slot i is
* not in a block. In either case, return GetStr(ss, i).
*/
JSScript *script = ss->printer->script;
if (!JSScript::isValidOffset(script->objectsOffset))
return GetStr(ss, i);
for (jsatomid j = 0, n = script->objects()->length; j != n; j++) {
JSObject *obj = script->getObject(j);
if (obj->isBlock()) {
jsint depth = OBJ_BLOCK_DEPTH(cx, obj);
jsint count = OBJ_BLOCK_COUNT(cx, obj);
if (jsuint(i - depth) < jsuint(count)) {
jsint slot = i - depth;
for (Shape::Range r(obj->lastProperty()); !r.empty(); r.popFront()) {
const Shape &shape = r.front();
if (shape.shortid == slot) {
LOCAL_ASSERT(JSID_IS_ATOM(shape.propid));
JSAtom *atom = JSID_TO_ATOM(shape.propid);
const char *rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
return rval;
}
}
break;
}
}
}
return GetStr(ss, i);
#undef LOCAL_ASSERT
}
static JSBool
IsVarSlot(JSPrinter *jp, jsbytecode *pc, jsint *indexp)
{
uintN slot;
slot = GET_SLOTNO(pc);
if (slot < jp->script->nfixed) {
/* The slot refers to a variable with name stored in jp->localNames. */
*indexp = jp->fun->nargs + slot;
return JS_TRUE;
}
/* We have a local which index is relative to the stack base. */
slot -= jp->script->nfixed;
JS_ASSERT(slot < StackDepth(jp->script));
*indexp = slot;
return JS_FALSE;
}
#define LOAD_ATOM(PCOFF) \
GET_ATOM_FROM_BYTECODE(jp->script, pc, PCOFF, atom)
#if JS_HAS_DESTRUCTURING
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_RV(expr, NULL)
#define LOAD_OP_DATA(pc) (oplen = (cs = &js_CodeSpec[op=(JSOp)*pc])->length)
static jsbytecode *
DecompileDestructuring(SprintStack *ss, jsbytecode *pc, jsbytecode *endpc);
static jsbytecode *
DecompileDestructuringLHS(SprintStack *ss, jsbytecode *pc, jsbytecode *endpc,
JSBool *hole)
{
JSContext *cx;
JSPrinter *jp;
JSOp op;
const JSCodeSpec *cs;
uintN oplen;
jsint i;
const char *lval, *xval;
ptrdiff_t todo;
JSAtom *atom;
*hole = JS_FALSE;
cx = ss->sprinter.context;
jp = ss->printer;
LOAD_OP_DATA(pc);
switch (op) {
case JSOP_POP:
*hole = JS_TRUE;
todo = SprintPut(&ss->sprinter, ", ", 2);
break;
case JSOP_DUP:
pc = DecompileDestructuring(ss, pc, endpc);
if (!pc)
return NULL;
if (pc == endpc)
return pc;
LOAD_OP_DATA(pc);
lval = PopStr(ss, JSOP_NOP);
todo = SprintCString(&ss->sprinter, lval);
if (op == JSOP_POPN)
return pc;
LOCAL_ASSERT(*pc == JSOP_POP);
break;
case JSOP_SETARG:
case JSOP_SETLOCAL:
LOCAL_ASSERT(pc[oplen] == JSOP_POP || pc[oplen] == JSOP_POPN);
/* FALL THROUGH */
case JSOP_SETLOCALPOP:
atom = NULL;
lval = NULL;
if (op == JSOP_SETARG) {
atom = GetArgOrVarAtom(jp, GET_SLOTNO(pc));
LOCAL_ASSERT(atom);
} else if (IsVarSlot(jp, pc, &i)) {
atom = GetArgOrVarAtom(jp, i);
LOCAL_ASSERT(atom);
} else {
lval = GetLocal(ss, i);
}
{
JSAutoByteString bytes;
if (atom)
lval = js_AtomToPrintableString(cx, atom, &bytes);
LOCAL_ASSERT(lval);
todo = SprintCString(&ss->sprinter, lval);
}
if (op != JSOP_SETLOCALPOP) {
pc += oplen;
if (pc == endpc)
return pc;
LOAD_OP_DATA(pc);
if (op == JSOP_POPN)
return pc;
LOCAL_ASSERT(op == JSOP_POP);
}
break;
default:
/*
* We may need to auto-parenthesize the left-most value decompiled
* here, so add back PAREN_SLOP temporarily. Then decompile until the
* opcode that would reduce the stack depth to (ss->top-1), which we
* pass to Decompile encoded as -(ss->top-1) - 1 or just -ss->top for
* the nb parameter.
*/
todo = ss->sprinter.offset;
ss->sprinter.offset = todo + PAREN_SLOP;
pc = Decompile(ss, pc, -((intN)ss->top), JSOP_NOP);
if (!pc)
return NULL;
if (pc == endpc)
return pc;
LOAD_OP_DATA(pc);
LOCAL_ASSERT(op == JSOP_ENUMELEM || op == JSOP_ENUMCONSTELEM);
xval = PopStr(ss, JSOP_NOP);
lval = PopStr(ss, JSOP_GETPROP);
ss->sprinter.offset = todo;
if (*lval == '\0') {
/* lval is from JSOP_BINDNAME, so just print xval. */
todo = SprintCString(&ss->sprinter, xval);
} else if (*xval == '\0') {
/* xval is from JSOP_SETCALL or JSOP_BINDXMLNAME, print lval. */
todo = SprintCString(&ss->sprinter, lval);
} else {
todo = Sprint(&ss->sprinter,
(JOF_OPMODE(ss->opcodes[ss->top+1]) == JOF_XMLNAME)
? "%s.%s"
: "%s[%s]",
lval, xval);
}
break;
}
if (todo < 0)
return NULL;
LOCAL_ASSERT(pc < endpc);
pc += oplen;
return pc;
}
/*
* Starting with a SRC_DESTRUCT-annotated JSOP_DUP, decompile a destructuring
* left-hand side object or array initialiser, including nested destructuring
* initialisers. On successful return, the decompilation will be pushed on ss
* and the return value will point to the POP or GROUP bytecode following the
* destructuring expression.
*
* At any point, if pc is equal to endpc and would otherwise advance, we stop
* immediately and return endpc.
*/
static jsbytecode *
DecompileDestructuring(SprintStack *ss, jsbytecode *pc, jsbytecode *endpc)
{
ptrdiff_t head;
JSContext *cx;
JSPrinter *jp;
JSOp op, saveop;
const JSCodeSpec *cs;
uintN oplen;
jsint i, lasti;
jsdouble d;
const char *lval;
JSAtom *atom;
jssrcnote *sn;
JSBool hole;
LOCAL_ASSERT(*pc == JSOP_DUP);
pc += JSOP_DUP_LENGTH;
/*
* Set head so we can rewrite '[' to '{' as needed. Back up PAREN_SLOP
* chars so the destructuring decompilation accumulates contiguously in
* ss->sprinter starting with "[".
*/
head = SprintPut(&ss->sprinter, "[", 1);
if (head < 0 || !PushOff(ss, head, JSOP_NOP))
return NULL;
ss->sprinter.offset -= PAREN_SLOP;
LOCAL_ASSERT(head == ss->sprinter.offset - 1);
LOCAL_ASSERT(*OFF2STR(&ss->sprinter, head) == '[');
cx = ss->sprinter.context;
jp = ss->printer;
lasti = -1;
while (pc < endpc) {
#if JS_HAS_DESTRUCTURING_SHORTHAND
ptrdiff_t nameoff = -1;
#endif
LOAD_OP_DATA(pc);
saveop = op;
switch (op) {
case JSOP_POP:
pc += oplen;
goto out;
/* Handle the optimized number-pushing opcodes. */
case JSOP_ZERO: d = i = 0; goto do_getelem;
case JSOP_ONE: d = i = 1; goto do_getelem;
case JSOP_UINT16: d = i = GET_UINT16(pc); goto do_getelem;
case JSOP_UINT24: d = i = GET_UINT24(pc); goto do_getelem;
case JSOP_INT8: d = i = GET_INT8(pc); goto do_getelem;
case JSOP_INT32: d = i = GET_INT32(pc); goto do_getelem;
case JSOP_DOUBLE:
GET_DOUBLE_FROM_BYTECODE(jp->script, pc, 0, d);
LOCAL_ASSERT(JSDOUBLE_IS_FINITE(d) && !JSDOUBLE_IS_NEGZERO(d));
i = (jsint)d;
do_getelem:
sn = js_GetSrcNote(jp->script, pc);
pc += oplen;
if (pc == endpc)
return pc;
LOAD_OP_DATA(pc);
LOCAL_ASSERT(op == JSOP_GETELEM);
/* Distinguish object from array by opcode or source note. */
if (sn && SN_TYPE(sn) == SRC_INITPROP) {
*OFF2STR(&ss->sprinter, head) = '{';
if (Sprint(&ss->sprinter, "%g: ", d) < 0)
return NULL;
} else {
/* Sanity check for the gnarly control flow above. */
LOCAL_ASSERT(i == d);
/* Fill in any holes (holes at the end don't matter). */
while (++lasti < i) {
if (SprintPut(&ss->sprinter, ", ", 2) < 0)
return NULL;
}
}
break;
case JSOP_CALLPROP:
case JSOP_GETPROP:
case JSOP_LENGTH:
{
LOAD_ATOM(0);
*OFF2STR(&ss->sprinter, head) = '{';
#if JS_HAS_DESTRUCTURING_SHORTHAND
nameoff = ss->sprinter.offset;
#endif
if (!QuoteString(&ss->sprinter, atom,
js_IsIdentifier(atom) ? 0 : (jschar)'\'')) {
return NULL;
}
if (SprintPut(&ss->sprinter, ": ", 2) < 0)
return NULL;
break;
}
default:
LOCAL_ASSERT(0);
}
pc += oplen;
if (pc == endpc)
return pc;
/*
* Decompile the left-hand side expression whose bytecode starts at pc
* and continues for a bounded number of bytecodes or stack operations
* (and which in any event stops before endpc).
*/
pc = DecompileDestructuringLHS(ss, pc, endpc, &hole);
if (!pc)
return NULL;
#if JS_HAS_DESTRUCTURING_SHORTHAND
if (nameoff >= 0) {
ptrdiff_t offset, initlen;
offset = ss->sprinter.offset;
LOCAL_ASSERT(*OFF2STR(&ss->sprinter, offset) == '\0');
initlen = offset - nameoff;
LOCAL_ASSERT(initlen >= 4);
/* Early check to rule out odd "name: lval" length. */
if (((size_t)initlen & 1) == 0) {
size_t namelen;
const char *name;
/*
* Even "name: lval" string length: check for "x: x" and the
* like, and apply the shorthand if we can.
*/
namelen = (size_t)(initlen - 2) >> 1;
name = OFF2STR(&ss->sprinter, nameoff);
if (!strncmp(name + namelen, ": ", 2) &&
!strncmp(name, name + namelen + 2, namelen)) {
offset -= namelen + 2;
*OFF2STR(&ss->sprinter, offset) = '\0';
ss->sprinter.offset = offset;
}
}
}
#endif
if (pc == endpc || *pc != JSOP_DUP)
break;
/*
* We should stop if JSOP_DUP is either without notes or its note is
* not SRC_CONTINUE. The former happens when JSOP_DUP duplicates the
* last destructuring reference implementing an op= assignment like in
* '([t] = z).y += x'. In the latter case the note is SRC_DESTRUCT and
* means another destructuring initialiser abuts this one like in
* '[a] = [b] = c'.
*/
sn = js_GetSrcNote(jp->script, pc);
if (!sn)
break;
if (SN_TYPE(sn) != SRC_CONTINUE) {
LOCAL_ASSERT(SN_TYPE(sn) == SRC_DESTRUCT);
break;
}
if (!hole && SprintPut(&ss->sprinter, ", ", 2) < 0)
return NULL;
pc += JSOP_DUP_LENGTH;
}
out:
lval = OFF2STR(&ss->sprinter, head);
if (SprintPut(&ss->sprinter, (*lval == '[') ? "]" : "}", 1) < 0)
return NULL;
return pc;
}
static jsbytecode *
DecompileGroupAssignment(SprintStack *ss, jsbytecode *pc, jsbytecode *endpc,
jssrcnote *sn, ptrdiff_t *todop)
{
JSOp op;
const JSCodeSpec *cs;
uintN oplen, start, end, i;
ptrdiff_t todo;
JSBool hole;
const char *rval;
LOAD_OP_DATA(pc);
LOCAL_ASSERT(op == JSOP_PUSH || op == JSOP_GETLOCAL);
todo = Sprint(&ss->sprinter, "%s[", VarPrefix(sn));
if (todo < 0 || !PushOff(ss, todo, JSOP_NOP))
return NULL;
ss->sprinter.offset -= PAREN_SLOP;
for (;;) {
pc += oplen;
if (pc == endpc)
return pc;
pc = DecompileDestructuringLHS(ss, pc, endpc, &hole);
if (!pc)
return NULL;
if (pc == endpc)
return pc;
LOAD_OP_DATA(pc);
if (op != JSOP_PUSH && op != JSOP_GETLOCAL)
break;
if (!hole && SprintPut(&ss->sprinter, ", ", 2) < 0)
return NULL;
}
LOCAL_ASSERT(op == JSOP_POPN);
if (SprintPut(&ss->sprinter, "] = [", 5) < 0)
return NULL;
end = ss->top - 1;
start = end - GET_UINT16(pc);
for (i = start; i < end; i++) {
rval = GetStr(ss, i);
if (Sprint(&ss->sprinter,
(i == start) ? "%s" : ", %s",
(i == end - 1 && *rval == '\0') ? ", " : rval) < 0) {
return NULL;
}
}
if (SprintPut(&ss->sprinter, "]", 1) < 0)
return NULL;
ss->sprinter.offset = ss->offsets[i];
ss->top = start;
*todop = todo;
return pc;
}
#undef LOCAL_ASSERT
#undef LOAD_OP_DATA
#endif /* JS_HAS_DESTRUCTURING */
static JSBool
InitSprintStack(JSContext *cx, SprintStack *ss, JSPrinter *jp, uintN depth)
{
size_t offsetsz, opcodesz;
void *space;
INIT_SPRINTER(cx, &ss->sprinter, &cx->tempPool, PAREN_SLOP);
/* Allocate the parallel (to avoid padding) offset and opcode stacks. */
offsetsz = depth * sizeof(ptrdiff_t);
opcodesz = depth * sizeof(jsbytecode);
JS_ARENA_ALLOCATE(space, &cx->tempPool, offsetsz + opcodesz);
if (!space) {
js_ReportOutOfMemory(cx);
return JS_FALSE;
}
ss->offsets = (ptrdiff_t *) space;
ss->opcodes = (jsbytecode *) ((char *)space + offsetsz);
ss->top = ss->inArrayInit = 0;
ss->inGenExp = JS_FALSE;
ss->printer = jp;
return JS_TRUE;
}
/*
* If nb is non-negative, decompile nb bytecodes starting at pc. Otherwise
* the decompiler starts at pc and continues until it reaches an opcode for
* which decompiling would result in the stack depth equaling -(nb + 1).
*
* The nextop parameter is either JSOP_NOP or the "next" opcode in order of
* abstract interpretation (not necessarily physically next in a bytecode
* vector). So nextop is JSOP_POP for the last operand in a comma expression,
* or JSOP_AND for the right operand of &&.
*/
static jsbytecode *
Decompile(SprintStack *ss, jsbytecode *pc, intN nb, JSOp nextop)
{
JSContext *cx;
JSPrinter *jp, *jp2;
jsbytecode *startpc, *endpc, *pc2, *done;
ptrdiff_t tail, todo, len, oplen, cond, next;
JSOp op, lastop, saveop;
const JSCodeSpec *cs;
jssrcnote *sn, *sn2;
const char *lval, *rval, *xval, *fmt, *token;
uintN nuses;
jsint i, argc;
char **argv;
JSAtom *atom;
JSObject *obj;
JSFunction *fun = NULL; /* init to shut GCC up */
JSString *str;
JSBool ok;
#if JS_HAS_XML_SUPPORT
JSBool foreach, inXML, quoteAttr;
#else
#define inXML JS_FALSE
#endif
jsval val;
static const char exception_cookie[] = "/*EXCEPTION*/";
static const char retsub_pc_cookie[] = "/*RETSUB_PC*/";
static const char forelem_cookie[] = "/*FORELEM*/";
static const char with_cookie[] = "/*WITH*/";
static const char dot_format[] = "%s.%s";
static const char index_format[] = "%s[%s]";
static const char predot_format[] = "%s%s.%s";
static const char postdot_format[] = "%s.%s%s";
static const char preindex_format[] = "%s%s[%s]";
static const char postindex_format[] = "%s[%s]%s";
static const char ss_format[] = "%s%s";
static const char sss_format[] = "%s%s%s";
/* Argument and variables decompilation uses the following to share code. */
JS_STATIC_ASSERT(ARGNO_LEN == SLOTNO_LEN);
/*
* Local macros
*/
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_RV(expr, NULL)
#define DECOMPILE_CODE_CLEANUP(pc,nb,cleanup) if (!Decompile(ss, pc, nb, JSOP_NOP)) cleanup
#define DECOMPILE_CODE(pc,nb) DECOMPILE_CODE_CLEANUP(pc,nb,return NULL)
#define NEXT_OP(pc) (((pc) + (len) == endpc) ? nextop : pc[len])
#define TOP_STR() GetStr(ss, ss->top - 1)
#define POP_STR() PopStr(ss, op)
#define POP_STR_PREC(prec) PopStrPrec(ss, prec)
/*
* Pop a condition expression for if/while. JSOP_IFEQ's precedence forces
* extra parens around assignment, which avoids a strict-mode warning.
*/
#define POP_COND_STR() \
PopStr(ss, (js_CodeSpec[ss->opcodes[ss->top - 1]].format & JOF_SET) \
? JSOP_IFEQ \
: JSOP_NOP)
#define ATOM_IS_IDENTIFIER(atom) js_IsIdentifier(atom)
/*
* Given an atom already fetched from jp->script's atom map, quote/escape its
* string appropriately into rval, and select fmt from the quoted and unquoted
* alternatives.
*/
#define GET_QUOTE_AND_FMT(qfmt, ufmt, rval) \
JS_BEGIN_MACRO \
jschar quote_; \
if (!ATOM_IS_IDENTIFIER(atom)) { \
quote_ = '\''; \
fmt = qfmt; \
} else { \
quote_ = 0; \
fmt = ufmt; \
} \
rval = QuoteString(&ss->sprinter, atom, quote_); \
if (!rval) \
return NULL; \
JS_END_MACRO
#define LOAD_OBJECT(PCOFF) \
GET_OBJECT_FROM_BYTECODE(jp->script, pc, PCOFF, obj)
#define LOAD_FUNCTION(PCOFF) \
GET_FUNCTION_FROM_BYTECODE(jp->script, pc, PCOFF, fun)
#define LOAD_REGEXP(PCOFF) \
GET_REGEXP_FROM_BYTECODE(jp->script, pc, PCOFF, obj)
#define GET_SOURCE_NOTE_ATOM(sn, atom) \
JS_BEGIN_MACRO \
jsatomid atomIndex_ = (jsatomid) js_GetSrcNoteOffset((sn), 0); \
\
LOCAL_ASSERT(atomIndex_ < jp->script->natoms); \
(atom) = jp->script->atoms[atomIndex_]; \
JS_END_MACRO
/*
* Get atom from jp->script's atom map, quote/escape its string appropriately
* into rval, and select fmt from the quoted and unquoted alternatives.
*/
#define GET_ATOM_QUOTE_AND_FMT(qfmt, ufmt, rval) \
JS_BEGIN_MACRO \
LOAD_ATOM(0); \
GET_QUOTE_AND_FMT(qfmt, ufmt, rval); \
JS_END_MACRO
/*
* Per spec, new x(y).z means (new x(y))).z. For example new (x(y).z) must
* decompile with the constructor parenthesized, but new x.z should not. The
* normal rules give x(y).z and x.z identical precedence: both are produced by
* JSOP_GETPROP.
*
* Therefore, we need to know in case JSOP_NEW whether the constructor
* expression contains any unparenthesized function calls. So when building a
* MemberExpression or CallExpression, we set ss->opcodes[n] to JSOP_CALL if
* this is true. x(y).z gets JSOP_CALL, not JSOP_GETPROP.
*/
#define PROPAGATE_CALLNESS() \
JS_BEGIN_MACRO \
if (ss->opcodes[ss->top - 1] == JSOP_CALL || \
ss->opcodes[ss->top - 1] == JSOP_EVAL || \
ss->opcodes[ss->top - 1] == JSOP_FUNCALL || \
ss->opcodes[ss->top - 1] == JSOP_FUNAPPLY) { \
saveop = JSOP_CALL; \
} \
JS_END_MACRO
cx = ss->sprinter.context;
JS_CHECK_RECURSION(cx, return NULL);
jp = ss->printer;
startpc = pc;
endpc = (nb < 0) ? jp->script->code + jp->script->length : pc + nb;
tail = -1;
todo = -2; /* NB: different from Sprint() error return. */
saveop = JSOP_NOP;
sn = NULL;
rval = NULL;
#if JS_HAS_XML_SUPPORT
foreach = inXML = quoteAttr = JS_FALSE;
#endif
while (nb < 0 || pc < endpc) {
/*
* Move saveop to lastop so prefixed bytecodes can take special action
* while sharing maximal code. Set op and saveop to the new bytecode,
* use op in POP_STR to trigger automatic parenthesization, but push
* saveop at the bottom of the loop if this op pushes. Thus op may be
* set to nop or otherwise mutated to suppress auto-parens.
*/
lastop = saveop;
op = (JSOp) *pc;
cs = &js_CodeSpec[op];
if (cs->format & JOF_INDEXBASE) {
/*
* The decompiler uses js_GetIndexFromBytecode to get atoms and
* objects and ignores these suffix/prefix bytecodes, thus
* simplifying code that must process JSOP_GETTER/JSOP_SETTER
* prefixes.
*/
pc += cs->length;
if (pc >= endpc)
break;
op = (JSOp) *pc;
cs = &js_CodeSpec[op];
}
saveop = op;
len = oplen = cs->length;
nuses = js_GetStackUses(cs, op, pc);
/*
* Here it is possible that nuses > ss->top when the op has a hidden
* source note. But when nb < 0 we assume that the caller knows that
* Decompile would never meet such opcodes.
*/
if (nb < 0) {
LOCAL_ASSERT(ss->top >= nuses);
uintN ndefs = js_GetStackDefs(cx, cs, op, jp->script, pc);
if ((uintN) -(nb + 1) == ss->top - nuses + ndefs)
return pc;
}
/*
* Save source literal associated with JS now before the following
* rewrite changes op. See bug 380197.
*/
token = CodeToken[op];
if (pc + oplen == jp->dvgfence) {
/*
* Rewrite non-get ops to their "get" format if the error is in
* the bytecode at pc, so we don't decompile more than the error
* expression.
*/
StackFrame *fp = js_GetScriptedCaller(cx, NULL);
uint32 format = cs->format;
if (((fp && pc == fp->pcQuadratic(cx)) ||
(pc == startpc && nuses != 0)) &&
format & (JOF_SET|JOF_DEL|JOF_INCDEC|JOF_FOR|JOF_VARPROP)) {
uint32 mode = JOF_MODE(format);
if (mode == JOF_NAME) {
/*
* JOF_NAME does not imply JOF_ATOM, so we must check for
* the QARG and QVAR format types, and translate those to
* JSOP_GETARG or JSOP_GETLOCAL appropriately, instead of
* to JSOP_NAME.
*/
uint32 type = JOF_TYPE(format);
op = (type == JOF_QARG)
? JSOP_GETARG
: (type == JOF_LOCAL)
? JSOP_GETLOCAL
: JSOP_NAME;
JS_ASSERT(js_CodeSpec[op].nuses >= 0);
i = nuses - js_CodeSpec[op].nuses;
while (--i >= 0)
PopOff(ss, JSOP_NOP);
} else {
/*
* We must replace the faulting pc's bytecode with a
* corresponding JSOP_GET* code. For JSOP_SET{PROP,ELEM},
* we must use the "2nd" form of JSOP_GET{PROP,ELEM}, to
* throw away the assignment op's right-hand operand and
* decompile it as if it were a GET of its left-hand
* operand.
*/
if (mode == JOF_PROP) {
op = (JSOp) ((format & JOF_SET)
? JSOP_GETPROP2
: JSOP_GETPROP);
} else if (mode == JOF_ELEM) {
op = (JSOp) ((format & JOF_SET)
? JSOP_GETELEM2
: JSOP_GETELEM);
} else {
/*
* Unknown mode (including mode 0) means that op is
* uncategorized for our purposes, so we must write
* per-op special case code here.
*/
switch (op) {
case JSOP_ENUMELEM:
case JSOP_ENUMCONSTELEM:
op = JSOP_GETELEM;
break;
case JSOP_SETXMLNAME:
op = JSOp(JSOP_GETELEM2);
break;
default:
LOCAL_ASSERT(0);
}
}
}
}
saveop = op;
if (op >= JSOP_LIMIT) {
if (op == JSOP_GETPROP2)
saveop = JSOP_GETPROP;
else if (op == JSOP_GETELEM2)
saveop = JSOP_GETELEM;
}
jp->dvgfence = NULL;
}
if (token) {
switch (nuses) {
case 2:
sn = js_GetSrcNote(jp->script, pc);
if (sn && SN_TYPE(sn) == SRC_ASSIGNOP) {
/*
* Avoid over-parenthesizing y in x op= y based on its
* expansion: x = x op y (replace y by z = w to see the
* problem).
*/
op = (JSOp) pc[oplen];
rval = POP_STR();
lval = POP_STR();
/* Print only the right operand of the assignment-op. */
todo = SprintCString(&ss->sprinter, rval);
op = saveop;
} else if (!inXML) {
rval = POP_STR_PREC(cs->prec + !!(cs->format & JOF_LEFTASSOC));
lval = POP_STR_PREC(cs->prec + !(cs->format & JOF_LEFTASSOC));
todo = Sprint(&ss->sprinter, "%s %s %s",
lval, token, rval);
} else {
/* In XML, just concatenate the two operands. */
LOCAL_ASSERT(op == JSOP_ADD);
rval = POP_STR();
lval = POP_STR();
todo = Sprint(&ss->sprinter, ss_format, lval, rval);
}
break;
case 1:
rval = POP_STR();
todo = Sprint(&ss->sprinter, ss_format, token, rval);
break;
case 0:
todo = SprintCString(&ss->sprinter, token);
break;
default:
todo = -2;
break;
}
} else {
switch (op) {
case JSOP_NOP:
/*
* Check for a do-while loop, a for-loop with an empty
* initializer part, a labeled statement, a function
* definition, or try/finally.
*/
sn = js_GetSrcNote(jp->script, pc);
todo = -2;
switch (sn ? SN_TYPE(sn) : SRC_NULL) {
case SRC_WHILE:
/* First instuction (NOP) contains offset to condition */
++pc;
/* Second instruction (TRACE) contains offset to JSOP_IFNE */
sn = js_GetSrcNote(jp->script, pc);
tail = js_GetSrcNoteOffset(sn, 0);
LOCAL_ASSERT(pc[tail] == JSOP_IFNE ||
pc[tail] == JSOP_IFNEX);
js_printf(jp, "\tdo {\n");
jp->indent += 4;
DECOMPILE_CODE(pc, tail);
jp->indent -= 4;
js_printf(jp, "\t} while (%s);\n", POP_COND_STR());
pc += tail;
len = js_CodeSpec[*pc].length;
todo = -2;
break;
case SRC_FOR:
rval = "";
do_forloop:
JS_ASSERT(SN_TYPE(sn) == SRC_FOR);
/* Skip the JSOP_NOP or JSOP_POP bytecode. */
pc += JSOP_NOP_LENGTH;
/* Get the cond, next, and loop-closing tail offsets. */
cond = js_GetSrcNoteOffset(sn, 0);
next = js_GetSrcNoteOffset(sn, 1);
tail = js_GetSrcNoteOffset(sn, 2);
/*
* If this loop has a condition, then pc points at a goto
* targeting the condition.
*/
pc2 = pc;
if (cond != tail) {
LOCAL_ASSERT(*pc == JSOP_GOTO || *pc == JSOP_GOTOX);
pc2 += (*pc == JSOP_GOTO) ? JSOP_GOTO_LENGTH : JSOP_GOTOX_LENGTH;
}
LOCAL_ASSERT(tail + GetJumpOffset(pc+tail, pc+tail) == pc2 - pc);
/* Print the keyword and the possibly empty init-part. */
js_printf(jp, "\tfor (%s;", rval);
if (cond != tail) {
/* Decompile the loop condition. */
DECOMPILE_CODE(pc + cond, tail - cond);
js_printf(jp, " %s", POP_STR());
}
/* Need a semicolon whether or not there was a cond. */
js_puts(jp, ";");
if (next != cond) {
/*
* Decompile the loop updater. It may end in a JSOP_POP
* that we skip; or in a JSOP_POPN that we do not skip,
* followed by a JSOP_NOP (skipped as if it's a POP).
* We cope with the difference between these two cases
* by checking for stack imbalance and popping if there
* is an rval.
*/
uintN saveTop = ss->top;
DECOMPILE_CODE(pc + next, cond - next - JSOP_POP_LENGTH);
LOCAL_ASSERT(ss->top - saveTop <= 1U);
rval = (ss->top == saveTop)
? ss->sprinter.base + ss->sprinter.offset
: POP_STR();
js_printf(jp, " %s", rval);
}
/* Do the loop body. */
js_printf(jp, ") {\n");
jp->indent += 4;
next -= pc2 - pc;
DECOMPILE_CODE(pc2, next);
jp->indent -= 4;
js_printf(jp, "\t}\n");
/* Set len so pc skips over the entire loop. */
len = tail + js_CodeSpec[pc[tail]].length;
break;
case SRC_LABEL:
GET_SOURCE_NOTE_ATOM(sn, atom);
jp->indent -= 4;
rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
js_printf(jp, "\t%s:\n", rval);
jp->indent += 4;
break;
case SRC_LABELBRACE:
GET_SOURCE_NOTE_ATOM(sn, atom);
rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
js_printf(jp, "\t%s: {\n", rval);
jp->indent += 4;
break;
case SRC_ENDBRACE:
jp->indent -= 4;
js_printf(jp, "\t}\n");
break;
case SRC_FUNCDEF:
fun = jp->script->getFunction(js_GetSrcNoteOffset(sn, 0));
do_function:
js_puts(jp, "\n");
jp2 = js_NewPrinter(cx, "nested_function", fun,
jp->indent, jp->pretty, jp->grouped,
jp->strict);
if (!jp2)
return NULL;
ok = js_DecompileFunction(jp2);
if (ok && jp2->sprinter.base)
js_puts(jp, jp2->sprinter.base);
js_DestroyPrinter(jp2);
if (!ok)
return NULL;
js_puts(jp, "\n\n");
break;
case SRC_BRACE:
js_printf(jp, "\t{\n");
jp->indent += 4;
len = js_GetSrcNoteOffset(sn, 0);
DECOMPILE_CODE(pc + oplen, len - oplen);
jp->indent -= 4;
js_printf(jp, "\t}\n");
break;
default:;
}
break;
case JSOP_PUSH:
#if JS_HAS_DESTRUCTURING
sn = js_GetSrcNote(jp->script, pc);
if (sn && SN_TYPE(sn) == SRC_GROUPASSIGN) {
pc = DecompileGroupAssignment(ss, pc, endpc, sn, &todo);
if (!pc)
return NULL;
LOCAL_ASSERT(*pc == JSOP_POPN);
len = oplen = JSOP_POPN_LENGTH;
goto end_groupassignment;
}
#endif
/* FALL THROUGH */
case JSOP_BINDNAME:
case JSOP_BINDGNAME:
todo = Sprint(&ss->sprinter, "");
break;
case JSOP_TRY:
js_printf(jp, "\ttry {\n");
jp->indent += 4;
todo = -2;
break;
case JSOP_FINALLY:
jp->indent -= 4;
js_printf(jp, "\t} finally {\n");
jp->indent += 4;
/*
* We push push the pair of exception/restsub cookies to
* simulate the effects [gosub] or control transfer during
* exception capturing on the stack.
*/
todo = Sprint(&ss->sprinter, exception_cookie);
if (todo < 0 || !PushOff(ss, todo, op))
return NULL;
todo = Sprint(&ss->sprinter, retsub_pc_cookie);
break;
case JSOP_RETSUB:
rval = POP_STR();
LOCAL_ASSERT(strcmp(rval, retsub_pc_cookie) == 0);
lval = POP_STR();
LOCAL_ASSERT(strcmp(lval, exception_cookie) == 0);
todo = -2;
break;
case JSOP_GOSUB:
case JSOP_GOSUBX:
/*
* JSOP_GOSUB and GOSUBX have no effect on the decompiler's
* string stack because the next op in bytecode order finds
* the stack balanced by a JSOP_RETSUB executed elsewhere.
*/
todo = -2;
break;
case JSOP_POPN:
{
uintN newtop, oldtop;
/*
* The compiler models operand stack depth and fixes the stack
* pointer on entry to a catch clause based on its depth model.
* The decompiler must match the code generator's model, which
* is why JSOP_FINALLY pushes a cookie that JSOP_RETSUB pops.
*/
oldtop = ss->top;
newtop = oldtop - GET_UINT16(pc);
LOCAL_ASSERT(newtop <= oldtop);
todo = -2;
sn = js_GetSrcNote(jp->script, pc);
if (sn && SN_TYPE(sn) == SRC_HIDDEN)
break;
#if JS_HAS_DESTRUCTURING
if (sn && SN_TYPE(sn) == SRC_GROUPASSIGN) {
todo = Sprint(&ss->sprinter, "%s[] = [",
VarPrefix(sn));
if (todo < 0)
return NULL;
for (uintN i = newtop; i < oldtop; i++) {
rval = OFF2STR(&ss->sprinter, ss->offsets[i]);
if (Sprint(&ss->sprinter, ss_format,
(i == newtop) ? "" : ", ",
(i == oldtop - 1 && *rval == '\0')
? ", " : rval) < 0) {
return NULL;
}
}
if (SprintPut(&ss->sprinter, "]", 1) < 0)
return NULL;
/*
* If this is an empty group assignment, we have no stack
* budget into which we can push our result string. Adjust
* ss->sprinter.offset so that our consumer can find the
* empty group assignment decompilation.
*/
if (newtop == oldtop) {
ss->sprinter.offset = todo;
} else {
/*
* Kill newtop before the end_groupassignment: label by
* retracting/popping early. Control will either jump
* to do_forloop: or do_letheadbody: or else break from
* our case JSOP_POPN: after the switch (*pc2) below.
*/
LOCAL_ASSERT(newtop < oldtop);
ss->sprinter.offset = GetOff(ss, newtop);
ss->top = newtop;
}
end_groupassignment:
LOCAL_ASSERT(*pc == JSOP_POPN);
/*
* Thread directly to the next opcode if we can, to handle
* the special cases of a group assignment in the first or
* last part of a for(;;) loop head, or in a let block or
* expression head.
*
* NB: todo at this point indexes space in ss->sprinter
* that is liable to be overwritten. The code below knows
* exactly how long rval lives, or else copies it down via
* SprintCString.
*/
rval = OFF2STR(&ss->sprinter, todo);
todo = -2;
pc2 = pc + oplen;
/* Skip a block chain annotation if one appears here. */
if (*pc2 == JSOP_NOP) {
if (pc2[JSOP_NOP_LENGTH] == JSOP_NULLBLOCKCHAIN)
pc2 += JSOP_NOP_LENGTH + JSOP_NULLBLOCKCHAIN_LENGTH;
else if (pc2[JSOP_NOP_LENGTH] == JSOP_BLOCKCHAIN)
pc2 += JSOP_NOP_LENGTH + JSOP_BLOCKCHAIN_LENGTH;
}
if (*pc2 == JSOP_NOP) {
sn = js_GetSrcNote(jp->script, pc2);
if (sn) {
if (SN_TYPE(sn) == SRC_FOR) {
op = JSOP_NOP;
pc = pc2;
goto do_forloop;
}
if (SN_TYPE(sn) == SRC_DECL) {
if (ss->top == StackDepth(jp->script)) {
/*
* This must be an empty destructuring
* in the head of a let whose body block
* is also empty.
*/
pc = pc2 + JSOP_NOP_LENGTH;
len = js_GetSrcNoteOffset(sn, 0);
LOCAL_ASSERT(pc[len] == JSOP_LEAVEBLOCK);
js_printf(jp, "\tlet (%s) {\n", rval);
js_printf(jp, "\t}\n");
break;
}
todo = SprintCString(&ss->sprinter, rval);
if (todo < 0 || !PushOff(ss, todo, JSOP_NOP))
return NULL;
op = JSOP_POP;
pc = pc2 + JSOP_NOP_LENGTH;
goto do_letheadbody;
}
} else {
/*
* An unnannotated NOP following a POPN must be the
* third part of for(;;) loop head. If the POPN's
* immediate operand is 0, then we may have no slot
* on the sprint-stack in which to push our result
* string. In this case the result can be recovered
* at ss->sprinter.base + ss->sprinter.offset.
*/
if (GET_UINT16(pc) == 0)
break;
todo = SprintCString(&ss->sprinter, rval);
saveop = JSOP_NOP;
}
}
/*
* If control flow reaches this point with todo still -2,
* just print rval as an expression statement.
*/
if (todo == -2)
js_printf(jp, "\t%s;\n", rval);
break;
}
#endif
if (newtop < oldtop) {
ss->sprinter.offset = GetOff(ss, newtop);
ss->top = newtop;
}
break;
}
case JSOP_EXCEPTION:
/* The catch decompiler handles this op itself. */
LOCAL_ASSERT(JS_FALSE);
break;
case JSOP_POP:
/*
* By default, do not automatically parenthesize when popping
* a stacked expression decompilation. We auto-parenthesize
* only when JSOP_POP is annotated with SRC_PCDELTA, meaning
* comma operator.
*/
op = JSOP_POPV;
/* FALL THROUGH */
case JSOP_POPV:
sn = js_GetSrcNote(jp->script, pc);
switch (sn ? SN_TYPE(sn) : SRC_NULL) {
case SRC_FOR:
/* Force parens around 'in' expression at 'for' front. */
if (ss->opcodes[ss->top-1] == JSOP_IN)
op = JSOP_LSH;
rval = POP_STR();
todo = -2;
goto do_forloop;
case SRC_PCDELTA:
/* Comma operator: use JSOP_POP for correct precedence. */
op = JSOP_POP;
/* Pop and save to avoid blowing stack depth budget. */
lval = JS_strdup(cx, POP_STR());
if (!lval)
return NULL;
/*
* The offset tells distance to the end of the right-hand
* operand of the comma operator.
*/
done = pc + len;
pc += js_GetSrcNoteOffset(sn, 0);
len = 0;
if (!Decompile(ss, done, pc - done, JSOP_POP)) {
cx->free_((char *)lval);
return NULL;
}
/* Pop Decompile result and print comma expression. */
rval = POP_STR();
todo = Sprint(&ss->sprinter, "%s, %s", lval, rval);
cx->free_((char *)lval);
break;
case SRC_HIDDEN:
/* Hide this pop, it's from a goto in a with or for/in. */
todo = -2;
break;
case SRC_DECL:
/* This pop is at the end of the let block/expr head. */
pc += JSOP_POP_LENGTH;
#if JS_HAS_DESTRUCTURING
do_letheadbody:
#endif
len = js_GetSrcNoteOffset(sn, 0);
if (pc[len] == JSOP_LEAVEBLOCK) {
js_printf(jp, "\tlet (%s) {\n", POP_STR());
jp->indent += 4;
DECOMPILE_CODE(pc, len);
jp->indent -= 4;
js_printf(jp, "\t}\n");
todo = -2;
} else {
LOCAL_ASSERT(pc[len] == JSOP_LEAVEBLOCKEXPR);
lval = JS_strdup(cx, PopStr(ss, JSOP_NOP));
if (!lval)
return NULL;
/* Set saveop to reflect what we will push. */
saveop = JSOP_LEAVEBLOCKEXPR;
if (!Decompile(ss, pc, len, saveop)) {
cx->free_((char *)lval);
return NULL;
}
rval = PopStr(ss, JSOP_SETNAME);
todo = Sprint(&ss->sprinter,
(*rval == '{')
? "let (%s) (%s)"
: "let (%s) %s",
lval, rval);
cx->free_((char *)lval);
}
break;
default:
/* Turn off parens around a yield statement. */
if (ss->opcodes[ss->top-1] == JSOP_YIELD)
op = JSOP_NOP;
rval = POP_STR();
/*
* Don't emit decompiler-pushed strings that are not
* handled by other opcodes. They are pushed onto the
* stack to help model the interpreter stack and should
* not appear in the decompiler's output.
*/
if (*rval != '\0' && (rval[0] != '/' || rval[1] != '*')) {
js_printf(jp,
(*rval == '{' ||
(strncmp(rval, js_function_str, 8) == 0 &&
rval[8] == ' '))
? "\t(%s);\n"
: "\t%s;\n",
rval);
} else {
LOCAL_ASSERT(*rval == '\0' ||
strcmp(rval, exception_cookie) == 0);
}
todo = -2;
break;
}
sn = NULL;
break;
case JSOP_PICK:
{
uintN i = pc[1];
LOCAL_ASSERT(ss->top > i + 1);
uintN bottom = ss->top - (i + 1);
ptrdiff_t pickedOffset = ss->offsets[bottom];
memmove(ss->offsets + bottom, ss->offsets + bottom + 1,
i * sizeof(ss->offsets[0]));
ss->offsets[ss->top - 1] = pickedOffset;
jsbytecode pickedOpcode = ss->opcodes[bottom];
memmove(ss->opcodes + bottom, ss->opcodes + bottom + 1,
i * sizeof(ss->opcodes[0]));
ss->opcodes[ss->top - 1] = pickedOpcode;
todo = -2;
break;
}
case JSOP_ENTERWITH:
LOCAL_ASSERT(!js_GetSrcNote(jp->script, pc));
rval = POP_STR();
js_printf(jp, "\twith (%s) {\n", rval);
jp->indent += 4;
todo = Sprint(&ss->sprinter, with_cookie);
break;
case JSOP_LEAVEWITH:
sn = js_GetSrcNote(jp->script, pc);
todo = -2;
if (sn && SN_TYPE(sn) == SRC_HIDDEN)
break;
rval = POP_STR();
LOCAL_ASSERT(strcmp(rval, with_cookie) == 0);
jp->indent -= 4;
js_printf(jp, "\t}\n");
break;
case JSOP_ENTERBLOCK:
{
JSAtom **atomv, *smallv[5];
LOAD_OBJECT(0);
argc = OBJ_BLOCK_COUNT(cx, obj);
if ((size_t)argc <= JS_ARRAY_LENGTH(smallv)) {
atomv = smallv;
} else {
atomv = (JSAtom **) cx->malloc_(argc * sizeof(JSAtom *));
if (!atomv)
return NULL;
}
MUST_FLOW_THROUGH("enterblock_out");
#define LOCAL_ASSERT_OUT(expr) LOCAL_ASSERT_CUSTOM(expr, ok = JS_FALSE; \
goto enterblock_out)
for (Shape::Range r = obj->lastProperty()->all(); !r.empty(); r.popFront()) {
const Shape &shape = r.front();
if (!shape.hasShortID())
continue;
LOCAL_ASSERT_OUT(shape.shortid < argc);
atomv[shape.shortid] = JSID_TO_ATOM(shape.propid);
}
ok = JS_TRUE;
for (i = 0; i < argc; i++) {
atom = atomv[i];
rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval ||
!PushOff(ss, STR2OFF(&ss->sprinter, rval), op)) {
ok = JS_FALSE;
goto enterblock_out;
}
}
sn = js_GetSrcNote(jp->script, pc);
switch (sn ? SN_TYPE(sn) : SRC_NULL) {
#if JS_HAS_BLOCK_SCOPE
case SRC_BRACE:
js_printf(jp, "\t{\n");
jp->indent += 4;
len = js_GetSrcNoteOffset(sn, 0);
ok = Decompile(ss, pc + oplen, len - oplen, JSOP_NOP)
!= NULL;
if (!ok)
goto enterblock_out;
jp->indent -= 4;
js_printf(jp, "\t}\n");
break;
#endif
case SRC_CATCH:
jp->indent -= 4;
js_printf(jp, "\t} catch (");
pc2 = pc;
pc += oplen;
LOCAL_ASSERT_OUT(*pc == JSOP_EXCEPTION);
pc += JSOP_EXCEPTION_LENGTH;
todo = Sprint(&ss->sprinter, exception_cookie);
if (todo < 0 || !PushOff(ss, todo, JSOP_EXCEPTION)) {
ok = JS_FALSE;
goto enterblock_out;
}
if (*pc == JSOP_DUP) {
sn2 = js_GetSrcNote(jp->script, pc);
if (!sn2 || SN_TYPE(sn2) != SRC_DESTRUCT) {
/*
* This is a dup to save the exception for later.
* It is emitted only when the catch head contains
* an exception guard.
*/
LOCAL_ASSERT_OUT(js_GetSrcNoteOffset(sn, 0) != 0);
pc += JSOP_DUP_LENGTH;
todo = Sprint(&ss->sprinter, exception_cookie);
if (todo < 0 ||
!PushOff(ss, todo, JSOP_EXCEPTION)) {
ok = JS_FALSE;
goto enterblock_out;
}
}
}
#if JS_HAS_DESTRUCTURING
if (*pc == JSOP_DUP) {
pc = DecompileDestructuring(ss, pc, endpc);
if (!pc) {
ok = JS_FALSE;
goto enterblock_out;
}
LOCAL_ASSERT_OUT(*pc == JSOP_POP);
pc += JSOP_POP_LENGTH;
lval = PopStr(ss, JSOP_NOP);
js_puts(jp, lval);
} else {
#endif
LOCAL_ASSERT_OUT(*pc == JSOP_SETLOCALPOP);
i = GET_SLOTNO(pc) - jp->script->nfixed;
pc += JSOP_SETLOCALPOP_LENGTH;
atom = atomv[i - OBJ_BLOCK_DEPTH(cx, obj)];
str = atom;
if (!QuoteString(&jp->sprinter, str, 0)) {
ok = JS_FALSE;
goto enterblock_out;
}
#if JS_HAS_DESTRUCTURING
}
#endif
/*
* Pop the exception_cookie (or its dup in the case of a
* guarded catch head) off the stack now.
*/
rval = PopStr(ss, JSOP_NOP);
LOCAL_ASSERT_OUT(strcmp(rval, exception_cookie) == 0);
len = js_GetSrcNoteOffset(sn, 0);
if (len) {
len -= pc - pc2;
LOCAL_ASSERT_OUT(len > 0);
js_printf(jp, " if ");
ok = Decompile(ss, pc, len, JSOP_NOP) != NULL;
if (!ok)
goto enterblock_out;
js_printf(jp, "%s", POP_STR());
pc += len;
LOCAL_ASSERT_OUT(*pc == JSOP_IFEQ || *pc == JSOP_IFEQX);
pc += js_CodeSpec[*pc].length;
}
js_printf(jp, ") {\n");
jp->indent += 4;
len = 0;
break;
default:
break;
}
todo = -2;
#undef LOCAL_ASSERT_OUT
enterblock_out:
if (atomv != smallv)
cx->free_(atomv);
if (!ok)
return NULL;
}
break;
case JSOP_LEAVEBLOCK:
case JSOP_LEAVEBLOCKEXPR:
{
uintN top, depth;
sn = js_GetSrcNote(jp->script, pc);
todo = -2;
if (op == JSOP_LEAVEBLOCKEXPR) {
LOCAL_ASSERT(SN_TYPE(sn) == SRC_PCBASE);
rval = POP_STR();
} else if (sn) {
LOCAL_ASSERT(op == JSOP_LEAVEBLOCK);
if (SN_TYPE(sn) == SRC_HIDDEN)
break;
/*
* This JSOP_LEAVEBLOCK must be for a catch block. If sn's
* offset does not equal the model stack depth, there must
* be a copy of the exception value on the stack due to a
* catch guard (see above, the JSOP_ENTERBLOCK + SRC_CATCH
* case code).
*/
LOCAL_ASSERT(SN_TYPE(sn) == SRC_CATCH);
if ((uintN)js_GetSrcNoteOffset(sn, 0) != ss->top) {
LOCAL_ASSERT((uintN)js_GetSrcNoteOffset(sn, 0)
== ss->top - 1);
rval = POP_STR();
LOCAL_ASSERT(strcmp(rval, exception_cookie) == 0);
}
}
top = ss->top;
depth = GET_UINT16(pc);
LOCAL_ASSERT(top >= depth);
top -= depth;
ss->top = top;
ss->sprinter.offset = GetOff(ss, top);
if (op == JSOP_LEAVEBLOCKEXPR)
todo = SprintCString(&ss->sprinter, rval);
break;
}
case JSOP_GETFCSLOT:
case JSOP_CALLFCSLOT:
{
if (!jp->fun)
jp->fun = jp->script->getCallerFunction();
if (!jp->localNames) {
JS_ASSERT(fun == jp->fun);
jp->localNames = cx->new_<Vector<JSAtom *> >(cx);
if (!jp->localNames ||
!jp->fun->script()->bindings.getLocalNameArray(cx, jp->localNames))
{
return NULL;
}
}
uintN index = GET_UINT16(pc);
if (index < jp->fun->script()->bindings.countUpvars()) {
index += jp->fun->script()->bindings.countArgsAndVars();
} else {
JSUpvarArray *uva;
#ifdef DEBUG
/*
* We must be in an eval called from jp->fun, where
* jp->script is the eval-compiled script.
*
* However, it's possible that a js_Invoke already
* pushed a frame trying to call Construct on an
* object that's not a constructor, causing us to be
* called with an intervening frame on the stack.
*/
StackFrame *fp = js_GetTopStackFrame(cx, FRAME_EXPAND_NONE);
if (fp) {
while (!fp->isEvalFrame())
fp = fp->prev();
JS_ASSERT(fp->script() == jp->script);
JS_ASSERT(fp->prev()->fun() == jp->fun);
JS_ASSERT(jp->fun->isInterpreted());
JS_ASSERT(jp->script != jp->fun->script());
JS_ASSERT(JSScript::isValidOffset(jp->script->upvarsOffset));
}
#endif
uva = jp->script->upvars();
index = uva->vector[index].slot();
}
atom = GetArgOrVarAtom(jp, index);
goto do_name;
}
case JSOP_CALLLOCAL:
case JSOP_GETLOCAL:
if (IsVarSlot(jp, pc, &i)) {
atom = GetArgOrVarAtom(jp, i);
LOCAL_ASSERT(atom);
goto do_name;
}
LOCAL_ASSERT((uintN)i < ss->top);
sn = js_GetSrcNote(jp->script, pc);
#if JS_HAS_DESTRUCTURING
if (sn && SN_TYPE(sn) == SRC_GROUPASSIGN) {
/*
* Distinguish a js_DecompileValueGenerator call that
* targets op alone, from decompilation of a full group
* assignment sequence, triggered by SRC_GROUPASSIGN
* annotating the first JSOP_GETLOCAL in the sequence.
*/
if (endpc - pc > JSOP_GETLOCAL_LENGTH || pc > startpc) {
pc = DecompileGroupAssignment(ss, pc, endpc, sn, &todo);
if (!pc)
return NULL;
LOCAL_ASSERT(*pc == JSOP_POPN);
len = oplen = JSOP_POPN_LENGTH;
goto end_groupassignment;
}
/* Null sn to prevent bogus VarPrefix'ing below. */
sn = NULL;
}
#endif
rval = GetLocal(ss, i);
todo = Sprint(&ss->sprinter, ss_format, VarPrefix(sn), rval);
break;
case JSOP_SETLOCAL:
case JSOP_SETLOCALPOP:
if (IsVarSlot(jp, pc, &i)) {
atom = GetArgOrVarAtom(jp, i);
LOCAL_ASSERT(atom);
goto do_setname;
}
lval = GetLocal(ss, i);
rval = POP_STR();
goto do_setlval;
case JSOP_INCLOCAL:
case JSOP_DECLOCAL:
if (IsVarSlot(jp, pc, &i)) {
atom = GetArgOrVarAtom(jp, i);
LOCAL_ASSERT(atom);
goto do_incatom;
}
lval = GetLocal(ss, i);
goto do_inclval;
case JSOP_LOCALINC:
case JSOP_LOCALDEC:
if (IsVarSlot(jp, pc, &i)) {
atom = GetArgOrVarAtom(jp, i);
LOCAL_ASSERT(atom);
goto do_atominc;
}
lval = GetLocal(ss, i);
goto do_lvalinc;
case JSOP_RETRVAL:
todo = -2;
break;
case JSOP_RETURN:
LOCAL_ASSERT(jp->fun);
fun = jp->fun;
if (fun->flags & JSFUN_EXPR_CLOSURE) {
/* Turn on parens around comma-expression here. */
op = JSOP_SETNAME;
rval = POP_STR();
js_printf(jp, (*rval == '{') ? "(%s)%s" : ss_format,
rval,
((fun->flags & JSFUN_LAMBDA) || !fun->atom)
? ""
: ";");
todo = -2;
break;
}
/* FALL THROUGH */
case JSOP_SETRVAL:
rval = POP_STR();
if (*rval != '\0')
js_printf(jp, "\t%s %s;\n", js_return_str, rval);
else
js_printf(jp, "\t%s;\n", js_return_str);
todo = -2;
break;
#if JS_HAS_GENERATORS
case JSOP_YIELD:
#if JS_HAS_GENERATOR_EXPRS
if (!ss->inGenExp || !(sn = js_GetSrcNote(jp->script, pc)))
#endif
{
/* Turn off most parens. */
op = JSOP_SETNAME;
rval = POP_STR();
todo = (*rval != '\0')
? Sprint(&ss->sprinter,
(strncmp(rval, js_yield_str, 5) == 0 &&
(rval[5] == ' ' || rval[5] == '\0'))
? "%s (%s)"
: "%s %s",
js_yield_str, rval)
: SprintCString(&ss->sprinter, js_yield_str);
break;
}
#if JS_HAS_GENERATOR_EXPRS
LOCAL_ASSERT(SN_TYPE(sn) == SRC_HIDDEN);
/* FALL THROUGH */
#endif
case JSOP_ARRAYPUSH:
{
/* Turn off most parens. */
op = JSOP_SETNAME;
/* Pop the expression being pushed or yielded. */
rval = POP_STR();
/*
* Skip the for loop head stacked by JSOP_GOTO:SRC_FOR_IN until
* we hit a block local slot (note empty destructuring patterns
* result in unit-count blocks).
*/
uintN pos = ss->top;
while (pos != 0) {
op = (JSOp) ss->opcodes[--pos];
if (op == JSOP_ENTERBLOCK)
break;
}
JS_ASSERT(op == JSOP_ENTERBLOCK);
/*
* Here, forpos must index the space before the left-most |for|
* in the single string of accumulated |for| heads and optional
* final |if (condition)|.
*/
uintN forpos = pos + 1;
LOCAL_ASSERT(forpos < ss->top);
/*
* Now move pos downward over the block's local slots. Even an
* empty destructuring pattern has one (dummy) local.
*/
while (ss->opcodes[pos] == JSOP_ENTERBLOCK) {
if (pos == 0)
break;
--pos;
}
#if JS_HAS_GENERATOR_EXPRS
if (saveop == JSOP_YIELD) {
/*
* Generator expression: decompile just rval followed by
* the string starting at forpos. Leave the result string
* in ss->offsets[0] so it can be recovered by our caller
* (the JSOP_ANONFUNOBJ with SRC_GENEXP case). Bump the
* top of stack to balance yield, which is an expression
* (so has neutral stack balance).
*/
LOCAL_ASSERT(pos == 0);
xval = OFF2STR(&ss->sprinter, ss->offsets[forpos]);
ss->sprinter.offset = PAREN_SLOP;
todo = Sprint(&ss->sprinter, ss_format, rval, xval);
if (todo < 0)
return NULL;
ss->offsets[0] = todo;
++ss->top;
return pc;
}
#endif /* JS_HAS_GENERATOR_EXPRS */
/*
* Array comprehension: retract the sprinter to the beginning
* of the array initialiser and decompile "[<rval> for ...]".
*/
JS_ASSERT(jp->script->nfixed + pos == GET_UINT16(pc));
LOCAL_ASSERT(ss->opcodes[pos] == JSOP_NEWINIT);
ptrdiff_t start = ss->offsets[pos];
LOCAL_ASSERT(ss->sprinter.base[start] == '[' ||
ss->sprinter.base[start] == '#');
LOCAL_ASSERT(forpos < ss->top);
xval = OFF2STR(&ss->sprinter, ss->offsets[forpos]);
lval = OFF2STR(&ss->sprinter, start);
RETRACT(&ss->sprinter, lval);
todo = Sprint(&ss->sprinter, sss_format, lval, rval, xval);
if (todo < 0)
return NULL;
ss->offsets[pos] = todo;
todo = -2;
break;
}
#endif /* JS_HAS_GENERATORS */
case JSOP_THROWING:
todo = -2;
break;
case JSOP_THROW:
sn = js_GetSrcNote(jp->script, pc);
todo = -2;
if (sn && SN_TYPE(sn) == SRC_HIDDEN)
break;
rval = POP_STR();
js_printf(jp, "\t%s %s;\n", js_throw_str, rval);
break;
case JSOP_ITER:
foreach = (pc[1] & (JSITER_FOREACH | JSITER_KEYVALUE)) ==
JSITER_FOREACH;
todo = -2;
break;
case JSOP_MOREITER:
JS_NOT_REACHED("JSOP_MOREITER");
break;
case JSOP_ENDITER:
sn = js_GetSrcNote(jp->script, pc);
todo = -2;
if (sn && SN_TYPE(sn) == SRC_HIDDEN)
break;
(void) PopOff(ss, op);
break;
case JSOP_GOTO:
case JSOP_GOTOX:
sn = js_GetSrcNote(jp->script, pc);
switch (sn ? SN_TYPE(sn) : SRC_NULL) {
case SRC_FOR_IN:
/*
* The bytecode around pc looks like this:
* <<RHS>>
* iter
* pc: goto/gotox C [src_for_in(B, D)]
* A: trace
* iternext
* <<LHS = result_of_iternext>>
* B: pop [maybe a src_decl_var/let]
* <<S>>
* C: moreiter
* ifne/ifnex A
* enditer
* D: ...
*
* In an array comprehension or generator expression, we
* construct the for-head and store it in the slot pushed
* by JSOP_ITER, then recurse to decompile S. The
* culminating JSOP_ARRAYPUSH or JSOP_YIELD instruction
* (which S must contain, by construction) glues all the
* clauses together.
*
* Otherwise this is a for-in statement. We eagerly output
* the for-head and recurse to decompile the controlled
* statement S.
*
* We never decompile the obligatory JSOP_POP,
* JSOP_MOREITER or JSOP_IFNE, though we do quick asserts
* to check that they are there.
*/
LOCAL_ASSERT(pc[-JSOP_ITER_LENGTH] == JSOP_ITER);
LOCAL_ASSERT(pc[js_CodeSpec[op].length] == JSOP_TRACE);
LOCAL_ASSERT(pc[js_CodeSpec[op].length + JSOP_TRACE_LENGTH] == JSOP_ITERNEXT);
cond = GetJumpOffset(pc, pc);
next = js_GetSrcNoteOffset(sn, 0);
tail = js_GetSrcNoteOffset(sn, 1);
LOCAL_ASSERT(pc[next] == JSOP_POP);
LOCAL_ASSERT(pc[cond] == JSOP_MOREITER);
DECOMPILE_CODE(pc + oplen, next - oplen);
lval = POP_STR();
/*
* This string "<next>" comes from jsopcode.tbl. It stands
* for the result pushed by JSOP_ITERNEXT.
*/
LOCAL_ASSERT(strcmp(lval + strlen(lval) - 9, " = <next>") == 0);
const_cast<char *>(lval)[strlen(lval) - 9] = '\0';
LOCAL_ASSERT(ss->top >= 1);
if (ss->inArrayInit || ss->inGenExp) {
rval = POP_STR();
if (ss->top >= 1 && ss->opcodes[ss->top - 1] == JSOP_FORLOCAL) {
ss->sprinter.offset = ss->offsets[ss->top] - PAREN_SLOP;
if (Sprint(&ss->sprinter, " %s (%s in %s)",
foreach ? js_for_each_str : js_for_str,
lval, rval) < 0) {
return NULL;
}
/*
* Do not AddParentSlop here, as we will push the
* top-most offset again, which will add paren slop
* for us. We must push to balance the stack budget
* when nesting for heads in a comprehension.
*/
todo = ss->offsets[ss->top - 1];
} else {
todo = Sprint(&ss->sprinter, " %s (%s in %s)",
foreach ? js_for_each_str : js_for_str,
lval, rval);
}
if (todo < 0 || !PushOff(ss, todo, JSOP_FORLOCAL))
return NULL;
DECOMPILE_CODE(pc + next + JSOP_POP_LENGTH, cond - next - JSOP_POP_LENGTH);
} else {
/*
* As above, rval or an extension of it must remain
* stacked during loop body decompilation.
*/
rval = GetStr(ss, ss->top - 1);
xval = VarPrefix(js_GetSrcNote(jp->script, pc + next));
js_printf(jp, "\t%s (%s%s in %s) {\n",
foreach ? js_for_each_str : js_for_str,
xval, lval, rval);
jp->indent += 4;
DECOMPILE_CODE(pc + next + JSOP_POP_LENGTH, cond - next - JSOP_POP_LENGTH);
jp->indent -= 4;
js_printf(jp, "\t}\n");
}
pc += tail;
LOCAL_ASSERT(*pc == JSOP_IFNE || *pc == JSOP_IFNEX);
len = js_CodeSpec[*pc].length;
break;
case SRC_WHILE:
cond = GetJumpOffset(pc, pc);
tail = js_GetSrcNoteOffset(sn, 0);
DECOMPILE_CODE(pc + cond, tail - cond);
js_printf(jp, "\twhile (%s) {\n", POP_COND_STR());
jp->indent += 4;
DECOMPILE_CODE(pc + oplen, cond - oplen);
jp->indent -= 4;
js_printf(jp, "\t}\n");
pc += tail;
LOCAL_ASSERT(*pc == JSOP_IFNE || *pc == JSOP_IFNEX);
len = js_CodeSpec[*pc].length;
todo = -2;
break;
case SRC_CONT2LABEL:
GET_SOURCE_NOTE_ATOM(sn, atom);
rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
js_printf(jp, "\tcontinue %s;\n", rval);
break;
case SRC_CONTINUE:
js_printf(jp, "\tcontinue;\n");
break;
case SRC_BREAK2LABEL:
GET_SOURCE_NOTE_ATOM(sn, atom);
rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
js_printf(jp, "\tbreak %s;\n", rval);
break;
case SRC_HIDDEN:
break;
default:
js_printf(jp, "\tbreak;\n");
break;
}
todo = -2;
break;
case JSOP_IFEQ:
case JSOP_IFEQX:
{
JSBool elseif = JS_FALSE;
if_again:
len = GetJumpOffset(pc, pc);
sn = js_GetSrcNote(jp->script, pc);
switch (sn ? SN_TYPE(sn) : SRC_NULL) {
case SRC_IF:
case SRC_IF_ELSE:
rval = POP_COND_STR();
if (ss->inArrayInit || ss->inGenExp) {
LOCAL_ASSERT(SN_TYPE(sn) == SRC_IF);
ss->sprinter.offset -= PAREN_SLOP;
if (Sprint(&ss->sprinter, " if (%s)", rval) < 0)
return NULL;
AddParenSlop(ss);
} else {
js_printf(jp,
elseif ? " if (%s) {\n" : "\tif (%s) {\n",
rval);
jp->indent += 4;
}
if (SN_TYPE(sn) == SRC_IF) {
DECOMPILE_CODE(pc + oplen, len - oplen);
} else {
LOCAL_ASSERT(!ss->inArrayInit && !ss->inGenExp);
tail = js_GetSrcNoteOffset(sn, 0);
DECOMPILE_CODE(pc + oplen, tail - oplen);
jp->indent -= 4;
pc += tail;
LOCAL_ASSERT(*pc == JSOP_GOTO || *pc == JSOP_GOTOX);
oplen = js_CodeSpec[*pc].length;
len = GetJumpOffset(pc, pc);
js_printf(jp, "\t} else");
/*
* If the second offset for sn is non-zero, it tells
* the distance from the goto around the else, to the
* ifeq for the if inside the else that forms an "if
* else if" chain. Thus cond spans the condition of
* the second if, so we simply decompile it and start
* over at label if_again.
*/
cond = js_GetSrcNoteOffset(sn, 1);
if (cond != 0) {
cond -= tail;
DECOMPILE_CODE(pc + oplen, cond - oplen);
pc += cond;
oplen = js_CodeSpec[*pc].length;
elseif = JS_TRUE;
goto if_again;
}
js_printf(jp, " {\n");
jp->indent += 4;
DECOMPILE_CODE(pc + oplen, len - oplen);
}
if (!ss->inArrayInit && !ss->inGenExp) {
jp->indent -= 4;
js_printf(jp, "\t}\n");
}
todo = -2;
break;
case SRC_COND:
xval = JS_strdup(cx, POP_STR());
if (!xval)
return NULL;
len = js_GetSrcNoteOffset(sn, 0);
lval = NULL;
DECOMPILE_CODE_CLEANUP(pc + oplen, len - oplen, goto src_cond_error);
lval = JS_strdup(cx, POP_STR());
if (!lval) goto src_cond_error;
pc += len;
LOCAL_ASSERT(*pc == JSOP_GOTO || *pc == JSOP_GOTOX);
oplen = js_CodeSpec[*pc].length;
len = GetJumpOffset(pc, pc);
DECOMPILE_CODE_CLEANUP(pc + oplen, len - oplen, goto src_cond_error);
rval = POP_STR();
todo = Sprint(&ss->sprinter, "%s ? %s : %s",
xval, lval, rval);
cx->free_((void *)xval);
cx->free_((void *)lval);
break;
src_cond_error:
cx->free_((void *)xval);
if (lval)
cx->free_((void *)lval);
return NULL;
default:
break;
}
break;
}
case JSOP_IFNE:
case JSOP_IFNEX:
LOCAL_ASSERT(0);
break;
case JSOP_OR:
case JSOP_ORX:
xval = "||";
do_logical_connective:
/* Top of stack is the first clause in a disjunction (||). */
lval = JS_strdup(cx, POP_STR());
if (!lval)
return NULL;
done = pc + GetJumpOffset(pc, pc);
pc += len;
len = done - pc;
if (!Decompile(ss, pc, len, op)) {
cx->free_((char *)lval);
return NULL;
}
rval = POP_STR();
if (jp->pretty &&
jp->indent + 4 + strlen(lval) + 4 + strlen(rval) > 75) {
rval = JS_strdup(cx, rval);
if (!rval) {
tail = -1;
} else {
todo = Sprint(&ss->sprinter, "%s %s\n", lval, xval);
tail = Sprint(&ss->sprinter, "%*s%s",
jp->indent + 4, "", rval);
cx->free_((char *)rval);
}
if (tail < 0)
todo = -1;
} else {
todo = Sprint(&ss->sprinter, "%s %s %s", lval, xval, rval);
}
cx->free_((char *)lval);
break;
case JSOP_AND:
case JSOP_ANDX:
xval = "&&";
goto do_logical_connective;
case JSOP_ENUMELEM:
case JSOP_ENUMCONSTELEM:
/*
* The stack has the object under the (top) index expression.
* The "rval" property id is underneath those two on the stack.
* The for loop body net and gross lengths can now be adjusted
* to account for the length of the indexing expression that
* came after JSOP_FORELEM and before JSOP_ENUMELEM.
*/
atom = NULL;
op = JSOP_NOP; /* turn off parens around xval */
xval = POP_STR();
op = JSOP_GETELEM; /* lval must have high precedence */
lval = POP_STR();
op = saveop;
rval = POP_STR();
LOCAL_ASSERT(strcmp(rval, forelem_cookie) == 0);
if (*xval == '\0') {
todo = SprintCString(&ss->sprinter, lval);
} else {
todo = Sprint(&ss->sprinter,
(JOF_OPMODE(lastop) == JOF_XMLNAME)
? dot_format
: index_format,
lval, xval);
}
break;
case JSOP_GETTER:
case JSOP_SETTER:
todo = -2;
break;
case JSOP_DUP2:
rval = GetStr(ss, ss->top-2);
todo = SprintCString(&ss->sprinter, rval);
if (todo < 0 || !PushOff(ss, todo,
(JSOp) ss->opcodes[ss->top-2])) {
return NULL;
}
/* FALL THROUGH */
case JSOP_DUP:
#if JS_HAS_DESTRUCTURING
sn = js_GetSrcNote(jp->script, pc);
if (sn) {
LOCAL_ASSERT(SN_TYPE(sn) == SRC_DESTRUCT);
pc = DecompileDestructuring(ss, pc, endpc);
if (!pc)
return NULL;
len = 0;
lval = POP_STR();
op = saveop = JSOP_ENUMELEM;
rval = POP_STR();
if (strcmp(rval, forelem_cookie) == 0) {
todo = Sprint(&ss->sprinter, ss_format,
VarPrefix(sn), lval);
// Skip POP so the SRC_FOR_IN code can pop for itself.
if (*pc == JSOP_POP)
len = JSOP_POP_LENGTH;
} else {
todo = Sprint(&ss->sprinter, "%s%s = %s",
VarPrefix(sn), lval, rval);
}
break;
}
#endif
rval = GetStr(ss, ss->top-1);
saveop = (JSOp) ss->opcodes[ss->top-1];
todo = SprintCString(&ss->sprinter, rval);
break;
case JSOP_SETARG:
atom = GetArgOrVarAtom(jp, GET_ARGNO(pc));
LOCAL_ASSERT(atom);
goto do_setname;
case JSOP_SETCONST:
case JSOP_SETNAME:
case JSOP_SETGNAME:
LOAD_ATOM(0);
do_setname:
lval = QuoteString(&ss->sprinter, atom, 0);
if (!lval)
return NULL;
rval = POP_STR();
if (op == JSOP_SETNAME || op == JSOP_SETGNAME)
(void) PopOff(ss, op);
do_setlval:
sn = js_GetSrcNote(jp->script, pc - 1);
if (sn && SN_TYPE(sn) == SRC_ASSIGNOP) {
todo = Sprint(&ss->sprinter, "%s %s= %s",
lval,
(lastop == JSOP_GETTER)
? js_getter_str
: (lastop == JSOP_SETTER)
? js_setter_str
: CodeToken[lastop],
rval);
} else {
sn = js_GetSrcNote(jp->script, pc);
todo = Sprint(&ss->sprinter, "%s%s = %s",
VarPrefix(sn), lval, rval);
}
if (op == JSOP_SETLOCALPOP) {
if (!PushOff(ss, todo, saveop))
return NULL;
rval = POP_STR();
LOCAL_ASSERT(*rval != '\0');
js_printf(jp, "\t%s;\n", rval);
todo = -2;
}
break;
case JSOP_NEW:
case JSOP_CALL:
case JSOP_EVAL:
case JSOP_FUNCALL:
case JSOP_FUNAPPLY:
argc = GET_ARGC(pc);
argv = (char **)
cx->malloc_((size_t)(argc + 1) * sizeof *argv);
if (!argv)
return NULL;
op = JSOP_SETNAME;
ok = JS_TRUE;
for (i = argc; i > 0; i--)
argv[i] = JS_strdup(cx, POP_STR());
/* Skip the JSOP_PUSHOBJ-created empty string. */
LOCAL_ASSERT(ss->top >= 2);
(void) PopOff(ss, op);
/*
* Special case: new (x(y)(z)) must be parenthesized like so.
* Same for new (x(y).z) -- contrast with new x(y).z.
* See PROPAGATE_CALLNESS.
*/
op = (JSOp) ss->opcodes[ss->top - 1];
lval = PopStr(ss,
(saveop == JSOP_NEW &&
(op == JSOP_CALL ||
op == JSOP_EVAL ||
op == JSOP_FUNCALL ||
op == JSOP_FUNAPPLY ||
(js_CodeSpec[op].format & JOF_CALLOP)))
? JSOP_NAME
: saveop);
op = saveop;
argv[0] = JS_strdup(cx, lval);
if (!argv[0])
ok = JS_FALSE;
lval = "(", rval = ")";
if (op == JSOP_NEW) {
if (argc == 0)
lval = rval = "";
todo = Sprint(&ss->sprinter, "%s %s%s",
js_new_str, argv[0], lval);
} else {
todo = Sprint(&ss->sprinter, ss_format,
argv[0], lval);
}
if (todo < 0)
ok = JS_FALSE;
for (i = 1; i <= argc; i++) {
if (!argv[i] ||
Sprint(&ss->sprinter, ss_format,
argv[i], (i < argc) ? ", " : "") < 0) {
ok = JS_FALSE;
break;
}
}
if (Sprint(&ss->sprinter, rval) < 0)
ok = JS_FALSE;
for (i = 0; i <= argc; i++)
cx->free_(argv[i]);
cx->free_(argv);
if (!ok)
return NULL;
break;
case JSOP_SETCALL:
todo = Sprint(&ss->sprinter, "");
break;
case JSOP_DELNAME:
LOAD_ATOM(0);
lval = QuoteString(&ss->sprinter, atom, 0);
if (!lval)
return NULL;
RETRACT(&ss->sprinter, lval);
do_delete_lval:
todo = Sprint(&ss->sprinter, "%s %s", js_delete_str, lval);
break;
case JSOP_DELPROP:
GET_ATOM_QUOTE_AND_FMT("%s %s[%s]", "%s %s.%s", rval);
op = JSOP_GETPROP;
lval = POP_STR();
todo = Sprint(&ss->sprinter, fmt, js_delete_str, lval, rval);
break;
case JSOP_DELELEM:
op = JSOP_NOP; /* turn off parens */
xval = POP_STR();
op = JSOP_GETPROP;
lval = POP_STR();
if (*xval == '\0')
goto do_delete_lval;
todo = Sprint(&ss->sprinter,
(JOF_OPMODE(lastop) == JOF_XMLNAME)
? "%s %s.%s"
: "%s %s[%s]",
js_delete_str, lval, xval);
break;
#if JS_HAS_XML_SUPPORT
case JSOP_DELDESC:
xval = POP_STR();
op = JSOP_GETPROP;
lval = POP_STR();
todo = Sprint(&ss->sprinter, "%s %s..%s",
js_delete_str, lval, xval);
break;
#endif
case JSOP_TYPEOFEXPR:
case JSOP_TYPEOF:
case JSOP_VOID:
rval = POP_STR();
todo = Sprint(&ss->sprinter, "%s %s",
(op == JSOP_VOID) ? js_void_str : js_typeof_str,
rval);
break;
case JSOP_INCARG:
case JSOP_DECARG:
atom = GetArgOrVarAtom(jp, GET_ARGNO(pc));
LOCAL_ASSERT(atom);
goto do_incatom;
case JSOP_INCNAME:
case JSOP_DECNAME:
case JSOP_INCGNAME:
case JSOP_DECGNAME:
LOAD_ATOM(0);
do_incatom:
lval = QuoteString(&ss->sprinter, atom, 0);
if (!lval)
return NULL;
RETRACT(&ss->sprinter, lval);
do_inclval:
todo = Sprint(&ss->sprinter, ss_format,
js_incop_strs[!(cs->format & JOF_INC)], lval);
if (js_CodeSpec[*pc].format & JOF_DECOMPOSE)
len += GetDecomposeLength(pc, js_CodeSpec[*pc].length);
break;
case JSOP_INCPROP:
case JSOP_DECPROP:
GET_ATOM_QUOTE_AND_FMT(preindex_format, predot_format, rval);
/*
* Force precedence below the numeric literal opcodes, so that
* 42..foo or 10000..toString(16), e.g., decompile with parens
* around the left-hand side of dot.
*/
op = JSOP_GETPROP;
lval = POP_STR();
todo = Sprint(&ss->sprinter, fmt,
js_incop_strs[!(cs->format & JOF_INC)],
lval, rval);
len += GetDecomposeLength(pc, JSOP_INCPROP_LENGTH);
break;
case JSOP_INCELEM:
case JSOP_DECELEM:
op = JSOP_NOP; /* turn off parens */
xval = POP_STR();
op = JSOP_GETELEM;
lval = POP_STR();
if (*xval != '\0') {
todo = Sprint(&ss->sprinter,
(JOF_OPMODE(lastop) == JOF_XMLNAME)
? predot_format
: preindex_format,
js_incop_strs[!(cs->format & JOF_INC)],
lval, xval);
} else {
todo = Sprint(&ss->sprinter, ss_format,
js_incop_strs[!(cs->format & JOF_INC)], lval);
}
len += GetDecomposeLength(pc, JSOP_INCELEM_LENGTH);
break;
case JSOP_ARGINC:
case JSOP_ARGDEC:
atom = GetArgOrVarAtom(jp, GET_ARGNO(pc));
LOCAL_ASSERT(atom);
goto do_atominc;
case JSOP_NAMEINC:
case JSOP_NAMEDEC:
case JSOP_GNAMEINC:
case JSOP_GNAMEDEC:
LOAD_ATOM(0);
do_atominc:
lval = QuoteString(&ss->sprinter, atom, 0);
if (!lval)
return NULL;
RETRACT(&ss->sprinter, lval);
do_lvalinc:
todo = Sprint(&ss->sprinter, ss_format,
lval, js_incop_strs[!(cs->format & JOF_INC)]);
if (js_CodeSpec[*pc].format & JOF_DECOMPOSE)
len += GetDecomposeLength(pc, js_CodeSpec[*pc].length);
break;
case JSOP_PROPINC:
case JSOP_PROPDEC:
GET_ATOM_QUOTE_AND_FMT(postindex_format, postdot_format, rval);
/*
* Force precedence below the numeric literal opcodes, so that
* 42..foo or 10000..toString(16), e.g., decompile with parens
* around the left-hand side of dot.
*/
op = JSOP_GETPROP;
lval = POP_STR();
todo = Sprint(&ss->sprinter, fmt, lval, rval,
js_incop_strs[!(cs->format & JOF_INC)]);
len += GetDecomposeLength(pc, JSOP_PROPINC_LENGTH);
break;
case JSOP_ELEMINC:
case JSOP_ELEMDEC:
op = JSOP_NOP; /* turn off parens */
xval = POP_STR();
op = JSOP_GETELEM;
lval = POP_STR();
if (*xval != '\0') {
todo = Sprint(&ss->sprinter,
(JOF_OPMODE(lastop) == JOF_XMLNAME)
? postdot_format
: postindex_format,
lval, xval,
js_incop_strs[!(cs->format & JOF_INC)]);
} else {
todo = Sprint(&ss->sprinter, ss_format,
lval, js_incop_strs[!(cs->format & JOF_INC)]);
}
len += GetDecomposeLength(pc, JSOP_ELEMINC_LENGTH);
break;
case JSOP_GETPROP2:
op = JSOP_GETPROP;
(void) PopOff(ss, lastop);
/* FALL THROUGH */
case JSOP_CALLPROP:
case JSOP_GETPROP:
case JSOP_GETXPROP:
case JSOP_LENGTH:
LOAD_ATOM(0);
GET_QUOTE_AND_FMT(index_format, dot_format, rval);
PROPAGATE_CALLNESS();
lval = POP_STR();
todo = Sprint(&ss->sprinter, fmt, lval, rval);
break;
case JSOP_SETPROP:
case JSOP_SETMETHOD:
LOAD_ATOM(0);
GET_QUOTE_AND_FMT("%s[%s] %s= %s", "%s.%s %s= %s", xval);
rval = POP_STR();
/*
* Force precedence below the numeric literal opcodes, so that
* 42..foo or 10000..toString(16), e.g., decompile with parens
* around the left-hand side of dot.
*/
op = JSOP_GETPROP;
lval = POP_STR();
sn = js_GetSrcNote(jp->script, pc - 1);
todo = Sprint(&ss->sprinter, fmt, lval, xval,
(sn && SN_TYPE(sn) == SRC_ASSIGNOP)
? (lastop == JSOP_GETTER)
? js_getter_str
: (lastop == JSOP_SETTER)
? js_setter_str
: CodeToken[lastop]
: "",
rval);
break;
case JSOP_GETELEM2:
op = JSOP_GETELEM;
(void) PopOff(ss, lastop);
/* FALL THROUGH */
case JSOP_CALLELEM:
case JSOP_GETELEM:
op = JSOP_NOP; /* turn off parens */
xval = POP_STR();
op = saveop;
PROPAGATE_CALLNESS();
lval = POP_STR();
if (*xval == '\0') {
todo = Sprint(&ss->sprinter, "%s", lval);
} else {
todo = Sprint(&ss->sprinter,
(JOF_OPMODE(lastop) == JOF_XMLNAME)
? dot_format
: index_format,
lval, xval);
}
break;
case JSOP_SETELEM:
case JSOP_SETHOLE:
rval = POP_STR();
op = JSOP_NOP; /* turn off parens */
xval = POP_STR();
cs = &js_CodeSpec[ss->opcodes[ss->top]];
op = JSOP_GETELEM; /* lval must have high precedence */
lval = POP_STR();
op = saveop;
if (*xval == '\0')
goto do_setlval;
sn = js_GetSrcNote(jp->script, pc - 1);
todo = Sprint(&ss->sprinter,
(JOF_MODE(cs->format) == JOF_XMLNAME)
? "%s.%s %s= %s"
: "%s[%s] %s= %s",
lval, xval,
(sn && SN_TYPE(sn) == SRC_ASSIGNOP)
? (lastop == JSOP_GETTER)
? js_getter_str
: (lastop == JSOP_SETTER)
? js_setter_str
: CodeToken[lastop]
: "",
rval);
break;
case JSOP_ARGSUB:
i = (jsint) GET_ARGNO(pc);
todo = Sprint(&ss->sprinter, "%s[%d]",
js_arguments_str, (int) i);
break;
case JSOP_ARGCNT:
todo = Sprint(&ss->sprinter, dot_format,
js_arguments_str, js_length_str);
break;
case JSOP_CALLARG:
case JSOP_GETARG:
i = GET_ARGNO(pc);
atom = GetArgOrVarAtom(jp, i);
#if JS_HAS_DESTRUCTURING
if (!atom) {
todo = Sprint(&ss->sprinter, "%s[%d]", js_arguments_str, i);
break;
}
#else
LOCAL_ASSERT(atom);
#endif
goto do_name;
case JSOP_CALLGLOBAL:
case JSOP_GETGLOBAL:
atom = jp->script->getGlobalAtom(GET_SLOTNO(pc));
goto do_name;
case JSOP_CALLNAME:
case JSOP_NAME:
case JSOP_GETGNAME:
case JSOP_CALLGNAME:
LOAD_ATOM(0);
do_name:
lval = "";
#if JS_HAS_XML_SUPPORT
do_qname:
#endif
sn = js_GetSrcNote(jp->script, pc);
rval = QuoteString(&ss->sprinter, atom, inXML ? DONT_ESCAPE : 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
todo = Sprint(&ss->sprinter, sss_format,
VarPrefix(sn), lval, rval);
break;
case JSOP_UINT16:
i = (jsint) GET_UINT16(pc);
goto do_sprint_int;
case JSOP_UINT24:
i = (jsint) GET_UINT24(pc);
goto do_sprint_int;
case JSOP_INT8:
i = GET_INT8(pc);
goto do_sprint_int;
case JSOP_INT32:
i = GET_INT32(pc);
do_sprint_int:
todo = Sprint(&ss->sprinter, "%d", i);
break;
case JSOP_DOUBLE:
{
double d;
GET_DOUBLE_FROM_BYTECODE(jp->script, pc, 0, d);
val = DOUBLE_TO_JSVAL(d);
todo = SprintDoubleValue(&ss->sprinter, val, &saveop);
break;
}
case JSOP_STRING:
LOAD_ATOM(0);
rval = QuoteString(&ss->sprinter, atom, inXML ? DONT_ESCAPE : '"');
if (!rval)
return NULL;
todo = STR2OFF(&ss->sprinter, rval);
break;
case JSOP_LAMBDA:
case JSOP_LAMBDA_FC:
#if JS_HAS_GENERATOR_EXPRS
sn = js_GetSrcNote(jp->script, pc);
if (sn && SN_TYPE(sn) == SRC_GENEXP) {
void *mark;
Vector<JSAtom *> *innerLocalNames;
Vector<JSAtom *> *outerLocalNames;
JSScript *inner, *outer;
SprintStack ss2;
JSFunction *outerfun;
LOAD_FUNCTION(0);
/*
* All allocation when decompiling is LIFO, using malloc
* or, more commonly, arena-allocating from cx->tempPool.
* Therefore after InitSprintStack succeeds, we must
* release to mark before returning.
*/
mark = JS_ARENA_MARK(&cx->tempPool);
if (fun->script()->bindings.hasLocalNames()) {
innerLocalNames = cx->new_<Vector<JSAtom *> >(cx);
if (!innerLocalNames ||
fun->script()->bindings.getLocalNameArray(cx, innerLocalNames))
{
return NULL;
}
} else {
innerLocalNames = NULL;
}
inner = fun->script();
if (!InitSprintStack(cx, &ss2, jp, StackDepth(inner))) {
JS_ARENA_RELEASE(&cx->tempPool, mark);
return NULL;
}
ss2.inGenExp = JS_TRUE;
/*
* Recursively decompile this generator function as an
* un-parenthesized generator expression. The ss->inGenExp
* special case of JSOP_YIELD shares array comprehension
* decompilation code that leaves the result as the single
* string pushed on ss2.
*/
outer = jp->script;
outerfun = jp->fun;
outerLocalNames = jp->localNames;
LOCAL_ASSERT(JS_UPTRDIFF(pc, outer->code) <= outer->length);
jp->script = inner;
jp->fun = fun;
jp->localNames = innerLocalNames;
/*
* Decompile only the main bytecode, to avoid tripping over
* new prolog ops that have stack effects.
*/
ok = Decompile(&ss2, inner->main(), inner->length - inner->mainOffset,
JSOP_NOP)
!= NULL;
jp->script = outer;
jp->fun = outerfun;
jp->localNames = outerLocalNames;
if (!ok) {
JS_ARENA_RELEASE(&cx->tempPool, mark);
return NULL;
}
/*
* Advance over this op and its global |this| push, and
* arrange to advance over the call to this lambda.
*/
pc += len;
if (*pc == JSOP_BLOCKCHAIN) {
pc += JSOP_BLOCKCHAIN_LENGTH;
} else {
LOCAL_ASSERT(*pc == JSOP_NULLBLOCKCHAIN);
pc += JSOP_NULLBLOCKCHAIN_LENGTH;
}
LOCAL_ASSERT(*pc == JSOP_PUSH);
pc += JSOP_PUSH_LENGTH;
LOCAL_ASSERT(*pc == JSOP_CALL);
LOCAL_ASSERT(GET_ARGC(pc) == 0);
len = JSOP_CALL_LENGTH;
/*
* Arrange to parenthesize this genexp unless:
*
* 1. It is the complete expression consumed by a control
* flow bytecode such as JSOP_TABLESWITCH whose syntax
* always parenthesizes the controlling expression.
* 2. It is the sole argument to a function call.
*
* But if this genexp runs up against endpc, parenthesize
* regardless. (This can happen if we are called from
* DecompileExpression or recursively from case
* JSOP_{NOP,AND,OR}.)
*
* There's no special case for |if (genexp)| because the
* compiler optimizes that to |if (true)|.
*/
pc2 = pc + len;
op = JSOp(*pc2);
if (op == JSOP_TRACE || op == JSOP_NOP)
pc2 += JSOP_NOP_LENGTH;
LOCAL_ASSERT(pc2 < endpc ||
endpc < outer->code + outer->length);
LOCAL_ASSERT(ss2.top == 1);
ss2.opcodes[0] = JSOP_POP;
if (pc2 == endpc) {
op = JSOP_SETNAME;
} else {
op = (JSOp) *pc2;
op = ((js_CodeSpec[op].format & JOF_PARENHEAD) ||
((js_CodeSpec[op].format & JOF_INVOKE) && GET_ARGC(pc2) == 1))
? JSOP_POP
: JSOP_SETNAME;
/*
* Stack this result as if it's a name and not an
* anonymous function, so it doesn't get decompiled as
* a generator function in a getter or setter context.
* The precedence level is the same for JSOP_NAME and
* JSOP_LAMBDA.
*/
LOCAL_ASSERT(js_CodeSpec[JSOP_NAME].prec ==
js_CodeSpec[saveop].prec);
saveop = JSOP_NAME;
}
/*
* Alas, we have to malloc a copy of the result left on
* the top of ss2 because both ss and ss2 arena-allocate
* from cx's tempPool.
*/
rval = JS_strdup(cx, PopStr(&ss2, op));
JS_ARENA_RELEASE(&cx->tempPool, mark);
if (!rval)
return NULL;
todo = SprintCString(&ss->sprinter, rval);
cx->free_((void *)rval);
break;
}
#endif /* JS_HAS_GENERATOR_EXPRS */
/* FALL THROUGH */
LOAD_FUNCTION(0);
{
/*
* Always parenthesize expression closures. We can't force
* saveop to a low-precedence op to arrange for auto-magic
* parenthesization without confusing getter/setter code
* that checks for JSOP_LAMBDA.
*/
bool grouped = !(fun->flags & JSFUN_EXPR_CLOSURE);
bool strict = jp->script->strictModeCode;
str = js_DecompileToString(cx, "lambda", fun, 0,
false, grouped, strict,
js_DecompileFunction);
if (!str)
return NULL;
}
sprint_string:
todo = SprintString(&ss->sprinter, str);
break;
case JSOP_CALLEE:
JS_ASSERT(jp->fun && jp->fun->atom);
todo = SprintString(&ss->sprinter, jp->fun->atom);
break;
case JSOP_OBJECT:
LOAD_OBJECT(0);
str = js_ValueToSource(cx, ObjectValue(*obj));
if (!str)
return NULL;
goto sprint_string;
case JSOP_REGEXP:
GET_REGEXP_FROM_BYTECODE(jp->script, pc, 0, obj);
if (!js_regexp_toString(cx, obj, Valueify(&val)))
return NULL;
str = JSVAL_TO_STRING(val);
goto sprint_string;
case JSOP_TABLESWITCH:
case JSOP_TABLESWITCHX:
{
ptrdiff_t jmplen, off, off2;
jsint j, n, low, high;
TableEntry *table, *tmp;
sn = js_GetSrcNote(jp->script, pc);
LOCAL_ASSERT(sn && SN_TYPE(sn) == SRC_SWITCH);
len = js_GetSrcNoteOffset(sn, 0);
jmplen = (op == JSOP_TABLESWITCH) ? JUMP_OFFSET_LEN
: JUMPX_OFFSET_LEN;
pc2 = pc;
off = GetJumpOffset(pc, pc2);
pc2 += jmplen;
low = GET_JUMP_OFFSET(pc2);
pc2 += JUMP_OFFSET_LEN;
high = GET_JUMP_OFFSET(pc2);
pc2 += JUMP_OFFSET_LEN;
n = high - low + 1;
if (n == 0) {
table = NULL;
j = 0;
ok = JS_TRUE;
} else {
table = (TableEntry *)
cx->malloc_((size_t)n * sizeof *table);
if (!table)
return NULL;
for (i = j = 0; i < n; i++) {
table[j].label = NULL;
off2 = GetJumpOffset(pc, pc2);
if (off2) {
sn = js_GetSrcNote(jp->script, pc2);
if (sn) {
LOCAL_ASSERT(SN_TYPE(sn) == SRC_LABEL);
GET_SOURCE_NOTE_ATOM(sn, table[j].label);
}
table[j].key = INT_TO_JSVAL(low + i);
table[j].offset = off2;
table[j].order = j;
j++;
}
pc2 += jmplen;
}
tmp = (TableEntry *)
cx->malloc_((size_t)j * sizeof *table);
if (tmp) {
VOUCH_DOES_NOT_REQUIRE_STACK();
ok = js_MergeSort(table, (size_t)j, sizeof(TableEntry),
CompareOffsets, NULL, tmp,
JS_SORTING_GENERIC);
cx->free_(tmp);
} else {
ok = JS_FALSE;
}
}
if (ok) {
ok = DecompileSwitch(ss, table, (uintN)j, pc, len, off,
JS_FALSE);
}
cx->free_(table);
if (!ok)
return NULL;
todo = -2;
break;
}
case JSOP_LOOKUPSWITCH:
case JSOP_LOOKUPSWITCHX:
{
ptrdiff_t jmplen, off, off2;
jsatomid npairs, k;
TableEntry *table;
sn = js_GetSrcNote(jp->script, pc);
LOCAL_ASSERT(sn && SN_TYPE(sn) == SRC_SWITCH);
len = js_GetSrcNoteOffset(sn, 0);
jmplen = (op == JSOP_LOOKUPSWITCH) ? JUMP_OFFSET_LEN
: JUMPX_OFFSET_LEN;
pc2 = pc;
off = GetJumpOffset(pc, pc2);
pc2 += jmplen;
npairs = GET_UINT16(pc2);
pc2 += UINT16_LEN;
table = (TableEntry *)
cx->malloc_((size_t)npairs * sizeof *table);
if (!table)
return NULL;
for (k = 0; k < npairs; k++) {
sn = js_GetSrcNote(jp->script, pc2);
if (sn) {
LOCAL_ASSERT(SN_TYPE(sn) == SRC_LABEL);
GET_SOURCE_NOTE_ATOM(sn, table[k].label);
} else {
table[k].label = NULL;
}
uint16 constIndex = GET_INDEX(pc2);
pc2 += INDEX_LEN;
off2 = GetJumpOffset(pc, pc2);
pc2 += jmplen;
table[k].key = Jsvalify(jp->script->getConst(constIndex));
table[k].offset = off2;
}
ok = DecompileSwitch(ss, table, (uintN)npairs, pc, len, off,
JS_FALSE);
cx->free_(table);
if (!ok)
return NULL;
todo = -2;
break;
}
case JSOP_CONDSWITCH:
{
ptrdiff_t off, off2, caseOff;
jsint ncases;
TableEntry *table;
sn = js_GetSrcNote(jp->script, pc);
LOCAL_ASSERT(sn && SN_TYPE(sn) == SRC_SWITCH);
len = js_GetSrcNoteOffset(sn, 0);
off = js_GetSrcNoteOffset(sn, 1);
/*
* Count the cases using offsets from switch to first case,
* and case to case, stored in srcnote immediates.
*/
pc2 = pc;
off2 = off;
for (ncases = 0; off2 != 0; ncases++) {
pc2 += off2;
LOCAL_ASSERT(*pc2 == JSOP_CASE || *pc2 == JSOP_DEFAULT ||
*pc2 == JSOP_CASEX || *pc2 == JSOP_DEFAULTX);
if (*pc2 == JSOP_DEFAULT || *pc2 == JSOP_DEFAULTX) {
/* End of cases, but count default as a case. */
off2 = 0;
} else {
sn = js_GetSrcNote(jp->script, pc2);
LOCAL_ASSERT(sn && SN_TYPE(sn) == SRC_PCDELTA);
off2 = js_GetSrcNoteOffset(sn, 0);
}
}
/*
* Allocate table and rescan the cases using their srcnotes,
* stashing each case's delta from switch top in table[i].key,
* and the distance to its statements in table[i].offset.
*/
table = (TableEntry *)
cx->malloc_((size_t)ncases * sizeof *table);
if (!table)
return NULL;
pc2 = pc;
off2 = off;
for (i = 0; i < ncases; i++) {
pc2 += off2;
LOCAL_ASSERT(*pc2 == JSOP_CASE || *pc2 == JSOP_DEFAULT ||
*pc2 == JSOP_CASEX || *pc2 == JSOP_DEFAULTX);
caseOff = pc2 - pc;
table[i].key = INT_TO_JSVAL((jsint) caseOff);
table[i].offset = caseOff + GetJumpOffset(pc2, pc2);
if (*pc2 == JSOP_CASE || *pc2 == JSOP_CASEX) {
sn = js_GetSrcNote(jp->script, pc2);
LOCAL_ASSERT(sn && SN_TYPE(sn) == SRC_PCDELTA);
off2 = js_GetSrcNoteOffset(sn, 0);
}
}
/*
* Find offset of default code by fetching the default offset
* from the end of table. JSOP_CONDSWITCH always has a default
* case at the end.
*/
off = JSVAL_TO_INT(table[ncases-1].key);
pc2 = pc + off;
off += GetJumpOffset(pc2, pc2);
ok = DecompileSwitch(ss, table, (uintN)ncases, pc, len, off,
JS_TRUE);
cx->free_(table);
if (!ok)
return NULL;
todo = -2;
break;
}
case JSOP_CASE:
case JSOP_CASEX:
{
lval = POP_STR();
if (!lval)
return NULL;
js_printf(jp, "\tcase %s:\n", lval);
todo = -2;
break;
}
case JSOP_DEFFUN:
case JSOP_DEFFUN_FC:
LOAD_FUNCTION(0);
todo = -2;
goto do_function;
break;
case JSOP_TRAP:
saveop = op = JS_GetTrapOpcode(cx, jp->script, pc);
*pc = op;
cs = &js_CodeSpec[op];
len = cs->length;
DECOMPILE_CODE(pc, len);
if (js_CodeSpec[*pc].format & JOF_DECOMPOSE)
len += GetDecomposeLength(pc, js_CodeSpec[*pc].length);
*pc = JSOP_TRAP;
todo = -2;
break;
case JSOP_HOLE:
todo = SprintPut(&ss->sprinter, "", 0);
break;
case JSOP_NEWINIT:
{
i = pc[1];
LOCAL_ASSERT(i == JSProto_Array || i == JSProto_Object);
todo = ss->sprinter.offset;
#if JS_HAS_SHARP_VARS
op = (JSOp)pc[len];
if (op == JSOP_SHARPINIT)
op = (JSOp)pc[len += JSOP_SHARPINIT_LENGTH];
if (op == JSOP_DEFSHARP) {
pc += len;
cs = &js_CodeSpec[op];
len = cs->length;
if (Sprint(&ss->sprinter, "#%u=",
(unsigned) (jsint) GET_UINT16(pc + UINT16_LEN))
< 0) {
return NULL;
}
}
#endif /* JS_HAS_SHARP_VARS */
if (i == JSProto_Array) {
++ss->inArrayInit;
if (SprintCString(&ss->sprinter, "[") < 0)
return NULL;
} else {
if (SprintCString(&ss->sprinter, "{") < 0)
return NULL;
}
break;
}
case JSOP_NEWARRAY:
{
todo = ss->sprinter.offset;
++ss->inArrayInit;
if (SprintCString(&ss->sprinter, "[") < 0)
return NULL;
break;
}
case JSOP_NEWOBJECT:
{
todo = ss->sprinter.offset;
if (SprintCString(&ss->sprinter, "{") < 0)
return NULL;
break;
}
case JSOP_ENDINIT:
{
JSBool inArray;
op = JSOP_NOP; /* turn off parens */
rval = POP_STR();
sn = js_GetSrcNote(jp->script, pc);
/* Skip any #n= prefix to find the opening bracket. */
for (xval = rval; *xval != '[' && *xval != '{'; xval++)
continue;
inArray = (*xval == '[');
if (inArray)
--ss->inArrayInit;
todo = Sprint(&ss->sprinter, "%s%s%c",
rval,
(sn && SN_TYPE(sn) == SRC_CONTINUE) ? ", " : "",
inArray ? ']' : '}');
break;
}
{
JSBool isFirst;
const char *maybeComma;
case JSOP_INITELEM:
isFirst = IsInitializerOp(ss->opcodes[ss->top - 3]);
/* Turn off most parens. */
op = JSOP_SETNAME;
rval = POP_STR();
/* Turn off all parens for xval and lval, which we control. */
op = JSOP_NOP;
xval = POP_STR();
lval = POP_STR();
sn = js_GetSrcNote(jp->script, pc);
if (sn && SN_TYPE(sn) == SRC_INITPROP) {
atom = NULL;
goto do_initprop;
}
maybeComma = isFirst ? "" : ", ";
todo = Sprint(&ss->sprinter, sss_format,
lval,
maybeComma,
rval);
break;
case JSOP_INITPROP:
case JSOP_INITMETHOD:
LOAD_ATOM(0);
xval = QuoteString(&ss->sprinter, atom,
jschar(ATOM_IS_IDENTIFIER(atom) ? 0 : '\''));
if (!xval)
return NULL;
isFirst = IsInitializerOp(ss->opcodes[ss->top - 2]);
rval = POP_STR();
lval = POP_STR();
/* fall through */
do_initprop:
maybeComma = isFirst ? "" : ", ";
if (lastop == JSOP_GETTER || lastop == JSOP_SETTER) {
const char *end = rval + strlen(rval);
if (*rval == '(')
++rval, --end;
LOCAL_ASSERT(strncmp(rval, js_function_str, 8) == 0);
LOCAL_ASSERT(rval[8] == ' ');
rval += 8 + 1;
LOCAL_ASSERT(*end ? *end == ')' : end[-1] == '}');
todo = Sprint(&ss->sprinter, "%s%s%s %s%s%.*s",
lval,
maybeComma,
(lastop == JSOP_GETTER)
? js_get_str : js_set_str,
xval,
(rval[0] != '(') ? " " : "",
end - rval, rval);
} else {
todo = Sprint(&ss->sprinter, "%s%s%s: %s",
lval, maybeComma, xval, rval);
}
break;
}
#if JS_HAS_SHARP_VARS
case JSOP_DEFSHARP:
i = (jsint) GET_UINT16(pc + UINT16_LEN);
rval = POP_STR();
todo = Sprint(&ss->sprinter, "#%u=%s", (unsigned) i, rval);
break;
case JSOP_USESHARP:
i = (jsint) GET_UINT16(pc + UINT16_LEN);
todo = Sprint(&ss->sprinter, "#%u#", (unsigned) i);
break;
#endif /* JS_HAS_SHARP_VARS */
case JSOP_DEBUGGER:
js_printf(jp, "\tdebugger;\n");
todo = -2;
break;
#if JS_HAS_XML_SUPPORT
case JSOP_STARTXML:
case JSOP_STARTXMLEXPR:
inXML = op == JSOP_STARTXML;
todo = -2;
break;
case JSOP_DEFXMLNS:
rval = POP_STR();
js_printf(jp, "\t%s %s %s = %s;\n",
js_default_str, js_xml_str, js_namespace_str, rval);
todo = -2;
break;
case JSOP_ANYNAME:
if (pc[JSOP_ANYNAME_LENGTH] == JSOP_TOATTRNAME) {
len += JSOP_TOATTRNAME_LENGTH;
todo = SprintPut(&ss->sprinter, "@*", 2);
} else {
todo = SprintPut(&ss->sprinter, "*", 1);
}
break;
case JSOP_QNAMEPART:
LOAD_ATOM(0);
if (pc[JSOP_QNAMEPART_LENGTH] == JSOP_TOATTRNAME) {
saveop = JSOP_TOATTRNAME;
len += JSOP_TOATTRNAME_LENGTH;
lval = "@";
goto do_qname;
}
goto do_name;
case JSOP_QNAMECONST:
LOAD_ATOM(0);
rval = QuoteString(&ss->sprinter, atom, 0);
if (!rval)
return NULL;
RETRACT(&ss->sprinter, rval);
lval = POP_STR();
todo = Sprint(&ss->sprinter, "%s::%s", lval, rval);
break;
case JSOP_QNAME:
rval = POP_STR();
lval = POP_STR();
todo = Sprint(&ss->sprinter, "%s::[%s]", lval, rval);
break;
case JSOP_TOATTRNAME:
op = JSOP_NOP; /* turn off parens */
rval = POP_STR();
todo = Sprint(&ss->sprinter, "@[%s]", rval);
break;
case JSOP_TOATTRVAL:
todo = -2;
break;
case JSOP_ADDATTRNAME:
rval = POP_STR();
lval = POP_STR();
todo = Sprint(&ss->sprinter, "%s %s", lval, rval);
/* This gets reset by all XML tag expressions. */
quoteAttr = JS_TRUE;
break;
case JSOP_ADDATTRVAL:
rval = POP_STR();
lval = POP_STR();
if (quoteAttr)
todo = Sprint(&ss->sprinter, "%s=\"%s\"", lval, rval);
else
todo = Sprint(&ss->sprinter, "%s=%s", lval, rval);
break;
case JSOP_BINDXMLNAME:
/* Leave the name stacked and push a dummy string. */
todo = Sprint(&ss->sprinter, "");
break;
case JSOP_SETXMLNAME:
/* Pop the r.h.s., the dummy string, and the name. */
rval = POP_STR();
(void) PopOff(ss, op);
lval = POP_STR();
goto do_setlval;
case JSOP_XMLELTEXPR:
case JSOP_XMLTAGEXPR:
todo = Sprint(&ss->sprinter, "{%s}", POP_STR());
inXML = JS_TRUE;
/* If we're an attribute value, we shouldn't quote this. */
quoteAttr = JS_FALSE;
break;
case JSOP_TOXMLLIST:
op = JSOP_NOP; /* turn off parens */
todo = Sprint(&ss->sprinter, "<>%s</>", POP_STR());
inXML = JS_FALSE;
break;
case JSOP_TOXML:
case JSOP_CALLXMLNAME:
case JSOP_XMLNAME:
case JSOP_FILTER:
/* These ops indicate the end of XML expressions. */
inXML = JS_FALSE;
todo = -2;
break;
case JSOP_ENDFILTER:
rval = POP_STR();
PROPAGATE_CALLNESS();
lval = POP_STR();
todo = Sprint(&ss->sprinter, "%s.(%s)", lval, rval);
break;
case JSOP_DESCENDANTS:
rval = POP_STR();
PROPAGATE_CALLNESS();
lval = POP_STR();
todo = Sprint(&ss->sprinter, "%s..%s", lval, rval);
break;
case JSOP_XMLCDATA:
LOAD_ATOM(0);
todo = SprintPut(&ss->sprinter, "<![CDATA[", 9);
if (!QuoteString(&ss->sprinter, atom, DONT_ESCAPE))
return NULL;
SprintPut(&ss->sprinter, "]]>", 3);
break;
case JSOP_XMLCOMMENT:
LOAD_ATOM(0);
todo = SprintPut(&ss->sprinter, "<!--", 4);
if (!QuoteString(&ss->sprinter, atom, DONT_ESCAPE))
return NULL;
SprintPut(&ss->sprinter, "-->", 3);
break;
case JSOP_XMLPI:
LOAD_ATOM(0);
rval = JS_strdup(cx, POP_STR());
if (!rval)
return NULL;
todo = SprintPut(&ss->sprinter, "<?", 2);
ok = QuoteString(&ss->sprinter, atom, 0) &&
(*rval == '\0' ||
(SprintPut(&ss->sprinter, " ", 1) >= 0 &&
SprintCString(&ss->sprinter, rval)));
cx->free_((char *)rval);
if (!ok)
return NULL;
SprintPut(&ss->sprinter, "?>", 2);
break;
case JSOP_GETFUNNS:
todo = SprintPut(&ss->sprinter, js_function_str, 8);
break;
#endif /* JS_HAS_XML_SUPPORT */
default:
todo = -2;
break;
}
}
if (todo < 0) {
/* -2 means "don't push", -1 means reported error. */
if (todo == -1)
return NULL;
} else {
if (!PushOff(ss, todo, saveop))
return NULL;
}
if (cs->format & JOF_CALLOP) {
todo = Sprint(&ss->sprinter, "");
if (todo < 0 || !PushOff(ss, todo, saveop))
return NULL;
}
pc += len;
}
/*
* Undefine local macros.
*/
#undef inXML
#undef DECOMPILE_CODE
#undef NEXT_OP
#undef TOP_STR
#undef POP_STR
#undef POP_STR_PREC
#undef LOCAL_ASSERT
#undef ATOM_IS_IDENTIFIER
#undef GET_QUOTE_AND_FMT
#undef GET_ATOM_QUOTE_AND_FMT
return pc;
}
static JSBool
DecompileCode(JSPrinter *jp, JSScript *script, jsbytecode *pc, uintN len,
uintN pcdepth)
{
uintN depth, i;
SprintStack ss;
JSContext *cx;
void *mark;
JSBool ok;
JSScript *oldscript;
char *last;
depth = StackDepth(script);
JS_ASSERT(pcdepth <= depth);
cx = jp->sprinter.context;
AutoScriptUntrapper untrapper(cx, script, &pc);
/* Initialize a sprinter for use with the offset stack. */
mark = JS_ARENA_MARK(&cx->tempPool);
ok = InitSprintStack(cx, &ss, jp, depth);
if (!ok)
goto out;
/*
* If we are called from js_DecompileValueGenerator with a portion of
* script's bytecode that starts with a non-zero model stack depth given
* by pcdepth, attempt to initialize the missing string offsets in ss to
* |spindex| negative indexes from fp->sp for the activation fp in which
* the error arose.
*
* See js_DecompileValueGenerator for how its |spindex| parameter is used,
* and see also GetOff, which makes use of the ss.offsets[i] < -1 that are
* potentially stored below.
*/
ss.top = pcdepth;
if (pcdepth != 0) {
for (i = 0; i < pcdepth; i++) {
ss.offsets[i] = -2 - (ptrdiff_t)i;
ss.opcodes[i] = *jp->pcstack[i];
}
}
/* Call recursive subroutine to do the hard work. */
oldscript = jp->script;
jp->script = script;
ok = Decompile(&ss, pc, len, JSOP_NOP) != NULL;
jp->script = oldscript;
/* If the given code didn't empty the stack, do it now. */
if (ok && ss.top) {
do {
last = OFF2STR(&ss.sprinter, PopOff(&ss, JSOP_POP));
} while (ss.top > pcdepth);
js_printf(jp, "%s", last);
}
out:
/* Free all temporary stuff allocated under this call. */
JS_ARENA_RELEASE(&cx->tempPool, mark);
return ok;
}
/*
* Decompile a function body, expression closure expression, or complete
* script. Start at |pc|; go to the end of |script|. Include a directive
* prologue, if appropriate.
*/
static JSBool
DecompileBody(JSPrinter *jp, JSScript *script, jsbytecode *pc)
{
/* Print a strict mode code directive, if needed. */
if (script->strictModeCode && !jp->strict) {
if (jp->fun && (jp->fun->flags & JSFUN_EXPR_CLOSURE)) {
/*
* We have no syntax for strict function expressions;
* at least give a hint.
*/
js_printf(jp, "\t/* use strict */ \n");
} else {
js_printf(jp, "\t\"use strict\";\n");
}
jp->strict = true;
}
jsbytecode *end = script->code + script->length;
return DecompileCode(jp, script, pc, end - pc, 0);
}
JSBool
js_DecompileScript(JSPrinter *jp, JSScript *script)
{
return DecompileBody(jp, script, script->code);
}
JSString *
js_DecompileToString(JSContext *cx, const char *name, JSFunction *fun,
uintN indent, JSBool pretty, JSBool grouped, JSBool strict,
JSDecompilerPtr decompiler)
{
JSPrinter *jp;
JSString *str;
jp = js_NewPrinter(cx, name, fun, indent, pretty, grouped, strict);
if (!jp)
return NULL;
if (decompiler(jp))
str = js_GetPrinterOutput(jp);
else
str = NULL;
js_DestroyPrinter(jp);
return str;
}
static const char native_code_str[] = "\t[native code]\n";
JSBool
js_DecompileFunctionBody(JSPrinter *jp)
{
JSScript *script;
JS_ASSERT(jp->fun);
JS_ASSERT(!jp->script);
if (!jp->fun->isInterpreted()) {
js_printf(jp, native_code_str);
return JS_TRUE;
}
script = jp->fun->script();
return DecompileBody(jp, script, script->code);
}
JSBool
js_DecompileFunction(JSPrinter *jp)
{
JSFunction *fun;
uintN i;
JSAtom *param;
jsbytecode *pc, *endpc;
JSBool ok;
fun = jp->fun;
JS_ASSERT(fun);
JS_ASSERT(!jp->script);
/*
* If pretty, conform to ECMA-262 Edition 3, 15.3.4.2, by decompiling a
* FunctionDeclaration. Otherwise, check the JSFUN_LAMBDA flag and force
* an expression by parenthesizing.
*/
if (jp->pretty) {
js_printf(jp, "\t");
} else {
if (!jp->grouped && (fun->flags & JSFUN_LAMBDA))
js_puts(jp, "(");
}
js_printf(jp, "%s ", js_function_str);
if (fun->atom && !QuoteString(&jp->sprinter, fun->atom, 0))
return JS_FALSE;
js_puts(jp, "(");
if (!fun->isInterpreted()) {
js_printf(jp, ") {\n");
jp->indent += 4;
js_printf(jp, native_code_str);
jp->indent -= 4;
js_printf(jp, "\t}");
} else {
JSScript *script = fun->script();
#if JS_HAS_DESTRUCTURING
SprintStack ss;
void *mark;
#endif
/* Print the parameters. */
pc = script->main();
AutoScriptUntrapper untrapper(jp->sprinter.context, script, &pc);
endpc = pc + script->length;
ok = JS_TRUE;
#if JS_HAS_DESTRUCTURING
ss.printer = NULL;
jp->script = script;
mark = JS_ARENA_MARK(&jp->sprinter.context->tempPool);
#endif
for (i = 0; i < fun->nargs; i++) {
if (i > 0)
js_puts(jp, ", ");
param = GetArgOrVarAtom(jp, i);
#if JS_HAS_DESTRUCTURING
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_RV(expr, JS_FALSE)
if (!param) {
ptrdiff_t todo;
const char *lval;
LOCAL_ASSERT(*pc == JSOP_GETARG);
pc += JSOP_GETARG_LENGTH;
LOCAL_ASSERT(*pc == JSOP_DUP);
if (!ss.printer) {
ok = InitSprintStack(jp->sprinter.context, &ss, jp, StackDepth(script));
if (!ok)
break;
}
pc = DecompileDestructuring(&ss, pc, endpc);
if (!pc) {
ok = JS_FALSE;
break;
}
LOCAL_ASSERT(*pc == JSOP_POP);
pc += JSOP_POP_LENGTH;
lval = PopStr(&ss, JSOP_NOP);
todo = SprintCString(&jp->sprinter, lval);
if (todo < 0) {
ok = JS_FALSE;
break;
}
continue;
}
#undef LOCAL_ASSERT
#endif
if (!QuoteString(&jp->sprinter, param, 0)) {
ok = JS_FALSE;
break;
}
}
#if JS_HAS_DESTRUCTURING
jp->script = NULL;
JS_ARENA_RELEASE(&jp->sprinter.context->tempPool, mark);
#endif
if (!ok)
return JS_FALSE;
js_printf(jp, ") ");
if (!(fun->flags & JSFUN_EXPR_CLOSURE)) {
js_printf(jp, "{\n");
jp->indent += 4;
}
ok = DecompileBody(jp, script, pc);
if (!ok)
return JS_FALSE;
if (!(fun->flags & JSFUN_EXPR_CLOSURE)) {
jp->indent -= 4;
js_printf(jp, "\t}");
}
}
if (!jp->pretty && !jp->grouped && (fun->flags & JSFUN_LAMBDA))
js_puts(jp, ")");
return JS_TRUE;
}
char *
js_DecompileValueGenerator(JSContext *cx, intN spindex, jsval v_in,
JSString *fallback)
{
StackFrame *fp;
JSScript *script;
jsbytecode *pc;
Value v = Valueify(v_in);
JS_ASSERT(spindex < 0 ||
spindex == JSDVG_IGNORE_STACK ||
spindex == JSDVG_SEARCH_STACK);
LeaveTrace(cx);
if (!cx->hasfp() || !cx->fp()->isScriptFrame())
goto do_fallback;
fp = js_GetTopStackFrame(cx, FRAME_EXPAND_ALL);
script = fp->script();
pc = fp->hasImacropc() ? fp->imacropc() : cx->regs().pc;
JS_ASSERT(script->code <= pc && pc < script->code + script->length);
if (pc < script->main())
goto do_fallback;
if (spindex != JSDVG_IGNORE_STACK) {
jsbytecode **pcstack;
/*
* Prepare computing pcstack containing pointers to opcodes that
* populated interpreter's stack with its current content.
*/
pcstack = (jsbytecode **)
cx->malloc_(StackDepth(script) * sizeof *pcstack);
if (!pcstack)
return NULL;
intN pcdepth = ReconstructPCStack(cx, script, pc, pcstack);
if (pcdepth < 0)
goto release_pcstack;
if (spindex != JSDVG_SEARCH_STACK) {
JS_ASSERT(spindex < 0);
pcdepth += spindex;
if (pcdepth < 0)
goto release_pcstack;
pc = pcstack[pcdepth];
} else {
/*
* We search from fp->sp to base to find the most recently
* calculated value matching v under assumption that it is
* it that caused exception, see bug 328664.
*/
Value *stackBase = fp->base();
Value *sp = cx->regs().sp;
do {
if (sp == stackBase) {
pcdepth = -1;
goto release_pcstack;
}
} while (*--sp != v);
/*
* The value may have come from beyond stackBase + pcdepth, meaning
* that it came from a temporary slot pushed by the interpreter or
* arguments pushed for an Invoke call. Only update pc if beneath
* stackBase + pcdepth. If above, the value may or may not be
* produced by the current pc. Since it takes a fairly contrived
* combination of calls to produce a situation where this is not
* what we want, we just use the current pc.
*/
if (sp < stackBase + pcdepth)
pc = pcstack[sp - stackBase];
}
release_pcstack:
cx->free_(pcstack);
if (pcdepth < 0)
goto do_fallback;
}
{
jsbytecode* basepc = cx->regs().pc;
jsbytecode* savedImacropc = fp->maybeImacropc();
if (savedImacropc) {
cx->regs().pc = savedImacropc;
fp->clearImacropc();
}
/*
* FIXME: bug 489843. Stack reconstruction may have returned a pc
* value *inside* an imacro; this would confuse the decompiler.
*/
char *name;
if (savedImacropc && size_t(pc - script->code) >= script->length)
name = FAILED_EXPRESSION_DECOMPILER;
else
name = DecompileExpression(cx, script, fp->maybeFun(), pc);
if (savedImacropc) {
cx->regs().pc = basepc;
fp->setImacropc(savedImacropc);
}
if (name != FAILED_EXPRESSION_DECOMPILER)
return name;
}
do_fallback:
if (!fallback) {
fallback = js_ValueToSource(cx, v);
if (!fallback)
return NULL;
}
size_t length = fallback->length();
const jschar *chars = fallback->getChars(cx);
if (!chars)
return NULL;
return DeflateString(cx, chars, length);
}
static char *
DecompileExpression(JSContext *cx, JSScript *script, JSFunction *fun,
jsbytecode *pc)
{
JSOp op;
const JSCodeSpec *cs;
jsbytecode *begin, *end;
jssrcnote *sn;
ptrdiff_t len;
jsbytecode **pcstack;
intN pcdepth;
JSPrinter *jp;
char *name;
JS_ASSERT(script->code <= pc && pc < script->code + script->length);
pcstack = NULL;
AutoScriptUntrapper untrapper(cx, script, &pc);
op = (JSOp) *pc;
/* None of these stack-writing ops generates novel values. */
JS_ASSERT(op != JSOP_CASE && op != JSOP_CASEX &&
op != JSOP_DUP && op != JSOP_DUP2);
/* JSOP_PUSH is used to generate undefined for group assignment holes. */
if (op == JSOP_PUSH) {
name = JS_strdup(cx, js_undefined_str);
goto out;
}
/*
* |this| could convert to a very long object initialiser, so cite it by
* its keyword name instead.
*/
if (op == JSOP_THIS) {
name = JS_strdup(cx, js_this_str);
goto out;
}
/*
* JSOP_BINDNAME is special: it generates a value, the base object of a
* reference. But if it is the generating op for a diagnostic produced by
* js_DecompileValueGenerator, the name being bound is irrelevant. Just
* fall back to the base object.
*/
if (op == JSOP_BINDNAME) {
name = FAILED_EXPRESSION_DECOMPILER;
goto out;
}
/* NAME ops are self-contained, others require left or right context. */
cs = &js_CodeSpec[op];
begin = pc;
end = pc + cs->length;
switch (JOF_MODE(cs->format)) {
case JOF_PROP:
case JOF_ELEM:
case JOF_XMLNAME:
case 0:
sn = js_GetSrcNote(script, pc);
if (!sn) {
name = FAILED_EXPRESSION_DECOMPILER;
goto out;
}
switch (SN_TYPE(sn)) {
case SRC_PCBASE:
begin -= js_GetSrcNoteOffset(sn, 0);
break;
case SRC_PCDELTA:
end = begin + js_GetSrcNoteOffset(sn, 0);
begin += cs->length;
break;
default:
name = FAILED_EXPRESSION_DECOMPILER;
goto out;
}
break;
default:;
}
len = end - begin;
if (len <= 0) {
name = FAILED_EXPRESSION_DECOMPILER;
goto out;
}
pcstack = (jsbytecode **)
cx->malloc_(StackDepth(script) * sizeof *pcstack);
if (!pcstack) {
name = NULL;
goto out;
}
MUST_FLOW_THROUGH("out");
pcdepth = ReconstructPCStack(cx, script, begin, pcstack);
if (pcdepth < 0) {
name = FAILED_EXPRESSION_DECOMPILER;
goto out;
}
name = NULL;
jp = js_NewPrinter(cx, "js_DecompileValueGenerator", fun, 0,
false, false, false);
if (jp) {
jp->dvgfence = end;
jp->pcstack = pcstack;
if (DecompileCode(jp, script, begin, (uintN) len, (uintN) pcdepth)) {
name = (jp->sprinter.base) ? jp->sprinter.base : (char *) "";
name = JS_strdup(cx, name);
}
js_DestroyPrinter(jp);
}
out:
cx->free_(pcstack);
return name;
}
uintN
js_ReconstructStackDepth(JSContext *cx, JSScript *script, jsbytecode *pc)
{
return ReconstructPCStack(cx, script, pc, NULL);
}
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_RV(expr, -1);
static intN
SimulateOp(JSContext *cx, JSScript *script, JSOp op, const JSCodeSpec *cs,
jsbytecode *pc, jsbytecode **pcstack, uintN &pcdepth)
{
uintN nuses = js_GetStackUses(cs, op, pc);
uintN ndefs = js_GetStackDefs(cx, cs, op, script, pc);
LOCAL_ASSERT(pcdepth >= nuses);
pcdepth -= nuses;
LOCAL_ASSERT(pcdepth + ndefs <= StackDepth(script));
/*
* Fill the slots that the opcode defines withs its pc unless it just
* reshuffles the stack. In the latter case we want to preserve the
* opcode that generated the original value.
*/
switch (op) {
default:
if (pcstack) {
for (uintN i = 0; i != ndefs; ++i)
pcstack[pcdepth + i] = pc;
}
break;
case JSOP_CASE:
case JSOP_CASEX:
/* Keep the switch value. */
JS_ASSERT(ndefs == 1);
break;
case JSOP_DUP:
JS_ASSERT(ndefs == 2);
if (pcstack)
pcstack[pcdepth + 1] = pcstack[pcdepth];
break;
case JSOP_DUP2:
JS_ASSERT(ndefs == 4);
if (pcstack) {
pcstack[pcdepth + 2] = pcstack[pcdepth];
pcstack[pcdepth + 3] = pcstack[pcdepth + 1];
}
break;
case JSOP_SWAP:
JS_ASSERT(ndefs == 2);
if (pcstack) {
jsbytecode *tmp = pcstack[pcdepth + 1];
pcstack[pcdepth + 1] = pcstack[pcdepth];
pcstack[pcdepth] = tmp;
}
break;
}
pcdepth += ndefs;
return pcdepth;
}
#ifdef JS_TRACER
#undef LOCAL_ASSERT
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_CUSTOM(expr, goto failure);
static intN
SimulateImacroCFG(JSContext *cx, JSScript *script,
uintN pcdepth, jsbytecode *pc, jsbytecode *target,
jsbytecode **pcstack)
{
size_t nbytes = 0;
jsbytecode** tmp_pcstack = NULL;
if (pcstack) {
nbytes = StackDepth(script) * sizeof *pcstack;
tmp_pcstack = (jsbytecode **) cx->malloc_(nbytes);
if (!tmp_pcstack)
return -1;
memcpy(tmp_pcstack, pcstack, nbytes);
}
ptrdiff_t oplen;
for (; pc < target; pc += oplen) {
JSOp op = js_GetOpcode(cx, script, pc);
const JSCodeSpec *cs = &js_CodeSpec[op];
oplen = cs->length;
if (oplen < 0)
oplen = js_GetVariableBytecodeLength(pc);
if (SimulateOp(cx, script, op, cs, pc, tmp_pcstack, pcdepth) < 0)
goto failure;
uint32 type = cs->format & JOF_TYPEMASK;
if (type == JOF_JUMP || type == JOF_JUMPX) {
ptrdiff_t jmpoff = (type == JOF_JUMP) ? GET_JUMP_OFFSET(pc)
: GET_JUMPX_OFFSET(pc);
LOCAL_ASSERT(jmpoff >= 0);
intN tmp_pcdepth = SimulateImacroCFG(cx, script, pcdepth, pc + jmpoff,
target, tmp_pcstack);
if (tmp_pcdepth >= 0) {
pcdepth = uintN(tmp_pcdepth);
goto success;
}
if (op == JSOP_GOTO || op == JSOP_GOTOX)
goto failure;
}
}
if (pc > target)
goto failure;
LOCAL_ASSERT(pc == target);
success:
if (tmp_pcstack) {
memcpy(pcstack, tmp_pcstack, nbytes);
cx->free_(tmp_pcstack);
}
return pcdepth;
failure:
if (tmp_pcstack)
cx->free_(tmp_pcstack);
return -1;
}
#undef LOCAL_ASSERT
#define LOCAL_ASSERT(expr) LOCAL_ASSERT_RV(expr, -1);
static intN
ReconstructImacroPCStack(JSContext *cx, JSScript *script,
jsbytecode *imacstart, jsbytecode *target,
jsbytecode **pcstack)
{
/*
* Begin with a recursive call back to ReconstructPCStack to pick up
* the state-of-the-world at the *start* of the imacro.
*/
StackFrame *fp = js_GetScriptedCaller(cx, NULL);
JS_ASSERT(fp->hasImacropc());
intN pcdepth = ReconstructPCStack(cx, script, fp->imacropc(), pcstack);
if (pcdepth < 0)
return pcdepth;
return SimulateImacroCFG(cx, script, pcdepth, imacstart, target, pcstack);
}
extern jsbytecode* js_GetImacroStart(jsbytecode* pc);
#endif
static intN
ReconstructPCStack(JSContext *cx, JSScript *script, jsbytecode *target,
jsbytecode **pcstack)
{
/*
* Walk forward from script->main and compute the stack depth and stack of
* operand-generating opcode PCs in pcstack.
*
* FIXME: Code to compute oplen copied from js_Disassemble1 and reduced.
* FIXME: Optimize to use last empty-stack sequence point.
*/
#ifdef JS_TRACER
jsbytecode *imacstart = js_GetImacroStart(target);
if (imacstart)
return ReconstructImacroPCStack(cx, script, imacstart, target, pcstack);
#endif
LOCAL_ASSERT(script->code <= target && target < script->code + script->length);
jsbytecode *pc = script->code;
uintN pcdepth = 0;
ptrdiff_t oplen;
for (; pc < target; pc += oplen) {
JSOp op = js_GetOpcode(cx, script, pc);
const JSCodeSpec *cs = &js_CodeSpec[op];
oplen = cs->length;
if (oplen < 0)
oplen = js_GetVariableBytecodeLength(pc);
if (cs->format & JOF_DECOMPOSE)
continue;
/*
* A (C ? T : E) expression requires skipping either T (if target is in
* E) or both T and E (if target is after the whole expression) before
* adjusting pcdepth based on the JSOP_IFEQ or JSOP_IFEQX at pc that
* tests condition C. We know that the stack depth can't change from
* what it was with C on top of stack.
*/
jssrcnote *sn = js_GetSrcNote(script, pc);
if (sn && SN_TYPE(sn) == SRC_COND) {
ptrdiff_t jmpoff = js_GetSrcNoteOffset(sn, 0);
if (pc + jmpoff < target) {
pc += jmpoff;
op = js_GetOpcode(cx, script, pc);
JS_ASSERT(op == JSOP_GOTO || op == JSOP_GOTOX);
cs = &js_CodeSpec[op];
oplen = cs->length;
JS_ASSERT(oplen > 0);
ptrdiff_t jmplen = GetJumpOffset(pc, pc);
if (pc + jmplen < target) {
oplen = (uintN) jmplen;
continue;
}
/*
* Ok, target lies in E. Manually pop C off the model stack,
* since we have moved beyond the IFEQ now.
*/
LOCAL_ASSERT(pcdepth != 0);
--pcdepth;
}
}
/* Ignore early-exit code, which is annotated SRC_HIDDEN. */
if (sn && SN_TYPE(sn) == SRC_HIDDEN)
continue;
if (SimulateOp(cx, script, op, cs, pc, pcstack, pcdepth) < 0)
return -1;
}
LOCAL_ASSERT(pc == target);
return pcdepth;
}
#undef LOCAL_ASSERT
#undef LOCAL_ASSERT_RV
namespace js {
bool
CallResultEscapes(jsbytecode *pc)
{
/*
* If we see any of these sequences, the result is unused:
* - call / pop
* - call / trace / pop
*
* If we see any of these sequences, the result is only tested for nullness:
* - call / ifeq
* - call / trace / ifeq
* - call / not / ifeq
* - call / trace / not / ifeq
*/
if (*pc != JSOP_CALL)
return true;
pc += JSOP_CALL_LENGTH;
if (*pc == JSOP_TRACE)
pc += JSOP_TRACE_LENGTH;
if (*pc == JSOP_POP)
return false;
if (*pc == JSOP_NOT)
pc += JSOP_NOT_LENGTH;
return (*pc != JSOP_IFEQ);
}
size_t
GetBytecodeLength(JSContext *cx, JSScript *script, jsbytecode *pc)
{
JSOp op = js_GetOpcode(cx, script, pc);
JS_ASSERT(op < JSOP_LIMIT);
JS_ASSERT(op != JSOP_TRAP);
if (js_CodeSpec[op].length != -1)
return js_CodeSpec[op].length;
return js_GetVariableBytecodeLength(op, pc);
}
extern bool
IsValidBytecodeOffset(JSContext *cx, JSScript *script, size_t offset)
{
// This could be faster (by following jump instructions if the target is <= offset).
for (BytecodeRange r(cx, script); !r.empty(); r.popFront()) {
size_t here = r.frontOffset();
if (here >= offset)
return here == offset;
}
return false;
}
} // namespace js
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