The Tor Browser: js/src/jit/Snapshots.cpp@129ffea94266 (annotated)

js/src/jit/Snapshots.cpp@129ffea94266 (annotated)

js/src/jit/Snapshots.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "jit/Snapshots.h"
 #include "jsscript.h"
 #include "jit/CompileInfo.h"
 #include "jit/IonSpewer.h"
 #ifdef TRACK_SNAPSHOTS
 # include "jit/LIR.h"
 #endif
 #include "jit/MIR.h"
 #include "jit/Recover.h"
 using namespace js;
 using namespace js::jit;
 // Snapshot header:
 //
 //   [vwu] bits ((n+1)-31]: frame count
 //         bit n+1: resume after
 //         bits [0,n): bailout kind (n = SNAPSHOT_BAILOUTKIND_BITS)
 //
 // Snapshot body, repeated "frame count" times, from oldest frame to newest frame.
 // Note that the first frame doesn't have the "parent PC" field.
 //
 //   [ptr] Debug only: JSScript *
 //   [vwu] pc offset
 //   [vwu] # of RVA's indexes, including nargs
 //  [vwu*] List of indexes to R(ecover)ValueAllocation table. Contains
 //         nargs + nfixed + stackDepth items.
 //
 // Recover value allocations are encoded at the end of the Snapshot buffer, and
 // they are padded on ALLOCATION_TABLE_ALIGNMENT.  The encoding of each
 // allocation is determined by the RValueAllocation::Layout, which can be
 // obtained from the RValueAllocation::Mode with layoutFromMode function.  The
 // layout structure list the type of payload which are used to serialized /
 // deserialized / dumped the content of the allocations.
 //
 // R(ecover)ValueAllocation items:
 //   [u8'] Mode, which defines the type of the payload as well as the
 //         interpretation.
 //   [pld] first payload (packed tag, index, stack offset, register, ...)
 //   [pld] second payload (register, stack offset, none)
 //
 //       Modes:
 //         CONSTANT [INDEX]
 //           Index into the constant pool.
 //
 //         CST_UNDEFINED []
 //           Constant value which correspond to the "undefined" JS value.
 //
 //         CST_NULL []
 //           Constant value which correspond to the "null" JS value.
 //
 //         DOUBLE_REG [FPU_REG]
 //           Double value stored in a FPU register.
 //
 //         FLOAT32_REG [FPU_REG]
 //           Float 32bit value stored in a FPU register.
 //
 //         FLOAT32_STACK [STACK_OFFSET]
 //           Float 32bit value stored on the stack.
 //
 //         UNTYPED_REG   [GPR_REG]
 //         UNTYPED_STACK [STACK_OFFSET]
 //         UNTYPED_REG_REG     [GPR_REG,      GPR_REG]
 //         UNTYPED_REG_STACK   [GPR_REG,      STACK_OFFSET]
 //         UNTYPED_STACK_REG   [STACK_OFFSET, GPR_REG]
 //         UNTYPED_STACK_STACK [STACK_OFFSET, STACK_OFFSET]
 //           Value with dynamically known type. On 32 bits architecture, the
 //           first register/stack-offset correspond to the holder of the type,
 //           and the second correspond to the payload of the JS Value.
 //
 //         TYPED_REG [PACKED_TAG, GPR_REG]:
 //           Value with statically known type, which payload is stored in a
 //           register.
 //
 //         TYPED_STACK [PACKED_TAG, STACK_OFFSET]:
 //           Value with statically known type, which payload is stored at an
 //           offset on the stack.
 //
 // Encodings:
 //   [ptr] A fixed-size pointer.
 //   [vwu] A variable-width unsigned integer.
 //   [vws] A variable-width signed integer.
 //    [u8] An 8-bit unsigned integer.
 //   [u8'] An 8-bit unsigned integer which is potentially extended with packed
 //         data.
 //   [u8"] Packed data which is stored and packed in the previous [u8'].
 //  [vwu*] A list of variable-width unsigned integers.
 //   [pld] Payload of Recover Value Allocation:
 //         PAYLOAD_NONE:
 //           There is no payload.
 //
 //         PAYLOAD_INDEX:
 //           [vwu] Index, such as the constant pool index.
 //
 //         PAYLOAD_STACK_OFFSET:
 //           [vws] Stack offset based on the base of the Ion frame.
 //
 //         PAYLOAD_GPR:
 //            [u8] Code of the general register.
 //
 //         PAYLOAD_FPU:
 //            [u8] Code of the FPU register.
 //
 //         PAYLOAD_PACKED_TAG:
 //           [u8"] Bits 5-7: JSValueType is encoded on the low bits of the Mode
 //                           of the RValueAllocation.
 //
 const RValueAllocation::Layout &
 RValueAllocation::layoutFromMode(Mode mode)
 {
     switch (mode) {
       case CONSTANT: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_INDEX,
             PAYLOAD_NONE,
             "constant"
         };
         return layout;
       }
       case CST_UNDEFINED: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_NONE,
             PAYLOAD_NONE,
             "undefined"
         };
         return layout;
       }
       case CST_NULL: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_NONE,
             PAYLOAD_NONE,
             "null"
         };
         return layout;
       }
       case DOUBLE_REG: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_FPU,
             PAYLOAD_NONE,
             "double"
         };
         return layout;
       }
       case FLOAT32_REG: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_FPU,
             PAYLOAD_NONE,
             "float32"
         };
         return layout;
       }
       case FLOAT32_STACK: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_STACK_OFFSET,
             PAYLOAD_NONE,
             "float32"
         };
         return layout;
       }
 #if defined(JS_NUNBOX32)
       case UNTYPED_REG_REG: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_GPR,
             PAYLOAD_GPR,
             "value"
         };
         return layout;
       }
       case UNTYPED_REG_STACK: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_GPR,
             PAYLOAD_STACK_OFFSET,
             "value"
         };
         return layout;
       }
       case UNTYPED_STACK_REG: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_STACK_OFFSET,
             PAYLOAD_GPR
         };
         return layout;
       }
       case UNTYPED_STACK_STACK: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_STACK_OFFSET,
             PAYLOAD_STACK_OFFSET,
             "value"
         };
         return layout;
       }
 #elif defined(JS_PUNBOX64)
       case UNTYPED_REG: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_GPR,
             PAYLOAD_NONE,
             "value"
         };
         return layout;
       }
       case UNTYPED_STACK: {
         static const RValueAllocation::Layout layout = {
             PAYLOAD_STACK_OFFSET,
             PAYLOAD_NONE,
             "value"
         };
         return layout;
       }
 #endif
       default: {
         static const RValueAllocation::Layout regLayout = {
             PAYLOAD_PACKED_TAG,
             PAYLOAD_GPR,
             "typed value"
         };
         static const RValueAllocation::Layout stackLayout = {
             PAYLOAD_PACKED_TAG,
             PAYLOAD_STACK_OFFSET,
             "typed value"
         };
         if (mode >= TYPED_REG_MIN && mode <= TYPED_REG_MAX)
             return regLayout;
         if (mode >= TYPED_STACK_MIN && mode <= TYPED_STACK_MAX)
             return stackLayout;
       }
     }
     MOZ_ASSUME_UNREACHABLE("Wrong mode type?");
 }
 // Pad serialized RValueAllocations by a multiple of X bytes in the allocation
 // buffer.  By padding serialized value allocations, we are building an
 // indexable table of elements of X bytes, and thus we can safely divide any
 // offset within the buffer by X to obtain an index.
 //
 // By padding, we are loosing space within the allocation buffer, but we
 // multiple by X the number of indexes that we can store on one byte in each
 // snapshots.
 //
 // Some value allocations are taking more than X bytes to be encoded, in which
 // case we will pad to a multiple of X, and we are wasting indexes. The choice
 // of X should be balanced between the wasted padding of serialized value
 // allocation, and the saving made in snapshot indexes.
 static const size_t ALLOCATION_TABLE_ALIGNMENT = 2; /* bytes */
 void
 RValueAllocation::readPayload(CompactBufferReader &reader, PayloadType type,
                               uint8_t *mode, Payload *p)
 {
     switch (type) {
       case PAYLOAD_NONE:
         break;
       case PAYLOAD_INDEX:
         p->index = reader.readUnsigned();
         break;
       case PAYLOAD_STACK_OFFSET:
         p->stackOffset = reader.readSigned();
         break;
       case PAYLOAD_GPR:
         p->gpr = Register::FromCode(reader.readByte());
         break;
       case PAYLOAD_FPU:
         p->fpu = FloatRegister::FromCode(reader.readByte());
         break;
       case PAYLOAD_PACKED_TAG:
         p->type = JSValueType(*mode & 0x07);
         *mode = *mode & ~0x07;
         break;
     }
 }
 RValueAllocation
 RValueAllocation::read(CompactBufferReader &reader)
 {
     uint8_t mode = reader.readByte();
     const Layout &layout = layoutFromMode(Mode(mode));
     Payload arg1, arg2;
     readPayload(reader, layout.type1, &mode, &arg1);
     readPayload(reader, layout.type2, &mode, &arg2);
     return RValueAllocation(Mode(mode), arg1, arg2);
 }
 void
 RValueAllocation::writePayload(CompactBufferWriter &writer, PayloadType type,
                                Payload p)
 {
     switch (type) {
       case PAYLOAD_NONE:
         break;
       case PAYLOAD_INDEX:
         writer.writeUnsigned(p.index);
         break;
       case PAYLOAD_STACK_OFFSET:
         writer.writeSigned(p.stackOffset);
         break;
       case PAYLOAD_GPR:
         static_assert(Registers::Total <= 0x100,
                       "Not enough bytes to encode all registers.");
         writer.writeByte(p.gpr.code());
         break;
       case PAYLOAD_FPU:
         static_assert(FloatRegisters::Total <= 0x100,
                       "Not enough bytes to encode all float registers.");
         writer.writeByte(p.fpu.code());
         break;
       case PAYLOAD_PACKED_TAG: {
         // This code assumes that the PACKED_TAG payload is following the
         // writeByte of the mode.
         MOZ_ASSERT(writer.length());
         uint8_t *mode = writer.buffer() + (writer.length() - 1);
         MOZ_ASSERT((*mode & 0x07) == 0 && (p.type & ~0x07) == 0);
         *mode = *mode | p.type;
         break;
       }
     }
 }
 void
 RValueAllocation::writePadding(CompactBufferWriter &writer)
 {
     // Write 0x7f in all padding bytes.
     while (writer.length() % ALLOCATION_TABLE_ALIGNMENT)
         writer.writeByte(0x7f);
 }
 void
 RValueAllocation::write(CompactBufferWriter &writer) const
 {
     const Layout &layout = layoutFromMode(mode());
     MOZ_ASSERT(layout.type2 != PAYLOAD_PACKED_TAG);
     MOZ_ASSERT(writer.length() % ALLOCATION_TABLE_ALIGNMENT == 0);
     writer.writeByte(mode_);
     writePayload(writer, layout.type1, arg1_);
     writePayload(writer, layout.type2, arg2_);
     writePadding(writer);
 }
 HashNumber
 RValueAllocation::hash() const {
     CompactBufferWriter writer;
     write(writer);
     // We should never oom because the compact buffer writer has 32 inlined
     // bytes, and in the worse case scenario, only encode 12 bytes
     // (12 == mode + signed + signed + pad).
     MOZ_ASSERT(!writer.oom());
     MOZ_ASSERT(writer.length() <= 12);
     HashNumber res = 0;
     for (size_t i = 0; i < writer.length(); i++) {
         res = ((res << 8) | (res >> (sizeof(res) - 1)));
         res ^= writer.buffer()[i];
     }
     return res;
 }
 static const char *
 ValTypeToString(JSValueType type)
 {
     switch (type) {
       case JSVAL_TYPE_INT32:
         return "int32_t";
       case JSVAL_TYPE_DOUBLE:
         return "double";
       case JSVAL_TYPE_STRING:
         return "string";
       case JSVAL_TYPE_BOOLEAN:
         return "boolean";
       case JSVAL_TYPE_OBJECT:
         return "object";
       case JSVAL_TYPE_MAGIC:
         return "magic";
       default:
         MOZ_ASSUME_UNREACHABLE("no payload");
     }
 }
 void
 RValueAllocation::dumpPayload(FILE *fp, PayloadType type, Payload p)
 {
     switch (type) {
       case PAYLOAD_NONE:
         break;
       case PAYLOAD_INDEX:
         fprintf(fp, "index %u", p.index);
         break;
       case PAYLOAD_STACK_OFFSET:
         fprintf(fp, "stack %d", p.stackOffset);
         break;
       case PAYLOAD_GPR:
         fprintf(fp, "reg %s", p.gpr.name());
         break;
       case PAYLOAD_FPU:
         fprintf(fp, "reg %s", p.fpu.name());
         break;
       case PAYLOAD_PACKED_TAG:
         fprintf(fp, "%s", ValTypeToString(p.type));
         break;
     }
 }
 void
 RValueAllocation::dump(FILE *fp) const
 {
     const Layout &layout = layoutFromMode(mode());
     fprintf(fp, "%s", layout.name);
     if (layout.type1 != PAYLOAD_NONE)
         fprintf(fp, " (");
     dumpPayload(fp, layout.type1, arg1_);
     if (layout.type2 != PAYLOAD_NONE)
         fprintf(fp, ", ");
     dumpPayload(fp, layout.type2, arg2_);
     if (layout.type1 != PAYLOAD_NONE)
         fprintf(fp, ")");
 }
 bool
 RValueAllocation::equalPayloads(PayloadType type, Payload lhs, Payload rhs)
 {
     switch (type) {
       case PAYLOAD_NONE:
         return true;
       case PAYLOAD_INDEX:
         return lhs.index == rhs.index;
       case PAYLOAD_STACK_OFFSET:
         return lhs.stackOffset == rhs.stackOffset;
       case PAYLOAD_GPR:
         return lhs.gpr == rhs.gpr;
       case PAYLOAD_FPU:
         return lhs.fpu == rhs.fpu;
       case PAYLOAD_PACKED_TAG:
         return lhs.type == rhs.type;
     }
     return false;
 }
 SnapshotReader::SnapshotReader(const uint8_t *snapshots, uint32_t offset,
                                uint32_t RVATableSize, uint32_t listSize)
   : reader_(snapshots + offset, snapshots + listSize),
     allocReader_(snapshots + listSize, snapshots + listSize + RVATableSize),
     allocTable_(snapshots + listSize),
     allocRead_(0)
 {
     if (!snapshots)
         return;
     IonSpew(IonSpew_Snapshots, "Creating snapshot reader");
     readSnapshotHeader();
 }
 #define COMPUTE_SHIFT_AFTER_(name) (name ## _BITS + name ##_SHIFT)
 #define COMPUTE_MASK_(name) ((uint32_t(1 << name ## _BITS) - 1) << name ##_SHIFT)
 // Details of snapshot header packing.
 static const uint32_t SNAPSHOT_BAILOUTKIND_SHIFT = 0;
 static const uint32_t SNAPSHOT_BAILOUTKIND_BITS = 3;
 static const uint32_t SNAPSHOT_BAILOUTKIND_MASK = COMPUTE_MASK_(SNAPSHOT_BAILOUTKIND);
 static const uint32_t SNAPSHOT_ROFFSET_SHIFT = COMPUTE_SHIFT_AFTER_(SNAPSHOT_BAILOUTKIND);
 static const uint32_t SNAPSHOT_ROFFSET_BITS = 32 - SNAPSHOT_ROFFSET_SHIFT;
 static const uint32_t SNAPSHOT_ROFFSET_MASK = COMPUTE_MASK_(SNAPSHOT_ROFFSET);
 // Details of recover header packing.
 static const uint32_t RECOVER_RESUMEAFTER_SHIFT = 0;
 static const uint32_t RECOVER_RESUMEAFTER_BITS = 1;
 static const uint32_t RECOVER_RESUMEAFTER_MASK = COMPUTE_MASK_(RECOVER_RESUMEAFTER);
 static const uint32_t RECOVER_RINSCOUNT_SHIFT = COMPUTE_SHIFT_AFTER_(RECOVER_RESUMEAFTER);
 static const uint32_t RECOVER_RINSCOUNT_BITS = 32 - RECOVER_RINSCOUNT_SHIFT;
 static const uint32_t RECOVER_RINSCOUNT_MASK = COMPUTE_MASK_(RECOVER_RINSCOUNT);
 #undef COMPUTE_MASK_
 #undef COMPUTE_SHIFT_AFTER_
 void
 SnapshotReader::readSnapshotHeader()
 {
     uint32_t bits = reader_.readUnsigned();
     bailoutKind_ = BailoutKind((bits & SNAPSHOT_BAILOUTKIND_MASK) >> SNAPSHOT_BAILOUTKIND_SHIFT);
     recoverOffset_ = (bits & SNAPSHOT_ROFFSET_MASK) >> SNAPSHOT_ROFFSET_SHIFT;
     IonSpew(IonSpew_Snapshots, "Read snapshot header with bailout kind %u",
             bailoutKind_);
 #ifdef TRACK_SNAPSHOTS
     readTrackSnapshot();
 #endif
 }
 #ifdef TRACK_SNAPSHOTS
 void
 SnapshotReader::readTrackSnapshot()
 {
     pcOpcode_  = reader_.readUnsigned();
     mirOpcode_ = reader_.readUnsigned();
     mirId_     = reader_.readUnsigned();
     lirOpcode_ = reader_.readUnsigned();
     lirId_     = reader_.readUnsigned();
 }
 void
 SnapshotReader::spewBailingFrom() const
 {
     if (IonSpewEnabled(IonSpew_Bailouts)) {
         IonSpewHeader(IonSpew_Bailouts);
         fprintf(IonSpewFile, " bailing from bytecode: %s, MIR: ", js_CodeName[pcOpcode_]);
         MDefinition::PrintOpcodeName(IonSpewFile, MDefinition::Opcode(mirOpcode_));
         fprintf(IonSpewFile, " [%u], LIR: ", mirId_);
         LInstruction::printName(IonSpewFile, LInstruction::Opcode(lirOpcode_));
         fprintf(IonSpewFile, " [%u]", lirId_);
         fprintf(IonSpewFile, "\n");
     }
 }
 #endif
 uint32_t
 SnapshotReader::readAllocationIndex()
 {
     allocRead_++;
     return reader_.readUnsigned();
 }
 RValueAllocation
 SnapshotReader::readAllocation()
 {
     IonSpew(IonSpew_Snapshots, "Reading slot %u", allocRead_);
     uint32_t offset = readAllocationIndex() * ALLOCATION_TABLE_ALIGNMENT;
     allocReader_.seek(allocTable_, offset);
     return RValueAllocation::read(allocReader_);
 }
 bool
 SnapshotWriter::init()
 {
     // Based on the measurements made in Bug 962555 comment 20, this should be
     // enough to prevent the reallocation of the hash table for at least half of
     // the compilations.
     return allocMap_.init(32);
 }
 RecoverReader::RecoverReader(SnapshotReader &snapshot, const uint8_t *recovers, uint32_t size)
   : reader_(nullptr, nullptr),
     numInstructions_(0),
     numInstructionsRead_(0)
 {
     if (!recovers)
         return;
     reader_ = CompactBufferReader(recovers + snapshot.recoverOffset(), recovers + size);
     readRecoverHeader();
     readInstruction();
 }
 void
 RecoverReader::readRecoverHeader()
 {
     uint32_t bits = reader_.readUnsigned();
     numInstructions_ = (bits & RECOVER_RINSCOUNT_MASK) >> RECOVER_RINSCOUNT_SHIFT;
     resumeAfter_ = (bits & RECOVER_RESUMEAFTER_MASK) >> RECOVER_RESUMEAFTER_SHIFT;
     MOZ_ASSERT(numInstructions_);
     IonSpew(IonSpew_Snapshots, "Read recover header with instructionCount %u (ra: %d)",
             numInstructions_, resumeAfter_);
 }
 void
 RecoverReader::readInstruction()
 {
     MOZ_ASSERT(moreInstructions());
     RInstruction::readRecoverData(reader_, &rawData_);
     numInstructionsRead_++;
 }
 SnapshotOffset
 SnapshotWriter::startSnapshot(RecoverOffset recoverOffset, BailoutKind kind)
 {
     lastStart_ = writer_.length();
     allocWritten_ = 0;
     IonSpew(IonSpew_Snapshots, "starting snapshot with recover offset %u, bailout kind %u",
             recoverOffset, kind);
     JS_ASSERT(uint32_t(kind) < (1 << SNAPSHOT_BAILOUTKIND_BITS));
     JS_ASSERT(recoverOffset < (1 << SNAPSHOT_ROFFSET_BITS));
     uint32_t bits =
         (uint32_t(kind) << SNAPSHOT_BAILOUTKIND_SHIFT) |
         (recoverOffset << SNAPSHOT_ROFFSET_SHIFT);
     writer_.writeUnsigned(bits);
     return lastStart_;
 }
 #ifdef TRACK_SNAPSHOTS
 void
 SnapshotWriter::trackSnapshot(uint32_t pcOpcode, uint32_t mirOpcode, uint32_t mirId,
                               uint32_t lirOpcode, uint32_t lirId)
 {
     writer_.writeUnsigned(pcOpcode);
     writer_.writeUnsigned(mirOpcode);
     writer_.writeUnsigned(mirId);
     writer_.writeUnsigned(lirOpcode);
     writer_.writeUnsigned(lirId);
 }
 #endif
 bool
 SnapshotWriter::add(const RValueAllocation &alloc)
 {
     MOZ_ASSERT(allocMap_.initialized());
     uint32_t offset;
     RValueAllocMap::AddPtr p = allocMap_.lookupForAdd(alloc);
     if (!p) {
         offset = allocWriter_.length();
         alloc.write(allocWriter_);
         if (!allocMap_.add(p, alloc, offset))
             return false;
     } else {
         offset = p->value();
     }
     if (IonSpewEnabled(IonSpew_Snapshots)) {
         IonSpewHeader(IonSpew_Snapshots);
         fprintf(IonSpewFile, "    slot %u (%d): ", allocWritten_, offset);
         alloc.dump(IonSpewFile);
         fprintf(IonSpewFile, "\n");
     }
     allocWritten_++;
     writer_.writeUnsigned(offset / ALLOCATION_TABLE_ALIGNMENT);
     return true;
 }
 void
 SnapshotWriter::endSnapshot()
 {
     // Place a sentinel for asserting on the other end.
 #ifdef DEBUG
     writer_.writeSigned(-1);
 #endif
     IonSpew(IonSpew_Snapshots, "ending snapshot total size: %u bytes (start %u)",
             uint32_t(writer_.length() - lastStart_), lastStart_);
 }
 RecoverOffset
 RecoverWriter::startRecover(uint32_t frameCount, bool resumeAfter)
 {
     MOZ_ASSERT(frameCount);
     nframes_ = frameCount;
     framesWritten_ = 0;
     IonSpew(IonSpew_Snapshots, "starting recover with frameCount %u",
             frameCount);
     MOZ_ASSERT(!(uint32_t(resumeAfter) &~ RECOVER_RESUMEAFTER_MASK));
     MOZ_ASSERT(frameCount < uint32_t(1 << RECOVER_RINSCOUNT_BITS));
     uint32_t bits =
         (uint32_t(resumeAfter) << RECOVER_RESUMEAFTER_SHIFT) |
         (frameCount << RECOVER_RINSCOUNT_SHIFT);
     RecoverOffset recoverOffset = writer_.length();
     writer_.writeUnsigned(bits);
     return recoverOffset;
 }
 bool
 RecoverWriter::writeFrame(const MResumePoint *rp)
 {
     if (!rp->writeRecoverData(writer_))
         return false;
     framesWritten_++;
     return true;
 }
 void
 RecoverWriter::endRecover()
 {
     JS_ASSERT(nframes_ == framesWritten_);
 }

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js/src/jit/Snapshots.cpp@129ffea94266 (annotated)

js/src/jit/Snapshots.cpp