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Diffstat (limited to 'js/src/jit/JitcodeMap.cpp')
| -rw-r--r-- | js/src/jit/JitcodeMap.cpp | 1145 |
1 files changed, 1145 insertions, 0 deletions
diff --git a/js/src/jit/JitcodeMap.cpp b/js/src/jit/JitcodeMap.cpp new file mode 100644 index 0000000000..1c1e21c72e --- /dev/null +++ b/js/src/jit/JitcodeMap.cpp @@ -0,0 +1,1145 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * 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/JitcodeMap.h" + +#include "mozilla/ArrayUtils.h" +#include "mozilla/MathAlgorithms.h" +#include "mozilla/Maybe.h" +#include "mozilla/ScopeExit.h" + +#include "gc/Marking.h" +#include "jit/BaselineJIT.h" +#include "jit/InlineScriptTree.h" +#include "jit/JitRuntime.h" +#include "jit/JitSpewer.h" +#include "js/Vector.h" +#include "vm/BytecodeLocation.h" // for BytecodeLocation +#include "vm/GeckoProfiler.h" + +#include "vm/GeckoProfiler-inl.h" +#include "vm/JSScript-inl.h" + +using mozilla::Maybe; + +namespace js { +namespace jit { + +static inline JitcodeRegionEntry RegionAtAddr(const IonEntry& entry, void* ptr, + uint32_t* ptrOffset) { + MOZ_ASSERT(entry.containsPointer(ptr)); + *ptrOffset = reinterpret_cast<uint8_t*>(ptr) - + reinterpret_cast<uint8_t*>(entry.nativeStartAddr()); + + uint32_t regionIdx = entry.regionTable()->findRegionEntry(*ptrOffset); + MOZ_ASSERT(regionIdx < entry.regionTable()->numRegions()); + + return entry.regionTable()->regionEntry(regionIdx); +} + +void* IonEntry::canonicalNativeAddrFor(void* ptr) const { + uint32_t ptrOffset; + JitcodeRegionEntry region = RegionAtAddr(*this, ptr, &ptrOffset); + return (void*)(((uint8_t*)nativeStartAddr()) + region.nativeOffset()); +} + +bool IonEntry::callStackAtAddr(void* ptr, BytecodeLocationVector& results, + uint32_t* depth) const { + uint32_t ptrOffset; + JitcodeRegionEntry region = RegionAtAddr(*this, ptr, &ptrOffset); + *depth = region.scriptDepth(); + + JitcodeRegionEntry::ScriptPcIterator locationIter = region.scriptPcIterator(); + MOZ_ASSERT(locationIter.hasMore()); + bool first = true; + while (locationIter.hasMore()) { + uint32_t scriptIdx, pcOffset; + locationIter.readNext(&scriptIdx, &pcOffset); + // For the first entry pushed (innermost frame), the pcOffset is obtained + // from the delta-run encodings. + if (first) { + pcOffset = region.findPcOffset(ptrOffset, pcOffset); + first = false; + } + JSScript* script = getScript(scriptIdx); + jsbytecode* pc = script->offsetToPC(pcOffset); + if (!results.append(BytecodeLocation(script, pc))) { + return false; + } + } + + return true; +} + +uint32_t IonEntry::callStackAtAddr(void* ptr, const char** results, + uint32_t maxResults) const { + MOZ_ASSERT(maxResults >= 1); + + uint32_t ptrOffset; + JitcodeRegionEntry region = RegionAtAddr(*this, ptr, &ptrOffset); + + JitcodeRegionEntry::ScriptPcIterator locationIter = region.scriptPcIterator(); + MOZ_ASSERT(locationIter.hasMore()); + uint32_t count = 0; + while (locationIter.hasMore()) { + uint32_t scriptIdx, pcOffset; + + locationIter.readNext(&scriptIdx, &pcOffset); + MOZ_ASSERT(getStr(scriptIdx)); + + results[count++] = getStr(scriptIdx); + if (count >= maxResults) { + break; + } + } + + return count; +} + +uint64_t IonEntry::lookupRealmID(void* ptr) const { + uint32_t ptrOffset; + JitcodeRegionEntry region = RegionAtAddr(*this, ptr, &ptrOffset); + JitcodeRegionEntry::ScriptPcIterator locationIter = region.scriptPcIterator(); + MOZ_ASSERT(locationIter.hasMore()); + uint32_t scriptIdx, pcOffset; + locationIter.readNext(&scriptIdx, &pcOffset); + + JSScript* script = getScript(scriptIdx); + return script->realm()->creationOptions().profilerRealmID(); +} + +IonEntry::~IonEntry() { + // The region table is stored at the tail of the compacted data, + // which means the start of the region table is a pointer to + // the _middle_ of the memory space allocated for it. + // + // When freeing it, obtain the payload start pointer first. + MOZ_ASSERT(regionTable_); + js_free((void*)(regionTable_->payloadStart())); + regionTable_ = nullptr; +} + +static IonEntry& IonEntryForIonIC(JSRuntime* rt, const IonICEntry* icEntry) { + // The table must have an IonEntry for the IC's rejoin address. + auto* table = rt->jitRuntime()->getJitcodeGlobalTable(); + auto* entry = table->lookup(icEntry->rejoinAddr()); + MOZ_ASSERT(entry); + MOZ_RELEASE_ASSERT(entry->isIon()); + return entry->asIon(); +} + +void* IonICEntry::canonicalNativeAddrFor(void* ptr) const { return ptr; } + +bool IonICEntry::callStackAtAddr(JSRuntime* rt, void* ptr, + BytecodeLocationVector& results, + uint32_t* depth) const { + const IonEntry& entry = IonEntryForIonIC(rt, this); + return entry.callStackAtAddr(rejoinAddr(), results, depth); +} + +uint32_t IonICEntry::callStackAtAddr(JSRuntime* rt, void* ptr, + const char** results, + uint32_t maxResults) const { + const IonEntry& entry = IonEntryForIonIC(rt, this); + return entry.callStackAtAddr(rejoinAddr(), results, maxResults); +} + +uint64_t IonICEntry::lookupRealmID(JSRuntime* rt, void* ptr) const { + const IonEntry& entry = IonEntryForIonIC(rt, this); + return entry.lookupRealmID(rejoinAddr()); +} + +void* BaselineEntry::canonicalNativeAddrFor(void* ptr) const { + // TODO: We can't yet normalize Baseline addresses until we unify + // BaselineScript's PCMappingEntries with JitcodeGlobalTable. + return ptr; +} + +bool BaselineEntry::callStackAtAddr(void* ptr, BytecodeLocationVector& results, + uint32_t* depth) const { + MOZ_ASSERT(containsPointer(ptr)); + MOZ_ASSERT(script_->hasBaselineScript()); + + uint8_t* addr = reinterpret_cast<uint8_t*>(ptr); + jsbytecode* pc = + script_->baselineScript()->approximatePcForNativeAddress(script_, addr); + if (!results.append(BytecodeLocation(script_, pc))) { + return false; + } + + *depth = 1; + + return true; +} + +uint32_t BaselineEntry::callStackAtAddr(void* ptr, const char** results, + uint32_t maxResults) const { + MOZ_ASSERT(containsPointer(ptr)); + MOZ_ASSERT(maxResults >= 1); + + results[0] = str(); + return 1; +} + +uint64_t BaselineEntry::lookupRealmID() const { + return script_->realm()->creationOptions().profilerRealmID(); +} + +void* BaselineInterpreterEntry::canonicalNativeAddrFor(void* ptr) const { + return ptr; +} + +bool BaselineInterpreterEntry::callStackAtAddr(void* ptr, + BytecodeLocationVector& results, + uint32_t* depth) const { + MOZ_CRASH("shouldn't be called for BaselineInterpreter entries"); +} + +uint32_t BaselineInterpreterEntry::callStackAtAddr(void* ptr, + const char** results, + uint32_t maxResults) const { + MOZ_CRASH("shouldn't be called for BaselineInterpreter entries"); +} + +uint64_t BaselineInterpreterEntry::lookupRealmID() const { + MOZ_CRASH("shouldn't be called for BaselineInterpreter entries"); +} + +const JitcodeGlobalEntry* JitcodeGlobalTable::lookupForSampler( + void* ptr, JSRuntime* rt, uint64_t samplePosInBuffer) { + JitcodeGlobalEntry* entry = lookupInternal(ptr); + if (!entry) { + return nullptr; + } + + entry->setSamplePositionInBuffer(samplePosInBuffer); + + // IonIC entries must keep their corresponding Ion entries alive. + if (entry->isIonIC()) { + IonEntry& ionEntry = IonEntryForIonIC(rt, &entry->asIonIC()); + ionEntry.setSamplePositionInBuffer(samplePosInBuffer); + } + + // JitcodeGlobalEntries are marked at the end of the mark phase. A read + // barrier is not needed. Any JS frames sampled during the sweep phase of + // the GC must be on stack, and on-stack frames must already be marked at + // the beginning of the sweep phase. It's not possible to assert this here + // as we may be off main thread when called from the gecko profiler. + + return entry; +} + +JitcodeGlobalEntry* JitcodeGlobalTable::lookupInternal(void* ptr) { + // Search for an entry containing the one-byte range starting at |ptr|. + JitCodeRange range(ptr, static_cast<uint8_t*>(ptr) + 1); + + if (JitCodeRange** entry = tree_.maybeLookup(&range)) { + MOZ_ASSERT((*entry)->containsPointer(ptr)); + return static_cast<JitcodeGlobalEntry*>(*entry); + } + + return nullptr; +} + +bool JitcodeGlobalTable::addEntry(UniqueJitcodeGlobalEntry entry) { + MOZ_ASSERT(entry->isIon() || entry->isIonIC() || entry->isBaseline() || + entry->isBaselineInterpreter() || entry->isDummy()); + + // Assert the new entry does not have a code range that's equal to (or + // contained in) one of the existing entries, because that would confuse the + // AVL tree. + MOZ_ASSERT(!tree_.maybeLookup(entry.get())); + + // Suppress profiler sampling while data structures are being mutated. + AutoSuppressProfilerSampling suppressSampling(TlsContext.get()); + + if (!entries_.append(std::move(entry))) { + return false; + } + if (!tree_.insert(entries_.back().get())) { + entries_.popBack(); + return false; + } + + return true; +} + +void JitcodeGlobalTable::setAllEntriesAsExpired() { + AutoSuppressProfilerSampling suppressSampling(TlsContext.get()); + for (EntryVector::Range r(entries_.all()); !r.empty(); r.popFront()) { + auto& entry = r.front(); + entry->setAsExpired(); + } +} + +bool JitcodeGlobalTable::markIteratively(GCMarker* marker) { + // JitcodeGlobalTable must keep entries that are in the sampler buffer + // alive. This conditionality is akin to holding the entries weakly. + // + // If this table were marked at the beginning of the mark phase, then + // sampling would require a read barrier for sampling in between + // incremental GC slices. However, invoking read barriers from the sampler + // is wildly unsafe. The sampler may run at any time, including during GC + // itself. + // + // Instead, JitcodeGlobalTable is marked at the beginning of the sweep + // phase, along with weak references. The key assumption is the + // following. At the beginning of the sweep phase, any JS frames that the + // sampler may put in its buffer that are not already there at the + // beginning of the mark phase must have already been marked, as either 1) + // the frame was on-stack at the beginning of the sweep phase, or 2) the + // frame was pushed between incremental sweep slices. Frames of case 1) + // are already marked. Frames of case 2) must have been reachable to have + // been newly pushed, and thus are already marked. + // + // The approach above obviates the need for read barriers. The assumption + // above is checked in JitcodeGlobalTable::lookupForSampler. + + MOZ_ASSERT(!JS::RuntimeHeapIsMinorCollecting()); + + AutoSuppressProfilerSampling suppressSampling(TlsContext.get()); + + // If the profiler is off, rangeStart will be Nothing() and all entries are + // considered to be expired. + Maybe<uint64_t> rangeStart = + marker->runtime()->profilerSampleBufferRangeStart(); + + bool markedAny = false; + for (EntryVector::Range r(entries_.all()); !r.empty(); r.popFront()) { + auto& entry = r.front(); + + // If an entry is not sampled, reset its buffer position to the invalid + // position, and conditionally mark the rest of the entry if its + // JitCode is not already marked. This conditional marking ensures + // that so long as the JitCode *may* be sampled, we keep any + // information that may be handed out to the sampler, like tracked + // types used by optimizations and scripts used for pc to line number + // mapping, alive as well. + if (!rangeStart || !entry->isSampled(*rangeStart)) { + entry->setAsExpired(); + if (!entry->isJitcodeMarkedFromAnyThread(marker->runtime())) { + continue; + } + } + + // The table is runtime-wide. Not all zones may be participating in + // the GC. + if (!entry->zone()->isCollecting() || entry->zone()->isGCFinished()) { + continue; + } + + markedAny |= entry->trace(marker->tracer()); + } + + return markedAny; +} + +void JitcodeGlobalTable::traceWeak(JSRuntime* rt, JSTracer* trc) { + AutoSuppressProfilerSampling suppressSampling(rt->mainContextFromOwnThread()); + + entries_.eraseIf([&](auto& entry) { + if (!entry->zone()->isCollecting() || entry->zone()->isGCFinished()) { + return false; + } + + if (TraceManuallyBarrieredWeakEdge( + trc, entry->jitcodePtr(), + "JitcodeGlobalTable::JitcodeGlobalEntry::jitcode_")) { + entry->traceWeak(trc); + return false; + } + + // We have to remove the entry. +#ifdef DEBUG + Maybe<uint64_t> rangeStart = rt->profilerSampleBufferRangeStart(); + MOZ_ASSERT_IF(rangeStart, !entry->isSampled(*rangeStart)); +#endif + tree_.remove(entry.get()); + return true; + }); + + MOZ_ASSERT(tree_.empty() == entries_.empty()); +} + +bool JitcodeGlobalEntry::traceJitcode(JSTracer* trc) { + if (!IsMarkedUnbarriered(trc->runtime(), jitcode_)) { + TraceManuallyBarrieredEdge(trc, &jitcode_, + "jitcodglobaltable-baseentry-jitcode"); + return true; + } + return false; +} + +bool JitcodeGlobalEntry::isJitcodeMarkedFromAnyThread(JSRuntime* rt) { + return IsMarkedUnbarriered(rt, jitcode_); +} + +bool BaselineEntry::trace(JSTracer* trc) { + if (!IsMarkedUnbarriered(trc->runtime(), script_)) { + TraceManuallyBarrieredEdge(trc, &script_, + "jitcodeglobaltable-baselineentry-script"); + return true; + } + return false; +} + +void BaselineEntry::traceWeak(JSTracer* trc) { + MOZ_ALWAYS_TRUE( + TraceManuallyBarrieredWeakEdge(trc, &script_, "BaselineEntry::script_")); +} + +bool IonEntry::trace(JSTracer* trc) { + bool tracedAny = false; + + JSRuntime* rt = trc->runtime(); + for (auto& pair : scriptList_) { + if (!IsMarkedUnbarriered(rt, pair.script)) { + TraceManuallyBarrieredEdge(trc, &pair.script, + "jitcodeglobaltable-ionentry-script"); + tracedAny = true; + } + } + + return tracedAny; +} + +void IonEntry::traceWeak(JSTracer* trc) { + for (auto& pair : scriptList_) { + JSScript** scriptp = &pair.script; + MOZ_ALWAYS_TRUE( + TraceManuallyBarrieredWeakEdge(trc, scriptp, "IonEntry script")); + } +} + +bool IonICEntry::trace(JSTracer* trc) { + IonEntry& entry = IonEntryForIonIC(trc->runtime(), this); + return entry.trace(trc); +} + +void IonICEntry::traceWeak(JSTracer* trc) { + IonEntry& entry = IonEntryForIonIC(trc->runtime(), this); + entry.traceWeak(trc); +} + +[[nodiscard]] bool JitcodeGlobalEntry::callStackAtAddr( + JSRuntime* rt, void* ptr, BytecodeLocationVector& results, + uint32_t* depth) const { + switch (kind()) { + case Kind::Ion: + return asIon().callStackAtAddr(ptr, results, depth); + case Kind::IonIC: + return asIonIC().callStackAtAddr(rt, ptr, results, depth); + case Kind::Baseline: + return asBaseline().callStackAtAddr(ptr, results, depth); + case Kind::BaselineInterpreter: + return asBaselineInterpreter().callStackAtAddr(ptr, results, depth); + case Kind::Dummy: + return asDummy().callStackAtAddr(rt, ptr, results, depth); + } + MOZ_CRASH("Invalid kind"); +} + +uint32_t JitcodeGlobalEntry::callStackAtAddr(JSRuntime* rt, void* ptr, + const char** results, + uint32_t maxResults) const { + switch (kind()) { + case Kind::Ion: + return asIon().callStackAtAddr(ptr, results, maxResults); + case Kind::IonIC: + return asIonIC().callStackAtAddr(rt, ptr, results, maxResults); + case Kind::Baseline: + return asBaseline().callStackAtAddr(ptr, results, maxResults); + case Kind::BaselineInterpreter: + return asBaselineInterpreter().callStackAtAddr(ptr, results, maxResults); + case Kind::Dummy: + return asDummy().callStackAtAddr(rt, ptr, results, maxResults); + } + MOZ_CRASH("Invalid kind"); +} + +uint64_t JitcodeGlobalEntry::lookupRealmID(JSRuntime* rt, void* ptr) const { + switch (kind()) { + case Kind::Ion: + return asIon().lookupRealmID(ptr); + case Kind::IonIC: + return asIonIC().lookupRealmID(rt, ptr); + case Kind::Baseline: + return asBaseline().lookupRealmID(); + case Kind::Dummy: + return asDummy().lookupRealmID(); + case Kind::BaselineInterpreter: + break; + } + MOZ_CRASH("Invalid kind"); +} + +bool JitcodeGlobalEntry::trace(JSTracer* trc) { + bool tracedAny = traceJitcode(trc); + switch (kind()) { + case Kind::Ion: + tracedAny |= asIon().trace(trc); + break; + case Kind::IonIC: + tracedAny |= asIonIC().trace(trc); + break; + case Kind::Baseline: + tracedAny |= asBaseline().trace(trc); + break; + case Kind::BaselineInterpreter: + case Kind::Dummy: + break; + } + return tracedAny; +} + +void JitcodeGlobalEntry::traceWeak(JSTracer* trc) { + switch (kind()) { + case Kind::Ion: + asIon().traceWeak(trc); + break; + case Kind::IonIC: + asIonIC().traceWeak(trc); + break; + case Kind::Baseline: + asBaseline().traceWeak(trc); + break; + case Kind::BaselineInterpreter: + case Kind::Dummy: + break; + } +} + +void* JitcodeGlobalEntry::canonicalNativeAddrFor(JSRuntime* rt, + void* ptr) const { + switch (kind()) { + case Kind::Ion: + return asIon().canonicalNativeAddrFor(ptr); + case Kind::IonIC: + return asIonIC().canonicalNativeAddrFor(ptr); + case Kind::Baseline: + return asBaseline().canonicalNativeAddrFor(ptr); + case Kind::Dummy: + return asDummy().canonicalNativeAddrFor(rt, ptr); + case Kind::BaselineInterpreter: + break; + } + MOZ_CRASH("Invalid kind"); +} + +// static +void JitcodeGlobalEntry::DestroyPolicy::operator()(JitcodeGlobalEntry* entry) { + switch (entry->kind()) { + case JitcodeGlobalEntry::Kind::Ion: + js_delete(&entry->asIon()); + break; + case JitcodeGlobalEntry::Kind::IonIC: + js_delete(&entry->asIonIC()); + break; + case JitcodeGlobalEntry::Kind::Baseline: + js_delete(&entry->asBaseline()); + break; + case JitcodeGlobalEntry::Kind::BaselineInterpreter: + js_delete(&entry->asBaselineInterpreter()); + break; + case JitcodeGlobalEntry::Kind::Dummy: + js_delete(&entry->asDummy()); + break; + } +} + +/* static */ +void JitcodeRegionEntry::WriteHead(CompactBufferWriter& writer, + uint32_t nativeOffset, uint8_t scriptDepth) { + writer.writeUnsigned(nativeOffset); + writer.writeByte(scriptDepth); +} + +/* static */ +void JitcodeRegionEntry::ReadHead(CompactBufferReader& reader, + uint32_t* nativeOffset, + uint8_t* scriptDepth) { + *nativeOffset = reader.readUnsigned(); + *scriptDepth = reader.readByte(); +} + +/* static */ +void JitcodeRegionEntry::WriteScriptPc(CompactBufferWriter& writer, + uint32_t scriptIdx, uint32_t pcOffset) { + writer.writeUnsigned(scriptIdx); + writer.writeUnsigned(pcOffset); +} + +/* static */ +void JitcodeRegionEntry::ReadScriptPc(CompactBufferReader& reader, + uint32_t* scriptIdx, uint32_t* pcOffset) { + *scriptIdx = reader.readUnsigned(); + *pcOffset = reader.readUnsigned(); +} + +/* static */ +void JitcodeRegionEntry::WriteDelta(CompactBufferWriter& writer, + uint32_t nativeDelta, int32_t pcDelta) { + if (pcDelta >= 0) { + // 1 and 2-byte formats possible. + + // NNNN-BBB0 + if (pcDelta <= ENC1_PC_DELTA_MAX && nativeDelta <= ENC1_NATIVE_DELTA_MAX) { + uint8_t encVal = ENC1_MASK_VAL | (pcDelta << ENC1_PC_DELTA_SHIFT) | + (nativeDelta << ENC1_NATIVE_DELTA_SHIFT); + writer.writeByte(encVal); + return; + } + + // NNNN-NNNN BBBB-BB01 + if (pcDelta <= ENC2_PC_DELTA_MAX && nativeDelta <= ENC2_NATIVE_DELTA_MAX) { + uint16_t encVal = ENC2_MASK_VAL | (pcDelta << ENC2_PC_DELTA_SHIFT) | + (nativeDelta << ENC2_NATIVE_DELTA_SHIFT); + writer.writeByte(encVal & 0xff); + writer.writeByte((encVal >> 8) & 0xff); + return; + } + } + + // NNNN-NNNN NNNB-BBBB BBBB-B011 + if (pcDelta >= ENC3_PC_DELTA_MIN && pcDelta <= ENC3_PC_DELTA_MAX && + nativeDelta <= ENC3_NATIVE_DELTA_MAX) { + uint32_t encVal = + ENC3_MASK_VAL | + ((uint32_t(pcDelta) << ENC3_PC_DELTA_SHIFT) & ENC3_PC_DELTA_MASK) | + (nativeDelta << ENC3_NATIVE_DELTA_SHIFT); + writer.writeByte(encVal & 0xff); + writer.writeByte((encVal >> 8) & 0xff); + writer.writeByte((encVal >> 16) & 0xff); + return; + } + + // NNNN-NNNN NNNN-NNNN BBBB-BBBB BBBB-B111 + if (pcDelta >= ENC4_PC_DELTA_MIN && pcDelta <= ENC4_PC_DELTA_MAX && + nativeDelta <= ENC4_NATIVE_DELTA_MAX) { + uint32_t encVal = + ENC4_MASK_VAL | + ((uint32_t(pcDelta) << ENC4_PC_DELTA_SHIFT) & ENC4_PC_DELTA_MASK) | + (nativeDelta << ENC4_NATIVE_DELTA_SHIFT); + writer.writeByte(encVal & 0xff); + writer.writeByte((encVal >> 8) & 0xff); + writer.writeByte((encVal >> 16) & 0xff); + writer.writeByte((encVal >> 24) & 0xff); + return; + } + + // Should never get here. + MOZ_CRASH("pcDelta/nativeDelta values are too large to encode."); +} + +/* static */ +void JitcodeRegionEntry::ReadDelta(CompactBufferReader& reader, + uint32_t* nativeDelta, int32_t* pcDelta) { + // NB: + // It's possible to get nativeDeltas with value 0 in two cases: + // + // 1. The last region's run. This is because the region table's start + // must be 4-byte aligned, and we must insert padding bytes to align the + // payload section before emitting the table. + // + // 2. A zero-offset nativeDelta with a negative pcDelta. + // + // So if nativeDelta is zero, then pcDelta must be <= 0. + + // NNNN-BBB0 + const uint32_t firstByte = reader.readByte(); + if ((firstByte & ENC1_MASK) == ENC1_MASK_VAL) { + uint32_t encVal = firstByte; + *nativeDelta = encVal >> ENC1_NATIVE_DELTA_SHIFT; + *pcDelta = (encVal & ENC1_PC_DELTA_MASK) >> ENC1_PC_DELTA_SHIFT; + MOZ_ASSERT_IF(*nativeDelta == 0, *pcDelta <= 0); + return; + } + + // NNNN-NNNN BBBB-BB01 + const uint32_t secondByte = reader.readByte(); + if ((firstByte & ENC2_MASK) == ENC2_MASK_VAL) { + uint32_t encVal = firstByte | secondByte << 8; + *nativeDelta = encVal >> ENC2_NATIVE_DELTA_SHIFT; + *pcDelta = (encVal & ENC2_PC_DELTA_MASK) >> ENC2_PC_DELTA_SHIFT; + MOZ_ASSERT(*pcDelta != 0); + MOZ_ASSERT_IF(*nativeDelta == 0, *pcDelta <= 0); + return; + } + + // NNNN-NNNN NNNB-BBBB BBBB-B011 + const uint32_t thirdByte = reader.readByte(); + if ((firstByte & ENC3_MASK) == ENC3_MASK_VAL) { + uint32_t encVal = firstByte | secondByte << 8 | thirdByte << 16; + *nativeDelta = encVal >> ENC3_NATIVE_DELTA_SHIFT; + + uint32_t pcDeltaU = (encVal & ENC3_PC_DELTA_MASK) >> ENC3_PC_DELTA_SHIFT; + // Fix sign if necessary. + if (pcDeltaU > static_cast<uint32_t>(ENC3_PC_DELTA_MAX)) { + pcDeltaU |= ~ENC3_PC_DELTA_MAX; + } + *pcDelta = pcDeltaU; + MOZ_ASSERT(*pcDelta != 0); + MOZ_ASSERT_IF(*nativeDelta == 0, *pcDelta <= 0); + return; + } + + // NNNN-NNNN NNNN-NNNN BBBB-BBBB BBBB-B111 + MOZ_ASSERT((firstByte & ENC4_MASK) == ENC4_MASK_VAL); + const uint32_t fourthByte = reader.readByte(); + uint32_t encVal = + firstByte | secondByte << 8 | thirdByte << 16 | fourthByte << 24; + *nativeDelta = encVal >> ENC4_NATIVE_DELTA_SHIFT; + + uint32_t pcDeltaU = (encVal & ENC4_PC_DELTA_MASK) >> ENC4_PC_DELTA_SHIFT; + // fix sign if necessary + if (pcDeltaU > static_cast<uint32_t>(ENC4_PC_DELTA_MAX)) { + pcDeltaU |= ~ENC4_PC_DELTA_MAX; + } + *pcDelta = pcDeltaU; + + MOZ_ASSERT(*pcDelta != 0); + MOZ_ASSERT_IF(*nativeDelta == 0, *pcDelta <= 0); +} + +/* static */ +uint32_t JitcodeRegionEntry::ExpectedRunLength(const NativeToBytecode* entry, + const NativeToBytecode* end) { + MOZ_ASSERT(entry < end); + + // We always use the first entry, so runLength starts at 1 + uint32_t runLength = 1; + + uint32_t curNativeOffset = entry->nativeOffset.offset(); + uint32_t curBytecodeOffset = entry->tree->script()->pcToOffset(entry->pc); + + for (auto nextEntry = entry + 1; nextEntry != end; nextEntry += 1) { + // If the next run moves to a different inline site, stop the run. + if (nextEntry->tree != entry->tree) { + break; + } + + uint32_t nextNativeOffset = nextEntry->nativeOffset.offset(); + uint32_t nextBytecodeOffset = + nextEntry->tree->script()->pcToOffset(nextEntry->pc); + MOZ_ASSERT(nextNativeOffset >= curNativeOffset); + + uint32_t nativeDelta = nextNativeOffset - curNativeOffset; + int32_t bytecodeDelta = + int32_t(nextBytecodeOffset) - int32_t(curBytecodeOffset); + + // If deltas are too large (very unlikely), stop the run. + if (!IsDeltaEncodeable(nativeDelta, bytecodeDelta)) { + break; + } + + runLength++; + + // If the run has grown to its maximum length, stop the run. + if (runLength == MAX_RUN_LENGTH) { + break; + } + + curNativeOffset = nextNativeOffset; + curBytecodeOffset = nextBytecodeOffset; + } + + return runLength; +} + +struct JitcodeMapBufferWriteSpewer { +#ifdef JS_JITSPEW + CompactBufferWriter* writer; + uint32_t startPos; + + static const uint32_t DumpMaxBytes = 50; + + explicit JitcodeMapBufferWriteSpewer(CompactBufferWriter& w) + : writer(&w), startPos(writer->length()) {} + + void spewAndAdvance(const char* name) { + if (writer->oom()) { + return; + } + + uint32_t curPos = writer->length(); + const uint8_t* start = writer->buffer() + startPos; + const uint8_t* end = writer->buffer() + curPos; + const char* MAP = "0123456789ABCDEF"; + uint32_t bytes = end - start; + + char buffer[DumpMaxBytes * 3]; + for (uint32_t i = 0; i < bytes; i++) { + buffer[i * 3] = MAP[(start[i] >> 4) & 0xf]; + buffer[i * 3 + 1] = MAP[(start[i] >> 0) & 0xf]; + buffer[i * 3 + 2] = ' '; + } + if (bytes >= DumpMaxBytes) { + buffer[DumpMaxBytes * 3 - 1] = '\0'; + } else { + buffer[bytes * 3 - 1] = '\0'; + } + + JitSpew(JitSpew_Profiling, "%s@%d[%d bytes] - %s", name, int(startPos), + int(bytes), buffer); + + // Move to the end of the current buffer. + startPos = writer->length(); + } +#else // !JS_JITSPEW + explicit JitcodeMapBufferWriteSpewer(CompactBufferWriter& w) {} + void spewAndAdvance(const char* name) {} +#endif // JS_JITSPEW +}; + +// Write a run, starting at the given NativeToBytecode entry, into the given +// buffer writer. +/* static */ +bool JitcodeRegionEntry::WriteRun(CompactBufferWriter& writer, + const IonEntry::ScriptList& scriptList, + uint32_t runLength, + const NativeToBytecode* entry) { + MOZ_ASSERT(runLength > 0); + MOZ_ASSERT(runLength <= MAX_RUN_LENGTH); + + // Calculate script depth. + MOZ_ASSERT(entry->tree->depth() <= 0xff); + uint8_t scriptDepth = entry->tree->depth(); + uint32_t regionNativeOffset = entry->nativeOffset.offset(); + + JitcodeMapBufferWriteSpewer spewer(writer); + + // Write the head info. + JitSpew(JitSpew_Profiling, " Head Info: nativeOffset=%d scriptDepth=%d", + int(regionNativeOffset), int(scriptDepth)); + WriteHead(writer, regionNativeOffset, scriptDepth); + spewer.spewAndAdvance(" "); + + // Write each script/pc pair. + { + InlineScriptTree* curTree = entry->tree; + jsbytecode* curPc = entry->pc; + for (uint8_t i = 0; i < scriptDepth; i++) { + // Find the index of the script within the list. + // NB: scriptList is guaranteed to contain curTree->script() + uint32_t scriptIdx = 0; + for (; scriptIdx < scriptList.length(); scriptIdx++) { + if (scriptList[scriptIdx].script == curTree->script()) { + break; + } + } + MOZ_ASSERT(scriptIdx < scriptList.length()); + + uint32_t pcOffset = curTree->script()->pcToOffset(curPc); + + JitSpew(JitSpew_Profiling, " Script/PC %d: scriptIdx=%d pcOffset=%d", + int(i), int(scriptIdx), int(pcOffset)); + WriteScriptPc(writer, scriptIdx, pcOffset); + spewer.spewAndAdvance(" "); + + MOZ_ASSERT_IF(i < scriptDepth - 1, curTree->hasCaller()); + curPc = curTree->callerPc(); + curTree = curTree->caller(); + } + } + + // Start writing runs. + uint32_t curNativeOffset = entry->nativeOffset.offset(); + uint32_t curBytecodeOffset = entry->tree->script()->pcToOffset(entry->pc); + + JitSpew(JitSpew_Profiling, + " Writing Delta Run from nativeOffset=%d bytecodeOffset=%d", + int(curNativeOffset), int(curBytecodeOffset)); + + // Skip first entry because it is implicit in the header. Start at subsequent + // entry. + for (uint32_t i = 1; i < runLength; i++) { + MOZ_ASSERT(entry[i].tree == entry->tree); + + uint32_t nextNativeOffset = entry[i].nativeOffset.offset(); + uint32_t nextBytecodeOffset = + entry[i].tree->script()->pcToOffset(entry[i].pc); + MOZ_ASSERT(nextNativeOffset >= curNativeOffset); + + uint32_t nativeDelta = nextNativeOffset - curNativeOffset; + int32_t bytecodeDelta = + int32_t(nextBytecodeOffset) - int32_t(curBytecodeOffset); + MOZ_ASSERT(IsDeltaEncodeable(nativeDelta, bytecodeDelta)); + + JitSpew(JitSpew_Profiling, + " RunEntry native: %d-%d [%d] bytecode: %d-%d [%d]", + int(curNativeOffset), int(nextNativeOffset), int(nativeDelta), + int(curBytecodeOffset), int(nextBytecodeOffset), + int(bytecodeDelta)); + WriteDelta(writer, nativeDelta, bytecodeDelta); + + // Spew the bytecode in these ranges. + if (curBytecodeOffset < nextBytecodeOffset) { + JitSpewStart(JitSpew_Profiling, " OPS: "); + uint32_t curBc = curBytecodeOffset; + while (curBc < nextBytecodeOffset) { + jsbytecode* pc = entry[i].tree->script()->offsetToPC(curBc); +#ifdef JS_JITSPEW + JSOp op = JSOp(*pc); + JitSpewCont(JitSpew_Profiling, "%s ", CodeName(op)); +#endif + curBc += GetBytecodeLength(pc); + } + JitSpewFin(JitSpew_Profiling); + } + spewer.spewAndAdvance(" "); + + curNativeOffset = nextNativeOffset; + curBytecodeOffset = nextBytecodeOffset; + } + + if (writer.oom()) { + return false; + } + + return true; +} + +void JitcodeRegionEntry::unpack() { + CompactBufferReader reader(data_, end_); + ReadHead(reader, &nativeOffset_, &scriptDepth_); + MOZ_ASSERT(scriptDepth_ > 0); + + scriptPcStack_ = reader.currentPosition(); + // Skip past script/pc stack + for (unsigned i = 0; i < scriptDepth_; i++) { + uint32_t scriptIdx, pcOffset; + ReadScriptPc(reader, &scriptIdx, &pcOffset); + } + + deltaRun_ = reader.currentPosition(); +} + +uint32_t JitcodeRegionEntry::findPcOffset(uint32_t queryNativeOffset, + uint32_t startPcOffset) const { + DeltaIterator iter = deltaIterator(); + uint32_t curNativeOffset = nativeOffset(); + uint32_t curPcOffset = startPcOffset; + while (iter.hasMore()) { + uint32_t nativeDelta; + int32_t pcDelta; + iter.readNext(&nativeDelta, &pcDelta); + + // The start address of the next delta-run entry is counted towards + // the current delta-run entry, because return addresses should + // associate with the bytecode op prior (the call) not the op after. + if (queryNativeOffset <= curNativeOffset + nativeDelta) { + break; + } + curNativeOffset += nativeDelta; + curPcOffset += pcDelta; + } + return curPcOffset; +} + +uint32_t JitcodeIonTable::findRegionEntry(uint32_t nativeOffset) const { + static const uint32_t LINEAR_SEARCH_THRESHOLD = 8; + uint32_t regions = numRegions(); + MOZ_ASSERT(regions > 0); + + // For small region lists, just search linearly. + if (regions <= LINEAR_SEARCH_THRESHOLD) { + JitcodeRegionEntry previousEntry = regionEntry(0); + for (uint32_t i = 1; i < regions; i++) { + JitcodeRegionEntry nextEntry = regionEntry(i); + MOZ_ASSERT(nextEntry.nativeOffset() >= previousEntry.nativeOffset()); + + // See note in binary-search code below about why we use '<=' here + // instead of '<'. Short explanation: regions are closed at their + // ending addresses, and open at their starting addresses. + if (nativeOffset <= nextEntry.nativeOffset()) { + return i - 1; + } + + previousEntry = nextEntry; + } + // If nothing found, assume it falls within last region. + return regions - 1; + } + + // For larger ones, binary search the region table. + uint32_t idx = 0; + uint32_t count = regions; + while (count > 1) { + uint32_t step = count / 2; + uint32_t mid = idx + step; + JitcodeRegionEntry midEntry = regionEntry(mid); + + // A region memory range is closed at its ending address, not starting + // address. This is because the return address for calls must associate + // with the call's bytecode PC, not the PC of the bytecode operator after + // the call. + // + // So a query is < an entry if the query nativeOffset is <= the start + // address of the entry, and a query is >= an entry if the query + // nativeOffset is > the start address of an entry. + if (nativeOffset <= midEntry.nativeOffset()) { + // Target entry is below midEntry. + count = step; + } else { // if (nativeOffset > midEntry.nativeOffset()) + // Target entry is at midEntry or above. + idx = mid; + count -= step; + } + } + return idx; +} + +/* static */ +bool JitcodeIonTable::WriteIonTable(CompactBufferWriter& writer, + const IonEntry::ScriptList& scriptList, + const NativeToBytecode* start, + const NativeToBytecode* end, + uint32_t* tableOffsetOut, + uint32_t* numRegionsOut) { + MOZ_ASSERT(tableOffsetOut != nullptr); + MOZ_ASSERT(numRegionsOut != nullptr); + MOZ_ASSERT(writer.length() == 0); + MOZ_ASSERT(scriptList.length() > 0); + + JitSpew(JitSpew_Profiling, + "Writing native to bytecode map for %s:%u:%u (%zu entries)", + scriptList[0].script->filename(), scriptList[0].script->lineno(), + scriptList[0].script->column(), + mozilla::PointerRangeSize(start, end)); + + JitSpew(JitSpew_Profiling, " ScriptList of size %u", + unsigned(scriptList.length())); + for (uint32_t i = 0; i < scriptList.length(); i++) { + JitSpew(JitSpew_Profiling, " Script %u - %s:%u:%u", i, + scriptList[i].script->filename(), scriptList[i].script->lineno(), + scriptList[i].script->column()); + } + + // Write out runs first. Keep a vector tracking the positive offsets from + // payload start to the run. + const NativeToBytecode* curEntry = start; + js::Vector<uint32_t, 32, SystemAllocPolicy> runOffsets; + + while (curEntry != end) { + // Calculate the length of the next run. + uint32_t runLength = JitcodeRegionEntry::ExpectedRunLength(curEntry, end); + MOZ_ASSERT(runLength > 0); + MOZ_ASSERT(runLength <= uintptr_t(end - curEntry)); + JitSpew(JitSpew_Profiling, " Run at entry %d, length %d, buffer offset %d", + int(curEntry - start), int(runLength), int(writer.length())); + + // Store the offset of the run. + if (!runOffsets.append(writer.length())) { + return false; + } + + // Encode the run. + if (!JitcodeRegionEntry::WriteRun(writer, scriptList, runLength, + curEntry)) { + return false; + } + + curEntry += runLength; + } + + // Done encoding regions. About to start table. Ensure we are aligned to 4 + // bytes since table is composed of uint32_t values. + uint32_t padding = sizeof(uint32_t) - (writer.length() % sizeof(uint32_t)); + if (padding == sizeof(uint32_t)) { + padding = 0; + } + JitSpew(JitSpew_Profiling, " Padding %d bytes after run @%d", int(padding), + int(writer.length())); + for (uint32_t i = 0; i < padding; i++) { + writer.writeByte(0); + } + + // Now at start of table. + uint32_t tableOffset = writer.length(); + + // The table being written at this point will be accessed directly via + // uint32_t pointers, so all writes below use native endianness. + + // Write out numRegions + JitSpew(JitSpew_Profiling, " Writing numRuns=%d", int(runOffsets.length())); + writer.writeNativeEndianUint32_t(runOffsets.length()); + + // Write out region offset table. The offsets in |runOffsets| are currently + // forward offsets from the beginning of the buffer. We convert them to + // backwards offsets from the start of the table before writing them into + // their table entries. + for (uint32_t i = 0; i < runOffsets.length(); i++) { + JitSpew(JitSpew_Profiling, " Run %d offset=%d backOffset=%d @%d", int(i), + int(runOffsets[i]), int(tableOffset - runOffsets[i]), + int(writer.length())); + writer.writeNativeEndianUint32_t(tableOffset - runOffsets[i]); + } + + if (writer.oom()) { + return false; + } + + *tableOffsetOut = tableOffset; + *numRegionsOut = runOffsets.length(); + return true; +} + +} // namespace jit +} // namespace js + +JS::ProfiledFrameHandle::ProfiledFrameHandle(JSRuntime* rt, + js::jit::JitcodeGlobalEntry& entry, + void* addr, const char* label, + uint32_t depth) + : rt_(rt), + entry_(entry), + addr_(addr), + canonicalAddr_(nullptr), + label_(label), + depth_(depth) { + if (!canonicalAddr_) { + canonicalAddr_ = entry_.canonicalNativeAddrFor(rt_, addr_); + } +} + +JS_PUBLIC_API JS::ProfilingFrameIterator::FrameKind +JS::ProfiledFrameHandle::frameKind() const { + if (entry_.isBaselineInterpreter()) { + return JS::ProfilingFrameIterator::Frame_BaselineInterpreter; + } + if (entry_.isBaseline()) { + return JS::ProfilingFrameIterator::Frame_Baseline; + } + return JS::ProfilingFrameIterator::Frame_Ion; +} + +JS_PUBLIC_API uint64_t JS::ProfiledFrameHandle::realmID() const { + return entry_.lookupRealmID(rt_, addr_); +} + +JS_PUBLIC_API JS::ProfiledFrameRange JS::GetProfiledFrames(JSContext* cx, + void* addr) { + JSRuntime* rt = cx->runtime(); + js::jit::JitcodeGlobalTable* table = + rt->jitRuntime()->getJitcodeGlobalTable(); + js::jit::JitcodeGlobalEntry* entry = table->lookup(addr); + + ProfiledFrameRange result(rt, addr, entry); + + if (entry) { + result.depth_ = entry->callStackAtAddr(rt, addr, result.labels_, + MOZ_ARRAY_LENGTH(result.labels_)); + } + return result; +} + +JS::ProfiledFrameHandle JS::ProfiledFrameRange::Iter::operator*() const { + // The iterator iterates in high depth to low depth order. index_ goes up, + // and the depth we need to pass to ProfiledFrameHandle goes down. + uint32_t depth = range_.depth_ - 1 - index_; + return ProfiledFrameHandle(range_.rt_, *range_.entry_, range_.addr_, + range_.labels_[depth], depth); +} |