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Diffstat (limited to 'js/src/wasm/WasmDebug.cpp')
| -rw-r--r-- | js/src/wasm/WasmDebug.cpp | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/js/src/wasm/WasmDebug.cpp b/js/src/wasm/WasmDebug.cpp new file mode 100644 index 0000000000..81d10aec08 --- /dev/null +++ b/js/src/wasm/WasmDebug.cpp @@ -0,0 +1,496 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * + * Copyright 2016 Mozilla Foundation + * + * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "wasm/WasmDebug.h" + +#include "mozilla/BinarySearch.h" + +#include "debugger/Debugger.h" +#include "ds/Sort.h" +#include "jit/AutoWritableJitCode.h" +#include "jit/ExecutableAllocator.h" +#include "jit/MacroAssembler.h" +#include "wasm/WasmInstance.h" +#include "wasm/WasmStubs.h" +#include "wasm/WasmValidate.h" + +#include "gc/FreeOp-inl.h" + +using namespace js; +using namespace js::jit; +using namespace js::wasm; + +using mozilla::BinarySearchIf; + +DebugState::DebugState(const Code& code, const Module& module) + : code_(&code), + module_(&module), + enterFrameTrapsEnabled_(false), + enterAndLeaveFrameTrapsCounter_(0) { + MOZ_ASSERT(code.metadata().debugEnabled); +} + +void DebugState::trace(JSTracer* trc) { + for (auto iter = breakpointSites_.iter(); !iter.done(); iter.next()) { + WasmBreakpointSite* site = iter.get().value(); + site->trace(trc); + } +} + +void DebugState::finalize(JSFreeOp* fop) { + for (auto iter = breakpointSites_.iter(); !iter.done(); iter.next()) { + WasmBreakpointSite* site = iter.get().value(); + site->delete_(fop); + } +} + +static const uint32_t DefaultBinarySourceColumnNumber = 1; + +static const CallSite* SlowCallSiteSearchByOffset(const MetadataTier& metadata, + uint32_t offset) { + for (const CallSite& callSite : metadata.callSites) { + if (callSite.lineOrBytecode() == offset && + callSite.kind() == CallSiteDesc::Breakpoint) { + return &callSite; + } + } + return nullptr; +} + +bool DebugState::getLineOffsets(size_t lineno, Vector<uint32_t>* offsets) { + const CallSite* callsite = + SlowCallSiteSearchByOffset(metadata(Tier::Debug), lineno); + if (callsite && !offsets->append(lineno)) { + return false; + } + return true; +} + +bool DebugState::getAllColumnOffsets(Vector<ExprLoc>* offsets) { + for (const CallSite& callSite : metadata(Tier::Debug).callSites) { + if (callSite.kind() != CallSite::Breakpoint) { + continue; + } + uint32_t offset = callSite.lineOrBytecode(); + if (!offsets->emplaceBack(offset, DefaultBinarySourceColumnNumber, + offset)) { + return false; + } + } + return true; +} + +bool DebugState::getOffsetLocation(uint32_t offset, size_t* lineno, + size_t* column) { + if (!SlowCallSiteSearchByOffset(metadata(Tier::Debug), offset)) { + return false; + } + *lineno = offset; + *column = DefaultBinarySourceColumnNumber; + return true; +} + +bool DebugState::stepModeEnabled(uint32_t funcIndex) const { + return stepperCounters_.lookup(funcIndex).found(); +} + +bool DebugState::incrementStepperCount(JSContext* cx, uint32_t funcIndex) { + const CodeRange& codeRange = + codeRanges(Tier::Debug)[funcToCodeRangeIndex(funcIndex)]; + MOZ_ASSERT(codeRange.isFunction()); + + StepperCounters::AddPtr p = stepperCounters_.lookupForAdd(funcIndex); + if (p) { + MOZ_ASSERT(p->value() > 0); + p->value()++; + return true; + } + if (!stepperCounters_.add(p, funcIndex, 1)) { + ReportOutOfMemory(cx); + return false; + } + + AutoWritableJitCode awjc( + cx->runtime(), code_->segment(Tier::Debug).base() + codeRange.begin(), + codeRange.end() - codeRange.begin()); + + for (const CallSite& callSite : callSites(Tier::Debug)) { + if (callSite.kind() != CallSite::Breakpoint) { + continue; + } + uint32_t offset = callSite.returnAddressOffset(); + if (codeRange.begin() <= offset && offset <= codeRange.end()) { + toggleDebugTrap(offset, true); + } + } + return true; +} + +void DebugState::decrementStepperCount(JSFreeOp* fop, uint32_t funcIndex) { + const CodeRange& codeRange = + codeRanges(Tier::Debug)[funcToCodeRangeIndex(funcIndex)]; + MOZ_ASSERT(codeRange.isFunction()); + + MOZ_ASSERT(!stepperCounters_.empty()); + StepperCounters::Ptr p = stepperCounters_.lookup(funcIndex); + MOZ_ASSERT(p); + if (--p->value()) { + return; + } + + stepperCounters_.remove(p); + + AutoWritableJitCode awjc( + fop->runtime(), code_->segment(Tier::Debug).base() + codeRange.begin(), + codeRange.end() - codeRange.begin()); + + for (const CallSite& callSite : callSites(Tier::Debug)) { + if (callSite.kind() != CallSite::Breakpoint) { + continue; + } + uint32_t offset = callSite.returnAddressOffset(); + if (codeRange.begin() <= offset && offset <= codeRange.end()) { + bool enabled = breakpointSites_.has(offset); + toggleDebugTrap(offset, enabled); + } + } +} + +bool DebugState::hasBreakpointTrapAtOffset(uint32_t offset) { + return SlowCallSiteSearchByOffset(metadata(Tier::Debug), offset); +} + +void DebugState::toggleBreakpointTrap(JSRuntime* rt, uint32_t offset, + bool enabled) { + const CallSite* callSite = + SlowCallSiteSearchByOffset(metadata(Tier::Debug), offset); + if (!callSite) { + return; + } + size_t debugTrapOffset = callSite->returnAddressOffset(); + + const ModuleSegment& codeSegment = code_->segment(Tier::Debug); + const CodeRange* codeRange = + code_->lookupFuncRange(codeSegment.base() + debugTrapOffset); + MOZ_ASSERT(codeRange); + + if (stepperCounters_.lookup(codeRange->funcIndex())) { + return; // no need to toggle when step mode is enabled + } + + AutoWritableJitCode awjc(rt, codeSegment.base(), codeSegment.length()); + toggleDebugTrap(debugTrapOffset, enabled); +} + +WasmBreakpointSite* DebugState::getBreakpointSite(uint32_t offset) const { + WasmBreakpointSiteMap::Ptr p = breakpointSites_.lookup(offset); + if (!p) { + return nullptr; + } + + return p->value(); +} + +WasmBreakpointSite* DebugState::getOrCreateBreakpointSite(JSContext* cx, + Instance* instance, + uint32_t offset) { + WasmBreakpointSite* site; + + WasmBreakpointSiteMap::AddPtr p = breakpointSites_.lookupForAdd(offset); + if (!p) { + site = cx->new_<WasmBreakpointSite>(instance->object(), offset); + if (!site) { + return nullptr; + } + + if (!breakpointSites_.add(p, offset, site)) { + js_delete(site); + ReportOutOfMemory(cx); + return nullptr; + } + + AddCellMemory(instance->object(), sizeof(WasmBreakpointSite), + MemoryUse::BreakpointSite); + + toggleBreakpointTrap(cx->runtime(), offset, true); + } else { + site = p->value(); + } + return site; +} + +bool DebugState::hasBreakpointSite(uint32_t offset) { + return breakpointSites_.has(offset); +} + +void DebugState::destroyBreakpointSite(JSFreeOp* fop, Instance* instance, + uint32_t offset) { + WasmBreakpointSiteMap::Ptr p = breakpointSites_.lookup(offset); + MOZ_ASSERT(p); + fop->delete_(instance->objectUnbarriered(), p->value(), + MemoryUse::BreakpointSite); + breakpointSites_.remove(p); + toggleBreakpointTrap(fop->runtime(), offset, false); +} + +void DebugState::clearBreakpointsIn(JSFreeOp* fop, WasmInstanceObject* instance, + js::Debugger* dbg, JSObject* handler) { + MOZ_ASSERT(instance); + + // Breakpoints hold wrappers in the instance's compartment for the handler. + // Make sure we don't try to search for the unwrapped handler. + MOZ_ASSERT_IF(handler, instance->compartment() == handler->compartment()); + + if (breakpointSites_.empty()) { + return; + } + for (WasmBreakpointSiteMap::Enum e(breakpointSites_); !e.empty(); + e.popFront()) { + WasmBreakpointSite* site = e.front().value(); + MOZ_ASSERT(site->instanceObject == instance); + + Breakpoint* nextbp; + for (Breakpoint* bp = site->firstBreakpoint(); bp; bp = nextbp) { + nextbp = bp->nextInSite(); + MOZ_ASSERT(bp->site == site); + if ((!dbg || bp->debugger == dbg) && + (!handler || bp->getHandler() == handler)) { + bp->delete_(fop); + } + } + if (site->isEmpty()) { + fop->delete_(instance, site, MemoryUse::BreakpointSite); + e.removeFront(); + } + } +} + +void DebugState::toggleDebugTrap(uint32_t offset, bool enabled) { + MOZ_ASSERT(offset); + uint8_t* trap = code_->segment(Tier::Debug).base() + offset; + const Uint32Vector& farJumpOffsets = + metadata(Tier::Debug).debugTrapFarJumpOffsets; + if (enabled) { + MOZ_ASSERT(farJumpOffsets.length() > 0); + size_t i = 0; + while (i < farJumpOffsets.length() && offset < farJumpOffsets[i]) { + i++; + } + if (i >= farJumpOffsets.length() || + (i > 0 && offset - farJumpOffsets[i - 1] < farJumpOffsets[i] - offset)) + i--; + uint8_t* farJump = code_->segment(Tier::Debug).base() + farJumpOffsets[i]; + MacroAssembler::patchNopToCall(trap, farJump); + } else { + MacroAssembler::patchCallToNop(trap); + } +} + +void DebugState::adjustEnterAndLeaveFrameTrapsState(JSContext* cx, + bool enabled) { + MOZ_ASSERT_IF(!enabled, enterAndLeaveFrameTrapsCounter_ > 0); + + bool wasEnabled = enterAndLeaveFrameTrapsCounter_ > 0; + if (enabled) { + ++enterAndLeaveFrameTrapsCounter_; + } else { + --enterAndLeaveFrameTrapsCounter_; + } + bool stillEnabled = enterAndLeaveFrameTrapsCounter_ > 0; + if (wasEnabled == stillEnabled) { + return; + } + + const ModuleSegment& codeSegment = code_->segment(Tier::Debug); + AutoWritableJitCode awjc(cx->runtime(), codeSegment.base(), + codeSegment.length()); + for (const CallSite& callSite : callSites(Tier::Debug)) { + if (callSite.kind() != CallSite::EnterFrame && + callSite.kind() != CallSite::LeaveFrame) { + continue; + } + toggleDebugTrap(callSite.returnAddressOffset(), stillEnabled); + } +} + +void DebugState::ensureEnterFrameTrapsState(JSContext* cx, bool enabled) { + if (enterFrameTrapsEnabled_ == enabled) { + return; + } + + adjustEnterAndLeaveFrameTrapsState(cx, enabled); + + enterFrameTrapsEnabled_ = enabled; +} + +bool DebugState::debugGetLocalTypes(uint32_t funcIndex, ValTypeVector* locals, + size_t* argsLength, + StackResults* stackResults) { + const ValTypeVector& args = metadata().debugFuncArgTypes[funcIndex]; + const ValTypeVector& results = metadata().debugFuncReturnTypes[funcIndex]; + ResultType resultType(ResultType::Vector(results)); + *argsLength = args.length(); + *stackResults = ABIResultIter::HasStackResults(resultType) + ? StackResults::HasStackResults + : StackResults::NoStackResults; + if (!locals->appendAll(args)) { + return false; + } + + // Decode local var types from wasm binary function body. + const CodeRange& range = + codeRanges(Tier::Debug)[funcToCodeRangeIndex(funcIndex)]; + // In wasm, the Code points to the function start via funcLineOrBytecode. + size_t offsetInModule = range.funcLineOrBytecode(); + Decoder d(bytecode().begin() + offsetInModule, bytecode().end(), + offsetInModule, + /* error = */ nullptr); + return DecodeValidatedLocalEntries(d, locals); +} + +bool DebugState::getGlobal(Instance& instance, uint32_t globalIndex, + MutableHandleValue vp) { + const GlobalDesc& global = metadata().globals[globalIndex]; + + if (global.isConstant()) { + LitVal value = global.constantValue(); + switch (value.type().kind()) { + case ValType::I32: + vp.set(Int32Value(value.i32())); + break; + case ValType::I64: + // Just display as a Number; it's ok if we lose some precision + vp.set(NumberValue((double)value.i64())); + break; + case ValType::F32: + vp.set(NumberValue(JS::CanonicalizeNaN(value.f32()))); + break; + case ValType::F64: + vp.set(NumberValue(JS::CanonicalizeNaN(value.f64()))); + break; + case ValType::Ref: + // It's possible to do better. We could try some kind of hashing + // scheme, to make the pointer recognizable without revealing it. + vp.set(MagicValue(JS_OPTIMIZED_OUT)); + break; + case ValType::V128: + // Debugger must be updated to handle this, and should be updated to + // handle i64 in any case. + vp.set(MagicValue(JS_OPTIMIZED_OUT)); + break; + default: + MOZ_CRASH("Global constant type"); + } + return true; + } + + uint8_t* globalData = instance.globalData(); + void* dataPtr = globalData + global.offset(); + if (global.isIndirect()) { + dataPtr = *static_cast<void**>(dataPtr); + } + switch (global.type().kind()) { + case ValType::I32: { + vp.set(Int32Value(*static_cast<int32_t*>(dataPtr))); + break; + } + case ValType::I64: { + // Just display as a Number; it's ok if we lose some precision + vp.set(NumberValue((double)*static_cast<int64_t*>(dataPtr))); + break; + } + case ValType::F32: { + vp.set(NumberValue(JS::CanonicalizeNaN(*static_cast<float*>(dataPtr)))); + break; + } + case ValType::F64: { + vp.set(NumberValue(JS::CanonicalizeNaN(*static_cast<double*>(dataPtr)))); + break; + } + case ValType::Ref: { + // Just hide it. See above. + vp.set(MagicValue(JS_OPTIMIZED_OUT)); + break; + } + case ValType::V128: { + // Just hide it. See above. + vp.set(MagicValue(JS_OPTIMIZED_OUT)); + break; + } + default: { + MOZ_CRASH("Global variable type"); + break; + } + } + return true; +} + +bool DebugState::getSourceMappingURL(JSContext* cx, + MutableHandleString result) const { + result.set(nullptr); + + for (const CustomSection& customSection : module_->customSections()) { + const Bytes& sectionName = customSection.name; + if (strlen(SourceMappingURLSectionName) != sectionName.length() || + memcmp(SourceMappingURLSectionName, sectionName.begin(), + sectionName.length()) != 0) { + continue; + } + + // Parse found "SourceMappingURL" custom section. + Decoder d(customSection.payload->begin(), customSection.payload->end(), 0, + /* error = */ nullptr); + uint32_t nchars; + if (!d.readVarU32(&nchars)) { + return true; // ignoring invalid section data + } + const uint8_t* chars; + if (!d.readBytes(nchars, &chars) || d.currentPosition() != d.end()) { + return true; // ignoring invalid section data + } + + JS::UTF8Chars utf8Chars(reinterpret_cast<const char*>(chars), nchars); + JSString* str = JS_NewStringCopyUTF8N(cx, utf8Chars); + if (!str) { + return false; + } + result.set(str); + return true; + } + + // Check presence of "SourceMap:" HTTP response header. + char* sourceMapURL = metadata().sourceMapURL.get(); + if (sourceMapURL && strlen(sourceMapURL)) { + JS::UTF8Chars utf8Chars(sourceMapURL, strlen(sourceMapURL)); + JSString* str = JS_NewStringCopyUTF8N(cx, utf8Chars); + if (!str) { + return false; + } + result.set(str); + } + return true; +} + +void DebugState::addSizeOfMisc(MallocSizeOf mallocSizeOf, + Metadata::SeenSet* seenMetadata, + Code::SeenSet* seenCode, size_t* code, + size_t* data) const { + code_->addSizeOfMiscIfNotSeen(mallocSizeOf, seenMetadata, seenCode, code, + data); + module_->addSizeOfMisc(mallocSizeOf, seenMetadata, seenCode, code, data); +} |