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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef jit_BaselineDebugModeOSR_h
#define jit_BaselineDebugModeOSR_h
#include "jit/BaselineFrame.h"
#include "jit/BaselineIC.h"
#include "jit/BaselineJIT.h"
#include "jit/JitFrameIterator.h"
#include "vm/Debugger.h"
namespace js {
namespace jit {
// Note that this file and the corresponding .cpp implement debug mode
// on-stack recompilation. This is to be distinguished from ordinary
// Baseline->Ion OSR, which is used to jump into compiled loops.
//
// A volatile location due to recompilation of an on-stack baseline script
// (e.g., for debug mode toggling).
//
// It is usually used in fallback stubs which may trigger on-stack
// recompilation by calling out into the VM. Example use:
//
// DebugModeOSRVolatileStub<FallbackStubT*> stub(frame, stub_)
//
// // Call out to the VM
// // Other effectful operations like TypeScript::Monitor
//
// if (stub.invalid())
// return true;
//
// // First use of stub after VM call.
//
template <typename T>
class DebugModeOSRVolatileStub
{
ICStubCompiler::Engine engine_;
T stub_;
BaselineFrame* frame_;
uint32_t pcOffset_;
public:
DebugModeOSRVolatileStub(ICStubCompiler::Engine engine, BaselineFrame* frame,
ICFallbackStub* stub)
: engine_(engine),
stub_(static_cast<T>(stub)),
frame_(frame),
pcOffset_(stub->icEntry()->pcOffset())
{ }
DebugModeOSRVolatileStub(BaselineFrame* frame, ICFallbackStub* stub)
: engine_(ICStubCompiler::Engine::Baseline),
stub_(static_cast<T>(stub)),
frame_(frame),
pcOffset_(stub->icEntry()->pcOffset())
{ }
bool invalid() const {
if (engine_ == ICStubCompiler::Engine::IonMonkey)
return stub_->invalid();
MOZ_ASSERT(!frame_->isHandlingException());
ICEntry& entry = frame_->script()->baselineScript()->icEntryFromPCOffset(pcOffset_);
return stub_ != entry.fallbackStub();
}
operator const T&() const { MOZ_ASSERT(!invalid()); return stub_; }
T operator->() const { MOZ_ASSERT(!invalid()); return stub_; }
T* address() { MOZ_ASSERT(!invalid()); return &stub_; }
const T* address() const { MOZ_ASSERT(!invalid()); return &stub_; }
T& get() { MOZ_ASSERT(!invalid()); return stub_; }
const T& get() const { MOZ_ASSERT(!invalid()); return stub_; }
bool operator!=(const T& other) const { MOZ_ASSERT(!invalid()); return stub_ != other; }
bool operator==(const T& other) const { MOZ_ASSERT(!invalid()); return stub_ == other; }
};
//
// A JitFrameIterator that updates itself in case of recompilation of an
// on-stack baseline script.
//
class DebugModeOSRVolatileJitFrameIterator : public JitFrameIterator
{
DebugModeOSRVolatileJitFrameIterator** stack;
DebugModeOSRVolatileJitFrameIterator* prev;
public:
explicit DebugModeOSRVolatileJitFrameIterator(JSContext* cx)
: JitFrameIterator(cx)
{
stack = &cx->liveVolatileJitFrameIterators_;
prev = *stack;
*stack = this;
}
~DebugModeOSRVolatileJitFrameIterator() {
MOZ_ASSERT(*stack == this);
*stack = prev;
}
static void forwardLiveIterators(JSContext* cx, uint8_t* oldAddr, uint8_t* newAddr);
};
//
// Auxiliary info to help the DebugModeOSRHandler fix up state.
//
struct BaselineDebugModeOSRInfo
{
uint8_t* resumeAddr;
jsbytecode* pc;
PCMappingSlotInfo slotInfo;
ICEntry::Kind frameKind;
// Filled in by SyncBaselineDebugModeOSRInfo.
uintptr_t stackAdjust;
Value valueR0;
Value valueR1;
BaselineDebugModeOSRInfo(jsbytecode* pc, ICEntry::Kind kind)
: resumeAddr(nullptr),
pc(pc),
slotInfo(0),
frameKind(kind),
stackAdjust(0),
valueR0(UndefinedValue()),
valueR1(UndefinedValue())
{ }
void popValueInto(PCMappingSlotInfo::SlotLocation loc, Value* vp);
};
MOZ_MUST_USE bool
RecompileOnStackBaselineScriptsForDebugMode(JSContext* cx,
const Debugger::ExecutionObservableSet& obs,
Debugger::IsObserving observing);
} // namespace jit
} // namespace js
#endif // jit_BaselineDebugModeOSR_h
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