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/* -*- 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
#ifndef jit_JitFrames_h
#define jit_JitFrames_h
#include "mozilla/Assertions.h"
#include <stddef.h>
#include <stdint.h>
#include "jit/CalleeToken.h"
#include "jit/MachineState.h"
#include "jit/Registers.h"
#include "js/Id.h"
#include "js/TypeDecls.h"
#include "js/Value.h"
namespace js {
namespace wasm {
class Instance;
}
namespace jit {
enum class FrameType;
enum class VMFunctionId;
class IonScript;
class JitActivation;
class JitFrameLayout;
struct SafepointSlotEntry;
struct VMFunctionData;
// [SMDOC] JIT Frame Layout
//
// Frame Headers:
//
// In between every two frames lies a small header describing both frames. This
// header, minimally, contains a returnAddress word and a descriptor word (See
// CommonFrameLayout). The descriptor describes the type of the older (caller)
// frame, whereas the returnAddress describes the address the newer (callee)
// frame will return to. For JitFrameLayout, the descriptor also stores the
// number of arguments passed from the caller to the callee frame.
//
// Special Frames:
//
// Two special frame types exist:
// - Entry frames begin a JitActivation, and therefore there is exactly one
// per activation of EnterJit or EnterBaseline. These reuse JitFrameLayout.
// - Exit frames are necessary to leave JIT code and enter C++, and thus,
// C++ code will always begin iterating from the topmost exit frame.
//
// Approximate Layout:
//
// The layout of an Ion frame on the C stack is roughly:
// argN _
// ... \ - These are jsvals
// arg0 /
// -3 this _/
// -2 callee
// -1 descriptor
// 0 returnAddress
// .. locals ..
// [SMDOC] Frame Descriptor Layout
//
// A frame descriptor word has the following data:
//
// high bits: [ numActualArgs |
// has-inlined-icscript bit |
// has-cached-saved-frame bit |
// low bits: frame type ]
//
// * numActualArgs: for JitFrameLayout, the number of arguments passed by the
// caller.
// * HasInlinedICScript: Set when passing a private ICScript to a trial-inlined
// script.
// * HasCachedSavedFrame: Used to power the LiveSavedFrameCache optimization.
// See the comment in Activation.h
// * Frame Type: BaselineJS, Exit, etc. (jit::FrameType)
//
class FrameDescriptor {
public:
static const uint32_t TypeBits = 4;
static const uint32_t TypeMask = (1 << TypeBits) - 1;
static const uint32_t HasCachedSavedFrame = 1 << TypeBits;
static const uint32_t HasInlinedICScript = 1 << (TypeBits + 1);
static const uint32_t NumActualArgsShift = TypeBits + 2;
explicit FrameDescriptor(FrameType type) : raw_(uint32_t(type)) {}
FrameDescriptor(FrameType type, uint32_t argc, bool hasInlined = false)
: raw_(argc << NumActualArgsShift | uint32_t(type)) {
if (hasInlined) {
setHasInlinedICScript();
}
MOZ_ASSERT(numActualArgs() == argc, "argc must fit in descriptor");
}
FrameType type() const { return FrameType(raw_ & TypeMask); }
void changeType(FrameType type) {
raw_ &= ~TypeMask;
raw_ |= uintptr_t(type);
}
uint32_t numActualArgs() const { return raw_ >> NumActualArgsShift; }
bool hasCachedSavedFrame() const { return raw_ & HasCachedSavedFrame; }
void setHasCachedSavedFrame() { raw_ |= HasCachedSavedFrame; }
void clearHasCachedSavedFrame() { raw_ &= ~HasCachedSavedFrame; }
bool hasInlinedICScript() const { return raw_ & HasInlinedICScript; }
void setHasInlinedICScript() { raw_ |= HasInlinedICScript; }
uint32_t value() const {
MOZ_ASSERT(raw_ == uint32_t(raw_));
return raw_;
}
private:
uintptr_t raw_;
};
static inline uint32_t MakeFrameDescriptor(FrameType type) {
FrameDescriptor descriptor(type);
return descriptor.value();
}
// For JitFrameLayout, the descriptor also stores the number of arguments passed
// by the caller. Note that |type| is the type of the *older* frame and |argc|
// is the number of arguments passed to the *newer* frame.
static inline uint32_t MakeFrameDescriptorForJitCall(FrameType type,
uint32_t argc) {
FrameDescriptor descriptor(type, argc);
return descriptor.value();
}
struct BaselineBailoutInfo;
enum class ExceptionResumeKind : int32_t {
// There is no exception handler in this activation.
// Return from the entry frame.
EntryFrame,
// The exception was caught in baseline.
// Restore state and jump to the catch block.
Catch,
// A finally block must be executed in baseline.
// Stash the exception on the stack and jump to the finally block.
Finally,
// We are forcing an early return with a specific return value.
// This is used by the debugger and when closing generators.
// Immediately return from the current frame with the given value.
ForcedReturnBaseline,
ForcedReturnIon,
// This frame is currently executing in Ion, but we must bail out
// to baseline before handling the exception.
// Jump to the bailout tail stub.
Bailout,
// Return to the wasm interpreter entry frame.
WasmInterpEntry,
// The exception was caught by a wasm catch handler.
// Restore state and jump to it.
WasmCatch
};
// Data needed to recover from an exception.
struct ResumeFromException {
uint8_t* framePointer;
uint8_t* stackPointer;
uint8_t* target;
ExceptionResumeKind kind;
wasm::Instance* instance;
// Value to push when resuming into a |finally| block.
// Also used by Wasm to send the exception object to the throw stub.
JS::Value exception;
// Exception stack to push when resuming into a |finally| block.
JS::Value exceptionStack;
BaselineBailoutInfo* bailoutInfo;
static size_t offsetOfFramePointer() {
return offsetof(ResumeFromException, framePointer);
}
static size_t offsetOfStackPointer() {
return offsetof(ResumeFromException, stackPointer);
}
static size_t offsetOfTarget() {
return offsetof(ResumeFromException, target);
}
static size_t offsetOfKind() { return offsetof(ResumeFromException, kind); }
static size_t offsetOfInstance() {
return offsetof(ResumeFromException, instance);
}
static size_t offsetOfException() {
return offsetof(ResumeFromException, exception);
}
static size_t offsetOfExceptionStack() {
return offsetof(ResumeFromException, exceptionStack);
}
static size_t offsetOfBailoutInfo() {
return offsetof(ResumeFromException, bailoutInfo);
}
};
#if defined(JS_CODEGEN_ARM64)
static_assert(sizeof(ResumeFromException) % 16 == 0,
"ResumeFromException should be aligned");
#endif
void HandleException(ResumeFromException* rfe);
void EnsureUnwoundJitExitFrame(JitActivation* act, JitFrameLayout* frame);
void TraceJitActivations(JSContext* cx, JSTracer* trc);
// Trace weak pointers in baseline stubs in activations for zones that are
// currently being swept.
void TraceWeakJitActivationsInSweepingZones(JSContext* cx, JSTracer* trc);
void UpdateJitActivationsForMinorGC(JSRuntime* rt);
void UpdateJitActivationsForCompactingGC(JSRuntime* rt);
// Returns the JSScript associated with the topmost JIT frame.
JSScript* GetTopJitJSScript(JSContext* cx);
#if defined(JS_CODEGEN_ARM64)
uint8_t* alignDoubleSpill(uint8_t* pointer);
#else
inline uint8_t* alignDoubleSpill(uint8_t* pointer) {
// This is a no-op on most platforms.
return pointer;
}
#endif
// Layout of the frame prefix. This assumes the stack architecture grows down.
// If this is ever not the case, we'll have to refactor.
class CommonFrameLayout {
uint8_t* callerFramePtr_;
uint8_t* returnAddress_;
FrameDescriptor descriptor_;
public:
static constexpr size_t offsetOfDescriptor() {
return offsetof(CommonFrameLayout, descriptor_);
}
FrameDescriptor descriptor() const { return descriptor_; }
static constexpr size_t offsetOfReturnAddress() {
return offsetof(CommonFrameLayout, returnAddress_);
}
FrameType prevType() const { return descriptor_.type(); }
void changePrevType(FrameType type) { descriptor_.changeType(type); }
bool hasCachedSavedFrame() const { return descriptor_.hasCachedSavedFrame(); }
void setHasCachedSavedFrame() { descriptor_.setHasCachedSavedFrame(); }
void clearHasCachedSavedFrame() { descriptor_.clearHasCachedSavedFrame(); }
uint8_t* returnAddress() const { return returnAddress_; }
void setReturnAddress(uint8_t* addr) { returnAddress_ = addr; }
uint8_t* callerFramePtr() const { return callerFramePtr_; }
static constexpr size_t offsetOfCallerFramePtr() {
return offsetof(CommonFrameLayout, callerFramePtr_);
}
static constexpr size_t bytesPoppedAfterCall() {
// The return address and frame pointer are popped by the callee/call.
return 2 * sizeof(void*);
}
};
class JitFrameLayout : public CommonFrameLayout {
CalleeToken calleeToken_;
public:
CalleeToken calleeToken() const { return calleeToken_; }
void replaceCalleeToken(CalleeToken calleeToken) {
calleeToken_ = calleeToken;
}
static constexpr size_t offsetOfCalleeToken() {
return offsetof(JitFrameLayout, calleeToken_);
}
static constexpr size_t offsetOfThis() { return sizeof(JitFrameLayout); }
static constexpr size_t offsetOfActualArgs() {
return offsetOfThis() + sizeof(JS::Value);
}
static constexpr size_t offsetOfActualArg(size_t arg) {
return offsetOfActualArgs() + arg * sizeof(JS::Value);
}
JS::Value& thisv() {
MOZ_ASSERT(CalleeTokenIsFunction(calleeToken()));
return thisAndActualArgs()[0];
}
JS::Value* thisAndActualArgs() {
MOZ_ASSERT(CalleeTokenIsFunction(calleeToken()));
return (JS::Value*)(this + 1);
}
JS::Value* actualArgs() { return thisAndActualArgs() + 1; }
uintptr_t numActualArgs() const { return descriptor().numActualArgs(); }
// Computes a reference to a stack or argument slot, where a slot is a
// distance from the base frame pointer, as would be used for LStackSlot
// or LArgument.
uintptr_t* slotRef(SafepointSlotEntry where);
static inline size_t Size() { return sizeof(JitFrameLayout); }
};
class BaselineInterpreterEntryFrameLayout : public JitFrameLayout {
public:
static inline size_t Size() {
return sizeof(BaselineInterpreterEntryFrameLayout);
}
};
class RectifierFrameLayout : public JitFrameLayout {
public:
static inline size_t Size() { return sizeof(RectifierFrameLayout); }
};
class TrampolineNativeFrameLayout : public JitFrameLayout {
public:
static inline size_t Size() { return sizeof(TrampolineNativeFrameLayout); }
template <typename T>
T* getFrameData() {
uint8_t* raw = reinterpret_cast<uint8_t*>(this) - sizeof(T);
return reinterpret_cast<T*>(raw);
}
};
class WasmToJSJitFrameLayout : public JitFrameLayout {
public:
static inline size_t Size() { return sizeof(WasmToJSJitFrameLayout); }
};
class IonICCallFrameLayout : public CommonFrameLayout {
protected:
// Pointer to root the stub's JitCode.
JitCode* stubCode_;
public:
static constexpr size_t LocallyTracedValueOffset = sizeof(void*);
JitCode** stubCode() { return &stubCode_; }
static size_t Size() { return sizeof(IonICCallFrameLayout); }
inline Value* locallyTracedValuePtr(size_t index) {
uint8_t* fp = reinterpret_cast<uint8_t*>(this);
return reinterpret_cast<Value*>(fp - LocallyTracedValueOffset -
index * sizeof(Value));
}
};
enum class ExitFrameType : uint8_t {
CallNative = 0x0,
ConstructNative = 0x1,
IonDOMGetter = 0x2,
IonDOMSetter = 0x3,
IonDOMMethod = 0x4,
IonOOLNative = 0x5,
IonOOLProxy = 0x6,
WasmGenericJitEntry = 0x7,
DirectWasmJitCall = 0x8,
UnwoundJit = 0x9,
InterpreterStub = 0xA,
LazyLink = 0xB,
Bare = 0xC,
// This must be the last value in this enum. See ExitFooterFrame::data_.
VMFunction = 0xD
};
// GC related data used to keep alive data surrounding the Exit frame.
class ExitFooterFrame {
// Stores either the ExitFrameType or, for a VMFunction call,
// `ExitFrameType::VMFunction + VMFunctionId`.
uintptr_t data_;
#ifdef DEBUG
void assertValidVMFunctionId() const;
#else
void assertValidVMFunctionId() const {}
#endif
public:
static constexpr size_t Size() { return sizeof(ExitFooterFrame); }
void setUnwoundJitExitFrame() {
data_ = uintptr_t(ExitFrameType::UnwoundJit);
}
ExitFrameType type() const {
if (data_ >= uintptr_t(ExitFrameType::VMFunction)) {
return ExitFrameType::VMFunction;
}
return ExitFrameType(data_);
}
VMFunctionId functionId() const {
MOZ_ASSERT(type() == ExitFrameType::VMFunction);
assertValidVMFunctionId();
return static_cast<VMFunctionId>(data_ - size_t(ExitFrameType::VMFunction));
}
// This should only be called for function()->outParam == Type_Handle
template <typename T>
T* outParam() {
uint8_t* address = reinterpret_cast<uint8_t*>(this);
return reinterpret_cast<T*>(address - sizeof(T));
}
};
class NativeExitFrameLayout;
class IonOOLNativeExitFrameLayout;
class IonOOLProxyExitFrameLayout;
class IonDOMExitFrameLayout;
// this is the frame layout when we are exiting ion code, and about to enter
// platform ABI code
class ExitFrameLayout : public CommonFrameLayout {
inline uint8_t* top() { return reinterpret_cast<uint8_t*>(this + 1); }
public:
static constexpr size_t Size() { return sizeof(ExitFrameLayout); }
static constexpr size_t SizeWithFooter() {
return Size() + ExitFooterFrame::Size();
}
inline ExitFooterFrame* footer() {
uint8_t* sp = reinterpret_cast<uint8_t*>(this);
return reinterpret_cast<ExitFooterFrame*>(sp - ExitFooterFrame::Size());
}
// argBase targets the point which precedes the exit frame. Arguments of VM
// each wrapper are pushed before the exit frame. This correspond exactly
// to the value of the argBase register of the generateVMWrapper function.
inline uint8_t* argBase() {
MOZ_ASSERT(isWrapperExit());
return top();
}
inline bool isWrapperExit() {
return footer()->type() == ExitFrameType::VMFunction;
}
inline bool isBareExit() { return footer()->type() == ExitFrameType::Bare; }
inline bool isUnwoundJitExit() {
return footer()->type() == ExitFrameType::UnwoundJit;
}
// See the various exit frame layouts below.
template <typename T>
inline bool is() {
return footer()->type() == T::Type();
}
template <typename T>
inline T* as() {
MOZ_ASSERT(this->is<T>());
return reinterpret_cast<T*>(footer());
}
};
// Cannot inherit implementation since we need to extend the top of
// ExitFrameLayout.
class NativeExitFrameLayout {
protected: // only to silence a clang warning about unused private fields
ExitFooterFrame footer_;
ExitFrameLayout exit_;
uintptr_t argc_;
// We need to split the Value into 2 fields of 32 bits, otherwise the C++
// compiler may add some padding between the fields.
uint32_t loCalleeResult_;
uint32_t hiCalleeResult_;
public:
static inline size_t Size() { return sizeof(NativeExitFrameLayout); }
static size_t offsetOfResult() {
return offsetof(NativeExitFrameLayout, loCalleeResult_);
}
inline JS::Value* vp() {
return reinterpret_cast<JS::Value*>(&loCalleeResult_);
}
inline uintptr_t argc() const { return argc_; }
};
class CallNativeExitFrameLayout : public NativeExitFrameLayout {
public:
static ExitFrameType Type() { return ExitFrameType::CallNative; }
};
class ConstructNativeExitFrameLayout : public NativeExitFrameLayout {
public:
static ExitFrameType Type() { return ExitFrameType::ConstructNative; }
};
template <>
inline bool ExitFrameLayout::is<NativeExitFrameLayout>() {
return is<CallNativeExitFrameLayout>() ||
is<ConstructNativeExitFrameLayout>();
}
class IonOOLNativeExitFrameLayout {
protected: // only to silence a clang warning about unused private fields
ExitFooterFrame footer_;
ExitFrameLayout exit_;
// pointer to root the stub's JitCode
JitCode* stubCode_;
uintptr_t argc_;
// We need to split the Value into 2 fields of 32 bits, otherwise the C++
// compiler may add some padding between the fields.
uint32_t loCalleeResult_;
uint32_t hiCalleeResult_;
// Split Value for |this| and args above.
uint32_t loThis_;
uint32_t hiThis_;
public:
static ExitFrameType Type() { return ExitFrameType::IonOOLNative; }
static inline size_t Size(size_t argc) {
// The frame accounts for the callee/result and |this|, so we only need
// args.
return sizeof(IonOOLNativeExitFrameLayout) + (argc * sizeof(JS::Value));
}
static size_t offsetOfResult() {
return offsetof(IonOOLNativeExitFrameLayout, loCalleeResult_);
}
inline JitCode** stubCode() { return &stubCode_; }
inline JS::Value* vp() {
return reinterpret_cast<JS::Value*>(&loCalleeResult_);
}
inline JS::Value* thisp() { return reinterpret_cast<JS::Value*>(&loThis_); }
inline uintptr_t argc() const { return argc_; }
};
// ProxyGetProperty(JSContext* cx, HandleObject proxy, HandleId id,
// MutableHandleValue vp)
// ProxyCallProperty(JSContext* cx, HandleObject proxy, HandleId id,
// MutableHandleValue vp)
// ProxySetProperty(JSContext* cx, HandleObject proxy, HandleId id,
// MutableHandleValue vp, bool strict)
class IonOOLProxyExitFrameLayout {
protected: // only to silence a clang warning about unused private fields
ExitFooterFrame footer_;
ExitFrameLayout exit_;
// The proxy object.
JSObject* proxy_;
// id for HandleId
jsid id_;
// space for MutableHandleValue result
// use two uint32_t so compiler doesn't align.
uint32_t vp0_;
uint32_t vp1_;
// pointer to root the stub's JitCode
JitCode* stubCode_;
public:
static ExitFrameType Type() { return ExitFrameType::IonOOLProxy; }
static inline size_t Size() { return sizeof(IonOOLProxyExitFrameLayout); }
static size_t offsetOfResult() {
return offsetof(IonOOLProxyExitFrameLayout, vp0_);
}
inline JitCode** stubCode() { return &stubCode_; }
inline JS::Value* vp() { return reinterpret_cast<JS::Value*>(&vp0_); }
inline jsid* id() { return &id_; }
inline JSObject** proxy() { return &proxy_; }
};
class IonDOMExitFrameLayout {
protected: // only to silence a clang warning about unused private fields
ExitFooterFrame footer_;
ExitFrameLayout exit_;
JSObject* thisObj;
// We need to split the Value into 2 fields of 32 bits, otherwise the C++
// compiler may add some padding between the fields.
uint32_t loCalleeResult_;
uint32_t hiCalleeResult_;
public:
static ExitFrameType GetterType() { return ExitFrameType::IonDOMGetter; }
static ExitFrameType SetterType() { return ExitFrameType::IonDOMSetter; }
static inline size_t Size() { return sizeof(IonDOMExitFrameLayout); }
static size_t offsetOfResult() {
return offsetof(IonDOMExitFrameLayout, loCalleeResult_);
}
inline JS::Value* vp() {
return reinterpret_cast<JS::Value*>(&loCalleeResult_);
}
inline JSObject** thisObjAddress() { return &thisObj; }
inline bool isMethodFrame();
};
struct IonDOMMethodExitFrameLayoutTraits;
class IonDOMMethodExitFrameLayout {
protected: // only to silence a clang warning about unused private fields
ExitFooterFrame footer_;
ExitFrameLayout exit_;
// This must be the last thing pushed, so as to stay common with
// IonDOMExitFrameLayout.
JSObject* thisObj_;
JS::Value* argv_;
uintptr_t argc_;
// We need to split the Value into 2 fields of 32 bits, otherwise the C++
// compiler may add some padding between the fields.
uint32_t loCalleeResult_;
uint32_t hiCalleeResult_;
friend struct IonDOMMethodExitFrameLayoutTraits;
public:
static ExitFrameType Type() { return ExitFrameType::IonDOMMethod; }
static inline size_t Size() { return sizeof(IonDOMMethodExitFrameLayout); }
static size_t offsetOfResult() {
return offsetof(IonDOMMethodExitFrameLayout, loCalleeResult_);
}
inline JS::Value* vp() {
// The code in visitCallDOMNative depends on this static assert holding
static_assert(
offsetof(IonDOMMethodExitFrameLayout, loCalleeResult_) ==
(offsetof(IonDOMMethodExitFrameLayout, argc_) + sizeof(uintptr_t)));
return reinterpret_cast<JS::Value*>(&loCalleeResult_);
}
inline JSObject** thisObjAddress() { return &thisObj_; }
inline uintptr_t argc() { return argc_; }
};
inline bool IonDOMExitFrameLayout::isMethodFrame() {
return footer_.type() == IonDOMMethodExitFrameLayout::Type();
}
template <>
inline bool ExitFrameLayout::is<IonDOMExitFrameLayout>() {
ExitFrameType type = footer()->type();
return type == IonDOMExitFrameLayout::GetterType() ||
type == IonDOMExitFrameLayout::SetterType() ||
type == IonDOMMethodExitFrameLayout::Type();
}
template <>
inline IonDOMExitFrameLayout* ExitFrameLayout::as<IonDOMExitFrameLayout>() {
MOZ_ASSERT(is<IonDOMExitFrameLayout>());
return reinterpret_cast<IonDOMExitFrameLayout*>(footer());
}
struct IonDOMMethodExitFrameLayoutTraits {
static const size_t offsetOfArgcFromArgv =
offsetof(IonDOMMethodExitFrameLayout, argc_) -
offsetof(IonDOMMethodExitFrameLayout, argv_);
};
// Cannot inherit implementation since we need to extend the top of
// ExitFrameLayout.
class CalledFromJitExitFrameLayout {
protected: // silence clang warning about unused private fields
ExitFooterFrame footer_;
JitFrameLayout exit_;
public:
static inline size_t Size() { return sizeof(CalledFromJitExitFrameLayout); }
inline JitFrameLayout* jsFrame() { return &exit_; }
static size_t offsetOfExitFrame() {
return offsetof(CalledFromJitExitFrameLayout, exit_);
}
};
class LazyLinkExitFrameLayout : public CalledFromJitExitFrameLayout {
public:
static ExitFrameType Type() { return ExitFrameType::LazyLink; }
};
class InterpreterStubExitFrameLayout : public CalledFromJitExitFrameLayout {
public:
static ExitFrameType Type() { return ExitFrameType::InterpreterStub; }
};
class WasmGenericJitEntryFrameLayout : CalledFromJitExitFrameLayout {
public:
static ExitFrameType Type() { return ExitFrameType::WasmGenericJitEntry; }
};
template <>
inline bool ExitFrameLayout::is<CalledFromJitExitFrameLayout>() {
return is<InterpreterStubExitFrameLayout>() ||
is<LazyLinkExitFrameLayout>() || is<WasmGenericJitEntryFrameLayout>();
}
template <>
inline CalledFromJitExitFrameLayout*
ExitFrameLayout::as<CalledFromJitExitFrameLayout>() {
MOZ_ASSERT(is<CalledFromJitExitFrameLayout>());
uint8_t* sp = reinterpret_cast<uint8_t*>(this);
sp -= CalledFromJitExitFrameLayout::offsetOfExitFrame();
return reinterpret_cast<CalledFromJitExitFrameLayout*>(sp);
}
class DirectWasmJitCallFrameLayout {
protected: // silence clang warning about unused private fields
ExitFooterFrame footer_;
ExitFrameLayout exit_;
public:
static ExitFrameType Type() { return ExitFrameType::DirectWasmJitCall; }
};
class ICStub;
class BaselineStubFrameLayout : public CommonFrameLayout {
// Info on the stack
//
// +-------------------------------------------+
// |BaselineStubFrameLayout |
// +-------------------------------------------+
// | - Descriptor | <= Marks end of
// | - Return address | FrameType::BaselineJS
// | - CallerFramePtr | <= Frame pointer points here
// +-------------------------------------------+
// | - StubPtr | <= Technically these fields
// | - InlinedICScript or LocallyTracedValue | precede the FrameLayout in
// | LocallyTracedValue...| memory.
// +-------------------------------------------+
//
// StubPtr is always present (but can be null; see generateDebugTrapHandler).
// InlinedICScript is only present if the HasInlinedICScript flag is set in
// the callee's frame descriptor (not shown in this diagram). Alternatively,
// we support up to 255 locally traced values (with the count stored in
// stub->jitCode()->localTracingSlots()).
public:
static constexpr size_t ICStubOffset = sizeof(void*);
static constexpr int ICStubOffsetFromFP = -int(ICStubOffset);
static constexpr int InlinedICScriptOffsetFromFP = 2 * -int(sizeof(void*));
static constexpr size_t LocallyTracedValueOffset = 2 * sizeof(void*);
static inline size_t Size() { return sizeof(BaselineStubFrameLayout); }
ICStub* maybeStubPtr() {
uint8_t* fp = reinterpret_cast<uint8_t*>(this);
return *reinterpret_cast<ICStub**>(fp - ICStubOffset);
}
void setStubPtr(ICStub* stub) {
MOZ_ASSERT(stub);
uint8_t* fp = reinterpret_cast<uint8_t*>(this);
*reinterpret_cast<ICStub**>(fp - ICStubOffset) = stub;
}
inline Value* locallyTracedValuePtr(size_t index) {
uint8_t* fp = reinterpret_cast<uint8_t*>(this);
return reinterpret_cast<Value*>(fp - LocallyTracedValueOffset -
index * sizeof(Value));
}
};
// An invalidation bailout stack is at the stack pointer for the callee frame.
class InvalidationBailoutStack {
RegisterDump::FPUArray fpregs_;
RegisterDump::GPRArray regs_;
IonScript* ionScript_;
uint8_t* osiPointReturnAddress_;
public:
uint8_t* sp() const {
return (uint8_t*)this + sizeof(InvalidationBailoutStack);
}
JitFrameLayout* fp() const;
MachineState machine() { return MachineState::FromBailout(regs_, fpregs_); }
IonScript* ionScript() const { return ionScript_; }
uint8_t* osiPointReturnAddress() const { return osiPointReturnAddress_; }
static size_t offsetOfFpRegs() {
return offsetof(InvalidationBailoutStack, fpregs_);
}
static size_t offsetOfRegs() {
return offsetof(InvalidationBailoutStack, regs_);
}
void checkInvariants() const;
};
// Baseline requires one slot for this/argument type checks.
static const uint32_t MinJITStackSize = 1;
} /* namespace jit */
} /* namespace js */
#endif /* jit_JitFrames_h */