mozilla-central/js/src/vm/FrameIter.cpp (file symbol)

Source code

Revision control

Copy as Markdown

Other Tools

/* -*- 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 "vm/FrameIter-inl.h"
#include "mozilla/Assertions.h" // MOZ_ASSERT, MOZ_CRASH
#include "mozilla/MaybeOneOf.h" // mozilla::MaybeOneOf
#include <stddef.h> // size_t
#include <stdint.h> // uint8_t, uint32_t
#include <stdlib.h> // getenv
#include "jit/BaselineFrame.h" // js::jit::BaselineFrame
#include "jit/JitFrames.h" // js::jit::EnsureUnwoundJitExitFrame
#include "jit/JSJitFrameIter.h" // js::jit::{FrameType,InlineFrameIterator,JSJitFrameIter,MaybeReadFallback,SnapshotIterator}
#include "js/ColumnNumber.h" // JS::LimitedColumnNumberOneOrigin, JS::TaggedColumnNumberOneOrigin
#include "js/GCAPI.h" // JS::AutoSuppressGCAnalysis
#include "js/Principals.h" // JSSubsumesOp
#include "js/RootingAPI.h" // JS::Rooted
#include "vm/Activation.h" // js::Activation{,Iterator}
#include "vm/EnvironmentObject.h" // js::CallObject
#include "vm/JitActivation.h" // js::jit::JitActivation
#include "vm/JSContext.h" // JSContext
#include "vm/JSFunction.h" // JSFunction
#include "vm/JSScript.h" // js::PCToLineNumber, JSScript, js::ScriptSource
#include "vm/Runtime.h" // JSRuntime
#include "vm/Stack.h" // js::{AbstractFramePtr,InterpreterFrame,MaybeCheckAliasing}
#include "wasm/WasmFrameIter.h" // js::wasm::WasmFrameIter
#include "wasm/WasmInstance.h" // js::wasm::Instance
#include "jit/JSJitFrameIter-inl.h" // js::jit::JSJitFrameIter::baselineFrame{,NumValueSlots}
#include "vm/Stack-inl.h" // js::AbstractFramePtr::*
namespace JS {
class JS_PUBLIC_API Realm;
} // namespace JS
namespace js {
class ArgumentsObject;
} // namespace js
using JS::Realm;
using JS::Rooted;
using JS::Value;
using js::AbstractFramePtr;
using js::ArgumentsObject;
using js::CallObject;
using js::FrameIter;
using js::JitFrameIter;
using js::NonBuiltinFrameIter;
using js::NonBuiltinScriptFrameIter;
using js::OnlyJSJitFrameIter;
using js::ScriptSource;
using js::jit::JSJitFrameIter;
JitFrameIter::JitFrameIter(const JitFrameIter& another) { *this = another; }
JitFrameIter& JitFrameIter::operator=(const JitFrameIter& another) {
MOZ_ASSERT(this != &another);
act_ = another.act_;
mustUnwindActivation_ = another.mustUnwindActivation_;
if (isSome()) {
iter_.destroy();
}
if (!another.isSome()) {
return *this;
}
if (another.isJSJit()) {
iter_.construct<jit::JSJitFrameIter>(another.asJSJit());
} else {
MOZ_ASSERT(another.isWasm());
iter_.construct<wasm::WasmFrameIter>(another.asWasm());
}
return *this;
}
JitFrameIter::JitFrameIter(jit::JitActivation* act, bool mustUnwindActivation) {
act_ = act;
mustUnwindActivation_ = mustUnwindActivation;
MOZ_ASSERT(act->hasExitFP(),
"packedExitFP is used to determine if JSJit or wasm");
if (act->hasJSExitFP()) {
iter_.construct<jit::JSJitFrameIter>(act);
} else {
MOZ_ASSERT(act->hasWasmExitFP());
iter_.construct<wasm::WasmFrameIter>(act);
}
settle();
}
void JitFrameIter::skipNonScriptedJSFrames() {
if (isJSJit()) {
// Stop at the first scripted frame.
jit::JSJitFrameIter& frames = asJSJit();
while (!frames.isScripted() && !frames.done()) {
++frames;
}
settle();
}
}
bool JitFrameIter::isSelfHostedIgnoringInlining() const {
MOZ_ASSERT(!done());
if (isWasm()) {
return false;
}
return asJSJit().script()->selfHosted();
}
JS::Realm* JitFrameIter::realm() const {
MOZ_ASSERT(!done());
if (isWasm()) {
return asWasm().instance()->realm();
}
if (asJSJit().isScripted()) {
return asJSJit().script()->realm();
}
MOZ_RELEASE_ASSERT(asJSJit().isTrampolineNative());
return asJSJit().callee()->realm();
}
uint8_t* JitFrameIter::resumePCinCurrentFrame() const {
if (isWasm()) {
return asWasm().resumePCinCurrentFrame();
}
return asJSJit().resumePCinCurrentFrame();
}
bool JitFrameIter::done() const {
if (!isSome()) {
return true;
}
if (isJSJit()) {
return asJSJit().done();
}
if (isWasm()) {
return asWasm().done();
}
MOZ_CRASH("unhandled case");
}
void JitFrameIter::settle() {
if (isJSJit()) {
const jit::JSJitFrameIter& jitFrame = asJSJit();
if (jitFrame.type() != jit::FrameType::WasmToJSJit) {
return;
}
// Transition from js jit frames to wasm frames: we're on the
// wasm-to-jit fast path. The current stack layout is as follows:
// (stack grows downward)
//
// [--------------------]
// [WASM FUNC ]
// [WASM JIT EXIT FRAME ]
// [JIT WASM ENTRY FRAME] <-- we're here.
//
// So prevFP points to the wasm jit exit FP, maintaing the invariant in
// WasmFrameIter that the first frame is an exit frame and can be
// popped.
wasm::Frame* prevFP = (wasm::Frame*)jitFrame.prevFp();
if (mustUnwindActivation_) {
act_->setWasmExitFP(prevFP);
}
iter_.destroy();
iter_.construct<wasm::WasmFrameIter>(act_, prevFP);
MOZ_ASSERT(!asWasm().done());
return;
}
if (isWasm()) {
const wasm::WasmFrameIter& wasmFrame = asWasm();
if (!wasmFrame.hasUnwoundJitFrame()) {
return;
}
// Transition from wasm frames to jit frames: we're on the
// jit-to-wasm fast path. The current stack layout is as follows:
// (stack grows downward)
//
// [--------------------]
// [JIT FRAME ]
// [WASM JIT ENTRY FRAME] <-- we're here
//
// The wasm iterator has saved the previous jit frame pointer for us.
MOZ_ASSERT(wasmFrame.done());
uint8_t* prevFP = wasmFrame.unwoundCallerFP();
jit::FrameType prevFrameType = wasmFrame.unwoundJitFrameType();
if (mustUnwindActivation_) {
act_->setJSExitFP(prevFP);
}
iter_.destroy();
iter_.construct<jit::JSJitFrameIter>(act_, prevFrameType, prevFP);
MOZ_ASSERT(!asJSJit().done());
return;
}
}
void JitFrameIter::operator++() {
MOZ_ASSERT(isSome());
if (isJSJit()) {
const jit::JSJitFrameIter& jitFrame = asJSJit();
jit::JitFrameLayout* prevFrame = nullptr;
if (mustUnwindActivation_ && jitFrame.isScripted()) {
prevFrame = jitFrame.jsFrame();
}
++asJSJit();
if (prevFrame) {
// Unwind the frame by updating packedExitFP. This is necessary
// so that (1) debugger exception unwind and leave frame hooks
// don't see this frame when they use ScriptFrameIter, and (2)
// ScriptFrameIter does not crash when accessing an IonScript
// that's destroyed by the ionScript->decref call.
EnsureUnwoundJitExitFrame(act_, prevFrame);
}
} else if (isWasm()) {
++asWasm();
} else {
MOZ_CRASH("unhandled case");
}
settle();
}
OnlyJSJitFrameIter::OnlyJSJitFrameIter(jit::JitActivation* act)
: JitFrameIter(act) {
settle();
}
OnlyJSJitFrameIter::OnlyJSJitFrameIter(const ActivationIterator& iter)
: OnlyJSJitFrameIter(iter->asJit()) {}
/*****************************************************************************/
void FrameIter::popActivation() {
++data_.activations_;
settleOnActivation();
}
bool FrameIter::principalsSubsumeFrame() const {
// If the caller supplied principals, only show frames which are
// subsumed (of the same origin or of an origin accessible) by these
// principals.
MOZ_ASSERT(!done());
if (!data_.principals_) {
return true;
}
JSSubsumesOp subsumes = data_.cx_->runtime()->securityCallbacks->subsumes;
if (!subsumes) {
return true;
}
JS::AutoSuppressGCAnalysis nogc;
return subsumes(data_.principals_, realm()->principals());
}
void FrameIter::popInterpreterFrame() {
MOZ_ASSERT(data_.state_ == INTERP);
++data_.interpFrames_;
if (data_.interpFrames_.done()) {
popActivation();
} else {
data_.pc_ = data_.interpFrames_.pc();
}
}
void FrameIter::settleOnActivation() {
MOZ_ASSERT(!data_.cx_->inUnsafeCallWithABI);
while (true) {
if (data_.activations_.done()) {
data_.state_ = DONE;
return;
}
Activation* activation = data_.activations_.activation();
if (activation->isJit()) {
data_.jitFrames_ = JitFrameIter(activation->asJit());
data_.jitFrames_.skipNonScriptedJSFrames();
if (data_.jitFrames_.done()) {
// It's possible to have an JitActivation with no scripted
// frames, for instance if we hit an over-recursion during
// bailout.
++data_.activations_;
continue;
}
data_.state_ = JIT;
nextJitFrame();
return;
}
MOZ_ASSERT(activation->isInterpreter());
InterpreterActivation* interpAct = activation->asInterpreter();
data_.interpFrames_ = InterpreterFrameIterator(interpAct);
// If we OSR'ed into JIT code, skip the interpreter frame so that
// the same frame is not reported twice.
if (data_.interpFrames_.frame()->runningInJit()) {
++data_.interpFrames_;
if (data_.interpFrames_.done()) {
++data_.activations_;
continue;
}
}
MOZ_ASSERT(!data_.interpFrames_.frame()->runningInJit());
data_.pc_ = data_.interpFrames_.pc();
data_.state_ = INTERP;
return;
}
}
FrameIter::Data::Data(JSContext* cx, DebuggerEvalOption debuggerEvalOption,
JSPrincipals* principals)
: cx_(cx),
debuggerEvalOption_(debuggerEvalOption),
principals_(principals),
state_(DONE),
pc_(nullptr),
interpFrames_(nullptr),
activations_(cx),
ionInlineFrameNo_(0) {}
FrameIter::Data::Data(const FrameIter::Data& other) = default;
FrameIter::FrameIter(JSContext* cx, DebuggerEvalOption debuggerEvalOption)
: data_(cx, debuggerEvalOption, nullptr),
ionInlineFrames_(cx, (js::jit::JSJitFrameIter*)nullptr) {
settleOnActivation();
// No principals so we can see all frames.
MOZ_ASSERT_IF(!done(), principalsSubsumeFrame());
}
FrameIter::FrameIter(JSContext* cx, DebuggerEvalOption debuggerEvalOption,
JSPrincipals* principals)
: data_(cx, debuggerEvalOption, principals),
ionInlineFrames_(cx, (js::jit::JSJitFrameIter*)nullptr) {
settleOnActivation();
// If we're not allowed to see this frame, call operator++ to skip this (and
// other) cross-origin frames.
if (!done() && !principalsSubsumeFrame()) {
++*this;
}
}
FrameIter::FrameIter(const FrameIter& other)
: data_(other.data_),
ionInlineFrames_(other.data_.cx_,
isIonScripted() ? &other.ionInlineFrames_ : nullptr) {}
FrameIter::FrameIter(const Data& data)
: data_(data),
ionInlineFrames_(data.cx_, isIonScripted() ? &jsJitFrame() : nullptr) {
MOZ_ASSERT(data.cx_);
if (isIonScripted()) {
while (ionInlineFrames_.frameNo() != data.ionInlineFrameNo_) {
++ionInlineFrames_;
}
}
}
void FrameIter::nextJitFrame() {
MOZ_ASSERT(data_.jitFrames_.isSome());
if (isJSJit()) {
if (jsJitFrame().isIonScripted()) {
ionInlineFrames_.resetOn(&jsJitFrame());
data_.pc_ = ionInlineFrames_.pc();
} else {
MOZ_ASSERT(jsJitFrame().isBaselineJS());
jsJitFrame().baselineScriptAndPc(nullptr, &data_.pc_);
}
return;
}
MOZ_ASSERT(isWasm());
data_.pc_ = nullptr;
}
void FrameIter::popJitFrame() {
MOZ_ASSERT(data_.state_ == JIT);
MOZ_ASSERT(data_.jitFrames_.isSome());
if (isJSJit() && jsJitFrame().isIonScripted() && ionInlineFrames_.more()) {
++ionInlineFrames_;
data_.pc_ = ionInlineFrames_.pc();
return;
}
++data_.jitFrames_;
data_.jitFrames_.skipNonScriptedJSFrames();
if (!data_.jitFrames_.done()) {
nextJitFrame();
} else {
data_.jitFrames_.reset();
popActivation();
}
}
FrameIter& FrameIter::operator++() {
while (true) {
switch (data_.state_) {
case DONE:
MOZ_CRASH("Unexpected state");
case INTERP:
if (interpFrame()->isDebuggerEvalFrame() &&
data_.debuggerEvalOption_ == FOLLOW_DEBUGGER_EVAL_PREV_LINK) {
AbstractFramePtr eifPrev = interpFrame()->evalInFramePrev();
popInterpreterFrame();
while (!hasUsableAbstractFramePtr() ||
abstractFramePtr() != eifPrev) {
if (data_.state_ == JIT) {
popJitFrame();
} else {
popInterpreterFrame();
}
}
break;
}
popInterpreterFrame();
break;
case JIT:
popJitFrame();
break;
}
if (done() || principalsSubsumeFrame()) {
break;
}
}
return *this;
}
FrameIter::Data* FrameIter::copyData() const {
Data* data = data_.cx_->new_<Data>(data_);
if (!data) {
return nullptr;
}
if (data && isIonScripted()) {
data->ionInlineFrameNo_ = ionInlineFrames_.frameNo();
}
return data;
}
void* FrameIter::rawFramePtr() const {
switch (data_.state_) {
case DONE:
return nullptr;
case INTERP:
return interpFrame();
case JIT:
if (isJSJit()) {
return jsJitFrame().fp();
}
MOZ_ASSERT(isWasm());
return nullptr;
}
MOZ_CRASH("Unexpected state");
}
JS::Compartment* FrameIter::compartment() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
return data_.activations_->compartment();
}
MOZ_CRASH("Unexpected state");
}
Realm* FrameIter::realm() const {
MOZ_ASSERT(!done());
if (hasScript()) {
return script()->realm();
}
return wasmInstance()->realm();
}
bool FrameIter::isEvalFrame() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
return interpFrame()->isEvalFrame();
case JIT:
if (isJSJit()) {
if (jsJitFrame().isBaselineJS()) {
return jsJitFrame().baselineFrame()->isEvalFrame();
}
MOZ_ASSERT(!script()->isForEval());
return false;
}
MOZ_ASSERT(isWasm());
return false;
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::isModuleFrame() const {
MOZ_ASSERT(!done());
if (hasScript()) {
return script()->isModule();
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::isFunctionFrame() const {
MOZ_ASSERT(!done());
switch (data_.state_) {
case DONE:
break;
case INTERP:
return interpFrame()->isFunctionFrame();
case JIT:
if (isJSJit()) {
if (jsJitFrame().isBaselineJS()) {
return jsJitFrame().baselineFrame()->isFunctionFrame();
}
return script()->isFunction();
}
MOZ_ASSERT(isWasm());
return false;
}
MOZ_CRASH("Unexpected state");
}
JSAtom* FrameIter::maybeFunctionDisplayAtom() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
if (isWasm()) {
return wasmFrame().functionDisplayAtom();
}
if (isFunctionFrame()) {
return calleeTemplate()->fullDisplayAtom();
}
return nullptr;
}
MOZ_CRASH("Unexpected state");
}
ScriptSource* FrameIter::scriptSource() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
return script()->scriptSource();
}
MOZ_CRASH("Unexpected state");
}
const char* FrameIter::filename() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
if (isWasm()) {
return wasmFrame().filename();
}
return script()->filename();
}
MOZ_CRASH("Unexpected state");
}
const char16_t* FrameIter::displayURL() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
if (isWasm()) {
return wasmFrame().displayURL();
}
ScriptSource* ss = script()->scriptSource();
return ss->hasDisplayURL() ? ss->displayURL() : nullptr;
}
MOZ_CRASH("Unexpected state");
}
unsigned FrameIter::computeLine(JS::TaggedColumnNumberOneOrigin* column) const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
if (isWasm()) {
return wasmFrame().computeLine(column);
}
JS::LimitedColumnNumberOneOrigin columnNumber;
unsigned lineNumber = PCToLineNumber(script(), pc(), &columnNumber);
if (column) {
*column = JS::TaggedColumnNumberOneOrigin(columnNumber);
}
return lineNumber;
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::mutedErrors() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
case JIT:
if (isWasm()) {
return wasmFrame().mutedErrors();
}
return script()->mutedErrors();
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::isConstructing() const {
switch (data_.state_) {
case DONE:
break;
case JIT:
MOZ_ASSERT(isJSJit());
if (jsJitFrame().isIonScripted()) {
return ionInlineFrames_.isConstructing();
}
MOZ_ASSERT(jsJitFrame().isBaselineJS());
return jsJitFrame().isConstructing();
case INTERP:
return interpFrame()->isConstructing();
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::ensureHasRematerializedFrame(JSContext* cx) {
MOZ_ASSERT(isIon());
return !!activation()->asJit()->getRematerializedFrame(cx, jsJitFrame());
}
bool FrameIter::hasUsableAbstractFramePtr() const {
switch (data_.state_) {
case DONE:
return false;
case JIT:
if (isJSJit()) {
if (jsJitFrame().isBaselineJS()) {
return true;
}
MOZ_ASSERT(jsJitFrame().isIonScripted());
return !!activation()->asJit()->lookupRematerializedFrame(
jsJitFrame().fp(), ionInlineFrames_.frameNo());
}
MOZ_ASSERT(isWasm());
return wasmFrame().debugEnabled();
case INTERP:
return true;
}
MOZ_CRASH("Unexpected state");
}
AbstractFramePtr FrameIter::abstractFramePtr() const {
MOZ_ASSERT(hasUsableAbstractFramePtr());
switch (data_.state_) {
case DONE:
break;
case JIT: {
if (isJSJit()) {
if (jsJitFrame().isBaselineJS()) {
return jsJitFrame().baselineFrame();
}
MOZ_ASSERT(isIonScripted());
return activation()->asJit()->lookupRematerializedFrame(
jsJitFrame().fp(), ionInlineFrames_.frameNo());
}
MOZ_ASSERT(isWasm());
MOZ_ASSERT(wasmFrame().debugEnabled());
return wasmFrame().debugFrame();
}
case INTERP:
MOZ_ASSERT(interpFrame());
return AbstractFramePtr(interpFrame());
}
MOZ_CRASH("Unexpected state");
}
void FrameIter::updatePcQuadratic() {
switch (data_.state_) {
case DONE:
break;
case INTERP: {
InterpreterFrame* frame = interpFrame();
InterpreterActivation* activation = data_.activations_->asInterpreter();
// Look for the current frame.
data_.interpFrames_ = InterpreterFrameIterator(activation);
while (data_.interpFrames_.frame() != frame) {
++data_.interpFrames_;
}
// Update the pc.
MOZ_ASSERT(data_.interpFrames_.frame() == frame);
data_.pc_ = data_.interpFrames_.pc();
return;
}
case JIT:
if (jsJitFrame().isBaselineJS()) {
jit::BaselineFrame* frame = jsJitFrame().baselineFrame();
jit::JitActivation* activation = data_.activations_->asJit();
// activation's exitFP may be invalid, so create a new
// activation iterator.
data_.activations_ = ActivationIterator(data_.cx_);
while (data_.activations_.activation() != activation) {
++data_.activations_;
}
// Look for the current frame.
data_.jitFrames_ = JitFrameIter(data_.activations_->asJit());
while (!isJSJit() || !jsJitFrame().isBaselineJS() ||
jsJitFrame().baselineFrame() != frame) {
++data_.jitFrames_;
}
// Update the pc.
MOZ_ASSERT(jsJitFrame().baselineFrame() == frame);
jsJitFrame().baselineScriptAndPc(nullptr, &data_.pc_);
return;
}
break;
}
MOZ_CRASH("Unexpected state");
}
void FrameIter::wasmUpdateBytecodeOffset() {
MOZ_RELEASE_ASSERT(isWasm(), "Unexpected state");
wasm::DebugFrame* frame = wasmFrame().debugFrame();
// Relookup the current frame, updating the bytecode offset in the process.
data_.jitFrames_ = JitFrameIter(data_.activations_->asJit());
while (wasmFrame().debugFrame() != frame) {
++data_.jitFrames_;
}
MOZ_ASSERT(wasmFrame().debugFrame() == frame);
}
JSFunction* FrameIter::calleeTemplate() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
MOZ_ASSERT(isFunctionFrame());
return &interpFrame()->callee();
case JIT:
if (jsJitFrame().isBaselineJS()) {
return jsJitFrame().callee();
}
MOZ_ASSERT(jsJitFrame().isIonScripted());
return ionInlineFrames_.calleeTemplate();
}
MOZ_CRASH("Unexpected state");
}
JSFunction* FrameIter::callee(JSContext* cx) const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
return calleeTemplate();
case JIT:
if (isIonScripted()) {
jit::MaybeReadFallback recover(cx, activation()->asJit(),
&jsJitFrame());
return ionInlineFrames_.callee(recover);
}
MOZ_ASSERT(jsJitFrame().isBaselineJS());
return calleeTemplate();
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::matchCallee(JSContext* cx, JS::Handle<JSFunction*> fun) const {
// Use the calleeTemplate to rule out a match without needing to invalidate to
// find the actual callee. The real callee my be a clone of the template which
// should *not* be considered a match.
Rooted<JSFunction*> currentCallee(cx, calleeTemplate());
if (currentCallee->nargs() != fun->nargs()) {
return false;
}
if (currentCallee->flags().stableAcrossClones() !=
fun->flags().stableAcrossClones()) {
return false;
}
// The calleeTemplate for a callee will always have the same BaseScript. If
// the script clones do not use the same script, they also have a different
// group and Ion will not inline them interchangeably.
//
// See: js::jit::InlineFrameIterator::findNextFrame()
if (currentCallee->hasBaseScript()) {
if (currentCallee->baseScript() != fun->baseScript()) {
return false;
}
}
return callee(cx) == fun;
}
unsigned FrameIter::numActualArgs() const {
switch (data_.state_) {
case DONE:
break;
case INTERP:
MOZ_ASSERT(isFunctionFrame());
return interpFrame()->numActualArgs();
case JIT:
if (isIonScripted()) {
return ionInlineFrames_.numActualArgs();
}
MOZ_ASSERT(jsJitFrame().isBaselineJS());
return jsJitFrame().numActualArgs();
}
MOZ_CRASH("Unexpected state");
}
unsigned FrameIter::numFormalArgs() const {
return script()->function()->nargs();
}
Value FrameIter::unaliasedActual(unsigned i,
MaybeCheckAliasing checkAliasing) const {
return abstractFramePtr().unaliasedActual(i, checkAliasing);
}
JSObject* FrameIter::environmentChain(JSContext* cx) const {
switch (data_.state_) {
case DONE:
break;
case JIT:
if (isJSJit()) {
if (isIonScripted()) {
jit::MaybeReadFallback recover(cx, activation()->asJit(),
&jsJitFrame());
return ionInlineFrames_.environmentChain(recover);
}
return jsJitFrame().baselineFrame()->environmentChain();
}
MOZ_ASSERT(isWasm());
return wasmFrame().debugFrame()->environmentChain();
case INTERP:
return interpFrame()->environmentChain();
}
MOZ_CRASH("Unexpected state");
}
bool FrameIter::hasInitialEnvironment(JSContext* cx) const {
if (hasUsableAbstractFramePtr()) {
return abstractFramePtr().hasInitialEnvironment();
}
if (isWasm()) {
// See JSFunction::needsFunctionEnvironmentObjects().
return false;
}
MOZ_ASSERT(isJSJit());
MOZ_ASSERT(isIonScripted());
bool hasInitialEnv = false;
jit::MaybeReadFallback recover(cx, activation()->asJit(), &jsJitFrame());
ionInlineFrames_.environmentChain(recover, &hasInitialEnv);
return hasInitialEnv;
}
CallObject& FrameIter::callObj(JSContext* cx) const {
MOZ_ASSERT(calleeTemplate()->needsCallObject());
MOZ_ASSERT(hasInitialEnvironment(cx));
JSObject* pobj = environmentChain(cx);
while (!pobj->is<CallObject>()) {
pobj = pobj->enclosingEnvironment();
}
return pobj->as<CallObject>();
}
bool FrameIter::hasArgsObj() const { return abstractFramePtr().hasArgsObj(); }
ArgumentsObject& FrameIter::argsObj() const {
MOZ_ASSERT(hasArgsObj());
return abstractFramePtr().argsObj();
}
Value FrameIter::thisArgument(JSContext* cx) const {
MOZ_ASSERT(isFunctionFrame());
switch (data_.state_) {
case DONE:
break;
case JIT:
if (isIonScripted()) {
jit::MaybeReadFallback recover(cx, activation()->asJit(),
&jsJitFrame());
return ionInlineFrames_.thisArgument(recover);
}
return jsJitFrame().baselineFrame()->thisArgument();
case INTERP:
return interpFrame()->thisArgument();
}
MOZ_CRASH("Unexpected state");
}
Value FrameIter::returnValue() const {
switch (data_.state_) {
case DONE:
break;
case JIT:
if (jsJitFrame().isBaselineJS()) {
return jsJitFrame().baselineFrame()->returnValue();
}
break;
case INTERP:
return interpFrame()->returnValue();
}
MOZ_CRASH("Unexpected state");
}
void FrameIter::setReturnValue(const Value& v) {
switch (data_.state_) {
case DONE:
break;
case JIT:
if (jsJitFrame().isBaselineJS()) {
jsJitFrame().baselineFrame()->setReturnValue(v);
return;
}
break;
case INTERP:
interpFrame()->setReturnValue(v);
return;
}
MOZ_CRASH("Unexpected state");
}
size_t FrameIter::numFrameSlots() const {
switch (data_.state_) {
case DONE:
break;
case JIT: {
if (isIonScripted()) {
return ionInlineFrames_.snapshotIterator().numAllocations() -
ionInlineFrames_.script()->nfixed();
}
uint32_t numValueSlots = jsJitFrame().baselineFrameNumValueSlots();
return numValueSlots - jsJitFrame().script()->nfixed();
}
case INTERP:
MOZ_ASSERT(data_.interpFrames_.sp() >= interpFrame()->base());
return data_.interpFrames_.sp() - interpFrame()->base();
}
MOZ_CRASH("Unexpected state");
}
Value FrameIter::frameSlotValue(size_t index) const {
switch (data_.state_) {
case DONE:
break;
case JIT:
if (isIonScripted()) {
jit::SnapshotIterator si(ionInlineFrames_.snapshotIterator());
index += ionInlineFrames_.script()->nfixed();
return si.maybeReadAllocByIndex(index);
}
index += jsJitFrame().script()->nfixed();
return *jsJitFrame().baselineFrame()->valueSlot(index);
case INTERP:
return interpFrame()->base()[index];
}
MOZ_CRASH("Unexpected state");
}
#ifdef DEBUG
bool js::SelfHostedFramesVisible() {
static bool checked = false;
static bool visible = false;
if (!checked) {
checked = true;
char* env = getenv("MOZ_SHOW_ALL_JS_FRAMES");
visible = !!env;
}
return visible;
}
#endif
void NonBuiltinFrameIter::settle() {
if (!SelfHostedFramesVisible()) {
while (!done() && hasScript() && script()->selfHosted()) {
FrameIter::operator++();
}
}
}
void NonBuiltinScriptFrameIter::settle() {
if (!SelfHostedFramesVisible()) {
while (!done() && script()->selfHosted()) {
ScriptFrameIter::operator++();
}
}
}
bool FrameIter::inPrologue() const {
if (pc() < script()->main()) {
return true;
}
// If we do a VM call before pushing locals in baseline, the stack frame will
// not include space for those locals.
if (pc() == script()->code() && isBaseline() &&
jsJitFrame().baselineFrameNumValueSlots() < script()->nfixed()) {
return true;
}
return false;
}