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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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "jit/BaselineFrame-inl.h"
#include <algorithm>
#include "debugger/DebugAPI.h"
#include "vm/EnvironmentObject.h"
#include "vm/JSContext.h"
#include "jit/JSJitFrameIter-inl.h"
#include "vm/Stack-inl.h"
using namespace js;
using namespace js::jit;
static void TraceLocals(BaselineFrame* frame, JSTracer* trc, unsigned start,
unsigned end) {
if (start < end) {
// Stack grows down.
Value* last = frame->valueSlot(end - 1);
TraceRootRange(trc, end - start, last, "baseline-stack");
}
}
void BaselineFrame::trace(JSTracer* trc, const JSJitFrameIter& frameIterator) {
replaceCalleeToken(TraceCalleeToken(trc, calleeToken()));
// Trace |this|, actual and formal args.
if (isFunctionFrame()) {
TraceRoot(trc, &thisArgument(), "baseline-this");
unsigned numArgs = std::max(numActualArgs(), numFormalArgs());
TraceRootRange(trc, numArgs + isConstructing(), argv(), "baseline-args");
}
// Trace environment chain, if it exists.
if (envChain_) {
TraceRoot(trc, &envChain_, "baseline-envchain");
}
// Trace return value.
if (hasReturnValue()) {
TraceRoot(trc, returnValue().address(), "baseline-rval");
}
if (hasArgsObj()) {
TraceRoot(trc, &argsObj_, "baseline-args-obj");
}
if (runningInInterpreter()) {
TraceRoot(trc, &interpreterScript_, "baseline-interpreterScript");
}
// Trace locals and stack values.
JSScript* script = this->script();
size_t nfixed = script->nfixed();
jsbytecode* pc;
frameIterator.baselineScriptAndPc(nullptr, &pc);
size_t nlivefixed = script->calculateLiveFixed(pc);
uint32_t numValueSlots = frameIterator.baselineFrameNumValueSlots();
// NB: It is possible that numValueSlots could be zero, even if nfixed is
// nonzero. This is the case when we're initializing the environment chain or
// failed the prologue stack check.
if (numValueSlots > 0) {
MOZ_ASSERT(nfixed <= numValueSlots);
if (nfixed == nlivefixed) {
// All locals are live.
TraceLocals(this, trc, 0, numValueSlots);
} else {
// Trace operand stack.
TraceLocals(this, trc, nfixed, numValueSlots);
// Clear dead block-scoped locals.
while (nfixed > nlivefixed) {
unaliasedLocal(--nfixed).setUndefined();
}
// Trace live locals.
TraceLocals(this, trc, 0, nlivefixed);
}
}
if (auto* debugEnvs = script->realm()->debugEnvs()) {
debugEnvs->traceLiveFrame(trc, this);
}
}
bool BaselineFrame::uninlineIsProfilerSamplingEnabled(JSContext* cx) {
return cx->isProfilerSamplingEnabled();
}
bool BaselineFrame::initFunctionEnvironmentObjects(JSContext* cx) {
return js::InitFunctionEnvironmentObjects(cx, this);
}
bool BaselineFrame::pushVarEnvironment(JSContext* cx, Handle<Scope*> scope) {
return js::PushVarEnvironmentObject(cx, scope, this);
}
void BaselineFrame::setInterpreterFields(JSScript* script, jsbytecode* pc) {
uint32_t pcOffset = script->pcToOffset(pc);
interpreterScript_ = script;
interpreterPC_ = pc;
MOZ_ASSERT(icScript_);
interpreterICEntry_ = icScript_->interpreterICEntryFromPCOffset(pcOffset);
}
void BaselineFrame::setInterpreterFieldsForPrologue(JSScript* script) {
interpreterScript_ = script;
interpreterPC_ = script->code();
if (icScript_->numICEntries() > 0) {
interpreterICEntry_ = &icScript_->icEntry(0);
} else {
// If the script does not have any ICEntries (possible for non-function
// scripts) the interpreterICEntry_ field won't be used. Just set it to
// nullptr.
interpreterICEntry_ = nullptr;
}
}
bool BaselineFrame::initForOsr(InterpreterFrame* fp, uint32_t numStackValues) {
mozilla::PodZero(this);
envChain_ = fp->environmentChain();
if (fp->hasInitialEnvironmentUnchecked()) {
flags_ |= BaselineFrame::HAS_INITIAL_ENV;
}
if (fp->script()->needsArgsObj() && fp->hasArgsObj()) {
flags_ |= BaselineFrame::HAS_ARGS_OBJ;
argsObj_ = &fp->argsObj();
}
if (fp->hasReturnValue()) {
setReturnValue(fp->returnValue());
}
icScript_ = fp->script()->jitScript()->icScript();
JSContext* cx =
fp->script()->runtimeFromMainThread()->mainContextFromOwnThread();
Activation* interpActivation = cx->activation()->prev();
jsbytecode* pc = interpActivation->asInterpreter()->regs().pc;
MOZ_ASSERT(fp->script()->containsPC(pc));
// We are doing OSR into the Baseline Interpreter. We can get the pc from the
// C++ interpreter's activation, we just have to skip the JitActivation.
flags_ |= BaselineFrame::RUNNING_IN_INTERPRETER;
setInterpreterFields(pc);
#ifdef DEBUG
debugFrameSize_ = frameSizeForNumValueSlots(numStackValues);
MOZ_ASSERT(debugNumValueSlots() == numStackValues);
#endif
for (uint32_t i = 0; i < numStackValues; i++) {
*valueSlot(i) = fp->slots()[i];
}
if (fp->isDebuggee()) {
// For debuggee frames, update any Debugger.Frame objects for the
// InterpreterFrame to point to the BaselineFrame.
if (!DebugAPI::handleBaselineOsr(cx, fp, this)) {
return false;
}
setIsDebuggee();
}
return true;
}
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