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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/. */
#include "jit/BaselineFrame-inl.h"
#include "jit/BaselineJIT.h"
#include "jit/Ion.h"
#include "vm/Debugger.h"
#include "vm/EnvironmentObject.h"
#include "jit/JitFrames-inl.h"
#include "vm/Stack-inl.h"
using namespace js;
using namespace js::jit;
static void
MarkLocals(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, JitFrameIterator& frameIterator)
{
replaceCalleeToken(MarkCalleeToken(trc, calleeToken()));
// Mark |this|, actual and formal args.
if (isFunctionFrame()) {
TraceRoot(trc, &thisArgument(), "baseline-this");
unsigned numArgs = js::Max(numActualArgs(), numFormalArgs());
TraceRootRange(trc, numArgs + isConstructing(), argv(), "baseline-args");
}
// Mark environment chain, if it exists.
if (envChain_)
TraceRoot(trc, &envChain_, "baseline-envchain");
// Mark return value.
if (hasReturnValue())
TraceRoot(trc, returnValue().address(), "baseline-rval");
if (isEvalFrame() && script()->isDirectEvalInFunction())
TraceRoot(trc, evalNewTargetAddress(), "baseline-evalNewTarget");
if (hasArgsObj())
TraceRoot(trc, &argsObj_, "baseline-args-obj");
// Mark 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);
// NB: It is possible that numValueSlots() could be zero, even if nfixed is
// nonzero. This is the case if the function has an early stack check.
if (numValueSlots() == 0)
return;
MOZ_ASSERT(nfixed <= numValueSlots());
if (nfixed == nlivefixed) {
// All locals are live.
MarkLocals(this, trc, 0, numValueSlots());
} else {
// Mark operand stack.
MarkLocals(this, trc, nfixed, numValueSlots());
// Clear dead block-scoped locals.
while (nfixed > nlivefixed)
unaliasedLocal(--nfixed).setUndefined();
// Mark live locals.
MarkLocals(this, trc, 0, nlivefixed);
}
if (script->compartment()->debugEnvs)
script->compartment()->debugEnvs->markLiveFrame(trc, this);
}
bool
BaselineFrame::isNonGlobalEvalFrame() const
{
return isEvalFrame() && script()->enclosingScope()->as<EvalScope>().isNonGlobal();
}
bool
BaselineFrame::initFunctionEnvironmentObjects(JSContext* cx)
{
return js::InitFunctionEnvironmentObjects(cx, this);
}
bool
BaselineFrame::pushVarEnvironment(JSContext* cx, HandleScope scope)
{
return js::PushVarEnvironmentObject(cx, scope, this);
}
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());
frameSize_ = BaselineFrame::FramePointerOffset +
BaselineFrame::Size() +
numStackValues * sizeof(Value);
MOZ_ASSERT(numValueSlots() == numStackValues);
for (uint32_t i = 0; i < numStackValues; i++)
*valueSlot(i) = fp->slots()[i];
if (fp->isDebuggee()) {
JSContext* cx = GetJSContextFromMainThread();
// For debuggee frames, update any Debugger.Frame objects for the
// InterpreterFrame to point to the BaselineFrame.
// The caller pushed a fake return address. ScriptFrameIter, used by the
// debugger, wants a valid return address, but it's okay to just pick one.
// In debug mode there's always at least 1 ICEntry (since there are always
// debug prologue/epilogue calls).
JitFrameIterator iter(cx);
MOZ_ASSERT(iter.returnAddress() == nullptr);
BaselineScript* baseline = fp->script()->baselineScript();
iter.current()->setReturnAddress(baseline->returnAddressForIC(baseline->icEntry(0)));
if (!Debugger::handleBaselineOsr(cx, fp, this))
return false;
setIsDebuggee();
}
return true;
}
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