michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "jit/BaselineFrame-inl.h"
michael@0: 
michael@0: #include "jit/BaselineJIT.h"
michael@0: #include "jit/Ion.h"
michael@0: #include "vm/Debugger.h"
michael@0: #include "vm/ScopeObject.h"
michael@0: 
michael@0: #include "jit/IonFrames-inl.h"
michael@0: #include "vm/Stack-inl.h"
michael@0: 
michael@0: using namespace js;
michael@0: using namespace js::jit;
michael@0: 
michael@0: static void
michael@0: MarkLocals(BaselineFrame *frame, JSTracer *trc, unsigned start, unsigned end)
michael@0: {
michael@0:     if (start < end) {
michael@0:         // Stack grows down.
michael@0:         Value *last = frame->valueSlot(end - 1);
michael@0:         gc::MarkValueRootRange(trc, end - start, last, "baseline-stack");
michael@0:     }
michael@0: }
michael@0: 
michael@0: void
michael@0: BaselineFrame::trace(JSTracer *trc, JitFrameIterator &frameIterator)
michael@0: {
michael@0:     replaceCalleeToken(MarkCalleeToken(trc, calleeToken()));
michael@0: 
michael@0:     gc::MarkValueRoot(trc, &thisValue(), "baseline-this");
michael@0: 
michael@0:     // Mark actual and formal args.
michael@0:     if (isNonEvalFunctionFrame()) {
michael@0:         unsigned numArgs = js::Max(numActualArgs(), numFormalArgs());
michael@0:         gc::MarkValueRootRange(trc, numArgs, argv(), "baseline-args");
michael@0:     }
michael@0: 
michael@0:     // Mark scope chain, if it exists.
michael@0:     if (scopeChain_)
michael@0:         gc::MarkObjectRoot(trc, &scopeChain_, "baseline-scopechain");
michael@0: 
michael@0:     // Mark return value.
michael@0:     if (hasReturnValue())
michael@0:         gc::MarkValueRoot(trc, returnValue().address(), "baseline-rval");
michael@0: 
michael@0:     if (isEvalFrame())
michael@0:         gc::MarkScriptRoot(trc, &evalScript_, "baseline-evalscript");
michael@0: 
michael@0:     if (hasArgsObj())
michael@0:         gc::MarkObjectRoot(trc, &argsObj_, "baseline-args-obj");
michael@0: 
michael@0:     // Mark locals and stack values.
michael@0:     JSScript *script = this->script();
michael@0:     size_t nfixed = script->nfixed();
michael@0:     size_t nlivefixed = script->nfixedvars();
michael@0: 
michael@0:     if (nfixed != nlivefixed) {
michael@0:         jsbytecode *pc;
michael@0:         NestedScopeObject *staticScope;
michael@0: 
michael@0:         frameIterator.baselineScriptAndPc(nullptr, &pc);
michael@0:         staticScope = script->getStaticScope(pc);
michael@0:         while (staticScope && !staticScope->is<StaticBlockObject>())
michael@0:             staticScope = staticScope->enclosingNestedScope();
michael@0: 
michael@0:         if (staticScope) {
michael@0:             StaticBlockObject &blockObj = staticScope->as<StaticBlockObject>();
michael@0:             nlivefixed = blockObj.localOffset() + blockObj.numVariables();
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     JS_ASSERT(nlivefixed <= nfixed);
michael@0:     JS_ASSERT(nlivefixed >= script->nfixedvars());
michael@0: 
michael@0:     // NB: It is possible that numValueSlots() could be zero, even if nfixed is
michael@0:     // nonzero.  This is the case if the function has an early stack check.
michael@0:     if (numValueSlots() == 0)
michael@0:         return;
michael@0: 
michael@0:     JS_ASSERT(nfixed <= numValueSlots());
michael@0: 
michael@0:     if (nfixed == nlivefixed) {
michael@0:         // All locals are live.
michael@0:         MarkLocals(this, trc, 0, numValueSlots());
michael@0:     } else {
michael@0:         // Mark operand stack.
michael@0:         MarkLocals(this, trc, nfixed, numValueSlots());
michael@0: 
michael@0:         // Clear dead locals.
michael@0:         while (nfixed > nlivefixed)
michael@0:             unaliasedLocal(--nfixed, DONT_CHECK_ALIASING).setUndefined();
michael@0: 
michael@0:         // Mark live locals.
michael@0:         MarkLocals(this, trc, 0, nlivefixed);
michael@0:     }
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineFrame::copyRawFrameSlots(AutoValueVector *vec) const
michael@0: {
michael@0:     unsigned nfixed = script()->nfixed();
michael@0:     unsigned nformals = numFormalArgs();
michael@0: 
michael@0:     if (!vec->resize(nformals + nfixed))
michael@0:         return false;
michael@0: 
michael@0:     mozilla::PodCopy(vec->begin(), argv(), nformals);
michael@0:     for (unsigned i = 0; i < nfixed; i++)
michael@0:         (*vec)[nformals + i] = *valueSlot(i);
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineFrame::strictEvalPrologue(JSContext *cx)
michael@0: {
michael@0:     JS_ASSERT(isStrictEvalFrame());
michael@0: 
michael@0:     CallObject *callobj = CallObject::createForStrictEval(cx, this);
michael@0:     if (!callobj)
michael@0:         return false;
michael@0: 
michael@0:     pushOnScopeChain(*callobj);
michael@0:     flags_ |= HAS_CALL_OBJ;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineFrame::heavyweightFunPrologue(JSContext *cx)
michael@0: {
michael@0:     return initFunctionScopeObjects(cx);
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineFrame::initFunctionScopeObjects(JSContext *cx)
michael@0: {
michael@0:     JS_ASSERT(isNonEvalFunctionFrame());
michael@0:     JS_ASSERT(fun()->isHeavyweight());
michael@0: 
michael@0:     CallObject *callobj = CallObject::createForFunction(cx, this);
michael@0:     if (!callobj)
michael@0:         return false;
michael@0: 
michael@0:     pushOnScopeChain(*callobj);
michael@0:     flags_ |= HAS_CALL_OBJ;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: BaselineFrame::initForOsr(InterpreterFrame *fp, uint32_t numStackValues)
michael@0: {
michael@0:     mozilla::PodZero(this);
michael@0: 
michael@0:     scopeChain_ = fp->scopeChain();
michael@0: 
michael@0:     if (fp->hasCallObjUnchecked())
michael@0:         flags_ |= BaselineFrame::HAS_CALL_OBJ;
michael@0: 
michael@0:     if (fp->isEvalFrame()) {
michael@0:         flags_ |= BaselineFrame::EVAL;
michael@0:         evalScript_ = fp->script();
michael@0:     }
michael@0: 
michael@0:     if (fp->script()->needsArgsObj() && fp->hasArgsObj()) {
michael@0:         flags_ |= BaselineFrame::HAS_ARGS_OBJ;
michael@0:         argsObj_ = &fp->argsObj();
michael@0:     }
michael@0: 
michael@0:     if (fp->hasHookData()) {
michael@0:         flags_ |= BaselineFrame::HAS_HOOK_DATA;
michael@0:         hookData_ = fp->hookData();
michael@0:     }
michael@0: 
michael@0:     if (fp->hasReturnValue())
michael@0:         setReturnValue(fp->returnValue());
michael@0: 
michael@0:     // If the interpreter pushed an SPS frame when it entered the function, the
michael@0:     // interpreter will pop it after the OSR trampoline returns.  In order for
michael@0:     // the Baseline frame to have its SPS flag set, it must have its own SPS
michael@0:     // frame, which the Baseline code will pop on return.  Note that the
michael@0:     // profiler may have been enabled or disabled after the function was entered
michael@0:     // but before OSR.
michael@0:     JSContext *cx = GetJSContextFromJitCode();
michael@0:     SPSProfiler *p = &(cx->runtime()->spsProfiler);
michael@0:     if (p->enabled()) {
michael@0:         p->enter(fp->script(), fp->maybeFun());
michael@0:         flags_ |= BaselineFrame::HAS_PUSHED_SPS_FRAME;
michael@0:     }
michael@0: 
michael@0:     frameSize_ = BaselineFrame::FramePointerOffset +
michael@0:         BaselineFrame::Size() +
michael@0:         numStackValues * sizeof(Value);
michael@0: 
michael@0:     JS_ASSERT(numValueSlots() == numStackValues);
michael@0: 
michael@0:     for (uint32_t i = 0; i < numStackValues; i++)
michael@0:         *valueSlot(i) = fp->slots()[i];
michael@0: 
michael@0:     if (cx->compartment()->debugMode()) {
michael@0:         // In debug mode, update any Debugger.Frame objects for the
michael@0:         // InterpreterFrame to point to the BaselineFrame.
michael@0: 
michael@0:         // The caller pushed a fake return address. ScriptFrameIter, used by the
michael@0:         // debugger, wants a valid return address, but it's okay to just pick one.
michael@0:         // In debug mode there's always at least 1 ICEntry (since there are always
michael@0:         // debug prologue/epilogue calls).
michael@0:         JitFrameIterator iter(cx);
michael@0:         JS_ASSERT(iter.returnAddress() == nullptr);
michael@0:         BaselineScript *baseline = fp->script()->baselineScript();
michael@0:         iter.current()->setReturnAddress(baseline->returnAddressForIC(baseline->icEntry(0)));
michael@0: 
michael@0:         if (!Debugger::handleBaselineOsr(cx, fp, this))
michael@0:             return false;
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0: }