1 files changed, 275 insertions, 0 deletions
diff --git a/js/src/jit/RematerializedFrame.h b/js/src/jit/RematerializedFrame.h
new file mode 100644
index 000000000..80bbca34a
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+++ b/js/src/jit/RematerializedFrame.h
@@ -0,0 +1,275 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+#ifndef jit_RematerializedFrame_h
+#define jit_RematerializedFrame_h
+
+#include <algorithm>
+
+#include "jsfun.h"
+
+#include "jit/JitFrameIterator.h"
+#include "jit/JitFrames.h"
+
+#include "vm/EnvironmentObject.h"
+#include "vm/Stack.h"
+
+namespace js {
+namespace jit {
+
+//
+// An optimized frame that has been rematerialized with values read out of
+// Snapshots.
+//
+class RematerializedFrame
+{
+    // See DebugScopes::updateLiveScopes.
+    bool prevUpToDate_;
+
+    // Propagated to the Baseline frame once this is popped.
+    bool isDebuggee_;
+
+    // Has an initial environment has been pushed on the environment chain for
+    // function frames that need a CallObject or eval frames that need a
+    // VarEnvironmentObject?
+    bool hasInitialEnv_;
+
+    // Is this frame constructing?
+    bool isConstructing_;
+
+    // If true, this frame has been on the stack when
+    // |js::SavedStacks::saveCurrentStack| was called, and so there is a
+    // |js::SavedFrame| object cached for this frame.
+    bool hasCachedSavedFrame_;
+
+    // The fp of the top frame associated with this possibly inlined frame.
+    uint8_t* top_;
+
+    // The bytecode at the time of rematerialization.
+    jsbytecode* pc_;
+
+    size_t frameNo_;
+    unsigned numActualArgs_;
+
+    JSScript* script_;
+    JSObject* envChain_;
+    JSFunction* callee_;
+    ArgumentsObject* argsObj_;
+
+    Value returnValue_;
+    Value thisArgument_;
+    Value newTarget_;
+    Value slots_[1];
+
+    RematerializedFrame(JSContext* cx, uint8_t* top, unsigned numActualArgs,
+                        InlineFrameIterator& iter, MaybeReadFallback& fallback);
+
+  public:
+    static RematerializedFrame* New(JSContext* cx, uint8_t* top, InlineFrameIterator& iter,
+                                    MaybeReadFallback& fallback);
+
+    // Rematerialize all remaining frames pointed to by |iter| into |frames|
+    // in older-to-younger order, e.g., frames[0] is the oldest frame.
+    static MOZ_MUST_USE bool RematerializeInlineFrames(JSContext* cx, uint8_t* top,
+                                                       InlineFrameIterator& iter,
+                                                       MaybeReadFallback& fallback,
+                                                       GCVector<RematerializedFrame*>& frames);
+
+    // Free a vector of RematerializedFrames; takes care to call the
+    // destructor. Also clears the vector.
+    static void FreeInVector(GCVector<RematerializedFrame*>& frames);
+
+    bool prevUpToDate() const {
+        return prevUpToDate_;
+    }
+    void setPrevUpToDate() {
+        prevUpToDate_ = true;
+    }
+    void unsetPrevUpToDate() {
+        prevUpToDate_ = false;
+    }
+
+    bool isDebuggee() const {
+        return isDebuggee_;
+    }
+    void setIsDebuggee() {
+        isDebuggee_ = true;
+    }
+    void unsetIsDebuggee() {
+        MOZ_ASSERT(!script()->isDebuggee());
+        isDebuggee_ = false;
+    }
+
+    uint8_t* top() const {
+        return top_;
+    }
+    JSScript* outerScript() const {
+        JitFrameLayout* jsFrame = (JitFrameLayout*)top_;
+        return ScriptFromCalleeToken(jsFrame->calleeToken());
+    }
+    jsbytecode* pc() const {
+        return pc_;
+    }
+    size_t frameNo() const {
+        return frameNo_;
+    }
+    bool inlined() const {
+        return frameNo_ > 0;
+    }
+
+    JSObject* environmentChain() const {
+        return envChain_;
+    }
+
+    template <typename SpecificEnvironment>
+    void pushOnEnvironmentChain(SpecificEnvironment& env) {
+        MOZ_ASSERT(*environmentChain() == env.enclosingEnvironment());
+        envChain_ = &env;
+        if (IsFrameInitialEnvironment(this, env))
+            hasInitialEnv_ = true;
+    }
+
+    template <typename SpecificEnvironment>
+    void popOffEnvironmentChain() {
+        MOZ_ASSERT(envChain_->is<SpecificEnvironment>());
+        envChain_ = &envChain_->as<SpecificEnvironment>().enclosingEnvironment();
+    }
+
+    MOZ_MUST_USE bool initFunctionEnvironmentObjects(JSContext* cx);
+    MOZ_MUST_USE bool pushVarEnvironment(JSContext* cx, HandleScope scope);
+
+    bool hasInitialEnvironment() const {
+        return hasInitialEnv_;
+    }
+    CallObject& callObj() const;
+
+    bool hasArgsObj() const {
+        return !!argsObj_;
+    }
+    ArgumentsObject& argsObj() const {
+        MOZ_ASSERT(hasArgsObj());
+        MOZ_ASSERT(script()->needsArgsObj());
+        return *argsObj_;
+    }
+
+    bool isFunctionFrame() const {
+        return !!script_->functionNonDelazifying();
+    }
+    bool isGlobalFrame() const {
+        return script_->isGlobalCode();
+    }
+    bool isModuleFrame() const {
+        return script_->module();
+    }
+
+    JSScript* script() const {
+        return script_;
+    }
+    JSFunction* callee() const {
+        MOZ_ASSERT(isFunctionFrame());
+        MOZ_ASSERT(callee_);
+        return callee_;
+    }
+    Value calleev() const {
+        return ObjectValue(*callee());
+    }
+    Value& thisArgument() {
+        return thisArgument_;
+    }
+
+    bool isConstructing() const {
+        return isConstructing_;
+    }
+
+    bool hasCachedSavedFrame() const {
+        return hasCachedSavedFrame_;
+    }
+
+    void setHasCachedSavedFrame() {
+        hasCachedSavedFrame_ = true;
+    }
+
+    unsigned numFormalArgs() const {
+        return isFunctionFrame() ? callee()->nargs() : 0;
+    }
+    unsigned numActualArgs() const {
+        return numActualArgs_;
+    }
+    unsigned numArgSlots() const {
+        return (std::max)(numFormalArgs(), numActualArgs());
+    }
+
+    Value* argv() {
+        return slots_;
+    }
+    Value* locals() {
+        return slots_ + numArgSlots();
+    }
+
+    Value& unaliasedLocal(unsigned i) {
+        MOZ_ASSERT(i < script()->nfixed());
+        return locals()[i];
+    }
+    Value& unaliasedFormal(unsigned i, MaybeCheckAliasing checkAliasing = CHECK_ALIASING) {
+        MOZ_ASSERT(i < numFormalArgs());
+        MOZ_ASSERT_IF(checkAliasing, !script()->argsObjAliasesFormals() &&
+                                     !script()->formalIsAliased(i));
+        return argv()[i];
+    }
+    Value& unaliasedActual(unsigned i, MaybeCheckAliasing checkAliasing = CHECK_ALIASING) {
+        MOZ_ASSERT(i < numActualArgs());
+        MOZ_ASSERT_IF(checkAliasing, !script()->argsObjAliasesFormals());
+        MOZ_ASSERT_IF(checkAliasing && i < numFormalArgs(), !script()->formalIsAliased(i));
+        return argv()[i];
+    }
+
+    Value newTarget() {
+        MOZ_ASSERT(isFunctionFrame());
+        if (callee()->isArrow())
+            return callee()->getExtendedSlot(FunctionExtended::ARROW_NEWTARGET_SLOT);
+        MOZ_ASSERT_IF(!isConstructing(), newTarget_.isUndefined());
+        return newTarget_;
+    }
+
+    void setReturnValue(const Value& value) {
+        returnValue_ = value;
+    }
+
+    Value& returnValue() {
+        return returnValue_;
+    }
+
+    void trace(JSTracer* trc);
+    void dump();
+};
+
+} // namespace jit
+} // namespace js
+
+namespace JS {
+
+template <>
+struct MapTypeToRootKind<js::jit::RematerializedFrame*>
+{
+    static const RootKind kind = RootKind::Traceable;
+};
+
+template <>
+struct GCPolicy<js::jit::RematerializedFrame*>
+{
+    static js::jit::RematerializedFrame* initial() {
+        return nullptr;
+    }
+
+    static void trace(JSTracer* trc, js::jit::RematerializedFrame** frame, const char* name) {
+        if (*frame)
+            (*frame)->trace(trc);
+    }
+};
+
+} // namespace JS
+
+#endif // jit_RematerializedFrame_h