Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1063 insertions, 0 deletions

diff --git a/js/src/vm/FrameIter.cpp b/js/src/vm/FrameIter.cpp
new file mode 100644
index 0000000000..b84622ed7f
--- /dev/null
+++ b/js/src/vm/FrameIter.cpp
@@ -0,0 +1,1063 @@
+/* -*- 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::EnsureBareExitFrame
+#include "jit/JSJitFrameIter.h"  // js::jit::{FrameType,InlineFrameIterator,JSJitFrameIter,MaybeReadFallback,SnapshotIterator}
+#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();
+  }
+
+  return asJSJit().script()->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.unwoundIonCallerFP()) {
+      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.unwoundIonCallerFP();
+    jit::FrameType prevFrameType = wasmFrame.unwoundIonFrameType();
+
+    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.
+      EnsureBareExitFrame(act_, prevFrame);
+    }
+  } else if (isWasm()) {
+    ++asWasm();
+  } else {
+    MOZ_CRASH("unhandled case");
+  }
+  settle();
+}
+
+OnlyJSJitFrameIter::OnlyJSJitFrameIter(jit::JitActivation* act)
+    : JitFrameIter(act) {
+  settle();
+}
+
+OnlyJSJitFrameIter::OnlyJSJitFrameIter(JSContext* cx)
+    : OnlyJSJitFrameIter(cx->activation()->asJit()) {}
+
+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()->displayAtom();
+      }
+      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(uint32_t* column) const {
+  switch (data_.state_) {
+    case DONE:
+      break;
+    case INTERP:
+    case JIT:
+      if (isWasm()) {
+        return wasmFrame().computeLine(column);
+      }
+      return PCToLineNumber(script(), pc(), column);
+  }
+
+  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(),
+  //      js::CloneFunctionAndScript()
+  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::newTarget() const {
+  switch (data_.state_) {
+    case DONE:
+      break;
+    case INTERP:
+      return interpFrame()->newTarget();
+    case JIT:
+      MOZ_ASSERT(jsJitFrame().isBaselineJS());
+      return jsJitFrame().baselineFrame()->newTarget();
+  }
+  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++();
+    }
+  }
+}