[frames] Simplify frames.h by inlining or removing single-use utilities.

R=petermarshall@chromium.org

Bug: 
Change-Id: Id7187d9e323951e66655d1c6df4676a8e94787dd
Reviewed-on: https://chromium-review.googlesource.com/649247Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47815}

src/accessors.cc

@@ -851,7 +851,10 @@ Handle<Object> GetFunctionArguments(Isolate* isolate,
     }
 
     // Find the frame that holds the actual arguments passed to the function.
-    it.AdvanceToArgumentsFrame();
+    if (it.frame()->has_adapted_arguments()) {
+      it.AdvanceOneFrame();
+      DCHECK(it.frame()->is_arguments_adaptor());
+    }
     frame = it.frame();
 
     // Get the number of arguments and construct an arguments object

src/frames.cc

@@ -137,25 +137,6 @@ void JavaScriptFrameIterator::Advance() {
   } while (!iterator_.done() && !iterator_.frame()->is_java_script());
 }
 
-void JavaScriptFrameIterator::AdvanceToArgumentsFrame() {
-  if (!frame()->has_adapted_arguments()) return;
-  iterator_.Advance();
-  DCHECK(iterator_.frame()->is_arguments_adaptor());
-}
-
-void JavaScriptFrameIterator::AdvanceWhileDebugContext(Debug* debug) {
-  if (!debug->in_debug_scope()) return;
-
-  while (!done()) {
-    Context* context = Context::cast(frame()->context());
-    if (context->native_context() == *debug->debug_context()) {
-      Advance();
-    } else {
-      break;
-    }
-  }
-}
-
 // -------------------------------------------------------------------------
 
 StackTraceFrameIterator::StackTraceFrameIterator(Isolate* isolate)
@@ -185,12 +166,6 @@ bool StackTraceFrameIterator::IsValidFrame(StackFrame* frame) const {
   return frame->is_wasm();
 }
 
-void StackTraceFrameIterator::AdvanceToArgumentsFrame() {
-  if (!is_javascript() || !javascript_frame()->has_adapted_arguments()) return;
-  iterator_.Advance();
-  DCHECK(iterator_.frame()->is_arguments_adaptor());
-}
-
 // -------------------------------------------------------------------------
 
 namespace {
@@ -2032,24 +2007,8 @@ void InternalFrame::Iterate(RootVisitor* v) const {
   if (code->has_tagged_params()) IterateExpressions(v);
 }
 
-
-// -------------------------------------------------------------------------
-
-
-JavaScriptFrame* StackFrameLocator::FindJavaScriptFrame(int n) {
-  DCHECK(n >= 0);
-  for (int i = 0; i <= n; i++) {
-    while (!iterator_.frame()->is_java_script()) iterator_.Advance();
-    if (i == n) return JavaScriptFrame::cast(iterator_.frame());
-    iterator_.Advance();
-  }
-  UNREACHABLE();
-}
-
-
 // -------------------------------------------------------------------------
 
-
 static Map* GcSafeMapOfCodeSpaceObject(HeapObject* object) {
   MapWord map_word = object->map_word();
   return map_word.IsForwardingAddress() ?

src/frames.h

@@ -1205,14 +1205,7 @@ class JavaScriptFrameIterator BASE_EMBEDDED {
 
   bool done() const { return iterator_.done(); }
   void Advance();
-
-  // Advance to the frame holding the arguments for the current
-  // frame. This only affects the current frame if it has adapted
-  // arguments.
-  void AdvanceToArgumentsFrame();
-
-  // Skips the frames that point to the debug context.
-  void AdvanceWhileDebugContext(Debug* debug);
+  void AdvanceOneFrame() { iterator_.Advance(); }
 
  private:
   StackFrameIterator iterator_;
@@ -1228,6 +1221,7 @@ class StackTraceFrameIterator BASE_EMBEDDED {
   StackTraceFrameIterator(Isolate* isolate, StackFrame::Id id);
   bool done() const { return iterator_.done(); }
   void Advance();
+  void AdvanceOneFrame() { iterator_.Advance(); }
 
   inline StandardFrame* frame() const;
 
@@ -1235,11 +1229,6 @@ class StackTraceFrameIterator BASE_EMBEDDED {
   inline bool is_wasm() const;
   inline JavaScriptFrame* javascript_frame() const;
 
-  // Advance to the frame holding the arguments for the current
-  // frame. This only affects the current frame if it is a javascript frame and
-  // has adapted arguments.
-  void AdvanceToArgumentsFrame();
-
  private:
   StackFrameIterator iterator_;
   bool IsValidFrame(StackFrame* frame) const;
@@ -1274,20 +1263,6 @@ class SafeStackFrameIterator: public StackFrameIteratorBase {
   ExternalCallbackScope* external_callback_scope_;
 };
 
-
-class StackFrameLocator BASE_EMBEDDED {
- public:
-  explicit StackFrameLocator(Isolate* isolate) : iterator_(isolate) {}
-
-  // Find the nth JavaScript frame on the stack. The caller must
-  // guarantee that such a frame exists.
-  JavaScriptFrame* FindJavaScriptFrame(int n);
-
- private:
-  StackFrameIterator iterator_;
-};
-
-
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Isolate* isolate, Zone* zone);

src/isolate.cc

@@ -2030,10 +2030,24 @@ void Isolate::SetAbortOnUncaughtExceptionCallback(
   abort_on_uncaught_exception_callback_ = callback;
 }
 
+namespace {
+void AdvanceWhileDebugContext(JavaScriptFrameIterator& it, Debug* debug) {
+  if (!debug->in_debug_scope()) return;
+
+  while (!it.done()) {
+    Context* context = Context::cast(it.frame()->context());
+    if (context->native_context() == *debug->debug_context()) {
+      it.Advance();
+    } else {
+      break;
+    }
+  }
+}
+}  // namespace
 
 Handle<Context> Isolate::GetCallingNativeContext() {
   JavaScriptFrameIterator it(this);
-  it.AdvanceWhileDebugContext(debug_);
+  AdvanceWhileDebugContext(it, debug_);
   if (it.done()) return Handle<Context>::null();
   JavaScriptFrame* frame = it.frame();
   Context* context = Context::cast(frame->context());
@@ -2042,7 +2056,7 @@ Handle<Context> Isolate::GetCallingNativeContext() {
 
 Handle<Context> Isolate::GetIncumbentContext() {
   JavaScriptFrameIterator it(this);
-  it.AdvanceWhileDebugContext(debug_);
+  AdvanceWhileDebugContext(it, debug_);
 
   // 1st candidate: most-recently-entered author function's context
   // if it's newer than the last Context::BackupIncumbentScope entry.

src/runtime/runtime-debug.cc

@@ -635,7 +635,8 @@ RUNTIME_FUNCTION(Runtime_GetFrameDetails) {
   // information (except for what is collected above) is the same.
   if ((inlined_frame_index == 0) &&
       it.javascript_frame()->has_adapted_arguments()) {
-    it.AdvanceToArgumentsFrame();
+    it.AdvanceOneFrame();
+    DCHECK(it.frame()->is_arguments_adaptor());
     frame_inspector.SetArgumentsFrame(it.frame());
   }
 
@@ -1022,12 +1023,13 @@ RUNTIME_FUNCTION(Runtime_DebugPrintScopes) {
 
 #ifdef DEBUG
   // Print the scopes for the top frame.
-  StackFrameLocator locator(isolate);
-  JavaScriptFrame* frame = locator.FindJavaScriptFrame(0);
+  JavaScriptFrameIterator it(isolate);
+  if (!it.done()) {
+    JavaScriptFrame* frame = it.frame();
     FrameInspector frame_inspector(frame, 0, isolate);
-
-  for (ScopeIterator it(isolate, &frame_inspector); !it.Done(); it.Next()) {
-    it.DebugPrint();
+    for (ScopeIterator si(isolate, &frame_inspector); !si.Done(); si.Next()) {
+      si.DebugPrint();
+    }
   }
 #endif
   return isolate->heap()->undefined_value();

src/runtime/runtime-scopes.cc

@@ -387,7 +387,10 @@ std::unique_ptr<Handle<Object>[]> GetCallerArguments(Isolate* isolate,
 
     return param_data;
   } else {
-    it.AdvanceToArgumentsFrame();
+    if (it.frame()->has_adapted_arguments()) {
+      it.AdvanceOneFrame();
+      DCHECK(it.frame()->is_arguments_adaptor());
+    }
     frame = it.frame();
     int args_count = frame->ComputeParametersCount();