[wasm] Enable wasm frame inspection for debugging

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index c69b04b0c8327f5dd95a90a8b8ddb945b2ecbe07..7287ceb1865ab214ad49bfbfd08d2a87f13b8733 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -22,12 +22,34 @@
 #include "src/log.h"
 #include "src/messages.h"
 #include "src/snapshot/natives.h"
+#include "src/wasm/wasm-debug.h"
+#include "src/wasm/wasm-module.h"
 
 #include "include/v8-debug.h"
 
 namespace v8 {
 namespace internal {
 
+namespace {
+
+int GetCodeOffset(StandardFrame* frame) {
+  if (frame->is_java_script()) {
+    return FrameSummary::GetFirst(JavaScriptFrame::cast(frame)).code_offset();

[Yang, 2016/06/16 14:10:41]

Is it not feasible to extend FrameSummary for wasm frames?

[Clemens Hammacher, 2016/06/16 17:02:31]

FrameSummary is very JS-specific, and it's only purpose is to encapsulate the
information for a frame with inlined functions.
It seemed inappropriate to try to put wasm information in there (I also
discussed this with Ben several weeks ago).

+  }
+  DCHECK(frame->is_wasm());
+  return static_cast<int>(frame->pc() -
+                          frame->unchecked_code()->instruction_start());
+}
+
+inline int CallOffsetFromCodeOffset(int code_offset, bool is_interpreted) {
+  // Code offset points to the instruction after the call. Subtract 1 to
+  // exclude that instruction from the search. For bytecode, the code offset
+  // still points to the call.
+  return is_interpreted ? code_offset : code_offset - 1;
+}
+
+}  // namespace
+
 Debug::Debug(Isolate* isolate)
     : debug_context_(Handle<Context>()),
       event_listener_(Handle<Object>()),
@@ -260,18 +282,11 @@ BreakLocation BreakLocation::FromCodeOffset(Handle<DebugInfo> debug_info,
   return it->GetBreakLocation();
 }
 
-int CallOffsetFromCodeOffset(int code_offset, bool is_interpreted) {
-  // Code offset points to the instruction after the call. Subtract 1 to
-  // exclude that instruction from the search. For bytecode, the code offset
-  // still points to the call.
-  return is_interpreted ? code_offset : code_offset - 1;
-}
-
 BreakLocation BreakLocation::FromFrame(Handle<DebugInfo> debug_info,
-                                       JavaScriptFrame* frame) {
-  FrameSummary summary = FrameSummary::GetFirst(frame);
+                                       StandardFrame* frame) {
+  int code_offset = GetCodeOffset(frame);
   int call_offset =
-      CallOffsetFromCodeOffset(summary.code_offset(), frame->is_interpreted());
+      CallOffsetFromCodeOffset(code_offset, frame->is_interpreted());
   return FromCodeOffset(debug_info, call_offset);
 }
 
@@ -793,6 +808,9 @@ bool Debug::SetBreakPointForScript(Handle<Script> script,
                                    Handle<Object> break_point_object,
                                    int* source_position,
                                    BreakPositionAlignment alignment) {
+  if (script->type() == Script::TYPE_WASM) {
+    // TODO(clemensh): set breakpoint for wasm.
+  }
   HandleScope scope(isolate_);
 
   // Obtain shared function info for the function.
@@ -1601,23 +1619,26 @@ void Debug::SetAfterBreakTarget(JavaScriptFrame* frame) {
   }
 }
 
-
-bool Debug::IsBreakAtReturn(JavaScriptFrame* frame) {
+bool Debug::IsBreakAtReturn(StandardFrame* frame) {
   HandleScope scope(isolate_);
 
+  if (frame->is_wasm()) {
+    // TODO(clemensh): find out what we want to do for wasm
+    return false;
+  }
+
+  JavaScriptFrame* js_frame = JavaScriptFrame::cast(frame);
   // Get the executing function in which the debug break occurred.
-  Handle<JSFunction> function(JSFunction::cast(frame->function()));
-  Handle<SharedFunctionInfo> shared(function->shared());
+  Handle<SharedFunctionInfo> shared(js_frame->function()->shared());
 
   // With no debug info there are no break points, so we can't be at a return.
   if (!shared->HasDebugInfo()) return false;
 
   DCHECK(!frame->is_optimized());
-  FrameSummary summary = FrameSummary::GetFirst(frame);
-
+  int code_offset = GetCodeOffset(frame);

[Yang, 2016/06/16 14:10:41]

At this point the frame is already known to be a javascript frame, right?

[Clemens Hammacher, 2016/06/16 17:02:31]

Right, but calling the function we already have seemed clearer to me than to
duplicate code here.
I could extract a GetJavaScriptCodeOffset function, and use it here and from
GetCodeOffset. Would you prefer that?

   Handle<DebugInfo> debug_info(shared->GetDebugInfo());
   BreakLocation location =
-      BreakLocation::FromCodeOffset(debug_info, summary.code_offset());
+      BreakLocation::FromCodeOffset(debug_info, code_offset);
   return location.IsReturn() || location.IsTailCall();
 }
 
@@ -2305,10 +2326,10 @@ DebugScope::DebugScope(Debug* debug)
 
   // Create the new break info. If there is no JavaScript frames there is no
   // break frame id.
-  JavaScriptFrameIterator it(isolate());
-  bool has_js_frames = !it.done();
-  debug_->thread_local_.break_frame_id_ = has_js_frames ? it.frame()->id()
-                                                        : StackFrame::NO_ID;
+  StackTraceFrameIterator it(isolate());
+  bool has_frames = !it.done();
+  debug_->thread_local_.break_frame_id_ =
+      has_frames ? it.frame()->id() : StackFrame::NO_ID;
   debug_->SetNextBreakId();
 
   debug_->UpdateState();