Devtools: expose scopes source location to debugger

src/debug/debug-scopes.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/debug/debug-scopes.h"
 
 #include "src/ast/scopes.h"
 #include "src/debug/debug.h"
 #include "src/frames-inl.h"
 #include "src/globals.h"
@@ skipping 55 matching lines @@
 
   if (ignore_nested_scopes) {
     if (scope_info->HasContext()) {
       context_ = Handle<Context>(context_->declaration_context(), isolate_);
     } else {
       while (context_->closure() == *function) {
         context_ = Handle<Context>(context_->previous(), isolate_);
       }
     }
     if (scope_info->scope_type() == FUNCTION_SCOPE) {
-      nested_scope_chain_.Add(scope_info);
+      nested_scope_chain_.Add(ExtendedScopeInfo(scope_info, 0, 0));

[Yang, 2016/02/25 21:25:17]

the function has a start and an end position, why do we use 0 here?

[sergeyv, 2016/02/26 00:29:29]

Done.

     }
     if (!collect_non_locals) return;
   }
 
   // Reparse the code and analyze the scopes.
   Scope* scope = NULL;
   // Check whether we are in global, eval or function code.
   Zone zone;
   if (scope_info->scope_type() != FUNCTION_SCOPE) {
     // Global or eval code.
@@ skipping 36 matching lines @@
 
 MUST_USE_RESULT MaybeHandle<JSObject> ScopeIterator::MaterializeScopeDetails() {
   // Calculate the size of the result.
   Handle<FixedArray> details =
       isolate_->factory()->NewFixedArray(kScopeDetailsSize);
   // Fill in scope details.
   details->set(kScopeDetailsTypeIndex, Smi::FromInt(Type()));
   Handle<JSObject> scope_object;
   ASSIGN_RETURN_ON_EXCEPTION(isolate_, scope_object, ScopeObject(), JSObject);
   details->set(kScopeDetailsObjectIndex, *scope_object);
-  if (HasContext() && CurrentContext()->closure() != NULL) {
-    Handle<String> closure_name = JSFunction::GetDebugName(
-        Handle<JSFunction>(CurrentContext()->closure()));
+  Handle<JSFunction> jsFunction = HasContext()

[Yang, 2016/02/25 21:25:17]

naming convention would be js_function

[sergeyv, 2016/02/26 00:29:29]

Done.

+                                      ? handle(CurrentContext()->closure())
+                                      : Handle<JSFunction>::null();
+  if (!jsFunction.is_null()) {
+    Handle<String> closure_name = JSFunction::GetDebugName(jsFunction);
     if (!closure_name.is_null() && (closure_name->length() != 0))
       details->set(kScopeDetailsNameIndex, *closure_name);
   }
+  if (Type() == ScopeTypeGlobal || Type() == ScopeTypeScript)

[Yang, 2016/02/25 21:25:17]

curly brackets on line wrapped if-statement please.

[sergeyv, 2016/02/26 00:29:29]

Done.

+    return isolate_->factory()->NewJSArrayWithElements(details);
+
+  int start_position = 0;
+  int end_position = 0;
+  if (!nested_scope_chain_.is_empty()) {
+    jsFunction = GetFunction();
+    start_position = nested_scope_chain_.last().start_position;
+    end_position = nested_scope_chain_.last().end_position;
+  } else if (!jsFunction.is_null()) {
+    start_position = jsFunction->shared()->start_position();
+    end_position = jsFunction->shared()->end_position();
+  }
+
+  if (!jsFunction.is_null()) {
+    details->set(kScopeDetailsStartPositionIndex, Smi::FromInt(start_position));
+    details->set(kScopeDetailsEndPositionIndex, Smi::FromInt(end_position));
+    details->set(kScopeDetailsFunctionIndex, *jsFunction);
+  }
   return isolate_->factory()->NewJSArrayWithElements(details);
 }
 
 
 void ScopeIterator::Next() {
   DCHECK(!failed_);
   ScopeType scope_type = Type();
   if (scope_type == ScopeTypeGlobal) {
     // The global scope is always the last in the chain.
     DCHECK(context_->IsNativeContext());
     context_ = Handle<Context>();
     return;
   }
   if (scope_type == ScopeTypeScript) {
     seen_script_scope_ = true;
     if (context_->IsScriptContext()) {
       context_ = Handle<Context>(context_->previous(), isolate_);
     }
     if (!nested_scope_chain_.is_empty()) {
-      DCHECK_EQ(nested_scope_chain_.last()->scope_type(), SCRIPT_SCOPE);
+      DCHECK_EQ(nested_scope_chain_.last().scope_info->scope_type(),
+                SCRIPT_SCOPE);
       nested_scope_chain_.RemoveLast();
       DCHECK(nested_scope_chain_.is_empty());
     }
     CHECK(context_->IsNativeContext());
     return;
   }
   if (nested_scope_chain_.is_empty()) {
     context_ = Handle<Context>(context_->previous(), isolate_);
   } else {
-    if (nested_scope_chain_.last()->HasContext()) {
+    if (nested_scope_chain_.last().scope_info->HasContext()) {
       DCHECK(context_->previous() != NULL);
       context_ = Handle<Context>(context_->previous(), isolate_);
     }
     nested_scope_chain_.RemoveLast();
   }
 }
 
 
 // Return the type of the current scope.
 ScopeIterator::ScopeType ScopeIterator::Type() {
   DCHECK(!failed_);
   if (!nested_scope_chain_.is_empty()) {
-    Handle<ScopeInfo> scope_info = nested_scope_chain_.last();
+    Handle<ScopeInfo> scope_info = nested_scope_chain_.last().scope_info;
     switch (scope_info->scope_type()) {
       case FUNCTION_SCOPE:
         DCHECK(context_->IsFunctionContext() || !scope_info->HasContext());
         return ScopeTypeLocal;
       case MODULE_SCOPE:
         DCHECK(context_->IsModuleContext());
         return ScopeTypeModule;
       case SCRIPT_SCOPE:
         DCHECK(context_->IsScriptContext() || context_->IsNativeContext());
         return ScopeTypeScript;
@@ skipping 63 matching lines @@
   }
   UNREACHABLE();
   return Handle<JSObject>();
 }
 
 
 bool ScopeIterator::HasContext() {
   ScopeType type = Type();
   if (type == ScopeTypeBlock || type == ScopeTypeLocal) {
     if (!nested_scope_chain_.is_empty()) {
-      return nested_scope_chain_.last()->HasContext();
+      return nested_scope_chain_.last().scope_info->HasContext();
     }
   }
   return true;
 }
 
 
 bool ScopeIterator::SetVariableValue(Handle<String> variable_name,
                                      Handle<Object> new_value) {
   DCHECK(!failed_);
   switch (Type()) {
@@ skipping 15 matching lines @@
       // TODO(2399): should we implement it?
       break;
   }
   return false;
 }
 
 
 Handle<ScopeInfo> ScopeIterator::CurrentScopeInfo() {
   DCHECK(!failed_);
   if (!nested_scope_chain_.is_empty()) {
-    return nested_scope_chain_.last();
+    return nested_scope_chain_.last().scope_info;
   } else if (context_->IsBlockContext()) {
     return Handle<ScopeInfo>(context_->scope_info());
   } else if (context_->IsFunctionContext()) {
     return Handle<ScopeInfo>(context_->closure()->shared()->scope_info());
   }
   return Handle<ScopeInfo>::null();
 }
 
 
 Handle<Context> ScopeIterator::CurrentContext() {
   DCHECK(!failed_);
   if (Type() == ScopeTypeGlobal || Type() == ScopeTypeScript ||
       nested_scope_chain_.is_empty()) {
     return context_;
-  } else if (nested_scope_chain_.last()->HasContext()) {
+  } else if (nested_scope_chain_.last().scope_info->HasContext()) {
     return context_;
   } else {
     return Handle<Context>();
   }
 }
 
 
 void ScopeIterator::GetNonLocals(List<Handle<String> >* list_out) {
   Handle<String> this_string = isolate_->factory()->this_string();
   for (HashMap::Entry* entry = non_locals_->Start(); entry != nullptr;
@@ skipping 75 matching lines @@
       UNREACHABLE();
   }
   PrintF("\n");
 }
 #endif
 
 
 void ScopeIterator::RetrieveScopeChain(Scope* scope) {
   if (scope != NULL) {
     int source_position = frame_inspector_->GetSourcePosition();
-    scope->GetNestedScopeChain(isolate_, &nested_scope_chain_, source_position);
+    GetNestedScopeChain(isolate_, scope, source_position);
   } else {
     // A failed reparse indicates that the preparser has diverged from the
     // parser or that the preparse data given to the initial parse has been
     // faulty. We fail in debug mode but in release mode we only provide the
     // information we get from the context chain but nothing about
     // completely stack allocated scopes or stack allocated locals.
     // Or it could be due to stack overflow.
     DCHECK(isolate_->has_pending_exception());
     failed_ = true;
   }
@@ skipping 111 matching lines @@
 
 
 // Create a plain JSObject which materializes the block scope for the specified
 // block context.
 Handle<JSObject> ScopeIterator::MaterializeBlockScope() {
   Handle<JSObject> block_scope =
       isolate_->factory()->NewJSObject(isolate_->object_function());
 
   Handle<Context> context = Handle<Context>::null();
   if (!nested_scope_chain_.is_empty()) {
-    Handle<ScopeInfo> scope_info = nested_scope_chain_.last();
+    Handle<ScopeInfo> scope_info = nested_scope_chain_.last().scope_info;
     frame_inspector_->MaterializeStackLocals(block_scope, scope_info);
     if (scope_info->HasContext()) context = CurrentContext();
   } else {
     context = CurrentContext();
   }
 
   if (!context.is_null()) {
     // Fill all context locals.
     CopyContextLocalsToScopeObject(handle(context->scope_info()),
                                    context, block_scope);
@@ skipping 253 matching lines @@
     Handle<Object> value;
     ASSIGN_RETURN_ON_EXCEPTION_VALUE(
         isolate_, value, Object::GetPropertyOrElement(extension, key), false);
     RETURN_ON_EXCEPTION_VALUE(
         isolate_, JSObject::SetOwnPropertyIgnoreAttributes(
             scope_object, key, value, NONE), false);
   }
   return true;
 }
 
+void ScopeIterator::GetNestedScopeChain(Isolate* isolate, Scope* scope,
+                                        int position) {
+  if (!scope->is_eval_scope())

[Yang, 2016/02/25 21:25:17]

curly brackets

[sergeyv, 2016/02/26 00:29:29]

Done.

+    nested_scope_chain_.Add(ExtendedScopeInfo(scope->GetScopeInfo(isolate),
+                                              scope->start_position(),
+                                              scope->end_position()));
+
+  for (int i = 0; i < scope->inner_scopes()->length(); i++) {
+    Scope* inner_scope = scope->inner_scopes()->at(i);
+    int beg_pos = inner_scope->start_position();
+    int end_pos = inner_scope->end_position();
+    DCHECK(beg_pos >= 0 && end_pos >= 0);
+    if (beg_pos <= position && position < end_pos) {
+      GetNestedScopeChain(isolate, inner_scope, position);
+      return;
+    }
+  }
+}
+
 }  // namespace internal
 }  // namespace v8