[v8windbg] Add jsstack command

Change-Id: I8ea9403fa2ae8d45300c291a6d9a55b9293e7c1d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2805731
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#73846}

tools/v8windbg/BUILD.gn

@@ -40,6 +40,8 @@ v8_shared_library("v8windbg") {
     "base/dbgext.def",
     "src/cur-isolate.cc",
     "src/cur-isolate.h",
+    "src/js-stack.cc",
+    "src/js-stack.h",
     "src/list-chunks.cc",
     "src/list-chunks.h",
     "src/local-variables.cc",

tools/v8windbg/README.md

@@ -43,6 +43,8 @@ functions that can be called from within `dx` commands:
   current thread has a JavaScript Isolate associated.
 - `@$listchunks()` returns a list of the memory chunks in the Heap for the
   current Isolate.
+- `@$jsstack()` returns a list of the JS stack frames, including information 
+about script and function.
 
 *Tip:*: to see what objects are present in a chunk of heap memory, you can cast
 it to an array of `TaggedValue`, like this:
@@ -67,6 +69,8 @@ functions declared in `dbgext.h` to create and destroy the extension instance.
 - `cur-isolate.{cc,h}` implements the `IModelMethod` for `@$curisolate()`.
 - `list-chunks.{cc,h}` implements the `IModelMethod` for `@$listchunks()`. Its
   result is a custom object that supports iteration and indexing.
+- `js-stack.{cc,h}` implements the `IModelMethod` for `@$jsstack()`. Its
+  result is a custom object that supports iteration and indexing. 
 - `local-variables.{cc,h}` implements the `IModelPropertyAccessor` that provides
   content to show in the Locals pane for stack frames corresponding to builtins
   or runtime-generated code.

tools/v8windbg/src/js-stack.cc

@@ -0,0 +1,229 @@
+// Copyright 2021 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 "tools/v8windbg/src/js-stack.h"
+
+HRESULT GetJSStackFrames(WRL::ComPtr<IModelObject>& sp_result) {
+  sp_result = nullptr;
+
+  // Get the current context
+  WRL::ComPtr<IDebugHostContext> sp_host_context;
+  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&sp_host_context));
+
+  WRL::ComPtr<IModelObject> sp_curr_thread;
+  RETURN_IF_FAIL(GetCurrentThread(sp_host_context, &sp_curr_thread));
+
+  WRL::ComPtr<IModelObject> sp_stack;
+  RETURN_IF_FAIL(sp_curr_thread->GetKeyValue(L"Stack", &sp_stack, nullptr));
+
+  RETURN_IF_FAIL(sp_stack->GetKeyValue(L"Frames", &sp_result, nullptr));
+
+  return S_OK;
+}
+
+// v8windbg!JSStackAlias::Call
+IFACEMETHODIMP JSStackAlias::Call(IModelObject* p_context_object,
+                                  ULONG64 arg_count,
+                                  _In_reads_(arg_count)
+                                      IModelObject** pp_arguments,
+                                  IModelObject** pp_result,
+                                  IKeyStore** pp_metadata) noexcept {
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&sp_ctx));
+
+  WRL::ComPtr<IModelObject> result;
+  RETURN_IF_FAIL(
+      sp_data_model_manager->CreateSyntheticObject(sp_ctx.Get(), &result));
+
+  auto sp_iterator{WRL::Make<StackFrames>()};
+
+  RETURN_IF_FAIL(result->SetConcept(
+      __uuidof(IIndexableConcept),
+      static_cast<IIndexableConcept*>(sp_iterator.Get()), nullptr));
+  RETURN_IF_FAIL(result->SetConcept(
+      __uuidof(IIterableConcept),
+      static_cast<IIterableConcept*>(sp_iterator.Get()), nullptr));
+
+  *pp_result = result.Detach();
+  if (pp_metadata) {
+    *pp_metadata = nullptr;
+  }
+  return S_OK;
+}
+
+FrameData::FrameData() = default;
+FrameData::~FrameData() = default;
+FrameData::FrameData(const FrameData&) = default;
+FrameData::FrameData(FrameData&&) = default;
+FrameData& FrameData::operator=(const FrameData&) = default;
+FrameData& FrameData::operator=(FrameData&&) = default;
+
+StackFrameIterator::StackFrameIterator(
+    WRL::ComPtr<IDebugHostContext>& host_context)
+    : sp_ctx_(host_context) {}
+StackFrameIterator::~StackFrameIterator() = default;
+
+HRESULT StackFrameIterator::PopulateFrameData() {
+  frames_.clear();
+  WRL::ComPtr<IModelObject> sp_frames;
+
+  RETURN_IF_FAIL(GetJSStackFrames(sp_frames));
+
+  // Iterate over the array of frames.
+  WRL::ComPtr<IIterableConcept> sp_iterable;
+  RETURN_IF_FAIL(
+      sp_frames->GetConcept(__uuidof(IIterableConcept), &sp_iterable, nullptr));
+
+  WRL::ComPtr<IModelIterator> sp_frame_iterator;
+  RETURN_IF_FAIL(sp_iterable->GetIterator(sp_frames.Get(), &sp_frame_iterator));
+
+  // Loop through all the frames in the array.
+  WRL::ComPtr<IModelObject> sp_frame;
+  while (sp_frame_iterator->GetNext(&sp_frame, 0, nullptr, nullptr) !=
+         E_BOUNDS) {
+    // Skip non-JS frame (frame that doesn't have a function_name).
+    WRL::ComPtr<IModelObject> sp_local_variables;
+    HRESULT hr =
+        sp_frame->GetKeyValue(L"LocalVariables", &sp_local_variables, nullptr);
+    if (FAILED(hr)) continue;
+
+    WRL::ComPtr<IModelObject> sp_currently_executing_jsfunction;
+    hr = sp_local_variables->GetKeyValue(L"currently_executing_jsfunction",
+                                         &sp_currently_executing_jsfunction,
+                                         nullptr);
+    if (FAILED(hr)) continue;
+
+    WRL::ComPtr<IModelObject> sp_function_name, sp_script_name,
+        sp_script_source, sp_function_character_offset;
+    RETURN_IF_FAIL(sp_local_variables->GetKeyValue(L"script_name",
+                                                   &sp_script_name, nullptr));
+    RETURN_IF_FAIL(sp_local_variables->GetKeyValue(L"script_source",
+                                                   &sp_script_source, nullptr));
+    RETURN_IF_FAIL(sp_local_variables->GetKeyValue(L"function_name",
+                                                   &sp_function_name, nullptr));
+    RETURN_IF_FAIL(sp_local_variables->GetKeyValue(
+        L"function_character_offset", &sp_function_character_offset, nullptr));
+
+    FrameData frame_entry;
+    frame_entry.script_name = sp_script_name;
+    frame_entry.script_source = sp_script_source;
+    frame_entry.function_name = sp_function_name;
+    frame_entry.function_character_offset = sp_function_character_offset;
+    frames_.push_back(frame_entry);
+  }
+
+  return S_OK;
+}
+
+IFACEMETHODIMP StackFrameIterator::Reset() noexcept {
+  position_ = 0;
+  return S_OK;
+}
+
+IFACEMETHODIMP StackFrameIterator::GetNext(IModelObject** object,
+                                           ULONG64 dimensions,
+                                           IModelObject** indexers,
+                                           IKeyStore** metadata) noexcept {
+  if (dimensions > 1) return E_INVALIDARG;
+
+  if (position_ == 0) {
+    RETURN_IF_FAIL(PopulateFrameData());
+  }
+
+  if (metadata != nullptr) *metadata = nullptr;
+
+  WRL::ComPtr<IModelObject> sp_index, sp_value;
+
+  if (dimensions == 1) {
+    RETURN_IF_FAIL(CreateULong64(position_, &sp_index));
+  }
+
+  RETURN_IF_FAIL(GetAt(position_, &sp_value));
+
+  // Now update counter and transfer ownership of results, because nothing can
+  // fail from this point onward.
+  ++position_;
+  if (dimensions == 1) {
+    *indexers = sp_index.Detach();
+  }
+  *object = sp_value.Detach();
+  return S_OK;
+}
+
+HRESULT StackFrameIterator::GetAt(uint64_t index, IModelObject** result) const {
+  if (index >= frames_.size()) return E_BOUNDS;
+
+  // Create the synthetic object representing the frame here.
+  const FrameData& curr_frame = frames_.at(index);
+  WRL::ComPtr<IModelObject> sp_value;
+  RETURN_IF_FAIL(
+      sp_data_model_manager->CreateSyntheticObject(sp_ctx_.Get(), &sp_value));
+  RETURN_IF_FAIL(
+      sp_value->SetKey(L"script_name", curr_frame.script_name.Get(), nullptr));
+  RETURN_IF_FAIL(sp_value->SetKey(L"script_source",
+                                  curr_frame.script_source.Get(), nullptr));
+  RETURN_IF_FAIL(sp_value->SetKey(L"function_name",
+                                  curr_frame.function_name.Get(), nullptr));
+  RETURN_IF_FAIL(sp_value->SetKey(L"function_character_offset",
+                                  curr_frame.function_character_offset.Get(),
+                                  nullptr));
+
+  *result = sp_value.Detach();
+  return S_OK;
+}
+
+StackFrames::StackFrames() = default;
+StackFrames::~StackFrames() = default;
+
+IFACEMETHODIMP StackFrames::GetDimensionality(
+    IModelObject* context_object, ULONG64* dimensionality) noexcept {
+  *dimensionality = 1;
+  return S_OK;
+}
+
+IFACEMETHODIMP StackFrames::GetAt(IModelObject* context_object,
+                                  ULONG64 indexer_count,
+                                  IModelObject** indexers,
+                                  IModelObject** object,
+                                  IKeyStore** metadata) noexcept {
+  if (indexer_count != 1) return E_INVALIDARG;
+  if (metadata != nullptr) *metadata = nullptr;
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
+
+  // This should be instantiated once for each synthetic object returned,
+  // so should be able to cache/reuse an iterator.
+  if (opt_frames_ == nullptr) {
+    opt_frames_ = WRL::Make<StackFrameIterator>(sp_ctx);
+    _ASSERT(opt_frames_ != nullptr);
+    RETURN_IF_FAIL(opt_frames_->PopulateFrameData());
+  }
+
+  uint64_t index;
+  RETURN_IF_FAIL(UnboxULong64(indexers[0], &index, true /*convert*/));
+
+  return opt_frames_->GetAt(index, object);
+}
+
+IFACEMETHODIMP StackFrames::SetAt(IModelObject* context_object,
+                                  ULONG64 indexer_count,
+                                  IModelObject** indexers,
+                                  IModelObject* value) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP StackFrames::GetDefaultIndexDimensionality(
+    IModelObject* context_object, ULONG64* dimensionality) noexcept {
+  *dimensionality = 1;
+  return S_OK;
+}
+
+IFACEMETHODIMP StackFrames::GetIterator(IModelObject* context_object,
+                                        IModelIterator** iterator) noexcept {
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
+  auto sp_memory_iterator{WRL::Make<StackFrameIterator>(sp_ctx)};
+  *iterator = sp_memory_iterator.Detach();
+  return S_OK;
+}

tools/v8windbg/src/js-stack.h

@@ -0,0 +1,98 @@
+// Copyright 2021 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.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_JS_STACK_H_
+#define V8_TOOLS_V8WINDBG_SRC_JS_STACK_H_
+
+#include <crtdbg.h>
+#include <wrl/implements.h>
+
+#include <string>
+#include <vector>
+
+#include "src/base/optional.h"
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/v8-debug-helper-interop.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+class JSStackAlias
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelMethod> {
+ public:
+  IFACEMETHOD(Call)
+  (IModelObject* p_context_object, ULONG64 arg_count,
+   _In_reads_(arg_count) IModelObject** pp_arguments, IModelObject** pp_result,
+   IKeyStore** pp_metadata);
+};
+
+struct FrameData {
+  FrameData();
+  ~FrameData();
+  FrameData(const FrameData&);
+  FrameData(FrameData&&);
+  FrameData& operator=(const FrameData&);
+  FrameData& operator=(FrameData&&);
+  WRL::ComPtr<IModelObject> script_name;
+  WRL::ComPtr<IModelObject> script_source;
+  WRL::ComPtr<IModelObject> function_name;
+  WRL::ComPtr<IModelObject> function_character_offset;
+};
+
+class StackFrameIterator
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelIterator> {
+ public:
+  StackFrameIterator(WRL::ComPtr<IDebugHostContext>& host_context);
+  ~StackFrameIterator() override;
+
+  HRESULT PopulateFrameData();
+
+  IFACEMETHOD(Reset)();
+
+  IFACEMETHOD(GetNext)
+  (IModelObject** object, ULONG64 dimensions, IModelObject** indexers,
+   IKeyStore** metadata);
+
+  HRESULT GetAt(uint64_t index, IModelObject** result) const;
+
+ private:
+  ULONG position_ = 0;
+  std::vector<FrameData> frames_;
+  WRL::ComPtr<IDebugHostContext> sp_ctx_;
+};
+
+class StackFrames
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IIndexableConcept, IIterableConcept> {
+ public:
+  StackFrames();
+  ~StackFrames() override;
+
+  // IIndexableConcept members
+  IFACEMETHOD(GetDimensionality)
+  (IModelObject* context_object, ULONG64* dimensionality);
+
+  IFACEMETHOD(GetAt)
+  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
+   IModelObject** object, IKeyStore** metadata);
+
+  IFACEMETHOD(SetAt)
+  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
+   IModelObject* value);
+
+  // IIterableConcept
+  IFACEMETHOD(GetDefaultIndexDimensionality)
+  (IModelObject* context_object, ULONG64* dimensionality);
+
+  IFACEMETHOD(GetIterator)
+  (IModelObject* context_object, IModelIterator** iterator);
+
+ private:
+  WRL::ComPtr<StackFrameIterator> opt_frames_;
+};
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_JS_STACK_H_

tools/v8windbg/src/v8windbg-extension.cc

@@ -8,12 +8,14 @@
 
 #include "tools/v8windbg/base/utilities.h"
 #include "tools/v8windbg/src/cur-isolate.h"
+#include "tools/v8windbg/src/js-stack.h"
 #include "tools/v8windbg/src/list-chunks.h"
 #include "tools/v8windbg/src/local-variables.h"
 #include "tools/v8windbg/src/object-inspection.h"
 
 std::unique_ptr<Extension> Extension::current_extension_ = nullptr;
 const wchar_t* pcur_isolate = L"curisolate";
+const wchar_t* pjs_stack = L"jsstack";
 const wchar_t* plist_chunks = L"listchunks";
 const wchar_t* pv8_object = L"v8object";
 
@@ -260,6 +262,7 @@ HRESULT Extension::Initialize() {
   // Register all function aliases.
   std::vector<std::pair<const wchar_t*, WRL::ComPtr<IModelMethod>>> functions =
       {{pcur_isolate, WRL::Make<CurrIsolateAlias>()},
+       {pjs_stack, WRL::Make<JSStackAlias>()},
        {plist_chunks, WRL::Make<ListChunksAlias>()},
        {pv8_object, WRL::Make<InspectV8ObjectMethod>()}};
   for (const auto& function : functions) {
@@ -371,6 +374,7 @@ Extension::RegistrationType& Extension::RegistrationType::operator=(
 
 Extension::~Extension() {
   sp_debug_host_extensibility->DestroyFunctionAlias(pcur_isolate);
+  sp_debug_host_extensibility->DestroyFunctionAlias(pjs_stack);
   sp_debug_host_extensibility->DestroyFunctionAlias(plist_chunks);
   sp_debug_host_extensibility->DestroyFunctionAlias(pv8_object);
 

tools/v8windbg/test/v8windbg-test.cc

@@ -226,12 +226,26 @@ void RunTests() {
       "dx object.Value.map.instance_descriptors.descriptors[1].key",
       {"\"secondProp\"", "SeqOneByteString"}, &output, p_debug_control.Get());
 
-  RunAndCheckOutput(
-      "local variables",
-      "dx -r1 @$curthread.Stack.Frames.Where(f => "
-      "f.ToDisplayString().Contains(\"InterpreterEntryTrampoline\")).Skip(1)."
-      "First().LocalVariables.@\"memory interpreted as Objects\"",
-      {"\"hello\""}, &output, p_debug_control.Get());
+  // TODO(v8:11527): enable this when symbol information for the in-Isolate
+  // builtins is available.
+  // RunAndCheckOutput(
+  //     "local variables",
+  //     "dx -r1 @$curthread.Stack.Frames.Where(f => "
+  //     "f.ToDisplayString().Contains(\"InterpreterEntryTrampoline\")).Skip(1)."
+  //     "First().LocalVariables.@\"memory interpreted as Objects\"",
+  //     {"\"hello\""}, &output, p_debug_control.Get());
+
+  RunAndCheckOutput("js stack", "dx @$jsstack()[0].function_name",
+                    {"\"a\"", "SeqOneByteString"}, &output,
+                    p_debug_control.Get());
+
+  RunAndCheckOutput("js stack", "dx @$jsstack()[1].function_name",
+                    {"\"b\"", "SeqOneByteString"}, &output,
+                    p_debug_control.Get());
+
+  RunAndCheckOutput("js stack", "dx @$jsstack()[2].function_name",
+                    {"empty_string \"\"", "SeqOneByteString"}, &output,
+                    p_debug_control.Get());
 
   // Detach before exiting
   hr = p_client->DetachProcesses();