Expose a proxy object to evaluateOnCallFrame for WebAssembly

When debugging WebAssembly, calls to evaluateOnCallFrame always return
undefined. This CL enables evaluateOnCallFrame for WebAssembly and
creates a proxy object that is injected into the evaluation context.

Bug: chromium:1127914
Change-Id: I3f5cff3be2c9de45c7b1f3f7ed4fc2e1cc545ac6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2429265
Commit-Queue: Philip Pfaffe <pfaffe@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70315}

src/debug/debug-evaluate.cc

@@ -18,6 +18,7 @@
 #include "src/objects/contexts.h"
 #include "src/snapshot/snapshot.h"
 #include "src/wasm/wasm-debug.h"
+#include "src/wasm/wasm-js.h"
 
 namespace v8 {
 namespace internal {
@@ -106,6 +107,9 @@ V8_EXPORT MaybeHandle<Object> DebugEvaluate::WebAssembly(
 
   StackTraceFrameIterator it(isolate, frame_id);
   if (!it.is_wasm()) return isolate->factory()->undefined_value();
+  WasmFrame* frame = WasmFrame::cast(it.frame());
+
+  Handle<JSProxy> context_extension = WasmJs::GetJSDebugProxy(frame);
 
   DisableBreak disable_break_scope(isolate->debug(), /*disable=*/true);
 
@@ -114,12 +118,14 @@ V8_EXPORT MaybeHandle<Object> DebugEvaluate::WebAssembly(
     return {};
   }
 
-  Handle<Context> context = isolate->native_context();
-  Handle<JSObject> receiver(context->global_proxy(), isolate);
+  Handle<ScopeInfo> scope_info =
+      ScopeInfo::CreateForWithScope(isolate, Handle<ScopeInfo>::null());
+  Handle<Context> context = isolate->factory()->NewWithContext(
+      isolate->native_context(), scope_info, context_extension);
 
   Handle<Object> result;
-  if (!DebugEvaluate::Evaluate(isolate, shared_info, context, receiver, source,
-                               throw_on_side_effect)
+  if (!DebugEvaluate::Evaluate(isolate, shared_info, context, context_extension,
+                               source, throw_on_side_effect)
            .ToHandle(&result)) {
     return {};
   }

src/wasm/wasm-debug.cc

@@ -340,6 +340,12 @@ class DebugInfoImpl {
                     debug_break_fp);
   }
 
+  const WasmFunction& GetFunctionAtAddress(Address pc) {
+    FrameInspectionScope scope(this, pc);
+    auto* module = native_module_->module();
+    return module->functions[scope.code->index()];
+  }
+
   Handle<JSObject> GetLocalScopeObject(Isolate* isolate, Address pc, Address fp,
                                        Address debug_break_fp) {
     FrameInspectionScope scope(this, pc);
@@ -909,6 +915,10 @@ WasmValue DebugInfo::GetStackValue(int index, Address pc, Address fp,
   return impl_->GetStackValue(index, pc, fp, debug_break_fp);
 }
 
+const wasm::WasmFunction& DebugInfo::GetFunctionAtAddress(Address pc) {
+  return impl_->GetFunctionAtAddress(pc);
+}
+
 Handle<JSObject> DebugInfo::GetLocalScopeObject(Isolate* isolate, Address pc,
                                                 Address fp,
                                                 Address debug_break_fp) {

src/wasm/wasm-debug.h

@@ -34,6 +34,7 @@ class NativeModule;
 class WasmCode;
 class WireBytesRef;
 class WasmValue;
+struct WasmFunction;
 
 // Side table storing information used to inspect Liftoff frames at runtime.
 // This table is only created on demand for debugging, so it is not optimized
@@ -153,6 +154,9 @@ class V8_EXPORT_PRIVATE DebugInfo {
   WasmValue GetLocalValue(int local, Address pc, Address fp,
                           Address debug_break_fp);
   int GetStackDepth(Address pc);
+
+  const wasm::WasmFunction& GetFunctionAtAddress(Address pc);
+
   WasmValue GetStackValue(int index, Address pc, Address fp,
                           Address debug_break_fp);
 

src/wasm/wasm-js.h

@@ -9,6 +9,8 @@
 
 namespace v8 {
 namespace internal {
+class JSProxy;
+class WasmFrame;
 
 namespace wasm {
 class StreamingDecoder;
@@ -19,6 +21,8 @@ class WasmJs {
  public:
   V8_EXPORT_PRIVATE static void Install(Isolate* isolate,
                                         bool exposed_on_global_object);
+
+  V8_EXPORT_PRIVATE static Handle<JSProxy> GetJSDebugProxy(WasmFrame* frame);
 };
 
 }  // namespace internal

test/cctest/wasm/test-wasm-debug-evaluate.cc

@@ -525,15 +525,37 @@ WASM_COMPILED_EXEC_TEST(WasmDebugEvaluate_JavaScript) {
   uint16_t index = 0;
   runner.builder().AddIndirectFunctionTable(&index, 1);
 
-  TestCode<int> code(
+  TestCode<int64_t> code(
       &runner,
       {WASM_SET_GLOBAL(0, WASM_I32V_2('B')),
-       WASM_SET_LOCAL(0, WASM_I32V_2('A')), WASM_RETURN1(WASM_GET_LOCAL(0))},
-      {ValueType::kI32});
+       WASM_SET_LOCAL(0, WASM_I64V_2('A')), WASM_RETURN1(WASM_GET_LOCAL(0))},
+      {ValueType::kI64});
   code.BreakOnReturn(&runner);
 
   Isolate* isolate = runner.main_isolate();
-  Handle<String> snippet = V8String(isolate, "213");
+  Handle<String> snippet =
+      V8String(isolate,
+               "JSON.stringify(["
+               //"$global0, "
+               //"$table0, "
+               "$var0, "
+               //"$main, "
+               //"$memory0, "
+               //"globals[0], "
+               //"tables[0], "
+               "locals[0], "
+               //"functions[0], "
+               //"memories[0], "
+               //"memories, "
+               //"tables, "
+               //"stack, "
+               //"imports, "
+               //"exports, "
+               //"globals, "
+               "locals, "
+               //"functions, "
+               "], (k, v) => k === 'at' || typeof v === 'undefined' || typeof "
+               "v === 'object' ? v : v.toString())");
 
   WasmJSBreakHandler break_handler(isolate, snippet);
   CHECK(!code.Run(&runner).is_null());
@@ -541,7 +563,10 @@ WASM_COMPILED_EXEC_TEST(WasmDebugEvaluate_JavaScript) {
   WasmJSBreakHandler::EvaluationResult result =
       break_handler.result().ToChecked();
   CHECK_WITH_MSG(result.error.IsNothing(), result.error.ToChecked().c_str());
-  CHECK_EQ(result.result.ToChecked(), "213");
+  CHECK_EQ(result.result.ToChecked(), "[\"65\",\"65\",{}]");
+  //"[\"66\",{},\"65\",\"function 0() { [native code] }\",{},"
+  //"\"66\",{},\"65\",\"function 0() { [native code] }\",{},"
+  //"{},{},{\"0\":\"65\"},{},{},{},{},{}]");
 }
 
 }  // namespace