[wasm] Add inspector test for stack traces

This ensures that the stack traces show up correctly in
DevTools. I will later extend it for source view.

R=kozyatinskiy@chromium.org, yangguo@chromium.org, titzer@chromium.org
BUG=chromium:613110

Review-Url: https://codereview.chromium.org/2420093002
Cr-Commit-Position: refs/heads/master@{#40392}

test/inspector/debugger/wasm-stack-expected.txt

+Running testFunction with generated WASM bytes...
+Paused on 'debugger;'
+Number of frames: 5
+  - [0] {"functionName":"call_debugger","function_lineNumber":1,"function_columnNumber":24,"lineNumber":2,"columnNumber":4}
+  - [1] {"functionName":"main","lineNumber":0,"columnNumber":1}
+  - [2] {"functionName":"main","lineNumber":0,"columnNumber":1}
+  - [3] {"functionName":"testFunction","function_lineNumber":0,"function_columnNumber":21,"lineNumber":14,"columnNumber":19}
+  - [4] {"functionName":"","function_lineNumber":0,"function_columnNumber":0,"lineNumber":0,"columnNumber":0}
+Getting v8-generated stack trace...
+Result of evaluate (string):
+Error: this is your stack trace:
+    -- skipped --
+    at call_debugger (<anonymous>:3:5)
+    at main (<WASM>[1]+1)
+    at main (<WASM>[2]+1)
+    at testFunction (<anonymous>:15:20)
+    at <anonymous>:1:1
+Finished!

test/inspector/debugger/wasm-stack.js

+// Copyright 2016 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.
+
+// Flags: --expose-wasm
+
+load('test/mjsunit/wasm/wasm-constants.js');
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+var builder = new WasmModuleBuilder();
+
+var imported_idx = builder.addImport("func", kSig_v_v);
+
+var call_imported_idx = builder.addFunction("main", kSig_v_v)
+  .addBody([kExprCallFunction, imported_idx])
+  .index;
+
+builder.addFunction("main", kSig_v_v)
+  .addBody([kExprCallFunction, call_imported_idx])
+  .exportAs("main");
+
+var module_bytes = builder.toArray();
+
+function testFunction(bytes) {
+  function call_debugger() {
+    debugger;
+  }
+
+  var buffer = new ArrayBuffer(bytes.length);
+  var view = new Uint8Array(buffer);
+  for (var i = 0; i < bytes.length; i++) {
+    view[i] = bytes[i] | 0;
+  }
+
+  var module = new WebAssembly.Module(buffer);
+  var instance = new WebAssembly.Instance(module, {func: call_debugger});
+
+  instance.exports.main();
+}
+
+InspectorTest.addScript(testFunction.toString());
+
+Protocol.Debugger.enable();
+Protocol.Debugger.onPaused(handleDebuggerPaused);
+InspectorTest.log('Running testFunction with generated WASM bytes...');
+Protocol.Runtime.evaluate(
+    {'expression': 'testFunction(' + JSON.stringify(module_bytes) + ')'});
+
+function locationToString(callFrame) {
+  var res = {functionName: callFrame.functionName};
+  for (var attr in callFrame.functionLocation) {
+    if (attr == 'scriptId') continue;
+    res['function_'+attr] = callFrame.functionLocation[attr];
+  }
+  for (var attr in callFrame.location) {
+    if (attr == 'scriptId') continue;
+    res[attr] = callFrame.location[attr];
+  }
+  return JSON.stringify(res);
+}
+
+function logStackTrace(messageObject) {
+  var frames = messageObject.params.callFrames;
+  InspectorTest.log('Number of frames: ' + frames.length);
+  for (var i = 0; i < frames.length; ++i) {
+    InspectorTest.log('  - [' + i + '] ' + locationToString(frames[i]));
+  }
+}
+
+function handleDebuggerPaused(messageObject)
+{
+  InspectorTest.log('Paused on \'debugger;\'');
+  logStackTrace(messageObject);
+  InspectorTest.log('Getting v8-generated stack trace...');
+  var topFrameId = messageObject.params.callFrames[0].callFrameId;
+  Protocol.Debugger
+      .evaluateOnCallFrame({
+        callFrameId: topFrameId,
+        expression: '(new Error("this is your stack trace:")).stack'
+      })
+      .then(callbackEvaluate);
+}
+
+function callbackEvaluate(response)
+{
+  InspectorTest.log(
+      'Result of evaluate (' + response.result.result.type + '):');
+  var result_lines = response.result.result.value.split('\n');
+  // Skip the second line, containing the 'evaluate' position.
+  result_lines[1] = '    -- skipped --';
+  InspectorTest.log(result_lines.join('\n'));
+  InspectorTest.log('Finished!');
+  InspectorTest.completeTest();
+}

test/inspector/inspector-test.cc

@@ -33,7 +33,8 @@ class UtilsExtension : public v8::Extension {
       : v8::Extension("v8_inspector/utils",
                       "native function print();"
                       "native function quit();"
-                      "native function setlocale();") {}
+                      "native function setlocale();"
+                      "native function load();") {}
   virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
       v8::Isolate* isolate, v8::Local<v8::String> name) {
     v8::Local<v8::Context> context = isolate->GetCurrentContext();
@@ -54,6 +55,12 @@ class UtilsExtension : public v8::Extension {
                                 .ToLocalChecked())
                    .FromJust()) {
       return v8::FunctionTemplate::New(isolate, UtilsExtension::SetLocale);
+    } else if (name->Equals(context,
+                            v8::String::NewFromUtf8(isolate, "load",
+                                                    v8::NewStringType::kNormal)
+                                .ToLocalChecked())
+                   .FromJust()) {
+      return v8::FunctionTemplate::New(isolate, UtilsExtension::Load);
     }
     return v8::Local<v8::FunctionTemplate>();
   }
@@ -102,6 +109,29 @@ class UtilsExtension : public v8::Extension {
     v8::String::Utf8Value str(args[0]);
     setlocale(LC_NUMERIC, *str);
   }
+
+  static void Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
+    if (args.Length() != 1 || !args[0]->IsString()) {
+      fprintf(stderr, "Internal error: load gets one string argument.");
+      Exit();
+    }
+    v8::String::Utf8Value str(args[0]);
+    v8::Isolate* isolate = args.GetIsolate();
+    bool exists = false;
+    std::string filename(*str, str.length());
+    v8::internal::Vector<const char> chars =
+        v8::internal::ReadFile(filename.c_str(), &exists);
+    if (!exists) {
+      isolate->ThrowException(
+          v8::String::NewFromUtf8(isolate, "Error loading file",
+                                  v8::NewStringType::kNormal)
+              .ToLocalChecked());
+      return;
+    }
+    ExecuteStringTask task(chars);
+    v8::Global<v8::Context> context(isolate, isolate->GetCurrentContext());
+    task.Run(isolate, context);
+  }
 };
 
 class SetTimeoutTask : public TaskRunner::Task {