[wasm] fix clear context group for wasm

This CL only clears the wasm translations that correspond to the context
group being reset instead of clearing all.

R=clemensh@chromium.org,kozyatinskiy@chromium.org
BUG=chromium:892864

Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ib5af0489cbdb7c9b1571cb9cf935fda3bee14015
Reviewed-on: https://chromium-review.googlesource.com/c/1292676Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Commit-Queue: Aseem Garg <aseemgarg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57302}

src/inspector/v8-inspector-impl.cc

@@ -247,10 +247,15 @@ void V8InspectorImpl::contextCollected(int groupId, int contextId) {
 void V8InspectorImpl::resetContextGroup(int contextGroupId) {
   m_consoleStorageMap.erase(contextGroupId);
   m_muteExceptionsMap.erase(contextGroupId);
+  std::vector<int> contextIdsToClear;
+  forEachContext(contextGroupId,
+                 [&contextIdsToClear](InspectedContext* context) {
+                   contextIdsToClear.push_back(context->contextId());
+                 });
+  m_debugger->wasmTranslation()->Clear(m_isolate, contextIdsToClear);
   forEachSession(contextGroupId,
                  [](V8InspectorSessionImpl* session) { session->reset(); });
   m_contexts.erase(contextGroupId);
-  m_debugger->wasmTranslation()->Clear();
 }
 
 void V8InspectorImpl::idleStarted() { m_isolate->SetIdle(true); }

src/inspector/wasm-translation.cc

@@ -175,6 +175,12 @@ class WasmTranslation::TranslatorImpl {
     return builder.toString();
   }
 
+  int GetContextId(v8::Isolate* isolate) {
+    v8::HandleScope scope(isolate);
+    v8::Local<v8::debug::WasmScript> script = script_.Get(isolate);
+    return script->ContextId().FromMaybe(0);
+  }
+
  private:
   String16 GetFakeScriptUrl(v8::Isolate* isolate, int func_index) {
     v8::Local<v8::debug::WasmScript> script = script_.Get(isolate);
@@ -267,6 +273,32 @@ void WasmTranslation::Clear() {
   fake_scripts_.clear();
 }
 
+void WasmTranslation::Clear(v8::Isolate* isolate,
+                            const std::vector<int>& contextIdsToClear) {
+  for (auto iter = fake_scripts_.begin(); iter != fake_scripts_.end();) {
+    auto contextId = iter->second->GetContextId(isolate);
+    auto it = std::find(std::begin(contextIdsToClear),
+                        std::end(contextIdsToClear), contextId);
+    if (it != std::end(contextIdsToClear)) {
+      iter = fake_scripts_.erase(iter);
+    } else {
+      ++iter;
+    }
+  }
+
+  for (auto iter = wasm_translators_.begin();
+       iter != wasm_translators_.end();) {
+    auto contextId = iter->second->GetContextId(isolate);
+    auto it = std::find(std::begin(contextIdsToClear),
+                        std::end(contextIdsToClear), contextId);
+    if (it != std::end(contextIdsToClear)) {
+      iter = wasm_translators_.erase(iter);
+    } else {
+      ++iter;
+    }
+  }
+}
+
 const String16& WasmTranslation::GetSource(const String16& script_id,
                                            int func_index) {
   auto it = fake_scripts_.find(script_id);

src/inspector/wasm-translation.h

@@ -32,6 +32,9 @@ class WasmTranslation {
   // Clear all registered scripts.
   void Clear();
 
+  // Clear all registered scripts for context group.
+  void Clear(v8::Isolate* isolate, const std::vector<int>& contextIdsToClear);
+
   // Translate a location as generated by V8 to a location that should be sent
   // over protocol.
   // Does nothing for locations referencing a script which was not registered

test/inspector/debugger/wasm-reset-context-group-expected.txt

+Checks resetting context group with wasm.
+{
+    id : <messageId>
+    result : {
+        result : {
+            description : 3
+            type : number
+            value : 3
+        }
+    }
+}
+{
+    error : {
+        code : -32000
+        message : Cannot find context with specified id
+    }
+    id : <messageId>
+}

test/inspector/debugger/wasm-reset-context-group.js

+// Copyright 2018 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.
+
+InspectorTest.log('Checks resetting context group with wasm.');
+
+utils.load('test/mjsunit/wasm/wasm-constants.js');
+utils.load('test/mjsunit/wasm/wasm-module-builder.js');
+
+var builder = new WasmModuleBuilder();
+
+// wasm_B calls wasm_A <param0> times.
+builder.addFunction('wasm_func', kSig_i_i)
+    .addBody([
+      // clang-format off
+        kExprGetLocal, 0,
+        kExprI32Const, 1,
+        kExprI32Sub,
+      // clang-format on
+    ])
+    .exportAs('main');
+
+
+var module_bytes = builder.toArray();
+
+function instantiate(bytes) {
+  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);
+  // Set global variable.
+  instance = new WebAssembly.Instance(module);
+}
+
+var contextGroup1 = new InspectorTest.ContextGroup();
+var session1 = contextGroup1.connect();
+session1.setupScriptMap();
+
+let contextGroup2 = new InspectorTest.ContextGroup();
+let session2 = contextGroup2.connect();
+session2.setupScriptMap();
+
+(async function test() {
+  await session1.Protocol.Debugger.enable();
+  await session2.Protocol.Debugger.enable();
+
+  session1.Protocol.Runtime.evaluate({
+    expression: `var instance;(${instantiate.toString()})(${JSON.stringify(module_bytes)})`});
+
+  session2.Protocol.Runtime.evaluate({
+    expression: `var instance;(${instantiate.toString()})(${JSON.stringify(module_bytes)})`});
+
+  contextGroup2.reset();
+
+  await session1.Protocol.Debugger.onceScriptParsed(2);
+  InspectorTest.logMessage(await session1.Protocol.Runtime.evaluate({expression: 'instance.exports.main(4)'}));
+  InspectorTest.logMessage(await session2.Protocol.Runtime.evaluate({expression: 'instance.exports.main(5)'}));
+
+  InspectorTest.completeTest();
+})();

test/inspector/inspector-test.cc

@@ -311,6 +311,9 @@ class UtilsExtension : public IsolateData::SetupGlobalTask {
     utils->Set(ToV8String(isolate, "createContextGroup"),
                v8::FunctionTemplate::New(isolate,
                                          &UtilsExtension::CreateContextGroup));
+    utils->Set(
+        ToV8String(isolate, "resetContextGroup"),
+        v8::FunctionTemplate::New(isolate, &UtilsExtension::ResetContextGroup));
     utils->Set(
         ToV8String(isolate, "connectSession"),
         v8::FunctionTemplate::New(isolate, &UtilsExtension::ConnectSession));
@@ -526,6 +529,18 @@ class UtilsExtension : public IsolateData::SetupGlobalTask {
         v8::Int32::New(args.GetIsolate(), context_group_id));
   }
 
+  static void ResetContextGroup(
+      const v8::FunctionCallbackInfo<v8::Value>& args) {
+    if (args.Length() != 1 || !args[0]->IsInt32()) {
+      fprintf(stderr, "Internal error: resetContextGroup(context_group_id).");
+      Exit();
+    }
+    int context_group_id = args[0].As<v8::Int32>()->Value();
+    RunSyncTask(backend_runner_, [&context_group_id](IsolateData* data) {
+      data->ResetContextGroup(context_group_id);
+    });
+  }
+
   static void ConnectSession(const v8::FunctionCallbackInfo<v8::Value>& args) {
     if (args.Length() != 3 || !args[0]->IsInt32() || !args[1]->IsString() ||
         !args[2]->IsFunction()) {

test/inspector/isolate-data.cc

@@ -110,6 +110,10 @@ v8::Local<v8::Context> IsolateData::GetContext(int context_group_id) {
   return contexts_[context_group_id].Get(isolate_.get());
 }
 
+void IsolateData::ResetContextGroup(int context_group_id) {
+  inspector_->resetContextGroup(context_group_id);
+}
+
 int IsolateData::GetContextGroupId(v8::Local<v8::Context> context) {
   return static_cast<int>(
       reinterpret_cast<intptr_t>(

test/inspector/isolate-data.h

@@ -35,6 +35,7 @@ class IsolateData : public v8_inspector::V8InspectorClient {
 
   // Setting things up.
   int CreateContextGroup();
+  void ResetContextGroup(int context_group_id);
   v8::Local<v8::Context> GetContext(int context_group_id);
   int GetContextGroupId(v8::Local<v8::Context> context);
   void RegisterModule(v8::Local<v8::Context> context,

test/inspector/protocol-test.js

@@ -140,6 +140,10 @@ InspectorTest.ContextGroup = class {
     return new InspectorTest.Session(this);
   }
 
+  reset() {
+    utils.resetContextGroup(this.id);
+  }
+
   setupInjectedScriptEnvironment(session) {
     let scriptSource = '';
     let getters = ["length","internalConstructorName","subtype","getProperty",