[wasm] Add a cctest for the stack on a wasm trap

test/cctest/wasm/test-wasm-stack.cc

Index: test/cctest/wasm/test-wasm-stack.cc
diff --git a/test/cctest/wasm/test-wasm-stack.cc b/test/cctest/wasm/test-wasm-stack.cc
index e34c69703fd24f186237a7c4b4ffe0721a9326f1..3915e43c813d4b774fcb7d02971ac3a52f9be351 100644
--- a/test/cctest/wasm/test-wasm-stack.cc
+++ b/test/cctest/wasm/test-wasm-stack.cc
@@ -51,10 +51,10 @@ struct ExceptionInfo {
 template <int N>
 void CheckExceptionInfos(Isolate* isolate, Handle<Object> exc,
                          const ExceptionInfo (&excInfos)[N]) {
-  // check that it's indeed an Error object
+  // Check that it's indeed an Error object.
   CHECK(Object::IsErrorObject(isolate, exc));
 
-  // extract stack frame from exception
+  // Extract stack frame from the exception.
   Local<v8::Value> localExc = Utils::ToLocal(exc);
   v8::Local<v8::StackTrace> stack = v8::Exception::GetStackTrace(localExc);
   PrintStackTrace(stack);
@@ -76,41 +76,83 @@ TEST(CollectDetailedWasmStack_ExplicitThrowFromJs) {
   TestSignatures sigs;
   TestingModule module;
 
+  // Initialize WasmFunctionCompiler first, since it sets up the HandleScope.
   WasmFunctionCompiler comp1(sigs.v_v(), &module);
 
-  uint32_t jsThrowingIndex = module.AddJsFunction(
+  uint32_t js_throwing_index = module.AddJsFunction(
       sigs.v_v(),
       "(function js() {\n function a() {\n throw new Error(); };\n a(); })");
 
-  BUILD(comp1, WASM_CALL_FUNCTION0(jsThrowingIndex));
-  uint32_t wasmIndex = comp1.CompileAndAdd();
+  BUILD(comp1, WASM_CALL_FUNCTION0(js_throwing_index));
+  uint32_t wasm_index = comp1.CompileAndAdd();
 
   WasmFunctionCompiler comp2(sigs.v_v(), &module);
-  BUILD(comp2, WASM_CALL_FUNCTION0(wasmIndex));
-  uint32_t wasmIndex2 = comp2.CompileAndAdd();
+  BUILD(comp2, WASM_CALL_FUNCTION0(wasm_index));
+  uint32_t wasm_index_2 = comp2.CompileAndAdd();
 
-  Handle<JSFunction> jsWasmWrapper = module.WrapCode(wasmIndex2);
+  Handle<JSFunction> js_wasm_wrapper = module.WrapCode(wasm_index_2);
 
-  Handle<JSFunction> jsTrampoline = Handle<JSFunction>::cast(
+  Handle<JSFunction> js_trampoline = Handle<JSFunction>::cast(
       v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
           CompileRun("(function callFn(fn) { fn(); })"))));
 
-  Isolate* isolate = jsWasmWrapper->GetIsolate();
+  Isolate* isolate = js_wasm_wrapper->GetIsolate();
   isolate->SetCaptureStackTraceForUncaughtExceptions(true, 10,
                                                      v8::StackTrace::kOverview);
   Handle<Object> global(isolate->context()->global_object(), isolate);
-  MaybeHandle<Object> excMaybe;
-  Handle<Object> args[] = {jsWasmWrapper};
+  MaybeHandle<Object> maybe_exc;
+  Handle<Object> args[] = {js_wasm_wrapper};
   MaybeHandle<Object> returnObjMaybe =
-      Execution::TryCall(isolate, jsTrampoline, global, 1, args, &excMaybe);
+      Execution::TryCall(isolate, js_trampoline, global, 1, args, &maybe_exc);
   CHECK(returnObjMaybe.is_null());
 
-  // line number is 1-based, with 0 == kNoLineNumberInfo
-  ExceptionInfo expectedExceptions[] = {
-      {"a", 3},       // comment to prevent clang-format complaints
+  // Line number is 1-based, with 0 == kNoLineNumberInfo.
+  ExceptionInfo expected_exceptions[] = {
+      {"a", 3},       // Comment to prevent clang-format complaints
       {"js", 4},      // -
       {"<WASM>", 0},  // -
       {"<WASM>", 0},  // -
       {"callFn", 1}};
-  CheckExceptionInfos(isolate, excMaybe.ToHandleChecked(), expectedExceptions);
+  CheckExceptionInfos(isolate, maybe_exc.ToHandleChecked(),
+                      expected_exceptions);
+}
+
+// Trigger a trap in WASM, stack should be JS -> WASM -> WASM.
+TEST(CollectDetailedWasmStack_WasmError) {
+  TestSignatures sigs;
+  TestingModule module;
+
+  WasmFunctionCompiler comp1(sigs.i_v(), &module, "exec_unreachable");
+  // Set the execution context, such that a runtime error can be thrown.
+  comp1.SetModuleContext();
+  BUILD(comp1, WASM_UNREACHABLE);
+  uint32_t wasm_index = comp1.CompileAndAdd();
+
+  WasmFunctionCompiler comp2(sigs.i_v(), &module, "call_exec_unreachable");
+  BUILD(comp2, WASM_CALL_FUNCTION0(wasm_index));
+  uint32_t wasm_index_2 = comp2.CompileAndAdd();
+
+  Handle<JSFunction> js_wasm_wrapper = module.WrapCode(wasm_index_2);
+
+  Handle<JSFunction> js_trampoline = Handle<JSFunction>::cast(
+      v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
+          CompileRun("(function callFn(fn) { fn(); })"))));
+
+  Isolate* isolate = js_wasm_wrapper->GetIsolate();
+  isolate->SetCaptureStackTraceForUncaughtExceptions(true, 10,
+                                                     v8::StackTrace::kOverview);
+  Handle<Object> global(isolate->context()->global_object(), isolate);
+  MaybeHandle<Object> maybe_exc;
+  Handle<Object> args[] = {js_wasm_wrapper};
+  MaybeHandle<Object> maybe_return_obj =
+      Execution::TryCall(isolate, js_trampoline, global, 1, args, &maybe_exc);
+  CHECK(maybe_return_obj.is_null());
+
+  // Line number is 1-based, with 0 == kNoLineNumberInfo.
+  ExceptionInfo expected_exceptions[] = {
+      {"<WASM>", 0},  // Comment to prevent clang-format complaints.
+      {"<WASM>", 0},
+      {"callFn", 1}};
+  CheckExceptionInfos(isolate, maybe_exc.ToHandleChecked(),
+                      expected_exceptions);
 }