[wasm-c-api] Add test for traps

Change-Id: I51c25c3e41d11ac2419aac1041fe92192f8fdb9e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1698382
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62688}

src/utils/vector.h

@@ -230,6 +230,8 @@ constexpr Vector<const uint8_t> StaticCharVector(const char (&array)[N]) {
   return Vector<const uint8_t>::cast(Vector<const char>(array, N - 1));
 }
 
+// The resulting vector does not contain a null-termination byte. If you want
+// the null byte, use ArrayVector("foo").
 inline Vector<const char> CStrVector(const char* data) {
   return Vector<const char>(data, strlen(data));
 }
@@ -250,6 +252,9 @@ inline Vector<char> MutableCStrVector(char* data, size_t max) {
   return Vector<char>(data, strnlen(data, max));
 }
 
+// For string literals, ArrayVector("foo") returns a vector ['f', 'o', 'o', \0]
+// with length 4 and null-termination.
+// If you want ['f', 'o', 'o'], use CStrVector("foo").
 template <typename T, size_t N>
 inline constexpr Vector<T> ArrayVector(T (&arr)[N]) {
   return Vector<T>{arr, N};

src/wasm/c-api.cc

@@ -1134,8 +1134,12 @@ auto ExportType::type() const -> const ExternType* {
 
 i::Handle<i::String> VecToString(i::Isolate* isolate,
                                  const vec<byte_t>& chars) {
+  size_t length = chars.size();
+  // Some, but not all, {chars} vectors we get here are null-terminated,
+  // so let's be robust to that.
+  if (length > 0 && chars[length - 1] == 0) length--;
   return isolate->factory()
-      ->NewStringFromUtf8({chars.get(), chars.size()})
+      ->NewStringFromUtf8({chars.get(), length})
       .ToHandleChecked();
 }
 

test/wasm-api-tests/BUILD.gn

@@ -38,6 +38,7 @@ v8_executable("wasm_api_tests") {
     "serialize.cc",
     "table.cc",
     "threads.cc",
+    "traps.cc",
     "wasm-api-test.h",
   ]
 }

test/wasm-api-tests/callbacks.cc

@@ -43,7 +43,7 @@ class WasmCapiCallbacksTest : public WasmCapiTest {
     // Build the following function:
     // int32 stage1(int32 arg0) { return stage2(arg0); }
     uint32_t stage2_index =
-        builder()->AddImport(ArrayVector("stage2"), wasm_i_i_sig());
+        builder()->AddImport(CStrVector("stage2"), wasm_i_i_sig());
     byte code[] = {WASM_CALL_FUNCTION(stage2_index, WASM_GET_LOCAL(0))};
     AddExportedFunction(CStrVector("stage1"), code, sizeof(code));
 
@@ -81,7 +81,7 @@ TEST_F(WasmCapiCallbacksTest, GC) {
   // Build the following function:
   // int32 stage3_to4(int32 arg0) { return stage4(arg0); }
   uint32_t stage4_index =
-      builder()->AddImport(ArrayVector("stage4"), wasm_i_i_sig());
+      builder()->AddImport(CStrVector("stage4"), wasm_i_i_sig());
   byte code[] = {WASM_CALL_FUNCTION(stage4_index, WASM_GET_LOCAL(0))};
   AddExportedFunction(CStrVector("stage3_to4"), code, sizeof(code));
 
@@ -134,7 +134,7 @@ TEST_F(WasmCapiTest, Recursion) {
   //   return fibonacci_c(arg0 - 1) + fibonacci_c(arg0 - 2);
   // }
   uint32_t fibo_c_index =
-      builder()->AddImport(ArrayVector("fibonacci_c"), wasm_i_i_sig());
+      builder()->AddImport(CStrVector("fibonacci_c"), wasm_i_i_sig());
   byte code_fibo[] = {
       WASM_IF(WASM_I32_EQ(WASM_GET_LOCAL(0), WASM_ZERO),
               WASM_RETURN1(WASM_ZERO)),

test/wasm-api-tests/traps.cc

@@ -0,0 +1,60 @@
+// Copyright 2019 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 "test/wasm-api-tests/wasm-api-test.h"
+
+#include <iostream>
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+using ::wasm::Message;
+
+namespace {
+
+own<Trap*> FailCallback(void* env, const Val args[], Val results[]) {
+  Store* store = reinterpret_cast<Store*>(env);
+  Message message = Message::make(std::string("callback abort"));
+  return Trap::make(store, message);
+}
+
+void ExpectMessage(const char* expected, const Message& message) {
+  size_t len = strlen(expected);
+  EXPECT_EQ(len, message.size());
+  EXPECT_EQ(0, strncmp(expected, message.get(), len));
+}
+
+}  // namespace
+
+TEST_F(WasmCapiTest, Traps) {
+  ValueType i32_type[] = {kWasmI32};
+  FunctionSig sig(1, 0, i32_type);
+  uint32_t callback_index = builder()->AddImport(CStrVector("callback"), &sig);
+  byte code[] = {WASM_CALL_FUNCTION0(callback_index)};
+  AddExportedFunction(CStrVector("callback"), code, sizeof(code), &sig);
+  byte code2[] = {WASM_UNREACHABLE, WASM_I32V_1(1)};
+  AddExportedFunction(CStrVector("unreachable"), code2, sizeof(code2), &sig);
+
+  own<FuncType*> func_type = FuncType::make(
+      vec<ValType*>::make(), vec<ValType*>::make(ValType::make(::wasm::I32)));
+  own<Func*> cpp_callback = Func::make(store(), func_type.get(), FailCallback,
+                                       reinterpret_cast<void*>(store()));
+  Extern* imports[] = {cpp_callback.get()};
+  Instantiate(imports);
+
+  Func* cpp_trapping_func = GetExportedFunction(0);
+  own<Trap*> cpp_trap = cpp_trapping_func->call();
+  EXPECT_NE(nullptr, cpp_trap.get());
+  ExpectMessage("Uncaught Error: callback abort", cpp_trap->message());
+
+  Func* wasm_trapping_func = GetExportedFunction(1);
+  own<Trap*> wasm_trap = wasm_trapping_func->call();
+  EXPECT_NE(nullptr, wasm_trap.get());
+  ExpectMessage("Uncaught RuntimeError: unreachable", wasm_trap->message());
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8