[wasm][cleanup] CompileCWasmEntry should never fail

This changes the return type of {CompileCWasmEntry} from a {MaybeHandle}
to {Handle}. All call sites used {ToHandleChecked} anyway, and if
compiling a c-wasm-entry failed, something seriously went wrong. Hence
fail immediately during compilation, instead of returning an empty
handle and then failing later.

R=jkummerow@chromium.org

Change-Id: I19d85e907670c92da74c9a7ab2d9b646682a02cd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2237133
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68279}

src/compiler/wasm-compiler.cc

@@ -6790,8 +6790,7 @@ MaybeHandle<Code> CompileJSToJSWrapper(Isolate* isolate,
   return code;
 }
 
-MaybeHandle<Code> CompileCWasmEntry(Isolate* isolate,
-                                    const wasm::FunctionSig* sig) {
+Handle<Code> CompileCWasmEntry(Isolate* isolate, const wasm::FunctionSig* sig) {
   std::unique_ptr<Zone> zone =
       std::make_unique<Zone>(isolate->allocator(), ZONE_NAME);
   Graph* graph = new (zone.get()) Graph(zone.get());
@@ -6836,14 +6835,11 @@ MaybeHandle<Code> CompileCWasmEntry(Isolate* isolate,
           Code::C_WASM_ENTRY, std::move(name_buffer),
           AssemblerOptions::Default(isolate)));
 
-  if (job->ExecuteJob(isolate->counters()->runtime_call_stats()) ==
-          CompilationJob::FAILED ||
-      job->FinalizeJob(isolate) == CompilationJob::FAILED) {
-    return {};
-  }
-  Handle<Code> code = job->compilation_info()->code();
+  CHECK_NE(job->ExecuteJob(isolate->counters()->runtime_call_stats()),
+           CompilationJob::FAILED);
+  CHECK_NE(job->FinalizeJob(isolate), CompilationJob::FAILED);
 
-  return code;
+  return job->compilation_info()->code();
 }
 
 namespace {

src/compiler/wasm-compiler.h

@@ -138,8 +138,8 @@ enum CWasmEntryParameters {
 
 // Compiles a stub with C++ linkage, to be called from Execution::CallWasm,
 // which knows how to feed it its parameters.
-V8_EXPORT_PRIVATE MaybeHandle<Code> CompileCWasmEntry(Isolate*,
-                                                      const wasm::FunctionSig*);
+V8_EXPORT_PRIVATE Handle<Code> CompileCWasmEntry(Isolate*,
+                                                 const wasm::FunctionSig*);
 
 // Values from the instance object are cached between Wasm-level function calls.
 // This struct allows the SSA environment handling this cache to be defined

src/wasm/c-api.cc

@@ -1375,7 +1375,7 @@ void PrepareFunctionData(i::Isolate* isolate,
   if (!function_data->c_wrapper_code().IsSmi()) return;
   // Compile wrapper code.
   i::Handle<i::Code> wrapper_code =
-      i::compiler::CompileCWasmEntry(isolate, sig).ToHandleChecked();
+      i::compiler::CompileCWasmEntry(isolate, sig);
   function_data->set_c_wrapper_code(*wrapper_code);
   // Compute packed args size.
   function_data->set_packed_args_size(

src/wasm/wasm-debug-evaluate.cc

@@ -353,8 +353,7 @@ Maybe<std::string> DebugEvaluateImpl(
 
   // TODO(wasm): Cache this code.
   Handle<Code> wasm_entry =
-      compiler::CompileCWasmEntry(isolate, entry_point->sig())
-          .ToHandleChecked();
+      compiler::CompileCWasmEntry(isolate, entry_point->sig());
 
   CWasmArgumentsPacker packer(4 /* uint32_t return value, no parameters. */);
   Execution::CallWasm(isolate, wasm_entry, entry_point->GetWasmCallTarget(),

test/cctest/wasm/test-c-wasm-entry.cc

@@ -40,8 +40,7 @@ class CWasmEntryArgTester {
     runner_.Build(code.data(), code.data() + code.size());
     wasm_code_ = runner_.builder().GetFunctionCode(0);
     Handle<WasmInstanceObject> instance(runner_.builder().instance_object());
-    c_wasm_entry_ =
-        compiler::CompileCWasmEntry(isolate_, sig_).ToHandleChecked();
+    c_wasm_entry_ = compiler::CompileCWasmEntry(isolate_, sig_);
   }
 
   template <typename... Rest>