[wasm] Remove TurbofanWasmCompilationUnit::ok_ field

This field is redundant in that {ok_ == true} equals
{wasm_code_ != nullptr}. Thus remove it, and simplify some logic.

R=ahaas@chromium.org
CC=gdeepti@chromium.org

Bug: v8:8238
Change-Id: I3e3cfcc3a06c945d836c1a8a388bec54e1af12ea
Reviewed-on: https://chromium-review.googlesource.com/c/1290791Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56803}

src/compiler/wasm-compiler.cc

@@ -5209,8 +5209,6 @@ void TurbofanWasmCompilationUnit::ExecuteCompilation(
   double decode_ms = 0;
   size_t node_count = 0;
 
-  // Scope for the {graph_zone}.
-  {
   Zone graph_zone(wasm_unit_->wasm_engine_->allocator(), ZONE_NAME);
   MachineGraph* mcgraph = new (&graph_zone)
       MachineGraph(new (&graph_zone) Graph(&graph_zone),
@@ -5241,10 +5239,7 @@ void TurbofanWasmCompilationUnit::ExecuteCompilation(
   SourcePositionTable* source_positions =
       BuildGraphForWasmFunction(detected, &decode_ms, mcgraph, node_origins);
 
-    if (graph_construction_result_.failed()) {
-      ok_ = false;
-      return;
-    }
+  if (graph_construction_result_.failed()) return;
 
   if (node_origins) {
     node_origins->AddDecorator();
@@ -5264,14 +5259,13 @@ void TurbofanWasmCompilationUnit::ExecuteCompilation(
         GetI32WasmCallDescriptor(&compilation_zone, call_descriptor);
   }
 
-    std::unique_ptr<OptimizedCompilationJob> job(
-        Pipeline::NewWasmCompilationJob(
+  std::unique_ptr<OptimizedCompilationJob> job(Pipeline::NewWasmCompilationJob(
       &info, wasm_unit_->wasm_engine_, mcgraph, call_descriptor,
       source_positions, node_origins, wasm_unit_->func_body_,
       const_cast<wasm::WasmModule*>(wasm_unit_->env_->module),
       wasm_unit_->native_module_, wasm_unit_->func_index_,
       wasm_unit_->env_->module->origin));
-    ok_ = job->ExecuteJob() == CompilationJob::SUCCEEDED;
+  bool succeeded = job->ExecuteJob() == CompilationJob::SUCCEEDED;
   // TODO(bradnelson): Improve histogram handling of size_t.
   wasm_unit_->counters_->wasm_compile_function_peak_memory_bytes()->AddSample(
       static_cast<int>(mcgraph->graph()->zone()->allocation_size()));
@@ -5285,20 +5279,22 @@ void TurbofanWasmCompilationUnit::ExecuteCompilation(
                               wasm_unit_->func_body_.start),
         decode_ms, node_count, pipeline_ms);
   }
-    if (ok_) wasm_code_ = info.wasm_code();
+  if (succeeded) {
+    wasm_code_ = info.wasm_code();
+    wasm_unit_->native_module()->PublishCode(wasm_code_);
   }
-  if (ok_) wasm_unit_->native_module()->PublishCode(wasm_code_);
 }
 
 wasm::WasmCode* TurbofanWasmCompilationUnit::FinishCompilation(
     wasm::ErrorThrower* thrower) {
-  if (!ok_) {
+  DCHECK_IMPLIES(graph_construction_result_.failed(), wasm_code_ == nullptr);
+  if (wasm_code_ != nullptr) return wasm_code_;
+
   if (graph_construction_result_.failed()) {
     // Add the function as another context for the exception. This is
     // user-visible, so use official format.
     EmbeddedVector<char, 128> message;
-      wasm::ModuleWireBytes wire_bytes(
-          wasm_unit_->native_module()->wire_bytes());
+    wasm::ModuleWireBytes wire_bytes(wasm_unit_->native_module()->wire_bytes());
     wasm::WireBytesRef name_ref =
         wasm_unit_->native_module()->module()->LookupFunctionName(
             wire_bytes, wasm_unit_->func_index_);
@@ -5307,16 +5303,13 @@ wasm::WasmCode* TurbofanWasmCompilationUnit::FinishCompilation(
       SNPrintF(message, "Compiling wasm function \"%.*s\" failed",
                name.length(), name.start());
     } else {
-        SNPrintF(message,
-                 "Compiling wasm function \"wasm-function[%d]\" failed",
+      SNPrintF(message, "Compiling wasm function \"wasm-function[%d]\" failed",
                wasm_unit_->func_index_);
     }
     thrower->CompileFailed(message.start(), graph_construction_result_);
   }
 
   return nullptr;
-  }
-  return wasm_code_;
 }
 
 namespace {

src/compiler/wasm-compiler.h

@@ -61,7 +61,6 @@ class TurbofanWasmCompilationUnit {
 
  private:
   wasm::WasmCompilationUnit* const wasm_unit_;
-  bool ok_ = true;
   wasm::WasmCode* wasm_code_ = nullptr;
   wasm::Result<wasm::DecodeStruct*> graph_construction_result_;