[turbofan] Add comments to CodeAssembler

src/compiler/code-assembler.cc

 // Copyright 2015 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 "src/compiler/code-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/pipeline.h"
 #include "src/compiler/raw-machine-assembler.h"
 #include "src/compiler/schedule.h"
 #include "src/frames.h"
 #include "src/interface-descriptors.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/machine-type.h"
 #include "src/macro-assembler.h"
+#include "src/utils.h"
 #include "src/zone.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 CodeAssembler::CodeAssembler(Isolate* isolate, Zone* zone,
                              const CallInterfaceDescriptor& descriptor,
                              Code::Flags flags, const char* name,
                              size_t result_size)
@@ skipping 123 matching lines @@
 Node* CodeAssembler::Parameter(int value) {
   return raw_assembler_->Parameter(value);
 }
 
 void CodeAssembler::Return(Node* value) {
   return raw_assembler_->Return(value);
 }
 
 void CodeAssembler::DebugBreak() { raw_assembler_->DebugBreak(); }
 
+void CodeAssembler::Comment(const char* format, ...) {
+  if (!FLAG_code_comments) return;
+  char buffer[4 * KB];
+  StringBuilder builder(buffer, arraysize(buffer));
+  va_list arguments;
+  va_start(arguments, format);
+  builder.AddFormattedList(format, arguments);
+  va_end(arguments);
+
+  // Copy the string before recording it in the assembler to avoid
+  // issues when the stack allocated buffer goes out of scope.
+  size_t length = builder.position() + 3;
+  char* copy = reinterpret_cast<char*>(malloc(static_cast<int>(length)));
+  MemCopy(copy + 2, builder.Finalize(), length);
+  copy[0] = ';';
+  copy[1] = ' ';
+  raw_assembler_->Comment(copy);
+}
+
 void CodeAssembler::Bind(CodeAssembler::Label* label) { return label->Bind(); }
 
 Node* CodeAssembler::LoadFramePointer() {
   return raw_assembler_->LoadFramePointer();
 }
 
 Node* CodeAssembler::LoadParentFramePointer() {
   return raw_assembler_->LoadParentFramePointer();
 }
 
@@ skipping 557 matching lines @@
       }
     }
   }
 
   bound_ = true;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8