[cleanup] Clean up CodeReference class

This CL fixes the new {CodeReference} class to comply to the style
guide. It makes it a proper class, renames private fields to end in an
underscore and simplifies the union declaration.

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

Bug: v8:7570
Change-Id: I329bbc6fca1ba3c0cb34fb4e1179eb4fa9044e76
Reviewed-on: https://chromium-review.googlesource.com/1023414Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52722}

src/code-reference.cc

@@ -12,41 +12,41 @@ namespace v8 {
 namespace internal {
 
 Address CodeReference::constant_pool() const {
-  return kind == JS ? code.js->constant_pool() : code.wasm->constant_pool();
+  return kind_ == JS ? js_code_->constant_pool() : wasm_code_->constant_pool();
 }
 
 Address CodeReference::instruction_start() const {
-  return kind == JS
-             ? code.js->InstructionStart()
-             : reinterpret_cast<Address>(code.wasm->instructions().start());
+  return kind_ == JS
+             ? js_code_->InstructionStart()
+             : reinterpret_cast<Address>(wasm_code_->instructions().start());
 }
 
 Address CodeReference::instruction_end() const {
-  return kind == JS
-             ? code.js->InstructionEnd()
-             : reinterpret_cast<Address>(code.wasm->instructions().start() +
-                                         code.wasm->instructions().size());
+  return kind_ == JS
+             ? js_code_->InstructionEnd()
+             : reinterpret_cast<Address>(wasm_code_->instructions().start() +
+                                         wasm_code_->instructions().size());
 }
 
 int CodeReference::instruction_size() const {
-  return kind == JS ? code.js->InstructionSize()
-                    : code.wasm->instructions().length();
+  return kind_ == JS ? js_code_->InstructionSize()
+                     : wasm_code_->instructions().length();
 }
 
 const byte* CodeReference::relocation_start() const {
-  return kind == JS ? code.js->relocation_start()
-                    : code.wasm->reloc_info().start();
+  return kind_ == JS ? js_code_->relocation_start()
+                     : wasm_code_->reloc_info().start();
 }
 
 const byte* CodeReference::relocation_end() const {
-  return kind == JS ? code.js->relocation_end()
-                    : code.wasm->reloc_info().start() +
-                          code.wasm->reloc_info().length();
+  return kind_ == JS ? js_code_->relocation_end()
+                     : wasm_code_->reloc_info().start() +
+                           wasm_code_->reloc_info().length();
 }
 
 int CodeReference::relocation_size() const {
-  return kind == JS ? code.js->relocation_size()
-                    : code.wasm->reloc_info().length();
+  return kind_ == JS ? js_code_->relocation_size()
+                     : wasm_code_->reloc_info().length();
 }
 
 }  // namespace internal

src/code-reference.h

@@ -6,7 +6,7 @@
 #define V8_CODE_REFERENCE_H_
 
 #include "src/handles.h"
-#include "src/objects.h"
+#include "src/objects/code.h"
 
 namespace v8 {
 namespace internal {
@@ -17,10 +17,12 @@ namespace wasm {
 class WasmCode;
 }
 
-struct CodeReference {
-  explicit CodeReference(const wasm::WasmCode* wasm_code = nullptr)
-      : kind(WASM), code(wasm_code) {}
-  explicit CodeReference(Handle<Code> js_code) : kind(JS), code(js_code) {}
+class CodeReference {
+ public:
+  CodeReference() : kind_(JS), js_code_() {}
+  explicit CodeReference(const wasm::WasmCode* wasm_code)
+      : kind_(WASM), wasm_code_(wasm_code) {}
+  explicit CodeReference(Handle<Code> js_code) : kind_(JS), js_code_(js_code) {}
 
   Address constant_pool() const;
   Address instruction_start() const;
@@ -30,22 +32,19 @@ struct CodeReference {
   const byte* relocation_end() const;
   int relocation_size() const;
   bool is_null() const {
-    return kind == JS ? code.js.is_null() : code.wasm == nullptr;
+    return kind_ == JS ? js_code_.is_null() : wasm_code_ == nullptr;
   }
 
  private:
-  enum { JS, WASM } kind;
-  union CodeUnion {
-    explicit CodeUnion(Handle<Code> js_code) : js(js_code) {}
-    explicit CodeUnion(const wasm::WasmCode* wasm_code) : wasm(wasm_code) {}
-    CodeUnion() : wasm(nullptr) {}
+  enum { JS, WASM } kind_;
+  union {
+    const wasm::WasmCode* wasm_code_;
+    Handle<Code> js_code_;
+  };
 
-    const wasm::WasmCode* wasm;
-    Handle<Code> js;
-  } code;
-
-  DISALLOW_NEW_AND_DELETE()
+  DISALLOW_NEW_AND_DELETE();
 };
+ASSERT_TRIVIALLY_COPYABLE(CodeReference);
 
 }  // namespace internal
 }  // namespace v8