[Cleanup] Remove some unused functions and variables from ParseInfo.

Removes some unused functions in ParseInfo and makes the associated fields unique_ptr instead
of shared_ptr. Also removes an unused zone in Compiler.

Change-Id: Idf1fbfb523cfc2b9a265d2855b1167770203cfd5
Reviewed-on: https://chromium-review.googlesource.com/1185193
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55342}

src/compiler.cc

@@ -1654,7 +1654,6 @@ MaybeHandle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
               natives);
 
     // Compile the function and add it to the isolate cache.
-    Zone compile_zone(isolate->allocator(), ZONE_NAME);
     if (origin_options.IsModule()) parse_info.set_module();
     parse_info.set_extension(extension);
     parse_info.set_eager(compile_options == ScriptCompiler::kEagerCompile);

src/parsing/parse-info.cc

@@ -7,6 +7,7 @@
 #include "src/ast/ast-source-ranges.h"
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/ast.h"
+#include "src/base/template-utils.h"
 #include "src/heap/heap-inl.h"
 #include "src/objects-inl.h"
 #include "src/objects/scope-info.h"
@@ -16,7 +17,7 @@ namespace v8 {
 namespace internal {
 
 ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
-    : zone_(std::make_shared<Zone>(zone_allocator, ZONE_NAME)),
+    : zone_(base::make_unique<Zone>(zone_allocator, ZONE_NAME)),
       flags_(0),
       extension_(nullptr),
       script_scope_(nullptr),
@@ -130,11 +131,6 @@ void ParseInfo::UpdateBackgroundParseStatisticsOnMainThread(Isolate* isolate) {
   set_runtime_call_stats(main_call_stats);
 }
 
-void ParseInfo::ShareZone(ParseInfo* other) {
-  DCHECK_EQ(0, zone_->allocation_size());
-  zone_ = other->zone_;
-}
-
 Handle<Script> ParseInfo::CreateScript(Isolate* isolate, Handle<String> source,
                                        ScriptOriginOptions origin_options,
                                        NativesFlag natives) {
@@ -175,11 +171,6 @@ AstValueFactory* ParseInfo::GetOrCreateAstValueFactory() {
   return ast_value_factory();
 }
 
-void ParseInfo::ShareAstValueFactory(ParseInfo* other) {
-  DCHECK(!ast_value_factory_.get());
-  ast_value_factory_ = other->ast_value_factory_;
-}
-
 void ParseInfo::AllocateSourceRangeMap() {
   DCHECK(block_coverage_enabled());
   set_source_range_map(new (zone()) SourceRangeMap(zone()));

src/parsing/parse-info.h

@@ -54,12 +54,6 @@ class V8_EXPORT_PRIVATE ParseInfo {
 
   Zone* zone() const { return zone_.get(); }
 
-  // Sets this parse info to share the same zone as |other|
-  void ShareZone(ParseInfo* other);
-
-  // Sets this parse info to share the same ast value factory as |other|
-  void ShareAstValueFactory(ParseInfo* other);
-
 // Convenience accessor methods for flags.
 #define FLAG_ACCESSOR(flag, getter, setter)     \
   bool getter() const { return GetFlag(flag); } \
@@ -253,7 +247,7 @@ class V8_EXPORT_PRIVATE ParseInfo {
   };
 
   //------------- Inputs to parsing and scope analysis -----------------------
-  std::shared_ptr<Zone> zone_;
+  std::unique_ptr<Zone> zone_;
   unsigned flags_;
   v8::Extension* extension_;
   DeclarationScope* script_scope_;
@@ -275,7 +269,7 @@ class V8_EXPORT_PRIVATE ParseInfo {
   //----------- Inputs+Outputs of parsing and scope analysis -----------------
   std::unique_ptr<Utf16CharacterStream> character_stream_;
   ConsumedPreParsedScopeData consumed_preparsed_scope_data_;
-  std::shared_ptr<AstValueFactory> ast_value_factory_;
+  std::unique_ptr<AstValueFactory> ast_value_factory_;
   const class AstStringConstants* ast_string_constants_;
   const AstRawString* function_name_;
   RuntimeCallStats* runtime_call_stats_;
@@ -284,7 +278,6 @@ class V8_EXPORT_PRIVATE ParseInfo {
 
   //----------- Output of parsing and scope analysis ------------------------
   FunctionLiteral* literal_;
-  std::shared_ptr<DeferredHandles> deferred_handles_;
   PendingCompilationErrorHandler pending_error_handler_;
 
   void SetFlag(Flag f) { flags_ |= f; }