From d9d76b7a5c68100427eea5d4b52fe73b73ba4f08 Mon Sep 17 00:00:00 2001
From: "sanjoy@chromium.org"
 <sanjoy@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Thu, 28 Jun 2012 12:34:51 +0000
Subject: [PATCH] Revert 11939 'Add a CompilationHandleScope' since it breaks
 array-sort.js in Win32 Release.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/10698031

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11943 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/api.cc      | 95 +------------------------------------------------
 src/api.h       | 36 +------------------
 src/compiler.cc | 14 ++------
 src/compiler.h  | 26 --------------
 src/handles.cc  | 41 ---------------------
 src/handles.h   | 30 ----------------
 src/hydrogen.cc |  1 -
 7 files changed, 5 insertions(+), 238 deletions(-)

diff --git a/src/api.cc b/src/api.cc
index dda482ceef..0d88047aa2 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6374,28 +6374,12 @@ char* HandleScopeImplementer::RestoreThread(char* storage) {
 
 
 void HandleScopeImplementer::IterateThis(ObjectVisitor* v) {
-#ifdef DEBUG
-  bool found_block_before_deferred = false;
-#endif
   // Iterate over all handles in the blocks except for the last.
   for (int i = blocks()->length() - 2; i >= 0; --i) {
     Object** block = blocks()->at(i);
-    if (last_handle_before_deferred_block_ != NULL &&
-        (last_handle_before_deferred_block_ < &block[kHandleBlockSize]) &&
-        (last_handle_before_deferred_block_ >= block)) {
-      v->VisitPointers(block, last_handle_before_deferred_block_);
-      ASSERT(!found_block_before_deferred);
-#ifdef DEBUG
-      found_block_before_deferred = true;
-#endif
-    } else {
-      v->VisitPointers(block, &block[kHandleBlockSize]);
-    }
+    v->VisitPointers(block, &block[kHandleBlockSize]);
   }
 
-  ASSERT(last_handle_before_deferred_block_ == NULL ||
-         found_block_before_deferred);
-
   // Iterate over live handles in the last block (if any).
   if (!blocks()->is_empty()) {
     v->VisitPointers(blocks()->last(), handle_scope_data_.next);
@@ -6405,12 +6389,6 @@ void HandleScopeImplementer::IterateThis(ObjectVisitor* v) {
     Object** start = reinterpret_cast<Object**>(&saved_contexts_.first());
     v->VisitPointers(start, start + saved_contexts_.length());
   }
-
-  for (DeferredHandles* deferred = deferred_handles_head_;
-       deferred != NULL;
-       deferred = deferred->next_) {
-    deferred->Iterate(v);
-  }
 }
 
 
@@ -6429,75 +6407,4 @@ char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   return storage + ArchiveSpacePerThread();
 }
 
-
-DeferredHandles* HandleScopeImplementer::Detach(Object** prev_limit) {
-  DeferredHandles* deferred = new DeferredHandles(
-      deferred_handles_head_, isolate()->handle_scope_data()->next, this);
-
-  while (!blocks_.is_empty()) {
-    Object** block_start = blocks_.last();
-    Object** block_limit = &block_start[kHandleBlockSize];
-    // We should not need to check for NoHandleAllocation here. Assert
-    // this.
-    ASSERT(prev_limit == block_limit ||
-           !(block_start <= prev_limit && prev_limit <= block_limit));
-    if (prev_limit == block_limit) break;
-    deferred->blocks_.Add(blocks_.last());
-    blocks_.RemoveLast();
-  }
-
-  ASSERT(!blocks_.is_empty() && prev_limit != NULL);
-  deferred_handles_head_ = deferred;
-  ASSERT(last_handle_before_deferred_block_ != NULL);
-  last_handle_before_deferred_block_ = NULL;
-  return deferred;
-}
-
-
-void HandleScopeImplementer::DestroyDeferredHandles(DeferredHandles* deferred) {
-  if (deferred_handles_head_ == deferred) {
-    deferred_handles_head_ = deferred_handles_head_->next_;
-  }
-  if (deferred->next_ != NULL) {
-    deferred->next_->previous_ = deferred->previous_;
-  }
-  if (deferred->previous_ != NULL) {
-    deferred->previous_->next_ = deferred->next_;
-  }
-  for (int i = 0; i < deferred->blocks_.length(); i++) {
-#ifdef DEBUG
-    HandleScope::ZapRange(deferred->blocks_[i],
-                          &deferred->blocks_[i][kHandleBlockSize]);
-#endif
-    if (spare_ != NULL) DeleteArray(spare_);
-    spare_ = deferred->blocks_[i];
-  }
-}
-
-
-void HandleScopeImplementer::BeginDeferredScope() {
-  ASSERT(last_handle_before_deferred_block_ == NULL);
-  last_handle_before_deferred_block_ = isolate()->handle_scope_data()->next;
-}
-
-
-DeferredHandles::~DeferredHandles() {
-  impl_->DestroyDeferredHandles(this);
-}
-
-
-void DeferredHandles::Iterate(ObjectVisitor* v) {
-  ASSERT(!blocks_.is_empty());
-
-  for (int i = 0; i < (blocks_.length() - 1); i++) {
-    v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
-  }
-
-  ASSERT((last_block_limit_ >= blocks_.last()) &&
-         (last_block_limit_ < &(blocks_.last())[kHandleBlockSize]));
-
-  v->VisitPointers(blocks_.last(), last_block_limit_);
-}
-
-
 } }  // namespace v8::internal
diff --git a/src/api.h b/src/api.h
index cd6c3da078..58e6a6e410 100644
--- a/src/api.h
+++ b/src/api.h
@@ -392,28 +392,6 @@ class StringTracker {
 };
 
 
-class DeferredHandles {
- public:
-  ~DeferredHandles();
-
- private:
-  DeferredHandles(DeferredHandles* next, Object** last_block_limit,
-                  HandleScopeImplementer* impl)
-      : next_(next), previous_(NULL), last_block_limit_(last_block_limit),
-        impl_(impl) {}
-
-  void Iterate(ObjectVisitor* v);
-
-  List<Object**> blocks_;
-  DeferredHandles* next_;
-  DeferredHandles* previous_;
-  Object** last_block_limit_;
-  HandleScopeImplementer* impl_;
-
-  friend class HandleScopeImplementer;
-};
-
-
 // This class is here in order to be able to declare it a friend of
 // HandleScope.  Moving these methods to be members of HandleScope would be
 // neat in some ways, but it would expose internal implementation details in
@@ -431,9 +409,7 @@ class HandleScopeImplementer {
         entered_contexts_(0),
         saved_contexts_(0),
         spare_(NULL),
-        call_depth_(0),
-        last_handle_before_deferred_block_(NULL),
-        deferred_handles_head_(NULL) { }
+        call_depth_(0) { }
 
   ~HandleScopeImplementer() {
     DeleteArray(spare_);
@@ -469,7 +445,6 @@ class HandleScopeImplementer {
   inline bool HasSavedContexts();
 
   inline List<internal::Object**>* blocks() { return &blocks_; }
-  Isolate* isolate() const { return isolate_; }
 
  private:
   void ResetAfterArchive() {
@@ -494,10 +469,6 @@ class HandleScopeImplementer {
     ASSERT(call_depth_ == 0);
   }
 
-  void BeginDeferredScope();
-  DeferredHandles* Detach(Object** prev_limit);
-  void DestroyDeferredHandles(DeferredHandles* handles);
-
   Isolate* isolate_;
   List<internal::Object**> blocks_;
   // Used as a stack to keep track of entered contexts.
@@ -506,8 +477,6 @@ class HandleScopeImplementer {
   List<Context*> saved_contexts_;
   Object** spare_;
   int call_depth_;
-  Object** last_handle_before_deferred_block_;
-  DeferredHandles* deferred_handles_head_;
   // This is only used for threading support.
   v8::ImplementationUtilities::HandleScopeData handle_scope_data_;
 
@@ -515,9 +484,6 @@ class HandleScopeImplementer {
   char* RestoreThreadHelper(char* from);
   char* ArchiveThreadHelper(char* to);
 
-  friend class DeferredHandles;
-  friend class DeferredHandleScope;
-
   DISALLOW_COPY_AND_ASSIGN(HandleScopeImplementer);
 };
 
diff --git a/src/compiler.cc b/src/compiler.cc
index 06a056a917..d35532f045 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -61,8 +61,7 @@ CompilationInfo::CompilationInfo(Handle<Script> script, Zone* zone)
       extension_(NULL),
       pre_parse_data_(NULL),
       osr_ast_id_(AstNode::kNoNumber),
-      zone_(zone),
-      deferred_handles_(NULL) {
+      zone_(zone) {
   Initialize(BASE);
 }
 
@@ -80,8 +79,7 @@ CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info,
       extension_(NULL),
       pre_parse_data_(NULL),
       osr_ast_id_(AstNode::kNoNumber),
-      zone_(zone),
-      deferred_handles_(NULL) {
+      zone_(zone) {
   Initialize(BASE);
 }
 
@@ -99,17 +97,11 @@ CompilationInfo::CompilationInfo(Handle<JSFunction> closure, Zone* zone)
       extension_(NULL),
       pre_parse_data_(NULL),
       osr_ast_id_(AstNode::kNoNumber),
-      zone_(zone),
-      deferred_handles_(NULL) {
+      zone_(zone) {
   Initialize(BASE);
 }
 
 
-CompilationInfo::~CompilationInfo() {
-  delete deferred_handles_;
-}
-
-
 // Disable optimization for the rest of the compilation pipeline.
 void CompilationInfo::DisableOptimization() {
   bool is_optimizable_closure =
diff --git a/src/compiler.h b/src/compiler.h
index 135904860e..26c0ac43c1 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -45,8 +45,6 @@ class CompilationInfo BASE_EMBEDDED {
   CompilationInfo(Handle<SharedFunctionInfo> shared_info, Zone* zone);
   CompilationInfo(Handle<JSFunction> closure, Zone* zone);
 
-  ~CompilationInfo();
-
   Isolate* isolate() {
     ASSERT(Isolate::Current() == isolate_);
     return isolate_;
@@ -175,11 +173,6 @@ class CompilationInfo BASE_EMBEDDED {
   // current compilation pipeline.
   void AbortOptimization();
 
-  void set_deferred_handles(DeferredHandles* deferred_handles) {
-    ASSERT(deferred_handles_ == NULL);
-    deferred_handles_ = deferred_handles;
-  }
-
  private:
   Isolate* isolate_;
 
@@ -266,8 +259,6 @@ class CompilationInfo BASE_EMBEDDED {
   // CompilationInfo allocates.
   Zone* zone_;
 
-  DeferredHandles* deferred_handles_;
-
   DISALLOW_COPY_AND_ASSIGN(CompilationInfo);
 };
 
@@ -295,23 +286,6 @@ class CompilationInfoWithZone: public CompilationInfo {
 };
 
 
-// A wrapper around a CompilationInfo that detaches the Handles from
-// the underlying DeferredHandleScope and stores them in info_ on
-// destruction.
-class CompilationHandleScope BASE_EMBEDDED {
- public:
-  explicit CompilationHandleScope(CompilationInfo* info)
-      : deferred_(info->isolate()), info_(info) {}
-  ~CompilationHandleScope() {
-    info_->set_deferred_handles(deferred_.Detach());
-  }
-
- private:
-  DeferredHandleScope deferred_;
-  CompilationInfo* info_;
-};
-
-
 // The V8 compiler
 //
 // General strategy: Source code is translated into an anonymous function w/o
diff --git a/src/handles.cc b/src/handles.cc
index 1962e2f651..def1604ac7 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -958,45 +958,4 @@ int Utf8Length(Handle<String> str) {
   return len;
 }
 
-
-DeferredHandleScope::DeferredHandleScope(Isolate* isolate)
-    : impl_(isolate->handle_scope_implementer()) {
-  impl_->BeginDeferredScope();
-  Object** new_next = impl_->GetSpareOrNewBlock();
-  Object** new_limit = &new_next[kHandleBlockSize];
-  impl_->blocks()->Add(new_next);
-
-  v8::ImplementationUtilities::HandleScopeData* data =
-      impl_->isolate()->handle_scope_data();
-#ifdef DEBUG
-  prev_level_ = data->level;
-#endif
-  data->level++;
-  prev_limit_ = data->limit;
-  prev_next_ = data->next;
-  data->next = new_next;
-  data->limit = new_limit;
-}
-
-
-DeferredHandleScope::~DeferredHandleScope() {
-  impl_->isolate()->handle_scope_data()->level--;
-  ASSERT(handles_detached_);
-  ASSERT(impl_->isolate()->handle_scope_data()->level == prev_level_);
-}
-
-
-DeferredHandles* DeferredHandleScope::Detach() {
-  DeferredHandles* deferred = impl_->Detach(prev_limit_);
-  v8::ImplementationUtilities::HandleScopeData* data =
-      impl_->isolate()->handle_scope_data();
-  data->next = prev_next_;
-  data->limit = prev_limit_;
-#ifdef DEBUG
-  handles_detached_ = true;
-#endif
-  return deferred;
-}
-
-
 } }  // namespace v8::internal
diff --git a/src/handles.h b/src/handles.h
index aca869026e..960696b5fb 100644
--- a/src/handles.h
+++ b/src/handles.h
@@ -95,9 +95,6 @@ class Handle {
 };
 
 
-class HandleScopeImplementer;
-
-
 // A stack-allocated class that governs a number of local handles.
 // After a handle scope has been created, all local handles will be
 // allocated within that handle scope until either the handle scope is
@@ -160,37 +157,10 @@ class HandleScope {
   static void ZapRange(internal::Object** start, internal::Object** end);
 
   friend class v8::HandleScope;
-  friend class v8::internal::HandleScopeImplementer;
   friend class v8::ImplementationUtilities;
 };
 
 
-class DeferredHandles;
-
-
-class DeferredHandleScope {
- public:
-  explicit DeferredHandleScope(Isolate* isolate);
-  // The DeferredHandles object returned stores the Handles created
-  // since the creation of this DeferredHandleScope.  The Handles are
-  // alive as long as the DeferredHandles object is alive.
-  DeferredHandles* Detach();
-  ~DeferredHandleScope();
-
- private:
-  Object** prev_limit_;
-  Object** prev_next_;
-  HandleScopeImplementer* impl_;
-
-#ifdef DEBUG
-  bool handles_detached_;
-  int prev_level_;
-#endif
-
-  friend class HandleScopeImplementer;
-};
-
-
 // ----------------------------------------------------------------------------
 // Handle operations.
 // They might invoke garbage collection. The result is an handle to
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index a1ec78eda4..0766760dee 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3053,7 +3053,6 @@ HGraph* HGraphBuilder::CreateGraph() {
 
   {
     HPhase phase("H_Block building");
-    CompilationHandleScope handle_scope(info());
     current_block_ = graph()->entry_block();
 
     Scope* scope = info()->scope();