Fix memory leak in assert scopes.

src/assert-scope.h

Index: src/assert-scope.h
diff --git a/src/assert-scope.h b/src/assert-scope.h
index e2ec542a7708230af2bee1fc4f4840218afd967e..6f264a04c3af9bc8873bdd5fb7441297e329faa4 100644
--- a/src/assert-scope.h
+++ b/src/assert-scope.h
@@ -78,8 +78,10 @@ class PerThreadAssertScopeBase {
 #ifdef DEBUG
 
  protected:
+  enum AcquireAssertDataMode { CREATE_IF_ABSENT, NULL_IF_ABSENT };

[Sven Panne, 2013/06/12 06:57:37]

This is getting a little bit confusing... I think that instead of introducing
this enum, we should actually just split AssertData() into 2 methods: One for
retrieving PerThreadAssertData from TLS and one putting it into TLS. IsAllowed
simply uses the first method, while the PerThreadAssertScopeBase constructor
uses a combination of the 2 methods.

http://www.refactoring.com/catalog/replaceParameterWithExplicitMethods.html

+
   PerThreadAssertScopeBase() {
-    data_ = AssertData();
+    data_ = AssertData(CREATE_IF_ABSENT);
     data_->increment_level();
   }
 
@@ -92,10 +94,10 @@ class PerThreadAssertScopeBase {
     Thread::SetThreadLocal(thread_local_key, NULL);
   }
 
-  static PerThreadAssertData* AssertData() {
+  static PerThreadAssertData* AssertData(AcquireAssertDataMode mode) {
     PerThreadAssertData* data = reinterpret_cast<PerThreadAssertData*>(
             Thread::GetThreadLocal(thread_local_key));
-    if (data == NULL) {
+    if (data == NULL && mode == CREATE_IF_ABSENT) {
       data = new PerThreadAssertData();
       Thread::SetThreadLocal(thread_local_key, data);
     }
@@ -124,7 +126,10 @@ class PerThreadAssertScope : public PerThreadAssertScopeBase {
 
   ~PerThreadAssertScope() { data_->set(type, old_state_); }
 
-  static bool IsAllowed() { return AssertData()->get(type); }
+  static bool IsAllowed() {
+    PerThreadAssertData* data = AssertData(NULL_IF_ABSENT);
+    return data == NULL || data->get(type);
+  }
 
  private:
   bool old_state_;