From 7a92e1ad3d44d2e0528d6cd5c1e99fc34a8acf2b Mon Sep 17 00:00:00 2001
From: Nico Weber <nicolasweber@gmx.de>
Date: Sun, 18 Jan 2015 01:50:35 +0000
Subject: [PATCH] Address review feedback from r215780: Use a flag insteda of
 the heap. No behavior change.

llvm-svn: 226389
---
 clang/include/clang/Sema/Sema.h               |  8 ++++-
 .../lib/Sema/SemaTemplateInstantiateDecl.cpp  | 36 +++++++------------
 2 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 74efa60c9366..9aed52a22dd9 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -6720,12 +6720,17 @@ public:
 
   class SavePendingInstantiationsAndVTableUsesRAII {
   public:
-    SavePendingInstantiationsAndVTableUsesRAII(Sema &S): S(S) {
+    SavePendingInstantiationsAndVTableUsesRAII(Sema &S, bool Enabled)
+        : S(S), Enabled(Enabled) {
+      if (!Enabled) return;
+
       SavedPendingInstantiations.swap(S.PendingInstantiations);
       SavedVTableUses.swap(S.VTableUses);
     }
 
     ~SavePendingInstantiationsAndVTableUsesRAII() {
+      if (!Enabled) return;
+
       // Restore the set of pending vtables.
       assert(S.VTableUses.empty() &&
              "VTableUses should be empty before it is discarded.");
@@ -6741,6 +6746,7 @@ public:
     Sema &S;
     SmallVector<VTableUse, 16> SavedVTableUses;
     std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
+    bool Enabled;
   };
 
   /// \brief The queue of implicit template instantiations that are required
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 40e86175b2cd..1df0701ee9f4 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3313,12 +3313,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
   // it marks vtables used in late parsed templates as used.
   SavePendingLocalImplicitInstantiationsRAII
       SavedPendingLocalImplicitInstantiations(*this);
-  std::unique_ptr<SavePendingInstantiationsAndVTableUsesRAII>
-      SavePendingInstantiationsAndVTableUses;
-  if (Recursive) {
-    SavePendingInstantiationsAndVTableUses.reset(
-        new SavePendingInstantiationsAndVTableUsesRAII(*this));
-  }
+  SavePendingInstantiationsAndVTableUsesRAII
+      SavePendingInstantiationsAndVTableUses(*this, /*Enabled=*/Recursive);
 
   // Call the LateTemplateParser callback if there is a need to late parse
   // a templated function definition.
@@ -3463,8 +3459,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
     // instantiation of this template.
     PerformPendingInstantiations();
 
-    // Restore PendingInstantiations and VTableUses.
-    SavePendingInstantiationsAndVTableUses.reset();
+    // PendingInstantiations and VTableUses are restored through
+    // SavePendingInstantiationsAndVTableUses's destructor.
   }
 }
 
@@ -3780,12 +3776,8 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
       // If we're performing recursive template instantiation, create our own
       // queue of pending implicit instantiations that we will instantiate
       // later, while we're still within our own instantiation context.
-      std::unique_ptr<SavePendingInstantiationsAndVTableUsesRAII>
-          SavePendingInstantiationsAndVTableUses;
-      if (Recursive) {
-        SavePendingInstantiationsAndVTableUses.reset(
-            new SavePendingInstantiationsAndVTableUsesRAII(*this));
-      }
+      SavePendingInstantiationsAndVTableUsesRAII
+          SavePendingInstantiationsAndVTableUses(*this, /*Enabled=*/Recursive);
 
       LocalInstantiationScope Local(*this);
 
@@ -3812,8 +3804,8 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
         // instantiation of this template.
         PerformPendingInstantiations();
 
-        // Restore PendingInstantiations and VTableUses.
-        SavePendingInstantiationsAndVTableUses.reset();
+        // PendingInstantiations and VTableUses are restored through
+        // SavePendingInstantiationsAndVTableUses's destructor.
       }
     }
 
@@ -3899,12 +3891,8 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
   // while we're still within our own instantiation context.
   SavePendingLocalImplicitInstantiationsRAII
       SavedPendingLocalImplicitInstantiations(*this);
-  std::unique_ptr<SavePendingInstantiationsAndVTableUsesRAII>
-      SavePendingInstantiationsAndVTableUses;
-  if (Recursive) {
-    SavePendingInstantiationsAndVTableUses.reset(
-        new SavePendingInstantiationsAndVTableUsesRAII(*this));
-  }
+  SavePendingInstantiationsAndVTableUsesRAII
+      SavePendingInstantiationsAndVTableUses(*this, /*Enabled=*/Recursive);
 
   // Enter the scope of this instantiation. We don't use
   // PushDeclContext because we don't have a scope.
@@ -3970,8 +3958,8 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
     // instantiation of this template.
     PerformPendingInstantiations();
 
-    // Restore PendingInstantiations and VTableUses.
-    SavePendingInstantiationsAndVTableUses.reset();
+    // PendingInstantiations and VTableUses are restored through
+    // SavePendingInstantiationsAndVTableUses's destructor.
   }
 }