Introduce cleanup scopes for "if" statements in two places:

  - Outside the "if", to ensure that we destroy the condition variable
    at the end of the "if" statement rather than at the end of the
    block containing the "if" statement.
  - Inside the "then" and "else" branches, so that we emit then- or
    else-local cleanups at the end of the corresponding block when the
    block is not a compound statement.

To make adding these new cleanup scopes easier (and since
switch/do/while will all need the same treatment), added the
CleanupScope RAII object to introduce a new cleanup scope and make
sure it gets cleaned up.

llvm-svn: 89773

1 files changed, 25 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index dd26428f819..be1a15ed665 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -165,6 +165,31 @@ public:
     }
   };
 
+  /// \brief Enters a new scope for capturing cleanups, all of which will be
+  /// executed once the scope is exited.
+  class CleanupScope {
+    CodeGenFunction& CGF;
+    size_t CleanupStackDepth;
+    bool OldDidCallStackSave;
+
+    CleanupScope(const CleanupScope &); // DO NOT IMPLEMENT
+    CleanupScope &operator=(const CleanupScope &); // DO NOT IMPLEMENT
+
+  public:
+    /// \brief Enter a new cleanup scope.
+    explicit CleanupScope(CodeGenFunction &CGF) : CGF(CGF) {
+      CleanupStackDepth = CGF.CleanupEntries.size();
+      OldDidCallStackSave = CGF.DidCallStackSave;
+    }
+
+    /// \brief Exit this cleanup scope, emitting any accumulated
+    /// cleanups.
+    ~CleanupScope() {
+      CGF.DidCallStackSave = OldDidCallStackSave;
+      CGF.EmitCleanupBlocks(CleanupStackDepth);
+    }
+  };
+
   /// EmitCleanupBlocks - Takes the old cleanup stack size and emits the cleanup
   /// blocks that have been added.
   void EmitCleanupBlocks(size_t OldCleanupStackSize);