Add DidCallStackSave variable to CodeGenFunction.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64156 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CodeGenFunction.cpp

@@ -144,6 +144,7 @@ void CodeGenFunction::StartFunction(const Decl *D, QualType RetTy,
                                     llvm::Function *Fn,
                                     const FunctionArgList &Args,
                                     SourceLocation StartLoc) {
+  DidCallStackSave = false;
   CurFuncDecl = D;
   FnRetTy = RetTy;
   CurFn = Fn;

lib/CodeGen/CodeGenFunction.h

@@ -260,6 +260,10 @@ private:
   /// which the stack depth changes.
   llvm::Value *StackDepth;
 
+  /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
+  /// calling llvm.stacksave for multiple VLAs in the same scope.
+  bool DidCallStackSave;
+  
   /// StackSaveValues - A stack(!) of stack save values. When a new scope is
   /// entered, a null is pushed on this stack. If a VLA is emitted, then the
   /// return value of llvm.stacksave() is stored at the top of this stack.