Change CodeGenModule GlobalDeclMap to directly reference globals

instead of mapping the decl to a bitcast of the global to the correct
type.
 
 - GetAddrOf{Function,GlobalVar} introduce the bitcast on every use now.

 - This solves a problem where a dangling pointer could be introduced
   by the RAUW done when replacing a forward or tentative
   definition. See testcase for more details.

 - Fixes <rdar://problem/6108358>

llvm-svn: 54211

1 files changed, 7 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 57363cddee0..3a39eb3f79d 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -66,7 +66,12 @@ class CodeGenModule {
   llvm::Function *MemCpyFn;
   llvm::Function *MemMoveFn;
   llvm::Function *MemSetFn;
-  llvm::DenseMap<const Decl*, llvm::Constant*> GlobalDeclMap;
+
+  /// GlobalDeclMap - Mapping of decls to global variables we have
+  /// already emitted. Note that the entries in this map are the
+  /// actual global and therefore may not be of the same type as the
+  /// decl, they should be bitcasted on retrieval.
+  llvm::DenseMap<const Decl*, llvm::GlobalValue*> GlobalDeclMap;
 
   /// List of static global for which code generation is delayed. When
   /// the translation unit has been fully processed we will lazily
@@ -155,7 +160,7 @@ private:
   /// ReplaceMapValuesWith - This is a really slow and bad function that
   /// searches for any entries in GlobalDeclMap that point to OldVal, changing
   /// them to point to NewVal.  This is badbadbad, FIXME!
-  void ReplaceMapValuesWith(llvm::Constant *OldVal, llvm::Constant *NewVal);
+  void ReplaceMapValuesWith(llvm::GlobalValue *OldVal, llvm::GlobalValue *NewVal);
 
   void SetFunctionAttributes(const FunctionDecl *FD,
                              llvm::Function *F,