Introduce a new OpaquePtr<N> struct type, which is a simple POD wrapper for a

pointer.  Its purpose in life is to be a glorified void*, but which does not
implicitly convert to void* or other OpaquePtr's with a different UID.

Introduce Action::DeclPtrTy which is a typedef for OpaquePtr<0>.  Change the 
entire parser/sema interface to use DeclPtrTy instead of DeclTy*.  This
makes the C++ compiler enforce that these aren't convertible to other opaque
types.

We should also convert ExprTy, StmtTy, TypeTy, AttrTy, BaseTy, etc,
but I don't plan to do that in the short term.

The one outstanding known problem with this patch is that we lose the 
bitmangling optimization where ActionResult<DeclPtrTy> doesn't know how to
bitmangle the success bit into the low bit of DeclPtrTy.  I will rectify
this with a subsequent patch.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67952 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 3 deletions

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 21254ea054..b8969a2202 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -707,7 +707,8 @@ QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip) {
         llvm::SmallVector<QualType, 16> ArgTys;
         
         for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
-          ParmVarDecl *Param = (ParmVarDecl *)FTI.ArgInfo[i].Param;
+          ParmVarDecl *Param =
+            cast<ParmVarDecl>(FTI.ArgInfo[i].Param.getAs<Decl>());
           QualType ArgTy = Param->getType();
           assert(!ArgTy.isNull() && "Couldn't parse type?");
 
@@ -849,8 +850,8 @@ QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S, unsigned Skip) {
 
 /// ObjCGetTypeForMethodDefinition - Builds the type for a method definition
 /// declarator
-QualType Sema::ObjCGetTypeForMethodDefinition(DeclTy *D) {
-  ObjCMethodDecl *MDecl = cast<ObjCMethodDecl>(static_cast<Decl *>(D));
+QualType Sema::ObjCGetTypeForMethodDefinition(DeclPtrTy D) {
+  ObjCMethodDecl *MDecl = cast<ObjCMethodDecl>(D.getAs<Decl>());
   QualType T = MDecl->getResultType();
   llvm::SmallVector<QualType, 16> ArgTys;