1 files changed, 49 insertions, 13 deletions

diff --git a/lib/CodeGen/CodeGenTypes.cpp b/lib/CodeGen/CodeGenTypes.cpp
index 9375410477..ed44aec492 100644
--- a/lib/CodeGen/CodeGenTypes.cpp
+++ b/lib/CodeGen/CodeGenTypes.cpp
@@ -93,19 +93,55 @@ llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T){
 
 }
 
-// Code to verify a given function type is complete, i.e. the return type
-// and all of the argument types are complete.
-const TagType *CodeGenTypes::VerifyFuncTypeComplete(const Type* T) {
-  const FunctionType *FT = cast<FunctionType>(T);
-  if (const TagType* TT = FT->getResultType()->getAs<TagType>())
-    if (!TT->getDecl()->isDefinition())
-      return TT;
-  if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(T))
+/// isFuncTypeArgumentConvertible - Return true if the specified type in a 
+/// function argument or result position can be converted to an IR type at this
+/// point.  This boils down to being whether it is complete, as well as whether
+/// we've temporarily deferred expanding the type because we're in a recursive
+/// context.
+bool CodeGenTypes::isFuncTypeArgumentConvertible(QualType Ty){
+  // If this isn't a tagged type, we can convert it!
+  const TagType *TT = Ty->getAs<TagType>();
+  if (TT == 0) return true;
+  
+  // If it's a tagged type, but is a forward decl, we can't convert it.
+  if (!TT->getDecl()->isDefinition())
+    return false;
+  
+  // If we're not under a pointer under a struct, then we can convert it if
+  // needed.
+  if (RecursionState != RS_StructPointer)
+    return true;
+
+  // If this is an enum, then it is safe to convert.
+  const RecordType *RT = dyn_cast<RecordType>(TT);
+  if (RT == 0) return true;
+
+  // Otherwise, we have to be careful.  If it is a struct that we're in the
+  // process of expanding, then we can't convert the function type.  That's ok
+  // though because we must be in a pointer context under the struct, so we can
+  // just convert it to a dummy type.
+  //
+  // We decide this by checking whether ConvertRecordDeclType returns us an
+  // opaque type for a struct that we know is defined.
+  return !ConvertRecordDeclType(RT->getDecl())->isOpaque();
+}
+
+
+/// Code to verify a given function type is complete, i.e. the return type
+/// and all of the argument types are complete.  Also check to see if we are in
+/// a RS_StructPointer context, and if so whether any struct types have been
+/// pended.  If so, we don't want to ask the ABI lowering code to handle a type
+/// that cannot be converted to an IR type.
+bool CodeGenTypes::isFuncTypeConvertible(const FunctionType *FT) {
+  if (!isFuncTypeArgumentConvertible(FT->getResultType()))
+    return false;
+  
+  if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT))
     for (unsigned i = 0, e = FPT->getNumArgs(); i != e; i++)
-      if (const TagType *TT = FPT->getArgType(i)->getAs<TagType>())
-        if (!TT->getDecl()->isDefinition())
-          return TT;
-  return 0;
+      if (!isFuncTypeArgumentConvertible(FPT->getArgType(i)))
+        return false;
+
+  return true;
 }
 
 /// UpdateCompletedType - When we find the full definition for a TagDecl,
@@ -296,7 +332,7 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) {
     // First, check whether we can build the full function type.  If the
     // function type depends on an incomplete type (e.g. a struct or enum), we
     // cannot lower the function type.
-    if (VerifyFuncTypeComplete(Ty)) {
+    if (!isFuncTypeConvertible(cast<FunctionType>(Ty))) {
       // This function's type depends on an incomplete tag type.
       // Return a placeholder type.
       ResultType = llvm::StructType::get(getLLVMContext());