It turns out that in C++ it is legal to declare functions

that return an opaque type by value, as long as you don't
call it or provide a body (you can take the address of it).
So it is wrong to insist that sret parameters not be an
opaque*.  And I guess it is really up to codegen to complain
if someone tries to call such a function.  I'm also removing
the analogous check from byval parameters, since I don't
see why we shouldn't allow them as long as no-one tries to
call the function or give it a body.

llvm-svn: 46216

1 files changed, 1 insertions, 6 deletions

diff --git a/llvm/lib/VMCore/ParameterAttributes.cpp b/llvm/lib/VMCore/ParameterAttributes.cpp
index 0cafd307b2f..b099c8fed86 100644
--- a/llvm/lib/VMCore/ParameterAttributes.cpp
+++ b/llvm/lib/VMCore/ParameterAttributes.cpp
@@ -200,14 +200,9 @@ uint16_t ParamAttr::typeIncompatible (const Type *Ty) {
     // Attributes that only apply to integers.
     Incompatible |= SExt | ZExt;
 
-  if (const PointerType *PTy = dyn_cast<PointerType>(Ty)) {
-    if (!PTy->getElementType()->isSized())
-      // The byval and sret attributes only apply to pointers to sized types.
-      Incompatible |= ByVal | StructRet;
-  } else {
+  if (!isa<PointerType>(Ty))
     // Attributes that only apply to pointers.
     Incompatible |= ByVal | Nest | NoAlias | StructRet;
-  }
 
   return Incompatible;
 }