Fix PR3766, a really nasty silent miscompilation case where we emitted

a warning and then threw away the AST.  While I'm in there, tighten up the
code to actually reject completely bogus cases (sending a message to a 
struct).  We still allow sending a message to an int, which doesn't make
sense but GCC allows it and is easy to support.

llvm-svn: 66468

1 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index 512a72f9b47..98fbd963311 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -489,7 +489,7 @@ Sema::ExprResult Sema::ActOnInstanceMessage(ExprTy *receiver, Selector Sel,
 
   // Handle messages to id.
   if (ReceiverCType == Context.getCanonicalType(Context.getObjCIdType()) ||
-      ReceiverCType->getAsBlockPointerType()) {
+      ReceiverCType->isBlockPointerType()) {
     ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(
                                Sel, SourceRange(lbrac,rbrac));
     if (!Method)
@@ -582,9 +582,18 @@ Sema::ExprResult Sema::ActOnInstanceMessage(ExprTy *receiver, Selector Sel,
     }
     if (Method && DiagnoseUseOfDecl(Method, receiverLoc))
       return true;
-  } else {
+  } else if (!Context.getObjCIdType().isNull() &&
+             (ReceiverCType->isPointerType() ||
+              (ReceiverCType->isIntegerType() && 
+               ReceiverCType->isScalarType()))) {
+    // Implicitly convert integers and pointers to 'id' but emit a warning.
     Diag(lbrac, diag::warn_bad_receiver_type)
       << RExpr->getType() << RExpr->getSourceRange();
+    ImpCastExprToType(RExpr, Context.getObjCIdType());
+  } else {
+    // Reject other random receiver types (e.g. structs).
+    Diag(lbrac, diag::err_bad_receiver_type)
+      << RExpr->getType() << RExpr->getSourceRange();
     return true;
   }