[OpenCL] Disallow taking an address of a function.

An undecorated function designator implies taking the address of a function,
which is illegal in OpenCL. Implementing a check for this earlier to allow
the error to be reported even in the presence of other more obvious errors.

Patch by Neil Hickey!

http://reviews.llvm.org/D15691

llvm-svn: 256838

1 files changed, 16 insertions, 1 deletions

diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 490bd5ada62..1fd98c140e0 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -1334,8 +1334,23 @@ ExprResult Parser::ParseCastExpression(bool isUnaryExpression,
     return ExprError();
   }
 
+  // Check to see whether Res is a function designator only. If it is and we
+  // are compiling for OpenCL, we need to return an error as this implies
+  // that the address of the function is being taken, which is illegal in CL.
+
   // These can be followed by postfix-expr pieces.
-  return ParsePostfixExpressionSuffix(Res);
+  Res = ParsePostfixExpressionSuffix(Res);
+  if (getLangOpts().OpenCL)
+    if (Expr *PostfixExpr = Res.get()) {
+      QualType Ty = PostfixExpr->getType();
+      if (!Ty.isNull() && Ty->isFunctionType()) {
+        Diag(PostfixExpr->getExprLoc(),
+             diag::err_opencl_taking_function_address_parser);
+        return ExprError();
+      }
+    }
+
+  return Res;
 }
 
 /// \brief Once the leading part of a postfix-expression is parsed, this