Allow for a GCC cast extension.

Fixes part of <rdar://problem/5980829> clang on xcode: used type 'NSRange' where arithmetic or pointer type is required.

llvm-svn: 51900

1 files changed, 10 insertions, 3 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 626e829044a..c978acac63d 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -845,9 +845,16 @@ ActOnCastExpr(SourceLocation LParenLoc, TypeTy *Ty,
   // C99 6.5.4p2: the cast type needs to be void or scalar and the expression
   // type needs to be scalar.
   if (!castType->isVoidType()) {  // Cast to void allows any expr type.
-    if (!castType->isScalarType() && !castType->isVectorType())
-      return Diag(LParenLoc, diag::err_typecheck_cond_expect_scalar, 
-                  castType.getAsString(), SourceRange(LParenLoc, RParenLoc));
+    if (!castType->isScalarType() && !castType->isVectorType()) {
+      // GCC struct/union extension.
+      if (castType == castExpr->getType() &&
+          castType->isStructureType() || castType->isUnionType())
+        return Diag(LParenLoc, diag::ext_typecheck_cast_nonscalar,
+                    SourceRange(LParenLoc, RParenLoc));
+      else
+        return Diag(LParenLoc, diag::err_typecheck_cond_expect_scalar, 
+                    castType.getAsString(), SourceRange(LParenLoc, RParenLoc));
+    }
     if (!castExpr->getType()->isScalarType() && 
         !castExpr->getType()->isVectorType())
       return Diag(castExpr->getLocStart(),