From: Chris Lattner <sabre@nondot.org>
Date: Sun, 5 Apr 2009 00:52:59 +0000 (+0000)
Subject: GCC compatibility: gcc allows applying va_args to const
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f502691c86299ed23b7e121e27610ba5bb44a1ee;p=clang

GCC compatibility: gcc allows applying va_args to const
va_lists for some reason.  This fixes rdar://6726818


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68434 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 55eaaa4bc8..a43c2c370e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -4724,7 +4724,10 @@ Sema::OwningExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc,
   Expr *E = static_cast<Expr*>(expr.get());
   UsualUnaryConversions(E);
 
-  if (CheckAssignmentConstraints(VaListType, E->getType()) != Compatible)
+  AssignConvertType ConvResult = 
+    CheckAssignmentConstraints(VaListType, E->getType());
+  if (ConvResult != Compatible &&
+      ConvResult != CompatiblePointerDiscardsQualifiers)
     return ExprError(Diag(E->getLocStart(),
                          diag::err_first_argument_to_va_arg_not_of_type_va_list)
       << E->getType() << E->getSourceRange());
diff --git a/test/Sema/varargs.c b/test/Sema/varargs.c
index 434e4ce291..7255f9fc06 100644
--- a/test/Sema/varargs.c
+++ b/test/Sema/varargs.c
@@ -60,3 +60,10 @@ void f7(int a, ...) {
   int *x = &__builtin_va_arg(ap, int); // expected-error {{address expression must be an lvalue or a function designator}}
   __builtin_va_end(ap);
 }
+
+// rdar://6726818
+void f8() {
+  const __builtin_va_list args2;
+  (void)__builtin_va_arg(args2, int);
+}
+