Implement C++'s restrictions on the type of an expression passed to a vararg

function: it can't be 'void' and it can't be an initializer list. We give a
hard error for these rather than treating them as undefined behavior (we can
and probably should do the same for non-POD types in C++11, but as of this
change we don't).

Slightly rework the checking of variadic arguments in a function with a format
attribute to ensure that certain kinds of format string problem (non-literal
string, too many/too few arguments, ...) don't suppress this error.

llvm-svn: 187735

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/test/CXX/expr/expr.post/expr.call/p7-0x.cpp b/clang/test/CXX/expr/expr.post/expr.call/p7-0x.cpp
index 018609d9a07..c77c47df244 100644
--- a/clang/test/CXX/expr/expr.post/expr.call/p7-0x.cpp
+++ b/clang/test/CXX/expr/expr.post/expr.call/p7-0x.cpp
@@ -20,11 +20,16 @@ struct X4 {
 
 void vararg(...);
 
+void g();
+
 void f(X1 x1, X2 x2, X3 x3, X4 x4) {
   vararg(x1); // OK
   vararg(x2); // expected-error{{cannot pass object of non-trivial type 'X2' through variadic function; call will abort at runtime}}
   vararg(x3); // OK
   vararg(x4); // expected-error{{cannot pass object of non-trivial type 'X4' through variadic function; call will abort at runtime}}
+
+  vararg(g()); // expected-error{{cannot pass expression of type 'void' to variadic function}}
+  vararg({1, 2, 3}); // expected-error{{cannot pass initializer list to variadic function}}
 }