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, 4 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/format-strings-0x.cpp b/clang/test/SemaCXX/format-strings-0x.cpp
index 7b3aef1ee5d..7e41c7fdbf9 100644
--- a/clang/test/SemaCXX/format-strings-0x.cpp
+++ b/clang/test/SemaCXX/format-strings-0x.cpp
@@ -24,4 +24,8 @@ void f(char **sp, float *fp) {
       \u1234\U0010fffe
       %d)foo" // expected-warning {{more '%' conversions than data arguments}}
   );
+
+  printf("init list: %d", { 0 }); // expected-error {{cannot pass initializer list to variadic function; expected type from format string was 'int'}}
+  printf("void: %d", f(sp, fp)); // expected-error {{cannot pass expression of type 'void' to variadic function; expected type from format string was 'int'}}
+  printf(0, { 0 }); // expected-error {{cannot pass initializer list to variadic function}}
 }