vargs macro dererencing a incomplete structure

[llvmbot]

Bugzilla Link	11336
Resolution	WORKSFORME
Resolved on	Nov 08, 2011 16:44
Version	trunk
OS	All
Reporter	LLVM Bugzilla Contributor
CC	@efriedma-quic

Extended Description

The 'online-demo' compiler crash with this code:

#include <stdarg.h>

struct S;
void deref_incomplete(int a, ...)
{
va_list ap;
int i;

va_start(ap, a);
va_arg(ap, struct S);
va_end(ap);
}

clang: error: unable to execute command: Segmentation fault

[efriedma-quic]

#include <stdarg.h>

struct S;
void deref_incomplete(int a, ...)
{
va_list ap;
int i;

va_start(ap, a);
va_arg(ap, struct S);
va_end(ap);
}

[efriedma-quic]

Err, please ignore my last comment. :)

[efriedma-quic]

Trunk gives:

:10:14: error: second argument to 'va_arg' is of incomplete type 'struct S'
va_arg(ap, struct S);

/Volumes/storage/llvmbin/Release+Asserts/bin/../lib/clang/3.1/include/stdarg.h:35:50: note: expanded from macro 'va_arg'
#define va_arg(ap, type)    __builtin_va_arg(ap, type)
                                               ^
<stdin>:3:8: note: forward declaration of 'struct S'
struct S;
     ^
1 error generated.