Description of problem:
the function isnan is not found if the testcase is built with -std=iso9899:1990
on x86_64

Version-Release number of selected component (if applicable):

glibc-2.10.90-17

How reproducible:
just compile the following code with -std=iso9899:1990

#include <math.h>
void cmakeRequireSymbol(int dummy,...){(void)dummy;}
int main()
{
#ifndef isnan
   cmakeRequireSymbol(0,&isnan);
#endif
   return 0;
}

you will get the following errors:

In file included from /usr/include/math.h:416, from foo.c:2:
/usr/include/bits/mathinline.h: In function ‘__signbitf’:
/usr/include/bits/mathinline.h:39: error: expected ‘)’ before ‘:’ token
/usr/include/bits/mathinline.h: In function ‘__signbit’:
/usr/include/bits/mathinline.h:46: error: expected ‘)’ before ‘:’ token


Expected results:
it should compile the above code

Additional info:
It build without any problem with the current glibc/gcc in F11/F10.
I did not check whether the issue is also affacted on other arch.


i'm using the latest gcc and glibc in rawhide