AC_FUNC_ALLOCA generates warning (problem with -Werror)

[Jaap Haitsma]

Hi

AC_FUNC_ALLOCA generates the following code

#include <alloca.h>
int
main ()
{
char *p = (char *) alloca (2 * sizeof (int));
  ;
  return 0;
}

This generates a warning that the variable p is never used. This is a
problem when you run configure with CFLAG="-Werror". Compilation of the
above code will fail.

This can be easily solved by adding the following line

for (;&p!=0;) {/*Use p so we do not generate a warning */}

Jaap