- AC_CHECK_DECLS([_snprintf], , , [#include <stdio.h>])
+ AC_CHECK_DECLS([_snprintf], , , [[#include <stdio.h>]])
+ dnl Knowing DBL_EXPBIT0_WORD and DBL_EXPBIT0_BIT enables an optimization
+ dnl in the code for NEED_PRINTF_LONG_DOUBLE || NEED_PRINTF_DOUBLE.
+ AC_REQUIRE([gl_DOUBLE_EXPONENT_LOCATION])
+ dnl We can avoid a lot of code by assuming that snprintf's return value
+ dnl conforms to ISO C99. So check that.
+ AC_REQUIRE([gl_SNPRINTF_RETVAL_C99])
+ case "$gl_cv_func_snprintf_retval_c99" in
+ *yes)
+ AC_DEFINE([HAVE_SNPRINTF_RETVAL_C99], [1],
+ [Define if the return value of the snprintf function is the number of
+ of bytes (excluding the terminating NUL) that would have been produced
+ if the buffer had been large enough.])
+ ;;
+ esac