1 # 2 # Determine if the printf() functions have the %a format character. 3 # This is modified from: 4 # http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_slist.html 5 AC_DEFUN([AC_C_PRINTF_A], 6 [AC_CACHE_CHECK([if printf has the %a format character],[llvm_cv_c_printf_a], 7 [AC_LANG_PUSH([C]) 8 AC_RUN_IFELSE([ 9 AC_LANG_PROGRAM([[ 10 #include <stdio.h> 11 #include <stdlib.h> 12 ]],[[ 13 volatile double A, B; 14 char Buffer[100]; 15 A = 1; 16 A /= 10.0; 17 sprintf(Buffer, "%a", A); 18 B = atof(Buffer); 19 if (A != B) 20 return (1); 21 if (A != 0x1.999999999999ap-4) 22 return (1); 23 return (0);]])], 24 llvm_cv_c_printf_a=yes, 25 llvmac_cv_c_printf_a=no, 26 llvmac_cv_c_printf_a=no) 27 AC_LANG_POP([C])]) 28 if test "$llvm_cv_c_printf_a" = "yes"; then 29 AC_DEFINE([HAVE_PRINTF_A],[1],[Define to have the %a format string]) 30 fi 31 ]) 32
