llvm-6502/projects/sample/autoconf/m4/c_printf_a.m4
Daniel Dunbar 2532fa21a9 projects/sample: Import adapted form of current LLVM autoconf/Makefile setup so that projects/sample is standalone and not tied to the LLVM build setup.
- This currently just moves over all of the behavior from LLVM. Eventually all of the configure checks that are directly needed by the LLVM build setup should probably go away, and the project should manage their own configuration checks if necessary.

 - This is the 1st half of this work, the actual Makefile.common hasn't moved over yet. I've tried to stage this in such a way that incremental builds will properly reconfigure for most active developers (the Makefiles don't handle reconfiguring in a perfectly reliable way, and I haven't found an easy way to make them do so).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142456 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-18 23:10:47 +00:00

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#
# Determine if the printf() functions have the %a format character.
# This is modified from:
# http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_slist.html
AC_DEFUN([AC_C_PRINTF_A],
[AC_CACHE_CHECK([if printf has the %a format character],[llvm_cv_c_printf_a],
[AC_LANG_PUSH([C])
AC_RUN_IFELSE([
AC_LANG_PROGRAM([[
#include <stdio.h>
#include <stdlib.h>
]],[[
volatile double A, B;
char Buffer[100];
A = 1;
A /= 10.0;
sprintf(Buffer, "%a", A);
B = atof(Buffer);
if (A != B)
return (1);
if (A != 0x1.999999999999ap-4)
return (1);
return (0);]])],
llvm_cv_c_printf_a=yes,
llvmac_cv_c_printf_a=no,
llvmac_cv_c_printf_a=no)
AC_LANG_POP([C])])
if test "$llvm_cv_c_printf_a" = "yes"; then
AC_DEFINE([HAVE_PRINTF_A],[1],[Define to have the %a format string])
fi
])