1dnl as-compiler-flag.m4 0.1.0 2 3dnl autostars m4 macro for detection of compiler flags 4 5dnl David Schleef <ds@schleef.org> 6 7dnl $Id: as-compiler-flag.m4,v 1.1 2005/12/15 23:35:19 ds Exp $ 8 9dnl AS_COMPILER_FLAG(CFLAGS, ACTION-IF-ACCEPTED, [ACTION-IF-NOT-ACCEPTED]) 10dnl Tries to compile with the given CFLAGS. 11dnl Runs ACTION-IF-ACCEPTED if the compiler can compile with the flags, 12dnl and ACTION-IF-NOT-ACCEPTED otherwise. 13 14AC_DEFUN([AS_COMPILER_FLAG], 15[ 16 AC_MSG_CHECKING([to see if compiler understands $1]) 17 18 save_CFLAGS="$CFLAGS" 19 CFLAGS="$CFLAGS $1" 20 21 AC_TRY_COMPILE([ ], [], [flag_ok=yes], [flag_ok=no]) 22 CFLAGS="$save_CFLAGS" 23 24 if test "X$flag_ok" = Xyes ; then 25 m4_ifvaln([$2],[$2]) 26 true 27 else 28 m4_ifvaln([$3],[$3]) 29 true 30 fi 31 AC_MSG_RESULT([$flag_ok]) 32]) 33 34dnl AS_COMPILER_FLAGS(VAR, FLAGS) 35dnl Tries to compile with the given CFLAGS. 36 37AC_DEFUN([AS_COMPILER_FLAGS], 38[ 39 list=$2 40 flags_supported="" 41 flags_unsupported="" 42 AC_MSG_CHECKING([for supported compiler flags]) 43 for each in $list 44 do 45 save_CFLAGS="$CFLAGS" 46 CFLAGS="$CFLAGS $each" 47 AC_TRY_COMPILE([ ], [], [flag_ok=yes], [flag_ok=no]) 48 CFLAGS="$save_CFLAGS" 49 50 if test "X$flag_ok" = Xyes ; then 51 flags_supported="$flags_supported $each" 52 else 53 flags_unsupported="$flags_unsupported $each" 54 fi 55 done 56 AC_MSG_RESULT([$flags_supported]) 57 if test "X$flags_unsupported" != X ; then 58 AC_MSG_WARN([unsupported compiler flags: $flags_unsupported]) 59 fi 60 $1="$$1 $flags_supported" 61]) 62 63