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