Hi Bob and Chris,
On Wed, 2004-06-30 at 15:52, Bob Friesenhahn wrote:
> I was going to suggest using AC_TRY_LINK but for some reason I can't
> find it in the Autoconf documentation anymore. Instead I see a
> AC_LINK_IFELSE macro which must be used in conjunction with
> AC_LANG_PROGRAM. Maybe AC_TRY_LINK has been retired.
Yep. From what I recall the AC_*_IFELSE macros provide more
uniform/consistent interfaces than their deprecated AC_TRY_*
counterparts. Perhaps Akim can confirm this.
> Unfortunately, I do not have time to write an example. I think that
> almost any compilable code fragment which lacks a main routine will
> serve as a test. You would temporarily add the library to be tested
> to LIBS. If you have a successful link, then a main() routine was
> found somewhere.
Here's an example from the ACE configure script:
dnl Use a more comprehensive test for shm_open() since the prototype
dnl may not be visible on all platforms without enabling POSIX.1b
dnl support (e.g. when the user defines _POSIX_C_SOURCE > 2).
AC_MSG_CHECKING([for shm_open])
AC_LINK_IFELSE([AC_LANG_PROGRAM(
[[
#ifndef ACE_LACKS_SYS_TYPES_H
# include <sys/types.h>
#endif
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
]],
[[
const char name[] = "Foo";
const int oflag = O_RDONLY;
const mode_t mode = 0400; /* Whatever */
const int fd = shm_open (name, oflag, mode);
]])],
[
AC_DEFINE([ACE_HAS_SHM_OPEN])
AC_MSG_RESULT([yes])
],
[
AC_MSG_RESULT([no])
])
You'll of course have to add the library you're testing for to $LIBS
before you run the link-time test, and remove it if the test fails.
HTH,
-Ossama
--
Ossama Othman <ossama @ dre . vanderbilt . edu>
1024D/F7A394A8 - 84ED AA0B 1203 99E4 1068 70E6 5EB7 5E71 F7A3 94A8
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