libctf: look for BSD versus GNU qsort_r signatures

[deliverable/binutils-gdb.git] / libctf / configure.ac

diff --git a/libctf/configure.ac b/libctf/configure.ac
index 8fd5388d2a0b2c5b014e792f1515525a48fd9a79..beb90ba75cc4cf58329da2f5551d81201affe2db 100644 (file)
--- a/libctf/configure.ac
+++ b/libctf/configure.ac
@@ -90,8 +90,48 @@ fi
 AC_C_BIGENDIAN
 AC_CHECK_HEADERS(byteswap.h endian.h)
 AC_CHECK_FUNCS(pread)
-AC_CHECK_DECLS([qsort_r])
-AC_LIBOBJ([qsort_r])
+
+dnl Check for qsort_r.  (Taken from gnulib.)
+AC_CHECK_FUNCS_ONCE([qsort_r])
+if test $ac_cv_func_qsort_r = yes; then
+  AC_CACHE_CHECK([for qsort_r signature], [ac_cv_libctf_qsort_r_signature],
+    [AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM([[#undef qsort_r
+                          #include <stdlib.h>
+                          void qsort_r (void *, size_t, size_t,
+                                        int (*) (void const *, void const *,
+                                                 void *),
+                                        void *);
+                          void (*p) (void *, size_t, size_t,
+                                     int (*) (void const *, void const *,
+                                              void *),
+                                     void *) = qsort_r;
+                        ]])],
+       [ac_cv_libctf_qsort_r_signature=GNU],
+       [AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM([[#undef qsort_r
+                            #include <stdlib.h>
+                             void qsort_r (void *, size_t, size_t, void *,
+                                           int (*) (void *,
+                                                    void const *,
+                                                    void const *));
+                             void (*p) (void *, size_t, size_t, void *,
+                                        int (*) (void *, void const *,
+                                                 void const *)) = qsort_r;
+                           ]])],
+          [ac_cv_libctf_qsort_r_signature=BSD],
+          [ac_cv_libctf_qsort_r_signature=unknown])])])
+fi
+
+case x$ac_cv_libctf_qsort_r_signature in
+  xGNU)     AC_DEFINE([HAVE_QSORT_R_ARG_LAST], 1,
+            [Whether a qsort_r exists with a void *arg as its last arg.]);;
+  xBSD)     AC_DEFINE([HAVE_QSORT_R_COMPAR_LAST], 1,
+            [Whether a qsort_r exists with the compar function as its last arg.]);;
+  *) ac_cv_libctf_qsort_r_signature=unknown;;
+esac
+
+AM_CONDITIONAL(NEED_CTF_QSORT_R, test "${ac_cv_libctf_qsort_r_signature}" = unknown)
 
 AC_CONFIG_FILES(Makefile)
 AC_CONFIG_HEADERS(config.h)