1 files changed, 106 insertions, 0 deletions
diff --git a/m4/macros/check_extern.m4 b/m4/macros/check_extern.m4
new file mode 100644
index 000000000000..b28dc9e903c8
--- /dev/null
+++ b/m4/macros/check_extern.m4
@@ -0,0 +1,106 @@
+dnl ######################################################################
+dnl check for external definition for a function (not external variables)
+dnl Usage AMU_CHECK_EXTERN(extern)
+dnl Checks for external definition for "extern" that is delimited on the
+dnl left and the right by a character that is not a valid symbol character.
+dnl
+dnl Note that $pattern below is very carefully crafted to match any system
+dnl external definition, with __P posix prototypes, with or without an extern
+dnl word, etc.  Think twice before changing this.
+AC_DEFUN([AMU_CHECK_EXTERN],
+[
+# store variable name for external definition
+ac_upcase_extern_name=`echo $1 | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
+ac_safe=HAVE_EXTERN_$ac_upcase_extern_name
+# check for cached value and set it if needed
+AMU_CACHE_CHECK_DYNAMIC(external function definition for $1,
+ac_cv_extern_$1,
+[
+# the old pattern assumed that the complete external definition is on one
+# line but on some systems it is split over several lines, so only match
+# beginning of the extern definition including the opening parenthesis.
+#pattern="(extern)?.*[^a-zA-Z0-9_]$1[^a-zA-Z0-9_]?.*\(.*\).*;"
+pattern="(extern)?.*[[^a-zA-Z0-9_]]$1[[^a-zA-Z0-9_]]?.*\("
+AC_EGREP_CPP(${pattern},
+[
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif /* HAVE_SYS_TYPES_H */
+#ifdef HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif /* HAVE_SYS_WAIT_H */
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else /* not TIME_WITH_SYS_TIME */
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else /* not HAVE_SYS_TIME_H */
+#  include <time.h>
+# endif /* not HAVE_SYS_TIME_H */
+#endif /* not TIME_WITH_SYS_TIME */
+
+#if defined(_AIX) && defined(HAVE_SYS_VMOUNT_H)
+# include <sys/vmount.h>
+#endif /* defined(_AIX) && defined(HAVE_SYS_VMOUNT_H) */
+
+#ifdef HAVE_STDIO_H
+# include <stdio.h>
+#endif /* HAVE_STDIO_H */
+#ifdef HAVE_STDLIB_H
+# include <stdlib.h>
+#endif /* HAVE_STDLIB_H */
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+#if HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#ifdef HAVE_NETDB_H
+# include <netdb.h>
+#endif /* HAVE_NETDB_H */
+#ifdef HAVE_CLUSTER_H
+# include <cluster.h>
+#endif /* HAVE_CLUSTER_H */
+#ifdef HAVE_RPC_RPC_H
+/*
+ * Turn on PORTMAP, so that additional header files would get included
+ * and the important definition for UDPMSGSIZE is included too.
+ */
+# ifndef PORTMAP
+#  define PORTMAP
+# endif /* not PORTMAP */
+# include <rpc/rpc.h>
+# ifndef XDRPROC_T_TYPE
+typedef bool_t (*xdrproc_t) __P ((XDR *, __ptr_t, ...));
+# endif /* not XDRPROC_T_TYPE */
+#endif /* HAVE_RPC_RPC_H */
+
+#if defined(HAVE_TCPD_H) && defined(HAVE_LIBWRAP)
+# include <tcpd.h>
+#endif /* defined(HAVE_TCPD_H) && defined(HAVE_LIBWRAP) */
+
+], eval "ac_cv_extern_$1=yes", eval "ac_cv_extern_$1=no")
+])
+# check if need to define variable
+if test "`eval echo '$''{ac_cv_extern_'$1'}'`" = yes
+then
+  AC_DEFINE_UNQUOTED($ac_safe)
+fi
+])
+dnl ======================================================================
+
+dnl ######################################################################
+dnl run AMU_CHECK_EXTERN on each argument given
+dnl Usage: AMU_CHECK_EXTERNS(arg arg arg ...)
+AC_DEFUN([AMU_CHECK_EXTERNS],
+[
+for ac_tmp_arg in $1
+do
+AMU_CHECK_EXTERN($ac_tmp_arg)
+done
+])
+dnl ======================================================================