[PATCH] configure: Add needed system headers in checks

[Khem Raj]

Newer compilers throw warnings when a funciton is used with implicit
declaration and enabling -Werror can silently fail these tests and
result in wrong configure results. Therefore add the needed headers in
the AC_TRY_LINK macros

        * configure.ac: Add missing system headers in AC_TRY_LINK.
---
 configure.ac | 57 +++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 43 insertions(+), 14 deletions(-)

diff --git a/configure.ac b/configure.ac
index c0f02df..d308079 100644
--- a/configure.ac
+++ b/configure.ac
@@ -233,6 +233,7 @@ AC_CHECKING(BSD job jontrol)
 AC_TRY_LINK(
 [#include <sys/types.h>
 #include <sys/ioctl.h>
+#include <unistd.h>
 ], [
 #ifdef POSIX
 tcsetpgrp(0, 0);
@@ -250,12 +251,16 @@ dnl
 dnl    ****  setresuid(), setreuid(), seteuid()  ****
 dnl
 AC_CHECKING(setresuid)
-AC_TRY_LINK(,[
-setresuid(0, 0, 0);
+AC_TRY_LINK([
+#include <unistd.h>
+],[
+return setresuid(0, 0, 0);
 ], AC_DEFINE(HAVE_SETRESUID))
 AC_CHECKING(setreuid)
-AC_TRY_LINK(,[
-setreuid(0, 0);
+AC_TRY_LINK([
+#include <unistd.h>
+],[
+return setreuid(0, 0);
 ], AC_DEFINE(HAVE_SETREUID))
 dnl
 dnl seteuid() check:
@@ -274,7 +279,9 @@ seteuid(0);
 
 dnl execvpe
 AC_CHECKING(execvpe)
-AC_TRY_LINK(,[
+AC_TRY_LINK([
+    #include <unistd.h>
+],[
     execvpe(0, 0, 0);
 ], AC_DEFINE(HAVE_EXECVPE)
 CFLAGS="$CFLAGS -D_GNU_SOURCE")
@@ -284,10 +291,18 @@ dnl    ****  select()  ****
 dnl
 
 AC_CHECKING(select)
-AC_TRY_LINK(,[select(0, 0, 0, 0, 0);],, 
+AC_TRY_LINK([
+    #include <sys/select.h>
+],[
+    select(0, 0, 0, 0, 0);
+],, 
 LIBS="$LIBS -lnet -lnsl"
 AC_CHECKING(select with $LIBS)
-AC_TRY_LINK(,[select(0, 0, 0, 0, 0);],, 
+AC_TRY_LINK([
+    #include <sys/select.h>
+],[
+    select(0, 0, 0, 0, 0);
+],, 
 AC_MSG_ERROR(!!! no select - no screen))
 )
 dnl
@@ -624,11 +639,19 @@ dnl
 dnl    ****  termcap or terminfo  ****
 dnl
 AC_CHECKING(for tgetent)
-AC_TRY_LINK(,tgetent((char *)0, (char *)0);,,
+AC_TRY_LINK([
+    #include <curses.h>
+    #include <term.h>
+],[
+    tgetent((char *)0, (char *)0);
+],,
 olibs="$LIBS"
 LIBS="-lcurses $olibs"
 AC_CHECKING(libcurses)
-AC_TRY_LINK(,[
+AC_TRY_LINK([
+    #include <curses.h>
+    #include <term.h>
+],[
 #ifdef __hpux
 __sorry_hpux_libcurses_is_totally_broken_in_10_10();
 #else
@@ -871,7 +894,7 @@ test -f /usr/lib/libutil.a && LIBS="$LIBS -lutil"
 fi
 
 AC_CHECKING(getloadavg)
-AC_TRY_LINK(,[getloadavg((double *)0, 0);],
+AC_TRY_LINK([#include <stdlib.h>],[getloadavg((double *)0, 0);],
 AC_DEFINE(LOADAV_GETLOADAVG) load=1,
 if test "$cross_compiling" = no && test -f /usr/lib/libkvm.a ; then
 olibs="$LIBS"
@@ -1109,10 +1132,10 @@ AC_CHECKING(IRIX sun library)
 AC_TRY_LINK(,,,LIBS="$oldlibs")
 
 AC_CHECKING(syslog)
-AC_TRY_LINK(,[closelog();], , [oldlibs="$LIBS"
+AC_TRY_LINK([#include <syslog.h>],[closelog();], , [oldlibs="$LIBS"
 LIBS="$LIBS -lbsd"
 AC_CHECKING(syslog in libbsd.a)
-AC_TRY_LINK(, [closelog();], AC_NOTE(- found.), [LIBS="$oldlibs"
+AC_TRY_LINK([#include <syslog.h>], [closelog();], AC_NOTE(- found.), 
[LIBS="$oldlibs"
 AC_NOTE(- bad news: syslog missing.) AC_DEFINE(NOSYSLOG)])])
 
 AC_EGREP_CPP(YES_IS_DEFINED,
@@ -1149,7 +1172,7 @@ AC_CHECKING(getspnam)
 AC_TRY_LINK([#include <shadow.h>], [getspnam("x");],AC_DEFINE(SHADOWPW))
 
 AC_CHECKING(getttyent)
-AC_TRY_LINK(,[getttyent();], AC_DEFINE(GETTTYENT))
+AC_TRY_LINK([#include <ttyent.h>],[getttyent();], AC_DEFINE(GETTTYENT))
 
 AC_CHECKING(fdwalk)
 AC_TRY_LINK([#include <stdlib.h>], [fdwalk(NULL, 
NULL);],AC_DEFINE(HAVE_FDWALK))
@@ -1204,7 +1227,13 @@ main() {
 AC_SYS_LONG_FILE_NAMES
 
 AC_MSG_CHECKING(for vsprintf)
-AC_TRY_LINK([#include <stdarg.h>],[va_list valist; vsprintf(0,0,valist);], 
AC_MSG_RESULT(yes);AC_DEFINE(USEVARARGS), AC_MSG_RESULT(no))
+AC_TRY_LINK([
+    #include <stdarg.h>
+    #include <stdio.h>
+],[
+   va_list valist;
+   vsprintf(0,0,valist);
+], AC_MSG_RESULT(yes);AC_DEFINE(USEVARARGS), AC_MSG_RESULT(no))
 
 AC_HEADER_DIRENT
 
-- 
2.37.2