Submitted upstream: https://github.com/proftpd/proftpd/pull/1667

From: Arjun Shankar <arjun@redhat.com>

Date: Fri, 5 May 2023 15:35:56 +0200

Subject: [PATCH] configure: Remove several implicit function declarations

During configure, some checks omit the corresponding include. A compiler

defaulting to C99 mode could cause those checks to fail since C99 does

not allow implicit function declarations. This commit fixes the same.

The configure script is re-generated.

Signed-off-by: Arjun Shankar <arjun@redhat.com>

---

 configure    | 66 +++++++++++++++++++++++++++++++++++++++----

 configure.in | 80 ++++++++++++++++++++++++++++++++++++++++++++--------

 2 files changed, 129 insertions(+), 17 deletions(-)

diff --git a/configure b/configure

index 25c8b8a6d..41f019c65 100755

--- a/configure

+++ b/configure

@@ -18305,6 +18305,20 @@ _ACEOF

 fi

+for ac_header in stddef.h crypt.h netdb.h arpa/inet.h sys/socket.h

+do :

+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`

+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"

+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :

+  cat >>confdefs.h <<_ACEOF

+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1

+_ACEOF

+

+fi

+

+done

+

+

 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for standalone crypt" >&5

 $as_echo_n "checking for standalone crypt... " >&6; }

 if ${pr_cv_lib_standalone_crypt+:} false; then :

@@ -18313,10 +18327,19 @@ else

   cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_CRYPT_H

+      # include <crypt.h>

+      #endif

+

 int

 main ()

 {

-crypt();

+

+      crypt(NULL, NULL);

+

   ;

   return 0;

 }

@@ -18388,10 +18411,19 @@ else

   cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_NETDB_H

+      # include <netdb.h>

+      #endif

+

 int

 main ()

 {

-gethostbyname();

+

+      gethostbyname(NULL);

+

   ;

   return 0;

 }

@@ -18508,10 +18540,19 @@ else

   cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_ARPA_INET_H

+      # include <arpa/inet.h>

+      #endif

+

 int

 main ()

 {

-inet_aton();

+

+      inet_aton(NULL, NULL);

+

   ;

   return 0;

 }

@@ -18584,10 +18625,16 @@ else

   cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

+      #if HAVE_NETDB_H

+      # include <netdb.h>

+      #endif

+

 int

 main ()

 {

-gethostent();

+

+      gethostent();

+

   ;

   return 0;

 }

@@ -18659,10 +18706,19 @@ else

   cat confdefs.h - <<_ACEOF >conftest.$ac_ext

 /* end confdefs.h.  */

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_SYS_SOCKET_H

+      # include <sys/socket.h>

+      #endif

+

 int

 main ()

 {

-bind();

+

+      bind(0, NULL, 0);

+

   ;

   return 0;

 }

diff --git a/configure.in b/configure.in

index 105fda3b0..f88ce1025 100644

--- a/configure.in

+++ b/configure.in

@@ -1476,18 +1476,42 @@ AC_ARG_ENABLE(transfer-buffer-size,

   ])

 dnl Checks for libraries.  Yes, this is the hard way, but it's necessary.

+AC_CHECK_HEADERS(stddef.h crypt.h netdb.h arpa/inet.h sys/socket.h)

+

 AC_CACHE_CHECK(for standalone crypt,pr_cv_lib_standalone_crypt,

-  AC_TRY_LINK(,[crypt();],

-  	pr_cv_lib_standalone_crypt="yes", pr_cv_lib_standalone_crypt="no" ))

+  AC_TRY_LINK(

+    [

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_CRYPT_H

+      # include <crypt.h>

+      #endif

+    ],

+    [

+      crypt(NULL, NULL);

+    ],

+    pr_cv_lib_standalone_crypt="yes", pr_cv_lib_standalone_crypt="no" ))

 if test "$pr_cv_lib_standalone_crypt" = "no"; then

   AC_CHECK_LIB(crypt, crypt)

 fi

 AC_CACHE_CHECK(for standalone gethostbyname,pr_cv_lib_standalone_gethost,

-  AC_TRY_LINK(,[gethostbyname();],

-  	pr_cv_lib_standalone_gethost="yes",

-	pr_cv_lib_standalone_gethost="no" ))

+  AC_TRY_LINK(

+    [

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_NETDB_H

+      # include <netdb.h>

+      #endif

+    ],

+    [

+      gethostbyname(NULL);

+    ],

+    pr_cv_lib_standalone_gethost="yes",

+    pr_cv_lib_standalone_gethost="no" ))

 if test "$pr_cv_lib_standalone_gethost" = "no"; then

   AC_CHECK_LIB(resolv, gethostbyname)

@@ -1495,25 +1519,57 @@ if test "$pr_cv_lib_standalone_gethost" = "no"; then

 fi

 AC_CACHE_CHECK(for standalone inet_aton,pr_cv_lib_standalone_aton,

-  AC_TRY_LINK(,[inet_aton();],

-  	pr_cv_lib_standalone_aton="yes",

-	pr_cv_lib_standalone_aton="no" ))

+  AC_TRY_LINK(

+    [

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_ARPA_INET_H

+      # include <arpa/inet.h>

+      #endif

+    ],

+    [

+      inet_aton(NULL, NULL);

+    ],

+    pr_cv_lib_standalone_aton="yes",

+    pr_cv_lib_standalone_aton="no" ))

 if test "$pr_cv_lib_standalone_aton" = "no"; then

   AC_CHECK_LIB(bind, inet_aton)

 fi

 AC_CACHE_CHECK(for standalone nsl functions,pr_cv_lib_standalone_nsl,[

-  AC_TRY_LINK(,[gethostent();],

-  pr_cv_lib_standalone_nsl="yes", pr_cv_lib_standalone_nsl="no") ])

+  AC_TRY_LINK(

+    [

+      #if HAVE_NETDB_H

+      # include <netdb.h>

+      #endif

+    ],

+    [

+      gethostent();

+    ],

+    pr_cv_lib_standalone_nsl="yes",

+    pr_cv_lib_standalone_nsl="no") ])

 if test "$pr_cv_lib_standalone_nsl" = "no"; then

   AC_CHECK_LIB(nsl, gethostent)

 fi

 AC_CACHE_CHECK(for standalone socket functions,pr_cv_lib_standalone_sockets,

-  AC_TRY_LINK(,[bind();],

-  pr_cv_lib_standalone_sockets="yes", pr_cv_lib_standalone_sockets="no"))

+  AC_TRY_LINK(

+    [

+      #if HAVE_STDDEF_H

+      # include <stddef.h>

+      #endif

+      #if HAVE_SYS_SOCKET_H

+      # include <sys/socket.h>

+      #endif

+    ],

+    [

+      bind(0, NULL, 0);

+    ],

+    pr_cv_lib_standalone_sockets="yes",

+    pr_cv_lib_standalone_sockets="no"))

 if test "$pr_cv_lib_standalone_sockets" = "no"; then

   AC_CHECK_LIB(socket, bind)

-- 

2.40.1