According to openpty(3) it is required to include <pty.h> to get the
prototypes for openpty() and login_tty(). But this is not what the
function AX_CHECK_PTYFUNCS actually does. It makes no attempt to include
the required header.

The two source files which call openpty() and login_tty() already contain
the conditionals to include the required header.

Remove the bogus m4 file to fix build with clang, which complains about
calls to undeclared functions.

Remove usage of INCLUDE_LIBUTIL_H in libxl_bootloader.c, it is already
covered by inclusion of libxl_osdep.h.

Remove usage of PTYFUNCS_LIBS in libxl/Makefile, it is already covered
by UTIL_LIBS from config/StdGNU.mk.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
v2: remove consumers of the macros

 config/Tools.mk.in                  |  2 --
 m4/ptyfuncs.m4                      | 35 -----------------------------
 tools/configure.ac                  |  2 --
 tools/libs/light/Makefile           |  2 +-
 tools/libs/light/libxl_bootloader.c |  4 ----
 5 files changed, 1 insertion(+), 44 deletions(-)
 delete mode 100644 m4/ptyfuncs.m4

diff --git a/config/Tools.mk.in b/config/Tools.mk.in
index 6abb377564..b7cc2961d8 100644
--- a/config/Tools.mk.in
+++ b/config/Tools.mk.in
@@ -31,8 +31,6 @@ PTHREAD_CFLAGS      := @PTHREAD_CFLAGS@
 PTHREAD_LDFLAGS     := @PTHREAD_LDFLAGS@
 PTHREAD_LIBS        := @PTHREAD_LIBS@
 
-PTYFUNCS_LIBS       := @PTYFUNCS_LIBS@
-
 LIBNL3_LIBS         := @LIBNL3_LIBS@
 LIBNL3_CFLAGS       := @LIBNL3_CFLAGS@
 XEN_TOOLS_RPATH     := @rpath@
diff --git a/m4/ptyfuncs.m4 b/m4/ptyfuncs.m4
deleted file mode 100644
index 3e37b5a23c..0000000000
--- a/m4/ptyfuncs.m4
+++ /dev/null
@@ -1,35 +0,0 @@
-AC_DEFUN([AX_CHECK_PTYFUNCS], [
-    dnl This is a workaround for a bug in Debian package
-    dnl libbsd-dev-0.3.0-1. Once we no longer support that
-    dnl package we can remove the addition of -Werror to
-    dnl CPPFLAGS.
-    AX_SAVEVAR_SAVE(CPPFLAGS)
-    CPPFLAGS="$CPPFLAGS -Werror"
-    AC_CHECK_HEADER([libutil.h],[
-      AC_DEFINE([INCLUDE_LIBUTIL_H],[<libutil.h>],[libutil header file name])
-    ])
-    AX_SAVEVAR_RESTORE(CPPFLAGS)
-    AC_CACHE_CHECK([for openpty et al], [ax_cv_ptyfuncs_libs], [
-        for ax_cv_ptyfuncs_libs in -lutil "" NOT_FOUND; do
-            if test "x$ax_cv_ptyfuncs_libs" = "xNOT_FOUND"; then
-                AC_MSG_FAILURE([Unable to find library for openpty and login_tty])
-            fi
-            AX_SAVEVAR_SAVE(LIBS)
-            LIBS="$LIBS $ax_cv_ptyfuncs_libs"
-            AC_LINK_IFELSE([AC_LANG_SOURCE([
-#ifdef INCLUDE_LIBUTIL_H
-#include INCLUDE_LIBUTIL_H
-#endif
-int main(void) {
-  openpty(0,0,0,0,0);
-  login_tty(0);
-}
-])],[
-                break
-            ],[])
-            AX_SAVEVAR_RESTORE(LIBS)
-        done
-    ])
-    PTYFUNCS_LIBS="$ax_cv_ptyfuncs_libs"
-    AC_SUBST(PTYFUNCS_LIBS)
-])
diff --git a/tools/configure.ac b/tools/configure.ac
index 9bcf42f233..3cccf41960 100644
--- a/tools/configure.ac
+++ b/tools/configure.ac
@@ -70,7 +70,6 @@ m4_include([../m4/uuid.m4])
 m4_include([../m4/pkg.m4])
 m4_include([../m4/curses.m4])
 m4_include([../m4/pthread.m4])
-m4_include([../m4/ptyfuncs.m4])
 m4_include([../m4/extfs.m4])
 m4_include([../m4/fetcher.m4])
 m4_include([../m4/ax_compare_version.m4])
@@ -416,7 +415,6 @@ AC_SUBST([ZLIB_CFLAGS])
 AC_SUBST([ZLIB_LIBS])
 AX_CHECK_EXTFS
 AX_CHECK_PTHREAD
-AX_CHECK_PTYFUNCS
 AC_CHECK_LIB([yajl], [yajl_alloc], [],
     [AC_MSG_ERROR([Could not find yajl])])
 AC_CHECK_LIB([z], [deflateCopy], [], [AC_MSG_ERROR([Could not find zlib])])
diff --git a/tools/libs/light/Makefile b/tools/libs/light/Makefile
index 96daeabc47..5d7ff94b05 100644
--- a/tools/libs/light/Makefile
+++ b/tools/libs/light/Makefile
@@ -158,7 +158,7 @@ NO_HEADERS_CHK := y
 
 include $(XEN_ROOT)/tools/libs/libs.mk
 
-LDLIBS-y += $(PTYFUNCS_LIBS)
+LDLIBS-y += $(UTIL_LIBS)
 LDLIBS-$(CONFIG_LIBNL) += $(LIBNL3_LIBS)
 LDLIBS-$(CONFIG_Linux) += -luuid
 LDLIBS-$(CONFIG_Linux) += -lrt
diff --git a/tools/libs/light/libxl_bootloader.c b/tools/libs/light/libxl_bootloader.c
index 18e9ebd714..1bc6e51827 100644
--- a/tools/libs/light/libxl_bootloader.c
+++ b/tools/libs/light/libxl_bootloader.c
@@ -19,10 +19,6 @@
 #include <utmp.h>
 #endif
 
-#ifdef INCLUDE_LIBUTIL_H
-#include INCLUDE_LIBUTIL_H
-#endif
-
 #include "libxl_internal.h"
 
 #define BOOTLOADER_BUF_OUT 65536

On Fri, May 12, 2023 at 12:26:14PM +0000, Olaf Hering wrote:
> According to openpty(3) it is required to include <pty.h> to get the
> prototypes for openpty() and login_tty(). But this is not what the
> function AX_CHECK_PTYFUNCS actually does. It makes no attempt to include
> the required header.
> 
> The two source files which call openpty() and login_tty() already contain
> the conditionals to include the required header.
> 
> Remove the bogus m4 file to fix build with clang, which complains about
> calls to undeclared functions.
> 
> Remove usage of INCLUDE_LIBUTIL_H in libxl_bootloader.c, it is already
> covered by inclusion of libxl_osdep.h.
> 
> Remove usage of PTYFUNCS_LIBS in libxl/Makefile, it is already covered
> by UTIL_LIBS from config/StdGNU.mk.
> 
> Signed-off-by: Olaf Hering <olaf@aepfle.de>

Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

Obviously, the committer will have to run ./autogen.sh before
committing.

Thanks,

-- 
Anthony PERARD