Update autoconf script

[Girgias]

Fixes autoconf warnings

[nikic]

libtool.m4 is a bundled file.

[Girgias]

I cloned the latest version of libtools and it seems those issues are fixed, but I'm not sure how I'm meant to upgrade our bundled copy.

[cmb69]

Ugh, looks like we're having a patched libtool.m4 1.5.26 (which was released 14 years ago).

[arnaud-lb]

Fortunately the diff is not huge: https://gist.github.com/arnaud-lb/71a04e27eb3699a534defe0871bfa3cd. Some the changes do not appear to exist in the latest libtool, but others are cosmetic or backports.

[petk]

Suggested change

	AC_PREREQ([2.69])
	AC_PREREQ([2.68])

I'd leave this for now as it is.

[petk]

Suggested change

	AC_LINK_IFELSE(
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[lt_cv_cc_needs_belf=yes],[lt_cv_cc_needs_belf=no])

In one line it is simpler to compare it with possible upstream version.

[petk]

I'd also add this one:

@@ -271,7 +271,7 @@ $rm -r conftest*
 
 dnl autoconf 2.13 compatibility
 dnl _LT_AC_TRY_LINK()
-AC_DEFUN(_LT_AC_TRY_LINK, [
+AC_DEFUN([_LT_AC_TRY_LINK], [
 cat > conftest.$ac_ext <<EOF
 dnl This sometimes fails to find confdefs.h, for some reason.
 dnl [#]line __oline__ "[$]0"

[petk]

For the libtool.m4 file upgrade I'd suggest that PHP stays with a forked Libtool 1.5.26. Upgrade to the latest 2.4.x version is possible but contains so many annoyances and possible breakages that I don't think is worth of trouble. And another issue is that this latest libtool 2.4.x would also need some heavy patching from various places and pull requests. Maintenance at GNU hasn't followed all the requests out there.

We've already discussed this in the past, btw.

This is how unbundling libtool would look like approximately:

• Unbundle libtool #4359

And this is how upgrade would look like approximately:

• Upgrade libtool #4358

[andypost]

Used to apply as patch and build on Alpinelinux - all warnings are gone!

Meantime when I build apache2 SAPI (--with-apxs2) I see some debug listed, checked build logs and looks it's here last few years

example https://gitlab.alpinelinux.org/andypost/aports/-/jobs/1006143

Configuring SAPI modules
checking for Apache 2 handler module support via DSO through APXS... APACHE_CFLAGS=' -I/usr/include/apache2   -DLINUX -D_REENTRANT -D_GNU_SOURCE -I/usr/include/apr-1   -I/usr/include/apr-1  -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1'
APORTSDIR='/mnt'
APR_BINDIR='/usr/bin'
APR_CFLAGS='  -DLINUX -D_REENTRANT -D_GNU_SOURCE -I/usr/include/apr-1 '
APR_CONFIG='/usr/bin/apr-1-config'
APU_BINDIR='/usr/bin'
APU_CFLAGS=' -I/usr/include/apr-1 '
APU_CONFIG='/usr/bin/apu-1-config'
APXS='apxs'
APXS_BINDIR='/usr/bin'
APXS_CFLAGS='-Os -fomit-frame-pointer'
APXS_HTTPD='/usr/sbin/httpd'
APXS_INCLUDEDIR='/usr/include/apache2'
...

[andypost]

What's left here to make it commitable?

[Girgias]

Everything? I don't understand libtools nor how we should go about updating our built-in libtools.

I'm going to close this as I don't know how I can proceed but feel free to open a new PR as you seems to have more expertise in build systems than I do.

[petk]

I'll make a patch for this issue: #11207