Côme, could you please have a look at this issue?

First, the documentation says OpenLDAP 2.4 or newer is needed: https://secure.php.net/manual/en/ldap.requirements.php

There was a discussion and a patch to make it build with solaris LDAP but it was for PHP 5.6 IIRC, not sure it’s still building: https://php.markmail.org/thread/mke5rclimfzvtaza#query:+page:1+mid:22llnz6vwjpl6sl5+state:results

Which changes would be needed to make it build with libldap.dylib?

libldap on macOS is a fork of OpenLDAP, claiming to be 2.4.28, although there are clearly some pieces of the API that have been taken out or disabled. I added a patch to the bug that just adds some configure checks to these functions and add guards around them in the source. It may not be the best solution, but I was at least able to fully compile with it.

Sorry to intervene but is using openldap from homebrew an option/alternative ?

It is but currently https://bugs.php.net/bug.php?id=76403 is blocking the project from doing just that. Can also add that if you look in the ldap.h header file macOS provides it states

LDAP_F( int )
ldap_parse_passwordpolicy_control LDAP_P((
        LDAP *ld,
        LDAPControl *ctrl,
        ber_int_t *expirep,
        ber_int_t *gracep,
        LDAPPasswordPolicyError *errorp )) __OSX_AVAILABLE_BUT_DEPRECATED_MSG(__MAC_10_0, __MAC_10_11, __IPHONE_NA, __IPHONE_NA, "use OpenDirectory Framework");

so it looks like they are trying to get people to not use openldap.

Might that be connected to https://bugs.php.net/bug.php?id=77005?

The suggestion:
"LDAP_F( int )
ldap_parse_passwordpolicy_control LDAP_P((
        LDAP *ld,
        LDAPControl *ctrl,
        ber_int_t *expirep,
        ber_int_t *gracep,
        LDAPPasswordPolicyError *errorp )) __OSX_AVAILABLE_BUT_DEPRECATED_MSG(__MAC_10_0, __MAC_10_11, __IPHONE_NA, __IPHONE_NA, "use OpenDirectory Framework");
"

Do not work with 
System Version: OS X 10.11.6
Kernel Version: Darwin 15.6.0

Applied in files below, but without success:


/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift-migrator/sdks/MacOSX.sdk/usr/include/ldap.h
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/ldap.h
/usr/include/ldap.h
/usr/local/Cellar/openldap/2.4.47/include/ldap.h
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/ldap.h

openLdap version: 
$OpenLDAP: ldapmodify 2.4.28 (Oct  3 2015 17:40:55)

Hello,

The patch macos-ldap (last revision 2018-06-11 17:57 UTC by kevin dot abel dot 0 at gmail dot com) do not work with :
System Version: OS X 10.11.6
Kernel Version: Darwin 15.6.0

php-7.3.4.tar.gz
httpd-2.4.39.tar.gz
OpenLDAP: ldapmodify 2.4.28 (Oct  3 2015 17:40:55)


Error:
Undefined symbols for architecture x86_64:
  "_ldap_create_sort_control_value", referenced from:
      __php_ldap_control_from_array in ldap.o
  "_ldap_create_vlv_control_value", referenced from:
      __php_ldap_control_from_array in ldap.o
ld: symbol(s) not found for architecture x86_64


It's seems only solves the issue about "_ldap_create_passwordpolicy_control" and "ldap_parse_passwordpolicy_control" symbols.

ldap_create_sort_control_value definitely exists in OpenLDAP 2.4.28, are you sure this is what you are linking against?