[WIP] Add PHP pkgconf .pc metadata file(s)

Since PHP *nix Autotools build system already extensively relies on
pkgconf (pkg-config) command-line tool to find dependencies it should
also provide its own .pc metadata file(s). [1]

This adds an initial php.pc.in and php-embed.pc.in templates that are
created during the configuration and build phase. They are installed in
the provided system pkgconfig directory. For example:

    /usr/lib/pkgconfig/php.pc
    /usr/lib/pkgconfig/php-embed.pc
    /usr/lib/pkgconfig/php-embed8.pc
    /usr/lib/pkgconfig/php-embed8.4.pc
    /usr/lib/x86_64-linux-gnu/pkgconfig/php.pc

Pkgconf [2] is a more actively maintained continuation of the initial
Freedesktop's pkg-config project [3].

Extensions and applications embedding the PHP Embed SAPI can then
optionally use also the pkgconf utility to get the required PHP CFLAGS
and/or LIBS.

Extensions can use:

    pkgconf --cflags php
    pkgconf --libs php
    pkgconf --modversion php
    pkgconf --cflags php8.4

Applications embedding the PHP Embed SAPI:

    pkgconf --libs php-embed
    pkgconf --cflags php-embed
    pkgconf --modversion php-embed
    pkgconf --cflags php-embed8.4

[1]: https://people.freedesktop.org/~dbn/pkg-config-guide.html
[2]: https://github.com/pkgconf/pkgconf
[3]: https://gitlab.freedesktop.org/pkg-config/pkg-config

Author: petk

.gitignore

@@ -112,6 +112,7 @@ config.h.in
 # SAPIs specific ignores
 # ------------------------------------------------------------------------------
 /sapi/apache2handler/libphp.module
+/sapi/embed/php-embed.pc
 /sapi/fpm/fpm/php-cgi
 /sapi/fpm/init.d.php-fpm
 /sapi/fpm/php-fpm.conf
@@ -129,6 +130,7 @@ config.h.in
 /sapi/fpm/php-fpm
 /sapi/phpdbg/phpdbg
 /scripts/php-config
+/scripts/php.pc
 /scripts/phpize
 php
 

configure.ac

@@ -1666,7 +1666,7 @@ else
 fi;
 
 all_targets="\$(OVERALL_TARGET) \$(PHP_MODULES) \$(PHP_ZEND_EX) \$(PHP_BINARIES) $pharcmd"
-install_targets="$install_sapi $install_modules $install_binaries install-build install-headers install-programs $install_pear $pharcmd_install"
+install_targets="$install_sapi $install_modules $install_binaries install-build install-headers install-programs $install_pear $pharcmd_install $install_embed"
 
 PHP_SUBST(all_targets)
 PHP_SUBST(install_targets)
@@ -1761,7 +1761,7 @@ $php_shtool mkdir -p scripts
 $php_shtool mkdir -p scripts/man1
 
 ALL_OUTPUT_FILES="main/build-defs.h \
-scripts/phpize scripts/man1/phpize.1 \
+scripts/php.pc scripts/phpize scripts/man1/phpize.1 \
 scripts/php-config scripts/man1/php-config.1 \
 $PHP_OUTPUT_FILES"
 

sapi/embed/Makefile.frag

@@ -0,0 +1,4 @@
+install-embed:
+	@echo "Installing PHP Embed SAPI:         $(INSTALL_ROOT)$(libdir)"
+	@$(mkinstalldirs) $(INSTALL_ROOT)$(libdir)/pkgconfig
+	@$(INSTALL_DATA) sapi/embed/php-embed.pc $(INSTALL_ROOT)$(libdir)/pkgconfig/$(program_prefix)php-embed$(program_suffix).pc

sapi/embed/config.m4

@@ -29,6 +29,11 @@ if test "$PHP_EMBED" != "no"; then
     PHP_INSTALL_HEADERS([sapi/embed], [php_embed.h])
   fi
   AC_MSG_RESULT([$PHP_EMBED_TYPE])
+
+  PHP_ADD_MAKEFILE_FRAGMENT([$abs_srcdir/sapi/embed/Makefile.frag], [$abs_srcdir/sapi/embed], [$abs_builddir/sapi/embed])
+  PHP_OUTPUT([sapi/embed/php-embed.pc])
+
+  install_embed=install-embed
 else
   AC_MSG_RESULT(no)
 fi

sapi/embed/php-embed.pc.in

@@ -0,0 +1,18 @@
+# The .pc file for pkgconf (pkg-config) utility.
+# https://github.com/pkgconf/pkgconf
+# https://people.freedesktop.org/~dbn/pkg-config-guide.html
+
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+includedir=@prefix@/include
+libdir=@exec_prefix@/lib
+
+Name: PHP Embed SAPI
+Description: Embed PHP into application with C bindings using a lightweight SAPI
+URL: https://www.php.net
+License: PHP
+Version: @PHP_VERSION@
+Cflags.private: @PHP_CFLAGS_PRIVATE@
+Cflags: -I${includedir} -I${includedir}/main -I${includedir}/TSRM -I${includedir}/Zend -I${includedir}/ext -I${includedir}/ext/date/lib
+Libs.private: @PHP_LIBS_PRIVATE@
+Libs: -L${libdir} -lphp

scripts/Makefile.frag

@@ -46,6 +46,9 @@ install-programs: $(builddir)/phpize $(builddir)/php-config
 		echo "  page: $(program_prefix)$${page}$(program_suffix).1"; \
 		$(INSTALL_DATA) $(builddir)/man1/$${page}.1 $(INSTALL_ROOT)$(mandir)/man1/$(program_prefix)$${page}$(program_suffix).1; \
 	done
+	@echo "Installing pkgconf .pc file:       $(INSTALL_ROOT)$(libdir)/pkgconfig/php.pc"
+	@$(mkinstalldirs) $(INSTALL_ROOT)$(libdir)/pkgconfig
+	@$(INSTALL_DATA) $(builddir)/php.pc $(INSTALL_ROOT)$(libdir)/pkgconfig/$(program_prefix)php$(program_suffix).pc
 
 $(builddir)/phpize: $(srcdir)/phpize.in $(top_builddir)/config.status
 	(CONFIG_FILES=$@ CONFIG_HEADERS= $(top_builddir)/config.status)

scripts/php.pc.in

@@ -0,0 +1,16 @@
+# The .pc file for pkgconf (pkg-config) utility.
+# https://github.com/pkgconf/pkgconf
+# https://people.freedesktop.org/~dbn/pkg-config-guide.html
+
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+includedir=@prefix@/include
+libdir=@exec_prefix@/lib
+
+Name: PHP
+Description: A general-purpose scripting language
+URL: https://www.php.net
+License: PHP
+Version: @PHP_VERSION@
+CFlags: -I${includedir} -I${includedir}/main -I${includedir}/TSRM -I${includedir}/Zend -I${includedir}/ext -I${includedir}/ext/date/lib
+Libs: -L${libdir} -lphp