Add PHP pkg-config .pc metadata files

Since PHP *nix Autotools build system already extensively relies on
pkgconf (pkg-config) command-line tool to find dependencies it should
also provide its .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 maintained continuation of the initial Freedesktop's
pkg-config project [3].

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

For PHP extensions:

    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
 

build/php.m4

@@ -2536,3 +2536,16 @@ AS_VAR_IF([php_var], [yes],
     [Define to 1 if the compiler supports the '$1' variable attribute.])])
 AS_VAR_POPDEF([php_var])
 ])
+
+dnl
+dnl PHP_SET_LIBS_PRIVATE
+dnl
+dnl Get a list of all external libraries that were linked to PHP. For using in
+dnl templates, such as php.pc.in.
+dnl
+AC_DEFUN([PHP_SET_LIBS_PRIVATE],
+[PHP_LIBS_PRIVATE=$EXTRA_LIBS
+AS_VAR_SET_IF([ZEND_EXTRA_LIBS],
+  [AS_VAR_APPEND([PHP_LIBS_PRIVATE], [" $ZEND_EXTRA_LIBS"])])
+AC_SUBST([PHP_LIBS_PRIVATE])
+])

configure.ac

@@ -1328,6 +1328,8 @@ EXTRA_LDFLAGS="$EXTRA_LDFLAGS $LDFLAGS"
 EXTRA_LDFLAGS_PROGRAM="$EXTRA_LDFLAGS_PROGRAM $LDFLAGS"
 unset LDFLAGS
 
+PHP_SET_LIBS_PRIVATE
+
 AC_ARG_PROGRAM
 
 AS_VAR_IF([prefix], [NONE], [prefix=/usr/local])
@@ -1630,7 +1632,7 @@ 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])
@@ -1784,7 +1786,7 @@ PHP_ADD_BUILD_DIR([m4_normalize([
 ])])
 
 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

@@ -30,6 +30,11 @@ if test "$PHP_EMBED" != "no"; then
   fi
   AC_MSG_RESULT([$PHP_EMBED_TYPE])
   AC_SUBST([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 +1,33 @@
+# The .pc file for pkg-config command-line utility.
+# https://en.wikipedia.org/wiki/Pkg-config
+#
+# Usage:
+#   pkg-config --cflags php-embed
+#   pkg-config --cflags-only-I php-embed
+#   pkg-config --libs php-embed
+#   pkg-config --mod-version php-embed
+#   pkg-config --print-variables php-embed
+#   pkg-config --variable=php_vernum php-embed
+
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+includedir=@includedir@/php
+libdir=@exec_prefix@/lib
+# The extension_dir PHP INI directive absolute path.
+extensiondir=@PHP_EXTENSION_DIR@
+# PHP version as integer.
+php_vernum=@PHP_VERSION_ID@
+# The path where to scan for additional INI configuration files.
+php_inidir=@PHP_CONFIG_FILE_SCAN_DIR@
+# The path in which to look for php.ini.
+php_inipath=@PHP_CONFIG_FILE_PATH@
+
+Name: PHP Embed SAPI
+Description: A lightweight SAPI to embed PHP into application using C bindings
+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 +1,33 @@
+# The .pc file for pkg-config command-line utility.
+# https://en.wikipedia.org/wiki/Pkg-config
+#
+# Usage:
+#   pkg-config --cflags php
+#   pkg-config --cflags-only-I php
+#   pkg-config --libs php
+#   pkg-config --mod-version php
+#   pkg-config --print-variables php
+#   pkg-config --variable=php_vernum php
+
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+includedir=@includedir@/php
+libdir=@exec_prefix@/lib
+# The extension_dir PHP INI directive absolute path.
+extensiondir=@PHP_EXTENSION_DIR@
+# PHP version as integer.
+php_vernum=@PHP_VERSION_ID@
+# The path where to scan for additional INI configuration files.
+php_inidir=@PHP_CONFIG_FILE_SCAN_DIR@
+# The path in which to look for php.ini.
+php_inipath=@PHP_CONFIG_FILE_PATH@
+
+Name: PHP
+Description: Build extension for a PHP general-purpose scripting language
+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: