build: check for gpgme with pkg-config before gpgme-config

gpgme in git master now supports pkg-config and with the next release we
can and should prefer its use. However, retain the legacy code that
enables building with older versions of gpgme, as a fallback.

Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

configure.ac

@@ -268,7 +268,11 @@ AS_IF([test "x$with_gpgme" != "xno"],
 	[AC_MSG_RESULT([no])])
 
 have_gpgme=no
-AS_IF([test "x$with_gpgme" != "xno"],
+if test "x$with_gpgme" != "xno"; then
+	PKG_CHECK_MODULES(GPGME, [gpgme],
+		[AC_DEFINE([HAVE_LIBGPGME], [1], [Define if gpgme should be used to provide GPG signature support.])
+		AC_SUBST(pc_gpgme, [gpgme])
+		have_gpgme=yes],
 		[AM_PATH_GPGME([1.3.0],
 			[LIBS_save="$LIBS"
 			CPPFLAGS_save="$CPPFLAGS"
@@ -285,7 +289,8 @@ AS_IF([test "x$with_gpgme" != "xno"],
 					[[return gpgme_check_version("1.3.0");]])],
 				[AC_MSG_RESULT([yes])
 				have_gpgme=yes
-			AC_DEFINE([HAVE_LIBGPGME], [1], [Define if gpgme should be used to provide GPG signature support.])],
+				AC_DEFINE([HAVE_LIBGPGME], [1], [Define if gpgme should be used to provide GPG signature support.])
+				AC_SUBST(pc_gpgme_libs, ["$GPGME_LIBS"])],
 				[AC_MSG_RESULT([no])
 				have_gpgme=no
 				unset GPGME_LIBS
@@ -299,6 +304,7 @@ AS_IF([test "x$with_gpgme" != "xno"],
 			CFLAGS="$CFLAGS_save"
 			unset CPPFLAGS_save
 			unset CFLAGS_save],)])
+fi
 
 AS_IF([test "x$have_gpgme" = xno -a "x$with_gpgme" = xyes],
 	[AC_MSG_FAILURE([--with-gpgme was given, but gpgme was not found])])

lib/libalpm/libalpm.pc.in

@@ -7,7 +7,7 @@ Name: libalpm
 Description: Arch Linux package management library
 URL: http://www.archlinux.org/pacman/
 Version: @LIB_VERSION@
-Requires.private: libarchive @pc_crypto@ @pc_libcurl@
+Requires.private: libarchive @pc_crypto@ @pc_libcurl@ @pc_gpgme@
 Cflags: -I${includedir} @LFS_CFLAGS@
 Libs: -L${libdir} -lalpm
-Libs.private: @LIBS@ @GPGME_LIBS@
+Libs.private: @LIBS@ @pc_gpgme_libs@

meson.build

@@ -98,29 +98,34 @@ libcurl = dependency('libcurl',
 conf.set('HAVE_LIBCURL', libcurl.found())
 
 want_gpgme = get_option('gpgme')
-gpgme_config = find_program('gpgme-config', required : want_gpgme)
+gpgme = dependency('gpgme',
-if not want_gpgme.disabled() and gpgme_config.found()
+                   required : false,
+                   static : get_option('buildstatic'))
+# gpgme recently began providing a pkg-config file. Create a fake dependency
+# object if it cannot be found, by manually searching for libs.
+if not want_gpgme.disabled() and not gpgme.found()
+  gpgme_config = find_program('gpgme-config', required : want_gpgme)
+  if gpgme_config.found()
     gpgme_version = run_command(gpgme_config, '--version').stdout().strip()
 
     needed_gpgme_version = '>=1.3.0'
-  have = gpgme_version.version_compare(needed_gpgme_version)
+    if gpgme_version.version_compare(needed_gpgme_version)
-  if want_gpgme.enabled() and not have
-    error('gpgme @0@ is needed for GPG signature support'.format(needed_gpgme_version))
-  endif
-
       gpgme_libs = [
-    cc.find_library('gpgme', required : have,
+        cc.find_library('gpgme',
                         dirs : [get_option('gpgme-libdir')]),
-    cc.find_library('gpg-error', required : have,
+        cc.find_library('gpg-error',
                         dirs : [get_option('gpgme-libdir')]),
-    cc.find_library('assuan', required : have,
+        cc.find_library('assuan',
                         dirs : [get_option('gpgme-libdir')]),
       ]
+      gpgme = declare_dependency(dependencies : gpgme_libs)
+    endif
+  endif
+endif
 
-  conf.set('HAVE_LIBGPGME', have)
+conf.set('HAVE_LIBGPGME', gpgme.found())
-else
+if want_gpgme.enabled() and not conf.get('HAVE_LIBGPGME')
-  gpgme_libs = []
+  error('gpgme @0@ is needed for GPG signature support'.format(needed_gpgme_version))
-  conf.set('HAVE_LIBGPGME', false)
 endif
 
 want_crypto = get_option('crypto')
@@ -341,7 +346,7 @@ libalpm_a = static_library(
   'alpm',
   libalpm_sources,
   include_directories : includes,
-  dependencies : [crypto_provider, libarchive, libcurl] + gpgme_libs,
+  dependencies : [crypto_provider, libarchive, libcurl, gpgme],
   link_with : [libcommon],
   install : true)