[atk: 16/19] build: Simplify GObject dependency discovery

[Emmanuele Bassi <ebassi src gnome org>]

commit 2f531e76cfe129d01dd8f9aeab1c9fc2d69f5bee
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon May 22 12:50:45 2017 +0100

    build: Simplify GObject dependency discovery
    
    We don't need this much ad hoc complexity in the build system to find
    gobject-2.0 and its tools.
    
    GObject depends on GLib; GThread does not exist any more, as has been
    subsumed into GLib; the AM_PATH_GLIB_2_0 m4 macro is deprecated in
    favour of just using PKG_CHECK_MODULES.

 atk.pc.in    |    2 +-
 configure.ac |   29 ++++++++---------------------
 meson.build  |    1 -
 3 files changed, 9 insertions(+), 23 deletions(-)
---
diff --git a/atk.pc.in b/atk.pc.in
index 39aa30e..51ce841 100644
--- a/atk.pc.in
+++ b/atk.pc.in
@@ -6,6 +6,6 @@ includedir=@includedir@
 Name: Atk
 Description: Accessibility Toolkit
 Version: @VERSION@
-Requires: @GLIB_PACKAGES@
+Requires: gobject-2.0
 Libs: -L${libdir} -latk-@ATK_API_VERSION@
 Cflags: -I${includedir}/atk-1.0
diff --git a/configure.ac b/configure.ac
index 870844b..6d6b986 100644
--- a/configure.ac
+++ b/configure.ac
@@ -161,29 +161,16 @@ fi
 changequote([,])dnl
 
 GLIB_REQUIRED_VERSION=2.31.2
-GLIB_PACKAGES="gobject-2.0"
-AC_SUBST(GLIB_PACKAGES)
 AC_SUBST(GLIB_REQUIRED_VERSION)
 
-dnl This PATH_GLIB is somewhat redundant, but does a sanity compile and 
-dnl importantly defines the GLIB_GENMARSHAL variable for subst into the
-dnl Makefile
-AM_PATH_GLIB_2_0($GLIB_REQUIRED_VERSION, :,
-  AC_MSG_ERROR([
-*** GLIB $GLIB_REQUIRED_VERSION or better is required. The latest version of 
-*** GLIB is always available from ftp://ftp.gtk.org/. If GLIB is installed
-*** but not in the same location as pkg-config add the location of the file 
-*** glib-2.0.pc to the environment variable PKG_CONFIG_PATH.]),
-  gobject)
-
-PKG_CHECK_MODULES(DEP, glib-2.0 >= $GLIB_REQUIRED_VERSION $GLIB_PACKAGES, ,
-  AC_MSG_ERROR([
-        *** GLib not found. You can find it on ftp://ftp.gtk.org
-        *** Errors follow:
-            $DEP_PKG_ERRORS]))
-
-# Rerun PKG_CONFIG to add gthread-2.0 cflags, but not libs
-DEP_CFLAGS=`$PKG_CONFIG --cflags $GLIB_PACKAGES gthread-2.0`
+PKG_CHECK_MODULES(DEP, [gobject-2.0 >= $GLIB_REQUIRED_VERSION])
+AC_SUBST(DEP_CFLAGS)
+AC_SUBST(DEP_LIBS)
+
+GLIB_MKENUMS=`$PKG_CONFIG --variable=glib_mkenums glib-2.0`
+GLIB_GENMARSHAL=`$PKG_CONFIG --variable=glib_genmarshal glib-2.0`
+AC_SUBST(GLIB_MKENUMS)
+AC_SUBST(GLIB_GENMARSHAL)
 
 # i18n stuff
 AM_GNU_GETTEXT_VERSION([0.19.2])
diff --git a/meson.build b/meson.build
index ada80f3..1fd2ed5 100644
--- a/meson.build
+++ b/meson.build
@@ -103,7 +103,6 @@ pkgconf.set('exec_prefix', atk_prefix)
 pkgconf.set('libdir', atk_libdir)
 pkgconf.set('includedir', atk_includedir)
 pkgconf.set('VERSION', meson.project_version())
-pkgconf.set('GLIB_PACKAGES', 'gobject-2.0')
 pkgconf.set('ATK_API_VERSION', atk_api_version)
 pkgconf.set('srcdir', '.')