[gtk] meson: cups: use cups-config for looking up cups

[Christoph Reiter <creiter src gnome org>]

commit 72814c54a81195a76c96990987c71680096e905c
Author: Christoph Reiter <creiter src gnome org>
Date:   Mon Jul 1 21:52:06 2019 +0200

    meson: cups: use cups-config for looking up cups
    
    We were looking for the cups headers and the cups lib in the default locations
    which for example breaks with OpenBSD where the cups headers are under /usr/local/include/
    
    Instead just use the "cups" dependency type from meson which internally uses cups-config.
    
    See #1967
    
    Ported to master from !963

 modules/printbackends/meson.build | 22 +++-------------------
 1 file changed, 3 insertions(+), 19 deletions(-)
---
diff --git a/modules/printbackends/meson.build b/modules/printbackends/meson.build
index 2946960d2e..c8c56454d6 100644
--- a/modules/printbackends/meson.build
+++ b/modules/printbackends/meson.build
@@ -17,24 +17,8 @@ print_backends = ['file']
 # Checks to see if we should compile with CUPS backend for GTK
 enable_cups = enabled_print_backends.contains('cups')
 if enable_cups
-  #cups_config = find_program('cups-config', required : true)
-  #if cups_config.found()
-  # FIXME: eek, see configure.ac (we're just not going to support non-standar prefix for now)
-  #endif
-  if cc.has_header('cups/cups.h')
-    # TODO: include_directories from cups-config
-    cups_major_version = cc.compute_int('CUPS_VERSION_MAJOR', prefix : '#include <cups/cups.h>')
-    cups_minor_version = cc.compute_int('CUPS_VERSION_MINOR', prefix : '#include <cups/cups.h>')
-    message('Found CUPS version: @0@.@1@'.format(cups_major_version, cups_minor_version))
-    if cups_major_version < 2
-      cups_error = 'Need CUPS version >= 2.0'
-    else
-      libcups = cc.find_library('cups', required : true)
-      print_backends += ['cups']
-    endif
-  else
-    error('Cannot find CUPS headers in default prefix.')
-  endif
+  cups_dep = dependency('cups', version : '>=2.0', required: true)
+  print_backends += ['cups']
 endif
 
 # Checks to see if we should compile with cloudprint backend for GTK
@@ -93,7 +77,7 @@ if print_backends.contains('cups')
                 'gtkcupsutils.c',
                 'gtkcupssecretsutils.c',
                 c_args: printbackends_args,
-                dependencies: [libgtk_dep, libcups, colord_dep],
+                dependencies: [libgtk_dep, cups_dep, colord_dep],
                 install_dir: printbackends_install_dir,
                 install : true)
 endif