[pangomm/cairomm-meson-improvements: 2/3] Meson/Visual Studio: Support cairomm lookup using pkg-config

[Chun-wei Fan <fanchunwei src gnome org>]

commit e369597843153077694e8debe3ba82ee13f3107e
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue May 5 15:31:33 2020 +0800

    Meson/Visual Studio: Support cairomm lookup using pkg-config
    
    cairomm recently received Meson build support, which will generate the
    pkg-config files for us, so try to look for cairomm first using
    pkg-config, before looking for it manually.
    
    Since cairomm's pkg-config file also pulls in libsigc++, we can also
    skip looking for libsigc++ if we found cairomm via pkg-config.

 meson.build | 54 ++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 34 insertions(+), 20 deletions(-)
---
diff --git a/meson.build b/meson.build
index 5ab6eed..6a54a07 100644
--- a/meson.build
+++ b/meson.build
@@ -93,36 +93,49 @@ install_pkgconfigdir = install_libdir / 'pkgconfig'
 pangocairo_req = '>= 1.41.0'
 pangocairo_dep = dependency('pangocairo', version: pangocairo_req)
 
-# glibmm recently gained Meson build support, so we can try looking
+# cairomm and glibmm recently gained Meson build support, so we can try looking
 # for its pkg-config files on Visual Studio as well
+cairomm_req = '>= 1.15.1'
 glibmm_req = '>= 2.65.1'
 
-# The -mm libraries do not yet have pkg-config files for MSVC builds,
-# so check for them manually
+# The -mm libraries may have pkg-config files for MSVC builds,
+# so check for them manually, if needed
 glibmm_req_minor_ver = '66'
 cairomm_req_minor_ver = '16'
 
+cairomm_dep = dependency('cairomm-1.@0@'.format(cairomm_req_minor_ver), version: cairomm_req, required: not 
is_msvc)
+glibmm_dep = dependency('glibmm-2.@0@'.format(glibmm_req_minor_ver), version: glibmm_req, required: not 
is_msvc)
+
 if is_msvc
   # We must have Visual Studio 2017 15.7 or later...
   assert(cpp_compiler.version().split('.')[0].to_int() >= 19 and 
cpp_compiler.version().split('.')[1].to_int() >= 15, 'Visual Studio 2017 15.7 or later is required')
 
   sigc_major_ver = '3'
 
-  glibmm_dep = dependency('glibmm-2.@0@'.format(glibmm_req_minor_ver), version: glibmm_req, required: false)
+  # The glibmm and cairomm pkg-config files pulls in libsigc++,
+  # so only look for libsigc++ if glibmm's nor cairomm's pkg-config
+  # files can't be found
+  if not glibmm_dep.found() and not cairomm_dep.found()
+    assert(cpp_compiler.has_header('sigc++-@0@.0/sigc++/sigc++.h'.format(sigc_major_ver)) and 
cpp_compiler.has_header('sigc++-@0@.0/include/sigc++config.h'.format(sigc_major_ver)),
+           'sigc++-@0@.x headers are required'.format(sigc_major_ver))
+  else
+    sigc_dep = dependency('', required: false) # cairomm/glibmm covers for libsigc++ in their pkg-config 
files
+  endif
 
   if not glibmm_dep.found()
-    assert(cpp_compiler.has_header('sigc++-@0@.0/sigc++/sigc++.h'.format(sigc_major_ver)) and \
-           cpp_compiler.has_header('sigc++-@0@.0/include/sigc++config.h'.format(sigc_major_ver)),
-           'sigc++-@0@.x headers are required')
     assert(cpp_compiler.has_header('glibmm-2.@0@/glibmm.h'.format(glibmm_req_minor_ver)) and 
cpp_compiler.has_header('glibmm-2.@0@/include/glibmmconfig.h'.format(glibmm_req_minor_ver)),
            'glibmm-2.@0@ headers are required'.format(glibmm_req_minor_ver))
-  else
-    sigc_dep = dependency ('', required: false) # glibmm covers for libsigc++ in its pkg-config file
+
   endif
 
-  assert(cpp_compiler.has_header('cairomm-1.@0@/cairomm/cairomm.h'.format(cairomm_req_minor_ver)) and 
cpp_compiler.has_header('cairomm-1.@0@/include/cairommconfig.h'.format(cairomm_req_minor_ver)),
+  if not cairomm_dep.found()
+    assert(cpp_compiler.has_header('cairomm-1.@0@/cairomm/cairomm.h'.format(cairomm_req_minor_ver)) and 
cpp_compiler.has_header('cairomm-1.@0@/include/cairommconfig.h'.format(cairomm_req_minor_ver)),
          'cairomm-1.@0@ headers are required'.format(cairomm_req_minor_ver))
-  message('Ensure your INCLUDE and LIB contain the paths that lead to the appropriate headers and .lib\'s 
for glibmm-2.@0@, cairomm-1.@1@ and libsigc++-@2@.x'.format(glibmm_req_minor_ver, cairomm_req_minor_ver, 
sigc_major_ver))
+  endif
+
+  if not glibmm_dep.found() or not cairomm_dep.found()
+    message('Ensure your INCLUDE and LIB contain the paths that lead to the appropriate headers and .lib\'s 
for glibmm-2.@0@, cairomm-1.@1@ and libsigc++-2.x'.format(glibmm_req_minor_ver, cairomm_req_minor_ver))
+  endif
 
   # Visual Studio 2019 can consume libraries built with 2017, so check for
   # 2017-built libraries as well if 2019-built libraries cannot be found
@@ -140,14 +153,14 @@ if is_msvc
   # We can be looking for MSVC 2017-built libraries on 2019 builds as well,
   # so we can't just assume that libraries exist, but check that compatible
   # versions are really found
-  cairomm_dep = dependency('', required: false)
 
   foreach v : msvc_check_range
     glibmm_dep = glibmm_dep.found() ? glibmm_dep : 
cpp_compiler.find_library('glibmm-vc@0@0@1@-2_@2@'.format(v.to_string(), debugsuffix, glibmm_req_minor_ver), 
required: false)
     cairomm_dep = cairomm_dep.found() ? cairomm_dep : 
cpp_compiler.find_library('cairomm-vc@0@0@1@-1_@2@'.format(v.to_string(), debugsuffix, 
cairomm_req_minor_ver), required: false)
   endforeach
 
-  if glibmm_dep.type_name() == 'library'
+  if glibmm_dep.type_name() == 'library' and \
+     cairomm_dep.type_name() == 'library'
     warning('Note: Be sure to check that this finds the same libsigc++ .lib your glibmm is linked to')
     sigc_dep = cpp_compiler.find_library('sigc-@0@.0'.format(sigc_major_ver), required: false)
     foreach v : msvc_check_range
@@ -156,17 +169,20 @@ if is_msvc
   endif
 
   # Now make sure the appropriate -mm libraries are found
-  assert(glibmm_dep.found() and cairomm_dep.found() and (glibmm_dep.type_name() == 'pkgconfig' or 
sigc_dep.found()), 'Appropriate glibmm-vcxx0@0@-2_@1@.lib, cairomm-vcxx0@0@-1_@2@.lib and 
sigc-vcxx0@0@-@3@_0.lib are required'.format(debugsuffix, glibmm_req_minor_ver, cairomm_req_minor_ver, 
sigc_major_ver))
+  assert(glibmm_dep.found() and cairomm_dep.found() and (glibmm_dep.type_name() == 'pkgconfig' or 
cairomm_dep.type_name() == 'pkgconfig' or sigc_dep.found()), 'Appropriate glibmm-vcxx0@0@-2_@1@.lib, 
cairomm-vcxx0@0@-1_@2@.lib and sigc-vcxx0@0@-@3@_0.lib are required'.format(debugsuffix, 
glibmm_req_minor_ver, cairomm_req_minor_ver, sigc_major_ver))
 
-  # Put glibmm in the required packages if we find it by pkg-config
-  # When cairomm gains Meson build support, we can replace
-  # this with what is done on other build systems.
+  # Put glibmm and cairomm in the required packages if we find it by pkg-config
   mm_lib_requires = ''
   if glibmm_dep.type_name() == 'pkgconfig'
     mm_lib_requires += ' '.join([
       'glibmm-2.@0@'.format(glibmm_req_minor_ver), glibmm_req,
     ]) + ' '
   endif
+  if cairomm_dep.type_name() == 'pkgconfig'
+    mm_lib_requires += ' '.join([
+      'cairomm-1.@0@'.format(cairomm_req_minor_ver), cairomm_req,
+    ]) + ' '
+  endif
 
   pangomm_requires = mm_lib_requires + ' '.join([
     'pangocairo', pangocairo_req,
@@ -174,9 +190,7 @@ if is_msvc
 
   pangomm_build_dep = [glibmm_dep, cairomm_dep, sigc_dep, pangocairo_dep]
 else
-  cairomm_req = '>= 1.15.1'
-  glibmm_dep = dependency('glibmm-2.@0@'.format(glibmm_req_minor_ver), version: glibmm_req)
-  cairomm_dep = dependency('cairomm-1.@0@'.format(cairomm_req_minor_ver), version: cairomm_req)
+  # not MSVC
   pangomm_build_dep = [glibmm_dep, cairomm_dep, pangocairo_dep]
   pangomm_requires = ' '.join([
     'glibmm-2.@0@'.format(glibmm_req_minor_ver), glibmm_req,