[pangomm/cairomm-meson-improvements-2-42: 2/4] Meson/Visual Studio: Support cairomm lookup using pkg-config

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

commit fcba75be387521c0bfb353a96f3201d1c6d39295
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 | 47 +++++++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 16 deletions(-)
---
diff --git a/meson.build b/meson.build
index fd13388..7f23903 100644
--- a/meson.build
+++ b/meson.build
@@ -88,8 +88,9 @@ install_pkgconfigdir = install_libdir / 'pkgconfig'
 # pangomm_dep (created in pango/pangomm/meson.build):
 #   Dependencies when using the pangomm library.
 
-# 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 = '>= 1.2.2'
 glibmm_req = '>= 2.48.0'
 
 # Pango supported pkg-config files on MSVC files for a good while,
@@ -97,11 +98,12 @@ glibmm_req = '>= 2.48.0'
 pangocairo_req = '>= 1.41.0'
 pangocairo_dep = dependency('pangocairo', version: pangocairo_req)
 
-# 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 = '4'
 cairomm_req_minor_ver = '0'
 
+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)
 
 # Where to find gmmproc and generate_wrap_init.pl.
@@ -118,18 +120,30 @@ if is_msvc
 
   sigc_major_ver = '2'
 
-  if not glibmm_dep.found()
+  # 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('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))
+  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
 
   # We need to look for appropriate versions of Visual
   # Studio since those built by NMake and the former
@@ -152,7 +166,6 @@ if is_msvc
   # We can be looking for MSVC 2015-built libraries on 2017 and 2019 builds as well,
   # as well as 2017-built libraries on 2019 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)
@@ -162,7 +175,8 @@ if is_msvc
   # Check whether we compile pangomm without using gendef
   build_shared_libs_directly = false
 
-  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
@@ -171,17 +185,20 @@ 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,
@@ -190,8 +207,6 @@ if is_msvc
   pangomm_build_dep = [glibmm_dep, cairomm_dep, sigc_dep, pangocairo_dep]
 else
   # not MSVC
-  cairomm_req = '>= 1.2.2'
-  cairomm_dep = dependency('cairomm-1.@0@'.format(cairomm_req_minor_ver), version: cairomm_req)
   pangomm_build_dep = [glibmm_dep, cairomm_dep, pangocairo_dep]
   pangomm_requires = ' '.join([
     'glibmm-2.@0@'.format(glibmm_req_minor_ver), glibmm_req,