[pangomm/meson.msvc: 1/6] meson: Check for -mm deps manually on MSVC

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

commit 2a4fb0131eb5f814d2aeaf208a4d2b3de8b2b533
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Thu Sep 19 18:34:25 2019 +0800

    meson: Check for -mm deps manually on MSVC
    
    The MSVC build files for the -mm library dependencies do not generate
    pkg-config files, so check for them manually.  This can be eventually
    replaced by the pkg-config checks when these dependencies gain
    Meson build support for MSVC.
    
    This will build and link pangomm without the import libraries, which
    will require us to build and use gendef.exe that is in
    MSVC_NMake/gendef, which will be done in a later commit.

 meson.build | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 73 insertions(+), 12 deletions(-)
---
diff --git a/meson.build b/meson.build
index 0367a39..08d5935 100644
--- a/meson.build
+++ b/meson.build
@@ -90,18 +90,77 @@ install_pkgconfigdir = install_libdir / 'pkgconfig'
 # pangomm_build_dep: Dependencies when building the pangomm library.
 # pangomm_dep (created in pango/pangomm/meson.build):
 #   Dependencies when using the pangomm library.
-glibmm_req = '>= 2.63.1'
-cairomm_req = '>= 1.15.1'
+
+# Pango supported pkg-config files on MSVC files for a good while,
+# so just use that
 pangocairo_req = '>= 1.41.0'
-glibmm_dep = dependency('glibmm-2.64', version: glibmm_req)
-cairomm_dep = dependency('cairomm-1.16', version: cairomm_req)
 pangocairo_dep = dependency('pangocairo', version: pangocairo_req)
-pangomm_build_dep = [glibmm_dep, cairomm_dep, pangocairo_dep]
-pangomm_requires = ' '.join([
-  'glibmm-2.64', glibmm_req,
-  'cairomm-1.16', cairomm_req,
-  'pangocairo', pangocairo_req,
-])
+
+# The -mm libraries do not yet have pkg-config files for MSVC builds,
+# so check for them manually
+glibmm_req_minor_ver = '64'
+cairomm_req_minor_ver = '16'
+
+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')
+
+  assert(cpp_compiler.has_header('sigc++-3.0/sigc++/sigc++.h') and 
cpp_compiler.has_header('sigc++-3.0/include/sigc++config.h'),
+         'sigc++-3.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))
+  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++-3.x'.format(glibmm_req_minor_ver, cairomm_req_minor_ver))
+
+  # Visual Studio 2019 can consume libraries built with 2017, so check for
+  # 2017-built libraries as well if 2019-built libraries cannot be found
+  msvc_check_range = [15]
+  msvc_minor = cpp_compiler.version().split('.')[1].to_int()
+  if msvc_minor >= 20
+    msvc_check_range = [16, 15]
+  endif
+
+  debugsuffix = ''
+  if get_option('buildtype') == 'debug'
+    debugsuffix = '-d'
+  endif
+
+  # 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
+  glibmm_dep = dependency('', required: false)
+  cairomm_dep = dependency('', required: false)
+  sigc_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)
+    sigc_dep = sigc_dep.found() ? sigc_dep : 
cpp_compiler.find_library('sigc-vc@0@0@1@-3_0'.format(v.to_string(), debugsuffix), required: false)
+  endforeach
+
+  # Now make sure the appropriate -mm libraries are found
+  assert(glibmm_dep.found(), 'Appropriate glibmm-vcxx0@0@-2_@1@.format(debugsuffix, 
glibmm_req_minor_ver).lib is required')
+  assert(cairomm_dep.found(), 'Appropriate cairomm-vcxx0@0@-2_@1@.format(debugsuffix, 
cairomm_req_minor_ver).lib is required')
+  assert(sigc_dep.found(), 'Appropriate sigc-vcxx0@0@-3_0.format(debugsuffix).lib is required')
+
+  pangomm_requires = ' '.join([
+    'pangocairo', pangocairo_req,
+  ])
+
+  pangomm_build_dep = [glibmm_dep, cairomm_dep, sigc_dep, pangocairo_dep]
+else
+  glibmm_req = '>= 2.63.1'
+  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)
+  pangomm_build_dep = [glibmm_dep, cairomm_dep, pangocairo_dep]
+  pangomm_requires = ' '.join([
+    'glibmm-2.@0@'.format(glibmm_req_minor_ver), glibmm_req,
+    'cairomm-1.@0@'.format(cairomm_req_minor_ver), cairomm_req,
+    'pangocairo', pangocairo_req,
+  ])
+endif
 
 # Some dependencies are required only in maintainer mode and/or if
 # reference documentation shall be built.
@@ -112,8 +171,10 @@ doxygen = find_program('doxygen', required: build_documentation)
 dot = find_program('dot', required: build_documentation) # Used by Doxygen
 xsltproc = find_program('xsltproc', required: build_documentation)
 
-# Where to find gmmproc and generate_wrap_init.pl.
-gmmproc_dir = glibmm_dep.get_pkgconfig_variable('gmmprocdir')
+# Where to find gmmproc and generate_wrap_init.pl. (N/A on MSVC builds)
+if not is_msvc
+  gmmproc_dir = glibmm_dep.get_pkgconfig_variable('gmmprocdir')
+endif
 
 script_dir = project_source_root / 'untracked' / 'build_scripts'
 generate_binding = script_dir / 'generate-binding.py'