meson: Generate the pkg-config file

Instead of using a template file, and filling in the blanks, we can use
the Meson pkgconfig module to generate the pkg-config file mostly from
the library object itself — including dependencies and flags.

The template file remains in tree for the Autotools build.

meson.build

@@ -231,12 +231,6 @@ if dl_dep.found()
   pkgconf.set('DLOPEN_LIBS', '-ldl')
 endif
 
-configure_file(input: 'epoxy.pc.in',
-               output: 'epoxy.pc',
-               configuration: pkgconf,
-               install: true,
-               install_dir: join_paths(epoxy_libdir, 'pkgconfig'))
-
 # Python
 python = import('python3').find_python()
 if not python.found()

src/meson.build

@@ -67,31 +67,38 @@ if host_system == 'windows'
   epoxy_deps += [ opengl32_dep, gdi32_dep ]
 endif
 
-# Allow building a static version of epoxy
+libepoxy = library(
-if libtype != 'shared'
+  'epoxy',
-  libepoxy_static = static_library('epoxy',
-                                   sources: epoxy_sources + epoxy_headers,
-                                   install: true,
-                                   dependencies: epoxy_deps,
-                                   include_directories: libepoxy_inc,
-                                   c_args: common_cflags + visibility_cflags,
-                                   link_args: common_ldflags)
-  libepoxy = libepoxy_static
-endif
-
-if libtype != 'static'
-  libepoxy_shared = shared_library('epoxy',
   sources: epoxy_sources + epoxy_headers,
   version: '0.0.0',
   install: true,
   dependencies: epoxy_deps,
   include_directories: libepoxy_inc,
   c_args: common_cflags + visibility_cflags,
-                                   link_args: common_ldflags)
+  link_args: common_ldflags,
-  libepoxy = libepoxy_shared
+)
-endif
 
-libepoxy_dep = declare_dependency(link_with: libepoxy,
+libepoxy_dep = declare_dependency(
+  link_with: libepoxy,
   include_directories: libepoxy_inc,
   dependencies: epoxy_deps,
-                                  sources: epoxy_headers)
+  sources: epoxy_headers,
+)
+
+epoxy_has_glx = build_glx ? '1' : '0'
+epoxy_has_egl = build_egl ? '1' : '0'
+epoxy_has_wgl = build_wgl ? '1' : '0'
+
+pkg = import('pkgconfig')
+pkg.generate(
+  libraries: libepoxy,
+  name: 'epoxy',
+  description: 'GL dispatch library',
+  version: meson.project_version(),
+  variables: [
+    'epoxy_has_glx=@0@'.format(epoxy_has_glx),
+    'epoxy_has_egl=@0@'.format(epoxy_has_egl),
+    'epoxy_has_wgl=@0@'.format(epoxy_has_wgl),
+  ],
+  filebase: 'epoxy',
+)