Simplify the code generation rules for Meson

The code generation rules are explicitly built for each supported API
target, but they ought to be refactored since they are pretty much
identical.

In order to do that, we can store the arguments to the custom_target
rules inside an array and then iterate over each element.

This cuts down the complexity of the Meson build, and the chances of
getting something wrong due to duplication.

1 files changed, 35 insertions, 67 deletions

diff --git a/src/meson.build b/src/meson.build
index fced355..3610af3 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -1,83 +1,51 @@
-common_sources = [
-  'dispatch_common.c',
-  'dispatch_common.h',
-]
-
 # Configuration file
 configure_file(output: 'config.h', configuration: conf)
 
-gl_generated = custom_target('gl_generated_dispatch.c',
-                             input: gl_registry,
-                             output: [
-                               'gl_generated_dispatch.c',
-                             ],
-                             command: [
-                               python,
-                               gen_dispatch_py,
-                               '--source',
-                               '--no-header',
-                               '--outputdir=@OUTDIR@',
-                               '@INPUT@',
-                             ])
-
-gen_sources = [ gl_generated ]
-sources = common_sources 
+# List of generated sources:
+#   - name of the generated file
+#   - registry source file
+#   - additional sources
+generated_sources = [
+  [ 'gl_generated_dispatch.c', gl_registry, [ 'dispatch_common.c', 'dispatch_common.h' ] ]
+]
 
 if build_egl
-  egl_generated = custom_target('egl_generated_dispatch.c',
-                                input: egl_registry,
-                                output: [
-                                  'egl_generated_dispatch.c',
-                                ],
-                                command: [
-                                  python,
-                                  gen_dispatch_py,
-                                  '--source',
-                                  '--no-header',
-                                  '--outputdir=@OUTDIR@',
-                                  '@INPUT@',
-                                ])
-  gen_sources += [ egl_generated ]                              
-  sources += [ 'dispatch_egl.c' ]
+  generated_sources += [ [ 'egl_generated_dispatch.c', egl_registry, 'dispatch_egl.c' ] ]
 endif
 
 if build_glx
-  glx_generated = custom_target('glx_generated_dispatch.c',
-                                input: glx_registry,
-                                output: [
-                                  'glx_generated_dispatch.c',
-                                ],
-                                command: [
-                                  python,
-                                  gen_dispatch_py,
-                                  '--source',
-                                  '--no-header',
-                                  '--outputdir=@OUTDIR@',
-                                  '@INPUT@',
-                                ])
-  gen_sources += [ glx_generated ]
-  sources += [ 'dispatch_glx.c' ]
+  generated_sources += [ [ 'glx_generated_dispatch.c', glx_registry, 'dispatch_glx.c' ] ]
 endif
 
 if build_wgl
-  wgl_generated = custom_target('wgl_generated_dispatch.c',
-                                input: wgl_registry,
-                                output: [
-                                  'wgl_generated_dispatch.c',
-                                ],
-                                command: [
-                                  python,
-                                  gen_dispatch_py,
-                                  '--source',
-                                  '--no-header',
-                                  '--outputdir=@OUTDIR@',
-                                  '@INPUT@',
-                                ])
-  gen_sources += [ wgl_generated ]
-  sources += [ 'dispatch_wgl.c' ]
+  generated_sources += [ [ 'wgl_generated_dispatch.c', wgl_registry, 'dispatch_wgl.c' ] ]
 endif
 
-epoxy_sources = common_sources + sources + gen_sources
+gen_sources = [ ]
+sources = [ ]
+
+foreach g: generated_sources
+  gen_source = g[0]
+  registry = g[1]
+  source = g[2]
+
+  generated = custom_target(gen_source,
+                            input: registry,
+                            output: [ gen_source ],
+                            command: [
+                              python,
+                              gen_dispatch_py,
+                              '--source',
+                              '--no-header',
+                              '--outputdir=@OUTDIR@',
+                              '@INPUT@',
+                            ])
+
+  gen_sources += [ generated ]
+  sources += [ source ]
+endforeach
+
+epoxy_sources = sources + gen_sources
 epoxy_headers = gen_headers
 foreach h: headers
   epoxy_headers += join_paths(meson.source_root(), 'include/epoxy/@0@'.format(h))