doc: store path to dynamic library in plugin configuration

This can then be used by the pre-commit hook to avoid rebuilding
complete plugin caches to check a change, thus minimizing the potential
diff and making analysis of completely-unrelated cache diffs much less
likely.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8231>

subprojects/gstreamer/docs/gst-plugins-doc-cache-generator.py

@@ -48,6 +48,7 @@ class GstPluginsHotdocConfGen:
         parser.add_argument('--include_paths', nargs='*', default=[])
         parser.add_argument('--gst_c_source_filters', nargs='*', default=[])
         parser.add_argument('--gst_c_source_file', type=P)
+        parser.add_argument('--gst_plugin_libraries_file', type=P)
         parser.add_argument('--output', type=P)
 
         parser.parse_args(namespace=self, args=sys.argv[2:])
@@ -61,6 +62,12 @@ class GstPluginsHotdocConfGen:
         else:
             gst_c_source_map = {}
 
+        if self.gst_plugin_libraries_file is not None:
+            with self.gst_plugin_libraries_file.open() as fd:
+                gst_plugin_libraries_map = json.load(fd)
+        else:
+            gst_plugin_libraries_map = {}
+
         with self.gst_cache_file.open() as fd:
             all_plugins = json.load(fd)
 
@@ -91,6 +98,7 @@ class GstPluginsHotdocConfGen:
                         'gst_c_source_filters': [str(s) for s in self.gst_c_source_filters],
                         'include_paths': self.include_paths,
                         'gst_order_generated_subpages': True,
+                        'gst_plugin_library': gst_plugin_libraries_map.get(plugin_name),
                     }, f, indent=4)
 
         if self.output is not None:

subprojects/gstreamer/docs/meson.build

@@ -168,6 +168,22 @@ cdir = meson.current_source_dir()
 
 doc_source_file = configure_file(output: 'doc_sources.json', configuration: plugin_sources, output_format: 'json')
 
+plugin_libraries = {}
+
+foreach plugin: plugins
+  if plugin.name().startswith('gst')
+    plugin_name = plugin.name().substring(3)
+  else
+    plugin_name = plugin.name()
+  endif
+
+  plugin_libraries += {
+    plugin_name: plugin.full_path()
+  }
+endforeach
+
+doc_plugin_libs_file = configure_file(output: 'doc_plugin_libs.json', configuration: plugin_libraries, output_format: 'json')
+
 plugin_hotdoc_configs = custom_target(
   'build-hotdoc-configs',
   command: [
@@ -179,6 +195,7 @@ plugin_hotdoc_configs = custom_target(
     '--index', cdir / 'plugins/index.md',
     '--gst_index', cdir / 'plugins/index.md',
     '--gst_c_source_file', doc_source_file,
+    '--gst_plugin_libraries_file', doc_plugin_libs_file,
     '--gst_c_sources',
       cdir / '../plugins/*/*.c',
       cdir / '../plugins/*/*.h',