cogl/pipeline: Add API to name a pipeline

It uses static strings, and is meant to make it easier to match what
pipeline source code one might be looking at when running with
COGL_DEBUG=show-sources.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3433>

cogl/cogl/cogl-pipeline-private.h

@@ -368,6 +368,9 @@ struct _CoglPipeline
    * string with a pipeline which can be an aid when trying to trace
    * where the pipeline originates from */
   const char      *static_breadcrumb;
+
+  /* Pointer to a static string with a descriptive name, or NULL. */
+  const char *name;
 };
 
 struct _CoglPipelineClass

cogl/cogl/cogl-pipeline.c

@@ -335,6 +335,8 @@ _cogl_pipeline_copy (CoglPipeline *src, gboolean is_weak)
   if (src->capabilities)
     pipeline->capabilities = g_array_copy (src->capabilities);
 
+  pipeline->name = src->name;
+
   /* XXX:
    * consider generalizing the idea of "cached" properties. These
    * would still have an authority like other sparse properties but
@@ -2855,3 +2857,16 @@ cogl_pipeline_has_capability (CoglPipeline *pipeline,
 
   return FALSE;
 }
+
+void
+cogl_pipeline_set_static_name (CoglPipeline *pipeline,
+                               const char   *name)
+{
+  pipeline->name = name;
+}
+
+const char *
+cogl_pipeline_get_name (CoglPipeline *pipeline)
+{
+  return pipeline->name;
+}

cogl/cogl/cogl-pipeline.h

@@ -160,4 +160,25 @@ cogl_pipeline_has_capability (CoglPipeline *pipeline,
                               GQuark        domain,
                               unsigned int  capability);
 
+/**
+ * cogl_pipeline_set_static_name:
+ * @pipeline: A #CoglPipeline object
+ * @name: A descriptive name
+ *
+ * Set a pipeline name. It may be used for debugging or logging purposes. The
+ * string must be a static string, and string. It will not be copied.
+ */
+COGL_EXPORT void
+cogl_pipeline_set_static_name  (CoglPipeline *pipeline,
+                                const char   *name);
+
+/**
+ * cogl_pipeline_get_name:
+ * @pipeline: A #CoglPipeline object
+ *
+ * Returns: (transfer none): The pipeline name, or %NULL
+ */
+COGL_EXPORT const char *
+cogl_pipeline_get_name (CoglPipeline *pipeline);
+
 G_END_DECLS