weston-log: Start adding documentation for the logging/debugging framework

Adds initial grouping for sphinx/breathe for the logging/debugging
framework. We add a few groups: log (public API), internal-log (private API,
not exported) and debug-protocol, specific to the weston
debug protocol.

In latest version of breathe, '\memberof' command is recognized as such.
But it conflicts with '\ingroup' command and can't be used in the same
time (leading to duplicate symbols), so we follow a simple rule: object
tagging with '\ingroup' then use '\memberof' command for the functions
that work on that object.

There's also a caveat here: we have objects that are private (opaque)
but the functions are public. For those cases we resort to using
'internal-log' for the object (class) and 'log' for the functions.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>

libweston/weston-log-internal.h

@@ -46,7 +46,7 @@ struct weston_log_subscription;
  * Passing the base class will require container retrieval type of methods
  * to be allowed to reach the opaque type (i.e., container_of()).
  *
- * @internal
+ * @ingroup internal-log
  *
  */
 struct weston_log_subscriber {

libweston/weston-log.c

@@ -40,6 +40,12 @@
 #include <errno.h>
 #include <sys/time.h>
 
+/**
+ * @defgroup log Public Logging/Debugging API
+ * @defgroup internal-log Private/Internal Logging/Debugging API
+ * @defgroup debug-protocol weston-debug protocol specific
+ */
+
 /** Main weston-log context
  *
  * One per weston_compositor. Stores list of scopes created and a list pending
@@ -56,7 +62,7 @@
  * connects and subscribes to a scope which was previously advertised by the
  * compositor.
  *
- * @internal
+ * @ingroup internal-log
  */
 struct weston_log_context {
 	struct wl_global *global;
@@ -69,6 +75,8 @@ struct weston_log_context {
  * This is used for scoping logging/debugging messages. Clients can subscribe
  * to only the scopes they are interested in. A scope is identified by its name
  * (also referred to as debug stream name).
+ *
+ * @ingroup log
  */
 struct weston_log_scope {
 	char *name;
@@ -94,7 +102,7 @@ struct weston_log_scope {
  * A subscription can reached from a subscriber subscription list by using the
  * streams base class.
  *
- * @internal
+ * @ingroup internal-log
  */
 struct weston_log_subscription {
 	struct weston_log_subscriber *owner;
@@ -163,6 +171,10 @@ weston_log_subscription_destroy_pending(struct weston_log_subscription *sub)
 	free(sub);
 }
 
+/** Write to the stream's subscription
+ *
+ * @memberof weston_log_subscription
+ */
 static void
 weston_log_subscription_write(struct weston_log_subscription *sub,
 			      const char *data, size_t len)
@@ -171,6 +183,10 @@ weston_log_subscription_write(struct weston_log_subscription *sub,
 		sub->owner->write(sub->owner, data, len);
 }
 
+/** Write a formatted string to the stream's subscription
+ *
+ * @memberof weston_log_subscription
+ */
 static void
 weston_log_subscription_vprintf(struct weston_log_subscription *sub,
 				const char *fmt, va_list ap)
@@ -207,9 +223,9 @@ weston_log_subscription_vprintf(struct weston_log_subscription *sub,
  * @returns a weston_log_subscription object in case of success, or NULL
  * otherwise
  *
- * @internal
  * @sa weston_log_subscription_destroy, weston_log_subscription_remove,
  * weston_log_subscription_add
+ * @memberof weston_log_subscription
  */
 void
 weston_log_subscription_create(struct weston_log_subscriber *owner,
@@ -260,7 +276,7 @@ weston_log_subscription_destroy(struct weston_log_subscription *sub)
  * @param subscriber the subscriber in question
  * @returns a weston_log_subscription object
  *
- * @internal
+ * @memberof weston_log_subscription
  */
 struct weston_log_subscription *
 weston_log_subscriber_get_only_subscription(struct weston_log_subscriber *subscriber)
@@ -286,7 +302,7 @@ weston_log_subscriber_get_only_subscription(struct weston_log_subscriber *subscr
  * @param sub the subscription, it must be created before, see
  * weston_log_subscription_create()
  *
- * @internal
+ * @memberof weston_log_subscription
  */
 void
 weston_log_subscription_add(struct weston_log_scope *scope,
@@ -303,7 +319,7 @@ weston_log_subscription_add(struct weston_log_scope *scope,
 
 /** Removes the subscription from the scope's subscription list
  *
- * @internal
+ * @memberof weston_log_subscription
  */
 void
 weston_log_subscription_remove(struct weston_log_subscription *sub)
@@ -321,7 +337,7 @@ weston_log_subscription_remove(struct weston_log_subscription *sub)
  * @param name the scope name, see weston_compositor_add_log_scope()
  * @returns NULL if none found, or a pointer to a weston_log_scope
  *
- * @internal
+ * @ingroup internal-log
  */
 struct weston_log_scope *
 weston_log_get_scope(struct weston_log_context *log_ctx, const char *name)
@@ -336,7 +352,7 @@ weston_log_get_scope(struct weston_log_context *log_ctx, const char *name)
 /** Wrapper to invoke the weston_log_scope_cb. Allows to call the cb new_subscriber of
  * a log scope.
  *
- * @internal
+ * @ingroup internal-log
  */
 void
 weston_log_run_cb_new_subscriber(struct weston_log_subscription *sub)
@@ -349,7 +365,7 @@ weston_log_run_cb_new_subscriber(struct weston_log_subscription *sub)
  *
  * This is only used by the weston-debug protocol!
  *
- * @internal
+ * @ingroup internal-log
  */
 void
 weston_debug_protocol_advertise_scopes(struct weston_log_context *log_ctx,
@@ -368,6 +384,8 @@ weston_debug_protocol_advertise_scopes(struct weston_log_context *log_ctx,
  * \return 0 on success, -1 on failure
  *
  * Sets weston_compositor::weston_log_ctx.
+ *
+ * @ingroup log
  */
 int
 weston_log_ctx_compositor_setup(struct weston_compositor *compositor,
@@ -386,6 +404,7 @@ weston_log_ctx_compositor_setup(struct weston_compositor *compositor,
  * success
  *
  * weston_log_context is a singleton for each weston_compositor.
+ * @ingroup log
  *
  */
 WL_EXPORT struct weston_log_context *
@@ -408,6 +427,7 @@ weston_log_ctx_compositor_create(void)
  * \param compositor The libweston compositor whose weston-debug to tear down.
  *
  * Clears weston_compositor::weston_log_ctx.
+ * @ingroup log
  *
  */
 WL_EXPORT void
@@ -456,6 +476,8 @@ weston_log_ctx_compositor_destroy(struct weston_compositor *compositor)
  *
  * The debug extension is disabled by default, and once enabled, cannot be
  * disabled again.
+ *
+ * @ingroup debug-protocol
  */
 WL_EXPORT void
 weston_compositor_enable_debug_protocol(struct weston_compositor *compositor)
@@ -478,7 +500,10 @@ weston_compositor_enable_debug_protocol(struct weston_compositor *compositor)
 
 /** Determine if the debug protocol has been enabled
  *
- * \param wc The libweston compositor to verify if debug protocol has been enabled
+ * \param wc The libweston compositor to verify if debug protocol has been
+ * enabled
+ *
+ * @ingroup debug-protocol
  */
 WL_EXPORT bool
 weston_compositor_is_debug_protocol_enabled(struct weston_compositor *wc)
@@ -657,6 +682,7 @@ weston_log_scope_is_enabled(struct weston_log_scope *scope)
 
 /** Close the stream's complete callback if one was installed/created.
  *
+ * @ingroup log
  */
 WL_EXPORT void
 weston_log_subscription_complete(struct weston_log_subscription *sub)
@@ -779,6 +805,7 @@ weston_log_scope_printf(struct weston_log_scope *scope,
  *
  * Writes to formatted string to the stream that created the subscription.
  *
+ * @ingroup log
  */
 WL_EXPORT void
 weston_log_subscription_printf(struct weston_log_subscription *sub,
@@ -801,6 +828,8 @@ weston_log_subscription_printf(struct weston_log_subscription *sub,
  * Reads the current local wall-clock time and formats it into a string.
  * and append the debug scope name to it, if a scope is available.
  * The string is NUL-terminated, even if truncated.
+ *
+ * @memberof weston_log_scope
  */
 WL_EXPORT char *
 weston_log_scope_timestamp(struct weston_log_scope *scope,
@@ -844,6 +873,8 @@ weston_log_scope_timestamp(struct weston_log_scope *scope,
  * @param subscriber the subscriber, which has to be created before
  * @param scope_name the scope name. In case the scope is not created
  * we temporarily store the subscription in the pending list.
+ *
+ * @ingroup log
  */
 WL_EXPORT void
 weston_log_subscribe(struct weston_log_context *log_ctx,