Introduce a way to show config warnings in swaynag

Adds the function `config_add_swaynag_warning(char *fmt, ...)` so that
handlers can add warnings to the swaynag config log in a uniform way.
The formatting is identical to errors and include the line number, line,
and config path.

This also alters the background file access warning to use the function
and introduces a warning for duplicate bindings.

1 files changed, 7 insertions, 0 deletions

diff --git a/include/sway/config.h b/include/sway/config.h
index 1ff9a104..d02b0d63 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -425,6 +425,8 @@ struct sway_config {
 	list_t *config_chain;
 	const char *current_config_path;
 	const char *current_config;
+	int current_config_line_number;
+	char *current_config_line;
 
 	enum sway_container_border border;
 	enum sway_container_border floating_border;
@@ -490,6 +492,11 @@ bool read_config(FILE *file, struct sway_config *config,
 		struct swaynag_instance *swaynag);
 
 /**
+ * Adds a warning entry to the swaynag instance used for errors.
+ */
+void config_add_swaynag_warning(char *fmt, ...);
+
+/**
  * Free config struct
  */
 void free_config(struct sway_config *config);