[GSoC][PATCH v13 02/10] fsck: add a unified interface for reporting fsck messages

[shejialuo <shejialuo@gmail.com>]

The static function "report" provided by "fsck.c" aims at checking fsck
error type and calling the callback "error_func" to report the message.
However, "report" function is only related to object database which
cannot be reused for refs. In order to provide a unified interface which
can report either objects or refs, create a new function "fsck_vreport"
following the "report" prototype. Instead of using "...", provide
"va_list" to allow more flexibility.

In order to provide an extensible error report for refs, add a new
"fsck_refs_info" structure and add parameter "const struct
*fsck_refs_info" into "fsck_vreport" function.

Like "report", the "fsck_vreport" function will use "error_func"
registered in "fsck_options" to report customized messages. Change
"error_func" prototype to align with the new "fsck_vreport".

Then, change "report" function to use "fsck_vreport" to report objects
related messages. Add a new function called "fsck_refs_report" to use
"fsck_vreport" to report refs related messages.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: shejialuo <shejialuo@gmail.com>
---
 builtin/fsck.c  |  1 +
 builtin/mktag.c |  1 +
 fsck.c          | 56 +++++++++++++++++++++++++++++++++++++++++--------
 fsck.h          | 25 +++++++++++++++++++++-
 object-file.c   | 11 +++++-----
 5 files changed, 79 insertions(+), 15 deletions(-)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index d13a226c2e..6abad60e7e 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -92,6 +92,7 @@ static int objerror(struct object *obj, const char *err)
 static int fsck_error_func(struct fsck_options *o UNUSED,
 			   const struct object_id *oid,
 			   enum object_type object_type,
+			   const struct fsck_refs_info *refs_info UNUSED,
 			   enum fsck_msg_type msg_type,
 			   enum fsck_msg_id msg_id UNUSED,
 			   const char *message)
diff --git a/builtin/mktag.c b/builtin/mktag.c
index 4767f1a97e..6496deca0a 100644
--- a/builtin/mktag.c
+++ b/builtin/mktag.c
@@ -20,6 +20,7 @@ static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
 static int mktag_fsck_error_func(struct fsck_options *o UNUSED,
 				 const struct object_id *oid UNUSED,
 				 enum object_type object_type UNUSED,
+				 const struct fsck_refs_info *refs_info UNUSED,
 				 enum fsck_msg_type msg_type,
 				 enum fsck_msg_id msg_id UNUSED,
 				 const char *message)
diff --git a/fsck.c b/fsck.c
index 3f32441492..1185e9a8ad 100644
--- a/fsck.c
+++ b/fsck.c
@@ -226,12 +226,18 @@ static int object_on_skiplist(struct fsck_options *opts,
 	return opts && oid && oidset_contains(&opts->skip_oids, oid);
 }
 
-__attribute__((format (printf, 5, 6)))
-static int report(struct fsck_options *options,
-		  const struct object_id *oid, enum object_type object_type,
-		  enum fsck_msg_id msg_id, const char *fmt, ...)
+/*
+ * Provide a unified interface for either fscking refs or objects.
+ * It will get the current msg error type and call the error_func callback
+ * which is registered in the "fsck_options" struct.
+ */
+static int fsck_vreport(struct fsck_options *options,
+			const struct object_id *oid,
+			enum object_type object_type,
+			const struct fsck_refs_info *refs_info,
+			enum fsck_msg_id msg_id, const char *fmt, va_list ap)
 {
-	va_list ap;
+	va_list ap_copy;
 	struct strbuf sb = STRBUF_INIT;
 	enum fsck_msg_type msg_type = fsck_msg_type(msg_id, options);
 	int result;
@@ -250,9 +256,9 @@ static int report(struct fsck_options *options,
 	prepare_msg_ids();
 	strbuf_addf(&sb, "%s: ", msg_id_info[msg_id].camelcased);
 
-	va_start(ap, fmt);
-	strbuf_vaddf(&sb, fmt, ap);
-	result = options->error_func(options, oid, object_type,
+	va_copy(ap_copy, ap);
+	strbuf_vaddf(&sb, fmt, ap_copy);
+	result = options->error_func(options, oid, object_type, refs_info,
 				     msg_type, msg_id, sb.buf);
 	strbuf_release(&sb);
 	va_end(ap);
@@ -260,6 +266,35 @@ static int report(struct fsck_options *options,
 	return result;
 }
 
+__attribute__((format (printf, 5, 6)))
+static int report(struct fsck_options *options,
+		  const struct object_id *oid, enum object_type object_type,
+		  enum fsck_msg_id msg_id, const char *fmt, ...)
+{
+	va_list ap;
+	int result;
+
+	va_start(ap, fmt);
+	result = fsck_vreport(options, oid, object_type, NULL, msg_id, fmt, ap);
+	va_end(ap);
+
+	return result;
+}
+
+int fsck_refs_report(struct fsck_options *options,
+		     const struct object_id *oid,
+		     const struct fsck_refs_info *refs_info,
+		     enum fsck_msg_id msg_id, const char *fmt, ...)
+{
+	va_list ap;
+	int result;
+	va_start(ap, fmt);
+	result = fsck_vreport(options, oid, OBJ_NONE, refs_info,
+			      msg_id, fmt, ap);
+	va_end(ap);
+	return result;
+}
+
 void fsck_enable_object_names(struct fsck_options *options)
 {
 	if (!options->object_names)
@@ -1203,6 +1238,7 @@ int fsck_buffer(const struct object_id *oid, enum object_type type,
 int fsck_error_function(struct fsck_options *o,
 			const struct object_id *oid,
 			enum object_type object_type UNUSED,
+			const struct fsck_refs_info *refs_info UNUSED,
 			enum fsck_msg_type msg_type,
 			enum fsck_msg_id msg_id UNUSED,
 			const char *message)
@@ -1306,6 +1342,7 @@ int git_fsck_config(const char *var, const char *value,
 int fsck_error_cb_print_missing_gitmodules(struct fsck_options *o,
 					   const struct object_id *oid,
 					   enum object_type object_type,
+					   const struct fsck_refs_info *refs_info,
 					   enum fsck_msg_type msg_type,
 					   enum fsck_msg_id msg_id,
 					   const char *message)
@@ -1314,5 +1351,6 @@ int fsck_error_cb_print_missing_gitmodules(struct fsck_options *o,
 		puts(oid_to_hex(oid));
 		return 0;
 	}
-	return fsck_error_function(o, oid, object_type, msg_type, msg_id, message);
+	return fsck_error_function(o, oid, object_type, refs_info,
+				   msg_type, msg_id, message);
 }
diff --git a/fsck.h b/fsck.h
index bcfb2e34cd..4f01a46cc7 100644
--- a/fsck.h
+++ b/fsck.h
@@ -92,6 +92,7 @@ enum fsck_msg_id {
 };
 #undef MSG_ID
 
+struct fsck_refs_info;
 struct fsck_options;
 struct object;
 
@@ -114,23 +115,35 @@ int is_valid_msg_type(const char *msg_id, const char *msg_type);
 typedef int (*fsck_walk_func)(struct object *obj, enum object_type object_type,
 			      void *data, struct fsck_options *options);
 
-/* callback for fsck_object, type is FSCK_ERROR or FSCK_WARN */
+/*
+ * callback function for reporting errors when checking either objects or refs
+ */
 typedef int (*fsck_error)(struct fsck_options *o,
 			  const struct object_id *oid, enum object_type object_type,
+			  const struct fsck_refs_info *refs_info,
 			  enum fsck_msg_type msg_type, enum fsck_msg_id msg_id,
 			  const char *message);
 
 int fsck_error_function(struct fsck_options *o,
 			const struct object_id *oid, enum object_type object_type,
+			const struct fsck_refs_info *refs_info,
 			enum fsck_msg_type msg_type, enum fsck_msg_id msg_id,
 			const char *message);
 int fsck_error_cb_print_missing_gitmodules(struct fsck_options *o,
 					   const struct object_id *oid,
 					   enum object_type object_type,
+					   const struct fsck_refs_info *refs_info,
 					   enum fsck_msg_type msg_type,
 					   enum fsck_msg_id msg_id,
 					   const char *message);
 
+/*
+ * The information for reporting refs-related error message
+ */
+struct fsck_refs_info {
+	const char *path;
+};
+
 struct fsck_options {
 	fsck_walk_func walk;
 	fsck_error error_func;
@@ -209,6 +222,16 @@ int fsck_tag_standalone(const struct object_id *oid, const char *buffer,
  */
 int fsck_finish(struct fsck_options *options);
 
+/*
+ * Report an error or warning for refs.
+ */
+__attribute__((format (printf, 5, 6)))
+int fsck_refs_report(struct fsck_options *options,
+		     const struct object_id *oid,
+		     const struct fsck_refs_info *refs_info,
+		     enum fsck_msg_id msg_id,
+		     const char *fmt, ...);
+
 /*
  * Subsystem for storing human-readable names for each object.
  *
diff --git a/object-file.c b/object-file.c
index 065103be3e..91ddab2696 100644
--- a/object-file.c
+++ b/object-file.c
@@ -2470,11 +2470,12 @@ int repo_has_object_file(struct repository *r,
  * give more context.
  */
 static int hash_format_check_report(struct fsck_options *opts UNUSED,
-				     const struct object_id *oid UNUSED,
-				     enum object_type object_type UNUSED,
-				     enum fsck_msg_type msg_type UNUSED,
-				     enum fsck_msg_id msg_id UNUSED,
-				     const char *message)
+				    const struct object_id *oid UNUSED,
+				    enum object_type object_type UNUSED,
+				    const struct fsck_refs_info *refs_info UNUSED,
+				    enum fsck_msg_type msg_type UNUSED,
+				    enum fsck_msg_id msg_id UNUSED,
+				    const char *message)
 {
 	error(_("object fails fsck: %s"), message);
 	return 1;
-- 
2.45.2