fsck.h: move FSCK_{FATAL,INFO,ERROR,WARN,IGNORE} into an enum

Move the FSCK_{FATAL,INFO,ERROR,WARN,IGNORE} defines into a new
fsck_msg_type enum.

These defines were originally introduced in:

 - ba002f3b28 (builtin-fsck: move common object checking code to
   fsck.c, 2008-02-25)
 - f50c440730 (fsck: disallow demoting grave fsck errors to warnings,
   2015-06-22)
 - efaba7cc77 (fsck: optionally ignore specific fsck issues
   completely, 2015-06-22)
 - f27d05b170 (fsck: allow upgrading fsck warnings to errors,
   2015-06-22)

The reason these were defined in two different places is because we
use FSCK_{IGNORE,INFO,FATAL} only in fsck.c, but FSCK_{ERROR,WARN} are
used by external callbacks.

Untangling that would take some more work, since we expose the new
"enum fsck_msg_type" to both. Similar to "enum object_type" it's not
worth structuring the API in such a way that only those who need
FSCK_{ERROR,WARN} pass around a different type.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fsck.c

@@ -84,7 +84,7 @@ static int objerror(struct object *obj, const char *err)
 static int fsck_error_func(struct fsck_options *o,
 			   const struct object_id *oid,
 			   enum object_type object_type,
-			   int msg_type, const char *message)
+			   enum fsck_msg_type msg_type, const char *message)
 {
 	switch (msg_type) {
 	case FSCK_WARN:

builtin/index-pack.c

@@ -1716,7 +1716,8 @@ static void show_pack_info(int stat_only)
 static int print_dangling_gitmodules(struct fsck_options *o,
 				     const struct object_id *oid,
 				     enum object_type object_type,
-				     int msg_type, const char *message)
+				     enum fsck_msg_type msg_type,
+				     const char *message)
 {
 	/*
 	 * NEEDSWORK: Plumb the MSG_ID (from fsck.c) here and use it

builtin/mktag.c

@@ -17,7 +17,8 @@ static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
 static int mktag_fsck_error_func(struct fsck_options *o,
 				 const struct object_id *oid,
 				 enum object_type object_type,
-				 int msg_type, const char *message)
+				 enum fsck_msg_type msg_type,
+				 const char *message)
 {
 	switch (msg_type) {
 	case FSCK_WARN:

fsck.c

@@ -22,9 +22,6 @@
 static struct oidset gitmodules_found = OIDSET_INIT;
 static struct oidset gitmodules_done = OIDSET_INIT;
 
-#define FSCK_FATAL -1
-#define FSCK_INFO -2
-
 #define FOREACH_MSG_ID(FUNC) \
 	/* fatal errors */ \
 	FUNC(NUL_IN_HEADER, FATAL) \
@@ -97,7 +94,7 @@ static struct {
 	const char *id_string;
 	const char *downcased;
 	const char *camelcased;
-	int msg_type;
+	enum fsck_msg_type msg_type;
 } msg_id_info[FSCK_MSG_MAX + 1] = {
 	FOREACH_MSG_ID(MSG_ID)
 	{ NULL, NULL, NULL, -1 }
@@ -164,13 +161,13 @@ void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
 		list_config_item(list, prefix, msg_id_info[i].camelcased);
 }
 
-static int fsck_msg_type(enum fsck_msg_id msg_id,
+static enum fsck_msg_type fsck_msg_type(enum fsck_msg_id msg_id,
 	struct fsck_options *options)
 {
 	assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 
 	if (!options->msg_type) {
-		int msg_type = msg_id_info[msg_id].msg_type;
+		enum fsck_msg_type msg_type = msg_id_info[msg_id].msg_type;
 
 		if (options->strict && msg_type == FSCK_WARN)
 			msg_type = FSCK_ERROR;
@@ -180,7 +177,7 @@ static int fsck_msg_type(enum fsck_msg_id msg_id,
 	return options->msg_type[msg_id];
 }
 
-static int parse_msg_type(const char *str)
+static enum fsck_msg_type parse_msg_type(const char *str)
 {
 	if (!strcmp(str, "error"))
 		return FSCK_ERROR;
@@ -203,7 +200,8 @@ int is_valid_msg_type(const char *msg_id, const char *msg_type)
 void fsck_set_msg_type(struct fsck_options *options,
 		       const char *msg_id_str, const char *msg_type_str)
 {
-	int msg_id = parse_msg_id(msg_id_str), msg_type;
+	int msg_id = parse_msg_id(msg_id_str);
+	enum fsck_msg_type msg_type;
 
 	if (msg_id < 0)
 		die("Unhandled message id: %s", msg_id_str);
@@ -214,7 +212,7 @@ void fsck_set_msg_type(struct fsck_options *options,
 
 	if (!options->msg_type) {
 		int i;
-		int *severity;
+		enum fsck_msg_type *severity;
 		ALLOC_ARRAY(severity, FSCK_MSG_MAX);
 		for (i = 0; i < FSCK_MSG_MAX; i++)
 			severity[i] = fsck_msg_type(i, options);
@@ -275,7 +273,8 @@ static int report(struct fsck_options *options,
 {
 	va_list ap;
 	struct strbuf sb = STRBUF_INIT;
-	int msg_type = fsck_msg_type(msg_id, options), result;
+	enum fsck_msg_type msg_type = fsck_msg_type(msg_id, options);
+	int result;
 
 	if (msg_type == FSCK_IGNORE)
 		return 0;
@@ -1247,7 +1246,7 @@ int fsck_object(struct object *obj, void *data, unsigned long size,
 int fsck_error_function(struct fsck_options *o,
 			const struct object_id *oid,
 			enum object_type object_type,
-			int msg_type, const char *message)
+			enum fsck_msg_type msg_type, const char *message)
 {
 	if (msg_type == FSCK_WARN) {
 		warning("object %s: %s", fsck_describe_object(o, oid), message);

fsck.h

@@ -3,9 +3,13 @@
 
 #include "oidset.h"
 
-#define FSCK_ERROR 1
-#define FSCK_WARN 2
-#define FSCK_IGNORE 3
+enum fsck_msg_type {
+	FSCK_INFO  = -2,
+	FSCK_FATAL = -1,
+	FSCK_ERROR = 1,
+	FSCK_WARN,
+	FSCK_IGNORE
+};
 
 struct fsck_options;
 struct object;
@@ -29,17 +33,17 @@ typedef int (*fsck_walk_func)(struct object *obj, enum object_type object_type,
 /* callback for fsck_object, type is FSCK_ERROR or FSCK_WARN */
 typedef int (*fsck_error)(struct fsck_options *o,
 			  const struct object_id *oid, enum object_type object_type,
-			  int msg_type, const char *message);
+			  enum fsck_msg_type msg_type, const char *message);
 
 int fsck_error_function(struct fsck_options *o,
 			const struct object_id *oid, enum object_type object_type,
-			int msg_type, const char *message);
+			enum fsck_msg_type msg_type, const char *message);
 
 struct fsck_options {
 	fsck_walk_func walk;
 	fsck_error error_func;
 	unsigned strict:1;
-	int *msg_type;
+	enum fsck_msg_type *msg_type;
 	struct oidset skiplist;
 	kh_oid_map_t *object_names;
 };