odb: convert object info flags into an enum

Convert the object info flags into an enum and adapt all functions that
receive these flags as parameters to use the enum instead of an integer.
This serves two purposes:

  - The function signatures become more self-documenting, as callers
    don't have to wonder which flags they expect.

  - The compiler can warn when a wrong flag type is passed.

Note that the second benefit is somewhat limited. For example, when
or-ing multiple enum flags together the result will be an integer, and
the compiler will not warn about such use cases. But where it does help
is when a single flag of the wrong type is passed, as the compiler would
generate a warning in that case.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 23 insertions, 17 deletions

diff --git a/odb.h b/odb.h
index 8e1fca7755..e94cdc3665 100644
--- a/odb.h
+++ b/odb.h
@@ -352,23 +352,29 @@ struct object_info {
  */
 #define OBJECT_INFO_INIT { 0 }
 
-/* Invoke lookup_replace_object() on the given hash */
-#define OBJECT_INFO_LOOKUP_REPLACE (1 << 0)
-/* Do not retry packed storage after checking packed and loose storage */
-#define OBJECT_INFO_QUICK (1 << 1)
-/*
- * Do not attempt to fetch the object if missing (even if fetch_is_missing is
- * nonzero).
- */
-#define OBJECT_INFO_SKIP_FETCH_OBJECT (1 << 2)
-/*
- * This is meant for bulk prefetching of missing blobs in a partial
- * clone. Implies OBJECT_INFO_SKIP_FETCH_OBJECT and OBJECT_INFO_QUICK
- */
-#define OBJECT_INFO_FOR_PREFETCH (OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK)
+/* Flags that can be passed to `odb_read_object_info_extended()`. */
+enum object_info_flags {
+	/* Invoke lookup_replace_object() on the given hash. */
+	OBJECT_INFO_LOOKUP_REPLACE = (1 << 0),
+
+	/* Do not reprepare object sources when the first lookup has failed. */
+	OBJECT_INFO_QUICK = (1 << 1),
+
+	/*
+	 * Do not attempt to fetch the object if missing (even if fetch_is_missing is
+	 * nonzero).
+	 */
+	OBJECT_INFO_SKIP_FETCH_OBJECT = (1 << 2),
+
+	/* Die if object corruption (not just an object being missing) was detected. */
+	OBJECT_INFO_DIE_IF_CORRUPT = (1 << 3),
 
-/* Die if object corruption (not just an object being missing) was detected. */
-#define OBJECT_INFO_DIE_IF_CORRUPT (1 << 3)
+	/*
+	 * This is meant for bulk prefetching of missing blobs in a partial
+	 * clone. Implies OBJECT_INFO_SKIP_FETCH_OBJECT and OBJECT_INFO_QUICK.
+	 */
+	OBJECT_INFO_FOR_PREFETCH = (OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK),
+};
 
 /*
  * Read object info from the object database and populate the `object_info`
@@ -377,7 +383,7 @@ struct object_info {
 int odb_read_object_info_extended(struct object_database *odb,
 				  const struct object_id *oid,
 				  struct object_info *oi,
-				  unsigned flags);
+				  enum object_info_flags flags);
 
 /*
  * Read a subset of object info for the given object ID. Returns an `enum