merge(3p/git): Merge git upstream at v2.26.2

third_party/git/revision.h

@@ -9,6 +9,19 @@
 #include "diff.h"
 #include "commit-slab-decl.h"
 
+/**
+ * The revision walking API offers functions to build a list of revisions
+ * and then iterate over that list.
+ *
+ * Calling sequence
+ * ----------------
+ *
+ * The walking API has a given calling sequence: first you need to initialize
+ * a rev_info structure, then add revisions to control what kind of revision
+ * list do you want to get, finally you can iterate over the revision list.
+ *
+ */
+
 /* Remember to update object flag allocation in object.h */
 #define SEEN		(1u<<0)
 #define UNINTERESTING   (1u<<1)
@@ -177,10 +190,10 @@ struct rev_info {
 			always_show_header:1;
 
 	/* Format info */
+	int		show_notes;
 	unsigned int	shown_one:1,
 			shown_dashes:1,
 			show_merge:1,
-			show_notes:1,
 			show_notes_given:1,
 			show_signature:1,
 			pretty_given:1,
@@ -306,11 +319,29 @@ struct setup_revision_opt {
 #ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
 #define init_revisions(revs, prefix) repo_init_revisions(the_repository, revs, prefix)
 #endif
+
+/**
+ * Initialize a rev_info structure with default values. The third parameter may
+ * be NULL or can be prefix path, and then the `.prefix` variable will be set
+ * to it. This is typically the first function you want to call when you want
+ * to deal with a revision list. After calling this function, you are free to
+ * customize options, like set `.ignore_merges` to 0 if you don't want to
+ * ignore merges, and so on.
+ */
 void repo_init_revisions(struct repository *r,
 			 struct rev_info *revs,
 			 const char *prefix);
+
+/**
+ * Parse revision information, filling in the `rev_info` structure, and
+ * removing the used arguments from the argument list. Returns the number
+ * of arguments left that weren't recognized, which are also moved to the
+ * head of the argument list. The last parameter is used in case no
+ * parameter given by the first two arguments.
+ */
 int setup_revisions(int argc, const char **argv, struct rev_info *revs,
 		    struct setup_revision_opt *);
+
 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
 			const struct option *options,
 			const char * const usagestr[]);
@@ -319,11 +350,28 @@ void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
 int handle_revision_arg(const char *arg, struct rev_info *revs,
 			int flags, unsigned revarg_opt);
 
+/**
+ * Reset the flags used by the revision walking api. You can use this to do
+ * multiple sequential revision walks.
+ */
 void reset_revision_walk(void);
+
+/**
+ * Prepares the rev_info structure for a walk. You should check if it returns
+ * any error (non-zero return code) and if it does not, you can start using
+ * get_revision() to do the iteration.
+ */
 int prepare_revision_walk(struct rev_info *revs);
+
+/**
+ * Takes a pointer to a `rev_info` structure and iterates over it, returning a
+ * `struct commit *` each time you call it. The end of the revision list is
+ * indicated by returning a NULL pointer.
+ */
 struct commit *get_revision(struct rev_info *revs);
-char *get_revision_mark(const struct rev_info *revs,
-			const struct commit *commit);
+
+const char *get_revision_mark(const struct rev_info *revs,
+			      const struct commit *commit);
 void put_revision_mark(const struct rev_info *revs,
 		       const struct commit *commit);
 
@@ -333,8 +381,19 @@ void mark_trees_uninteresting_sparse(struct repository *r, struct oidset *trees)
 
 void show_object_with_name(FILE *, struct object *, const char *);
 
+/**
+ * This function can be used if you want to add commit objects as revision
+ * information. You can use the `UNINTERESTING` object flag to indicate if
+ * you want to include or exclude the given commit (and commits reachable
+ * from the given commit) from the revision list.
+ *
+ * NOTE: If you have the commits as a string list then you probably want to
+ * use setup_revisions(), instead of parsing each string and using this
+ * function.
+ */
 void add_pending_object(struct rev_info *revs,
 			struct object *obj, const char *name);
+
 void add_pending_oid(struct rev_info *revs,
 		     const char *name, const struct object_id *oid,
 		     unsigned int flags);