date API: create a date.h, split from cache.h

Move the declaration of the date.c functions from cache.h, and adjust
the relevant users to include the new date.h header.

The show_ident_date() function belonged in pretty.h (it's defined in
pretty.c), its two users outside of pretty.c didn't strictly need to
include pretty.h, as they get it indirectly, but let's add it to them
anyway.

Similarly, the change to "builtin/{fast-import,show-branch,tag}.c"
isn't needed as far as the compiler is concerned, but since they all
use the "DATE_MODE()" macro we now define in date.h, let's have them
include it.

We could simply include this new header in "cache.h", but as this
change shows these functions weren't common enough to warrant
including in it in the first place. By moving them out of cache.h
changes to this API will no longer cause a (mostly) full re-build of
the project when "make" is run.

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

1 files changed, 10 insertions, 0 deletions

diff --git a/pretty.h b/pretty.h
index 2f16acd213..f34e24c53a 100644
--- a/pretty.h
+++ b/pretty.h
@@ -2,6 +2,7 @@
 #define PRETTY_H
 
 #include "cache.h"
+#include "date.h"
 #include "string-list.h"
 
 struct commit;
@@ -163,4 +164,13 @@ int format_set_trailers_options(struct process_trailer_options *opts,
 			const char **arg,
 			char **invalid_arg);
 
+/*
+ * Like show_date, but pull the timestamp and tz parameters from
+ * the ident_split. It will also sanity-check the values and produce
+ * a well-known sentinel date if they appear bogus.
+ */
+const char *show_ident_date(const struct ident_split *id,
+			    const struct date_mode *mode);
+
+
 #endif /* PRETTY_H */