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>

18 files changed, 68 insertions, 48 deletions

diff --git a/archive-zip.c b/archive-zip.c
index 2961e01c75..8ea9d1a5da 100644
--- a/archive-zip.c
+++ b/archive-zip.c
@@ -9,6 +9,7 @@
 #include "object-store.h"
 #include "userdiff.h"
 #include "xdiff-interface.h"
+#include "date.h"
 
 static int zip_date;
 static int zip_time;
diff --git a/builtin/am.c b/builtin/am.c
index 7de2c89ef2..eb24bc89bb 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -34,6 +34,7 @@
 #include "string-list.h"
 #include "packfile.h"
 #include "repository.h"
+#include "pretty.h"
 
 /**
  * Returns the length of the first line of msg.
diff --git a/builtin/commit.c b/builtin/commit.c
index b9ed0374e3..6b99ac276d 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -37,6 +37,7 @@
 #include "help.h"
 #include "commit-reach.h"
 #include "commit-graph.h"
+#include "pretty.h"
 
 static const char * const builtin_commit_usage[] = {
 	N_("git commit [<options>] [--] <pathspec>..."),
diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 2b2e28bad7..28f2b9cc91 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -19,6 +19,7 @@
 #include "mem-pool.h"
 #include "commit-reach.h"
 #include "khash.h"
+#include "date.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index e12c5e80e3..330b0553b9 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -8,6 +8,7 @@
 #include "parse-options.h"
 #include "dir.h"
 #include "commit-slab.h"
+#include "date.h"
 
 static const char* show_branch_usage[] = {
     N_("git show-branch [-a | --all] [-r | --remotes] [--topo-order | --date-order]\n"
diff --git a/builtin/tag.c b/builtin/tag.c
index 134b3f1edf..2479da0704 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -20,6 +20,7 @@
 #include "oid-array.h"
 #include "column.h"
 #include "ref-filter.h"
+#include "date.h"
 
 static const char * const git_tag_usage[] = {
 	N_("git tag [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>]\n"
diff --git a/cache.h b/cache.h
index 703a474e5a..48e77aa069 100644
--- a/cache.h
+++ b/cache.h
@@ -1559,46 +1559,6 @@ struct object *repo_peel_to_type(struct repository *r,
 #define peel_to_type(name, namelen, obj, type) \
 	repo_peel_to_type(the_repository, name, namelen, obj, type)
 
-enum date_mode_type {
-	DATE_NORMAL = 0,
-	DATE_HUMAN,
-	DATE_RELATIVE,
-	DATE_SHORT,
-	DATE_ISO8601,
-	DATE_ISO8601_STRICT,
-	DATE_RFC2822,
-	DATE_STRFTIME,
-	DATE_RAW,
-	DATE_UNIX
-};
-
-struct date_mode {
-	enum date_mode_type type;
-	const char *strftime_fmt;
-	int local;
-};
-
-/*
- * Convenience helper for passing a constant type, like:
- *
- *   show_date(t, tz, DATE_MODE(NORMAL));
- */
-#define DATE_MODE(t) date_mode_from_type(DATE_##t)
-struct date_mode *date_mode_from_type(enum date_mode_type type);
-
-const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
-void show_date_relative(timestamp_t time, struct strbuf *timebuf);
-int parse_date(const char *date, struct strbuf *out);
-int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
-int parse_expiry_date(const char *date, timestamp_t *timestamp);
-void datestamp(struct strbuf *out);
-#define approxidate(s) approxidate_careful((s), NULL)
-timestamp_t approxidate_careful(const char *, int *);
-timestamp_t approxidate_relative(const char *date);
-void parse_date_format(const char *format, struct date_mode *mode);
-int date_overflows(timestamp_t date);
-time_t tm_to_time_t(const struct tm *tm);
-
 #define IDENT_STRICT	       1
 #define IDENT_NO_DATE	       2
 #define IDENT_NO_NAME	       4
@@ -1645,14 +1605,6 @@ struct ident_split {
 int split_ident_line(struct ident_split *, const char *, int);
 
 /*
- * 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);
-
-/*
  * Compare split idents for equality or strict ordering. Note that we
  * compare only the ident part of the line, ignoring any timestamp.
  *
diff --git a/config.c b/config.c
index e0c03d154c..430868f1ec 100644
--- a/config.c
+++ b/config.c
@@ -6,6 +6,7 @@
  *
  */
 #include "cache.h"
+#include "date.h"
 #include "branch.h"
 #include "config.h"
 #include "environment.h"
diff --git a/date.c b/date.c
index 84bb4451c1..863b07e9e6 100644
--- a/date.c
+++ b/date.c
@@ -5,6 +5,7 @@
  */
 
 #include "cache.h"
+#include "date.h"
 
 /*
  * This is like mktime, but without normalization of tm_wday and tm_yday.
diff --git a/date.h b/date.h
new file mode 100644
index 0000000000..5db9ec8dd2
--- /dev/null
+++ b/date.h
@@ -0,0 +1,43 @@
+#ifndef DATE_H
+#define DATE_H
+
+enum date_mode_type {
+	DATE_NORMAL = 0,
+	DATE_HUMAN,
+	DATE_RELATIVE,
+	DATE_SHORT,
+	DATE_ISO8601,
+	DATE_ISO8601_STRICT,
+	DATE_RFC2822,
+	DATE_STRFTIME,
+	DATE_RAW,
+	DATE_UNIX
+};
+
+struct date_mode {
+	enum date_mode_type type;
+	const char *strftime_fmt;
+	int local;
+};
+
+/*
+ * Convenience helper for passing a constant type, like:
+ *
+ *   show_date(t, tz, DATE_MODE(NORMAL));
+ */
+#define DATE_MODE(t) date_mode_from_type(DATE_##t)
+struct date_mode *date_mode_from_type(enum date_mode_type type);
+
+const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
+void show_date_relative(timestamp_t time, struct strbuf *timebuf);
+int parse_date(const char *date, struct strbuf *out);
+int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
+int parse_expiry_date(const char *date, timestamp_t *timestamp);
+void datestamp(struct strbuf *out);
+#define approxidate(s) approxidate_careful((s), NULL)
+timestamp_t approxidate_careful(const char *, int *);
+timestamp_t approxidate_relative(const char *date);
+void parse_date_format(const char *format, struct date_mode *mode);
+int date_overflows(timestamp_t date);
+time_t tm_to_time_t(const struct tm *tm);
+#endif
diff --git a/http-backend.c b/http-backend.c
index 807fb8839e..81a7229ece 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -13,6 +13,7 @@
 #include "packfile.h"
 #include "object-store.h"
 #include "protocol.h"
+#include "date.h"
 
 static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
diff --git a/ident.c b/ident.c
index 6aba4b5cb6..89ca5b4700 100644
--- a/ident.c
+++ b/ident.c
@@ -7,6 +7,7 @@
  */
 #include "cache.h"
 #include "config.h"
+#include "date.h"
 
 static struct strbuf git_default_name = STRBUF_INIT;
 static struct strbuf git_default_email = STRBUF_INIT;
diff --git a/object-name.c b/object-name.c
index 92862eeb1a..060d892a97 100644
--- a/object-name.c
+++ b/object-name.c
@@ -15,6 +15,7 @@
 #include "submodule.h"
 #include "midx.h"
 #include "commit-reach.h"
+#include "date.h"
 
 static int get_oid_oneline(struct repository *r, const char *, struct object_id *, struct commit_list *);
 
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 */
diff --git a/reflog-walk.h b/reflog-walk.h
index f26408f6cc..e9e00ffd47 100644
--- a/reflog-walk.h
+++ b/reflog-walk.h
@@ -5,6 +5,7 @@
 
 struct commit;
 struct reflog_walk_info;
+struct date_mode;
 
 void init_reflog_walk(struct reflog_walk_info **info);
 int add_reflog_for_walk(struct reflog_walk_info *info,
diff --git a/refs.c b/refs.c
index 7017ae5980..b74f3815a5 100644
--- a/refs.c
+++ b/refs.c
@@ -19,6 +19,7 @@
 #include "strvec.h"
 #include "repository.h"
 #include "sigchain.h"
+#include "date.h"
 
 /*
  * List of all available backends
diff --git a/strbuf.c b/strbuf.c
index 613fee8c82..00abeb55af 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -2,6 +2,7 @@
 #include "refs.h"
 #include "string-list.h"
 #include "utf8.h"
+#include "date.h"
 
 int starts_with(const char *str, const char *prefix)
 {
diff --git a/t/helper/test-date.c b/t/helper/test-date.c
index 099eff4f0f..ded3d059f5 100644
--- a/t/helper/test-date.c
+++ b/t/helper/test-date.c
@@ -1,5 +1,6 @@
 #include "test-tool.h"
 #include "cache.h"
+#include "date.h"
 
 static const char *usage_msg = "\n"
 "  test-tool date relative [time_t]...\n"