diff_opt: track whether flags have been set explicitly

gitster · gitster · commit 6c374008b1a4 · 2013-05-10T10:24:17.000-07:00
The diff_opt infrastructure sets flags based on defaults and command
line options.  It is impossible to tell whether a flag has been set
as a default or on explicit request.  Update the structure so that
this detection is possible:

 * Add an extra "opt-&gt;touched_flags" that keeps track of all the
   fields that have been touched by DIFF_OPT_SET and DIFF_OPT_CLR.

 * You may continue setting the default values to the flags, like
   commands in the "log" family do in cmd_log_init_defaults(), but
   after you finished setting the defaults, you clear the
   touched_flags field;

 * And then you let the usual callchain call diff_opt_parse(),
   allowing the opt-&gt;flags be set or unset, while keeping track of
   which bits the user touched;

 * There is an optional callback "opt-&gt;set_default" that is called
   at the very beginning to let you inspect touched_flags and update
   opt-&gt;flags appropriately, before the remainder of the diffcore
   machinery is set up, taking the opt-&gt;flags value into account.

Signed-off-by: Michael J Gruber &lt;git@drmicha.warpmail.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Documentation/technical/api-diff.txt b/Documentation/technical/api-diff.txt
@@ -28,7 +28,8 @@ Calling sequence
 
 * Call `diff_setup_done()`; this inspects the options set up so far for
   internal consistency and make necessary tweaking to it (e.g. if
-  textual patch output was asked, recursive behaviour is turned on).
+  textual patch output was asked, recursive behaviour is turned on);
+  the callback set_default in diff_options can be used to tweak this more.
 
 * As you find different pairs of files, call `diff_change()` to feed
   modified files, `diff_addremove()` to feed created or deleted files,
@@ -115,6 +116,13 @@ Notable members are:
 	operation, but some do not have anything to do with the diffcore
 	library.
 
+`touched_flags`::
+	Records whether a flag has been changed due to user request
+	(rather than just set/unset by default).
+
+`set_default`::
+	Callback which allows tweaking the options in diff_setup_done().
+
 BINARY, TEXT;;
 	Affects the way how a file that is seemingly binary is treated.
 
diff --git a/builtin/log.c b/builtin/log.c
@@ -91,6 +91,7 @@ static void cmd_log_init_defaults(struct rev_info *rev)
 
 	if (default_date_mode)
 		rev->date_mode = parse_date_format(default_date_mode);
+	rev->diffopt.touched_flags = 0;
 }
 
 static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
diff --git a/diff.c b/diff.c
@@ -3213,6 +3213,9 @@ void diff_setup_done(struct diff_options *options)
 {
 	int count = 0;
 
+	if (options->set_default)
+		options->set_default(options);
+
 	if (options->output_format & DIFF_FORMAT_NAME)
 		count++;
 	if (options->output_format & DIFF_FORMAT_NAME_STATUS)
diff --git a/diff.h b/diff.h
@@ -87,8 +87,9 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 #define DIFF_OPT_PICKAXE_IGNORE_CASE (1 << 30)
 
 #define DIFF_OPT_TST(opts, flag)    ((opts)->flags & DIFF_OPT_##flag)
-#define DIFF_OPT_SET(opts, flag)    ((opts)->flags |= DIFF_OPT_##flag)
-#define DIFF_OPT_CLR(opts, flag)    ((opts)->flags &= ~DIFF_OPT_##flag)
+#define DIFF_OPT_TOUCHED(opts, flag)    ((opts)->touched_flags & DIFF_OPT_##flag)
+#define DIFF_OPT_SET(opts, flag)    (((opts)->flags |= DIFF_OPT_##flag),((opts)->touched_flags |= DIFF_OPT_##flag))
+#define DIFF_OPT_CLR(opts, flag)    (((opts)->flags &= ~DIFF_OPT_##flag),((opts)->touched_flags |= DIFF_OPT_##flag))
 #define DIFF_XDL_TST(opts, flag)    ((opts)->xdl_opts & XDF_##flag)
 #define DIFF_XDL_SET(opts, flag)    ((opts)->xdl_opts |= XDF_##flag)
 #define DIFF_XDL_CLR(opts, flag)    ((opts)->xdl_opts &= ~XDF_##flag)
@@ -109,6 +110,7 @@ struct diff_options {
 	const char *single_follow;
 	const char *a_prefix, *b_prefix;
 	unsigned flags;
+	unsigned touched_flags;
 	int use_color;
 	int context;
 	int interhunkcontext;
@@ -145,6 +147,8 @@ struct diff_options {
 	/* to support internal diff recursion by --follow hack*/
 	int found_follow;
 
+	void (*set_default)(struct diff_options *);
+
 	FILE *file;
 	int close_file;
 

Original file line number	Diff line number	Diff line change
`@@ -91,6 +91,7 @@ static void cmd_log_init_defaults(struct rev_info *rev)`
`91`	`91`
`92`	`92`	`if (default_date_mode)`
`93`	`93`	`rev->date_mode = parse_date_format(default_date_mode);`
	`94`	`+ rev->diffopt.touched_flags = 0;`
`94`	`95`	`}`
`95`	`96`
`96`	`97`	`static void cmd_log_init_finish(int argc, const char *argv, const char prefix,`
Original file line number	Diff line number	Diff line change
`@@ -3213,6 +3213,9 @@ void diff_setup_done(struct diff_options *options)`
`3213`	`3213`	`{`
`3214`	`3214`	`int count = 0;`
`3215`	`3215`
	`3216`	`+ if (options->set_default)`
	`3217`	`+ options->set_default(options);`
	`3218`	`+`
`3216`	`3219`	`if (options->output_format & DIFF_FORMAT_NAME)`
`3217`	`3220`	`count++;`
`3218`	`3221`	`if (options->output_format & DIFF_FORMAT_NAME_STATUS)`