Merge branch 'nd/diff-parseopt'

The diff machinery, one of the oldest parts of the system, which
long predates the parse-options API, uses fairly long and complex
handcrafted option parser.  This is being rewritten to use the
parse-options API.

* nd/diff-parseopt:
  diff.c: convert --raw
  diff.c: convert -W|--[no-]function-context
  diff.c: convert -U|--unified
  diff.c: convert -u|-p|--patch
  diff.c: prepare to use parse_options() for parsing
  diff.h: avoid bit fields in struct diff_flags
  diff.h: keep forward struct declarations sorted
  parse-options: allow ll_callback with OPTION_CALLBACK
  parse-options: avoid magic return codes
  parse-options: stop abusing 'callback' for lowlevel callbacks
  parse-options: add OPT_BITOP()
  parse-options: disable option abbreviation with PARSE_OPT_KEEP_UNKNOWN
  parse-options: add one-shot mode
  parse-options.h: remove extern on function prototypes

Author: gitster

Documentation/diff-options.txt

@@ -36,7 +36,7 @@ endif::git-format-patch[]
 -U<n>::
 --unified=<n>::
 	Generate diffs with <n> lines of context instead of
-	the usual three.
+	the usual three. Implies `--patch`.
 ifndef::git-format-patch[]
 	Implies `-p`.
 endif::git-format-patch[]

builtin/blame.c

@@ -814,7 +814,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 		 * and are only included here to get included in the "-h"
 		 * output:
 		 */
-		{ OPTION_LOWLEVEL_CALLBACK, 0, "indent-heuristic", NULL, NULL, N_("Use an experimental heuristic to improve diffs"), PARSE_OPT_NOARG, parse_opt_unknown_cb },
+		{ OPTION_LOWLEVEL_CALLBACK, 0, "indent-heuristic", NULL, NULL, N_("Use an experimental heuristic to improve diffs"), PARSE_OPT_NOARG, NULL, 0, parse_opt_unknown_cb },
 
 		OPT_BIT(0, "minimal", &xdl_opts, N_("Spend extra cycles to find better match"), XDF_NEED_MINIMAL),
 		OPT_STRING('S', NULL, &revs_file, N_("file"), N_("Use revisions from <file> instead of calling git-rev-list")),

builtin/merge.c

@@ -113,12 +113,15 @@ static int option_parse_message(const struct option *opt,
 	return 0;
 }
 
-static int option_read_message(struct parse_opt_ctx_t *ctx,
-			       const struct option *opt, int unset)
+static enum parse_opt_result option_read_message(struct parse_opt_ctx_t *ctx,
+						 const struct option *opt,
+						 const char *arg_not_used,
+						 int unset)
 {
 	struct strbuf *buf = opt->value;
 	const char *arg;
 
+	BUG_ON_OPT_ARG(arg_not_used);
 	if (unset)
 		BUG("-F cannot be negated");
 
@@ -262,7 +265,7 @@ static struct option builtin_merge_options[] = {
 		option_parse_message),
 	{ OPTION_LOWLEVEL_CALLBACK, 'F', "file", &merge_msg, N_("path"),
 		N_("read message from file"), PARSE_OPT_NONEG,
-		(parse_opt_cb *) option_read_message },
+		NULL, 0, option_read_message },
 	OPT__VERBOSITY(&verbosity),
 	OPT_BOOL(0, "abort", &abort_current_merge,
 		N_("abort the current in-progress merge")),

builtin/update-index.c

@@ -848,14 +848,16 @@ static int parse_new_style_cacheinfo(const char *arg,
 	return 0;
 }
 
-static int cacheinfo_callback(struct parse_opt_ctx_t *ctx,
-				const struct option *opt, int unset)
+static enum parse_opt_result cacheinfo_callback(
+	struct parse_opt_ctx_t *ctx, const struct option *opt,
+	const char *arg, int unset)
 {
 	struct object_id oid;
 	unsigned int mode;
 	const char *path;
 
 	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 
 	if (!parse_new_style_cacheinfo(ctx->argv[1], &mode, &oid, &path)) {
 		if (add_cacheinfo(mode, &oid, path, 0))
@@ -874,12 +876,14 @@ static int cacheinfo_callback(struct parse_opt_ctx_t *ctx,
 	return 0;
 }
 
-static int stdin_cacheinfo_callback(struct parse_opt_ctx_t *ctx,
-			      const struct option *opt, int unset)
+static enum parse_opt_result stdin_cacheinfo_callback(
+	struct parse_opt_ctx_t *ctx, const struct option *opt,
+	const char *arg, int unset)
 {
 	int *nul_term_line = opt->value;
 
 	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 
 	if (ctx->argc != 1)
 		return error("option '%s' must be the last argument", opt->long_name);
@@ -888,26 +892,30 @@ static int stdin_cacheinfo_callback(struct parse_opt_ctx_t *ctx,
 	return 0;
 }
 
-static int stdin_callback(struct parse_opt_ctx_t *ctx,
-				const struct option *opt, int unset)
+static enum parse_opt_result stdin_callback(
+	struct parse_opt_ctx_t *ctx, const struct option *opt,
+	const char *arg, int unset)
 {
 	int *read_from_stdin = opt->value;
 
 	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 
 	if (ctx->argc != 1)
 		return error("option '%s' must be the last argument", opt->long_name);
 	*read_from_stdin = 1;
 	return 0;
 }
 
-static int unresolve_callback(struct parse_opt_ctx_t *ctx,
-				const struct option *opt, int unset)
+static enum parse_opt_result unresolve_callback(
+	struct parse_opt_ctx_t *ctx, const struct option *opt,
+	const char *arg, int unset)
 {
 	int *has_errors = opt->value;
 	const char *prefix = startup_info->prefix;
 
 	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 
 	/* consume remaining arguments. */
 	*has_errors = do_unresolve(ctx->argc, ctx->argv,
@@ -920,13 +928,15 @@ static int unresolve_callback(struct parse_opt_ctx_t *ctx,
 	return 0;
 }
 
-static int reupdate_callback(struct parse_opt_ctx_t *ctx,
-				const struct option *opt, int unset)
+static enum parse_opt_result reupdate_callback(
+	struct parse_opt_ctx_t *ctx, const struct option *opt,
+	const char *arg, int unset)
 {
 	int *has_errors = opt->value;
 	const char *prefix = startup_info->prefix;
 
 	BUG_ON_OPT_NEG(unset);
+	BUG_ON_OPT_ARG(arg);
 
 	/* consume remaining arguments. */
 	setup_work_tree();
@@ -986,7 +996,8 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 			N_("add the specified entry to the index"),
 			PARSE_OPT_NOARG | /* disallow --cacheinfo=<mode> form */
 			PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP,
-			(parse_opt_cb *) cacheinfo_callback},
+			NULL, 0,
+			cacheinfo_callback},
 		{OPTION_CALLBACK, 0, "chmod", &set_executable_bit, "(+|-)x",
 			N_("override the executable bit of the listed files"),
 			PARSE_OPT_NONEG,
@@ -1012,19 +1023,19 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		{OPTION_LOWLEVEL_CALLBACK, 0, "stdin", &read_from_stdin, NULL,
 			N_("read list of paths to be updated from standard input"),
 			PARSE_OPT_NONEG | PARSE_OPT_NOARG,
-			(parse_opt_cb *) stdin_callback},
+			NULL, 0, stdin_callback},
 		{OPTION_LOWLEVEL_CALLBACK, 0, "index-info", &nul_term_line, NULL,
 			N_("add entries from standard input to the index"),
 			PARSE_OPT_NONEG | PARSE_OPT_NOARG,
-			(parse_opt_cb *) stdin_cacheinfo_callback},
+			NULL, 0, stdin_cacheinfo_callback},
 		{OPTION_LOWLEVEL_CALLBACK, 0, "unresolve", &has_errors, NULL,
 			N_("repopulate stages #2 and #3 for the listed paths"),
 			PARSE_OPT_NONEG | PARSE_OPT_NOARG,
-			(parse_opt_cb *) unresolve_callback},
+			NULL, 0, unresolve_callback},
 		{OPTION_LOWLEVEL_CALLBACK, 'g', "again", &has_errors, NULL,
 			N_("only update entries that differ from HEAD"),
 			PARSE_OPT_NONEG | PARSE_OPT_NOARG,
-			(parse_opt_cb *) reupdate_callback},
+			NULL, 0, reupdate_callback},
 		OPT_BIT(0, "ignore-missing", &refresh_args.flags,
 			N_("ignore files missing from worktree"),
 			REFRESH_IGNORE_MISSING),

diff.c

@@ -23,6 +23,7 @@
 #include "argv-array.h"
 #include "graph.h"
 #include "packfile.h"
+#include "parse-options.h"
 #include "help.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
@@ -4491,6 +4492,8 @@ static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
 	builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
 }
 
+static void prep_parse_options(struct diff_options *options);
+
 void repo_diff_setup(struct repository *r, struct diff_options *options)
 {
 	memcpy(options, &default_diff_options, sizeof(*options));
@@ -4532,6 +4535,8 @@ void repo_diff_setup(struct repository *r, struct diff_options *options)
 
 	options->color_moved = diff_color_moved_default;
 	options->color_moved_ws_handling = diff_color_moved_ws_default;
+
+	prep_parse_options(options);
 }
 
 void diff_setup_done(struct diff_options *options)
@@ -4635,6 +4640,8 @@ void diff_setup_done(struct diff_options *options)
 
 	if (!options->use_color || external_diff())
 		options->color_moved = 0;
+
+	FREE_AND_NULL(options->parseopts);
 }
 
 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
@@ -4926,6 +4933,47 @@ static int parse_objfind_opt(struct diff_options *opt, const char *arg)
 	return 1;
 }
 
+static int diff_opt_unified(const struct option *opt,
+			    const char *arg, int unset)
+{
+	struct diff_options *options = opt->value;
+	char *s;
+
+	BUG_ON_OPT_NEG(unset);
+
+	options->context = strtol(arg, &s, 10);
+	if (*s)
+		return error(_("%s expects a numerical value"), "--unified");
+	enable_patch_output(&options->output_format);
+
+	return 0;
+}
+
+static void prep_parse_options(struct diff_options *options)
+{
+	struct option parseopts[] = {
+		OPT_GROUP(N_("Diff output format options")),
+		OPT_BITOP('p', "patch", &options->output_format,
+			  N_("generate patch"),
+			  DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
+		OPT_BITOP('u', NULL, &options->output_format,
+			  N_("generate patch"),
+			  DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
+		OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
+			       N_("generate diffs with <n> lines context"),
+			       PARSE_OPT_NONEG, diff_opt_unified),
+		OPT_BOOL('W', "function-context", &options->flags.funccontext,
+			 N_("generate diffs with <n> lines context")),
+		OPT_BIT_F(0, "raw", &options->output_format,
+			  N_("generate the diff in raw format"),
+			  DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
+		OPT_END()
+	};
+
+	ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
+	memcpy(options->parseopts, parseopts, sizeof(parseopts));
+}
+
 int diff_opt_parse(struct diff_options *options,
 		   const char **av, int ac, const char *prefix)
 {
@@ -4936,13 +4984,18 @@ int diff_opt_parse(struct diff_options *options,
 	if (!prefix)
 		prefix = "";
 
+	ac = parse_options(ac, av, prefix, options->parseopts, NULL,
+			   PARSE_OPT_KEEP_DASHDASH |
+			   PARSE_OPT_KEEP_UNKNOWN |
+			   PARSE_OPT_NO_INTERNAL_HELP |
+			   PARSE_OPT_ONE_SHOT |
+			   PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (ac)
+		return ac;
+
 	/* Output format options */
-	if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
-	    || opt_arg(arg, 'U', "unified", &options->context))
-		enable_patch_output(&options->output_format);
-	else if (!strcmp(arg, "--raw"))
-		options->output_format |= DIFF_FORMAT_RAW;
-	else if (!strcmp(arg, "--patch-with-raw")) {
+	if (!strcmp(arg, "--patch-with-raw")) {
 		enable_patch_output(&options->output_format);
 		options->output_format |= DIFF_FORMAT_RAW;
 	} else if (!strcmp(arg, "--numstat"))
@@ -5230,12 +5283,6 @@ int diff_opt_parse(struct diff_options *options,
 	else if (opt_arg(arg, '\0', "inter-hunk-context",
 			 &options->interhunkcontext))
 		;
-	else if (!strcmp(arg, "-W"))
-		options->flags.funccontext = 1;
-	else if (!strcmp(arg, "--function-context"))
-		options->flags.funccontext = 1;
-	else if (!strcmp(arg, "--no-function-context"))
-		options->flags.funccontext = 0;
 	else if ((argcount = parse_long_opt("output", av, &optarg))) {
 		char *path = prefix_filename(prefix, optarg);
 		options->file = xfopen(path, "w");

diff.h

@@ -9,16 +9,17 @@
 #include "object.h"
 #include "oidset.h"
 
-struct rev_info;
+struct combine_diff_path;
+struct commit;
+struct diff_filespec;
 struct diff_options;
 struct diff_queue_struct;
-struct strbuf;
-struct diff_filespec;
-struct userdiff_driver;
 struct oid_array;
-struct commit;
-struct combine_diff_path;
+struct option;
 struct repository;
+struct rev_info;
+struct strbuf;
+struct userdiff_driver;
 
 typedef int (*pathchange_fn_t)(struct diff_options *options,
 		 struct combine_diff_path *path);
@@ -64,39 +65,39 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 
 #define DIFF_FLAGS_INIT { 0 }
 struct diff_flags {
-	unsigned recursive:1;
-	unsigned tree_in_recursive:1;
-	unsigned binary:1;
-	unsigned text:1;
-	unsigned full_index:1;
-	unsigned silent_on_remove:1;
-	unsigned find_copies_harder:1;
-	unsigned follow_renames:1;
-	unsigned rename_empty:1;
-	unsigned has_changes:1;
-	unsigned quick:1;
-	unsigned no_index:1;
-	unsigned allow_external:1;
-	unsigned exit_with_status:1;
-	unsigned reverse_diff:1;
-	unsigned check_failed:1;
-	unsigned relative_name:1;
-	unsigned ignore_submodules:1;
-	unsigned dirstat_cumulative:1;
-	unsigned dirstat_by_file:1;
-	unsigned allow_textconv:1;
-	unsigned textconv_set_via_cmdline:1;
-	unsigned diff_from_contents:1;
-	unsigned dirty_submodules:1;
-	unsigned ignore_untracked_in_submodules:1;
-	unsigned ignore_dirty_submodules:1;
-	unsigned override_submodule_config:1;
-	unsigned dirstat_by_line:1;
-	unsigned funccontext:1;
-	unsigned default_follow_renames:1;
-	unsigned stat_with_summary:1;
-	unsigned suppress_diff_headers:1;
-	unsigned dual_color_diffed_diffs:1;
+	unsigned recursive;
+	unsigned tree_in_recursive;
+	unsigned binary;
+	unsigned text;
+	unsigned full_index;
+	unsigned silent_on_remove;
+	unsigned find_copies_harder;
+	unsigned follow_renames;
+	unsigned rename_empty;
+	unsigned has_changes;
+	unsigned quick;
+	unsigned no_index;
+	unsigned allow_external;
+	unsigned exit_with_status;
+	unsigned reverse_diff;
+	unsigned check_failed;
+	unsigned relative_name;
+	unsigned ignore_submodules;
+	unsigned dirstat_cumulative;
+	unsigned dirstat_by_file;
+	unsigned allow_textconv;
+	unsigned textconv_set_via_cmdline;
+	unsigned diff_from_contents;
+	unsigned dirty_submodules;
+	unsigned ignore_untracked_in_submodules;
+	unsigned ignore_dirty_submodules;
+	unsigned override_submodule_config;
+	unsigned dirstat_by_line;
+	unsigned funccontext;
+	unsigned default_follow_renames;
+	unsigned stat_with_summary;
+	unsigned suppress_diff_headers;
+	unsigned dual_color_diffed_diffs;
 };
 
 static inline void diff_flags_or(struct diff_flags *a,
@@ -229,6 +230,7 @@ struct diff_options {
 	unsigned color_moved_ws_handling;
 
 	struct repository *repo;
+	struct option *parseopts;
 };
 
 void diff_emit_submodule_del(struct diff_options *o, const char *line);