parse-options: make CMDMODE errors more precise

Only a single PARSE_OPT_CMDMODE option can be specified for the same variable at the same time. This is enforced by get_value(), but the error messages are imprecise in three ways: 1. If a non-PARSE_OPT_CMDMODE option changes the value variable of a PARSE_OPT_CMDMODE option then an ominously vague message is shown: $ t/helper/test-tool parse-options --set23 --mode1 error: option `mode1' : incompatible with something else Worse: If the order of options is reversed then no error is reported at all: $ t/helper/test-tool parse-options --mode1 --set23 boolean: 0 integer: 23 magnitude: 0 timestamp: 0 string: (not set) abbrev: 7 verbose: -1 quiet: 0 dry run: no file: (not set) Fortunately this can currently only happen in the test helper; actual Git commands don't share the same variable for the value of options with and without the flag PARSE_OPT_CMDMODE. 2. If there are multiple options with the same value (synonyms), then the one that is defined first is shown rather than the one actually given on the command line, which is confusing: $ git am --resolved --quit error: option `quit' is incompatible with --continue 3. Arguments of PARSE_OPT_CMDMODE options are not handled by the parse-option machinery. This is left to the callback function. We currently only have a single affected option, --show-current-patch of git am. Errors for it can show an argument that was not actually given on the command line: $ git am --show-current-patch --show-current-patch=diff error: options '--show-current-patch=diff' and '--show-current-patch=raw' cannot be used together The options --show-current-patch and --show-current-patch=raw are synonyms, but the error accuses the user of input they did not actually made. Or it can awkwardly print a NULL pointer: $ git am --show-current-patch=diff --show-current-patch error: options '--show-current-patch=(null)' and '--show-current-patch=diff' cannot be used together The reasons for these shortcomings is that the current code checks incompatibility only when encountering a PARSE_OPT_CMDMODE option at the command line, and that it searches the previous incompatible option by value. Fix the first two points by checking all PARSE_OPT_CMDMODE variables after parsing each option and by storing all relevant details if their value changed. Do that whether or not the changing options has the flag PARSE_OPT_CMDMODE set. Report an incompatibility only if two options change the variable to different values and at least one of them is a PARSE_OPT_CMDMODE option. This changes the output of the first three examples above to: $ t/helper/test-tool parse-options --set23 --mode1 error: --mode1 is incompatible with --set23 $ t/helper/test-tool parse-options --mode1 --set23 error: --set23 is incompatible with --mode1 $ git am --resolved --quit error: --quit is incompatible with --resolved Store the argument of PARSE_OPT_CMDMODE options of type OPTION_CALLBACK as well to allow taking over the responsibility for compatibility checking from the callback function. The next patch will use this capability to fix the messages for git am --show-current-patch. Use a linked list for storing the PARSE_OPT_CMDMODE variables. This somewhat outdated data structure is simple and suffices, as the number of elements per command is currently only zero or one. We do support multiple different command modes variables per command, but I don't expect that we'd ever use a significant number of them. Once we do we can switch to a hashmap. Since we no longer need to search the conflicting option, the all_opts parameter of get_value() is no longer used. Remove it. Extend the tests to check for both conflicting option names, but don't insist on a particular order. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-28 13:53:01 +02:00 · 2023-10-28 13:53:01 +02:00 · 0025dde775
--- a/parse-options.c
+++ b/parse-options.c
@ -70,42 +70,10 @@ static void fix_filename(const char *prefix, char **file)
 		*file = prefix_filename_except_for_dash(prefix, *file);
 }

-static enum parse_opt_result opt_command_mode_error(
-	const struct option *opt,
-	const struct option *all_opts,
-	enum opt_parsed flags)
-{
-	const struct option *that;
-	struct strbuf that_name = STRBUF_INIT;
-
-	/*
-	 * Find the other option that was used to set the variable
-	 * already, and report that this is not compatible with it.
-	 */
-	for (that = all_opts; that->type != OPTION_END; that++) {
-		if (that == opt ||
-		    !(that->flags & PARSE_OPT_CMDMODE) ||
-		    that->value != opt->value ||
-		    that->defval != *(int *)opt->value)
-			continue;
-
-		if (that->long_name)
-			strbuf_addf(&that_name, "--%s", that->long_name);
-		else
-			strbuf_addf(&that_name, "-%c", that->short_name);
-		error(_("%s is incompatible with %s"),
-		      optname(opt, flags), that_name.buf);
-		strbuf_release(&that_name);
-		return PARSE_OPT_ERROR;
-	}
-	return error(_("%s : incompatible with something else"),
-		     optname(opt, flags));
-}
-
-static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
-				       const struct option *opt,
-				       const struct option *all_opts,
-				       enum opt_parsed flags)
+static enum parse_opt_result do_get_value(struct parse_opt_ctx_t *p,
+					  const struct option *opt,
+					  enum opt_parsed flags,
+					  const char **argp)
 {
 	const char *s, *arg;
 	const int unset = flags & OPT_UNSET;
@ -118,14 +86,6 @@ static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
 	if (!(flags & OPT_SHORT) && p->opt && (opt->flags & PARSE_OPT_NOARG))
 		return error(_("%s takes no value"), optname(opt, flags));

-	/*
-	 * Giving the same mode option twice, although unnecessary,
-	 * is not a grave error, so let it pass.
-	 */
-	if ((opt->flags & PARSE_OPT_CMDMODE) &&
-	    *(int *)opt->value && *(int *)opt->value != opt->defval)
-		return opt_command_mode_error(opt, all_opts, flags);
-
 	switch (opt->type) {
 	case OPTION_LOWLEVEL_CALLBACK:
 		return opt->ll_callback(p, opt, NULL, unset);
@ -200,6 +160,8 @@ static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
 			p_unset = 0;
 			p_arg = arg;
 		}
+		if (opt->flags & PARSE_OPT_CMDMODE)
+			*argp = p_arg;
 		if (opt->callback)
 			return (*opt->callback)(opt, p_arg, p_unset) ? (-1) : 0;
 		else
@ -247,16 +209,91 @@ static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
 	}
 }

+struct parse_opt_cmdmode_list {
+	int value, *value_ptr;
+	const struct option *opt;
+	const char *arg;
+	enum opt_parsed flags;
+	struct parse_opt_cmdmode_list *next;
+};
+
+static void build_cmdmode_list(struct parse_opt_ctx_t *ctx,
+			       const struct option *opts)
+{
+	ctx->cmdmode_list = NULL;
+
+	for (; opts->type != OPTION_END; opts++) {
+		struct parse_opt_cmdmode_list *elem = ctx->cmdmode_list;
+		int *value_ptr = opts->value;
+
+		if (!(opts->flags & PARSE_OPT_CMDMODE) || !value_ptr)
+			continue;
+
+		while (elem && elem->value_ptr != value_ptr)
+			elem = elem->next;
+		if (elem)
+			continue;
+
+		CALLOC_ARRAY(elem, 1);
+		elem->value_ptr = value_ptr;
+		elem->value = *value_ptr;
+		elem->next = ctx->cmdmode_list;
+		ctx->cmdmode_list = elem;
+	}
+}
+
+static char *optnamearg(const struct option *opt, const char *arg,
+			enum opt_parsed flags)
+{
+	if (flags & OPT_SHORT)
+		return xstrfmt("-%c%s", opt->short_name, arg ? arg : "");
+	return xstrfmt("--%s%s%s%s", flags & OPT_UNSET ? "no-" : "",
+		       opt->long_name, arg ? "=" : "", arg ? arg : "");
+}
+
+static enum parse_opt_result get_value(struct parse_opt_ctx_t *p,
+				       const struct option *opt,
+				       enum opt_parsed flags)
+{
+	const char *arg = NULL;
+	enum parse_opt_result result = do_get_value(p, opt, flags, &arg);
+	struct parse_opt_cmdmode_list *elem = p->cmdmode_list;
+	char *opt_name, *other_opt_name;
+
+	for (; elem; elem = elem->next) {
+		if (*elem->value_ptr == elem->value)
+			continue;
+
+		if (elem->opt &&
+		    (elem->opt->flags | opt->flags) & PARSE_OPT_CMDMODE)
+			break;
+
+		elem->opt = opt;
+		elem->arg = arg;
+		elem->flags = flags;
+		elem->value = *elem->value_ptr;
+	}
+
+	if (result || !elem)
+		return result;
+
+	opt_name = optnamearg(opt, arg, flags);
+	other_opt_name = optnamearg(elem->opt, elem->arg, elem->flags);
+	error(_("%s is incompatible with %s"), opt_name, other_opt_name);
+	free(opt_name);
+	free(other_opt_name);
+	return -1;
+}
+
 static enum parse_opt_result parse_short_opt(struct parse_opt_ctx_t *p,
 					     const struct option *options)
 {
-	const struct option *all_opts = options;
 	const struct option *numopt = NULL;

 	for (; options->type != OPTION_END; options++) {
 		if (options->short_name == *p->opt) {
 			p->opt = p->opt[1] ? p->opt + 1 : NULL;
-			return get_value(p, options, all_opts, OPT_SHORT);
+			return get_value(p, options, OPT_SHORT);
 		}

 		/*
@ -318,7 +355,6 @@ static enum parse_opt_result parse_long_opt(
 	struct parse_opt_ctx_t *p, const char *arg,
 	const struct option *options)
 {
-	const struct option *all_opts = options;
 	const char *arg_end = strchrnul(arg, '=');
 	const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
 	enum opt_parsed abbrev_flags = OPT_LONG, ambiguous_flags = OPT_LONG;
@ -387,7 +423,7 @@ is_abbreviated:
 				continue;
 			p->opt = rest + 1;
 		}
-		return get_value(p, options, all_opts, flags ^ opt_flags);
+		return get_value(p, options, flags ^ opt_flags);
 	}

 	if (disallow_abbreviated_options && (ambiguous_option || abbrev_option))
@ -405,7 +441,7 @@ is_abbreviated:
 		return PARSE_OPT_HELP;
 	}
 	if (abbrev_option)
-		return get_value(p, abbrev_option, all_opts, abbrev_flags);
+		return get_value(p, abbrev_option, abbrev_flags);
 	return PARSE_OPT_UNKNOWN;
 }

@ -413,13 +449,11 @@ static enum parse_opt_result parse_nodash_opt(struct parse_opt_ctx_t *p,
 					      const char *arg,
 					      const struct option *options)
 {
-	const struct option *all_opts = options;
-
 	for (; options->type != OPTION_END; options++) {
 		if (!(options->flags & PARSE_OPT_NODASH))
 			continue;
 		if (options->short_name == arg[0] && arg[1] == '\0')
-			return get_value(p, options, all_opts, OPT_SHORT);
+			return get_value(p, options, OPT_SHORT);
 	}
 	return PARSE_OPT_ERROR;
 }
@ -574,6 +608,7 @@ static void parse_options_start_1(struct parse_opt_ctx_t *ctx,
 	    (flags & PARSE_OPT_KEEP_ARGV0))
 		BUG("Can't keep argv0 if you don't have it");
 	parse_options_check(options);
+	build_cmdmode_list(ctx, options);
 }

 void parse_options_start(struct parse_opt_ctx_t *ctx,
@ -1006,6 +1041,11 @@ int parse_options(int argc, const char **argv,
 	precompose_argv_prefix(argc, argv, NULL);
 	free_preprocessed_options(real_options);
 	free(ctx.alias_groups);
+	for (struct parse_opt_cmdmode_list *elem = ctx.cmdmode_list; elem;) {
+		struct parse_opt_cmdmode_list *next = elem->next;
+		free(elem);
+		elem = next;
+	}
 	return parse_options_end(&ctx);
 }

--- a/parse-options.h
+++ b/parse-options.h
@ -445,6 +445,8 @@ static inline void die_for_incompatible_opt3(int opt1, const char *opt1_name,

 /*----- incremental advanced APIs -----*/

+struct parse_opt_cmdmode_list;
+
 /*
 * It's okay for the caller to consume argv/argc in the usual way.
 * Other fields of that structure are private to parse-options and should not
@ -459,6 +461,7 @@ struct parse_opt_ctx_t {
 	unsigned has_subcommands;
 	const char *prefix;
 	const char **alias_groups; /* must be in groups of 3 elements! */
+	struct parse_opt_cmdmode_list *cmdmode_list;
 };

 void parse_options_start(struct parse_opt_ctx_t *ctx,
--- a/t/helper/test-parse-options.c
+++ b/t/helper/test-parse-options.c
@ -21,6 +21,19 @@ static struct {
 	int unset;
 } length_cb;

+static int mode34_callback(const struct option *opt, const char *arg, int unset)
+{
+	if (unset)
+		*(int *)opt->value = 0;
+	else if (!strcmp(arg, "3"))
+		*(int *)opt->value = 3;
+	else if (!strcmp(arg, "4"))
+		*(int *)opt->value = 4;
+	else
+		return error("invalid value for '%s': '%s'", "--mode34", arg);
+	return 0;
+}
+
 static int length_callback(const struct option *opt, const char *arg, int unset)
 {
 	length_cb.called = 1;
@ -124,6 +137,9 @@ int cmd__parse_options(int argc, const char **argv)
 		OPT_SET_INT(0, "set23", &integer, "set integer to 23", 23),
 		OPT_CMDMODE(0, "mode1", &integer, "set integer to 1 (cmdmode option)", 1),
 		OPT_CMDMODE(0, "mode2", &integer, "set integer to 2 (cmdmode option)", 2),
+		OPT_CALLBACK_F(0, "mode34", &integer, "(3|4)",
+			"set integer to 3 or 4 (cmdmode option)",
+			PARSE_OPT_CMDMODE, mode34_callback),
 		OPT_CALLBACK('L', "length", &integer, "str",
 			"get length of <str>", length_callback),
 		OPT_FILENAME('F', "file", &file, "set file to <file>"),
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@ -28,6 +28,7 @@ usage: test-tool parse-options <options>
    --[no-]set23          set integer to 23
    --mode1               set integer to 1 (cmdmode option)
    --mode2               set integer to 2 (cmdmode option)
+    --[no-]mode34 (3|4)   set integer to 3 or 4 (cmdmode option)
    -L, --[no-]length <str>
                          get length of <str>
    -F, --[no-]file <file>
@ -366,19 +367,41 @@ test_expect_success 'OPT_NEGBIT() works' '
 '

 test_expect_success 'OPT_CMDMODE() works' '
-	test-tool parse-options --expect="integer: 1" --mode1
+	test-tool parse-options --expect="integer: 1" --mode1 &&
+	test-tool parse-options --expect="integer: 3" --mode34=3
 '

-test_expect_success 'OPT_CMDMODE() detects incompatibility' '
+test_expect_success 'OPT_CMDMODE() detects incompatibility (1)' '
 	test_must_fail test-tool parse-options --mode1 --mode2 >output 2>output.err &&
 	test_must_be_empty output &&
-	test_i18ngrep "incompatible with --mode" output.err
+	test_i18ngrep "mode1" output.err &&
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "is incompatible with" output.err
 '

-test_expect_success 'OPT_CMDMODE() detects incompatibility with something else' '
+test_expect_success 'OPT_CMDMODE() detects incompatibility (2)' '
 	test_must_fail test-tool parse-options --set23 --mode2 >output 2>output.err &&
 	test_must_be_empty output &&
-	test_i18ngrep "incompatible with something else" output.err
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "set23" output.err &&
+	test_i18ngrep "is incompatible with" output.err
+'
+
+test_expect_success 'OPT_CMDMODE() detects incompatibility (3)' '
+	test_must_fail test-tool parse-options --mode2 --set23 >output 2>output.err &&
+	test_must_be_empty output &&
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "set23" output.err &&
+	test_i18ngrep "is incompatible with" output.err
+'
+
+test_expect_success 'OPT_CMDMODE() detects incompatibility (4)' '
+	test_must_fail test-tool parse-options --mode2 --mode34=3 \
+		>output 2>output.err &&
+	test_must_be_empty output &&
+	test_i18ngrep "mode2" output.err &&
+	test_i18ngrep "mode34.3" output.err &&
+	test_i18ngrep "is incompatible with" output.err
 '

 test_expect_success 'OPT_COUNTUP() with PARSE_OPT_NODASH works' '