Merge branch 'jk/unused-params-even-more'
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index 1a1f21578766e5fa6c455c94cce358ccad5de1d1..6dfad79f1d67e9659eaaa207bf7a3e7c6a596a6b 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -104,11 +104,6 @@ static const char *color_diff_slots[] = {
        [DIFF_FILE_NEW_BOLD]          = "newBold",
 };
 
-static NORETURN void die_want_option(const char *option_name)
-{
-       die(_("option '%s' requires a value"), option_name);
-}
-
 define_list_config_array_extra(color_diff_slots, {"plain"});
 
 static int parse_diff_color_slot(const char *var)
@@ -179,6 +174,10 @@ static int parse_submodule_params(struct diff_options *options, const char *valu
                options->submodule_format = DIFF_SUBMODULE_SHORT;
        else if (!strcmp(value, "diff"))
                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
+       /*
+        * Please update $__git_diff_submodule_formats in
+        * git-completion.bash when you add new formats.
+        */
        else
                return -1;
        return 0;
@@ -205,6 +204,10 @@ long parse_algorithm_value(const char *value)
                return XDF_PATIENCE_DIFF;
        else if (!strcasecmp(value, "histogram"))
                return XDF_HISTOGRAM_DIFF;
+       /*
+        * Please update $__git_diff_algorithms in git-completion.bash
+        * when you add new algorithms.
+        */
        return -1;
 }
 
@@ -1614,8 +1617,7 @@ static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line
        return ws_blank_line(line, len, ecbdata->ws_rule);
 }
 
-static void emit_add_line(const char *reset,
-                         struct emit_callback *ecbdata,
+static void emit_add_line(struct emit_callback *ecbdata,
                          const char *line, int len)
 {
        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
@@ -1625,16 +1627,14 @@ static void emit_add_line(const char *reset,
        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 }
 
-static void emit_del_line(const char *reset,
-                         struct emit_callback *ecbdata,
+static void emit_del_line(struct emit_callback *ecbdata,
                          const char *line, int len)
 {
        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
 }
 
-static void emit_context_line(const char *reset,
-                             struct emit_callback *ecbdata,
+static void emit_context_line(struct emit_callback *ecbdata,
                              const char *line, int len)
 {
        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
@@ -1743,7 +1743,6 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                               int prefix, const char *data, int size)
 {
        const char *endp = NULL;
-       const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 
        while (0 < size) {
                int len;
@@ -1752,10 +1751,10 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                len = endp ? (endp - data + 1) : size;
                if (prefix != '+') {
                        ecb->lno_in_preimage++;
-                       emit_del_line(reset, ecb, data, len);
+                       emit_del_line(ecb, data, len);
                } else {
                        ecb->lno_in_postimage++;
-                       emit_add_line(reset, ecb, data, len);
+                       emit_add_line(ecb, data, len);
                }
                size -= len;
                data += len;
@@ -2292,7 +2291,7 @@ const char *diff_line_prefix(struct diff_options *opt)
        return msgbuf->buf;
 }
 
-static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
+static unsigned long sane_truncate_line(char *line, unsigned long len)
 {
        const char *cp;
        unsigned long allot;
@@ -2326,7 +2325,6 @@ static void find_lno(const char *line, struct emit_callback *ecbdata)
 static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
        struct emit_callback *ecbdata = priv;
-       const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
        struct diff_options *o = ecbdata->opt;
 
        o->found_changes = 1;
@@ -2357,7 +2355,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        if (line[0] == '@') {
                if (ecbdata->diff_words)
                        diff_words_flush(ecbdata);
-               len = sane_truncate_line(ecbdata, line, len);
+               len = sane_truncate_line(line, len);
                find_lno(line, ecbdata);
                emit_hunk_header(ecbdata, line, len);
                return;
@@ -2393,16 +2391,16 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        switch (line[0]) {
        case '+':
                ecbdata->lno_in_postimage++;
-               emit_add_line(reset, ecbdata, line + 1, len - 1);
+               emit_add_line(ecbdata, line + 1, len - 1);
                break;
        case '-':
                ecbdata->lno_in_preimage++;
-               emit_del_line(reset, ecbdata, line + 1, len - 1);
+               emit_del_line(ecbdata, line + 1, len - 1);
                break;
        case ' ':
                ecbdata->lno_in_postimage++;
                ecbdata->lno_in_preimage++;
-               emit_context_line(reset, ecbdata, line + 1, len - 1);
+               emit_context_line(ecbdata, line + 1, len - 1);
                break;
        default:
                /* incomplete line at the end */
@@ -4184,7 +4182,6 @@ static void run_external_diff(const char *pgm,
                              struct diff_filespec *one,
                              struct diff_filespec *two,
                              const char *xfrm_msg,
-                             int complete_rewrite,
                              struct diff_options *o)
 {
        struct argv_array argv = ARGV_ARRAY_INIT;
@@ -4342,8 +4339,7 @@ static void run_diff_cmd(const char *pgm,
        }
 
        if (pgm) {
-               run_external_diff(pgm, name, other, one, two, xfrm_msg,
-                                 complete_rewrite, o);
+               run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
                return;
        }
        if (one && two)
@@ -4688,8 +4684,6 @@ static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *va
        return 1;
 }
 
-static int diff_scoreopt_parse(const char *opt);
-
 static inline int short_opt(char opt, const char **argv,
                            const char **optarg)
 {
@@ -4727,77 +4721,56 @@ int parse_long_opt(const char *opt, const char **argv,
        return 2;
 }
 
-static int stat_opt(struct diff_options *options, const char **av)
+static int diff_opt_stat(const struct option *opt, const char *value, int unset)
 {
-       const char *arg = av[0];
-       char *end;
+       struct diff_options *options = opt->value;
        int width = options->stat_width;
        int name_width = options->stat_name_width;
        int graph_width = options->stat_graph_width;
        int count = options->stat_count;
-       int argcount = 1;
+       char *end;
 
-       if (!skip_prefix(arg, "--stat", &arg))
-               BUG("stat option does not begin with --stat: %s", arg);
-       end = (char *)arg;
+       BUG_ON_OPT_NEG(unset);
 
-       switch (*arg) {
-       case '-':
-               if (skip_prefix(arg, "-width", &arg)) {
-                       if (*arg == '=')
-                               width = strtoul(arg + 1, &end, 10);
-                       else if (!*arg && !av[1])
-                               die_want_option("--stat-width");
-                       else if (!*arg) {
-                               width = strtoul(av[1], &end, 10);
-                               argcount = 2;
-                       }
-               } else if (skip_prefix(arg, "-name-width", &arg)) {
-                       if (*arg == '=')
-                               name_width = strtoul(arg + 1, &end, 10);
-                       else if (!*arg && !av[1])
-                               die_want_option("--stat-name-width");
-                       else if (!*arg) {
-                               name_width = strtoul(av[1], &end, 10);
-                               argcount = 2;
-                       }
-               } else if (skip_prefix(arg, "-graph-width", &arg)) {
-                       if (*arg == '=')
-                               graph_width = strtoul(arg + 1, &end, 10);
-                       else if (!*arg && !av[1])
-                               die_want_option("--stat-graph-width");
-                       else if (!*arg) {
-                               graph_width = strtoul(av[1], &end, 10);
-                               argcount = 2;
-                       }
-               } else if (skip_prefix(arg, "-count", &arg)) {
-                       if (*arg == '=')
-                               count = strtoul(arg + 1, &end, 10);
-                       else if (!*arg && !av[1])
-                               die_want_option("--stat-count");
-                       else if (!*arg) {
-                               count = strtoul(av[1], &end, 10);
-                               argcount = 2;
-                       }
+       if (!strcmp(opt->long_name, "stat")) {
+               if (value) {
+                       width = strtoul(value, &end, 10);
+                       if (*end == ',')
+                               name_width = strtoul(end+1, &end, 10);
+                       if (*end == ',')
+                               count = strtoul(end+1, &end, 10);
+                       if (*end)
+                               return error(_("invalid --stat value: %s"), value);
                }
-               break;
-       case '=':
-               width = strtoul(arg+1, &end, 10);
-               if (*end == ',')
-                       name_width = strtoul(end+1, &end, 10);
-               if (*end == ',')
-                       count = strtoul(end+1, &end, 10);
-       }
+       } else if (!strcmp(opt->long_name, "stat-width")) {
+               width = strtoul(value, &end, 10);
+               if (*end)
+                       return error(_("%s expects a numerical value"),
+                                    opt->long_name);
+       } else if (!strcmp(opt->long_name, "stat-name-width")) {
+               name_width = strtoul(value, &end, 10);
+               if (*end)
+                       return error(_("%s expects a numerical value"),
+                                    opt->long_name);
+       } else if (!strcmp(opt->long_name, "stat-graph-width")) {
+               graph_width = strtoul(value, &end, 10);
+               if (*end)
+                       return error(_("%s expects a numerical value"),
+                                    opt->long_name);
+       } else if (!strcmp(opt->long_name, "stat-count")) {
+               count = strtoul(value, &end, 10);
+               if (*end)
+                       return error(_("%s expects a numerical value"),
+                                    opt->long_name);
+       } else
+               BUG("%s should not get here", opt->long_name);
 
-       /* Important! This checks all the error cases! */
-       if (*end)
-               return 0;
        options->output_format |= DIFF_FORMAT_DIFFSTAT;
        options->stat_name_width = name_width;
        options->stat_graph_width = graph_width;
        options->stat_width = width;
        options->stat_count = count;
-       return argcount;
+       return 0;
 }
 
 static int parse_dirstat_opt(struct diff_options *options, const char *params)
@@ -4815,14 +4788,6 @@ static int parse_dirstat_opt(struct diff_options *options, const char *params)
        return 1;
 }
 
-static int parse_submodule_opt(struct diff_options *options, const char *value)
-{
-       if (parse_submodule_params(options, value))
-               die(_("Failed to parse --submodule option parameter: '%s'"),
-                       value);
-       return 1;
-}
-
 static const char diff_status_letters[] = {
        DIFF_STATUS_ADDED,
        DIFF_STATUS_COPIED,
@@ -4933,6 +4898,271 @@ static int parse_objfind_opt(struct diff_options *opt, const char *arg)
        return 1;
 }
 
+static int diff_opt_anchored(const struct option *opt,
+                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
+       ALLOC_GROW(options->anchors, options->anchors_nr + 1,
+                  options->anchors_alloc);
+       options->anchors[options->anchors_nr++] = xstrdup(arg);
+       return 0;
+}
+
+static int diff_opt_binary(const struct option *opt,
+                          const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       BUG_ON_OPT_ARG(arg);
+       enable_patch_output(&options->output_format);
+       options->flags.binary = 1;
+       return 0;
+}
+
+static int diff_opt_break_rewrites(const struct option *opt,
+                                  const char *arg, int unset)
+{
+       int *break_opt = opt->value;
+       int opt1, opt2;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "";
+       opt1 = parse_rename_score(&arg);
+       if (*arg == 0)
+               opt2 = 0;
+       else if (*arg != '/')
+               return error(_("%s expects <n>/<m> form"), opt->long_name);
+       else {
+               arg++;
+               opt2 = parse_rename_score(&arg);
+       }
+       if (*arg != 0)
+               return error(_("%s expects <n>/<m> form"), opt->long_name);
+       *break_opt = opt1 | (opt2 << 16);
+       return 0;
+}
+
+static int diff_opt_char(const struct option *opt,
+                        const char *arg, int unset)
+{
+       char *value = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (arg[1])
+               return error(_("%s expects a character, got '%s'"),
+                            opt->long_name, arg);
+       *value = arg[0];
+       return 0;
+}
+
+static int diff_opt_color_words(const struct option *opt,
+                               const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       options->use_color = 1;
+       options->word_diff = DIFF_WORDS_COLOR;
+       options->word_regex = arg;
+       return 0;
+}
+
+static int diff_opt_compact_summary(const struct option *opt,
+                                   const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_ARG(arg);
+       if (unset) {
+               options->flags.stat_with_summary = 0;
+       } else {
+               options->flags.stat_with_summary = 1;
+               options->output_format |= DIFF_FORMAT_DIFFSTAT;
+       }
+       return 0;
+}
+
+static int diff_opt_diff_algorithm(const struct option *opt,
+                                  const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+       long value = parse_algorithm_value(arg);
+
+       BUG_ON_OPT_NEG(unset);
+       if (value < 0)
+               return error(_("option diff-algorithm accepts \"myers\", "
+                              "\"minimal\", \"patience\" and \"histogram\""));
+
+       /* clear out previous settings */
+       DIFF_XDL_CLR(options, NEED_MINIMAL);
+       options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
+       options->xdl_opts |= value;
+       return 0;
+}
+
+static int diff_opt_dirstat(const struct option *opt,
+                           const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!strcmp(opt->long_name, "cumulative")) {
+               if (arg)
+                       BUG("how come --cumulative take a value?");
+               arg = "cumulative";
+       } else if (!strcmp(opt->long_name, "dirstat-by-file"))
+               parse_dirstat_opt(options, "files");
+       parse_dirstat_opt(options, arg ? arg : "");
+       return 0;
+}
+
+static int diff_opt_find_copies(const struct option *opt,
+                               const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "";
+       options->rename_score = parse_rename_score(&arg);
+       if (*arg != 0)
+               return error(_("invalid argument to %s"), opt->long_name);
+
+       if (options->detect_rename == DIFF_DETECT_COPY)
+               options->flags.find_copies_harder = 1;
+       else
+               options->detect_rename = DIFF_DETECT_COPY;
+
+       return 0;
+}
+
+static int diff_opt_find_renames(const struct option *opt,
+                                const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "";
+       options->rename_score = parse_rename_score(&arg);
+       if (*arg != 0)
+               return error(_("invalid argument to %s"), opt->long_name);
+
+       options->detect_rename = DIFF_DETECT_RENAME;
+       return 0;
+}
+
+static int diff_opt_follow(const struct option *opt,
+                          const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_ARG(arg);
+       if (unset) {
+               options->flags.follow_renames = 0;
+               options->flags.default_follow_renames = 0;
+       } else {
+               options->flags.follow_renames = 1;
+       }
+       return 0;
+}
+
+static int diff_opt_ignore_submodules(const struct option *opt,
+                                     const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "all";
+       options->flags.override_submodule_config = 1;
+       handle_ignore_submodules_arg(options, arg);
+       return 0;
+}
+
+static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
+                                            const struct option *opt,
+                                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+       char *path;
+
+       BUG_ON_OPT_NEG(unset);
+       path = prefix_filename(ctx->prefix, arg);
+       options->file = xfopen(path, "w");
+       options->close_file = 1;
+       if (options->use_color != GIT_COLOR_ALWAYS)
+               options->use_color = GIT_COLOR_NEVER;
+       free(path);
+       return 0;
+}
+
+static int diff_opt_patience(const struct option *opt,
+                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+       int i;
+
+       BUG_ON_OPT_NEG(unset);
+       BUG_ON_OPT_ARG(arg);
+       options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
+       /*
+        * Both --patience and --anchored use PATIENCE_DIFF
+        * internally, so remove any anchors previously
+        * specified.
+        */
+       for (i = 0; i < options->anchors_nr; i++)
+               free(options->anchors[i]);
+       options->anchors_nr = 0;
+       return 0;
+}
+
+static int diff_opt_relative(const struct option *opt,
+                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       options->flags.relative_name = 1;
+       if (arg)
+               options->prefix = arg;
+       return 0;
+}
+
+static int diff_opt_submodule(const struct option *opt,
+                             const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "log";
+       if (parse_submodule_params(options, arg))
+               return error(_("failed to parse --submodule option parameter: '%s'"),
+                            arg);
+       return 0;
+}
+
+static int diff_opt_textconv(const struct option *opt,
+                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_ARG(arg);
+       if (unset) {
+               options->flags.allow_textconv = 0;
+       } else {
+               options->flags.allow_textconv = 1;
+               options->flags.textconv_set_via_cmdline = 1;
+       }
+       return 0;
+}
+
 static int diff_opt_unified(const struct option *opt,
                            const char *arg, int unset)
 {
@@ -4949,6 +5179,44 @@ static int diff_opt_unified(const struct option *opt,
        return 0;
 }
 
+static int diff_opt_word_diff(const struct option *opt,
+                             const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (arg) {
+               if (!strcmp(arg, "plain"))
+                       options->word_diff = DIFF_WORDS_PLAIN;
+               else if (!strcmp(arg, "color")) {
+                       options->use_color = 1;
+                       options->word_diff = DIFF_WORDS_COLOR;
+               }
+               else if (!strcmp(arg, "porcelain"))
+                       options->word_diff = DIFF_WORDS_PORCELAIN;
+               else if (!strcmp(arg, "none"))
+                       options->word_diff = DIFF_WORDS_NONE;
+               else
+                       return error(_("bad --word-diff argument: %s"), arg);
+       } else {
+               if (options->word_diff == DIFF_WORDS_NONE)
+                       options->word_diff = DIFF_WORDS_PLAIN;
+       }
+       return 0;
+}
+
+static int diff_opt_word_diff_regex(const struct option *opt,
+                                   const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (options->word_diff == DIFF_WORDS_NONE)
+               options->word_diff = DIFF_WORDS_PLAIN;
+       options->word_regex = arg;
+       return 0;
+}
+
 static void prep_parse_options(struct diff_options *options)
 {
        struct option parseopts[] = {
@@ -4956,6 +5224,9 @@ static void prep_parse_options(struct diff_options *options)
                OPT_BITOP('p', "patch", &options->output_format,
                          N_("generate patch"),
                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
+               OPT_BIT_F('s', "no-patch", &options->output_format,
+                         N_("suppress diff output"),
+                         DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
                OPT_BITOP('u', NULL, &options->output_format,
                          N_("generate patch"),
                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
@@ -4967,6 +5238,187 @@ static void prep_parse_options(struct diff_options *options)
                OPT_BIT_F(0, "raw", &options->output_format,
                          N_("generate the diff in raw format"),
                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
+               OPT_BITOP(0, "patch-with-raw", &options->output_format,
+                         N_("synonym for '-p --raw'"),
+                         DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
+                         DIFF_FORMAT_NO_OUTPUT),
+               OPT_BITOP(0, "patch-with-stat", &options->output_format,
+                         N_("synonym for '-p --stat'"),
+                         DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
+                         DIFF_FORMAT_NO_OUTPUT),
+               OPT_BIT_F(0, "numstat", &options->output_format,
+                         N_("machine friendly --stat"),
+                         DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "shortstat", &options->output_format,
+                         N_("output only the last line of --stat"),
+                         DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
+               OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
+                              N_("output the distribution of relative amount of changes for each sub-directory"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_dirstat),
+               OPT_CALLBACK_F(0, "cumulative", options, NULL,
+                              N_("synonym for --dirstat=cumulative"),
+                              PARSE_OPT_NONEG | PARSE_OPT_NOARG,
+                              diff_opt_dirstat),
+               OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
+                              N_("synonym for --dirstat=files,param1,param2..."),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_dirstat),
+               OPT_BIT_F(0, "check", &options->output_format,
+                         N_("warn if changes introduce conflict markers or whitespace errors"),
+                         DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "summary", &options->output_format,
+                         N_("condensed summary such as creations, renames and mode changes"),
+                         DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "name-only", &options->output_format,
+                         N_("show only names of changed files"),
+                         DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "name-status", &options->output_format,
+                         N_("show only names and status of changed files"),
+                         DIFF_FORMAT_NAME_STATUS, PARSE_OPT_NONEG),
+               OPT_CALLBACK_F(0, "stat", options, N_("<width>[,<name-width>[,<count>]]"),
+                              N_("generate diffstat"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_stat),
+               OPT_CALLBACK_F(0, "stat-width", options, N_("<width>"),
+                              N_("generate diffstat with a given width"),
+                              PARSE_OPT_NONEG, diff_opt_stat),
+               OPT_CALLBACK_F(0, "stat-name-width", options, N_("<width>"),
+                              N_("generate diffstat with a given name width"),
+                              PARSE_OPT_NONEG, diff_opt_stat),
+               OPT_CALLBACK_F(0, "stat-graph-width", options, N_("<width>"),
+                              N_("generate diffstat with a given graph width"),
+                              PARSE_OPT_NONEG, diff_opt_stat),
+               OPT_CALLBACK_F(0, "stat-count", options, N_("<count>"),
+                              N_("generate diffstat with limited lines"),
+                              PARSE_OPT_NONEG, diff_opt_stat),
+               OPT_CALLBACK_F(0, "compact-summary", options, NULL,
+                              N_("generate compact summary in diffstat"),
+                              PARSE_OPT_NOARG, diff_opt_compact_summary),
+               OPT_CALLBACK_F(0, "binary", options, NULL,
+                              N_("output a binary diff that can be applied"),
+                              PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_binary),
+               OPT_BOOL(0, "full-index", &options->flags.full_index,
+                        N_("show full pre- and post-image object names on the \"index\" lines")),
+               OPT_COLOR_FLAG(0, "color", &options->use_color,
+                              N_("show colored diff")),
+               OPT_CALLBACK_F(0, "output-indicator-new",
+                              &options->output_indicators[OUTPUT_INDICATOR_NEW],
+                              N_("<char>"),
+                              N_("specify the character to indicate a new line instead of '+'"),
+                              PARSE_OPT_NONEG, diff_opt_char),
+               OPT_CALLBACK_F(0, "output-indicator-old",
+                              &options->output_indicators[OUTPUT_INDICATOR_OLD],
+                              N_("<char>"),
+                              N_("specify the character to indicate an old line instead of '-'"),
+                              PARSE_OPT_NONEG, diff_opt_char),
+               OPT_CALLBACK_F(0, "output-indicator-context",
+                              &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
+                              N_("<char>"),
+                              N_("specify the character to indicate a context instead of ' '"),
+                              PARSE_OPT_NONEG, diff_opt_char),
+
+               OPT_GROUP(N_("Diff rename options")),
+               OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
+                              N_("break complete rewrite changes into pairs of delete and create"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_break_rewrites),
+               OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
+                              N_("detect renames"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_find_renames),
+               OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
+                             N_("omit the preimage for deletes"),
+                             1, PARSE_OPT_NONEG),
+               OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
+                              N_("detect copies"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_find_copies),
+               OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
+                        N_("use unmodified files as source to find copies")),
+               OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
+                             N_("disable rename detection"),
+                             0, PARSE_OPT_NONEG),
+               OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
+                        N_("use empty blobs as rename source")),
+               OPT_CALLBACK_F(0, "follow", options, NULL,
+                              N_("continue listing the history of a file beyond renames"),
+                              PARSE_OPT_NOARG, diff_opt_follow),
+
+               OPT_GROUP(N_("Diff algorithm options")),
+               OPT_BIT(0, "minimal", &options->xdl_opts,
+                       N_("produce the smallest possible diff"),
+                       XDF_NEED_MINIMAL),
+               OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
+                         N_("ignore whitespace when comparing lines"),
+                         XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
+               OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
+                         N_("ignore changes in amount of whitespace"),
+                         XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
+                         N_("ignore changes in whitespace at EOL"),
+                         XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
+                         N_("ignore carrier-return at the end of line"),
+                         XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
+                         N_("ignore changes whose lines are all blank"),
+                         XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
+               OPT_BIT(0, "indent-heuristic", &options->xdl_opts,
+                       N_("heuristic to shift diff hunk boundaries for easy reading"),
+                       XDF_INDENT_HEURISTIC),
+               OPT_CALLBACK_F(0, "patience", options, NULL,
+                              N_("generate diff using the \"patience diff\" algorithm"),
+                              PARSE_OPT_NONEG | PARSE_OPT_NOARG,
+                              diff_opt_patience),
+               OPT_BITOP(0, "histogram", &options->xdl_opts,
+                         N_("generate diff using the \"histogram diff\" algorithm"),
+                         XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
+               OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
+                              N_("choose a diff algorithm"),
+                              PARSE_OPT_NONEG, diff_opt_diff_algorithm),
+               OPT_CALLBACK_F(0, "anchored", options, N_("<text>"),
+                              N_("generate diff using the \"anchored diff\" algorithm"),
+                              PARSE_OPT_NONEG, diff_opt_anchored),
+               OPT_CALLBACK_F(0, "word-diff", options, N_("<mode>"),
+                              N_("show word diff, using <mode> to delimit changed words"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_word_diff),
+               OPT_CALLBACK_F(0, "word-diff-regex", options, N_("<regex>"),
+                              N_("use <regex> to decide what a word is"),
+                              PARSE_OPT_NONEG, diff_opt_word_diff_regex),
+               OPT_CALLBACK_F(0, "color-words", options, N_("<regex>"),
+                              N_("equivalent to --word-diff=color --word-diff-regex=<regex>"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_color_words),
+
+               OPT_GROUP(N_("Diff other options")),
+               OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
+                              N_("when run from subdir, exclude changes outside and show relative paths"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_relative),
+               OPT_BOOL('a', "text", &options->flags.text,
+                        N_("treat all files as text")),
+               OPT_BOOL('R', NULL, &options->flags.reverse_diff,
+                        N_("swap two inputs, reverse the diff")),
+               OPT_BOOL(0, "exit-code", &options->flags.exit_with_status,
+                        N_("exit with 1 if there were differences, 0 otherwise")),
+               OPT_BOOL(0, "quiet", &options->flags.quick,
+                        N_("disable all output of the program")),
+               OPT_BOOL(0, "ext-diff", &options->flags.allow_external,
+                        N_("allow an external diff helper to be executed")),
+               OPT_CALLBACK_F(0, "textconv", options, NULL,
+                              N_("run external text conversion filters when comparing binary files"),
+                              PARSE_OPT_NOARG, diff_opt_textconv),
+               OPT_CALLBACK_F(0, "ignore-submodules", options, N_("<when>"),
+                              N_("ignore changes to submodules in the diff generation"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_ignore_submodules),
+               OPT_CALLBACK_F(0, "submodule", options, N_("<format>"),
+                              N_("specify how differences in submodules are shown"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_submodule),
+               { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
+                 N_("Output to a specific file"),
+                 PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
+
                OPT_END()
        };
 
@@ -4994,162 +5446,8 @@ int diff_opt_parse(struct diff_options *options,
        if (ac)
                return ac;
 
-       /* Output format options */
-       if (!strcmp(arg, "--patch-with-raw")) {
-               enable_patch_output(&options->output_format);
-               options->output_format |= DIFF_FORMAT_RAW;
-       } else if (!strcmp(arg, "--numstat"))
-               options->output_format |= DIFF_FORMAT_NUMSTAT;
-       else if (!strcmp(arg, "--shortstat"))
-               options->output_format |= DIFF_FORMAT_SHORTSTAT;
-       else if (skip_prefix(arg, "-X", &arg) ||
-                skip_to_optional_arg(arg, "--dirstat", &arg))
-               return parse_dirstat_opt(options, arg);
-       else if (!strcmp(arg, "--cumulative"))
-               return parse_dirstat_opt(options, "cumulative");
-       else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
-               parse_dirstat_opt(options, "files");
-               return parse_dirstat_opt(options, arg);
-       }
-       else if (!strcmp(arg, "--check"))
-               options->output_format |= DIFF_FORMAT_CHECKDIFF;
-       else if (!strcmp(arg, "--summary"))
-               options->output_format |= DIFF_FORMAT_SUMMARY;
-       else if (!strcmp(arg, "--patch-with-stat")) {
-               enable_patch_output(&options->output_format);
-               options->output_format |= DIFF_FORMAT_DIFFSTAT;
-       } else if (!strcmp(arg, "--name-only"))
-               options->output_format |= DIFF_FORMAT_NAME;
-       else if (!strcmp(arg, "--name-status"))
-               options->output_format |= DIFF_FORMAT_NAME_STATUS;
-       else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
-               options->output_format |= DIFF_FORMAT_NO_OUTPUT;
-       else if (starts_with(arg, "--stat"))
-               /* --stat, --stat-width, --stat-name-width, or --stat-count */
-               return stat_opt(options, av);
-       else if (!strcmp(arg, "--compact-summary")) {
-                options->flags.stat_with_summary = 1;
-                options->output_format |= DIFF_FORMAT_DIFFSTAT;
-       } else if (!strcmp(arg, "--no-compact-summary"))
-                options->flags.stat_with_summary = 0;
-       else if (skip_prefix(arg, "--output-indicator-new=", &arg))
-               options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
-       else if (skip_prefix(arg, "--output-indicator-old=", &arg))
-               options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
-       else if (skip_prefix(arg, "--output-indicator-context=", &arg))
-               options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
-
-       /* renames options */
-       else if (starts_with(arg, "-B") ||
-                skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
-               if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
-                       return error("invalid argument to -B: %s", arg+2);
-       }
-       else if (starts_with(arg, "-M") ||
-                skip_to_optional_arg(arg, "--find-renames", NULL)) {
-               if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
-                       return error("invalid argument to -M: %s", arg+2);
-               options->detect_rename = DIFF_DETECT_RENAME;
-       }
-       else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
-               options->irreversible_delete = 1;
-       }
-       else if (starts_with(arg, "-C") ||
-                skip_to_optional_arg(arg, "--find-copies", NULL)) {
-               if (options->detect_rename == DIFF_DETECT_COPY)
-                       options->flags.find_copies_harder = 1;
-               if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
-                       return error("invalid argument to -C: %s", arg+2);
-               options->detect_rename = DIFF_DETECT_COPY;
-       }
-       else if (!strcmp(arg, "--no-renames"))
-               options->detect_rename = 0;
-       else if (!strcmp(arg, "--rename-empty"))
-               options->flags.rename_empty = 1;
-       else if (!strcmp(arg, "--no-rename-empty"))
-               options->flags.rename_empty = 0;
-       else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
-               options->flags.relative_name = 1;
-               if (arg)
-                       options->prefix = arg;
-       }
-
-       /* xdiff options */
-       else if (!strcmp(arg, "--minimal"))
-               DIFF_XDL_SET(options, NEED_MINIMAL);
-       else if (!strcmp(arg, "--no-minimal"))
-               DIFF_XDL_CLR(options, NEED_MINIMAL);
-       else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
-               DIFF_XDL_SET(options, IGNORE_WHITESPACE);
-       else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
-               DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
-       else if (!strcmp(arg, "--ignore-space-at-eol"))
-               DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
-       else if (!strcmp(arg, "--ignore-cr-at-eol"))
-               DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
-       else if (!strcmp(arg, "--ignore-blank-lines"))
-               DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
-       else if (!strcmp(arg, "--indent-heuristic"))
-               DIFF_XDL_SET(options, INDENT_HEURISTIC);
-       else if (!strcmp(arg, "--no-indent-heuristic"))
-               DIFF_XDL_CLR(options, INDENT_HEURISTIC);
-       else if (!strcmp(arg, "--patience")) {
-               int i;
-               options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
-               /*
-                * Both --patience and --anchored use PATIENCE_DIFF
-                * internally, so remove any anchors previously
-                * specified.
-                */
-               for (i = 0; i < options->anchors_nr; i++)
-                       free(options->anchors[i]);
-               options->anchors_nr = 0;
-       } else if (!strcmp(arg, "--histogram"))
-               options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
-       else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
-               long value = parse_algorithm_value(optarg);
-               if (value < 0)
-                       return error("option diff-algorithm accepts \"myers\", "
-                                    "\"minimal\", \"patience\" and \"histogram\"");
-               /* clear out previous settings */
-               DIFF_XDL_CLR(options, NEED_MINIMAL);
-               options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
-               options->xdl_opts |= value;
-               return argcount;
-       } else if (skip_prefix(arg, "--anchored=", &arg)) {
-               options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
-               ALLOC_GROW(options->anchors, options->anchors_nr + 1,
-                          options->anchors_alloc);
-               options->anchors[options->anchors_nr++] = xstrdup(arg);
-       }
-
        /* flags options */
-       else if (!strcmp(arg, "--binary")) {
-               enable_patch_output(&options->output_format);
-               options->flags.binary = 1;
-       }
-       else if (!strcmp(arg, "--full-index"))
-               options->flags.full_index = 1;
-       else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
-               options->flags.text = 1;
-       else if (!strcmp(arg, "-R"))
-               options->flags.reverse_diff = 1;
-       else if (!strcmp(arg, "--find-copies-harder"))
-               options->flags.find_copies_harder = 1;
-       else if (!strcmp(arg, "--follow"))
-               options->flags.follow_renames = 1;
-       else if (!strcmp(arg, "--no-follow")) {
-               options->flags.follow_renames = 0;
-               options->flags.default_follow_renames = 0;
-       } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
-               int value = git_config_colorbool(NULL, arg);
-               if (value < 0)
-                       return error("option `color' expects \"always\", \"auto\", or \"never\"");
-               options->use_color = value;
-       }
-       else if (!strcmp(arg, "--no-color"))
-               options->use_color = 0;
-       else if (!strcmp(arg, "--color-moved")) {
+       if (!strcmp(arg, "--color-moved")) {
                if (diff_color_moved_default)
                        options->color_moved = diff_color_moved_default;
                if (options->color_moved == COLOR_MOVED_NO)
@@ -5168,53 +5466,7 @@ int diff_opt_parse(struct diff_options *options,
                if (cm & COLOR_MOVED_WS_ERROR)
                        return -1;
                options->color_moved_ws_handling = cm;
-       } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
-               options->use_color = 1;
-               options->word_diff = DIFF_WORDS_COLOR;
-       }
-       else if (!strcmp(arg, "--word-diff")) {
-               if (options->word_diff == DIFF_WORDS_NONE)
-                       options->word_diff = DIFF_WORDS_PLAIN;
-       }
-       else if (skip_prefix(arg, "--word-diff=", &arg)) {
-               if (!strcmp(arg, "plain"))
-                       options->word_diff = DIFF_WORDS_PLAIN;
-               else if (!strcmp(arg, "color")) {
-                       options->use_color = 1;
-                       options->word_diff = DIFF_WORDS_COLOR;
-               }
-               else if (!strcmp(arg, "porcelain"))
-                       options->word_diff = DIFF_WORDS_PORCELAIN;
-               else if (!strcmp(arg, "none"))
-                       options->word_diff = DIFF_WORDS_NONE;
-               else
-                       die("bad --word-diff argument: %s", arg);
-       }
-       else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
-               if (options->word_diff == DIFF_WORDS_NONE)
-                       options->word_diff = DIFF_WORDS_PLAIN;
-               options->word_regex = optarg;
-               return argcount;
-       }
-       else if (!strcmp(arg, "--exit-code"))
-               options->flags.exit_with_status = 1;
-       else if (!strcmp(arg, "--quiet"))
-               options->flags.quick = 1;
-       else if (!strcmp(arg, "--ext-diff"))
-               options->flags.allow_external = 1;
-       else if (!strcmp(arg, "--no-ext-diff"))
-               options->flags.allow_external = 0;
-       else if (!strcmp(arg, "--textconv")) {
-               options->flags.allow_textconv = 1;
-               options->flags.textconv_set_via_cmdline = 1;
-       } else if (!strcmp(arg, "--no-textconv"))
-               options->flags.allow_textconv = 0;
-       else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
-               options->flags.override_submodule_config = 1;
-               handle_ignore_submodules_arg(options, arg);
-       } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
-               return parse_submodule_opt(options, arg);
-       else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
+       } else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
                return parse_ws_error_highlight_opt(options, arg);
        else if (!strcmp(arg, "--ita-invisible-in-index"))
                options->ita_invisible_in_index = 1;
@@ -5283,15 +5535,7 @@ int diff_opt_parse(struct diff_options *options,
        else if (opt_arg(arg, '\0', "inter-hunk-context",
                         &options->interhunkcontext))
                ;
-       else if ((argcount = parse_long_opt("output", av, &optarg))) {
-               char *path = prefix_filename(prefix, optarg);
-               options->file = xfopen(path, "w");
-               options->close_file = 1;
-               if (options->use_color != GIT_COLOR_ALWAYS)
-                       options->use_color = GIT_COLOR_NEVER;
-               free(path);
-               return argcount;
-       } else
+       else
                return 0;
        return 1;
 }
@@ -5332,47 +5576,6 @@ int parse_rename_score(const char **cp_p)
        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
 }
 
-static int diff_scoreopt_parse(const char *opt)
-{
-       int opt1, opt2, cmd;
-
-       if (*opt++ != '-')
-               return -1;
-       cmd = *opt++;
-       if (cmd == '-') {
-               /* convert the long-form arguments into short-form versions */
-               if (skip_prefix(opt, "break-rewrites", &opt)) {
-                       if (*opt == 0 || *opt++ == '=')
-                               cmd = 'B';
-               } else if (skip_prefix(opt, "find-copies", &opt)) {
-                       if (*opt == 0 || *opt++ == '=')
-                               cmd = 'C';
-               } else if (skip_prefix(opt, "find-renames", &opt)) {
-                       if (*opt == 0 || *opt++ == '=')
-                               cmd = 'M';
-               }
-       }
-       if (cmd != 'M' && cmd != 'C' && cmd != 'B')
-               return -1; /* that is not a -M, -C, or -B option */
-
-       opt1 = parse_rename_score(&opt);
-       if (cmd != 'B')
-               opt2 = 0;
-       else {
-               if (*opt == 0)
-                       opt2 = 0;
-               else if (*opt != '/')
-                       return -1; /* we expect -B80/99 or -B80 */
-               else {
-                       opt++;
-                       opt2 = parse_rename_score(&opt);
-               }
-       }
-       if (*opt != 0)
-               return -1;
-       return opt1 | (opt2 << 16);
-}
-
 struct diff_queue_struct diff_queued_diff;
 
 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
@@ -6271,7 +6474,7 @@ static int diffnamecmp(const void *a_, const void *b_)
        return strcmp(name_a, name_b);
 }
 
-void diffcore_fix_diff_index(struct diff_options *options)
+void diffcore_fix_diff_index(void)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        QSORT(q->queue, q->nr, diffnamecmp);