Merge branch 'js/reset'
[git] / parse-options.c
1 #include "git-compat-util.h"
2 #include "parse-options.h"
3
4 #define OPT_SHORT 1
5 #define OPT_UNSET 2
6
7 struct optparse_t {
8         const char **argv;
9         int argc;
10         const char *opt;
11 };
12
13 static inline const char *get_arg(struct optparse_t *p)
14 {
15         if (p->opt) {
16                 const char *res = p->opt;
17                 p->opt = NULL;
18                 return res;
19         }
20         p->argc--;
21         return *++p->argv;
22 }
23
24 static inline const char *skip_prefix(const char *str, const char *prefix)
25 {
26         size_t len = strlen(prefix);
27         return strncmp(str, prefix, len) ? NULL : str + len;
28 }
29
30 static int opterror(const struct option *opt, const char *reason, int flags)
31 {
32         if (flags & OPT_SHORT)
33                 return error("switch `%c' %s", opt->short_name, reason);
34         if (flags & OPT_UNSET)
35                 return error("option `no-%s' %s", opt->long_name, reason);
36         return error("option `%s' %s", opt->long_name, reason);
37 }
38
39 static int get_value(struct optparse_t *p,
40                      const struct option *opt, int flags)
41 {
42         const char *s, *arg;
43         arg = p->opt ? p->opt : (p->argc > 1 ? p->argv[1] : NULL);
44
45         if (p->opt && (flags & OPT_UNSET))
46                 return opterror(opt, "takes no value", flags);
47
48         switch (opt->type) {
49         case OPTION_BOOLEAN:
50                 if (!(flags & OPT_SHORT) && p->opt)
51                         return opterror(opt, "takes no value", flags);
52                 if (flags & OPT_UNSET)
53                         *(int *)opt->value = 0;
54                 else
55                         (*(int *)opt->value)++;
56                 return 0;
57
58         case OPTION_STRING:
59                 if (flags & OPT_UNSET) {
60                         *(const char **)opt->value = (const char *)NULL;
61                         return 0;
62                 }
63                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-')) {
64                         *(const char **)opt->value = (const char *)opt->defval;
65                         return 0;
66                 }
67                 if (!arg)
68                         return opterror(opt, "requires a value", flags);
69                 *(const char **)opt->value = get_arg(p);
70                 return 0;
71
72         case OPTION_CALLBACK:
73                 if (flags & OPT_UNSET)
74                         return (*opt->callback)(opt, NULL, 1);
75                 if (opt->flags & PARSE_OPT_NOARG) {
76                         if (p->opt && !(flags & OPT_SHORT))
77                                 return opterror(opt, "takes no value", flags);
78                         return (*opt->callback)(opt, NULL, 0);
79                 }
80                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-'))
81                         return (*opt->callback)(opt, NULL, 0);
82                 if (!arg)
83                         return opterror(opt, "requires a value", flags);
84                 return (*opt->callback)(opt, get_arg(p), 0);
85
86         case OPTION_INTEGER:
87                 if (flags & OPT_UNSET) {
88                         *(int *)opt->value = 0;
89                         return 0;
90                 }
91                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || !isdigit(*arg))) {
92                         *(int *)opt->value = opt->defval;
93                         return 0;
94                 }
95                 if (!arg)
96                         return opterror(opt, "requires a value", flags);
97                 *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
98                 if (*s)
99                         return opterror(opt, "expects a numerical value", flags);
100                 return 0;
101
102         default:
103                 die("should not happen, someone must be hit on the forehead");
104         }
105 }
106
107 static int parse_short_opt(struct optparse_t *p, const struct option *options)
108 {
109         for (; options->type != OPTION_END; options++) {
110                 if (options->short_name == *p->opt) {
111                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
112                         return get_value(p, options, OPT_SHORT);
113                 }
114         }
115         return error("unknown switch `%c'", *p->opt);
116 }
117
118 static int parse_long_opt(struct optparse_t *p, const char *arg,
119                           const struct option *options)
120 {
121         const char *arg_end = strchr(arg, '=');
122         const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
123         int abbrev_flags = 0, ambiguous_flags = 0;
124
125         if (!arg_end)
126                 arg_end = arg + strlen(arg);
127
128         for (; options->type != OPTION_END; options++) {
129                 const char *rest;
130                 int flags = 0;
131
132                 if (!options->long_name)
133                         continue;
134
135                 rest = skip_prefix(arg, options->long_name);
136                 if (!rest) {
137                         /* abbreviated? */
138                         if (!strncmp(options->long_name, arg, arg_end - arg)) {
139 is_abbreviated:
140                                 if (abbrev_option) {
141                                         /*
142                                          * If this is abbreviated, it is
143                                          * ambiguous. So when there is no
144                                          * exact match later, we need to
145                                          * error out.
146                                          */
147                                         ambiguous_option = abbrev_option;
148                                         ambiguous_flags = abbrev_flags;
149                                 }
150                                 if (!(flags & OPT_UNSET) && *arg_end)
151                                         p->opt = arg_end + 1;
152                                 abbrev_option = options;
153                                 abbrev_flags = flags;
154                                 continue;
155                         }
156                         /* negated and abbreviated very much? */
157                         if (!prefixcmp("no-", arg)) {
158                                 flags |= OPT_UNSET;
159                                 goto is_abbreviated;
160                         }
161                         /* negated? */
162                         if (strncmp(arg, "no-", 3))
163                                 continue;
164                         flags |= OPT_UNSET;
165                         rest = skip_prefix(arg + 3, options->long_name);
166                         /* abbreviated and negated? */
167                         if (!rest && !prefixcmp(options->long_name, arg + 3))
168                                 goto is_abbreviated;
169                         if (!rest)
170                                 continue;
171                 }
172                 if (*rest) {
173                         if (*rest != '=')
174                                 continue;
175                         p->opt = rest + 1;
176                 }
177                 return get_value(p, options, flags);
178         }
179
180         if (ambiguous_option)
181                 return error("Ambiguous option: %s "
182                         "(could be --%s%s or --%s%s)",
183                         arg,
184                         (ambiguous_flags & OPT_UNSET) ?  "no-" : "",
185                         ambiguous_option->long_name,
186                         (abbrev_flags & OPT_UNSET) ?  "no-" : "",
187                         abbrev_option->long_name);
188         if (abbrev_option)
189                 return get_value(p, abbrev_option, abbrev_flags);
190         return error("unknown option `%s'", arg);
191 }
192
193 int parse_options(int argc, const char **argv, const struct option *options,
194                   const char * const usagestr[], int flags)
195 {
196         struct optparse_t args = { argv + 1, argc - 1, NULL };
197         int j = 0;
198
199         for (; args.argc; args.argc--, args.argv++) {
200                 const char *arg = args.argv[0];
201
202                 if (*arg != '-' || !arg[1]) {
203                         argv[j++] = args.argv[0];
204                         continue;
205                 }
206
207                 if (arg[1] != '-') {
208                         args.opt = arg + 1;
209                         do {
210                                 if (*args.opt == 'h')
211                                         usage_with_options(usagestr, options);
212                                 if (parse_short_opt(&args, options) < 0)
213                                         usage_with_options(usagestr, options);
214                         } while (args.opt);
215                         continue;
216                 }
217
218                 if (!arg[2]) { /* "--" */
219                         if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
220                                 args.argc--;
221                                 args.argv++;
222                         }
223                         break;
224                 }
225
226                 if (!strcmp(arg + 2, "help"))
227                         usage_with_options(usagestr, options);
228                 if (parse_long_opt(&args, arg + 2, options))
229                         usage_with_options(usagestr, options);
230         }
231
232         memmove(argv + j, args.argv, args.argc * sizeof(*argv));
233         argv[j + args.argc] = NULL;
234         return j + args.argc;
235 }
236
237 #define USAGE_OPTS_WIDTH 24
238 #define USAGE_GAP         2
239
240 void usage_with_options(const char * const *usagestr,
241                         const struct option *opts)
242 {
243         fprintf(stderr, "usage: %s\n", *usagestr++);
244         while (*usagestr && **usagestr)
245                 fprintf(stderr, "   or: %s\n", *usagestr++);
246         while (*usagestr)
247                 fprintf(stderr, "    %s\n", *usagestr++);
248
249         if (opts->type != OPTION_GROUP)
250                 fputc('\n', stderr);
251
252         for (; opts->type != OPTION_END; opts++) {
253                 size_t pos;
254                 int pad;
255
256                 if (opts->type == OPTION_GROUP) {
257                         fputc('\n', stderr);
258                         if (*opts->help)
259                                 fprintf(stderr, "%s\n", opts->help);
260                         continue;
261                 }
262
263                 pos = fprintf(stderr, "    ");
264                 if (opts->short_name)
265                         pos += fprintf(stderr, "-%c", opts->short_name);
266                 if (opts->long_name && opts->short_name)
267                         pos += fprintf(stderr, ", ");
268                 if (opts->long_name)
269                         pos += fprintf(stderr, "--%s", opts->long_name);
270
271                 switch (opts->type) {
272                 case OPTION_INTEGER:
273                         if (opts->flags & PARSE_OPT_OPTARG)
274                                 pos += fprintf(stderr, " [<n>]");
275                         else
276                                 pos += fprintf(stderr, " <n>");
277                         break;
278                 case OPTION_CALLBACK:
279                         if (opts->flags & PARSE_OPT_NOARG)
280                                 break;
281                         /* FALLTHROUGH */
282                 case OPTION_STRING:
283                         if (opts->argh) {
284                                 if (opts->flags & PARSE_OPT_OPTARG)
285                                         pos += fprintf(stderr, " [<%s>]", opts->argh);
286                                 else
287                                         pos += fprintf(stderr, " <%s>", opts->argh);
288                         } else {
289                                 if (opts->flags & PARSE_OPT_OPTARG)
290                                         pos += fprintf(stderr, " [...]");
291                                 else
292                                         pos += fprintf(stderr, " ...");
293                         }
294                         break;
295                 default:
296                         break;
297                 }
298
299                 if (pos <= USAGE_OPTS_WIDTH)
300                         pad = USAGE_OPTS_WIDTH - pos;
301                 else {
302                         fputc('\n', stderr);
303                         pad = USAGE_OPTS_WIDTH;
304                 }
305                 fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
306         }
307         fputc('\n', stderr);
308
309         exit(129);
310 }
311
312 /*----- some often used options -----*/
313 #include "cache.h"
314 int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
315 {
316         int v;
317
318         if (!arg) {
319                 v = unset ? 0 : DEFAULT_ABBREV;
320         } else {
321                 v = strtol(arg, (char **)&arg, 10);
322                 if (*arg)
323                         return opterror(opt, "expects a numerical value", 0);
324                 if (v && v < MINIMUM_ABBREV)
325                         v = MINIMUM_ABBREV;
326                 else if (v > 40)
327                         v = 40;
328         }
329         *(int *)(opt->value) = v;
330         return 0;
331 }