parse-opt: Export a non NORETURN usage dumper.
[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 static inline const char *get_arg(struct parse_opt_ctx_t *p)
8 {
9         if (p->opt) {
10                 const char *res = p->opt;
11                 p->opt = NULL;
12                 return res;
13         }
14         p->argc--;
15         return *++p->argv;
16 }
17
18 static inline const char *skip_prefix(const char *str, const char *prefix)
19 {
20         size_t len = strlen(prefix);
21         return strncmp(str, prefix, len) ? NULL : str + len;
22 }
23
24 static int opterror(const struct option *opt, const char *reason, int flags)
25 {
26         if (flags & OPT_SHORT)
27                 return error("switch `%c' %s", opt->short_name, reason);
28         if (flags & OPT_UNSET)
29                 return error("option `no-%s' %s", opt->long_name, reason);
30         return error("option `%s' %s", opt->long_name, reason);
31 }
32
33 static int get_value(struct parse_opt_ctx_t *p,
34                      const struct option *opt, int flags)
35 {
36         const char *s, *arg;
37         const int unset = flags & OPT_UNSET;
38
39         if (unset && p->opt)
40                 return opterror(opt, "takes no value", flags);
41         if (unset && (opt->flags & PARSE_OPT_NONEG))
42                 return opterror(opt, "isn't available", flags);
43
44         if (!(flags & OPT_SHORT) && p->opt) {
45                 switch (opt->type) {
46                 case OPTION_CALLBACK:
47                         if (!(opt->flags & PARSE_OPT_NOARG))
48                                 break;
49                         /* FALLTHROUGH */
50                 case OPTION_BOOLEAN:
51                 case OPTION_BIT:
52                 case OPTION_SET_INT:
53                 case OPTION_SET_PTR:
54                         return opterror(opt, "takes no value", flags);
55                 default:
56                         break;
57                 }
58         }
59
60         arg = p->opt ? p->opt : (p->argc > 1 ? p->argv[1] : NULL);
61         switch (opt->type) {
62         case OPTION_BIT:
63                 if (unset)
64                         *(int *)opt->value &= ~opt->defval;
65                 else
66                         *(int *)opt->value |= opt->defval;
67                 return 0;
68
69         case OPTION_BOOLEAN:
70                 *(int *)opt->value = unset ? 0 : *(int *)opt->value + 1;
71                 return 0;
72
73         case OPTION_SET_INT:
74                 *(int *)opt->value = unset ? 0 : opt->defval;
75                 return 0;
76
77         case OPTION_SET_PTR:
78                 *(void **)opt->value = unset ? NULL : (void *)opt->defval;
79                 return 0;
80
81         case OPTION_STRING:
82                 if (unset) {
83                         *(const char **)opt->value = NULL;
84                         return 0;
85                 }
86                 if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
87                         *(const char **)opt->value = (const char *)opt->defval;
88                         return 0;
89                 }
90                 if (!arg)
91                         return opterror(opt, "requires a value", flags);
92                 *(const char **)opt->value = get_arg(p);
93                 return 0;
94
95         case OPTION_CALLBACK:
96                 if (unset)
97                         return (*opt->callback)(opt, NULL, 1);
98                 if (opt->flags & PARSE_OPT_NOARG)
99                         return (*opt->callback)(opt, NULL, 0);
100                 if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
101                         return (*opt->callback)(opt, NULL, 0);
102                 if (!arg)
103                         return opterror(opt, "requires a value", flags);
104                 return (*opt->callback)(opt, get_arg(p), 0);
105
106         case OPTION_INTEGER:
107                 if (unset) {
108                         *(int *)opt->value = 0;
109                         return 0;
110                 }
111                 if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
112                         *(int *)opt->value = opt->defval;
113                         return 0;
114                 }
115                 if (!arg)
116                         return opterror(opt, "requires a value", flags);
117                 *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
118                 if (*s)
119                         return opterror(opt, "expects a numerical value", flags);
120                 return 0;
121
122         default:
123                 die("should not happen, someone must be hit on the forehead");
124         }
125 }
126
127 static int parse_short_opt(struct parse_opt_ctx_t *p, const struct option *options)
128 {
129         for (; options->type != OPTION_END; options++) {
130                 if (options->short_name == *p->opt) {
131                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
132                         return get_value(p, options, OPT_SHORT);
133                 }
134         }
135         return error("unknown switch `%c'", *p->opt);
136 }
137
138 static int parse_long_opt(struct parse_opt_ctx_t *p, const char *arg,
139                           const struct option *options)
140 {
141         const char *arg_end = strchr(arg, '=');
142         const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
143         int abbrev_flags = 0, ambiguous_flags = 0;
144
145         if (!arg_end)
146                 arg_end = arg + strlen(arg);
147
148         for (; options->type != OPTION_END; options++) {
149                 const char *rest;
150                 int flags = 0;
151
152                 if (!options->long_name)
153                         continue;
154
155                 rest = skip_prefix(arg, options->long_name);
156                 if (options->type == OPTION_ARGUMENT) {
157                         if (!rest)
158                                 continue;
159                         if (*rest == '=')
160                                 return opterror(options, "takes no value", flags);
161                         if (*rest)
162                                 continue;
163                         p->out[p->cpidx++] = arg - 2;
164                         return 0;
165                 }
166                 if (!rest) {
167                         /* abbreviated? */
168                         if (!strncmp(options->long_name, arg, arg_end - arg)) {
169 is_abbreviated:
170                                 if (abbrev_option) {
171                                         /*
172                                          * If this is abbreviated, it is
173                                          * ambiguous. So when there is no
174                                          * exact match later, we need to
175                                          * error out.
176                                          */
177                                         ambiguous_option = abbrev_option;
178                                         ambiguous_flags = abbrev_flags;
179                                 }
180                                 if (!(flags & OPT_UNSET) && *arg_end)
181                                         p->opt = arg_end + 1;
182                                 abbrev_option = options;
183                                 abbrev_flags = flags;
184                                 continue;
185                         }
186                         /* negated and abbreviated very much? */
187                         if (!prefixcmp("no-", arg)) {
188                                 flags |= OPT_UNSET;
189                                 goto is_abbreviated;
190                         }
191                         /* negated? */
192                         if (strncmp(arg, "no-", 3))
193                                 continue;
194                         flags |= OPT_UNSET;
195                         rest = skip_prefix(arg + 3, options->long_name);
196                         /* abbreviated and negated? */
197                         if (!rest && !prefixcmp(options->long_name, arg + 3))
198                                 goto is_abbreviated;
199                         if (!rest)
200                                 continue;
201                 }
202                 if (*rest) {
203                         if (*rest != '=')
204                                 continue;
205                         p->opt = rest + 1;
206                 }
207                 return get_value(p, options, flags);
208         }
209
210         if (ambiguous_option)
211                 return error("Ambiguous option: %s "
212                         "(could be --%s%s or --%s%s)",
213                         arg,
214                         (ambiguous_flags & OPT_UNSET) ?  "no-" : "",
215                         ambiguous_option->long_name,
216                         (abbrev_flags & OPT_UNSET) ?  "no-" : "",
217                         abbrev_option->long_name);
218         if (abbrev_option)
219                 return get_value(p, abbrev_option, abbrev_flags);
220         return error("unknown option `%s'", arg);
221 }
222
223 void check_typos(const char *arg, const struct option *options)
224 {
225         if (strlen(arg) < 3)
226                 return;
227
228         if (!prefixcmp(arg, "no-")) {
229                 error ("did you mean `--%s` (with two dashes ?)", arg);
230                 exit(129);
231         }
232
233         for (; options->type != OPTION_END; options++) {
234                 if (!options->long_name)
235                         continue;
236                 if (!prefixcmp(options->long_name, arg)) {
237                         error ("did you mean `--%s` (with two dashes ?)", arg);
238                         exit(129);
239                 }
240         }
241 }
242
243 void parse_options_start(struct parse_opt_ctx_t *ctx,
244                          int argc, const char **argv, int flags)
245 {
246         memset(ctx, 0, sizeof(*ctx));
247         ctx->argc = argc - 1;
248         ctx->argv = argv + 1;
249         ctx->out  = argv;
250         ctx->flags = flags;
251 }
252
253 int parse_options_end(struct parse_opt_ctx_t *ctx)
254 {
255         memmove(ctx->out + ctx->cpidx, ctx->argv, ctx->argc * sizeof(*ctx->out));
256         ctx->out[ctx->cpidx + ctx->argc] = NULL;
257         return ctx->cpidx + ctx->argc;
258 }
259
260 static int usage_with_options_internal(const char * const *,
261                                        const struct option *, int, int);
262
263 int parse_options(int argc, const char **argv, const struct option *options,
264                   const char * const usagestr[], int flags)
265 {
266         struct parse_opt_ctx_t ctx;
267
268         parse_options_start(&ctx, argc, argv, flags);
269         for (; ctx.argc; ctx.argc--, ctx.argv++) {
270                 const char *arg = ctx.argv[0];
271
272                 if (*arg != '-' || !arg[1]) {
273                         if (ctx.flags & PARSE_OPT_STOP_AT_NON_OPTION)
274                                 break;
275                         ctx.out[ctx.cpidx++] = ctx.argv[0];
276                         continue;
277                 }
278
279                 if (arg[1] != '-') {
280                         ctx.opt = arg + 1;
281                         if (*ctx.opt == 'h')
282                                 usage_with_options(usagestr, options);
283                         if (parse_short_opt(&ctx, options) < 0)
284                                 usage_with_options(usagestr, options);
285                         if (ctx.opt)
286                                 check_typos(arg + 1, options);
287                         while (ctx.opt) {
288                                 if (*ctx.opt == 'h')
289                                         usage_with_options(usagestr, options);
290                                 if (parse_short_opt(&ctx, options) < 0)
291                                         usage_with_options(usagestr, options);
292                         }
293                         continue;
294                 }
295
296                 if (!arg[2]) { /* "--" */
297                         if (!(ctx.flags & PARSE_OPT_KEEP_DASHDASH)) {
298                                 ctx.argc--;
299                                 ctx.argv++;
300                         }
301                         break;
302                 }
303
304                 if (!strcmp(arg + 2, "help-all"))
305                         usage_with_options_internal(usagestr, options, 1, 1);
306                 if (!strcmp(arg + 2, "help"))
307                         usage_with_options(usagestr, options);
308                 if (parse_long_opt(&ctx, arg + 2, options))
309                         usage_with_options(usagestr, options);
310         }
311
312         return parse_options_end(&ctx);
313 }
314
315 #define USAGE_OPTS_WIDTH 24
316 #define USAGE_GAP         2
317
318 int usage_with_options_internal(const char * const *usagestr,
319                                 const struct option *opts, int full, int do_exit)
320 {
321         fprintf(stderr, "usage: %s\n", *usagestr++);
322         while (*usagestr && **usagestr)
323                 fprintf(stderr, "   or: %s\n", *usagestr++);
324         while (*usagestr) {
325                 fprintf(stderr, "%s%s\n",
326                                 **usagestr ? "    " : "",
327                                 *usagestr);
328                 usagestr++;
329         }
330
331         if (opts->type != OPTION_GROUP)
332                 fputc('\n', stderr);
333
334         for (; opts->type != OPTION_END; opts++) {
335                 size_t pos;
336                 int pad;
337
338                 if (opts->type == OPTION_GROUP) {
339                         fputc('\n', stderr);
340                         if (*opts->help)
341                                 fprintf(stderr, "%s\n", opts->help);
342                         continue;
343                 }
344                 if (!full && (opts->flags & PARSE_OPT_HIDDEN))
345                         continue;
346
347                 pos = fprintf(stderr, "    ");
348                 if (opts->short_name)
349                         pos += fprintf(stderr, "-%c", opts->short_name);
350                 if (opts->long_name && opts->short_name)
351                         pos += fprintf(stderr, ", ");
352                 if (opts->long_name)
353                         pos += fprintf(stderr, "--%s", opts->long_name);
354
355                 switch (opts->type) {
356                 case OPTION_ARGUMENT:
357                         break;
358                 case OPTION_INTEGER:
359                         if (opts->flags & PARSE_OPT_OPTARG)
360                                 if (opts->long_name)
361                                         pos += fprintf(stderr, "[=<n>]");
362                                 else
363                                         pos += fprintf(stderr, "[<n>]");
364                         else
365                                 pos += fprintf(stderr, " <n>");
366                         break;
367                 case OPTION_CALLBACK:
368                         if (opts->flags & PARSE_OPT_NOARG)
369                                 break;
370                         /* FALLTHROUGH */
371                 case OPTION_STRING:
372                         if (opts->argh) {
373                                 if (opts->flags & PARSE_OPT_OPTARG)
374                                         if (opts->long_name)
375                                                 pos += fprintf(stderr, "[=<%s>]", opts->argh);
376                                         else
377                                                 pos += fprintf(stderr, "[<%s>]", opts->argh);
378                                 else
379                                         pos += fprintf(stderr, " <%s>", opts->argh);
380                         } else {
381                                 if (opts->flags & PARSE_OPT_OPTARG)
382                                         if (opts->long_name)
383                                                 pos += fprintf(stderr, "[=...]");
384                                         else
385                                                 pos += fprintf(stderr, "[...]");
386                                 else
387                                         pos += fprintf(stderr, " ...");
388                         }
389                         break;
390                 default: /* OPTION_{BIT,BOOLEAN,SET_INT,SET_PTR} */
391                         break;
392                 }
393
394                 if (pos <= USAGE_OPTS_WIDTH)
395                         pad = USAGE_OPTS_WIDTH - pos;
396                 else {
397                         fputc('\n', stderr);
398                         pad = USAGE_OPTS_WIDTH;
399                 }
400                 fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
401         }
402         fputc('\n', stderr);
403
404         if (do_exit)
405                 exit(129);
406         return PARSE_OPT_HELP;
407 }
408
409 void usage_with_options(const char * const *usagestr,
410                         const struct option *opts)
411 {
412         usage_with_options_internal(usagestr, opts, 0, 1);
413         exit(129); /* make gcc happy */
414 }
415
416 int parse_options_usage(const char * const *usagestr,
417                         const struct option *opts)
418 {
419         return usage_with_options_internal(usagestr, opts, 0, 0);
420 }
421
422
423 /*----- some often used options -----*/
424 #include "cache.h"
425
426 int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
427 {
428         int v;
429
430         if (!arg) {
431                 v = unset ? 0 : DEFAULT_ABBREV;
432         } else {
433                 v = strtol(arg, (char **)&arg, 10);
434                 if (*arg)
435                         return opterror(opt, "expects a numerical value", 0);
436                 if (v && v < MINIMUM_ABBREV)
437                         v = MINIMUM_ABBREV;
438                 else if (v > 40)
439                         v = 40;
440         }
441         *(int *)(opt->value) = v;
442         return 0;
443 }
444
445 int parse_opt_approxidate_cb(const struct option *opt, const char *arg,
446                              int unset)
447 {
448         *(unsigned long *)(opt->value) = approxidate(arg);
449         return 0;
450 }