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         const int unset = flags & OPT_UNSET;
  44
  45         if (unset && p->opt)
  46                 return opterror(opt, "takes no value", flags);
  47         if (unset && (opt->flags & PARSE_OPT_NONEG))
  48                 return opterror(opt, "isn't available", flags);
  49
  50         if (!(flags & OPT_SHORT) && p->opt) {
  51                 switch (opt->type) {
  52                 case OPTION_CALLBACK:
  53                         if (!(opt->flags & PARSE_OPT_NOARG))
  54                                 break;
  55                         /* FALLTHROUGH */
  56                 case OPTION_BOOLEAN:
  57                 case OPTION_BIT:
  58                 case OPTION_SET_INT:
  59                 case OPTION_SET_PTR:
  60                         return opterror(opt, "takes no value", flags);
  61                 default:
  62                         break;
  63                 }
  64         }
  65
  66         arg = p->opt ? p->opt : (p->argc > 1 ? p->argv[1] : NULL);
  67         switch (opt->type) {
  68         case OPTION_BIT:
  69                 if (unset)
  70                         *(int *)opt->value &= ~opt->defval;
  71                 else
  72                         *(int *)opt->value |= opt->defval;
  73                 return 0;
  74
  75         case OPTION_BOOLEAN:
  76                 *(int *)opt->value = unset ? 0 : *(int *)opt->value + 1;
  77                 return 0;
  78
  79         case OPTION_SET_INT:
  80                 *(int *)opt->value = unset ? 0 : opt->defval;
  81                 return 0;
  82
  83         case OPTION_SET_PTR:
  84                 *(void **)opt->value = unset ? NULL : (void *)opt->defval;
  85                 return 0;
  86
  87         case OPTION_STRING:
  88                 if (unset) {
  89                         *(const char **)opt->value = NULL;
  90                         return 0;
  91                 }
  92                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-')) {
  93                         *(const char **)opt->value = (const char *)opt->defval;
  94                         return 0;
  95                 }
  96                 if (!arg)
  97                         return opterror(opt, "requires a value", flags);
  98                 *(const char **)opt->value = get_arg(p);
  99                 return 0;
 100
 101         case OPTION_CALLBACK:
 102                 if (unset)
 103                         return (*opt->callback)(opt, NULL, 1);
 104                 if (opt->flags & PARSE_OPT_NOARG)
 105                         return (*opt->callback)(opt, NULL, 0);
 106                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-'))
 107                         return (*opt->callback)(opt, NULL, 0);
 108                 if (!arg)
 109                         return opterror(opt, "requires a value", flags);
 110                 return (*opt->callback)(opt, get_arg(p), 0);
 111
 112         case OPTION_INTEGER:
 113                 if (unset) {
 114                         *(int *)opt->value = 0;
 115                         return 0;
 116                 }
 117                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || !isdigit(*arg))) {
 118                         *(int *)opt->value = opt->defval;
 119                         return 0;
 120                 }
 121                 if (!arg)
 122                         return opterror(opt, "requires a value", flags);
 123                 *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
 124                 if (*s)
 125                         return opterror(opt, "expects a numerical value", flags);
 126                 return 0;
 127
 128         default:
 129                 die("should not happen, someone must be hit on the forehead");
 130         }
 131 }
 132
 133 static int parse_short_opt(struct optparse_t *p, const struct option *options)
 134 {
 135         for (; options->type != OPTION_END; options++) {
 136                 if (options->short_name == *p->opt) {
 137                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
 138                         return get_value(p, options, OPT_SHORT);
 139                 }
 140         }
 141         return error("unknown switch `%c'", *p->opt);
 142 }
 143
 144 static int parse_long_opt(struct optparse_t *p, const char *arg,
 145                           const struct option *options)
 146 {
 147         const char *arg_end = strchr(arg, '=');
 148         const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
 149         int abbrev_flags = 0, ambiguous_flags = 0;
 150
 151         if (!arg_end)
 152                 arg_end = arg + strlen(arg);
 153
 154         for (; options->type != OPTION_END; options++) {
 155                 const char *rest;
 156                 int flags = 0;
 157
 158                 if (!options->long_name)
 159                         continue;
 160
 161                 rest = skip_prefix(arg, options->long_name);
 162                 if (!rest) {
 163                         /* abbreviated? */
 164                         if (!strncmp(options->long_name, arg, arg_end - arg)) {
 165 is_abbreviated:
 166                                 if (abbrev_option) {
 167                                         /*
 168                                          * If this is abbreviated, it is
 169                                          * ambiguous. So when there is no
 170                                          * exact match later, we need to
 171                                          * error out.
 172                                          */
 173                                         ambiguous_option = abbrev_option;
 174                                         ambiguous_flags = abbrev_flags;
 175                                 }
 176                                 if (!(flags & OPT_UNSET) && *arg_end)
 177                                         p->opt = arg_end + 1;
 178                                 abbrev_option = options;
 179                                 abbrev_flags = flags;
 180                                 continue;
 181                         }
 182                         /* negated and abbreviated very much? */
 183                         if (!prefixcmp("no-", arg)) {
 184                                 flags |= OPT_UNSET;
 185                                 goto is_abbreviated;
 186                         }
 187                         /* negated? */
 188                         if (strncmp(arg, "no-", 3))
 189                                 continue;
 190                         flags |= OPT_UNSET;
 191                         rest = skip_prefix(arg + 3, options->long_name);
 192                         /* abbreviated and negated? */
 193                         if (!rest && !prefixcmp(options->long_name, arg + 3))
 194                                 goto is_abbreviated;
 195                         if (!rest)
 196                                 continue;
 197                 }
 198                 if (*rest) {
 199                         if (*rest != '=')
 200                                 continue;
 201                         p->opt = rest + 1;
 202                 }
 203                 return get_value(p, options, flags);
 204         }
 205
 206         if (ambiguous_option)
 207                 return error("Ambiguous option: %s "
 208                         "(could be --%s%s or --%s%s)",
 209                         arg,
 210                         (ambiguous_flags & OPT_UNSET) ?  "no-" : "",
 211                         ambiguous_option->long_name,
 212                         (abbrev_flags & OPT_UNSET) ?  "no-" : "",
 213                         abbrev_option->long_name);
 214         if (abbrev_option)
 215                 return get_value(p, abbrev_option, abbrev_flags);
 216         return error("unknown option `%s'", arg);
 217 }
 218
 219 int parse_options(int argc, const char **argv, const struct option *options,
 220                   const char * const usagestr[], int flags)
 221 {
 222         struct optparse_t args = { argv + 1, argc - 1, NULL };
 223         int j = 0;
 224
 225         for (; args.argc; args.argc--, args.argv++) {
 226                 const char *arg = args.argv[0];
 227
 228                 if (*arg != '-' || !arg[1]) {
 229                         argv[j++] = args.argv[0];
 230                         continue;
 231                 }
 232
 233                 if (arg[1] != '-') {
 234                         args.opt = arg + 1;
 235                         do {
 236                                 if (*args.opt == 'h')
 237                                         usage_with_options(usagestr, options);
 238                                 if (parse_short_opt(&args, options) < 0)
 239                                         usage_with_options(usagestr, options);
 240                         } while (args.opt);
 241                         continue;
 242                 }
 243
 244                 if (!arg[2]) { /* "--" */
 245                         if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
 246                                 args.argc--;
 247                                 args.argv++;
 248                         }
 249                         break;
 250                 }
 251
 252                 if (!strcmp(arg + 2, "help"))
 253                         usage_with_options(usagestr, options);
 254                 if (parse_long_opt(&args, arg + 2, options))
 255                         usage_with_options(usagestr, options);
 256         }
 257
 258         memmove(argv + j, args.argv, args.argc * sizeof(*argv));
 259         argv[j + args.argc] = NULL;
 260         return j + args.argc;
 261 }
 262
 263 #define USAGE_OPTS_WIDTH 24
 264 #define USAGE_GAP         2
 265
 266 void usage_with_options(const char * const *usagestr,
 267                         const struct option *opts)
 268 {
 269         fprintf(stderr, "usage: %s\n", *usagestr++);
 270         while (*usagestr && **usagestr)
 271                 fprintf(stderr, "   or: %s\n", *usagestr++);
 272         while (*usagestr)
 273                 fprintf(stderr, "    %s\n", *usagestr++);
 274
 275         if (opts->type != OPTION_GROUP)
 276                 fputc('\n', stderr);
 277
 278         for (; opts->type != OPTION_END; opts++) {
 279                 size_t pos;
 280                 int pad;
 281
 282                 if (opts->type == OPTION_GROUP) {
 283                         fputc('\n', stderr);
 284                         if (*opts->help)
 285                                 fprintf(stderr, "%s\n", opts->help);
 286                         continue;
 287                 }
 288
 289                 pos = fprintf(stderr, "    ");
 290                 if (opts->short_name)
 291                         pos += fprintf(stderr, "-%c", opts->short_name);
 292                 if (opts->long_name && opts->short_name)
 293                         pos += fprintf(stderr, ", ");
 294                 if (opts->long_name)
 295                         pos += fprintf(stderr, "--%s", opts->long_name);
 296
 297                 switch (opts->type) {
 298                 case OPTION_INTEGER:
 299                         if (opts->flags & PARSE_OPT_OPTARG)
 300                                 pos += fprintf(stderr, " [<n>]");
 301                         else
 302                                 pos += fprintf(stderr, " <n>");
 303                         break;
 304                 case OPTION_CALLBACK:
 305                         if (opts->flags & PARSE_OPT_NOARG)
 306                                 break;
 307                         /* FALLTHROUGH */
 308                 case OPTION_STRING:
 309                         if (opts->argh) {
 310                                 if (opts->flags & PARSE_OPT_OPTARG)
 311                                         pos += fprintf(stderr, " [<%s>]", opts->argh);
 312                                 else
 313                                         pos += fprintf(stderr, " <%s>", opts->argh);
 314                         } else {
 315                                 if (opts->flags & PARSE_OPT_OPTARG)
 316                                         pos += fprintf(stderr, " [...]");
 317                                 else
 318                                         pos += fprintf(stderr, " ...");
 319                         }
 320                         break;
 321                 default: /* OPTION_{BIT,BOOLEAN,SET_INT,SET_PTR} */
 322                         break;
 323                 }
 324
 325                 if (pos <= USAGE_OPTS_WIDTH)
 326                         pad = USAGE_OPTS_WIDTH - pos;
 327                 else {
 328                         fputc('\n', stderr);
 329                         pad = USAGE_OPTS_WIDTH;
 330                 }
 331                 fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 332         }
 333         fputc('\n', stderr);
 334
 335         exit(129);
 336 }
 337
 338 /*----- some often used options -----*/
 339 #include "cache.h"
 340
 341 int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
 342 {
 343         int v;
 344
 345         if (!arg) {
 346                 v = unset ? 0 : DEFAULT_ABBREV;
 347         } else {
 348                 v = strtol(arg, (char **)&arg, 10);
 349                 if (*arg)
 350                         return opterror(opt, "expects a numerical value", 0);
 351                 if (v && v < MINIMUM_ABBREV)
 352                         v = MINIMUM_ABBREV;
 353                 else if (v > 40)
 354                         v = 40;
 355         }
 356         *(int *)(opt->value) = v;
 357         return 0;
 358 }