parse-options.con commit Tidy up git mergetool's backup file behaviour (44c36d1)
   1#include "git-compat-util.h"
   2#include "parse-options.h"
   3
   4#define OPT_SHORT 1
   5#define OPT_UNSET 2
   6
   7struct optparse_t {
   8        const char **argv;
   9        int argc;
  10        const char *opt;
  11};
  12
  13static 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
  24static 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
  30static 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
  39static 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 && !p->opt) {
  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 && !p->opt)
 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 && !p->opt) {
 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
 133static 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
 144static 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)) {
 165is_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
 219void check_typos(const char *arg, const struct option *options)
 220{
 221        if (strlen(arg) < 3)
 222                return;
 223
 224        if (!prefixcmp(arg, "no-")) {
 225                error ("did you mean `--%s` (with two dashes ?)", arg);
 226                exit(129);
 227        }
 228
 229        for (; options->type != OPTION_END; options++) {
 230                if (!options->long_name)
 231                        continue;
 232                if (!prefixcmp(options->long_name, arg)) {
 233                        error ("did you mean `--%s` (with two dashes ?)", arg);
 234                        exit(129);
 235                }
 236        }
 237}
 238
 239static NORETURN void usage_with_options_internal(const char * const *,
 240                                                 const struct option *, int);
 241
 242int parse_options(int argc, const char **argv, const struct option *options,
 243                  const char * const usagestr[], int flags)
 244{
 245        struct optparse_t args = { argv + 1, argc - 1, NULL };
 246        int j = 0;
 247
 248        for (; args.argc; args.argc--, args.argv++) {
 249                const char *arg = args.argv[0];
 250
 251                if (*arg != '-' || !arg[1]) {
 252                        argv[j++] = args.argv[0];
 253                        continue;
 254                }
 255
 256                if (arg[1] != '-') {
 257                        args.opt = arg + 1;
 258                        if (*args.opt == 'h')
 259                                usage_with_options(usagestr, options);
 260                        if (parse_short_opt(&args, options) < 0)
 261                                usage_with_options(usagestr, options);
 262                        if (args.opt)
 263                                check_typos(arg + 1, options);
 264                        while (args.opt) {
 265                                if (*args.opt == 'h')
 266                                        usage_with_options(usagestr, options);
 267                                if (parse_short_opt(&args, options) < 0)
 268                                        usage_with_options(usagestr, options);
 269                        }
 270                        continue;
 271                }
 272
 273                if (!arg[2]) { /* "--" */
 274                        if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
 275                                args.argc--;
 276                                args.argv++;
 277                        }
 278                        break;
 279                }
 280
 281                if (!strcmp(arg + 2, "help-all"))
 282                        usage_with_options_internal(usagestr, options, 1);
 283                if (!strcmp(arg + 2, "help"))
 284                        usage_with_options(usagestr, options);
 285                if (parse_long_opt(&args, arg + 2, options))
 286                        usage_with_options(usagestr, options);
 287        }
 288
 289        memmove(argv + j, args.argv, args.argc * sizeof(*argv));
 290        argv[j + args.argc] = NULL;
 291        return j + args.argc;
 292}
 293
 294#define USAGE_OPTS_WIDTH 24
 295#define USAGE_GAP         2
 296
 297void usage_with_options_internal(const char * const *usagestr,
 298                                 const struct option *opts, int full)
 299{
 300        fprintf(stderr, "usage: %s\n", *usagestr++);
 301        while (*usagestr && **usagestr)
 302                fprintf(stderr, "   or: %s\n", *usagestr++);
 303        while (*usagestr)
 304                fprintf(stderr, "    %s\n", *usagestr++);
 305
 306        if (opts->type != OPTION_GROUP)
 307                fputc('\n', stderr);
 308
 309        for (; opts->type != OPTION_END; opts++) {
 310                size_t pos;
 311                int pad;
 312
 313                if (opts->type == OPTION_GROUP) {
 314                        fputc('\n', stderr);
 315                        if (*opts->help)
 316                                fprintf(stderr, "%s\n", opts->help);
 317                        continue;
 318                }
 319                if (!full && (opts->flags & PARSE_OPT_HIDDEN))
 320                        continue;
 321
 322                pos = fprintf(stderr, "    ");
 323                if (opts->short_name)
 324                        pos += fprintf(stderr, "-%c", opts->short_name);
 325                if (opts->long_name && opts->short_name)
 326                        pos += fprintf(stderr, ", ");
 327                if (opts->long_name)
 328                        pos += fprintf(stderr, "--%s", opts->long_name);
 329
 330                switch (opts->type) {
 331                case OPTION_INTEGER:
 332                        if (opts->flags & PARSE_OPT_OPTARG)
 333                                pos += fprintf(stderr, " [<n>]");
 334                        else
 335                                pos += fprintf(stderr, " <n>");
 336                        break;
 337                case OPTION_CALLBACK:
 338                        if (opts->flags & PARSE_OPT_NOARG)
 339                                break;
 340                        /* FALLTHROUGH */
 341                case OPTION_STRING:
 342                        if (opts->argh) {
 343                                if (opts->flags & PARSE_OPT_OPTARG)
 344                                        pos += fprintf(stderr, " [<%s>]", opts->argh);
 345                                else
 346                                        pos += fprintf(stderr, " <%s>", opts->argh);
 347                        } else {
 348                                if (opts->flags & PARSE_OPT_OPTARG)
 349                                        pos += fprintf(stderr, " [...]");
 350                                else
 351                                        pos += fprintf(stderr, " ...");
 352                        }
 353                        break;
 354                default: /* OPTION_{BIT,BOOLEAN,SET_INT,SET_PTR} */
 355                        break;
 356                }
 357
 358                if (pos <= USAGE_OPTS_WIDTH)
 359                        pad = USAGE_OPTS_WIDTH - pos;
 360                else {
 361                        fputc('\n', stderr);
 362                        pad = USAGE_OPTS_WIDTH;
 363                }
 364                fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 365        }
 366        fputc('\n', stderr);
 367
 368        exit(129);
 369}
 370
 371void usage_with_options(const char * const *usagestr,
 372                        const struct option *opts)
 373{
 374        usage_with_options_internal(usagestr, opts, 0);
 375}
 376
 377/*----- some often used options -----*/
 378#include "cache.h"
 379
 380int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
 381{
 382        int v;
 383
 384        if (!arg) {
 385                v = unset ? 0 : DEFAULT_ABBREV;
 386        } else {
 387                v = strtol(arg, (char **)&arg, 10);
 388                if (*arg)
 389                        return opterror(opt, "expects a numerical value", 0);
 390                if (v && v < MINIMUM_ABBREV)
 391                        v = MINIMUM_ABBREV;
 392                else if (v > 40)
 393                        v = 40;
 394        }
 395        *(int *)(opt->value) = v;
 396        return 0;
 397}