1//===-- GetOptInc.cpp -------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "lldb/Host/common/GetOptInc.h"
10
11#if defined(REPLACE_GETOPT) || defined(REPLACE_GETOPT_LONG) ||                 \
12    defined(REPLACE_GETOPT_LONG_ONLY)
13
14// getopt.cpp
15#include <errno.h>
16#include <stdlib.h>
17#include <string.h>
18
19#if defined(REPLACE_GETOPT)
20int opterr = 1;   /* if error message should be printed */
21int optind = 1;   /* index into parent argv vector */
22int optopt = '?'; /* character checked for validity */
23int optreset;     /* reset getopt */
24char *optarg;     /* argument associated with option */
25#endif
26
27#define PRINT_ERROR ((opterr) && (*options != ':'))
28
29#define FLAG_PERMUTE 0x01  /* permute non-options to the end of argv */
30#define FLAG_ALLARGS 0x02  /* treat non-options as args to option "-1" */
31#define FLAG_LONGONLY 0x04 /* operate as getopt_long_only */
32
33/* return values */
34#define BADCH (int)'?'
35#define BADARG ((*options == ':') ? (int)':' : (int)'?')
36#define INORDER (int)1
37
38#define EMSG ""
39
40static int getopt_internal(int, char *const *, const char *,
41                           const struct option *, int *, int);
42static int parse_long_options(char *const *, const char *,
43                              const struct option *, int *, int);
44static int gcd(int, int);
45static void permute_args(int, int, int, char *const *);
46
47static const char *place = EMSG; /* option letter processing */
48
49/* XXX: set optreset to 1 rather than these two */
50static int nonopt_start = -1; /* first non option argument (for permute) */
51static int nonopt_end = -1;   /* first option after non options (for permute) */
52
53/*
54* Compute the greatest common divisor of a and b.
55*/
56static int gcd(int a, int b) {
57  int c;
58
59  c = a % b;
60  while (c != 0) {
61    a = b;
62    b = c;
63    c = a % b;
64  }
65
66  return (b);
67}
68
69static void pass() {}
70#define warnx(a, ...) pass();
71
72/*
73* Exchange the block from nonopt_start to nonopt_end with the block
74* from nonopt_end to opt_end (keeping the same order of arguments
75* in each block).
76*/
77static void permute_args(int panonopt_start, int panonopt_end, int opt_end,
78                         char *const *nargv) {
79  int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
80  char *swap;
81
82  /*
83  * compute lengths of blocks and number and size of cycles
84  */
85  nnonopts = panonopt_end - panonopt_start;
86  nopts = opt_end - panonopt_end;
87  ncycle = gcd(nnonopts, nopts);
88  cyclelen = (opt_end - panonopt_start) / ncycle;
89
90  for (i = 0; i < ncycle; i++) {
91    cstart = panonopt_end + i;
92    pos = cstart;
93    for (j = 0; j < cyclelen; j++) {
94      if (pos >= panonopt_end)
95        pos -= nnonopts;
96      else
97        pos += nopts;
98      swap = nargv[pos];
99      /* LINTED const cast */
100      const_cast<char **>(nargv)[pos] = nargv[cstart];
101      /* LINTED const cast */
102      const_cast<char **>(nargv)[cstart] = swap;
103    }
104  }
105}
106
107/*
108* parse_long_options --
109*  Parse long options in argc/argv argument vector.
110* Returns -1 if short_too is set and the option does not match long_options.
111*/
112static int parse_long_options(char *const *nargv, const char *options,
113                              const struct option *long_options, int *idx,
114                              int short_too) {
115  char *current_argv, *has_equal;
116  size_t current_argv_len;
117  int i, match;
118
119  current_argv = const_cast<char *>(place);
120  match = -1;
121
122  optind++;
123
124  if ((has_equal = strchr(current_argv, '=')) != NULL) {
125    /* argument found (--option=arg) */
126    current_argv_len = has_equal - current_argv;
127    has_equal++;
128  } else
129    current_argv_len = strlen(current_argv);
130
131  for (i = 0; long_options[i].name; i++) {
132    /* find matching long option */
133    if (strncmp(current_argv, long_options[i].name, current_argv_len))
134      continue;
135
136    if (strlen(long_options[i].name) == current_argv_len) {
137      /* exact match */
138      match = i;
139      break;
140    }
141    /*
142    * If this is a known short option, don't allow
143    * a partial match of a single character.
144    */
145    if (short_too && current_argv_len == 1)
146      continue;
147
148    if (match == -1) /* partial match */
149      match = i;
150    else {
151      /* ambiguous abbreviation */
152      if (PRINT_ERROR)
153        warnx(ambig, (int)current_argv_len, current_argv);
154      optopt = 0;
155      return (BADCH);
156    }
157  }
158  if (match != -1) { /* option found */
159    if (long_options[match].has_arg == no_argument && has_equal) {
160      if (PRINT_ERROR)
161        warnx(noarg, (int)current_argv_len, current_argv);
162      /*
163      * XXX: GNU sets optopt to val regardless of flag
164      */
165      if (long_options[match].flag == NULL)
166        optopt = long_options[match].val;
167      else
168        optopt = 0;
169      return (BADARG);
170    }
171    if (long_options[match].has_arg == required_argument ||
172        long_options[match].has_arg == optional_argument) {
173      if (has_equal)
174        optarg = has_equal;
175      else if (long_options[match].has_arg == required_argument) {
176        /*
177        * optional argument doesn't use next nargv
178        */
179        optarg = nargv[optind++];
180      }
181    }
182    if ((long_options[match].has_arg == required_argument) &&
183        (optarg == NULL)) {
184      /*
185      * Missing argument; leading ':' indicates no error
186      * should be generated.
187      */
188      if (PRINT_ERROR)
189        warnx(recargstring, current_argv);
190      /*
191      * XXX: GNU sets optopt to val regardless of flag
192      */
193      if (long_options[match].flag == NULL)
194        optopt = long_options[match].val;
195      else
196        optopt = 0;
197      --optind;
198      return (BADARG);
199    }
200  } else { /* unknown option */
201    if (short_too) {
202      --optind;
203      return (-1);
204    }
205    if (PRINT_ERROR)
206      warnx(illoptstring, current_argv);
207    optopt = 0;
208    return (BADCH);
209  }
210  if (idx)
211    *idx = match;
212  if (long_options[match].flag) {
213    *long_options[match].flag = long_options[match].val;
214    return (0);
215  } else
216    return (long_options[match].val);
217}
218
219/*
220* getopt_internal --
221*  Parse argc/argv argument vector.  Called by user level routines.
222*/
223static int getopt_internal(int nargc, char *const *nargv, const char *options,
224                           const struct option *long_options, int *idx,
225                           int flags) {
226  const char *oli; /* option letter list index */
227  int optchar, short_too;
228  static int posixly_correct = -1;
229
230  if (options == NULL)
231    return (-1);
232
233  /*
234  * XXX Some GNU programs (like cvs) set optind to 0 instead of
235  * XXX using optreset.  Work around this braindamage.
236  */
237  if (optind == 0)
238    optind = optreset = 1;
239
240  /*
241  * Disable GNU extensions if POSIXLY_CORRECT is set or options
242  * string begins with a '+'.
243  */
244  if (posixly_correct == -1 || optreset)
245    posixly_correct = (getenv("POSIXLY_CORRECT") != NULL);
246  if (*options == '-')
247    flags |= FLAG_ALLARGS;
248  else if (posixly_correct || *options == '+')
249    flags &= ~FLAG_PERMUTE;
250  if (*options == '+' || *options == '-')
251    options++;
252
253  optarg = NULL;
254  if (optreset)
255    nonopt_start = nonopt_end = -1;
256start:
257  if (optreset || !*place) { /* update scanning pointer */
258    optreset = 0;
259    if (optind >= nargc) { /* end of argument vector */
260      place = EMSG;
261      if (nonopt_end != -1) {
262        /* do permutation, if we have to */
263        permute_args(nonopt_start, nonopt_end, optind, nargv);
264        optind -= nonopt_end - nonopt_start;
265      } else if (nonopt_start != -1) {
266        /*
267        * If we skipped non-options, set optind
268        * to the first of them.
269        */
270        optind = nonopt_start;
271      }
272      nonopt_start = nonopt_end = -1;
273      return (-1);
274    }
275    if (*(place = nargv[optind]) != '-' ||
276        (place[1] == '\0' && strchr(options, '-') == NULL)) {
277      place = EMSG; /* found non-option */
278      if (flags & FLAG_ALLARGS) {
279        /*
280        * GNU extension:
281        * return non-option as argument to option 1
282        */
283        optarg = nargv[optind++];
284        return (INORDER);
285      }
286      if (!(flags & FLAG_PERMUTE)) {
287        /*
288        * If no permutation wanted, stop parsing
289        * at first non-option.
290        */
291        return (-1);
292      }
293      /* do permutation */
294      if (nonopt_start == -1)
295        nonopt_start = optind;
296      else if (nonopt_end != -1) {
297        permute_args(nonopt_start, nonopt_end, optind, nargv);
298        nonopt_start = optind - (nonopt_end - nonopt_start);
299        nonopt_end = -1;
300      }
301      optind++;
302      /* process next argument */
303      goto start;
304    }
305    if (nonopt_start != -1 && nonopt_end == -1)
306      nonopt_end = optind;
307
308    /*
309    * If we have "-" do nothing, if "--" we are done.
310    */
311    if (place[1] != '\0' && *++place == '-' && place[1] == '\0') {
312      optind++;
313      place = EMSG;
314      /*
315      * We found an option (--), so if we skipped
316      * non-options, we have to permute.
317      */
318      if (nonopt_end != -1) {
319        permute_args(nonopt_start, nonopt_end, optind, nargv);
320        optind -= nonopt_end - nonopt_start;
321      }
322      nonopt_start = nonopt_end = -1;
323      return (-1);
324    }
325  }
326
327  /*
328  * Check long options if:
329  *  1) we were passed some
330  *  2) the arg is not just "-"
331  *  3) either the arg starts with -- we are getopt_long_only()
332  */
333  if (long_options != NULL && place != nargv[optind] &&
334      (*place == '-' || (flags & FLAG_LONGONLY))) {
335    short_too = 0;
336    if (*place == '-')
337      place++; /* --foo long option */
338    else if (*place != ':' && strchr(options, *place) != NULL)
339      short_too = 1; /* could be short option too */
340
341    optchar = parse_long_options(nargv, options, long_options, idx, short_too);
342    if (optchar != -1) {
343      place = EMSG;
344      return (optchar);
345    }
346  }
347
348  if ((optchar = (int)*place++) == (int)':' ||
349      (optchar == (int)'-' && *place != '\0') ||
350      (oli = strchr(options, optchar)) == NULL) {
351    /*
352    * If the user specified "-" and  '-' isn't listed in
353    * options, return -1 (non-option) as per POSIX.
354    * Otherwise, it is an unknown option character (or ':').
355    */
356    if (optchar == (int)'-' && *place == '\0')
357      return (-1);
358    if (!*place)
359      ++optind;
360    if (PRINT_ERROR)
361      warnx(illoptchar, optchar);
362    optopt = optchar;
363    return (BADCH);
364  }
365  if (long_options != NULL && optchar == 'W' && oli[1] == ';') {
366    /* -W long-option */
367    if (*place) /* no space */
368      /* NOTHING */;
369    else if (++optind >= nargc) { /* no arg */
370      place = EMSG;
371      if (PRINT_ERROR)
372        warnx(recargchar, optchar);
373      optopt = optchar;
374      return (BADARG);
375    } else /* white space */
376      place = nargv[optind];
377    optchar = parse_long_options(nargv, options, long_options, idx, 0);
378    place = EMSG;
379    return (optchar);
380  }
381  if (*++oli != ':') { /* doesn't take argument */
382    if (!*place)
383      ++optind;
384  } else { /* takes (optional) argument */
385    optarg = NULL;
386    if (*place) /* no white space */
387      optarg = const_cast<char *>(place);
388    else if (oli[1] != ':') {  /* arg not optional */
389      if (++optind >= nargc) { /* no arg */
390        place = EMSG;
391        if (PRINT_ERROR)
392          warnx(recargchar, optchar);
393        optopt = optchar;
394        return (BADARG);
395      } else
396        optarg = nargv[optind];
397    }
398    place = EMSG;
399    ++optind;
400  }
401  /* dump back option letter */
402  return (optchar);
403}
404
405/*
406* getopt --
407*  Parse argc/argv argument vector.
408*
409* [eventually this will replace the BSD getopt]
410*/
411#if defined(REPLACE_GETOPT)
412int getopt(int nargc, char *const *nargv, const char *options) {
413
414  /*
415  * We don't pass FLAG_PERMUTE to getopt_internal() since
416  * the BSD getopt(3) (unlike GNU) has never done this.
417  *
418  * Furthermore, since many privileged programs call getopt()
419  * before dropping privileges it makes sense to keep things
420  * as simple (and bug-free) as possible.
421  */
422  return (getopt_internal(nargc, nargv, options, NULL, NULL, 0));
423}
424#endif
425
426/*
427* getopt_long --
428*  Parse argc/argv argument vector.
429*/
430#if defined(REPLACE_GETOPT_LONG)
431int getopt_long(int nargc, char *const *nargv, const char *options,
432                const struct option *long_options, int *idx) {
433  return (
434      getopt_internal(nargc, nargv, options, long_options, idx, FLAG_PERMUTE));
435}
436#endif
437
438/*
439* getopt_long_only --
440*  Parse argc/argv argument vector.
441*/
442#if defined(REPLACE_GETOPT_LONG_ONLY)
443int getopt_long_only(int nargc, char *const *nargv, const char *options,
444                     const struct option *long_options, int *idx) {
445
446  return (getopt_internal(nargc, nargv, options, long_options, idx,
447                          FLAG_PERMUTE | FLAG_LONGONLY));
448}
449#endif
450
451#endif
452