xref: /third_party/toybox/scripts/mkflags.c (revision 0f66f451) 
1// Take three word input lines on stdin and produce flag #defines to stdout.
2// The three words on each input lnie are command name, option string with
3// current config, option string from allyesconfig. The three are space
4// separated and the last two are in double quotes.
5
6// This is intentionally crappy code because we control the inputs. It leaks
7// memory like a sieve and segfaults if malloc returns null, but does the job.
8
9#include <unistd.h>
10#include <stdio.h>
11#include <stdlib.h>
12#include <string.h>
13#include <errno.h>
14#include <ctype.h>
15
16struct flag {
17  struct flag *next;
18  char *command;
19  struct flag *lopt;
20};
21
22int chrtype(char c)
23{
24  // Does this populate a GLOBALS() variable?
25  if (strchr("?&^-:#|@*; %", c)) return 1;
26
27  // Is this followed by a numeric argument in optstr?
28  if (strchr("=<>", c)) return 2;
29
30  return 0;
31}
32
33// replace chopped out USE_BLAH() sections with low-ascii characters
34// showing how many flags got skipped
35
36char *mark_gaps(char *flags, char *all)
37{
38  char *n, *new, c;
39  int bare = 1;
40
41  // Shell feeds in " " for blank args, leading space not meaningful.
42  while (isspace(*flags)) flags++;
43  while (isspace(*all)) all++;
44
45  n = new = strdup(all);
46  while (*all) {
47    // --longopt parentheticals dealt with as a unit
48    if (*all == '(') {
49      int len = 0;
50
51      while (all[len++] != ')');
52      if (strncmp(flags, all, len)) {
53        // bare longopts need their own skip placeholders
54        if (bare) *(new++) = 1;
55      } else {
56        memcpy(new, all, len);
57        new += len;
58        flags += len;
59      }
60      all += len;
61      continue;
62    }
63    c = *(all++);
64    if (bare) bare = chrtype(c);
65    if (*flags == c) {
66      *(new++) = c;
67      flags++;
68      continue;
69    }
70
71    c = chrtype(c);
72    if (!c) *(new++) = 1;
73    else if (c==2) while (isdigit(*all)) all++;
74  }
75  *new = 0;
76
77  return n;
78}
79
80// Break down a command string into linked list of "struct flag".
81
82struct flag *digest(char *string)
83{
84  struct flag *list = NULL;
85  char *err = string, c;
86
87  while (*string) {
88    // Groups must be at end.
89    if (*string == '[') break;
90
91    // Longopts
92    if (*string == '(') {
93      struct flag *new = calloc(sizeof(struct flag), 1);
94
95      new->command = ++string;
96
97      // Attach longopt to previous short opt, if any.
98      if (list && list->command) {
99        new->next = list->lopt;
100        list->lopt = new;
101      } else {
102        struct flag *blank = calloc(sizeof(struct flag), 1);
103
104        blank->next = list;
105        blank->lopt = new;
106        list = blank;
107      }
108      // An empty longopt () would break this.
109      while (*++string != ')') if (*string == '-') *string = '_';
110      *(string++) = 0;
111      continue;
112    }
113
114    c = chrtype(*string);
115    if (c == 1) string++;
116    else if (c == 2) {
117      if (string[1]=='-') string++;
118      if (!isdigit(string[1])) {
119        fprintf(stderr, "%c without number in '%s'", *string, err);
120        exit(1);
121      }
122      while (isdigit(*++string)) {
123        if (!list) {
124           string++;
125           break;
126        }
127      }
128    } else {
129      struct flag *new = calloc(sizeof(struct flag), 1);
130
131      new->command = string++;
132      new->next = list;
133      list = new;
134    }
135  }
136
137  return list;
138}
139
140// Parse C-style octal escape
141void octane(char *from)
142{
143  unsigned char *to = (void *)from;
144
145  while (*from) {
146    if (*from == '\\') {
147      *to = 0;
148      while (isdigit(*++from)) *to = (8**to)+*from-'0';
149      to++;
150    } else *to++ = *from++;
151  }
152  *to = 0;
153}
154
155int main(int argc, char *argv[])
156{
157  char command[256], flags[1023], allflags[1024];
158  char *out, *outbuf = malloc(1024*1024);
159
160  // Yes, the output buffer is 1 megabyte with no bounds checking.
161  // See "intentionally crappy", above.
162  if (!(out = outbuf)) return 1;
163
164  printf("#undef FORCED_FLAG\n#undef FORCED_FLAGLL\n"
165    "#ifdef FORCE_FLAGS\n#define FORCED_FLAG 1\n#define FORCED_FLAGLL 1LL\n"
166    "#else\n#define FORCED_FLAG 0\n#define FORCED_FLAGLL 0\n#endif\n\n");
167
168  for (;;) {
169    struct flag *flist, *aflist, *offlist;
170    char *mgaps = 0;
171    unsigned bit;
172
173    *command = *flags = *allflags = 0;
174    bit = fscanf(stdin, "%255s \"%1023[^\"]\" \"%1023[^\"]\"\n",
175                    command, flags, allflags);
176    octane(flags);
177    octane(allflags);
178
179    if (getenv("DEBUG"))
180      fprintf(stderr, "command=%s, flags=%s, allflags=%s\n",
181        command, flags, allflags);
182
183    if (!*command) break;
184    if (bit != 3) {
185      fprintf(stderr, "\nError in %s (see generated/flags.raw)\n", command);
186      exit(1);
187    }
188
189    bit = 0;
190    printf("// %s %s %s\n", command, flags, allflags);
191    if (*flags != ' ') mgaps = mark_gaps(flags, allflags);
192    else if (*allflags != ' ') mgaps = allflags;
193    // If command disabled, use allflags for OLDTOY()
194    printf("#undef OPTSTR_%s\n#define OPTSTR_%s ", command, command);
195    if (mgaps) printf("\"%s\"\n", mgaps);
196    else printf("0\n");
197    if (mgaps != allflags) free(mgaps);
198
199    flist = digest(flags);
200    offlist = aflist = digest(allflags);
201
202    printf("#ifdef CLEANUP_%s\n#undef CLEANUP_%s\n#undef FOR_%s\n",
203           command, command, command);
204
205    while (offlist) {
206      char *s = (char []){0, 0, 0, 0};
207
208      if (!offlist->command) s = offlist->lopt->command;
209      else {
210        *s = *offlist->command;
211        if (127 < (unsigned char)*s) sprintf(s, "X%02X", 127&*s);
212      }
213      printf("#undef FLAG_%s\n", s);
214      offlist = offlist->next;
215    }
216    printf("#endif\n\n");
217
218    sprintf(out, "#ifdef FOR_%s\n#ifndef TT\n#define TT this.%s\n#endif\n",
219            command, command);
220    out += strlen(out);
221
222    while (aflist) {
223      char *llstr = bit>31 ? "LL" : "", *s = (char []){0, 0, 0, 0};
224      int enabled = 0;
225
226      // Output flag macro for bare longopts
227      if (!aflist->command) {
228        s = aflist->lopt->command;
229        if (flist && flist->lopt &&
230            !strcmp(flist->lopt->command, aflist->lopt->command)) enabled++;
231      // Output normal flag macro
232      } else {
233        *s = *aflist->command;
234        if (127 < (unsigned char)*s) sprintf(s, "X%02X", 127&*s);
235        if (flist && flist->command && *aflist->command == *flist->command)
236          enabled++;
237      }
238      out += sprintf(out, "#define FLAG_%s (%s%s<<%d)\n",
239                       s, enabled ? "1" : "FORCED_FLAG", llstr, bit++);
240      aflist = aflist->next;
241      if (enabled) flist = flist->next;
242    }
243    out = stpcpy(out, "#endif\n\n");
244  }
245
246  if (fflush(0) && ferror(stdout)) return 1;
247
248  out = outbuf;
249  while (*out) {
250    int i = write(1, outbuf, strlen(outbuf));
251
252    if (i<0) return 1;
253    out += i;
254  }
255
256  return 0;
257}
258