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1 // Read three word input lines from stdin and produce flag #defines to stdout.
2 // The three words on each input line 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 
16 struct flag {
17   struct flag *next, *lopt;
18   char *command;
19 };
20 
chrtype(char c)21 int chrtype(char c)
22 {
23   // Does this populate a GLOBALS() variable?
24   if (strchr("^-:#|@*; %.", c)) return 1;
25 
26   // Is this followed by a numeric argument in optstr?
27   if (strchr("=<>", c)) return 2;
28 
29   if (strchr("?&0", c)) return 3;
30 
31   return 0;
32 }
33 
34 // replace chopped out USE_BLAH() sections with low-ascii characters
35 // showing how many flags got skipped so FLAG_ macros stay constant
36 
mark_gaps(char * flags,char * all)37 char *mark_gaps(char *flags, char *all)
38 {
39   char *n, *new, c;
40   int bare = 1;
41 
42   // Shell feeds in " " for blank args, leading space not meaningful.
43   while (isspace(*flags)) flags++;
44   while (isspace(*all)) all++;
45 
46   n = new = strdup(all);
47   while (*all) {
48     // --longopt parentheticals dealt with as a unit
49     if (*all == '(') {
50       int len = 0;
51 
52       while (all[len]) if (all[len++] == ')') break;
53       if (strncmp(flags, all, len)) {
54         // bare longopts need their own skip placeholders
55         if (bare) *(new++) = 1;
56       } else {
57         memcpy(new, all, len);
58         new += len;
59         flags += len;
60       }
61       all += len;
62       continue;
63     }
64     c = *(all++);
65     if (bare && !chrtype(c)) bare = 0;
66     if (*flags == c) {
67       *(new++) = c;
68       flags++;
69       continue;
70     }
71 
72     c = chrtype(c);
73     if (!c || (!bare && c==3)) *(new++) = 1;
74     else if (c==2) while (isdigit(*all)) all++;
75   }
76   *new = 0;
77 
78   return n;
79 }
80 
81 // Break down a command string into linked list of "struct flag".
82 
digest(char * string)83 struct flag *digest(char *string)
84 {
85   struct flag *list = 0;
86   char *err = string, c;
87 
88   while (*string) {
89     // Groups must be at end.
90     if (*string == '[') break;
91 
92     // Longopts
93     if (*string == '(') {
94       struct flag *new = calloc(sizeof(struct flag), 1);
95 
96       if (string[1]==')') {
97         fprintf(stderr, "empty () longopt in '%s'", err);
98         exit(1);
99       }
100       new->command = ++string;
101 
102       // Attach longopt to previous short opt, if any.
103       if (list && list->command) {
104         new->next = list->lopt;
105         list->lopt = new;
106       } else {
107         struct flag *blank = calloc(sizeof(struct flag), 1);
108 
109         blank->next = list;
110         blank->lopt = new;
111         list = blank;
112       }
113       // An empty longopt () would break this.
114       while (*++string != ')') if (*string == '-') *string = '_';
115       *(string++) = 0;
116       continue;
117     }
118 
119     c = chrtype(*string);
120     if (c == 1 || (c == 3 && !list)) string++;
121     else if (c == 2) {
122       if (string[1]=='-') string++;
123       if (!isdigit(string[1])) {
124         fprintf(stderr, "%c without number in '%s'", *string, err);
125         exit(1);
126       }
127       while (isdigit(*++string)) {
128         if (!list) {
129            string++;
130            break;
131         }
132       }
133     } else {
134       struct flag *new = calloc(sizeof(struct flag), 1);
135 
136       if (string[0]=='~' && string[1]!='(') {
137         fprintf(stderr, "~ without (longopt) in '%s'", err);
138         exit(1);
139       }
140       new->command = string++;
141       new->next = list;
142       list = new;
143     }
144   }
145 
146   return list;
147 }
148 
149 // Parse C-style octal escape
octane(char * from)150 void octane(char *from)
151 {
152   unsigned char *to = (void *)from;
153 
154   while (*from) {
155     if (*from == '\\') {
156       *to = 0;
157       while (isdigit(*++from)) *to = (8**to)+*from-'0';
158       to++;
159     } else *to++ = *from++;
160   }
161   *to = 0;
162 }
163 
main(int argc,char * argv[])164 int main(int argc, char *argv[])
165 {
166   char command[256], flags[1024], allflags[1024];
167   char *out, *outbuf = malloc(1024*1024);
168 
169   // Yes, the output buffer is 1 megabyte with no bounds checking.
170   // See "intentionally crappy", above.
171   if (!(out = outbuf)) return 1;
172 
173   printf("#undef FORCED_FLAG\n#ifdef FORCE_FLAGS\n#define FORCED_FLAG 1LL\n"
174     "#else\n#define FORCED_FLAG 0LL\n#endif\n\n");
175 
176   for (;;) {
177     struct flag *flist, *aflist, *offlist;
178     char *mgaps = 0;
179     unsigned bit;
180 
181     *command = *flags = *allflags = 0;
182     bit = fscanf(stdin, "%255s \"%1023[^\"]\" \"%1023[^\"]\"\n",
183                     command, flags, allflags);
184     octane(flags);
185     octane(allflags);
186 
187     if (getenv("DEBUG"))
188       fprintf(stderr, "command=%s, flags=%s, allflags=%s\n",
189         command, flags, allflags);
190 
191     if (!*command) break;
192     if (bit != 3) {
193       fprintf(stderr, "\nError in %s (see generated/flags.raw)\n", command);
194       exit(1);
195     }
196 
197     bit = 0;
198     printf("// %s %s %s\n", command, flags, allflags);
199     if (*flags != ' ') mgaps = mark_gaps(flags, allflags);
200     else if (*allflags != ' ') mgaps = allflags;
201     // If command disabled, use allflags for OLDTOY()
202     printf("#undef OPTSTR_%s\n#define OPTSTR_%s ", command, command);
203     if (mgaps) printf("\"%s\"\n", mgaps);
204     else printf("0\n");
205     if (mgaps != allflags) free(mgaps);
206 
207     flist = digest(flags);
208     offlist = aflist = digest(allflags);
209 
210     printf("#ifdef CLEANUP_%s\n#undef CLEANUP_%s\n#undef FOR_%s\n",
211            command, command, command);
212 
213     while (offlist) {
214       char *s = (char []){0, 0, 0, 0};
215 
216       if (!offlist->command || *offlist->command=='~')
217         s = offlist->lopt->command;
218       else {
219         *s = *offlist->command;
220         if (127 < (unsigned char)*s) sprintf(s, "X%02X", 127&*s);
221       }
222       printf("#undef FLAG_%s\n", s);
223       offlist = offlist->next;
224     }
225     printf("#endif\n\n");
226 
227     sprintf(out, "#ifdef FOR_%s\n#define CLEANUP_%s\n#ifndef TT\n#define TT this.%s\n#endif\n",
228             command, command, command);
229     out += strlen(out);
230 
231     while (aflist) {
232       char *s = (char []){0, 0, 0, 0};
233       int enabled = 0;
234 
235       // Output flag macro for bare longopts
236       if (!aflist->command || *aflist->command=='~') {
237         s = aflist->lopt->command;
238         if (flist && flist->lopt &&
239             !strcmp(flist->lopt->command, aflist->lopt->command)) enabled++;
240       // Output normal flag macro
241       } else {
242         *s = *aflist->command;
243         if (127 < (unsigned char)*s) sprintf(s, "X%02X", 127&*s);
244         if (flist && flist->command && *aflist->command == *flist->command)
245           enabled++;
246       }
247       out += sprintf(out, "#define FLAG_%s (%s<<%d)\n",
248                        s, enabled ? "1LL" : "FORCED_FLAG", bit++);
249       aflist = aflist->next;
250       if (enabled) flist = flist->next;
251     }
252     out = stpcpy(out, "#endif\n\n");
253   }
254 
255   if (fflush(0) && ferror(stdout)) return 1;
256 
257   out = outbuf;
258   while (*out) {
259     int i = write(1, outbuf, strlen(outbuf));
260 
261     if (i<0) return 1;
262     out += i;
263   }
264 
265   return 0;
266 }
267