kbuild: stop docproc segfaulting when SRCTREE isn't set.
[linux-2.6] / scripts / basic / docproc.c
1 /*
2  *      docproc is a simple preprocessor for the template files
3  *      used as placeholders for the kernel internal documentation.
4  *      docproc is used for documentation-frontend and
5  *      dependency-generator.
6  *      The two usages have in common that they require
7  *      some knowledge of the .tmpl syntax, therefore they
8  *      are kept together.
9  *
10  *      documentation-frontend
11  *              Scans the template file and call kernel-doc for
12  *              all occurrences of ![EIF]file
13  *              Beforehand each referenced file is scanned for
14  *              any symbols that are exported via these macros:
15  *                      EXPORT_SYMBOL(), EXPORT_SYMBOL_GPL(), &
16  *                      EXPORT_SYMBOL_GPL_FUTURE()
17  *              This is used to create proper -function and
18  *              -nofunction arguments in calls to kernel-doc.
19  *              Usage: docproc doc file.tmpl
20  *
21  *      dependency-generator:
22  *              Scans the template file and list all files
23  *              referenced in a format recognized by make.
24  *              Usage:  docproc depend file.tmpl
25  *              Writes dependency information to stdout
26  *              in the following format:
27  *              file.tmpl src.c src2.c
28  *              The filenames are obtained from the following constructs:
29  *              !Efilename
30  *              !Ifilename
31  *              !Dfilename
32  *              !Ffilename
33  *
34  */
35
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <ctype.h>
40 #include <unistd.h>
41 #include <limits.h>
42 #include <sys/types.h>
43 #include <sys/wait.h>
44
45 /* exitstatus is used to keep track of any failing calls to kernel-doc,
46  * but execution continues. */
47 int exitstatus = 0;
48
49 typedef void DFL(char *);
50 DFL *defaultline;
51
52 typedef void FILEONLY(char * file);
53 FILEONLY *internalfunctions;
54 FILEONLY *externalfunctions;
55 FILEONLY *symbolsonly;
56
57 typedef void FILELINE(char * file, char * line);
58 FILELINE * singlefunctions;
59 FILELINE * entity_system;
60
61 #define MAXLINESZ     2048
62 #define MAXFILES      250
63 #define KERNELDOCPATH "scripts/"
64 #define KERNELDOC     "kernel-doc"
65 #define DOCBOOK       "-docbook"
66 #define FUNCTION      "-function"
67 #define NOFUNCTION    "-nofunction"
68
69 char *srctree;
70
71 void usage (void)
72 {
73         fprintf(stderr, "Usage: docproc {doc|depend} file\n");
74         fprintf(stderr, "Input is read from file.tmpl. Output is sent to stdout\n");
75         fprintf(stderr, "doc: frontend when generating kernel documentation\n");
76         fprintf(stderr, "depend: generate list of files referenced within file\n");
77         fprintf(stderr, "Environment variable SRCTREE: absolute path to kernel source tree.\n");
78 }
79
80 /*
81  * Execute kernel-doc with parameters given in svec
82  */
83 void exec_kernel_doc(char **svec)
84 {
85         pid_t pid;
86         int ret;
87         char real_filename[PATH_MAX + 1];
88         /* Make sure output generated so far are flushed */
89         fflush(stdout);
90         switch (pid=fork()) {
91                 case -1:
92                         perror("fork");
93                         exit(1);
94                 case  0:
95                         memset(real_filename, 0, sizeof(real_filename));
96                         strncat(real_filename, srctree, PATH_MAX);
97                         strncat(real_filename, KERNELDOCPATH KERNELDOC,
98                                         PATH_MAX - strlen(real_filename));
99                         execvp(real_filename, svec);
100                         fprintf(stderr, "exec ");
101                         perror(real_filename);
102                         exit(1);
103                 default:
104                         waitpid(pid, &ret ,0);
105         }
106         if (WIFEXITED(ret))
107                 exitstatus |= WEXITSTATUS(ret);
108         else
109                 exitstatus = 0xff;
110 }
111
112 /* Types used to create list of all exported symbols in a number of files */
113 struct symbols
114 {
115         char *name;
116 };
117
118 struct symfile
119 {
120         char *filename;
121         struct symbols *symbollist;
122         int symbolcnt;
123 };
124
125 struct symfile symfilelist[MAXFILES];
126 int symfilecnt = 0;
127
128 void add_new_symbol(struct symfile *sym, char * symname)
129 {
130         sym->symbollist =
131           realloc(sym->symbollist, (sym->symbolcnt + 1) * sizeof(char *));
132         sym->symbollist[sym->symbolcnt++].name = strdup(symname);
133 }
134
135 /* Add a filename to the list */
136 struct symfile * add_new_file(char * filename)
137 {
138         symfilelist[symfilecnt++].filename = strdup(filename);
139         return &symfilelist[symfilecnt - 1];
140 }
141
142 /* Check if file already are present in the list */
143 struct symfile * filename_exist(char * filename)
144 {
145         int i;
146         for (i=0; i < symfilecnt; i++)
147                 if (strcmp(symfilelist[i].filename, filename) == 0)
148                         return &symfilelist[i];
149         return NULL;
150 }
151
152 /*
153  * List all files referenced within the template file.
154  * Files are separated by tabs.
155  */
156 void adddep(char * file)                   { printf("\t%s", file); }
157 void adddep2(char * file, char * line)     { line = line; adddep(file); }
158 void noaction(char * line)                 { line = line; }
159 void noaction2(char * file, char * line)   { file = file; line = line; }
160
161 /* Echo the line without further action */
162 void printline(char * line)               { printf("%s", line); }
163
164 /*
165  * Find all symbols in filename that are exported with EXPORT_SYMBOL &
166  * EXPORT_SYMBOL_GPL (& EXPORT_SYMBOL_GPL_FUTURE implicitly).
167  * All symbols located are stored in symfilelist.
168  */
169 void find_export_symbols(char * filename)
170 {
171         FILE * fp;
172         struct symfile *sym;
173         char line[MAXLINESZ];
174         if (filename_exist(filename) == NULL) {
175                 char real_filename[PATH_MAX + 1];
176                 memset(real_filename, 0, sizeof(real_filename));
177                 strncat(real_filename, srctree, PATH_MAX);
178                 strncat(real_filename, filename,
179                                 PATH_MAX - strlen(real_filename));
180                 sym = add_new_file(filename);
181                 fp = fopen(real_filename, "r");
182                 if (fp == NULL)
183                 {
184                         fprintf(stderr, "docproc: ");
185                         perror(real_filename);
186                         exit(1);
187                 }
188                 while (fgets(line, MAXLINESZ, fp)) {
189                         char *p;
190                         char *e;
191                         if (((p = strstr(line, "EXPORT_SYMBOL_GPL")) != NULL) ||
192                             ((p = strstr(line, "EXPORT_SYMBOL")) != NULL)) {
193                                 /* Skip EXPORT_SYMBOL{_GPL} */
194                                 while (isalnum(*p) || *p == '_')
195                                         p++;
196                                 /* Remove parentheses & additional whitespace */
197                                 while (isspace(*p))
198                                         p++;
199                                 if (*p != '(')
200                                         continue; /* Syntax error? */
201                                 else
202                                         p++;
203                                 while (isspace(*p))
204                                         p++;
205                                 e = p;
206                                 while (isalnum(*e) || *e == '_')
207                                         e++;
208                                 *e = '\0';
209                                 add_new_symbol(sym, p);
210                         }
211                 }
212                 fclose(fp);
213         }
214 }
215
216 /*
217  * Document all external or internal functions in a file.
218  * Call kernel-doc with following parameters:
219  * kernel-doc -docbook -nofunction function_name1 filename
220  * Function names are obtained from all the src files
221  * by find_export_symbols.
222  * intfunc uses -nofunction
223  * extfunc uses -function
224  */
225 void docfunctions(char * filename, char * type)
226 {
227         int i,j;
228         int symcnt = 0;
229         int idx = 0;
230         char **vec;
231
232         for (i=0; i <= symfilecnt; i++)
233                 symcnt += symfilelist[i].symbolcnt;
234         vec = malloc((2 + 2 * symcnt + 2) * sizeof(char*));
235         if (vec == NULL) {
236                 perror("docproc: ");
237                 exit(1);
238         }
239         vec[idx++] = KERNELDOC;
240         vec[idx++] = DOCBOOK;
241         for (i=0; i < symfilecnt; i++) {
242                 struct symfile * sym = &symfilelist[i];
243                 for (j=0; j < sym->symbolcnt; j++) {
244                         vec[idx++]     = type;
245                         vec[idx++] = sym->symbollist[j].name;
246                 }
247         }
248         vec[idx++]     = filename;
249         vec[idx] = NULL;
250         printf("<!-- %s -->\n", filename);
251         exec_kernel_doc(vec);
252         fflush(stdout);
253         free(vec);
254 }
255 void intfunc(char * filename) { docfunctions(filename, NOFUNCTION); }
256 void extfunc(char * filename) { docfunctions(filename, FUNCTION);   }
257
258 /*
259  * Document specific function(s) in a file.
260  * Call kernel-doc with the following parameters:
261  * kernel-doc -docbook -function function1 [-function function2]
262  */
263 void singfunc(char * filename, char * line)
264 {
265         char *vec[200]; /* Enough for specific functions */
266         int i, idx = 0;
267         int startofsym = 1;
268         vec[idx++] = KERNELDOC;
269         vec[idx++] = DOCBOOK;
270
271         /* Split line up in individual parameters preceded by FUNCTION */
272         for (i=0; line[i]; i++) {
273                 if (isspace(line[i])) {
274                         line[i] = '\0';
275                         startofsym = 1;
276                         continue;
277                 }
278                 if (startofsym) {
279                         startofsym = 0;
280                         vec[idx++] = FUNCTION;
281                         vec[idx++] = &line[i];
282                 }
283         }
284         vec[idx++] = filename;
285         vec[idx] = NULL;
286         exec_kernel_doc(vec);
287 }
288
289 /*
290  * Parse file, calling action specific functions for:
291  * 1) Lines containing !E
292  * 2) Lines containing !I
293  * 3) Lines containing !D
294  * 4) Lines containing !F
295  * 5) Default lines - lines not matching the above
296  */
297 void parse_file(FILE *infile)
298 {
299         char line[MAXLINESZ];
300         char * s;
301         while (fgets(line, MAXLINESZ, infile)) {
302                 if (line[0] == '!') {
303                         s = line + 2;
304                         switch (line[1]) {
305                                 case 'E':
306                                         while (*s && !isspace(*s)) s++;
307                                         *s = '\0';
308                                         externalfunctions(line+2);
309                                         break;
310                                 case 'I':
311                                         while (*s && !isspace(*s)) s++;
312                                         *s = '\0';
313                                         internalfunctions(line+2);
314                                         break;
315                                 case 'D':
316                                         while (*s && !isspace(*s)) s++;
317                                         *s = '\0';
318                                         symbolsonly(line+2);
319                                         break;
320                                 case 'F':
321                                         /* filename */
322                                         while (*s && !isspace(*s)) s++;
323                                         *s++ = '\0';
324                                         /* function names */
325                                         while (isspace(*s))
326                                                 s++;
327                                         singlefunctions(line +2, s);
328                                         break;
329                                 default:
330                                         defaultline(line);
331                         }
332                 }
333                 else {
334                         defaultline(line);
335                 }
336         }
337         fflush(stdout);
338 }
339
340
341 int main(int argc, char *argv[])
342 {
343         FILE * infile;
344
345         srctree = getenv("SRCTREE");
346         if (!srctree)
347                 srctree = getcwd(NULL, 0);
348         if (argc != 3) {
349                 usage();
350                 exit(1);
351         }
352         /* Open file, exit on error */
353         infile = fopen(argv[2], "r");
354         if (infile == NULL) {
355                 fprintf(stderr, "docproc: ");
356                 perror(argv[2]);
357                 exit(2);
358         }
359
360         if (strcmp("doc", argv[1]) == 0)
361         {
362                 /* Need to do this in two passes.
363                  * First pass is used to collect all symbols exported
364                  * in the various files;
365                  * Second pass generate the documentation.
366                  * This is required because some functions are declared
367                  * and exported in different files :-((
368                  */
369                 /* Collect symbols */
370                 defaultline       = noaction;
371                 internalfunctions = find_export_symbols;
372                 externalfunctions = find_export_symbols;
373                 symbolsonly       = find_export_symbols;
374                 singlefunctions   = noaction2;
375                 parse_file(infile);
376
377                 /* Rewind to start from beginning of file again */
378                 fseek(infile, 0, SEEK_SET);
379                 defaultline       = printline;
380                 internalfunctions = intfunc;
381                 externalfunctions = extfunc;
382                 symbolsonly       = printline;
383                 singlefunctions   = singfunc;
384
385                 parse_file(infile);
386         }
387         else if (strcmp("depend", argv[1]) == 0)
388         {
389                 /* Create first part of dependency chain
390                  * file.tmpl */
391                 printf("%s\t", argv[2]);
392                 defaultline       = noaction;
393                 internalfunctions = adddep;
394                 externalfunctions = adddep;
395                 symbolsonly       = adddep;
396                 singlefunctions   = adddep2;
397                 parse_file(infile);
398                 printf("\n");
399         }
400         else
401         {
402                 fprintf(stderr, "Unknown option: %s\n", argv[1]);
403                 exit(1);
404         }
405         fclose(infile);
406         fflush(stdout);
407         return exitstatus;
408 }