scripts/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  *              !Pfilename
  34  *
  35  */
  36
  37 #define _GNU_SOURCE
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <ctype.h>
  42 #include <unistd.h>
  43 #include <limits.h>
  44 #include <errno.h>
  45 #include <sys/types.h>
  46 #include <sys/wait.h>
  47
  48 /* exitstatus is used to keep track of any failing calls to kernel-doc,
  49  * but execution continues. */
  50 int exitstatus = 0;
  51
  52 typedef void DFL(char *);
  53 DFL *defaultline;
  54
  55 typedef void FILEONLY(char * file);
  56 FILEONLY *internalfunctions;
  57 FILEONLY *externalfunctions;
  58 FILEONLY *symbolsonly;
  59 FILEONLY *findall;
  60
  61 typedef void FILELINE(char * file, char * line);
  62 FILELINE * singlefunctions;
  63 FILELINE * entity_system;
  64 FILELINE * docsection;
  65
  66 #define MAXLINESZ     2048
  67 #define MAXFILES      250
  68 #define KERNELDOCPATH "scripts/"
  69 #define KERNELDOC     "kernel-doc"
  70 #define DOCBOOK       "-docbook"
  71 #define LIST          "-list"
  72 #define FUNCTION      "-function"
  73 #define NOFUNCTION    "-nofunction"
  74 #define NODOCSECTIONS "-no-doc-sections"
  75 #define SHOWNOTFOUND  "-show-not-found"
  76
  77 static char *srctree, *kernsrctree;
  78
  79 static char **all_list = NULL;
  80 static int all_list_len = 0;
  81
  82 static void consume_symbol(const char *sym)
  83 {
  84         int i;
  85
  86         for (i = 0; i < all_list_len; i++) {
  87                 if (!all_list[i])
  88                         continue;
  89                 if (strcmp(sym, all_list[i]))
  90                         continue;
  91                 all_list[i] = NULL;
  92                 break;
  93         }
  94 }
  95
  96 static void usage (void)
  97 {
  98         fprintf(stderr, "Usage: docproc {doc|depend} file\n");
  99         fprintf(stderr, "Input is read from file.tmpl. Output is sent to stdout\n");
 100         fprintf(stderr, "doc: frontend when generating kernel documentation\n");
 101         fprintf(stderr, "depend: generate list of files referenced within file\n");
 102         fprintf(stderr, "Environment variable SRCTREE: absolute path to sources.\n");
 103         fprintf(stderr, "                     KBUILD_SRC: absolute path to kernel source tree.\n");
 104 }
 105
 106 /*
 107  * Execute kernel-doc with parameters given in svec
 108  */
 109 static void exec_kernel_doc(char **svec)
 110 {
 111         pid_t pid;
 112         int ret;
 113         char real_filename[PATH_MAX + 1];
 114         /* Make sure output generated so far are flushed */
 115         fflush(stdout);
 116         switch (pid=fork()) {
 117                 case -1:
 118                         perror("fork");
 119                         exit(1);
 120                 case  0:
 121                         memset(real_filename, 0, sizeof(real_filename));
 122                         strncat(real_filename, kernsrctree, PATH_MAX);
 123                         strncat(real_filename, "/" KERNELDOCPATH KERNELDOC,
 124                                         PATH_MAX - strlen(real_filename));
 125                         execvp(real_filename, svec);
 126                         fprintf(stderr, "exec ");
 127                         perror(real_filename);
 128                         exit(1);
 129                 default:
 130                         waitpid(pid, &ret ,0);
 131         }
 132         if (WIFEXITED(ret))
 133                 exitstatus |= WEXITSTATUS(ret);
 134         else
 135                 exitstatus = 0xff;
 136 }
 137
 138 /* Types used to create list of all exported symbols in a number of files */
 139 struct symbols
 140 {
 141         char *name;
 142 };
 143
 144 struct symfile
 145 {
 146         char *filename;
 147         struct symbols *symbollist;
 148         int symbolcnt;
 149 };
 150
 151 struct symfile symfilelist[MAXFILES];
 152 int symfilecnt = 0;
 153
 154 static void add_new_symbol(struct symfile *sym, char * symname)
 155 {
 156         sym->symbollist =
 157           realloc(sym->symbollist, (sym->symbolcnt + 1) * sizeof(char *));
 158         sym->symbollist[sym->symbolcnt++].name = strdup(symname);
 159 }
 160
 161 /* Add a filename to the list */
 162 static struct symfile * add_new_file(char * filename)
 163 {
 164         symfilelist[symfilecnt++].filename = strdup(filename);
 165         return &symfilelist[symfilecnt - 1];
 166 }
 167
 168 /* Check if file already are present in the list */
 169 static struct symfile * filename_exist(char * filename)
 170 {
 171         int i;
 172         for (i=0; i < symfilecnt; i++)
 173                 if (strcmp(symfilelist[i].filename, filename) == 0)
 174                         return &symfilelist[i];
 175         return NULL;
 176 }
 177
 178 /*
 179  * List all files referenced within the template file.
 180  * Files are separated by tabs.
 181  */
 182 static void adddep(char * file)            { printf("\t%s", file); }
 183 static void adddep2(char * file, char * line)     { line = line; adddep(file); }
 184 static void noaction(char * line)                  { line = line; }
 185 static void noaction2(char * file, char * line)   { file = file; line = line; }
 186
 187 /* Echo the line without further action */
 188 static void printline(char * line)               { printf("%s", line); }
 189
 190 /*
 191  * Find all symbols in filename that are exported with EXPORT_SYMBOL &
 192  * EXPORT_SYMBOL_GPL (& EXPORT_SYMBOL_GPL_FUTURE implicitly).
 193  * All symbols located are stored in symfilelist.
 194  */
 195 static void find_export_symbols(char * filename)
 196 {
 197         FILE * fp;
 198         struct symfile *sym;
 199         char line[MAXLINESZ];
 200         if (filename_exist(filename) == NULL) {
 201                 char real_filename[PATH_MAX + 1];
 202                 memset(real_filename, 0, sizeof(real_filename));
 203                 strncat(real_filename, srctree, PATH_MAX);
 204                 strncat(real_filename, "/", PATH_MAX - strlen(real_filename));
 205                 strncat(real_filename, filename,
 206                                 PATH_MAX - strlen(real_filename));
 207                 sym = add_new_file(filename);
 208                 fp = fopen(real_filename, "r");
 209                 if (fp == NULL) {
 210                         fprintf(stderr, "docproc: ");
 211                         perror(real_filename);
 212                         exit(1);
 213                 }
 214                 while (fgets(line, MAXLINESZ, fp)) {
 215                         char *p;
 216                         char *e;
 217                         if (((p = strstr(line, "EXPORT_SYMBOL_GPL")) != NULL) ||
 218                             ((p = strstr(line, "EXPORT_SYMBOL")) != NULL)) {
 219                                 /* Skip EXPORT_SYMBOL{_GPL} */
 220                                 while (isalnum(*p) || *p == '_')
 221                                         p++;
 222                                 /* Remove parentheses & additional whitespace */
 223                                 while (isspace(*p))
 224                                         p++;
 225                                 if (*p != '(')
 226                                         continue; /* Syntax error? */
 227                                 else
 228                                         p++;
 229                                 while (isspace(*p))
 230                                         p++;
 231                                 e = p;
 232                                 while (isalnum(*e) || *e == '_')
 233                                         e++;
 234                                 *e = '\0';
 235                                 add_new_symbol(sym, p);
 236                         }
 237                 }
 238                 fclose(fp);
 239         }
 240 }
 241
 242 /*
 243  * Document all external or internal functions in a file.
 244  * Call kernel-doc with following parameters:
 245  * kernel-doc -docbook -nofunction function_name1 filename
 246  * Function names are obtained from all the src files
 247  * by find_export_symbols.
 248  * intfunc uses -nofunction
 249  * extfunc uses -function
 250  */
 251 static void docfunctions(char * filename, char * type)
 252 {
 253         int i,j;
 254         int symcnt = 0;
 255         int idx = 0;
 256         char **vec;
 257
 258         for (i=0; i <= symfilecnt; i++)
 259                 symcnt += symfilelist[i].symbolcnt;
 260         vec = malloc((2 + 2 * symcnt + 3) * sizeof(char *));
 261         if (vec == NULL) {
 262                 perror("docproc: ");
 263                 exit(1);
 264         }
 265         vec[idx++] = KERNELDOC;
 266         vec[idx++] = DOCBOOK;
 267         vec[idx++] = NODOCSECTIONS;
 268         for (i=0; i < symfilecnt; i++) {
 269                 struct symfile * sym = &symfilelist[i];
 270                 for (j=0; j < sym->symbolcnt; j++) {
 271                         vec[idx++]     = type;
 272                         consume_symbol(sym->symbollist[j].name);
 273                         vec[idx++] = sym->symbollist[j].name;
 274                 }
 275         }
 276         vec[idx++]     = filename;
 277         vec[idx] = NULL;
 278         printf("<!-- %s -->\n", filename);
 279         exec_kernel_doc(vec);
 280         fflush(stdout);
 281         free(vec);
 282 }
 283 static void intfunc(char * filename) {  docfunctions(filename, NOFUNCTION); }
 284 static void extfunc(char * filename) { docfunctions(filename, FUNCTION);   }
 285
 286 /*
 287  * Document specific function(s) in a file.
 288  * Call kernel-doc with the following parameters:
 289  * kernel-doc -docbook -function function1 [-function function2]
 290  */
 291 static void singfunc(char * filename, char * line)
 292 {
 293         char *vec[200]; /* Enough for specific functions */
 294         int i, idx = 0;
 295         int startofsym = 1;
 296         vec[idx++] = KERNELDOC;
 297         vec[idx++] = DOCBOOK;
 298         vec[idx++] = SHOWNOTFOUND;
 299
 300         /* Split line up in individual parameters preceded by FUNCTION */
 301         for (i=0; line[i]; i++) {
 302                 if (isspace(line[i])) {
 303                         line[i] = '\0';
 304                         startofsym = 1;
 305                         continue;
 306                 }
 307                 if (startofsym) {
 308                         startofsym = 0;
 309                         vec[idx++] = FUNCTION;
 310                         vec[idx++] = &line[i];
 311                 }
 312         }
 313         for (i = 0; i < idx; i++) {
 314                 if (strcmp(vec[i], FUNCTION))
 315                         continue;
 316                 consume_symbol(vec[i + 1]);
 317         }
 318         vec[idx++] = filename;
 319         vec[idx] = NULL;
 320         exec_kernel_doc(vec);
 321 }
 322
 323 /*
 324  * Insert specific documentation section from a file.
 325  * Call kernel-doc with the following parameters:
 326  * kernel-doc -docbook -function "doc section" filename
 327  */
 328 static void docsect(char *filename, char *line)
 329 {
 330         /* kerneldoc -docbook -show-not-found -function "section" file NULL */
 331         char *vec[7];
 332         char *s;
 333
 334         for (s = line; *s; s++)
 335                 if (*s == '\n')
 336                         *s = '\0';
 337
 338         if (asprintf(&s, "DOC: %s", line) < 0) {
 339                 perror("asprintf");
 340                 exit(1);
 341         }
 342         consume_symbol(s);
 343         free(s);
 344
 345         vec[0] = KERNELDOC;
 346         vec[1] = DOCBOOK;
 347         vec[2] = SHOWNOTFOUND;
 348         vec[3] = FUNCTION;
 349         vec[4] = line;
 350         vec[5] = filename;
 351         vec[6] = NULL;
 352         exec_kernel_doc(vec);
 353 }
 354
 355 static void find_all_symbols(char *filename)
 356 {
 357         char *vec[4]; /* kerneldoc -list file NULL */
 358         pid_t pid;
 359         int ret, i, count, start;
 360         char real_filename[PATH_MAX + 1];
 361         int pipefd[2];
 362         char *data, *str;
 363         size_t data_len = 0;
 364
 365         vec[0] = KERNELDOC;
 366         vec[1] = LIST;
 367         vec[2] = filename;
 368         vec[3] = NULL;
 369
 370         if (pipe(pipefd)) {
 371                 perror("pipe");
 372                 exit(1);
 373         }
 374
 375         switch (pid=fork()) {
 376                 case -1:
 377                         perror("fork");
 378                         exit(1);
 379                 case  0:
 380                         close(pipefd[0]);
 381                         dup2(pipefd[1], 1);
 382                         memset(real_filename, 0, sizeof(real_filename));
 383                         strncat(real_filename, kernsrctree, PATH_MAX);
 384                         strncat(real_filename, "/" KERNELDOCPATH KERNELDOC,
 385                                         PATH_MAX - strlen(real_filename));
 386                         execvp(real_filename, vec);
 387                         fprintf(stderr, "exec ");
 388                         perror(real_filename);
 389                         exit(1);
 390                 default:
 391                         close(pipefd[1]);
 392                         data = malloc(4096);
 393                         do {
 394                                 while ((ret = read(pipefd[0],
 395                                                    data + data_len,
 396                                                    4096)) > 0) {
 397                                         data_len += ret;
 398                                         data = realloc(data, data_len + 4096);
 399                                 }
 400                         } while (ret == -EAGAIN);
 401                         if (ret != 0) {
 402                                 perror("read");
 403                                 exit(1);
 404                         }
 405                         waitpid(pid, &ret ,0);
 406         }
 407         if (WIFEXITED(ret))
 408                 exitstatus |= WEXITSTATUS(ret);
 409         else
 410                 exitstatus = 0xff;
 411
 412         count = 0;
 413         /* poor man's strtok, but with counting */
 414         for (i = 0; i < data_len; i++) {
 415                 if (data[i] == '\n') {
 416                         count++;
 417                         data[i] = '\0';
 418                 }
 419         }
 420         start = all_list_len;
 421         all_list_len += count;
 422         all_list = realloc(all_list, sizeof(char *) * all_list_len);
 423         str = data;
 424         for (i = 0; i < data_len && start != all_list_len; i++) {
 425                 if (data[i] == '\0') {
 426                         all_list[start] = str;
 427                         str = data + i + 1;
 428                         start++;
 429                 }
 430         }
 431 }
 432
 433 /*
 434  * Terminate s at first space, if any. If there was a space, return pointer to
 435  * the character after that. Otherwise, return pointer to the terminating NUL.
 436  */
 437 static char *chomp(char *s)
 438 {
 439         while (*s && !isspace(*s))
 440                 s++;
 441
 442         if (*s)
 443                 *s++ = '\0';
 444
 445         return s;
 446 }
 447
 448 /* Return pointer to directive content, or NULL if not a directive. */
 449 static char *is_directive(char *line)
 450 {
 451         if (line[0] == '!')
 452                 return line + 1;
 453
 454         return NULL;
 455 }
 456
 457 /*
 458  * Parse file, calling action specific functions for:
 459  * 1) Lines containing !E
 460  * 2) Lines containing !I
 461  * 3) Lines containing !D
 462  * 4) Lines containing !F
 463  * 5) Lines containing !P
 464  * 6) Lines containing !C
 465  * 7) Default lines - lines not matching the above
 466  */
 467 static void parse_file(FILE *infile)
 468 {
 469         char line[MAXLINESZ];
 470         char *p, *s;
 471         while (fgets(line, MAXLINESZ, infile)) {
 472                 p = is_directive(line);
 473                 if (!p) {
 474                         defaultline(line);
 475                         continue;
 476                 }
 477
 478                 switch (*p++) {
 479                 case 'E':
 480                         chomp(p);
 481                         externalfunctions(p);
 482                         break;
 483                 case 'I':
 484                         chomp(p);
 485                         internalfunctions(p);
 486                         break;
 487                 case 'D':
 488                         chomp(p);
 489                         symbolsonly(p);
 490                         break;
 491                 case 'F':
 492                         /* filename */
 493                         s = chomp(p);
 494                         /* function names */
 495                         while (isspace(*s))
 496                                 s++;
 497                         singlefunctions(p, s);
 498                         break;
 499                 case 'P':
 500                         /* filename */
 501                         s = chomp(p);
 502                         /* DOC: section name */
 503                         while (isspace(*s))
 504                                 s++;
 505                         docsection(p, s);
 506                         break;
 507                 case 'C':
 508                         chomp(p);
 509                         if (findall)
 510                                 findall(p);
 511                         break;
 512                 default:
 513                         defaultline(line);
 514                 }
 515         }
 516         fflush(stdout);
 517 }
 518
 519
 520 int main(int argc, char *argv[])
 521 {
 522         const char *subcommand, *filename;
 523         FILE * infile;
 524         int i;
 525
 526         srctree = getenv("SRCTREE");
 527         if (!srctree)
 528                 srctree = getcwd(NULL, 0);
 529         kernsrctree = getenv("KBUILD_SRC");
 530         if (!kernsrctree || !*kernsrctree)
 531                 kernsrctree = srctree;
 532         if (argc != 3) {
 533                 usage();
 534                 exit(1);
 535         }
 536
 537         subcommand = argv[1];
 538         filename = argv[2];
 539
 540         /* Open file, exit on error */
 541         infile = fopen(filename, "r");
 542         if (infile == NULL) {
 543                 fprintf(stderr, "docproc: ");
 544                 perror(filename);
 545                 exit(2);
 546         }
 547
 548         if (strcmp("doc", subcommand) == 0) {
 549                 /* Need to do this in two passes.
 550                  * First pass is used to collect all symbols exported
 551                  * in the various files;
 552                  * Second pass generate the documentation.
 553                  * This is required because some functions are declared
 554                  * and exported in different files :-((
 555                  */
 556                 /* Collect symbols */
 557                 defaultline       = noaction;
 558                 internalfunctions = find_export_symbols;
 559                 externalfunctions = find_export_symbols;
 560                 symbolsonly       = find_export_symbols;
 561                 singlefunctions   = noaction2;
 562                 docsection        = noaction2;
 563                 findall           = find_all_symbols;
 564                 parse_file(infile);
 565
 566                 /* Rewind to start from beginning of file again */
 567                 fseek(infile, 0, SEEK_SET);
 568                 defaultline       = printline;
 569                 internalfunctions = intfunc;
 570                 externalfunctions = extfunc;
 571                 symbolsonly       = printline;
 572                 singlefunctions   = singfunc;
 573                 docsection        = docsect;
 574                 findall           = NULL;
 575
 576                 parse_file(infile);
 577
 578                 for (i = 0; i < all_list_len; i++) {
 579                         if (!all_list[i])
 580                                 continue;
 581                         fprintf(stderr, "Warning: didn't use docs for %s\n",
 582                                 all_list[i]);
 583                 }
 584         } else if (strcmp("depend", subcommand) == 0) {
 585                 /* Create first part of dependency chain
 586                  * file.tmpl */
 587                 printf("%s\t", filename);
 588                 defaultline       = noaction;
 589                 internalfunctions = adddep;
 590                 externalfunctions = adddep;
 591                 symbolsonly       = adddep;
 592                 singlefunctions   = adddep2;
 593                 docsection        = adddep2;
 594                 findall           = adddep;
 595                 parse_file(infile);
 596                 printf("\n");
 597         } else {
 598                 fprintf(stderr, "Unknown option: %s\n", subcommand);
 599                 exit(1);
 600         }
 601         fclose(infile);
 602         fflush(stdout);
 603         return exitstatus;
 604 }