dir.c

   1 /* Directory hashing for GNU Make.
   2 Copyright (C) 1988, 1989, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
   3 This file is part of GNU Make.
   4
   5 GNU Make is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 GNU Make is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with GNU Make; see the file COPYING.  If not, write to
  17 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  18
  19 #include "make.h"
  20
  21 #if     defined (POSIX) || defined (DIRENT) || defined (__GNU_LIBRARY__)
  22 #include <dirent.h>
  23 #ifndef __GNU_LIBRARY__
  24 #define D_NAMLEN(d) strlen((d)->d_name)
  25 #else   /* GNU C library.  */
  26 #define D_NAMLEN(d) ((d)->d_namlen)
  27 #endif  /* Not GNU C library.  */
  28 #else   /* Not POSIX or DIRENT.  */
  29 #define direct dirent
  30 #define D_NAMLEN(d) ((d)->d_namlen)
  31 #ifdef  SYSNDIR
  32 #include <sys/ndir.h>
  33 #endif  /* SYSNDIR */
  34 #ifdef  SYSDIR
  35 #include <sys/dir.h>
  36 #endif  /* SYSDIR */
  37 #ifdef NDIR
  38 #include <ndir.h>
  39 #endif  /* NDIR */
  40 #endif  /* POSIX or DIRENT or __GNU_LIBRARY__.  */
  41
  42 #if defined (POSIX) && !defined (__GNU_LIBRARY__)
  43 /* Posix does not require that the d_ino field be present, and some
  44    systems do not provide it. */
  45 #define REAL_DIR_ENTRY(dp) 1
  46 #else
  47 #define REAL_DIR_ENTRY(dp) (dp->d_ino != 0)
  48 #endif /* POSIX */
  49 \f
  50 #ifdef __MSDOS__
  51 #include <ctype.h>
  52
  53 static char *
  54 dosify (filename)
  55      char *filename;
  56 {
  57   static char dos_filename[14];
  58   char *df;
  59   int i;
  60
  61   if (filename == 0)
  62     return 0;
  63
  64   if (strpbrk (filename, "\"*+,;<=>?[\\]|") != 0)
  65     return filename;
  66
  67   df = dos_filename;
  68
  69   /* First, transform the name part.  */
  70   for (i = 0; *filename != '\0' && i < 8 && *filename != '.'; ++i)
  71     *df++ = tolower (*filename++);
  72
  73   /* Now skip to the next dot.  */
  74   while (*filename != '\0' && *filename != '.')
  75     ++filename;
  76   if (*filename != '\0')
  77     {
  78       *df++ = *filename++;
  79       for (i = 0; *filename != '\0' && i < 3 && *filename != '.'; ++i)
  80         *df++ = tolower (*filename++);
  81     }
  82
  83   /* Look for more dots.  */
  84   while (*filename != '\0' && *filename != '.')
  85     ++filename;
  86   if (*filename == '.')
  87     return filename;
  88   *df = 0;
  89   return dos_filename;
  90 }
  91 #endif
  92 \f
  93 /* Hash table of directories.  */
  94
  95 #ifndef DIRECTORY_BUCKETS
  96 #define DIRECTORY_BUCKETS 199
  97 #endif
  98
  99 struct directory_contents
 100   {
 101     struct directory_contents *next;
 102
 103     int dev, ino;               /* Device and inode numbers of this dir.  */
 104
 105     struct dirfile **files;     /* Files in this directory.  */
 106     DIR *dirstream;             /* Stream reading this directory.  */
 107   };
 108
 109 /* Table of directory contents hashed by device and inode number.  */
 110 static struct directory_contents *directories_contents[DIRECTORY_BUCKETS];
 111
 112 struct directory
 113   {
 114     struct directory *next;
 115
 116     char *name;                 /* Name of the directory.  */
 117
 118     /* The directory's contents.  This data may be shared by several
 119        entries in the hash table, which refer to the same directory
 120        (identified uniquely by `dev' and `ino') under different names.  */
 121     struct directory_contents *contents;
 122   };
 123
 124 /* Table of directories hashed by name.  */
 125 static struct directory *directories[DIRECTORY_BUCKETS];
 126
 127
 128 /* Never have more than this many directories open at once.  */
 129
 130 #define MAX_OPEN_DIRECTORIES 10
 131
 132 static unsigned int open_directories = 0;
 133
 134
 135 /* Hash table of files in each directory.  */
 136
 137 struct dirfile
 138   {
 139     struct dirfile *next;
 140     char *name;                 /* Name of the file.  */
 141     char impossible;            /* This file is impossible.  */
 142   };
 143
 144 #ifndef DIRFILE_BUCKETS
 145 #define DIRFILE_BUCKETS 107
 146 #endif
 147 \f
 148 static int dir_contents_file_exists_p ();
 149
 150 /* Find the directory named NAME and return its `struct directory'.  */
 151
 152 static struct directory *
 153 find_directory (name)
 154      register char *name;
 155 {
 156   register unsigned int hash = 0;
 157   register char *p;
 158   register struct directory *dir;
 159
 160   for (p = name; *p != '\0'; ++p)
 161     HASH (hash, *p);
 162   hash %= DIRECTORY_BUCKETS;
 163
 164   for (dir = directories[hash]; dir != 0; dir = dir->next)
 165     if (streq (dir->name, name))
 166       break;
 167
 168   if (dir == 0)
 169     {
 170       struct stat st;
 171
 172       /* The directory was not found.  Create a new entry for it.  */
 173
 174       dir = (struct directory *) xmalloc (sizeof (struct directory));
 175       dir->next = directories[hash];
 176       directories[hash] = dir;
 177       dir->name = savestring (name, p - name);
 178
 179       /* The directory is not in the name hash table.
 180          Find its device and inode numbers, and look it up by them.  */
 181
 182       if (safe_stat (name, &st) < 0)
 183         /* Couldn't stat the directory.  Mark this by
 184            setting the `contents' member to a nil pointer.  */
 185         dir->contents = 0;
 186       else
 187         {
 188           /* Search the contents hash table; device and inode are the key.  */
 189
 190           struct directory_contents *dc;
 191
 192           hash = ((unsigned int) st.st_dev << 16) | (unsigned int) st.st_ino;
 193           hash %= DIRECTORY_BUCKETS;
 194
 195           for (dc = directories_contents[hash]; dc != 0; dc = dc->next)
 196             if (dc->dev == st.st_dev && dc->ino == st.st_ino)
 197               break;
 198
 199           if (dc == 0)
 200             {
 201               /* Nope; this really is a directory we haven't seen before.  */
 202
 203               dc = (struct directory_contents *)
 204                 xmalloc (sizeof (struct directory_contents));
 205
 206               /* Enter it in the contents hash table.  */
 207               dc->dev = st.st_dev;
 208               dc->ino = st.st_ino;
 209               dc->next = directories_contents[hash];
 210               directories_contents[hash] = dc;
 211
 212               dc->dirstream = opendir (name);
 213               if (dc->dirstream == 0)
 214                 /* Couldn't open the directory.  Mark this by
 215                    setting the `files' member to a nil pointer.  */
 216                 dc->files = 0;
 217               else
 218                 {
 219                   /* Allocate an array of buckets for files and zero it.  */
 220                   dc->files = (struct dirfile **)
 221                     xmalloc (sizeof (struct dirfile *) * DIRFILE_BUCKETS);
 222                   bzero ((char *) dc->files,
 223                          sizeof (struct dirfile *) * DIRFILE_BUCKETS);
 224
 225                   /* Keep track of how many directories are open.  */
 226                   ++open_directories;
 227                   if (open_directories == MAX_OPEN_DIRECTORIES)
 228                     /* We have too many directories open already.
 229                        Read the entire directory and then close it.  */
 230                     (void) dir_contents_file_exists_p (dc, (char *) 0);
 231                 }
 232             }
 233
 234           /* Point the name-hashed entry for DIR at its contents data.  */
 235           dir->contents = dc;
 236         }
 237     }
 238
 239   return dir;
 240 }
 241 \f
 242 /* Return 1 if the name FILENAME is entered in DIR's hash table.
 243    FILENAME must contain no slashes.  */
 244
 245 static int
 246 dir_contents_file_exists_p (dir, filename)
 247      register struct directory_contents *dir;
 248      register char *filename;
 249 {
 250   register unsigned int hash;
 251   register char *p;
 252   register struct dirfile *df;
 253   register struct dirent *d;
 254
 255   if (dir == 0 || dir->files == 0)
 256     /* The directory could not be stat'd or opened.  */
 257     return 0;
 258
 259 #ifdef __MSDOS__
 260   filename = dosify (filename);
 261 #endif
 262
 263   hash = 0;
 264   if (filename != 0)
 265     {
 266       if (*filename == '\0')
 267         /* Checking if the directory exists.  */
 268         return 1;
 269
 270       for (p = filename; *p != '\0'; ++p)
 271         HASH (hash, *p);
 272       hash %= DIRFILE_BUCKETS;
 273
 274       /* Search the list of hashed files.  */
 275
 276       for (df = dir->files[hash]; df != 0; df = df->next)
 277         if (streq (df->name, filename))
 278           return !df->impossible;
 279     }
 280
 281   /* The file was not found in the hashed list.
 282      Try to read the directory further.  */
 283
 284   if (dir->dirstream == 0)
 285     /* The directory has been all read in.  */
 286     return 0;
 287
 288   while ((d = readdir (dir->dirstream)) != 0)
 289     {
 290       /* Enter the file in the hash table.  */
 291       register unsigned int newhash = 0;
 292       unsigned int len;
 293       register unsigned int i;
 294
 295       if (!REAL_DIR_ENTRY (d))
 296         continue;
 297
 298       len = D_NAMLEN (d);
 299       while (d->d_name[len - 1] == '\0')
 300         --len;
 301
 302       for (i = 0; i < len; ++i)
 303         HASH (newhash, d->d_name[i]);
 304       newhash %= DIRFILE_BUCKETS;
 305
 306       df = (struct dirfile *) xmalloc (sizeof (struct dirfile));
 307       df->next = dir->files[newhash];
 308       dir->files[newhash] = df;
 309       df->name = savestring (d->d_name, len);
 310       df->impossible = 0;
 311
 312       /* Check if the name matches the one we're searching for.  */
 313       if (filename != 0
 314           && newhash == hash && streq (d->d_name, filename))
 315         return 1;
 316     }
 317
 318   /* If the directory has been completely read in,
 319      close the stream and reset the pointer to nil.  */
 320   if (d == 0)
 321     {
 322       --open_directories;
 323       closedir (dir->dirstream);
 324       dir->dirstream = 0;
 325     }
 326
 327   return 0;
 328 }
 329
 330 /* Return 1 if the name FILENAME in directory DIRNAME
 331    is entered in the dir hash table.
 332    FILENAME must contain no slashes.  */
 333
 334 int
 335 dir_file_exists_p (dirname, filename)
 336      register char *dirname;
 337      register char *filename;
 338 {
 339   return dir_contents_file_exists_p (find_directory (dirname)->contents,
 340                                      filename);
 341 }
 342 \f
 343 /* Return 1 if the file named NAME exists.  */
 344
 345 int
 346 file_exists_p (name)
 347      register char *name;
 348 {
 349   char *dirend;
 350   char *dirname;
 351
 352 #ifndef NO_ARCHIVES
 353   if (ar_name (name))
 354     return ar_member_date (name) != (time_t) -1;
 355 #endif
 356
 357   dirend = rindex (name, '/');
 358   if (dirend == 0)
 359     return dir_file_exists_p (".", name);
 360
 361   dirname = (char *) alloca (dirend - name + 1);
 362   bcopy (name, dirname, dirend - name);
 363   dirname[dirend - name] = '\0';
 364   return dir_file_exists_p (dirname, dirend + 1);
 365 }
 366 \f
 367 /* Mark FILENAME as `impossible' for `file_impossible_p'.
 368    This means an attempt has been made to search for FILENAME
 369    as an intermediate file, and it has failed.  */
 370
 371 void
 372 file_impossible (filename)
 373      register char *filename;
 374 {
 375   char *dirend;
 376   register char *p = filename;
 377   register unsigned int hash;
 378   register struct directory *dir;
 379   register struct dirfile *new;
 380
 381   dirend = rindex (p, '/');
 382   if (dirend == 0)
 383     dir = find_directory (".");
 384   else
 385     {
 386       char *dirname = (char *) alloca (dirend - p + 1);
 387       bcopy (p, dirname, dirend - p);
 388       dirname[dirend - p] = '\0';
 389       dir = find_directory (dirname);
 390       filename = p = dirend + 1;
 391     }
 392
 393   for (hash = 0; *p != '\0'; ++p)
 394     HASH (hash, *p);
 395   hash %= DIRFILE_BUCKETS;
 396
 397   if (dir->contents == 0)
 398     {
 399       /* The directory could not be stat'd.  We allocate a contents
 400          structure for it, but leave it out of the contents hash table.  */
 401       dir->contents = (struct directory_contents *)
 402         xmalloc (sizeof (struct directory_contents));
 403       dir->contents->dev = dir->contents->ino = 0;
 404       dir->contents->files = 0;
 405       dir->contents->dirstream = 0;
 406     }
 407
 408   if (dir->contents->files == 0)
 409     {
 410       /* The directory was not opened; we must allocate the hash buckets.  */
 411       dir->contents->files = (struct dirfile **)
 412         xmalloc (sizeof (struct dirfile) * DIRFILE_BUCKETS);
 413       bzero ((char *) dir->contents->files,
 414              sizeof (struct dirfile) * DIRFILE_BUCKETS);
 415     }
 416
 417   /* Make a new entry and put it in the table.  */
 418
 419   new = (struct dirfile *) xmalloc (sizeof (struct dirfile));
 420   new->next = dir->contents->files[hash];
 421   dir->contents->files[hash] = new;
 422   new->name = savestring (filename, strlen (filename));
 423   new->impossible = 1;
 424 }
 425 \f
 426 /* Return nonzero if FILENAME has been marked impossible.  */
 427
 428 int
 429 file_impossible_p (filename)
 430      char *filename;
 431 {
 432   char *dirend;
 433   register char *p = filename;
 434   register unsigned int hash;
 435   register struct directory_contents *dir;
 436   register struct dirfile *next;
 437
 438   dirend = rindex (filename, '/');
 439   if (dirend == 0)
 440     dir = find_directory (".")->contents;
 441   else
 442     {
 443       char *dirname = (char *) alloca (dirend - filename + 1);
 444       bcopy (p, dirname, dirend - p);
 445       dirname[dirend - p] = '\0';
 446       dir = find_directory (dirname)->contents;
 447       p = dirend + 1;
 448     }
 449
 450   if (dir == 0 || dir->files == 0)
 451     /* There are no files entered for this directory.  */
 452     return 0;
 453
 454 #ifdef __MSDOS__
 455   p = filename = dosify (p);
 456 #endif
 457
 458   for (hash = 0; *p != '\0'; ++p)
 459     HASH (hash, *p);
 460   hash %= DIRFILE_BUCKETS;
 461
 462   for (next = dir->files[hash]; next != 0; next = next->next)
 463     if (streq (filename, next->name))
 464       return next->impossible;
 465
 466   return 0;
 467 }
 468 \f
 469 /* Return the already allocated name in the
 470    directory hash table that matches DIR.  */
 471
 472 char *
 473 dir_name (dir)
 474      char *dir;
 475 {
 476   return find_directory (dir)->name;
 477 }
 478 \f
 479 /* Print the data base of directories.  */
 480
 481 void
 482 print_dir_data_base ()
 483 {
 484   register unsigned int i, dirs, files, impossible;
 485   register struct directory *dir;
 486
 487   puts ("\n# Directories\n");
 488
 489   dirs = files = impossible = 0;
 490   for (i = 0; i < DIRECTORY_BUCKETS; ++i)
 491     for (dir = directories[i]; dir != 0; dir = dir->next)
 492       {
 493         ++dirs;
 494         if (dir->contents == 0)
 495           printf ("# %s: could not be stat'd.\n", dir->name);
 496         else if (dir->contents->files == 0)
 497           printf ("# %s (device %d, inode %d): could not be opened.\n",
 498                   dir->name, dir->contents->dev, dir->contents->ino);
 499         else
 500           {
 501             register unsigned int f = 0, im = 0;
 502             register unsigned int j;
 503             register struct dirfile *df;
 504             for (j = 0; j < DIRFILE_BUCKETS; ++j)
 505               for (df = dir->contents->files[j]; df != 0; df = df->next)
 506                 if (df->impossible)
 507                   ++im;
 508                 else
 509                   ++f;
 510             printf ("# %s (device %d, inode %d): ",
 511                     dir->name, dir->contents->dev, dir->contents->ino);
 512             if (f == 0)
 513               fputs ("No", stdout);
 514             else
 515               printf ("%u", f);
 516             fputs (" files, ", stdout);
 517             if (im == 0)
 518               fputs ("no", stdout);
 519             else
 520               printf ("%u", im);
 521             fputs (" impossibilities", stdout);
 522             if (dir->contents->dirstream == 0)
 523               puts (".");
 524             else
 525               puts (" so far.");
 526             files += f;
 527             impossible += im;
 528           }
 529       }
 530
 531   fputs ("\n# ", stdout);
 532   if (files == 0)
 533     fputs ("No", stdout);
 534   else
 535     printf ("%u", files);
 536   fputs (" files, ", stdout);
 537   if (impossible == 0)
 538     fputs ("no", stdout);
 539   else
 540     printf ("%u", impossible);
 541   printf (" impossibilities in %u directories.\n", dirs);
 542 }
 543 \f
 544 /* Hooks for globbing.  */
 545
 546 #include <glob.h>
 547
 548 /* Structure describing state of iterating through a directory hash table.  */
 549
 550 struct dirstream
 551   {
 552     struct directory_contents *contents; /* The directory being read.  */
 553
 554     unsigned int bucket;        /* Current hash bucket.  */
 555     struct dirfile *elt;        /* Current elt in bucket.  */
 556   };
 557
 558 /* Forward declarations.  */
 559 static __ptr_t open_dirstream __P ((const char *));
 560 static const char *read_dirstream __P ((__ptr_t));
 561
 562 static __ptr_t
 563 open_dirstream (directory)
 564      const char *directory;
 565 {
 566   struct dirstream *new;
 567   struct directory *dir = find_directory (directory);
 568
 569   if (dir->contents == 0 || dir->contents->files == 0)
 570     /* DIR->contents is nil if the directory could not be stat'd.
 571        DIR->contents->files is nil if it could not be opened.  */
 572     return 0;
 573
 574   /* Read all the contents of the directory now.  There is no benefit
 575      in being lazy, since glob will want to see every file anyway.  */
 576
 577   (void) dir_contents_file_exists_p (dir->contents, (char *) 0);
 578
 579   new = (struct dirstream *) xmalloc (sizeof (struct dirstream));
 580   new->contents = dir->contents;
 581   new->bucket = 0;
 582   new->elt = new->contents->files[0];
 583
 584   return (__ptr_t) new;
 585 }
 586
 587 static const char *
 588 read_dirstream (stream)
 589      __ptr_t stream;
 590 {
 591   struct dirstream *const ds = (struct dirstream *) stream;
 592   register struct dirfile *df;
 593
 594   while (ds->bucket < DIRFILE_BUCKETS)
 595     {
 596       while ((df = ds->elt) != 0)
 597         {
 598           ds->elt = df->next;
 599           if (!df->impossible)
 600             return df->name;
 601         }
 602       if (++ds->bucket == DIRFILE_BUCKETS)
 603         break;
 604       ds->elt = ds->contents->files[ds->bucket];
 605     }
 606
 607   return 0;
 608 }
 609
 610 void
 611 init_dir ()
 612 {
 613   __glob_opendir_hook = open_dirstream;
 614   __glob_readdir_hook = read_dirstream;
 615   __glob_closedir_hook = (void (*) __P ((__ptr_t stream))) free;
 616 }