libcpp/mkdeps.c

   1 /* Dependency generator for Makefile fragments.
   2    Copyright (C) 2000, 2001, 2003, 2007, 2008, 2009
   3    Free Software Foundation, Inc.
   4    Contributed by Zack Weinberg, Mar 2000
   5
   6 This program is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 3, or (at your option) any
   9 later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.
  19
  20  In other words, you are welcome to use, share and improve this program.
  21  You are forbidden to forbid anyone else to use, share and improve
  22  what you give them.   Help stamp out software-hoarding!  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "mkdeps.h"
  27
  28 /* Keep this structure local to this file, so clients don't find it
  29    easy to start making assumptions.  */
  30 struct deps
  31 {
  32   const char **targetv;
  33   unsigned int ntargets;        /* number of slots actually occupied */
  34   unsigned int targets_size;    /* amt of allocated space - in words */
  35
  36   const char **depv;
  37   unsigned int ndeps;
  38   unsigned int deps_size;
  39
  40   const char **vpathv;
  41   size_t *vpathlv;
  42   unsigned int nvpaths;
  43   unsigned int vpaths_size;
  44 };
  45
  46 static const char *munge (const char *);
  47
  48 /* Given a filename, quote characters in that filename which are
  49    significant to Make.  Note that it's not possible to quote all such
  50    characters - e.g. \n, %, *, ?, [, \ (in some contexts), and ~ are
  51    not properly handled.  It isn't possible to get this right in any
  52    current version of Make.  (??? Still true?  Old comment referred to
  53    3.76.1.)  */
  54
  55 static const char *
  56 munge (const char *filename)
  57 {
  58   int len;
  59   const char *p, *q;
  60   char *dst, *buffer;
  61
  62   for (p = filename, len = 0; *p; p++, len++)
  63     {
  64       switch (*p)
  65         {
  66         case ' ':
  67         case '\t':
  68           /* GNU make uses a weird quoting scheme for white space.
  69              A space or tab preceded by 2N+1 backslashes represents
  70              N backslashes followed by space; a space or tab
  71              preceded by 2N backslashes represents N backslashes at
  72              the end of a file name; and backslashes in other
  73              contexts should not be doubled.  */
  74           for (q = p - 1; filename <= q && *q == '\\';  q--)
  75             len++;
  76           len++;
  77           break;
  78
  79         case '$':
  80           /* '$' is quoted by doubling it.  */
  81           len++;
  82           break;
  83
  84         case '#':
  85           /* '#' is quoted with a backslash.  */
  86           len++;
  87           break;
  88         }
  89     }
  90
  91   /* Now we know how big to make the buffer.  */
  92   buffer = XNEWVEC (char, len + 1);
  93
  94   for (p = filename, dst = buffer; *p; p++, dst++)
  95     {
  96       switch (*p)
  97         {
  98         case ' ':
  99         case '\t':
 100           for (q = p - 1; filename <= q && *q == '\\';  q--)
 101             *dst++ = '\\';
 102           *dst++ = '\\';
 103           break;
 104
 105         case '$':
 106           *dst++ = '$';
 107           break;
 108
 109         case '#':
 110           *dst++ = '\\';
 111           break;
 112
 113         default:
 114           /* nothing */;
 115         }
 116       *dst = *p;
 117     }
 118
 119   *dst = '\0';
 120   return buffer;
 121 }
 122
 123 /* If T begins with any of the partial pathnames listed in d->vpathv,
 124    then advance T to point beyond that pathname.  */
 125 static const char *
 126 apply_vpath (struct deps *d, const char *t)
 127 {
 128   if (d->vpathv)
 129     {
 130       unsigned int i;
 131       for (i = 0; i < d->nvpaths; i++)
 132         {
 133           if (!strncmp (d->vpathv[i], t, d->vpathlv[i]))
 134             {
 135               const char *p = t + d->vpathlv[i];
 136               if (!IS_DIR_SEPARATOR (*p))
 137                 goto not_this_one;
 138
 139               /* Do not simplify $(vpath)/../whatever.  ??? Might not
 140                  be necessary. */
 141               if (p[1] == '.' && p[2] == '.' && IS_DIR_SEPARATOR (p[3]))
 142                 goto not_this_one;
 143
 144               /* found a match */
 145               t = t + d->vpathlv[i] + 1;
 146               break;
 147             }
 148         not_this_one:;
 149         }
 150     }
 151
 152   /* Remove leading ./ in any case.  */
 153   while (t[0] == '.' && IS_DIR_SEPARATOR (t[1]))
 154     {
 155       t += 2;
 156       /* If we removed a leading ./, then also remove any /s after the
 157          first.  */
 158       while (IS_DIR_SEPARATOR (t[0]))
 159         ++t;
 160     }
 161
 162   return t;
 163 }
 164
 165 /* Public routines.  */
 166
 167 struct deps *
 168 deps_init (void)
 169 {
 170   return XCNEW (struct deps);
 171 }
 172
 173 void
 174 deps_free (struct deps *d)
 175 {
 176   unsigned int i;
 177
 178   if (d->targetv)
 179     {
 180       for (i = 0; i < d->ntargets; i++)
 181         free ((void *) d->targetv[i]);
 182       free (d->targetv);
 183     }
 184
 185   if (d->depv)
 186     {
 187       for (i = 0; i < d->ndeps; i++)
 188         free ((void *) d->depv[i]);
 189       free (d->depv);
 190     }
 191
 192   if (d->vpathv)
 193     {
 194       for (i = 0; i < d->nvpaths; i++)
 195         free ((void *) d->vpathv[i]);
 196       free (d->vpathv);
 197       free (d->vpathlv);
 198     }
 199
 200   free (d);
 201 }
 202
 203 /* Adds a target T.  We make a copy, so it need not be a permanent
 204    string.  QUOTE is true if the string should be quoted.  */
 205 void
 206 deps_add_target (struct deps *d, const char *t, int quote)
 207 {
 208   if (d->ntargets == d->targets_size)
 209     {
 210       d->targets_size = d->targets_size * 2 + 4;
 211       d->targetv = XRESIZEVEC (const char *, d->targetv, d->targets_size);
 212     }
 213
 214   t = apply_vpath (d, t);
 215   if (quote)
 216     t = munge (t);  /* Also makes permanent copy.  */
 217   else
 218     t = xstrdup (t);
 219
 220   d->targetv[d->ntargets++] = t;
 221 }
 222
 223 /* Sets the default target if none has been given already.  An empty
 224    string as the default target in interpreted as stdin.  The string
 225    is quoted for MAKE.  */
 226 void
 227 deps_add_default_target (struct deps *d, const char *tgt)
 228 {
 229   /* Only if we have no targets.  */
 230   if (d->ntargets)
 231     return;
 232
 233   if (tgt[0] == '\0')
 234     deps_add_target (d, "-", 1);
 235   else
 236     {
 237 #ifndef TARGET_OBJECT_SUFFIX
 238 # define TARGET_OBJECT_SUFFIX ".o"
 239 #endif
 240       const char *start = lbasename (tgt);
 241       char *o = (char *) alloca (strlen (start)
 242                                  + strlen (TARGET_OBJECT_SUFFIX) + 1);
 243       char *suffix;
 244
 245       strcpy (o, start);
 246
 247       suffix = strrchr (o, '.');
 248       if (!suffix)
 249         suffix = o + strlen (o);
 250       strcpy (suffix, TARGET_OBJECT_SUFFIX);
 251
 252       deps_add_target (d, o, 1);
 253     }
 254 }
 255
 256 void
 257 deps_add_dep (struct deps *d, const char *t)
 258 {
 259   t = munge (apply_vpath (d, t));  /* Also makes permanent copy.  */
 260
 261   if (d->ndeps == d->deps_size)
 262     {
 263       d->deps_size = d->deps_size * 2 + 8;
 264       d->depv = XRESIZEVEC (const char *, d->depv, d->deps_size);
 265     }
 266   d->depv[d->ndeps++] = t;
 267 }
 268
 269 void
 270 deps_add_vpath (struct deps *d, const char *vpath)
 271 {
 272   const char *elem, *p;
 273   char *copy;
 274   size_t len;
 275
 276   for (elem = vpath; *elem; elem = p)
 277     {
 278       for (p = elem; *p && *p != ':'; p++);
 279       len = p - elem;
 280       copy = XNEWVEC (char, len + 1);
 281       memcpy (copy, elem, len);
 282       copy[len] = '\0';
 283       if (*p == ':')
 284         p++;
 285
 286       if (d->nvpaths == d->vpaths_size)
 287         {
 288           d->vpaths_size = d->vpaths_size * 2 + 8;
 289           d->vpathv = XRESIZEVEC (const char *, d->vpathv, d->vpaths_size);
 290           d->vpathlv = XRESIZEVEC (size_t, d->vpathlv, d->vpaths_size);
 291         }
 292       d->vpathv[d->nvpaths] = copy;
 293       d->vpathlv[d->nvpaths] = len;
 294       d->nvpaths++;
 295     }
 296 }
 297
 298 void
 299 deps_write (const struct deps *d, FILE *fp, unsigned int colmax)
 300 {
 301   unsigned int size, i, column;
 302
 303   column = 0;
 304   if (colmax && colmax < 34)
 305     colmax = 34;
 306
 307   for (i = 0; i < d->ntargets; i++)
 308     {
 309       size = strlen (d->targetv[i]);
 310       column += size;
 311       if (i)
 312         {
 313           if (colmax && column > colmax)
 314             {
 315               fputs (" \\\n ", fp);
 316               column = 1 + size;
 317             }
 318           else
 319             {
 320               putc (' ', fp);
 321               column++;
 322             }
 323         }
 324       fputs (d->targetv[i], fp);
 325     }
 326
 327   putc (':', fp);
 328   column++;
 329
 330   for (i = 0; i < d->ndeps; i++)
 331     {
 332       size = strlen (d->depv[i]);
 333       column += size;
 334       if (colmax && column > colmax)
 335         {
 336           fputs (" \\\n ", fp);
 337           column = 1 + size;
 338         }
 339       else
 340         {
 341           putc (' ', fp);
 342           column++;
 343         }
 344       fputs (d->depv[i], fp);
 345     }
 346   putc ('\n', fp);
 347 }
 348
 349 void
 350 deps_phony_targets (const struct deps *d, FILE *fp)
 351 {
 352   unsigned int i;
 353
 354   for (i = 1; i < d->ndeps; i++)
 355     {
 356       putc ('\n', fp);
 357       fputs (d->depv[i], fp);
 358       putc (':', fp);
 359       putc ('\n', fp);
 360     }
 361 }
 362
 363 /* Write out a deps buffer to a file, in a form that can be read back
 364    with deps_restore.  Returns nonzero on error, in which case the
 365    error number will be in errno.  */
 366
 367 int
 368 deps_save (struct deps *deps, FILE *f)
 369 {
 370   unsigned int i;
 371
 372   /* The cppreader structure contains makefile dependences.  Write out this
 373      structure.  */
 374
 375   /* The number of dependences.  */
 376   if (fwrite (&deps->ndeps, sizeof (deps->ndeps), 1, f) != 1)
 377       return -1;
 378   /* The length of each dependence followed by the string.  */
 379   for (i = 0; i < deps->ndeps; i++)
 380     {
 381       size_t num_to_write = strlen (deps->depv[i]);
 382       if (fwrite (&num_to_write, sizeof (size_t), 1, f) != 1)
 383           return -1;
 384       if (fwrite (deps->depv[i], num_to_write, 1, f) != 1)
 385           return -1;
 386     }
 387
 388   return 0;
 389 }
 390
 391 /* Read back dependency information written with deps_save into
 392    the deps buffer.  The third argument may be NULL, in which case
 393    the dependency information is just skipped, or it may be a filename,
 394    in which case that filename is skipped.  */
 395
 396 int
 397 deps_restore (struct deps *deps, FILE *fd, const char *self)
 398 {
 399   unsigned int i, count;
 400   size_t num_to_read;
 401   size_t buf_size = 512;
 402   char *buf = XNEWVEC (char, buf_size);
 403
 404   /* Number of dependences.  */
 405   if (fread (&count, 1, sizeof (count), fd) != sizeof (count))
 406     return -1;
 407
 408   /* The length of each dependence string, followed by the string.  */
 409   for (i = 0; i < count; i++)
 410     {
 411       /* Read in # bytes in string.  */
 412       if (fread (&num_to_read, 1, sizeof (size_t), fd) != sizeof (size_t))
 413         return -1;
 414       if (buf_size < num_to_read + 1)
 415         {
 416           buf_size = num_to_read + 1 + 127;
 417           buf = XRESIZEVEC (char, buf, buf_size);
 418         }
 419       if (fread (buf, 1, num_to_read, fd) != num_to_read)
 420         return -1;
 421       buf[num_to_read] = '\0';
 422
 423       /* Generate makefile dependencies from .pch if -nopch-deps.  */
 424       if (self != NULL && strcmp (buf, self) != 0)
 425         deps_add_dep (deps, buf);
 426     }
 427
 428   free (buf);
 429   return 0;
 430 }