libcpp/mkdeps.c

   1 /* Dependency generator for Makefile fragments.
   2    Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
   3    Contributed by Zack Weinberg, Mar 2000
   4
   5 This program is free software; you can redistribute it and/or modify it
   6 under the terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option) any
   8 later version.
   9
  10 This program 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 this program; if not, write to the Free Software
  17 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19  In other words, you are welcome to use, share and improve this program.
  20  You are forbidden to forbid anyone else to use, share and improve
  21  what you give them.   Help stamp out software-hoarding!  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "mkdeps.h"
  26
  27 /* Keep this structure local to this file, so clients don't find it
  28    easy to start making assumptions.  */
  29 struct deps
  30 {
  31   const char **targetv;
  32   unsigned int ntargets;        /* number of slots actually occupied */
  33   unsigned int targets_size;    /* amt of allocated space - in words */
  34
  35   const char **depv;
  36   unsigned int ndeps;
  37   unsigned int deps_size;
  38
  39   const char **vpathv;
  40   size_t *vpathlv;
  41   unsigned int nvpaths;
  42   unsigned int vpaths_size;
  43 };
  44
  45 static const char *munge (const char *);
  46
  47 /* Given a filename, quote characters in that filename which are
  48    significant to Make.  Note that it's not possible to quote all such
  49    characters - e.g. \n, %, *, ?, [, \ (in some contexts), and ~ are
  50    not properly handled.  It isn't possible to get this right in any
  51    current version of Make.  (??? Still true?  Old comment referred to
  52    3.76.1.)  */
  53
  54 static const char *
  55 munge (const char *filename)
  56 {
  57   int len;
  58   const char *p, *q;
  59   char *dst, *buffer;
  60
  61   for (p = filename, len = 0; *p; p++, len++)
  62     {
  63       switch (*p)
  64         {
  65         case ' ':
  66         case '\t':
  67           /* GNU make uses a weird quoting scheme for white space.
  68              A space or tab preceded by 2N+1 backslashes represents
  69              N backslashes followed by space; a space or tab
  70              preceded by 2N backslashes represents N backslashes at
  71              the end of a file name; and backslashes in other
  72              contexts should not be doubled.  */
  73           for (q = p - 1; filename <= q && *q == '\\';  q--)
  74             len++;
  75           len++;
  76           break;
  77
  78         case '$':
  79           /* '$' is quoted by doubling it.  */
  80           len++;
  81           break;
  82         }
  83     }
  84
  85   /* Now we know how big to make the buffer.  */
  86   buffer = xmalloc (len + 1);
  87
  88   for (p = filename, dst = buffer; *p; p++, dst++)
  89     {
  90       switch (*p)
  91         {
  92         case ' ':
  93         case '\t':
  94           for (q = p - 1; filename <= q && *q == '\\';  q--)
  95             *dst++ = '\\';
  96           *dst++ = '\\';
  97           break;
  98
  99         case '$':
 100           *dst++ = '$';
 101           break;
 102
 103         default:
 104           /* nothing */;
 105         }
 106       *dst = *p;
 107     }
 108
 109   *dst = '\0';
 110   return buffer;
 111 }
 112
 113 /* If T begins with any of the partial pathnames listed in d->vpathv,
 114    then advance T to point beyond that pathname.  */
 115 static const char *
 116 apply_vpath (struct deps *d, const char *t)
 117 {
 118   if (d->vpathv)
 119     {
 120       unsigned int i;
 121       for (i = 0; i < d->nvpaths; i++)
 122         {
 123           if (!strncmp (d->vpathv[i], t, d->vpathlv[i]))
 124             {
 125               const char *p = t + d->vpathlv[i];
 126               if (!IS_DIR_SEPARATOR (*p))
 127                 goto not_this_one;
 128
 129               /* Do not simplify $(vpath)/../whatever.  ??? Might not
 130                  be necessary. */
 131               if (p[1] == '.' && p[2] == '.' && IS_DIR_SEPARATOR (p[3]))
 132                 goto not_this_one;
 133
 134               /* found a match */
 135               t = t + d->vpathlv[i] + 1;
 136               break;
 137             }
 138         not_this_one:;
 139         }
 140     }
 141
 142   /* Remove leading ./ in any case.  */
 143   while (t[0] == '.' && IS_DIR_SEPARATOR (t[1]))
 144     t += 2;
 145
 146   return t;
 147 }
 148
 149 /* Public routines.  */
 150
 151 struct deps *
 152 deps_init (void)
 153 {
 154   return xcalloc (sizeof (struct deps), 1);
 155 }
 156
 157 void
 158 deps_free (struct deps *d)
 159 {
 160   unsigned int i;
 161
 162   if (d->targetv)
 163     {
 164       for (i = 0; i < d->ntargets; i++)
 165         free ((void *) d->targetv[i]);
 166       free (d->targetv);
 167     }
 168
 169   if (d->depv)
 170     {
 171       for (i = 0; i < d->ndeps; i++)
 172         free ((void *) d->depv[i]);
 173       free (d->depv);
 174     }
 175
 176   if (d->vpathv)
 177     {
 178       for (i = 0; i < d->nvpaths; i++)
 179         free ((void *) d->vpathv[i]);
 180       free (d->vpathv);
 181       free (d->vpathlv);
 182     }
 183
 184   free (d);
 185 }
 186
 187 /* Adds a target T.  We make a copy, so it need not be a permanent
 188    string.  QUOTE is true if the string should be quoted.  */
 189 void
 190 deps_add_target (struct deps *d, const char *t, int quote)
 191 {
 192   if (d->ntargets == d->targets_size)
 193     {
 194       d->targets_size = d->targets_size * 2 + 4;
 195       d->targetv = xrealloc (d->targetv,
 196                              d->targets_size * sizeof (const char *));
 197     }
 198
 199   t = apply_vpath (d, t);
 200   if (quote)
 201     t = munge (t);  /* Also makes permanent copy.  */
 202   else
 203     t = xstrdup (t);
 204
 205   d->targetv[d->ntargets++] = t;
 206 }
 207
 208 /* Sets the default target if none has been given already.  An empty
 209    string as the default target in interpreted as stdin.  The string
 210    is quoted for MAKE.  */
 211 void
 212 deps_add_default_target (struct deps *d, const char *tgt)
 213 {
 214   /* Only if we have no targets.  */
 215   if (d->ntargets)
 216     return;
 217
 218   if (tgt[0] == '\0')
 219     deps_add_target (d, "-", 1);
 220   else
 221     {
 222 #ifndef TARGET_OBJECT_SUFFIX
 223 # define TARGET_OBJECT_SUFFIX ".o"
 224 #endif
 225       const char *start = lbasename (tgt);
 226       char *o = alloca (strlen (start) + strlen (TARGET_OBJECT_SUFFIX) + 1);
 227       char *suffix;
 228
 229       strcpy (o, start);
 230
 231       suffix = strrchr (o, '.');
 232       if (!suffix)
 233         suffix = o + strlen (o);
 234       strcpy (suffix, TARGET_OBJECT_SUFFIX);
 235
 236       deps_add_target (d, o, 1);
 237     }
 238 }
 239
 240 void
 241 deps_add_dep (struct deps *d, const char *t)
 242 {
 243   t = munge (apply_vpath (d, t));  /* Also makes permanent copy.  */
 244
 245   if (d->ndeps == d->deps_size)
 246     {
 247       d->deps_size = d->deps_size * 2 + 8;
 248       d->depv = xrealloc (d->depv, d->deps_size * sizeof (const char *));
 249     }
 250   d->depv[d->ndeps++] = t;
 251 }
 252
 253 void
 254 deps_add_vpath (struct deps *d, const char *vpath)
 255 {
 256   const char *elem, *p;
 257   char *copy;
 258   size_t len;
 259
 260   for (elem = vpath; *elem; elem = p)
 261     {
 262       for (p = elem; *p && *p != ':'; p++);
 263       len = p - elem;
 264       copy = xmalloc (len + 1);
 265       memcpy (copy, elem, len);
 266       copy[len] = '\0';
 267       if (*p == ':')
 268         p++;
 269
 270       if (d->nvpaths == d->vpaths_size)
 271         {
 272           d->vpaths_size = d->vpaths_size * 2 + 8;
 273           d->vpathv = xrealloc (d->vpathv,
 274                                 d->vpaths_size * sizeof (const char *));
 275           d->vpathlv = xrealloc (d->vpathlv, d->vpaths_size * sizeof (size_t));
 276         }
 277       d->vpathv[d->nvpaths] = copy;
 278       d->vpathlv[d->nvpaths] = len;
 279       d->nvpaths++;
 280     }
 281 }
 282
 283 void
 284 deps_write (const struct deps *d, FILE *fp, unsigned int colmax)
 285 {
 286   unsigned int size, i, column;
 287
 288   column = 0;
 289   if (colmax && colmax < 34)
 290     colmax = 34;
 291
 292   for (i = 0; i < d->ntargets; i++)
 293     {
 294       size = strlen (d->targetv[i]);
 295       column += size;
 296       if (colmax && column > colmax)
 297         {
 298           fputs (" \\\n ", fp);
 299           column = 1 + size;
 300         }
 301       if (i)
 302         {
 303           putc (' ', fp);
 304           column++;
 305         }
 306       fputs (d->targetv[i], fp);
 307     }
 308
 309   putc (':', fp);
 310   putc (' ', fp);
 311   column += 2;
 312
 313   for (i = 0; i < d->ndeps; i++)
 314     {
 315       size = strlen (d->depv[i]);
 316       column += size;
 317       if (colmax && column > colmax)
 318         {
 319           fputs (" \\\n ", fp);
 320           column = 1 + size;
 321         }
 322       if (i)
 323         {
 324           putc (' ', fp);
 325           column++;
 326         }
 327       fputs (d->depv[i], fp);
 328     }
 329   putc ('\n', fp);
 330 }
 331
 332 void
 333 deps_phony_targets (const struct deps *d, FILE *fp)
 334 {
 335   unsigned int i;
 336
 337   for (i = 1; i < d->ndeps; i++)
 338     {
 339       putc ('\n', fp);
 340       fputs (d->depv[i], fp);
 341       putc (':', fp);
 342       putc ('\n', fp);
 343     }
 344 }
 345
 346 /* Write out a deps buffer to a file, in a form that can be read back
 347    with deps_restore.  Returns nonzero on error, in which case the
 348    error number will be in errno.  */
 349
 350 int
 351 deps_save (struct deps *deps, FILE *f)
 352 {
 353   unsigned int i;
 354
 355   /* The cppreader structure contains makefile dependences.  Write out this
 356      structure.  */
 357
 358   /* The number of dependences.  */
 359   if (fwrite (&deps->ndeps, sizeof (deps->ndeps), 1, f) != 1)
 360       return -1;
 361   /* The length of each dependence followed by the string.  */
 362   for (i = 0; i < deps->ndeps; i++)
 363     {
 364       size_t num_to_write = strlen (deps->depv[i]);
 365       if (fwrite (&num_to_write, sizeof (size_t), 1, f) != 1)
 366           return -1;
 367       if (fwrite (deps->depv[i], num_to_write, 1, f) != 1)
 368           return -1;
 369     }
 370
 371   return 0;
 372 }
 373
 374 /* Read back dependency information written with deps_save into
 375    the deps buffer.  The third argument may be NULL, in which case
 376    the dependency information is just skipped, or it may be a filename,
 377    in which case that filename is skipped.  */
 378
 379 int
 380 deps_restore (struct deps *deps, FILE *fd, const char *self)
 381 {
 382   unsigned int i, count;
 383   size_t num_to_read;
 384   size_t buf_size = 512;
 385   char *buf = xmalloc (buf_size);
 386
 387   /* Number of dependences.  */
 388   if (fread (&count, 1, sizeof (count), fd) != sizeof (count))
 389     return -1;
 390
 391   /* The length of each dependence string, followed by the string.  */
 392   for (i = 0; i < count; i++)
 393     {
 394       /* Read in # bytes in string.  */
 395       if (fread (&num_to_read, 1, sizeof (size_t), fd) != sizeof (size_t))
 396         return -1;
 397       if (buf_size < num_to_read + 1)
 398         {
 399           buf_size = num_to_read + 1 + 127;
 400           buf = xrealloc (buf, buf_size);
 401         }
 402       if (fread (buf, 1, num_to_read, fd) != num_to_read)
 403         return -1;
 404       buf[num_to_read] = '\0';
 405
 406       /* Generate makefile dependencies from .pch if -nopch-deps.  */
 407       if (self != NULL && strcmp (buf, self) != 0)
 408         deps_add_dep (deps, buf);
 409     }
 410
 411   free (buf);
 412   return 0;
 413 }