gcc/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
  40 static const char *munge (const char *);
  41
  42 /* Given a filename, quote characters in that filename which are
  43    significant to Make.  Note that it's not possible to quote all such
  44    characters - e.g. \n, %, *, ?, [, \ (in some contexts), and ~ are
  45    not properly handled.  It isn't possible to get this right in any
  46    current version of Make.  (??? Still true?  Old comment referred to
  47    3.76.1.)  */
  48
  49 static const char *
  50 munge (const char *filename)
  51 {
  52   int len;
  53   const char *p, *q;
  54   char *dst, *buffer;
  55
  56   for (p = filename, len = 0; *p; p++, len++)
  57     {
  58       switch (*p)
  59         {
  60         case ' ':
  61         case '\t':
  62           /* GNU make uses a weird quoting scheme for white space.
  63              A space or tab preceded by 2N+1 backslashes represents
  64              N backslashes followed by space; a space or tab
  65              preceded by 2N backslashes represents N backslashes at
  66              the end of a file name; and backslashes in other
  67              contexts should not be doubled.  */
  68           for (q = p - 1; filename <= q && *q == '\\';  q--)
  69             len++;
  70           len++;
  71           break;
  72
  73         case '$':
  74           /* '$' is quoted by doubling it.  */
  75           len++;
  76           break;
  77         }
  78     }
  79
  80   /* Now we know how big to make the buffer.  */
  81   buffer = xmalloc (len + 1);
  82
  83   for (p = filename, dst = buffer; *p; p++, dst++)
  84     {
  85       switch (*p)
  86         {
  87         case ' ':
  88         case '\t':
  89           for (q = p - 1; filename <= q && *q == '\\';  q--)
  90             *dst++ = '\\';
  91           *dst++ = '\\';
  92           break;
  93
  94         case '$':
  95           *dst++ = '$';
  96           break;
  97
  98         default:
  99           /* nothing */;
 100         }
 101       *dst = *p;
 102     }
 103
 104   *dst = '\0';
 105   return buffer;
 106 }
 107
 108 /* Public routines.  */
 109
 110 struct deps *
 111 deps_init (void)
 112 {
 113   struct deps *d = xmalloc (sizeof (struct deps));
 114
 115   /* Allocate space for the vectors only if we need it.  */
 116
 117   d->targetv = 0;
 118   d->depv = 0;
 119
 120   d->ntargets = 0;
 121   d->targets_size = 0;
 122   d->ndeps = 0;
 123   d->deps_size = 0;
 124
 125   return d;
 126 }
 127
 128 void
 129 deps_free (struct deps *d)
 130 {
 131   unsigned int i;
 132
 133   if (d->targetv)
 134     {
 135       for (i = 0; i < d->ntargets; i++)
 136         free ((void *) d->targetv[i]);
 137       free (d->targetv);
 138     }
 139
 140   if (d->depv)
 141     {
 142       for (i = 0; i < d->ndeps; i++)
 143         free ((void *) d->depv[i]);
 144       free (d->depv);
 145     }
 146
 147   free (d);
 148 }
 149
 150 /* Adds a target T.  We make a copy, so it need not be a permanent
 151    string.  QUOTE is true if the string should be quoted.  */
 152 void
 153 deps_add_target (struct deps *d, const char *t, int quote)
 154 {
 155   if (d->ntargets == d->targets_size)
 156     {
 157       d->targets_size = d->targets_size * 2 + 4;
 158       d->targetv = xrealloc (d->targetv,
 159                              d->targets_size * sizeof (const char *));
 160     }
 161
 162   if (quote)
 163     t = munge (t);  /* Also makes permanent copy.  */
 164   else
 165     t = xstrdup (t);
 166
 167   d->targetv[d->ntargets++] = t;
 168 }
 169
 170 /* Sets the default target if none has been given already.  An empty
 171    string as the default target in interpreted as stdin.  The string
 172    is quoted for MAKE.  */
 173 void
 174 deps_add_default_target (struct deps *d, const char *tgt)
 175 {
 176   /* Only if we have no targets.  */
 177   if (d->ntargets)
 178     return;
 179
 180   if (tgt[0] == '\0')
 181     deps_add_target (d, "-", 1);
 182   else
 183     {
 184 #ifndef TARGET_OBJECT_SUFFIX
 185 # define TARGET_OBJECT_SUFFIX ".o"
 186 #endif
 187       const char *start = lbasename (tgt);
 188       char *o = alloca (strlen (start) + strlen (TARGET_OBJECT_SUFFIX) + 1);
 189       char *suffix;
 190
 191       strcpy (o, start);
 192
 193       suffix = strrchr (o, '.');
 194       if (!suffix)
 195         suffix = o + strlen (o);
 196       strcpy (suffix, TARGET_OBJECT_SUFFIX);
 197
 198       deps_add_target (d, o, 1);
 199     }
 200 }
 201
 202 void
 203 deps_add_dep (struct deps *d, const char *t)
 204 {
 205   t = munge (t);  /* Also makes permanent copy.  */
 206
 207   if (d->ndeps == d->deps_size)
 208     {
 209       d->deps_size = d->deps_size * 2 + 8;
 210       d->depv = xrealloc (d->depv, d->deps_size * sizeof (const char *));
 211     }
 212   d->depv[d->ndeps++] = t;
 213 }
 214
 215 void
 216 deps_write (const struct deps *d, FILE *fp, unsigned int colmax)
 217 {
 218   unsigned int size, i, column;
 219
 220   column = 0;
 221   if (colmax && colmax < 34)
 222     colmax = 34;
 223
 224   for (i = 0; i < d->ntargets; i++)
 225     {
 226       size = strlen (d->targetv[i]);
 227       column += size;
 228       if (colmax && column > colmax)
 229         {
 230           fputs (" \\\n ", fp);
 231           column = 1 + size;
 232         }
 233       if (i)
 234         {
 235           putc (' ', fp);
 236           column++;
 237         }
 238       fputs (d->targetv[i], fp);
 239     }
 240
 241   putc (':', fp);
 242   putc (' ', fp);
 243   column += 2;
 244
 245   for (i = 0; i < d->ndeps; i++)
 246     {
 247       size = strlen (d->depv[i]);
 248       column += size;
 249       if (colmax && column > colmax)
 250         {
 251           fputs (" \\\n ", fp);
 252           column = 1 + size;
 253         }
 254       if (i)
 255         {
 256           putc (' ', fp);
 257           column++;
 258         }
 259       fputs (d->depv[i], fp);
 260     }
 261   putc ('\n', fp);
 262 }
 263
 264 void
 265 deps_phony_targets (const struct deps *d, FILE *fp)
 266 {
 267   unsigned int i;
 268
 269   for (i = 1; i < d->ndeps; i++)
 270     {
 271       putc ('\n', fp);
 272       fputs (d->depv[i], fp);
 273       putc (':', fp);
 274       putc ('\n', fp);
 275     }
 276 }
 277
 278 /* Write out a deps buffer to a file, in a form that can be read back
 279    with deps_restore.  Returns nonzero on error, in which case the
 280    error number will be in errno.  */
 281
 282 int
 283 deps_save (struct deps *deps, FILE *f)
 284 {
 285   unsigned int i;
 286
 287   /* The cppreader structure contains makefile dependences.  Write out this
 288      structure.  */
 289
 290   /* The number of dependences.  */
 291   if (fwrite (&deps->ndeps, sizeof (deps->ndeps), 1, f) != 1)
 292       return -1;
 293   /* The length of each dependence followed by the string.  */
 294   for (i = 0; i < deps->ndeps; i++)
 295     {
 296       size_t num_to_write = strlen (deps->depv[i]);
 297       if (fwrite (&num_to_write, sizeof (size_t), 1, f) != 1)
 298           return -1;
 299       if (fwrite (deps->depv[i], num_to_write, 1, f) != 1)
 300           return -1;
 301     }
 302
 303   return 0;
 304 }
 305
 306 /* Read back dependency information written with deps_save into
 307    the deps buffer.  The third argument may be NULL, in which case
 308    the dependency information is just skipped, or it may be a filename,
 309    in which case that filename is skipped.  */
 310
 311 int
 312 deps_restore (struct deps *deps, FILE *fd, const char *self)
 313 {
 314   unsigned int i, count;
 315   size_t num_to_read;
 316   size_t buf_size = 512;
 317   char *buf = xmalloc (buf_size);
 318
 319   /* Number of dependences.  */
 320   if (fread (&count, 1, sizeof (count), fd) != sizeof (count))
 321     return -1;
 322
 323   /* The length of each dependence string, followed by the string.  */
 324   for (i = 0; i < count; i++)
 325     {
 326       /* Read in # bytes in string.  */
 327       if (fread (&num_to_read, 1, sizeof (size_t), fd) != sizeof (size_t))
 328         return -1;
 329       if (buf_size < num_to_read + 1)
 330         {
 331           buf_size = num_to_read + 1 + 127;
 332           buf = xrealloc (buf, buf_size);
 333         }
 334       if (fread (buf, 1, num_to_read, fd) != num_to_read)
 335         return -1;
 336       buf[num_to_read] = '\0';
 337
 338       /* Generate makefile dependencies from .pch if -nopch-deps.  */
 339       if (self != NULL && strcmp (buf, self) != 0)
 340         deps_add_dep (deps, buf);
 341     }
 342
 343   free (buf);
 344   return 0;
 345 }