misc.c

   1 /* Miscellaneous generic support functions for GNU Make.
   2 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
   3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software
   4 Foundation, Inc.
   5 This file is part of GNU Make.
   6
   7 GNU Make is free software; you can redistribute it and/or modify it under the
   8 terms of the GNU General Public License as published by the Free Software
   9 Foundation; either version 3 of the License, or (at your option) any later
  10 version.
  11
  12 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  14 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License along with
  17 this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "make.h"
  20 #include "dep.h"
  21 #include "debug.h"
  22
  23 /* Variadic functions.  We go through contortions to allow proper function
  24    prototypes for both ANSI and pre-ANSI C compilers, and also for those
  25    which support stdarg.h vs. varargs.h, and finally those which have
  26    vfprintf(), etc. and those who have _doprnt... or nothing.
  27
  28    This fancy stuff all came from GNU fileutils, except for the VA_PRINTF and
  29    VA_END macros used here since we have multiple print functions.  */
  30
  31 #if USE_VARIADIC
  32 # if HAVE_STDARG_H
  33 #  include <stdarg.h>
  34 #  define VA_START(args, lastarg) va_start(args, lastarg)
  35 # else
  36 #  include <varargs.h>
  37 #  define VA_START(args, lastarg) va_start(args)
  38 # endif
  39 # if HAVE_VPRINTF
  40 #  define VA_PRINTF(fp, lastarg, args) vfprintf((fp), (lastarg), (args))
  41 # else
  42 #  define VA_PRINTF(fp, lastarg, args) _doprnt((lastarg), (args), (fp))
  43 # endif
  44 # define VA_END(args) va_end(args)
  45 #else
  46 /* We can't use any variadic interface! */
  47 # define va_alist a1, a2, a3, a4, a5, a6, a7, a8
  48 # define va_dcl char *a1, *a2, *a3, *a4, *a5, *a6, *a7, *a8;
  49 # define VA_START(args, lastarg)
  50 # define VA_PRINTF(fp, lastarg, args) fprintf((fp), (lastarg), va_alist)
  51 # define VA_END(args)
  52 #endif
  53
  54
  55 /* Compare strings *S1 and *S2.
  56    Return negative if the first is less, positive if it is greater,
  57    zero if they are equal.  */
  58
  59 int
  60 alpha_compare (const void *v1, const void *v2)
  61 {
  62   const char *s1 = *((char **)v1);
  63   const char *s2 = *((char **)v2);
  64
  65   if (*s1 != *s2)
  66     return *s1 - *s2;
  67   return strcmp (s1, s2);
  68 }
  69 \f
  70 /* Discard each backslash-newline combination from LINE.
  71    Backslash-backslash-newline combinations become backslash-newlines.
  72    This is done by copying the text at LINE into itself.  */
  73
  74 void
  75 collapse_continuations (char *line)
  76 {
  77   register char *in, *out, *p;
  78   register int backslash;
  79   register unsigned int bs_write;
  80
  81   in = strchr (line, '\n');
  82   if (in == 0)
  83     return;
  84
  85   out = in;
  86   while (out > line && out[-1] == '\\')
  87     --out;
  88
  89   while (*in != '\0')
  90     {
  91       /* BS_WRITE gets the number of quoted backslashes at
  92          the end just before IN, and BACKSLASH gets nonzero
  93          if the next character is quoted.  */
  94       backslash = 0;
  95       bs_write = 0;
  96       for (p = in - 1; p >= line && *p == '\\'; --p)
  97         {
  98           if (backslash)
  99             ++bs_write;
 100           backslash = !backslash;
 101
 102           /* It should be impossible to go back this far without exiting,
 103              but if we do, we can't get the right answer.  */
 104           if (in == out - 1)
 105             abort ();
 106         }
 107
 108       /* Output the appropriate number of backslashes.  */
 109       while (bs_write-- > 0)
 110         *out++ = '\\';
 111
 112       /* Skip the newline.  */
 113       ++in;
 114
 115       /* If the newline is escaped, discard following whitespace leaving just
 116          one space.  POSIX requires that each backslash/newline/following
 117          whitespace sequence be reduced to a single space.  */
 118       if (backslash)
 119         {
 120           in = next_token (in);
 121           /* Removing this loop will fix Savannah bug #16670: do we want to? */
 122           while (out > line && isblank ((unsigned char)out[-1]))
 123             --out;
 124           *out++ = ' ';
 125         }
 126       else
 127         /* If the newline isn't quoted, put it in the output.  */
 128         *out++ = '\n';
 129
 130       /* Now copy the following line to the output.
 131          Stop when we find backslashes followed by a newline.  */
 132       while (*in != '\0')
 133         if (*in == '\\')
 134           {
 135             p = in + 1;
 136             while (*p == '\\')
 137               ++p;
 138             if (*p == '\n')
 139               {
 140                 in = p;
 141                 break;
 142               }
 143             while (in < p)
 144               *out++ = *in++;
 145           }
 146         else
 147           *out++ = *in++;
 148     }
 149
 150   *out = '\0';
 151 }
 152 \f
 153 /* Print N spaces (used in debug for target-depth).  */
 154
 155 void
 156 print_spaces (unsigned int n)
 157 {
 158   while (n-- > 0)
 159     putchar (' ');
 160 }
 161
 162 \f
 163 /* Return a string whose contents concatenate the NUM strings provided
 164    This string lives in static, re-used memory.  */
 165
 166 const char *
 167 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 168 concat (unsigned int num, ...)
 169 #else
 170 concat (num, va_alist)
 171      unsigned int num;
 172      va_dcl
 173 #endif
 174 {
 175   static unsigned int rlen = 0;
 176   static char *result = NULL;
 177   int ri = 0;
 178
 179 #if USE_VARIADIC
 180   va_list args;
 181 #endif
 182
 183   VA_START (args, num);
 184
 185   while (num-- > 0)
 186     {
 187       const char *s = va_arg (args, const char *);
 188       unsigned int l = s ? strlen (s) : 0;
 189
 190       if (l == 0)
 191         continue;
 192
 193       if (ri + l > rlen)
 194         {
 195           rlen = ((rlen ? rlen : 60) + l) * 2;
 196           result = xrealloc (result, rlen);
 197         }
 198
 199       memcpy (result + ri, s, l);
 200       ri += l;
 201     }
 202
 203   VA_END (args);
 204
 205   result[ri] = '\0';
 206
 207   return result;
 208 }
 209 \f
 210 /* Print a message on stdout.  */
 211
 212 void
 213 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 214 message (int prefix, const char *fmt, ...)
 215 #else
 216 message (prefix, fmt, va_alist)
 217      int prefix;
 218      const char *fmt;
 219      va_dcl
 220 #endif
 221 {
 222 #if USE_VARIADIC
 223   va_list args;
 224 #endif
 225
 226   log_working_directory (1);
 227
 228   if (fmt != 0)
 229     {
 230       if (prefix)
 231         {
 232           if (makelevel == 0)
 233             printf ("%s: ", program);
 234           else
 235             printf ("%s[%u]: ", program, makelevel);
 236         }
 237       VA_START (args, fmt);
 238       VA_PRINTF (stdout, fmt, args);
 239       VA_END (args);
 240       putchar ('\n');
 241     }
 242
 243   fflush (stdout);
 244 }
 245
 246 /* Print an error message.  */
 247
 248 void
 249 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 250 error (const struct floc *flocp, const char *fmt, ...)
 251 #else
 252 error (flocp, fmt, va_alist)
 253      const struct floc *flocp;
 254      const char *fmt;
 255      va_dcl
 256 #endif
 257 {
 258 #if USE_VARIADIC
 259   va_list args;
 260 #endif
 261
 262   log_working_directory (1);
 263
 264   if (flocp && flocp->filenm)
 265     fprintf (stderr, "%s:%lu: ", flocp->filenm, flocp->lineno);
 266   else if (makelevel == 0)
 267     fprintf (stderr, "%s: ", program);
 268   else
 269     fprintf (stderr, "%s[%u]: ", program, makelevel);
 270
 271   VA_START(args, fmt);
 272   VA_PRINTF (stderr, fmt, args);
 273   VA_END (args);
 274
 275   putc ('\n', stderr);
 276   fflush (stderr);
 277 }
 278
 279 /* Print an error message and exit.  */
 280
 281 void
 282 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 283 fatal (const struct floc *flocp, const char *fmt, ...)
 284 #else
 285 fatal (flocp, fmt, va_alist)
 286      const struct floc *flocp;
 287      const char *fmt;
 288      va_dcl
 289 #endif
 290 {
 291 #if USE_VARIADIC
 292   va_list args;
 293 #endif
 294
 295   log_working_directory (1);
 296
 297   if (flocp && flocp->filenm)
 298     fprintf (stderr, "%s:%lu: *** ", flocp->filenm, flocp->lineno);
 299   else if (makelevel == 0)
 300     fprintf (stderr, "%s: *** ", program);
 301   else
 302     fprintf (stderr, "%s[%u]: *** ", program, makelevel);
 303
 304   VA_START(args, fmt);
 305   VA_PRINTF (stderr, fmt, args);
 306   VA_END (args);
 307
 308   fputs (_(".  Stop.\n"), stderr);
 309
 310   die (2);
 311 }
 312
 313 #ifndef HAVE_STRERROR
 314
 315 #undef  strerror
 316
 317 char *
 318 strerror (int errnum)
 319 {
 320   extern int errno, sys_nerr;
 321 #ifndef __DECC
 322   extern char *sys_errlist[];
 323 #endif
 324   static char buf[] = "Unknown error 12345678901234567890";
 325
 326   if (errno < sys_nerr)
 327     return sys_errlist[errnum];
 328
 329   sprintf (buf, _("Unknown error %d"), errnum);
 330   return buf;
 331 }
 332 #endif
 333
 334 /* Print an error message from errno.  */
 335
 336 void
 337 perror_with_name (const char *str, const char *name)
 338 {
 339   error (NILF, _("%s%s: %s"), str, name, strerror (errno));
 340 }
 341
 342 /* Print an error message from errno and exit.  */
 343
 344 void
 345 pfatal_with_name (const char *name)
 346 {
 347   fatal (NILF, _("%s: %s"), name, strerror (errno));
 348
 349   /* NOTREACHED */
 350 }
 351 \f
 352 /* Like malloc but get fatal error if memory is exhausted.  */
 353 /* Don't bother if we're using dmalloc; it provides these for us.  */
 354
 355 #ifndef HAVE_DMALLOC_H
 356
 357 #undef xmalloc
 358 #undef xcalloc
 359 #undef xrealloc
 360 #undef xstrdup
 361
 362 void *
 363 xmalloc (unsigned int size)
 364 {
 365   /* Make sure we don't allocate 0, for pre-ISO implementations.  */
 366   void *result = malloc (size ? size : 1);
 367   if (result == 0)
 368     fatal (NILF, _("virtual memory exhausted"));
 369   return result;
 370 }
 371
 372
 373 void *
 374 xcalloc (unsigned int size)
 375 {
 376   /* Make sure we don't allocate 0, for pre-ISO implementations.  */
 377   void *result = calloc (size ? size : 1, 1);
 378   if (result == 0)
 379     fatal (NILF, _("virtual memory exhausted"));
 380   return result;
 381 }
 382
 383
 384 void *
 385 xrealloc (void *ptr, unsigned int size)
 386 {
 387   void *result;
 388
 389   /* Some older implementations of realloc() don't conform to ISO.  */
 390   if (! size)
 391     size = 1;
 392   result = ptr ? realloc (ptr, size) : malloc (size);
 393   if (result == 0)
 394     fatal (NILF, _("virtual memory exhausted"));
 395   return result;
 396 }
 397
 398
 399 char *
 400 xstrdup (const char *ptr)
 401 {
 402   char *result;
 403
 404 #ifdef HAVE_STRDUP
 405   result = strdup (ptr);
 406 #else
 407   result = malloc (strlen (ptr) + 1);
 408 #endif
 409
 410   if (result == 0)
 411     fatal (NILF, _("virtual memory exhausted"));
 412
 413 #ifdef HAVE_STRDUP
 414   return result;
 415 #else
 416   return strcpy (result, ptr);
 417 #endif
 418 }
 419
 420 #endif  /* HAVE_DMALLOC_H */
 421
 422 char *
 423 xstrndup (const char *str, unsigned int length)
 424 {
 425   char *result;
 426
 427 #ifdef HAVE_STRNDUP
 428   result = strndup (str, length);
 429   if (result == 0)
 430     fatal (NILF, _("virtual memory exhausted"));
 431 #else
 432   result = xmalloc (length + 1);
 433   strncpy (result, str, length);
 434   result[length] = '\0';
 435 #endif
 436
 437   return result;
 438 }
 439 \f
 440
 441 /* Limited INDEX:
 442    Search through the string STRING, which ends at LIMIT, for the character C.
 443    Returns a pointer to the first occurrence, or nil if none is found.
 444    Like INDEX except that the string searched ends where specified
 445    instead of at the first null.  */
 446
 447 char *
 448 lindex (const char *s, const char *limit, int c)
 449 {
 450   while (s < limit)
 451     if (*s++ == c)
 452       return (char *)(s - 1);
 453
 454   return 0;
 455 }
 456 \f
 457 /* Return the address of the first whitespace or null in the string S.  */
 458
 459 char *
 460 end_of_token (const char *s)
 461 {
 462   while (*s != '\0' && !isblank ((unsigned char)*s))
 463     ++s;
 464   return (char *)s;
 465 }
 466
 467 #ifdef WINDOWS32
 468 /*
 469  * Same as end_of_token, but take into account a stop character
 470  */
 471 char *
 472 end_of_token_w32 (const char *s, char stopchar)
 473 {
 474   const char *p = s;
 475   int backslash = 0;
 476
 477   while (*p != '\0' && *p != stopchar
 478          && (backslash || !isblank ((unsigned char)*p)))
 479     {
 480       if (*p++ == '\\')
 481         {
 482           backslash = !backslash;
 483           while (*p == '\\')
 484             {
 485               backslash = !backslash;
 486               ++p;
 487             }
 488         }
 489       else
 490         backslash = 0;
 491     }
 492
 493   return (char *)p;
 494 }
 495 #endif
 496
 497 /* Return the address of the first nonwhitespace or null in the string S.  */
 498
 499 char *
 500 next_token (const char *s)
 501 {
 502   while (isblank ((unsigned char)*s))
 503     ++s;
 504   return (char *)s;
 505 }
 506
 507 /* Find the next token in PTR; return the address of it, and store the length
 508    of the token into *LENGTHPTR if LENGTHPTR is not nil.  Set *PTR to the end
 509    of the token, so this function can be called repeatedly in a loop.  */
 510
 511 char *
 512 find_next_token (const char **ptr, unsigned int *lengthptr)
 513 {
 514   const char *p = next_token (*ptr);
 515
 516   if (*p == '\0')
 517     return 0;
 518
 519   *ptr = end_of_token (p);
 520   if (lengthptr != 0)
 521     *lengthptr = *ptr - p;
 522
 523   return (char *)p;
 524 }
 525 \f
 526
 527 /* Copy a chain of `struct dep', making a new chain
 528    with the same contents as the old one.  */
 529
 530 struct dep *
 531 copy_dep_chain (const struct dep *d)
 532 {
 533   struct dep *firstnew = 0;
 534   struct dep *lastnew = 0;
 535
 536   while (d != 0)
 537     {
 538       struct dep *c = xmalloc (sizeof (struct dep));
 539       memcpy (c, d, sizeof (struct dep));
 540
 541       c->next = 0;
 542       if (firstnew == 0)
 543         firstnew = lastnew = c;
 544       else
 545         lastnew = lastnew->next = c;
 546
 547       d = d->next;
 548     }
 549
 550   return firstnew;
 551 }
 552
 553 /* Free a chain of 'struct dep'.  */
 554
 555 void
 556 free_dep_chain (struct dep *d)
 557 {
 558   while (d != 0)
 559     {
 560       struct dep *df = d;
 561       d = d->next;
 562       free_dep (df);
 563     }
 564 }
 565
 566 /* Free a chain of struct nameseq.
 567    For struct dep chains use free_dep_chain.  */
 568
 569 void
 570 free_ns_chain (struct nameseq *ns)
 571 {
 572   while (ns != 0)
 573     {
 574       struct nameseq *t = ns;
 575       ns = ns->next;
 576       free (t);
 577     }
 578 }
 579 \f
 580
 581 #if !HAVE_STRCASECMP && !HAVE_STRICMP && !HAVE_STRCMPI
 582
 583 /* If we don't have strcasecmp() (from POSIX), or anything that can substitute
 584    for it, define our own version.  */
 585
 586 int
 587 strcasecmp (const char *s1, const char *s2)
 588 {
 589   while (1)
 590     {
 591       int c1 = (int) *(s1++);
 592       int c2 = (int) *(s2++);
 593
 594       if (isalpha (c1))
 595         c1 = tolower (c1);
 596       if (isalpha (c2))
 597         c2 = tolower (c2);
 598
 599       if (c1 != '\0' && c1 == c2)
 600         continue;
 601
 602       return (c1 - c2);
 603     }
 604 }
 605 #endif
 606 \f
 607 #ifdef  GETLOADAVG_PRIVILEGED
 608
 609 #ifdef POSIX
 610
 611 /* Hopefully if a system says it's POSIX.1 and has the setuid and setgid
 612    functions, they work as POSIX.1 says.  Some systems (Alpha OSF/1 1.2,
 613    for example) which claim to be POSIX.1 also have the BSD setreuid and
 614    setregid functions, but they don't work as in BSD and only the POSIX.1
 615    way works.  */
 616
 617 #undef HAVE_SETREUID
 618 #undef HAVE_SETREGID
 619
 620 #else   /* Not POSIX.  */
 621
 622 /* Some POSIX.1 systems have the seteuid and setegid functions.  In a
 623    POSIX-like system, they are the best thing to use.  However, some
 624    non-POSIX systems have them too but they do not work in the POSIX style
 625    and we must use setreuid and setregid instead.  */
 626
 627 #undef HAVE_SETEUID
 628 #undef HAVE_SETEGID
 629
 630 #endif  /* POSIX.  */
 631
 632 #ifndef HAVE_UNISTD_H
 633 extern int getuid (), getgid (), geteuid (), getegid ();
 634 extern int setuid (), setgid ();
 635 #ifdef HAVE_SETEUID
 636 extern int seteuid ();
 637 #else
 638 #ifdef  HAVE_SETREUID
 639 extern int setreuid ();
 640 #endif  /* Have setreuid.  */
 641 #endif  /* Have seteuid.  */
 642 #ifdef HAVE_SETEGID
 643 extern int setegid ();
 644 #else
 645 #ifdef  HAVE_SETREGID
 646 extern int setregid ();
 647 #endif  /* Have setregid.  */
 648 #endif  /* Have setegid.  */
 649 #endif  /* No <unistd.h>.  */
 650
 651 /* Keep track of the user and group IDs for user- and make- access.  */
 652 static int user_uid = -1, user_gid = -1, make_uid = -1, make_gid = -1;
 653 #define access_inited   (user_uid != -1)
 654 static enum { make, user } current_access;
 655
 656
 657 /* Under -d, write a message describing the current IDs.  */
 658
 659 static void
 660 log_access (const char *flavor)
 661 {
 662   if (! ISDB (DB_JOBS))
 663     return;
 664
 665   /* All the other debugging messages go to stdout,
 666      but we write this one to stderr because it might be
 667      run in a child fork whose stdout is piped.  */
 668
 669   fprintf (stderr, _("%s: user %lu (real %lu), group %lu (real %lu)\n"),
 670            flavor, (unsigned long) geteuid (), (unsigned long) getuid (),
 671            (unsigned long) getegid (), (unsigned long) getgid ());
 672   fflush (stderr);
 673 }
 674
 675
 676 static void
 677 init_access (void)
 678 {
 679 #ifndef VMS
 680   user_uid = getuid ();
 681   user_gid = getgid ();
 682
 683   make_uid = geteuid ();
 684   make_gid = getegid ();
 685
 686   /* Do these ever fail?  */
 687   if (user_uid == -1 || user_gid == -1 || make_uid == -1 || make_gid == -1)
 688     pfatal_with_name ("get{e}[gu]id");
 689
 690   log_access (_("Initialized access"));
 691
 692   current_access = make;
 693 #endif
 694 }
 695
 696 #endif  /* GETLOADAVG_PRIVILEGED */
 697
 698 /* Give the process appropriate permissions for access to
 699    user data (i.e., to stat files, or to spawn a child process).  */
 700 void
 701 user_access (void)
 702 {
 703 #ifdef  GETLOADAVG_PRIVILEGED
 704
 705   if (!access_inited)
 706     init_access ();
 707
 708   if (current_access == user)
 709     return;
 710
 711   /* We are in "make access" mode.  This means that the effective user and
 712      group IDs are those of make (if it was installed setuid or setgid).
 713      We now want to set the effective user and group IDs to the real IDs,
 714      which are the IDs of the process that exec'd make.  */
 715
 716 #ifdef  HAVE_SETEUID
 717
 718   /* Modern systems have the seteuid/setegid calls which set only the
 719      effective IDs, which is ideal.  */
 720
 721   if (seteuid (user_uid) < 0)
 722     pfatal_with_name ("user_access: seteuid");
 723
 724 #else   /* Not HAVE_SETEUID.  */
 725
 726 #ifndef HAVE_SETREUID
 727
 728   /* System V has only the setuid/setgid calls to set user/group IDs.
 729      There is an effective ID, which can be set by setuid/setgid.
 730      It can be set (unless you are root) only to either what it already is
 731      (returned by geteuid/getegid, now in make_uid/make_gid),
 732      the real ID (return by getuid/getgid, now in user_uid/user_gid),
 733      or the saved set ID (what the effective ID was before this set-ID
 734      executable (make) was exec'd).  */
 735
 736   if (setuid (user_uid) < 0)
 737     pfatal_with_name ("user_access: setuid");
 738
 739 #else   /* HAVE_SETREUID.  */
 740
 741   /* In 4BSD, the setreuid/setregid calls set both the real and effective IDs.
 742      They may be set to themselves or each other.  So you have two alternatives
 743      at any one time.  If you use setuid/setgid, the effective will be set to
 744      the real, leaving only one alternative.  Using setreuid/setregid, however,
 745      you can toggle between your two alternatives by swapping the values in a
 746      single setreuid or setregid call.  */
 747
 748   if (setreuid (make_uid, user_uid) < 0)
 749     pfatal_with_name ("user_access: setreuid");
 750
 751 #endif  /* Not HAVE_SETREUID.  */
 752 #endif  /* HAVE_SETEUID.  */
 753
 754 #ifdef  HAVE_SETEGID
 755   if (setegid (user_gid) < 0)
 756     pfatal_with_name ("user_access: setegid");
 757 #else
 758 #ifndef HAVE_SETREGID
 759   if (setgid (user_gid) < 0)
 760     pfatal_with_name ("user_access: setgid");
 761 #else
 762   if (setregid (make_gid, user_gid) < 0)
 763     pfatal_with_name ("user_access: setregid");
 764 #endif
 765 #endif
 766
 767   current_access = user;
 768
 769   log_access (_("User access"));
 770
 771 #endif  /* GETLOADAVG_PRIVILEGED */
 772 }
 773
 774 /* Give the process appropriate permissions for access to
 775    make data (i.e., the load average).  */
 776 void
 777 make_access (void)
 778 {
 779 #ifdef  GETLOADAVG_PRIVILEGED
 780
 781   if (!access_inited)
 782     init_access ();
 783
 784   if (current_access == make)
 785     return;
 786
 787   /* See comments in user_access, above.  */
 788
 789 #ifdef  HAVE_SETEUID
 790   if (seteuid (make_uid) < 0)
 791     pfatal_with_name ("make_access: seteuid");
 792 #else
 793 #ifndef HAVE_SETREUID
 794   if (setuid (make_uid) < 0)
 795     pfatal_with_name ("make_access: setuid");
 796 #else
 797   if (setreuid (user_uid, make_uid) < 0)
 798     pfatal_with_name ("make_access: setreuid");
 799 #endif
 800 #endif
 801
 802 #ifdef  HAVE_SETEGID
 803   if (setegid (make_gid) < 0)
 804     pfatal_with_name ("make_access: setegid");
 805 #else
 806 #ifndef HAVE_SETREGID
 807   if (setgid (make_gid) < 0)
 808     pfatal_with_name ("make_access: setgid");
 809 #else
 810   if (setregid (user_gid, make_gid) < 0)
 811     pfatal_with_name ("make_access: setregid");
 812 #endif
 813 #endif
 814
 815   current_access = make;
 816
 817   log_access (_("Make access"));
 818
 819 #endif  /* GETLOADAVG_PRIVILEGED */
 820 }
 821
 822 /* Give the process appropriate permissions for a child process.
 823    This is like user_access, but you can't get back to make_access.  */
 824 void
 825 child_access (void)
 826 {
 827 #ifdef  GETLOADAVG_PRIVILEGED
 828
 829   if (!access_inited)
 830     abort ();
 831
 832   /* Set both the real and effective UID and GID to the user's.
 833      They cannot be changed back to make's.  */
 834
 835 #ifndef HAVE_SETREUID
 836   if (setuid (user_uid) < 0)
 837     pfatal_with_name ("child_access: setuid");
 838 #else
 839   if (setreuid (user_uid, user_uid) < 0)
 840     pfatal_with_name ("child_access: setreuid");
 841 #endif
 842
 843 #ifndef HAVE_SETREGID
 844   if (setgid (user_gid) < 0)
 845     pfatal_with_name ("child_access: setgid");
 846 #else
 847   if (setregid (user_gid, user_gid) < 0)
 848     pfatal_with_name ("child_access: setregid");
 849 #endif
 850
 851   log_access (_("Child access"));
 852
 853 #endif  /* GETLOADAVG_PRIVILEGED */
 854 }
 855 \f
 856 #ifdef NEED_GET_PATH_MAX
 857 unsigned int
 858 get_path_max (void)
 859 {
 860   static unsigned int value;
 861
 862   if (value == 0)
 863     {
 864       long int x = pathconf ("/", _PC_PATH_MAX);
 865       if (x > 0)
 866         value = x;
 867       else
 868         return MAXPATHLEN;
 869     }
 870
 871   return value;
 872 }
 873 #endif
 874 \f
 875
 876 /* This code is stolen from gnulib.
 877    If/when we abandon the requirement to work with K&R compilers, we can
 878    remove this (and perhaps other parts of GNU make!) and migrate to using
 879    gnulib directly.
 880
 881    This is called only through atexit(), which means die() has already been
 882    invoked.  So, call exit() here directly.  Apparently that works...?
 883 */
 884
 885 /* Close standard output, exiting with status 'exit_failure' on failure.
 886    If a program writes *anything* to stdout, that program should close
 887    stdout and make sure that it succeeds before exiting.  Otherwise,
 888    suppose that you go to the extreme of checking the return status
 889    of every function that does an explicit write to stdout.  The last
 890    printf can succeed in writing to the internal stream buffer, and yet
 891    the fclose(stdout) could still fail (due e.g., to a disk full error)
 892    when it tries to write out that buffered data.  Thus, you would be
 893    left with an incomplete output file and the offending program would
 894    exit successfully.  Even calling fflush is not always sufficient,
 895    since some file systems (NFS and CODA) buffer written/flushed data
 896    until an actual close call.
 897
 898    Besides, it's wasteful to check the return value from every call
 899    that writes to stdout -- just let the internal stream state record
 900    the failure.  That's what the ferror test is checking below.
 901
 902    It's important to detect such failures and exit nonzero because many
 903    tools (most notably `make' and other build-management systems) depend
 904    on being able to detect failure in other tools via their exit status.  */
 905
 906 void
 907 close_stdout (void)
 908 {
 909   int prev_fail = ferror (stdout);
 910   int fclose_fail = fclose (stdout);
 911
 912   if (prev_fail || fclose_fail)
 913     {
 914       if (fclose_fail)
 915         error (NILF, _("write error: %s"), strerror (errno));
 916       else
 917         error (NILF, _("write error"));
 918       exit (EXIT_FAILURE);
 919     }
 920 }