misc.c

   1 /* Miscellaneous generic support functions for GNU Make.
   2 Copyright (C) 1988-2012 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 it under the
   6 terms of the GNU General Public License as published by the Free Software
   7 Foundation; either version 3 of the License, or (at your option) any later
   8 version.
   9
  10 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
  11 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  12 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License along with
  15 this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 #include "make.h"
  18 #include "dep.h"
  19 #include "debug.h"
  20
  21 /* Variadic functions.  We go through contortions to allow proper function
  22    prototypes for both ANSI and pre-ANSI C compilers, and also for those
  23    which support stdarg.h vs. varargs.h, and finally those which have
  24    vfprintf(), etc. and those who have _doprnt... or nothing.
  25
  26    This fancy stuff all came from GNU fileutils, except for the VA_PRINTF and
  27    VA_END macros used here since we have multiple print functions.  */
  28
  29 #if USE_VARIADIC
  30 # if HAVE_STDARG_H
  31 #  include <stdarg.h>
  32 #  define VA_START(args, lastarg) va_start(args, lastarg)
  33 # else
  34 #  include <varargs.h>
  35 #  define VA_START(args, lastarg) va_start(args)
  36 # endif
  37 # if HAVE_VPRINTF
  38 #  define VA_PRINTF(fp, lastarg, args) vfprintf((fp), (lastarg), (args))
  39 # else
  40 #  define VA_PRINTF(fp, lastarg, args) _doprnt((lastarg), (args), (fp))
  41 # endif
  42 # define VA_END(args) va_end(args)
  43 #else
  44 /* We can't use any variadic interface! */
  45 # define va_alist a1, a2, a3, a4, a5, a6, a7, a8
  46 # define va_dcl char *a1, *a2, *a3, *a4, *a5, *a6, *a7, *a8;
  47 # define VA_START(args, lastarg)
  48 # define VA_PRINTF(fp, lastarg, args) fprintf((fp), (lastarg), va_alist)
  49 # define VA_END(args)
  50 #endif
  51
  52
  53 /* Compare strings *S1 and *S2.
  54    Return negative if the first is less, positive if it is greater,
  55    zero if they are equal.  */
  56
  57 int
  58 alpha_compare (const void *v1, const void *v2)
  59 {
  60   const char *s1 = *((char **)v1);
  61   const char *s2 = *((char **)v2);
  62
  63   if (*s1 != *s2)
  64     return *s1 - *s2;
  65   return strcmp (s1, s2);
  66 }
  67 \f
  68 /* Discard each backslash-newline combination from LINE.
  69    Backslash-backslash-newline combinations become backslash-newlines.
  70    This is done by copying the text at LINE into itself.  */
  71
  72 void
  73 collapse_continuations (char *line)
  74 {
  75   register char *in, *out, *p;
  76   register int backslash;
  77   register unsigned int bs_write;
  78
  79   in = strchr (line, '\n');
  80   if (in == 0)
  81     return;
  82
  83   out = in;
  84   while (out > line && out[-1] == '\\')
  85     --out;
  86
  87   while (*in != '\0')
  88     {
  89       /* BS_WRITE gets the number of quoted backslashes at
  90          the end just before IN, and BACKSLASH gets nonzero
  91          if the next character is quoted.  */
  92       backslash = 0;
  93       bs_write = 0;
  94       for (p = in - 1; p >= line && *p == '\\'; --p)
  95         {
  96           if (backslash)
  97             ++bs_write;
  98           backslash = !backslash;
  99
 100           /* It should be impossible to go back this far without exiting,
 101              but if we do, we can't get the right answer.  */
 102           if (in == out - 1)
 103             abort ();
 104         }
 105
 106       /* Output the appropriate number of backslashes.  */
 107       while (bs_write-- > 0)
 108         *out++ = '\\';
 109
 110       /* Skip the newline.  */
 111       ++in;
 112
 113       if (backslash)
 114         {
 115           /* Backslash/newline handling:
 116              In traditional GNU make all trailing whitespace, consecutive
 117              backslash/newlines, and any leading whitespace on the next line
 118              is reduced to a single space.
 119              In POSIX, each backslash/newline and is replaced by a space.  */
 120           in = next_token (in);
 121           if (! posix_pedantic)
 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   unsigned 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   /* Get some more memory if we don't have enough space for the
 206      terminating '\0'.   */
 207   if (ri == rlen)
 208     {
 209       rlen = (rlen ? rlen : 60) * 2;
 210       result = xrealloc (result, rlen);
 211     }
 212
 213   result[ri] = '\0';
 214
 215   return result;
 216 }
 217 \f
 218 /* Print a message on stdout.  */
 219
 220 void
 221 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 222 message (int prefix, const char *fmt, ...)
 223 #else
 224 message (prefix, fmt, va_alist)
 225      int prefix;
 226      const char *fmt;
 227      va_dcl
 228 #endif
 229 {
 230 #if USE_VARIADIC
 231   va_list args;
 232 #endif
 233
 234   log_working_directory (1);
 235
 236   if (fmt != 0)
 237     {
 238       if (prefix)
 239         {
 240           if (makelevel == 0)
 241             printf ("%s: ", program);
 242           else
 243             printf ("%s[%u]: ", program, makelevel);
 244         }
 245       VA_START (args, fmt);
 246       VA_PRINTF (stdout, fmt, args);
 247       VA_END (args);
 248       putchar ('\n');
 249     }
 250
 251   fflush (stdout);
 252 }
 253
 254 /* Print an error message.  */
 255
 256 void
 257 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 258 error (const struct floc *flocp, const char *fmt, ...)
 259 #else
 260 error (flocp, fmt, va_alist)
 261      const struct floc *flocp;
 262      const char *fmt;
 263      va_dcl
 264 #endif
 265 {
 266 #if USE_VARIADIC
 267   va_list args;
 268 #endif
 269
 270   log_working_directory (1);
 271
 272   if (flocp && flocp->filenm)
 273     fprintf (stderr, "%s:%lu: ", flocp->filenm, flocp->lineno);
 274   else if (makelevel == 0)
 275     fprintf (stderr, "%s: ", program);
 276   else
 277     fprintf (stderr, "%s[%u]: ", program, makelevel);
 278
 279   VA_START(args, fmt);
 280   VA_PRINTF (stderr, fmt, args);
 281   VA_END (args);
 282
 283   putc ('\n', stderr);
 284   fflush (stderr);
 285 }
 286
 287 /* Print an error message and exit.  */
 288
 289 void
 290 #if HAVE_ANSI_COMPILER && USE_VARIADIC && HAVE_STDARG_H
 291 fatal (const struct floc *flocp, const char *fmt, ...)
 292 #else
 293 fatal (flocp, fmt, va_alist)
 294      const struct floc *flocp;
 295      const char *fmt;
 296      va_dcl
 297 #endif
 298 {
 299 #if USE_VARIADIC
 300   va_list args;
 301 #endif
 302
 303   log_working_directory (1);
 304
 305   if (flocp && flocp->filenm)
 306     fprintf (stderr, "%s:%lu: *** ", flocp->filenm, flocp->lineno);
 307   else if (makelevel == 0)
 308     fprintf (stderr, "%s: *** ", program);
 309   else
 310     fprintf (stderr, "%s[%u]: *** ", program, makelevel);
 311
 312   VA_START(args, fmt);
 313   VA_PRINTF (stderr, fmt, args);
 314   VA_END (args);
 315
 316   fputs (_(".  Stop.\n"), stderr);
 317
 318   die (2);
 319 }
 320
 321 #ifndef HAVE_STRERROR
 322
 323 #undef  strerror
 324
 325 char *
 326 strerror (int errnum)
 327 {
 328   extern int errno, sys_nerr;
 329 #ifndef __DECC
 330   extern char *sys_errlist[];
 331 #endif
 332   static char buf[] = "Unknown error 12345678901234567890";
 333
 334   if (errno < sys_nerr)
 335     return sys_errlist[errnum];
 336
 337   sprintf (buf, _("Unknown error %d"), errnum);
 338   return buf;
 339 }
 340 #endif
 341
 342 /* Print an error message from errno.  */
 343
 344 void
 345 perror_with_name (const char *str, const char *name)
 346 {
 347   error (NILF, _("%s%s: %s"), str, name, strerror (errno));
 348 }
 349
 350 /* Print an error message from errno and exit.  */
 351
 352 void
 353 pfatal_with_name (const char *name)
 354 {
 355   fatal (NILF, _("%s: %s"), name, strerror (errno));
 356
 357   /* NOTREACHED */
 358 }
 359 \f
 360 /* Like malloc but get fatal error if memory is exhausted.  */
 361 /* Don't bother if we're using dmalloc; it provides these for us.  */
 362
 363 #ifndef HAVE_DMALLOC_H
 364
 365 #undef xmalloc
 366 #undef xcalloc
 367 #undef xrealloc
 368 #undef xstrdup
 369
 370 void *
 371 xmalloc (unsigned int size)
 372 {
 373   /* Make sure we don't allocate 0, for pre-ISO implementations.  */
 374   void *result = malloc (size ? size : 1);
 375   if (result == 0)
 376     fatal (NILF, _("virtual memory exhausted"));
 377   return result;
 378 }
 379
 380
 381 void *
 382 xcalloc (unsigned int size)
 383 {
 384   /* Make sure we don't allocate 0, for pre-ISO implementations.  */
 385   void *result = calloc (size ? size : 1, 1);
 386   if (result == 0)
 387     fatal (NILF, _("virtual memory exhausted"));
 388   return result;
 389 }
 390
 391
 392 void *
 393 xrealloc (void *ptr, unsigned int size)
 394 {
 395   void *result;
 396
 397   /* Some older implementations of realloc() don't conform to ISO.  */
 398   if (! size)
 399     size = 1;
 400   result = ptr ? realloc (ptr, size) : malloc (size);
 401   if (result == 0)
 402     fatal (NILF, _("virtual memory exhausted"));
 403   return result;
 404 }
 405
 406
 407 char *
 408 xstrdup (const char *ptr)
 409 {
 410   char *result;
 411
 412 #ifdef HAVE_STRDUP
 413   result = strdup (ptr);
 414 #else
 415   result = malloc (strlen (ptr) + 1);
 416 #endif
 417
 418   if (result == 0)
 419     fatal (NILF, _("virtual memory exhausted"));
 420
 421 #ifdef HAVE_STRDUP
 422   return result;
 423 #else
 424   return strcpy (result, ptr);
 425 #endif
 426 }
 427
 428 #endif  /* HAVE_DMALLOC_H */
 429
 430 char *
 431 xstrndup (const char *str, unsigned int length)
 432 {
 433   char *result;
 434
 435 #ifdef HAVE_STRNDUP
 436   result = strndup (str, length);
 437   if (result == 0)
 438     fatal (NILF, _("virtual memory exhausted"));
 439 #else
 440   result = xmalloc (length + 1);
 441   if (length > 0)
 442     strncpy (result, str, length);
 443   result[length] = '\0';
 444 #endif
 445
 446   return result;
 447 }
 448 \f
 449
 450 /* Limited INDEX:
 451    Search through the string STRING, which ends at LIMIT, for the character C.
 452    Returns a pointer to the first occurrence, or nil if none is found.
 453    Like INDEX except that the string searched ends where specified
 454    instead of at the first null.  */
 455
 456 char *
 457 lindex (const char *s, const char *limit, int c)
 458 {
 459   while (s < limit)
 460     if (*s++ == c)
 461       return (char *)(s - 1);
 462
 463   return 0;
 464 }
 465 \f
 466 /* Return the address of the first whitespace or null in the string S.  */
 467
 468 char *
 469 end_of_token (const char *s)
 470 {
 471   while (*s != '\0' && !isblank ((unsigned char)*s))
 472     ++s;
 473   return (char *)s;
 474 }
 475
 476 #ifdef WINDOWS32
 477 /*
 478  * Same as end_of_token, but take into account a stop character
 479  */
 480 char *
 481 end_of_token_w32 (const char *s, char stopchar)
 482 {
 483   const char *p = s;
 484   int backslash = 0;
 485
 486   while (*p != '\0' && *p != stopchar
 487          && (backslash || !isblank ((unsigned char)*p)))
 488     {
 489       if (*p++ == '\\')
 490         {
 491           backslash = !backslash;
 492           while (*p == '\\')
 493             {
 494               backslash = !backslash;
 495               ++p;
 496             }
 497         }
 498       else
 499         backslash = 0;
 500     }
 501
 502   return (char *)p;
 503 }
 504 #endif
 505
 506 /* Return the address of the first nonwhitespace or null in the string S.  */
 507
 508 char *
 509 next_token (const char *s)
 510 {
 511   while (isblank ((unsigned char)*s))
 512     ++s;
 513   return (char *)s;
 514 }
 515
 516 /* Find the next token in PTR; return the address of it, and store the length
 517    of the token into *LENGTHPTR if LENGTHPTR is not nil.  Set *PTR to the end
 518    of the token, so this function can be called repeatedly in a loop.  */
 519
 520 char *
 521 find_next_token (const char **ptr, unsigned int *lengthptr)
 522 {
 523   const char *p = next_token (*ptr);
 524
 525   if (*p == '\0')
 526     return 0;
 527
 528   *ptr = end_of_token (p);
 529   if (lengthptr != 0)
 530     *lengthptr = *ptr - p;
 531
 532   return (char *)p;
 533 }
 534 \f
 535
 536 /* Copy a chain of 'struct dep'.  For 2nd expansion deps, dup the name.  */
 537
 538 struct dep *
 539 copy_dep_chain (const struct dep *d)
 540 {
 541   struct dep *firstnew = 0;
 542   struct dep *lastnew = 0;
 543
 544   while (d != 0)
 545     {
 546       struct dep *c = xmalloc (sizeof (struct dep));
 547       memcpy (c, d, sizeof (struct dep));
 548
 549       if (c->need_2nd_expansion)
 550         c->name = xstrdup (c->name);
 551
 552       c->next = 0;
 553       if (firstnew == 0)
 554         firstnew = lastnew = c;
 555       else
 556         lastnew = lastnew->next = c;
 557
 558       d = d->next;
 559     }
 560
 561   return firstnew;
 562 }
 563
 564 /* Free a chain of 'struct dep'.  */
 565
 566 void
 567 free_dep_chain (struct dep *d)
 568 {
 569   while (d != 0)
 570     {
 571       struct dep *df = d;
 572       d = d->next;
 573       free_dep (df);
 574     }
 575 }
 576
 577 /* Free a chain of struct nameseq.
 578    For struct dep chains use free_dep_chain.  */
 579
 580 void
 581 free_ns_chain (struct nameseq *ns)
 582 {
 583   while (ns != 0)
 584     {
 585       struct nameseq *t = ns;
 586       ns = ns->next;
 587       free (t);
 588     }
 589 }
 590 \f
 591
 592 #if !HAVE_STRCASECMP && !HAVE_STRICMP && !HAVE_STRCMPI
 593
 594 /* If we don't have strcasecmp() (from POSIX), or anything that can substitute
 595    for it, define our own version.  */
 596
 597 int
 598 strcasecmp (const char *s1, const char *s2)
 599 {
 600   while (1)
 601     {
 602       int c1 = (int) *(s1++);
 603       int c2 = (int) *(s2++);
 604
 605       if (isalpha (c1))
 606         c1 = tolower (c1);
 607       if (isalpha (c2))
 608         c2 = tolower (c2);
 609
 610       if (c1 != '\0' && c1 == c2)
 611         continue;
 612
 613       return (c1 - c2);
 614     }
 615 }
 616 #endif
 617
 618 #if !HAVE_STRNCASECMP && !HAVE_STRNICMP && !HAVE_STRNCMPI
 619
 620 /* If we don't have strncasecmp() (from POSIX), or anything that can
 621    substitute for it, define our own version.  */
 622
 623 int
 624 strncasecmp (const char *s1, const char *s2, int n)
 625 {
 626   while (n-- > 0)
 627     {
 628       int c1 = (int) *(s1++);
 629       int c2 = (int) *(s2++);
 630
 631       if (isalpha (c1))
 632         c1 = tolower (c1);
 633       if (isalpha (c2))
 634         c2 = tolower (c2);
 635
 636       if (c1 != '\0' && c1 == c2)
 637         continue;
 638
 639       return (c1 - c2);
 640     }
 641
 642   return 0;
 643 }
 644 #endif
 645 \f
 646 #ifdef  GETLOADAVG_PRIVILEGED
 647
 648 #ifdef POSIX
 649
 650 /* Hopefully if a system says it's POSIX.1 and has the setuid and setgid
 651    functions, they work as POSIX.1 says.  Some systems (Alpha OSF/1 1.2,
 652    for example) which claim to be POSIX.1 also have the BSD setreuid and
 653    setregid functions, but they don't work as in BSD and only the POSIX.1
 654    way works.  */
 655
 656 #undef HAVE_SETREUID
 657 #undef HAVE_SETREGID
 658
 659 #else   /* Not POSIX.  */
 660
 661 /* Some POSIX.1 systems have the seteuid and setegid functions.  In a
 662    POSIX-like system, they are the best thing to use.  However, some
 663    non-POSIX systems have them too but they do not work in the POSIX style
 664    and we must use setreuid and setregid instead.  */
 665
 666 #undef HAVE_SETEUID
 667 #undef HAVE_SETEGID
 668
 669 #endif  /* POSIX.  */
 670
 671 #ifndef HAVE_UNISTD_H
 672 extern int getuid (), getgid (), geteuid (), getegid ();
 673 extern int setuid (), setgid ();
 674 #ifdef HAVE_SETEUID
 675 extern int seteuid ();
 676 #else
 677 #ifdef  HAVE_SETREUID
 678 extern int setreuid ();
 679 #endif  /* Have setreuid.  */
 680 #endif  /* Have seteuid.  */
 681 #ifdef HAVE_SETEGID
 682 extern int setegid ();
 683 #else
 684 #ifdef  HAVE_SETREGID
 685 extern int setregid ();
 686 #endif  /* Have setregid.  */
 687 #endif  /* Have setegid.  */
 688 #endif  /* No <unistd.h>.  */
 689
 690 /* Keep track of the user and group IDs for user- and make- access.  */
 691 static int user_uid = -1, user_gid = -1, make_uid = -1, make_gid = -1;
 692 #define access_inited   (user_uid != -1)
 693 static enum { make, user } current_access;
 694
 695
 696 /* Under -d, write a message describing the current IDs.  */
 697
 698 static void
 699 log_access (const char *flavor)
 700 {
 701   if (! ISDB (DB_JOBS))
 702     return;
 703
 704   /* All the other debugging messages go to stdout,
 705      but we write this one to stderr because it might be
 706      run in a child fork whose stdout is piped.  */
 707
 708   fprintf (stderr, _("%s: user %lu (real %lu), group %lu (real %lu)\n"),
 709            flavor, (unsigned long) geteuid (), (unsigned long) getuid (),
 710            (unsigned long) getegid (), (unsigned long) getgid ());
 711   fflush (stderr);
 712 }
 713
 714
 715 static void
 716 init_access (void)
 717 {
 718 #ifndef VMS
 719   user_uid = getuid ();
 720   user_gid = getgid ();
 721
 722   make_uid = geteuid ();
 723   make_gid = getegid ();
 724
 725   /* Do these ever fail?  */
 726   if (user_uid == -1 || user_gid == -1 || make_uid == -1 || make_gid == -1)
 727     pfatal_with_name ("get{e}[gu]id");
 728
 729   log_access (_("Initialized access"));
 730
 731   current_access = make;
 732 #endif
 733 }
 734
 735 #endif  /* GETLOADAVG_PRIVILEGED */
 736
 737 /* Give the process appropriate permissions for access to
 738    user data (i.e., to stat files, or to spawn a child process).  */
 739 void
 740 user_access (void)
 741 {
 742 #ifdef  GETLOADAVG_PRIVILEGED
 743
 744   if (!access_inited)
 745     init_access ();
 746
 747   if (current_access == user)
 748     return;
 749
 750   /* We are in "make access" mode.  This means that the effective user and
 751      group IDs are those of make (if it was installed setuid or setgid).
 752      We now want to set the effective user and group IDs to the real IDs,
 753      which are the IDs of the process that exec'd make.  */
 754
 755 #ifdef  HAVE_SETEUID
 756
 757   /* Modern systems have the seteuid/setegid calls which set only the
 758      effective IDs, which is ideal.  */
 759
 760   if (seteuid (user_uid) < 0)
 761     pfatal_with_name ("user_access: seteuid");
 762
 763 #else   /* Not HAVE_SETEUID.  */
 764
 765 #ifndef HAVE_SETREUID
 766
 767   /* System V has only the setuid/setgid calls to set user/group IDs.
 768      There is an effective ID, which can be set by setuid/setgid.
 769      It can be set (unless you are root) only to either what it already is
 770      (returned by geteuid/getegid, now in make_uid/make_gid),
 771      the real ID (return by getuid/getgid, now in user_uid/user_gid),
 772      or the saved set ID (what the effective ID was before this set-ID
 773      executable (make) was exec'd).  */
 774
 775   if (setuid (user_uid) < 0)
 776     pfatal_with_name ("user_access: setuid");
 777
 778 #else   /* HAVE_SETREUID.  */
 779
 780   /* In 4BSD, the setreuid/setregid calls set both the real and effective IDs.
 781      They may be set to themselves or each other.  So you have two alternatives
 782      at any one time.  If you use setuid/setgid, the effective will be set to
 783      the real, leaving only one alternative.  Using setreuid/setregid, however,
 784      you can toggle between your two alternatives by swapping the values in a
 785      single setreuid or setregid call.  */
 786
 787   if (setreuid (make_uid, user_uid) < 0)
 788     pfatal_with_name ("user_access: setreuid");
 789
 790 #endif  /* Not HAVE_SETREUID.  */
 791 #endif  /* HAVE_SETEUID.  */
 792
 793 #ifdef  HAVE_SETEGID
 794   if (setegid (user_gid) < 0)
 795     pfatal_with_name ("user_access: setegid");
 796 #else
 797 #ifndef HAVE_SETREGID
 798   if (setgid (user_gid) < 0)
 799     pfatal_with_name ("user_access: setgid");
 800 #else
 801   if (setregid (make_gid, user_gid) < 0)
 802     pfatal_with_name ("user_access: setregid");
 803 #endif
 804 #endif
 805
 806   current_access = user;
 807
 808   log_access (_("User access"));
 809
 810 #endif  /* GETLOADAVG_PRIVILEGED */
 811 }
 812
 813 /* Give the process appropriate permissions for access to
 814    make data (i.e., the load average).  */
 815 void
 816 make_access (void)
 817 {
 818 #ifdef  GETLOADAVG_PRIVILEGED
 819
 820   if (!access_inited)
 821     init_access ();
 822
 823   if (current_access == make)
 824     return;
 825
 826   /* See comments in user_access, above.  */
 827
 828 #ifdef  HAVE_SETEUID
 829   if (seteuid (make_uid) < 0)
 830     pfatal_with_name ("make_access: seteuid");
 831 #else
 832 #ifndef HAVE_SETREUID
 833   if (setuid (make_uid) < 0)
 834     pfatal_with_name ("make_access: setuid");
 835 #else
 836   if (setreuid (user_uid, make_uid) < 0)
 837     pfatal_with_name ("make_access: setreuid");
 838 #endif
 839 #endif
 840
 841 #ifdef  HAVE_SETEGID
 842   if (setegid (make_gid) < 0)
 843     pfatal_with_name ("make_access: setegid");
 844 #else
 845 #ifndef HAVE_SETREGID
 846   if (setgid (make_gid) < 0)
 847     pfatal_with_name ("make_access: setgid");
 848 #else
 849   if (setregid (user_gid, make_gid) < 0)
 850     pfatal_with_name ("make_access: setregid");
 851 #endif
 852 #endif
 853
 854   current_access = make;
 855
 856   log_access (_("Make access"));
 857
 858 #endif  /* GETLOADAVG_PRIVILEGED */
 859 }
 860
 861 /* Give the process appropriate permissions for a child process.
 862    This is like user_access, but you can't get back to make_access.  */
 863 void
 864 child_access (void)
 865 {
 866 #ifdef  GETLOADAVG_PRIVILEGED
 867
 868   if (!access_inited)
 869     abort ();
 870
 871   /* Set both the real and effective UID and GID to the user's.
 872      They cannot be changed back to make's.  */
 873
 874 #ifndef HAVE_SETREUID
 875   if (setuid (user_uid) < 0)
 876     pfatal_with_name ("child_access: setuid");
 877 #else
 878   if (setreuid (user_uid, user_uid) < 0)
 879     pfatal_with_name ("child_access: setreuid");
 880 #endif
 881
 882 #ifndef HAVE_SETREGID
 883   if (setgid (user_gid) < 0)
 884     pfatal_with_name ("child_access: setgid");
 885 #else
 886   if (setregid (user_gid, user_gid) < 0)
 887     pfatal_with_name ("child_access: setregid");
 888 #endif
 889
 890   log_access (_("Child access"));
 891
 892 #endif  /* GETLOADAVG_PRIVILEGED */
 893 }
 894 \f
 895 #ifdef NEED_GET_PATH_MAX
 896 unsigned int
 897 get_path_max (void)
 898 {
 899   static unsigned int value;
 900
 901   if (value == 0)
 902     {
 903       long int x = pathconf ("/", _PC_PATH_MAX);
 904       if (x > 0)
 905         value = x;
 906       else
 907         return MAXPATHLEN;
 908     }
 909
 910   return value;
 911 }
 912 #endif
 913 \f
 914
 915 /* This code is stolen from gnulib.
 916    If/when we abandon the requirement to work with K&R compilers, we can
 917    remove this (and perhaps other parts of GNU make!) and migrate to using
 918    gnulib directly.
 919
 920    This is called only through atexit(), which means die() has already been
 921    invoked.  So, call exit() here directly.  Apparently that works...?
 922 */
 923
 924 /* Close standard output, exiting with status 'exit_failure' on failure.
 925    If a program writes *anything* to stdout, that program should close
 926    stdout and make sure that it succeeds before exiting.  Otherwise,
 927    suppose that you go to the extreme of checking the return status
 928    of every function that does an explicit write to stdout.  The last
 929    printf can succeed in writing to the internal stream buffer, and yet
 930    the fclose(stdout) could still fail (due e.g., to a disk full error)
 931    when it tries to write out that buffered data.  Thus, you would be
 932    left with an incomplete output file and the offending program would
 933    exit successfully.  Even calling fflush is not always sufficient,
 934    since some file systems (NFS and CODA) buffer written/flushed data
 935    until an actual close call.
 936
 937    Besides, it's wasteful to check the return value from every call
 938    that writes to stdout -- just let the internal stream state record
 939    the failure.  That's what the ferror test is checking below.
 940
 941    It's important to detect such failures and exit nonzero because many
 942    tools (most notably 'make' and other build-management systems) depend
 943    on being able to detect failure in other tools via their exit status.  */
 944
 945 void
 946 close_stdout (void)
 947 {
 948   int prev_fail = ferror (stdout);
 949   int fclose_fail = fclose (stdout);
 950
 951   if (prev_fail || fclose_fail)
 952     {
 953       if (fclose_fail)
 954         error (NILF, _("write error: %s"), strerror (errno));
 955       else
 956         error (NILF, _("write error"));
 957       exit (EXIT_FAILURE);
 958     }
 959 }