src/s/gnu-linux.h

   1 /* This file is the configuration file for Linux-based GNU systems
   2
   3 Copyright (C) 1985-1986, 1992, 1994, 1996, 1999, 2001-2012
   4   Free Software Foundation, Inc.
   5
   6 This file was put together by Michael K. Johnson and Rik Faith.
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software: you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation, either version 3 of the License, or
  13 (at your option) any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 /* Define symbols to identify the version of Unix this is.
  24    Define all the symbols that apply correctly.  */
  25 #define USG
  26 #define GNU_LINUX
  27
  28 #if defined HAVE_GRANTPT
  29 #define UNIX98_PTYS
  30
  31 #ifdef HAVE_GETPT
  32 #define PTY_NAME_SPRINTF
  33 #define PTY_OPEN fd = getpt ()
  34 #else /* not HAVE_GETPT */
  35 #define PTY_NAME_SPRINTF strcpy (pty_name, "/dev/ptmx");
  36 #endif /* not HAVE_GETPT */
  37
  38 /* Note that grantpt and unlockpt may fork.  We must block SIGCHLD to
  39    prevent sigchld_handler from intercepting the child's death.  */
  40 #define PTY_TTY_NAME_SPRINTF                            \
  41   {                                                     \
  42     char *ptyname;                                      \
  43                                                         \
  44     sigblock (sigmask (SIGCHLD));                       \
  45     if (grantpt (fd) == -1 || unlockpt (fd) == -1       \
  46         || !(ptyname = ptsname(fd)))                    \
  47       {                                                 \
  48         sigunblock (sigmask (SIGCHLD));                 \
  49         close (fd);                                     \
  50         return -1;                                      \
  51       }                                                 \
  52     snprintf (pty_name, sizeof pty_name, "%s", ptyname); \
  53     sigunblock (sigmask (SIGCHLD));                     \
  54   }
  55
  56 #endif  /* HAVE_GRANTPT */
  57
  58 /* Here, on a separate page, add any special hacks needed
  59    to make Emacs work on this system.  For example,
  60    you might define certain system call names that don't
  61    exist on your system, or that do different things on
  62    your system and must be used only through an encapsulation
  63    (Which you should place, by convention, in sysdep.c).  */
  64 \f
  65
  66 /* This is to work around mysterious gcc failures in some system versions.
  67    It is unlikely that Emacs changes will work around this problem;
  68    therefore, this should remain permanently.  */
  69 #ifndef HAVE_XRMSETDATABASE
  70 #define HAVE_XRMSETDATABASE
  71 #endif
  72
  73 #ifdef __ia64__
  74 #define GC_MARK_SECONDARY_STACK()                               \
  75   do {                                                          \
  76     extern void *__libc_ia64_register_backing_store_base;       \
  77     __builtin_ia64_flushrs ();                                  \
  78     mark_memory (__libc_ia64_register_backing_store_base,       \
  79                  __builtin_ia64_bsp ());                        \
  80   } while (0)
  81 #endif
  82
  83 /* Tell that garbage collector that setjmp is known to save all
  84    registers relevant for conservative garbage collection in the jmp_buf.
  85    Not all the architectures are tested, but there are Debian packages
  86    for SCM and/or Guile on them, so the technique must work.  See also
  87    comments in alloc.c concerning setjmp and gcc.  Fixme:  it's
  88    probably safe to just let the GCC conditional in AH_BOTTOM handle this.
  89 */
  90 #if defined __i386__ || defined __sparc__ || defined __mc68000__ \
  91     || defined __alpha__ || defined __mips__ || defined __s390__ \
  92     || defined __arm__ || defined __powerpc__ || defined __amd64__ \
  93     || defined __ia64__ || defined __sh__
  94 #define GC_SETJMP_WORKS 1
  95 #else
  96 #define GC_MARK_STACK GC_USE_GCPROS_AS_BEFORE
  97 #endif
  98
  99 #ifdef __i386__
 100 /* libc-linux/sysdeps/linux/i386/ulimit.c says that due to shared library, */
 101 /* we cannot get the maximum address for brk */
 102 # define ULIMIT_BREAK_VALUE (32*1024*1024)
 103 #endif