Remove support for IRIX

The IRIX port wasn’t really working anyway, and the code was
getting in the way of other changes (e.g., getaddrinfo fixes).
IRIX’s supplier dropped support for IRIX in 2013.
* admin/CPP-DEFINES:
* configure.ac (opsys):
* doc/lispref/os.texi (System Environment):
* etc/MACHINES, etc/PROBLEMS:
* lisp/find-dired.el (find-grep-options):
* lisp/lpr.el (lpr-lp-system):
* lisp/ls-lisp.el (ls-lisp-emulation):
* lisp/mail/rmail.el (rmail-spool-directory):
* lisp/net/net-utils.el (ping-program-options):
* lisp/progmodes/gud.el (gud-irix-p, gud-dbx-use-stopformat-p):
* lisp/progmodes/ps-mode.el (ps-mode-print-function):
* src/conf_post.h [IRIX6_5]:
* src/emacs.c (Vsystem_type):
* src/filelock.c (get_boot_time_1):
* src/process.c (process_send_signal):
* src/unexelf.c (unexec):
Omit IRIX-specific code and/or documentation.
* configure.ac (NON_GCC_TEST_OPTIONS, IRIX6_5, PREFER_VSUSP):
Remove.  All uses removed.
* etc/NEWS: Document the change.

18 files changed, 30 insertions, 162 deletions

diff --git a/admin/CPP-DEFINES b/admin/CPP-DEFINES
index 86f2fa5a41..9064053934 100644
--- a/admin/CPP-DEFINES
+++ b/admin/CPP-DEFINES
@@ -13,7 +13,6 @@ CYGWIN		Compiling the Cygwin port.
 __CYGWIN__	Ditto
 GNU_LINUX
 HPUX
-IRIX6_5
 MSDOS		Compiling the MS-DOS port.
 __MSDOS__	Ditto.
 __DJGPP_MINOR__ Minor version number of the DJGPP library; used only in msdos.c and dosfns.c.
@@ -378,7 +377,6 @@ NSIG
 NSIG_MINIMUM
 NULL_DEVICE
 PAGESIZE
-PREFER_VSUSP
 PTY_ITERATION
 PTY_NAME_SPRINTF
 PTY_OPEN
diff --git a/configure.ac b/configure.ac
index 0de6736aee..61287d74ca 100644
--- a/configure.ac
+++ b/configure.ac
@@ -615,12 +615,7 @@ case "${canonical}" in
       * )            unported=yes ;;
     esac
     opsys=darwin
-    ## Use fink packages if available.
-    ## FIXME find a better way to do this: http://debbugs.gnu.org/11507
-##    if test -d /sw/include && test -d /sw/lib; then
-##      GCC_TEST_OPTIONS="-I/sw/include -L/sw/lib"
-##      NON_GCC_TEST_OPTIONS=${GCC_TEST_OPTIONS}
-##    fi
+    ## FIXME: Find a way to use Fink if available (Bug#11507).
   ;;
 
   ## Chromium Native Client
@@ -656,16 +651,6 @@ case "${canonical}" in
     opsys=aix4-2
   ;;
 
-  ## Silicon Graphics machines
-  ## Iris 4D
-  mips-sgi-irix6.5 )
-    opsys=irix6-5
-    # Without defining _LANGUAGE_C, things get masked out in the headers
-    # so that, for instance, grepping for 'free' in stdlib.h fails and
-    # AC_HEADER_STD_C fails.   (MIPSPro 7.2.1.2m compilers, Irix 6.5.3m).
-    NON_GCC_TEST_OPTIONS="-D_LANGUAGE_C"
-  ;;
-
   ## Suns
   *-sun-solaris* \
     | i[3456]86-*-solaris2* | i[3456]86-*-sunos5* \
@@ -782,8 +767,6 @@ AM_PROG_CC_C_O
 
 if test x$GCC = xyes; then
   test "x$GCC_TEST_OPTIONS" != x && CC="$CC $GCC_TEST_OPTIONS"
-else
-  test "x$NON_GCC_TEST_OPTIONS" != x && CC="$CC $NON_GCC_TEST_OPTIONS"
 fi
 
 dnl This is used in lib/Makefile.am to use nt/gnulib.mk, the
@@ -1233,7 +1216,6 @@ fi
 
 dnl We need -znocombreloc if we're using a relatively recent GNU ld.
 dnl If we can link with the flag, it shouldn't do any harm anyhow.
-dnl (Don't use '-z nocombreloc' as -z takes no arg on Irix.)
 dnl Treat GCC specially since it just gives a non-fatal 'unrecognized option'
 dnl if not built to support GNU ld.
 
@@ -1462,7 +1444,7 @@ LIBS=$OLD_LIBS
 
 dnl Current possibilities handled by sed (aix4-2 -> aix,
 dnl gnu-linux -> gnu/linux, etc.):
-dnl gnu, gnu/linux, gnu/kfreebsd, aix, cygwin, darwin, hpux, irix.
+dnl gnu, gnu/linux, gnu/kfreebsd, aix, cygwin, darwin, hpux.
 dnl And special cases: berkeley-unix, usg-unix-v, ms-dos, windows-nt.
 SYSTEM_TYPE=`echo $opsys | sed -e 's/[[0-9]].*//' -e 's|-|/|'`
 
@@ -2199,7 +2181,7 @@ fi
 
 use_mmap_for_buffers=no
 case "$opsys" in
-  cygwin|mingw32|irix6-5) use_mmap_for_buffers=yes ;;
+  cygwin|mingw32) use_mmap_for_buffers=yes ;;
 esac
 
 AC_FUNC_MMAP
@@ -3776,7 +3758,7 @@ mail_lock=no
 case "$opsys" in
   aix4-2) mail_lock="lockf" ;;
 
-  gnu|freebsd|dragonfly|netbsd|openbsd|darwin|irix6-5) mail_lock="flock" ;;
+  gnu|freebsd|dragonfly|netbsd|openbsd|darwin) mail_lock="flock" ;;
 
   ## On GNU/Linux systems, both methods are used by various mail programs.
   ## I assume most people are using newer mailers that have heard of flock.
@@ -4286,7 +4268,7 @@ esac
 
 
 case $opsys in
-  irix6-5 | sol2* | unixware )
+  sol2* | unixware )
     dnl Some SVr4s don't define NSIG in sys/signal.h for ANSI environments;
     dnl instead, there's a system variable _sys_nsig.  Unfortunately, we
     dnl need the constant to dimension an array.  So wire in the appropriate
@@ -4300,7 +4282,7 @@ emacs_broken_SIGIO=no
 case $opsys in
   dnl SIGIO exists, but the feature doesn't work in the way Emacs needs.
   dnl See eg <http://article.gmane.org/gmane.os.openbsd.ports/46831>.
-  hpux* | irix6-5 | nacl | openbsd | sol2* | unixware )
+  hpux* | nacl | openbsd | sol2* | unixware )
     emacs_broken_SIGIO=yes
     ;;
 
@@ -4408,7 +4390,7 @@ dnl generated in the Makefile generated by 'xmkmf'.  If we don't define
 dnl NARROWPROTO, we will see the wrong function prototypes for X functions
 dnl taking float or double parameters.
 case $opsys in
-  cygwin|gnu|gnu-linux|gnu-kfreebsd|irix6-5|freebsd|netbsd|openbsd)
+  cygwin|gnu|gnu-linux|gnu-kfreebsd|freebsd|netbsd|openbsd)
     AC_DEFINE(NARROWPROTO, 1, [Define if system's imake configuration
       file defines 'NeedWidePrototypes' as 'NO'.])
   ;;
@@ -4416,7 +4398,6 @@ esac
 
 
 dnl Used in process.c, this must be a loop, even if it only runs once.
-dnl (Except on SGI; see below.  Take that, clarity and consistency!)
 AH_TEMPLATE(PTY_ITERATION, [How to iterate over PTYs.])
 dnl Only used if !PTY_ITERATION.  Iterate from FIRST_PTY_LETTER to z,
 dnl trying suffixes 0-16.
@@ -4479,27 +4460,6 @@ case $opsys in
     AC_DEFINE(PTY_TTY_NAME_SPRINTF, [sprintf (pty_name, "/dev/pty/tty%c%x", c, i);])
     ;;
 
-  irix6-5 )
-    dnl It looks like this cannot be right, because it is not a loop.
-    dnl However, process.c actually does this:
-    dnl # ifndef __sgi
-    dnl   continue;
-    dnl # else
-    dnl   return -1;
-    dnl # endif
-    dnl which presumably makes it OK, since irix == sgi (?).
-    dnl FIXME it seems like this special treatment is unnecessary?
-    dnl Why can't irix use a single-trip loop like eg cygwin?
-    AC_DEFINE(PTY_ITERATION, [])
-    dnl Not used, because PTY_ITERATION is defined.
-    AC_DEFINE(FIRST_PTY_LETTER, ['q'])
-    AC_DEFINE(PTY_OPEN, [ { struct sigaction ocstat, cstat; struct stat stb; char * name; sigemptyset(&cstat.sa_mask); cstat.sa_handler = SIG_DFL; cstat.sa_flags = 0; sigaction(SIGCHLD, &cstat, &ocstat); name = _getpty (&fd, O_RDWR | O_NDELAY, 0600, 0); sigaction(SIGCHLD, &ocstat, (struct sigaction *)0); if (name == 0) return -1; if (fd < 0) return -1; if (fstat (fd, &stb) < 0) return -1; strcpy (pty_name, name); }])
-    dnl No need to get the pty name at all.
-    AC_DEFINE(PTY_NAME_SPRINTF, [])
-    dnl No need to use sprintf to get the tty name--we get that from _getpty.
-    AC_DEFINE(PTY_TTY_NAME_SPRINTF, [])
-    ;;
-
   sol2* )
     dnl On SysVr4, grantpt(3) forks a subprocess, so do not use
     dnl O_CLOEXEC when opening the pty, and keep the SIGCHLD handler
@@ -4534,8 +4494,7 @@ AH_TEMPLATE(SIGNALS_VIA_CHARACTERS, [Make process_send_signal work by
 
 case $opsys in
   dnl Perry Smith <pedz@ddivt1.austin.ibm.com> says this is correct for AIX.
-  dnl thomas@mathematik.uni-bremen.de says this is needed for IRIX.
-  aix4-2 | cygwin | gnu | irix6-5 | dragonfly | freebsd | netbsd | openbsd | darwin )
+  aix4-2 | cygwin | gnu | dragonfly | freebsd | netbsd | openbsd | darwin )
     AC_DEFINE(SIGNALS_VIA_CHARACTERS, 1)
     ;;
 
@@ -4615,8 +4574,7 @@ if test x$GCC = xyes; then
    AC_DEFINE(GC_SETJMP_WORKS, 1)
 else
   case $opsys in
-    dnl irix: Tested on Irix 6.5.  SCM worked on earlier versions.
-    aix* | dragonfly | freebsd | netbsd | openbsd | irix6-5 | sol2* )
+    aix* | dragonfly | freebsd | netbsd | openbsd | sol2* )
       AC_DEFINE(GC_SETJMP_WORKS, 1)
       ;;
   esac
@@ -4720,12 +4678,6 @@ case $opsys in
     AC_DEFINE(HPUX, [], [Define if the system is HPUX.])
     ;;
 
-  irix6-5)
-    AC_DEFINE(USG, [])
-    AC_DEFINE(USG5_4, [])
-    AC_DEFINE(IRIX6_5, [], [Define if the system is IRIX.])
-    ;;
-
   mingw32)
     AC_DEFINE(DOS_NT, [])
     AC_DEFINE(WINDOWSNT, 1, [Define if compiling for native MS Windows.])
@@ -4799,11 +4751,6 @@ case $opsys in
       reopen it in the child.])
     ;;
 
-  irix6-5)
-    AC_DEFINE(PREFER_VSUSP, 1, [Define if process_send_signal should
-      use VSUSP instead of VSWTCH.])
-    ;;
-
   sol2-10)
     AC_DEFINE(_STRUCTURED_PROC, 1, [Needed for system_process_attributes
       on Solaris.])
diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index d57cbcfeb9..3428c2973f 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -899,9 +899,6 @@ A GNU (glibc-based) system with a FreeBSD kernel.
 @item hpux
 Hewlett-Packard HPUX operating system.
 
-@item irix
-Silicon Graphics Irix system.
-
 @item nacl
 Google Native Client (@acronym{NaCl}) sandboxing system.
 
diff --git a/etc/MACHINES b/etc/MACHINES
index 085f169e85..5562dc2603 100644
--- a/etc/MACHINES
+++ b/etc/MACHINES
@@ -105,12 +105,10 @@ the list at the end of this file.
 
   Emacs versions later than 24.4 will not compile on Irix by default.
   (Note that SGI stopped supporting Irix in December 2013.)
-  You should be able to work around the problem either by porting the
-  Emacs undumping code to GCC under Irix, or by configuring --with-wide-int.
   Older versions of Emacs 24 (and 23?) also had problems on Irix.
   It *may* be possible to build Emacs <= 24.4 on Irix 6.5 with an old
   version (3.1) of gcc.  Newer versions of gcc may not work.
-  See <http://debbugs.gnu.org/9684>.
+  See <http://bugs.gnu.org/9684>.
 
 
 * Obsolete platforms
diff --git a/etc/NEWS b/etc/NEWS
index 92d69d2ccd..4328761cf3 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -34,6 +34,9 @@ emacs-version and erc-cmd-SV functions, and the leave the following
 variables nil: emacs-build-system, emacs-build-time,
 erc-emacs-build-time.
 
+** Emacs no longer works on IRIX.  We expect that Emacs users are not
+affected by this, as SGI stopped supporting IRIX in December 2013.
+
 
 * Startup Changes in Emacs 25.2
 
diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 7d780371d4..f61921a656 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -544,26 +544,6 @@ Other systems allow to set LD_RUN_PATH in a similar way, but before
 Emacs is linked.  With LD_RUN_PATH set, the linker will include a
 specified run-time search path in the executable.
 
-On some systems, Emacs can crash due to problems with dynamic
-linking.  Specifically, on SGI Irix 6.5, crashes were reported with
-backtraces like this:
-
-  (dbx) where
-   0 strcmp(0xf49239d, 0x4031184, 0x40302b4, 0x12, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2) ["/xlv22/ficus-jan23/work/irix/lib/libc/libc_n32_M3_ns/strings/strcmp.s":35, 0xfb7e480]
-   1 general_find_symbol(0xf49239d, 0x0, 0x0, 0x0, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2)
- ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":2140, 0xfb65a98]
-   2 resolve_symbol(0xf49239d, 0x4031184, 0x0, 0xfbdd438, 0x0, 0xf4923aa, 0x0, 0x492ddb2)
- ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":1947, 0xfb657e4]
-   3 lazy_text_resolve(0xd18, 0x1a3, 0x40302b4, 0x12, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2)
- ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":997, 0xfb64d44]
-   4 _rld_text_resolve(0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
- ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld_bridge.s":175, 0xfb6032c]
-
-('rld' is the dynamic linker.)  We don't know why this
-happens, but setting the environment variable LD_BIND_NOW to 1 (which
-forces the dynamic linker to bind all shared objects early on) seems
-to work around the problem.
-
 Please refer to the documentation of your dynamic linker for details.
 
 *** When you run Ispell from Emacs, it reports a "misalignment" error.
@@ -1931,14 +1911,6 @@ This seems to be a GCC optimization bug that occurs for GCC 4.1.2 (-g
 and -g -O2) and GCC 4.2.3 (-g -O and -g -O2).  You can fix this by
 compiling with GCC 4.2.3 or CC 5.7, with no optimizations.
 
-** Irix
-
-*** Irix: Trouble using ptys, or running out of ptys.
-
-The program mkpts (which may be in '/usr/adm' or '/usr/sbin') needs to
-be set-UID to root, or non-root programs like Emacs will not be able
-to allocate ptys reliably.
-
 * Runtime problems specific to MS-Windows
 
 ** Emacs on Windows 9X requires UNICOWS.DLL
diff --git a/lisp/find-dired.el b/lisp/find-dired.el
index 7bfdbe7346..b1b33ac23e 100644
--- a/lisp/find-dired.el
+++ b/lisp/find-dired.el
@@ -97,7 +97,7 @@ them for `find-ls-option'."
 
 (defcustom find-grep-options
   (if (or (eq system-type 'berkeley-unix)
-	  (string-match "solaris2\\|irix" system-configuration))
+	  (string-match "solaris2" system-configuration))
       "-s" "-q")
   "Option to grep to be as silent as possible.
 On Berkeley systems, this is `-s'; on Posix, and with GNU grep, `-q' does it.
diff --git a/lisp/lpr.el b/lisp/lpr.el
index 04e3b38ab1..2fe32c7d5e 100644
--- a/lisp/lpr.el
+++ b/lisp/lpr.el
@@ -36,7 +36,7 @@
 
 ;;;###autoload
 (defvar lpr-lp-system
-  (memq system-type '(usg-unix-v hpux irix))
+  (memq system-type '(usg-unix-v hpux))
   "Non-nil if running on a system type that uses the \"lp\" command.")
 
 
diff --git a/lisp/ls-lisp.el b/lisp/ls-lisp.el
index 85e91cdadc..11cbea0b37 100644
--- a/lisp/ls-lisp.el
+++ b/lisp/ls-lisp.el
@@ -72,7 +72,7 @@
 
 (defcustom ls-lisp-emulation
   (cond ;; ((eq system-type 'windows-nt) 'MS-Windows)
-	((memq system-type '(hpux usg-unix-v irix berkeley-unix))
+	((memq system-type '(hpux usg-unix-v berkeley-unix))
 	 'UNIX))	; very similar to GNU
   ;; Anything else defaults to nil, meaning GNU.
   "Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 5464c38af7..2790c89097 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -163,7 +163,7 @@ its character representation and its display representation.")
 (put 'rmail-spool-directory 'standard-value
      '((cond ((file-exists-p "/var/mail") "/var/mail/")
 	     ((file-exists-p "/var/spool/mail") "/var/spool/mail/")
-	     ((memq system-type '(hpux usg-unix-v irix)) "/usr/mail/")
+	     ((memq system-type '(hpux usg-unix-v)) "/usr/mail/")
 	     (t "/usr/spool/mail/"))))
 
 ;;;###autoload
@@ -176,7 +176,7 @@ its character representation and its display representation.")
 	 "/var/mail/")
 	;; Many GNU/Linux systems use this name.
 	((file-exists-p "/var/spool/mail") "/var/spool/mail/")
-	((memq system-type '(hpux usg-unix-v irix)) "/usr/mail/")
+	((memq system-type '(hpux usg-unix-v)) "/usr/mail/")
 	(t "/usr/spool/mail/")))
   "Name of directory used by system mailer for delivering new mail.
 Its name should end with a slash."
diff --git a/lisp/net/net-utils.el b/lisp/net/net-utils.el
index 8029e2ca70..b13bece391 100644
--- a/lisp/net/net-utils.el
+++ b/lisp/net/net-utils.el
@@ -79,7 +79,7 @@
 ;; On GNU/Linux and Irix, the system's ping program seems to send packets
 ;; indefinitely unless told otherwise
 (defcustom ping-program-options
-  (and (memq system-type '(gnu/linux irix))
+  (and (eq system-type 'gnu/linux)
        (list "-c" "4"))
   "Options for the ping program.
 These options can be used to limit how many ICMP packets are emitted."
diff --git a/lisp/progmodes/gud.el b/lisp/progmodes/gud.el
index 356cd3e053..9bf739463e 100644
--- a/lisp/progmodes/gud.el
+++ b/lisp/progmodes/gud.el
@@ -1182,36 +1182,30 @@ containing the executable being debugged."
 ;; correct line number, but life's too short.
 ;;   d.love@dl.ac.uk (Dave Love) can be blamed for this
 
-(defvar gud-irix-p
-  (and (string-match "^mips-[^-]*-irix" system-configuration)
-       (not (string-match "irix[6-9]\\.[1-9]" system-configuration)))
+(defvar gud-irix-p nil
   "Non-nil to assume the interface appropriate for IRIX dbx.
 This works in IRIX 4, 5 and 6, but `gud-dbx-use-stopformat-p' provides
 a better solution in 6.1 upwards.")
-(defvar gud-dbx-use-stopformat-p
-  (string-match "irix[6-9]\\.[1-9]" system-configuration)
+(defvar gud-dbx-use-stopformat-p nil
   "Non-nil to use the dbx feature present at least from Irix 6.1
 whereby $stopformat=1 produces an output format compatible with
 `gud-dbx-marker-filter'.")
-;; [Irix dbx seems to be a moving target.  The dbx output changed
+;; [Irix dbx seemed to be a moving target.  The dbx output changed
 ;; subtly sometime between OS v4.0.5 and v5.2 so that, for instance,
 ;; the output from `up' is no longer spotted by gud (and it's probably
 ;; not distinctive enough to try to match it -- use C-<, C->
 ;; exclusively) .  For 5.3 and 6.0, the $curline variable changed to
 ;; `long long'(why?!), so the printf stuff needed changing.  The line
 ;; number was cast to `long' as a compromise between the new `long
-;; long' and the original `int'.  This is reported not to work in 6.2,
+;; long' and the original `int'.  This was reported not to work in 6.2,
 ;; so it's changed back to int -- don't make your sources too long.
-;; From Irix6.1 (but not 6.0?) dbx supports an undocumented feature
+;; From Irix6.1 (but not 6.0?) dbx supported an undocumented feature
 ;; whereby `set $stopformat=1' reportedly produces output compatible
 ;; with `gud-dbx-marker-filter', which we prefer.
 
 ;; The process filter is also somewhat
 ;; unreliable, sometimes not spotting the markers; I don't know
-;; whether there's anything that can be done about that.  It would be
-;; much better if SGI could be persuaded to (re?)instate the MIPS
-;; -emacs flag for gdb-like output (which ought to be possible as most
-;; of the communication I've had over it has been from sgi.com).]
+;; whether there's anything that can be done about that.]
 
 ;; this filter is influenced by the xdb one rather than the gdb one
 (defun gud-irixdbx-marker-filter (string)
diff --git a/lisp/progmodes/ps-mode.el b/lisp/progmodes/ps-mode.el
index 79c32c62a5..c9299055a4 100644
--- a/lisp/progmodes/ps-mode.el
+++ b/lisp/progmodes/ps-mode.el
@@ -113,7 +113,7 @@ When the figure is finished these values should be replaced."
 (defcustom ps-mode-print-function
   (lambda ()
      (let ((lpr-switches nil)
-	   (lpr-command (if (memq system-type '(usg-unix-v hpux irix))
+	   (lpr-command (if (memq system-type '(usg-unix-v hpux))
 			    "lp" "lpr")))
        (lpr-buffer)))
   "Lisp function to print current buffer as PostScript."
diff --git a/src/conf_post.h b/src/conf_post.h
index 2788abf58a..11dbb6e81a 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -117,14 +117,6 @@ typedef bool bool_bf;
 #undef HAVE_RINT
 #endif  /* HPUX */
 
-#ifdef IRIX6_5
-#ifdef emacs
-char *_getpty();
-#endif
-#define INET6 /* Needed for struct sockaddr_in6.  */
-#undef HAVE_GETADDRINFO /* IRIX has getaddrinfo but not struct addrinfo.  */
-#endif /* IRIX6_5 */
-
 #ifdef MSDOS
 #ifndef __DJGPP__
 You lose; /* Emacs for DOS must be compiled with DJGPP */
diff --git a/src/emacs.c b/src/emacs.c
index a381da4fb8..cdc4ebbe43 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -2419,8 +2419,8 @@ Special values:
   `ms-dos'       compiled as an MS-DOS application.
   `windows-nt'   compiled as a native W32 application.
   `cygwin'       compiled using the Cygwin library.
-Anything else (in Emacs 24.1, the possibilities are: aix, berkeley-unix,
-hpux, irix, usg-unix-v) indicates some sort of Unix system.  */);
+Anything else (in Emacs 26, the possibilities are: aix, berkeley-unix,
+hpux, usg-unix-v) indicates some sort of Unix system.  */);
   Vsystem_type = intern_c_string (SYSTEM_TYPE);
   /* See configure.ac for the possible SYSTEM_TYPEs.  */
 
diff --git a/src/filelock.c b/src/filelock.c
index 1b32b93110..57e3990041 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -253,14 +253,7 @@ get_boot_time_1 (const char *filename, bool newest)
   struct utmp ut, *utp;
 
   if (filename)
-    {
-      /* On some versions of IRIX, opening a nonexistent file name
-	 is likely to crash in the utmp routines.  */
-      if (faccessat (AT_FDCWD, filename, R_OK, AT_EACCESS) != 0)
-	return;
-
-      utmpname (filename);
-    }
+    utmpname (filename);
 
   setutent ();
 
diff --git a/src/process.c b/src/process.c
index 4359f681b4..69f5e1ddca 100644
--- a/src/process.c
+++ b/src/process.c
@@ -6464,7 +6464,7 @@ process_send_signal (Lisp_Object process, int signo, Lisp_Object current_group,
 	  break;
 
   	case SIGTSTP:
-#if defined (VSWTCH) && !defined (PREFER_VSUSP)
+#ifdef VSWTCH
 	  sig_char = &t.c_cc[VSWTCH];
 #else
 	  sig_char = &t.c_cc[VSUSP];
diff --git a/src/unexelf.c b/src/unexelf.c
index e90199472e..6343207bd1 100644
--- a/src/unexelf.c
+++ b/src/unexelf.c
@@ -461,29 +461,6 @@ unexec (const char *new_name, const char *old_name)
 	  || !strcmp (old_section_names + new_shdr->sh_name, ".sdata")
 	  || !strcmp (old_section_names + new_shdr->sh_name, ".lit4")
 	  || !strcmp (old_section_names + new_shdr->sh_name, ".lit8")
-	  /* The conditional bit below was in Oliva's original code
-	     (1999-08-25) and seems to have been dropped by mistake
-	     subsequently.  It prevents a crash at startup under X in
-	     `IRIX64 6.5 6.5.17m', whether compiled on that release or
-	     an earlier one.  It causes no trouble on the other ELF
-	     platforms I could test (Irix 6.5.15m, Solaris 8, Debian
-	     Potato x86, Debian Woody SPARC); however, it's reported
-	     to cause crashes under some version of GNU/Linux.  It's
-	     not yet clear what's changed in that Irix version to
-	     cause the problem, or why the fix sometimes fails under
-	     GNU/Linux.  There's probably no good reason to have
-	     something Irix-specific here, but this will have to do
-	     for now.  IRIX6_5 is the most specific macro we have to
-	     test.  -- fx 2002-10-01
-
-	     The issue _looks_ as though it's gone away on 6.5.18m,
-	     but maybe it's still lurking, to be triggered by some
-	     change in the binary.  It appears to concern the dynamic
-	     loader, but I never got anywhere with an SGI support call
-	     seeking clues.  -- fx 2002-11-29.  */
-#ifdef IRIX6_5
-	  || !strcmp (old_section_names + new_shdr->sh_name, ".got")
-#endif
 	  || !strcmp (old_section_names + new_shdr->sh_name, ".sdata1")
 	  || !strcmp (old_section_names + new_shdr->sh_name, ".data1"))
 	src = (caddr_t) old_shdr->sh_addr;
@@ -665,9 +642,6 @@ unexec (const char *new_name, const char *old_name)
 	      || !strcmp (old_section_names + shdr->sh_name, ".sdata")
 	      || !strcmp (old_section_names + shdr->sh_name, ".lit4")
 	      || !strcmp (old_section_names + shdr->sh_name, ".lit8")
-#ifdef IRIX6_5			/* see above */
-	      || !strcmp (old_section_names + shdr->sh_name, ".got")
-#endif
 	      || !strcmp (old_section_names + shdr->sh_name, ".sdata1")
 	      || !strcmp (old_section_names + shdr->sh_name, ".data1"))
 	    {