Fix the MS-Windows build broken by SAFE_ALLOCA changes.

[gnu-emacs] / configure.ac

diff --git a/configure.ac b/configure.ac
index aa17bf55194c80175c7f49e7e511420cbd86e767..6bfa8cc4ad291d9fafabe815a9f8ee65baa3ef52 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -93,32 +93,35 @@ AC_DEFUN([AC_PROG_MAKE_SET],
    AC_SUBST([SET_MAKE])])
 
 dnl Check for GNU Make and possibly set MAKE before running AM_INIT_AUTOMAKE.
    AC_SUBST([SET_MAKE])])
 
 dnl Check for GNU Make and possibly set MAKE before running AM_INIT_AUTOMAKE.

+[emacs_check_gnu_make ()
+{
+  emacs_makeout=`($1 --version) 2>/dev/null` &&
+  case $emacs_makeout in
+    'GNU Make '3.8[1-9]* | 'GNU Make '3.9[0-9]* | \
+    'GNU Make '3.[1-9][0-9][0-9]* | 'GNU Make '[4-9]* | 'GNU Make '[1-9][0-9]* )
+       ac_path_MAKE_found=:;;
+  esac
+}]

 AC_CACHE_CHECK([for GNU Make], [ac_cv_path_MAKE],
   [ac_path_MAKE_found=false
    if test -n "$MAKE"; then
 AC_CACHE_CHECK([for GNU Make], [ac_cv_path_MAKE],
   [ac_path_MAKE_found=false
    if test -n "$MAKE"; then

-     emacs_makeout=`($MAKE --version) 2>/dev/null` &&
-     case $emacs_makeout in
-       'GNU Make '[[4-9]]* | 'GNU Make '3.8[[1-9]]* | 'GNU Make '3.9*)
-        ac_path_MAKE_found=:;;
-     esac
+     emacs_check_gnu_make "$MAKE"

      ac_cv_path_MAKE=$MAKE
    else
      emacs_tried_make=false
      emacs_tried_gmake=false
      emacs_tried_gnumake=false
      AC_PATH_PROGS_FEATURE_CHECK([MAKE], [make gmake gnumake],
      ac_cv_path_MAKE=$MAKE
    else
      emacs_tried_make=false
      emacs_tried_gmake=false
      emacs_tried_gnumake=false
      AC_PATH_PROGS_FEATURE_CHECK([MAKE], [make gmake gnumake],

-       [[emacs_makeout=`($ac_path_MAKE --version) 2>/dev/null` &&
-        case $emacs_makeout in
-          'GNU Make '[4-9]* | 'GNU Make '3.8[1-9]* | 'GNU Make '3.9*)
-             # Use the fully-qualified program name only if the basename
-             # would not resolve to it.
-             if eval \$emacs_tried_$ac_prog; then
-               ac_cv_path_MAKE=$ac_path_MAKE
-             else
-               ac_cv_path_MAKE=$ac_prog
-             fi
-             ac_path_MAKE_found=:;;
-        esac
+       [[emacs_check_gnu_make "$ac_path_MAKE"
+        if $ac_path_MAKE_found; then
+          # Use the fully-qualified program name only if the basename
+          # would not resolve to it.
+          if eval \$emacs_tried_$ac_prog; then
+            ac_cv_path_MAKE=$ac_path_MAKE
+          else
+            ac_cv_path_MAKE=$ac_prog
+          fi
+        fi

         eval emacs_tried_$ac_prog=:]])
    fi])
 $ac_path_MAKE_found || {
         eval emacs_tried_$ac_prog=:]])
    fi])
 $ac_path_MAKE_found || {


@@ -127,6 +130,7 @@ If you have it installed under another name, configure with 'MAKE=...'.
 For example, run '$0 MAKE=gnu-make'.]])
 }
 MAKE=$ac_cv_path_MAKE
 For example, run '$0 MAKE=gnu-make'.]])
 }
 MAKE=$ac_cv_path_MAKE

+export MAKE

 
 dnl Fairly arbitrary, older versions might work too.
 AM_INIT_AUTOMAKE(1.11)
 
 dnl Fairly arbitrary, older versions might work too.
 AM_INIT_AUTOMAKE(1.11)


@@ -136,7 +140,7 @@ AC_CANONICAL_HOST
 canonical=$host
 configuration=${host_alias-${build_alias-$host}}
 
 canonical=$host
 configuration=${host_alias-${build_alias-$host}}
 

-dnl We get MINGW64 with MSYS2.
+dnl We get MINGW64 with MSYS2, MINGW32 with MSYS.

 case $canonical in
  *-mingw*)
   . $srcdir/nt/mingw-cfg.site
 case $canonical in
  *-mingw*)
   . $srcdir/nt/mingw-cfg.site


@@ -647,7 +651,7 @@ case "${canonical}" in
   i[3456]86-*-* )
     case "${canonical}" in
       *-darwin* )               opsys=darwin ;;
   i[3456]86-*-* )
     case "${canonical}" in
       *-darwin* )               opsys=darwin ;;

-      *-mingw32 )
+      *-mingw* )

                opsys=mingw32
                # MinGW overrides and adds some system headers in nt/inc.
                GCC_TEST_OPTIONS="-I $srcdir/nt/inc"
                opsys=mingw32
                # MinGW overrides and adds some system headers in nt/inc.
                GCC_TEST_OPTIONS="-I $srcdir/nt/inc"


@@ -662,7 +666,7 @@ case "${canonical}" in
   # MinGW64
   x86_64-*-* )
     case "${canonical}" in
   # MinGW64
   x86_64-*-* )
     case "${canonical}" in

-      *-mingw32 )
+      *-mingw* )

                opsys=mingw32
                # MinGW overrides and adds some system headers in nt/inc.
                GCC_TEST_OPTIONS="-I $srcdir/nt/inc"
                opsys=mingw32
                # MinGW overrides and adds some system headers in nt/inc.
                GCC_TEST_OPTIONS="-I $srcdir/nt/inc"


@@ -840,10 +844,8 @@ else
 
   nw="$nw -Wsystem-headers"         # Don't let system headers trigger warnings
   nw="$nw -Woverlength-strings"     # Not a problem these days
 
   nw="$nw -Wsystem-headers"         # Don't let system headers trigger warnings
   nw="$nw -Woverlength-strings"     # Not a problem these days

-  nw="$nw -Wlogical-op"             # any use of fwrite provokes this

   nw="$nw -Wformat-nonliteral"      # we do this a lot
   nw="$nw -Wformat-nonliteral"      # we do this a lot

-  nw="$nw -Wvla"                    # warnings in gettext.h
-  nw="$nw -Wnested-externs"         # use of XARGMATCH/verify_function__
+  nw="$nw -Wvla"                    # Emacs uses <vla.h>.

   nw="$nw -Wswitch-default"         # Too many warnings for now
   nw="$nw -Winline"                 # OK to ignore 'inline'
   nw="$nw -Wjump-misses-init"       # We sometimes safely jump over init.
   nw="$nw -Wswitch-default"         # Too many warnings for now
   nw="$nw -Winline"                 # OK to ignore 'inline'
   nw="$nw -Wjump-misses-init"       # We sometimes safely jump over init.


@@ -860,7 +862,8 @@ else
   # Emacs's use of alloca inhibits protecting the stack.
   nw="$nw -Wstack-protector"
 
   # Emacs's use of alloca inhibits protecting the stack.
   nw="$nw -Wstack-protector"
 

-  # The following line should be removable at some point.
+  # Emacs's use of partly-pure functions such as CHECK_TYPE make this
+  # option problematic.

   nw="$nw -Wsuggest-attribute=pure"
 
   # This part is merely for shortening the command line,
   nw="$nw -Wsuggest-attribute=pure"
 
   # This part is merely for shortening the command line,


@@ -879,6 +882,7 @@ else
   for w in $ws; do
     gl_WARN_ADD([$w])
   done
   for w in $ws; do
     gl_WARN_ADD([$w])
   done

+  gl_WARN_ADD([-Wredundant-decls])     # Prefer this, as we don't use Bison.

   gl_WARN_ADD([-Wno-missing-field-initializers]) # We need this one
   gl_WARN_ADD([-Wno-sign-compare])     # Too many warnings for now
   gl_WARN_ADD([-Wno-type-limits])      # Too many warnings for now
   gl_WARN_ADD([-Wno-missing-field-initializers]) # We need this one
   gl_WARN_ADD([-Wno-sign-compare])     # Too many warnings for now
   gl_WARN_ADD([-Wno-type-limits])      # Too many warnings for now


@@ -886,10 +890,6 @@ else
   gl_WARN_ADD([-Wno-unused-parameter]) # Too many warnings for now
   gl_WARN_ADD([-Wno-format-nonliteral])
 
   gl_WARN_ADD([-Wno-unused-parameter]) # Too many warnings for now
   gl_WARN_ADD([-Wno-format-nonliteral])
 

-  # In spite of excluding -Wlogical-op above, it is enabled, as of
-  # gcc 4.5.0 20090517.
-  gl_WARN_ADD([-Wno-logical-op])
-

   # More things that clang is unduly picky about.
   if test $emacs_cv_clang = yes; then
     gl_WARN_ADD([-Wno-format-extra-args])
   # More things that clang is unduly picky about.
   if test $emacs_cv_clang = yes; then
     gl_WARN_ADD([-Wno-format-extra-args])


@@ -927,8 +927,11 @@ edit_cflags="
 AC_ARG_ENABLE(link-time-optimization,
 [AS_HELP_STRING([--enable-link-time-optimization],
                 [build emacs with link-time optimization.
 AC_ARG_ENABLE(link-time-optimization,
 [AS_HELP_STRING([--enable-link-time-optimization],
                 [build emacs with link-time optimization.

-                This is supported for gcc since 4.5.0 and clang.
-                Note that clang support is experimental - see INSTALL])],
+                This requires GCC 4.5.0 or later, or clang.
+                (Note that clang support is experimental - see INSTALL.)
+                It also makes Emacs harder to debug, and when we tried it
+                with GCC 4.9.0 x86-64 it made Emacs slower, so it's not
+                recommended for typical use.])],

 if test "${enableval}" != "no"; then
    ac_lto_supported=no
    if test $emacs_cv_clang = yes; then
 if test "${enableval}" != "no"; then
    ac_lto_supported=no
    if test $emacs_cv_clang = yes; then


@@ -966,10 +969,28 @@ if test "${enableval}" != "no"; then
         # command, so plugin name is appended to ARFLAGS.
         ARFLAGS="cru --plugin $GOLD_PLUGIN"
         RANLIB="$RANLIB --plugin $GOLD_PLUGIN"
         # command, so plugin name is appended to ARFLAGS.
         ARFLAGS="cru --plugin $GOLD_PLUGIN"
         RANLIB="$RANLIB --plugin $GOLD_PLUGIN"

+      else
+        dnl The following is needed for GCC 4.9.0.  The GCC 4.9.0 release notes
+        dnl suggest that instead of -ffat-lto-objects we should use gcc-ar and
+        dnl gcc-ranlib in place of ar and ranlib, but gcc-ar makes /usr/bin/ar
+        dnl dump core on Fedora 20, so play it safe for now.
+        gl_COMPILER_OPTION_IF([-ffat-lto-objects],
+          [CFLAGS="$CFLAGS -ffat-lto-objects"])

       fi
    fi
 fi)
 
       fi
    fi
 fi)
 

+dnl Port to Automake 1.11.
+dnl This section can be removed once we assume Automake 1.14 or later.
+: ${AM_DEFAULT_VERBOSITY=1}
+: ${AM_V=$AM_DEFAULT_VERBOSITY}
+: ${AM_DEFAULT_V=$AM_DEFAULT_VERBOSITY}
+AC_SUBST([AM_V])
+AM_SUBST_NOTMAKE([AM_V])
+AC_SUBST([AM_DEFAULT_V])
+AM_SUBST_NOTMAKE([AM_DEFAULT_V])
+AC_SUBST([AM_DEFAULT_VERBOSITY])
+

 dnl Some other nice autoconf tests.
 dnl These are commented out, since gl_EARLY and/or Autoconf already does them.
 dnl AC_PROG_INSTALL
 dnl Some other nice autoconf tests.
 dnl These are commented out, since gl_EARLY and/or Autoconf already does them.
 dnl AC_PROG_INSTALL


@@ -1077,15 +1098,16 @@ if test $opsys = gnu-linux; then
 fi
 
 ## Need makeinfo >= 4.7 (?) to build the manuals.
 fi
 
 ## Need makeinfo >= 4.7 (?) to build the manuals.

-AC_PATH_PROG(MAKEINFO, makeinfo, no)
-dnl By this stage, configure has already checked for egrep and set EGREP,
-dnl or exited with an error if no egrep was found.

 if test "$MAKEINFO" != "no"; then
 if test "$MAKEINFO" != "no"; then

-  case `
-    $MAKEINFO --version 2> /dev/null |
-    $EGREP 'texinfo[[^0-9]]*([[1-4]][[0-9]]+|[[5-9]]|4\.[[7-9]]|4\.[[1-6]][[0-9]]+)'
-  ` in
-    '') MAKEINFO=no;;
+  if test "$MAKEINFO" = "${am_missing_run}makeinfo"; then
+    MAKEINFO=makeinfo
+  fi
+  case `($MAKEINFO --version) 2>/dev/null` in
+    'makeinfo (GNU texinfo) '4.[[7-9]]* | \
+    'makeinfo (GNU texinfo) '4.[[1-9][0-9]]* | \
+    'makeinfo (GNU texinfo) '[[5-9]]* | \
+    'makeinfo (GNU texinfo) '[[1-9][0-9]]* ) ;;
+    *) MAKEINFO=no;;

   esac
 fi
 
   esac
 fi
 


@@ -1309,7 +1331,7 @@ test "$opsys" = "aix4.2" && test "x$GCC" != "xyes" && \
   C_SWITCH_SYSTEM="-ma -qmaxmem=4000"
 if test "$opsys" = "mingw32"; then
   case "$canonical" in
   C_SWITCH_SYSTEM="-ma -qmaxmem=4000"
 if test "$opsys" = "mingw32"; then
   case "$canonical" in

-    x86_64-*-mingw32) C_SWITCH_SYSTEM="-mtune=generic" ;;
+    x86_64-*-mingw*) C_SWITCH_SYSTEM="-mtune=generic" ;;

     *) C_SWITCH_SYSTEM="-mtune=pentium4" ;;
   esac
 fi
     *) C_SWITCH_SYSTEM="-mtune=pentium4" ;;
   esac
 fi


@@ -1496,6 +1518,7 @@ fi
 dnl checks for header files
 AC_CHECK_HEADERS_ONCE(
   sys/systeminfo.h
 dnl checks for header files
 AC_CHECK_HEADERS_ONCE(
   sys/systeminfo.h

+  sys/sysinfo.h

   coff.h pty.h
   sys/resource.h
   sys/utsname.h pwd.h utmp.h util.h)
   coff.h pty.h
   sys/resource.h
   sys/utsname.h pwd.h utmp.h util.h)


@@ -1511,6 +1534,26 @@ if test $emacs_cv_personality_linux32 = yes; then
             [Define to 1 if personality LINUX32 can be set.])
 fi
 
             [Define to 1 if personality LINUX32 can be set.])
 fi
 

+# Note that Solaris has sys/sysinfo.h which defines struct
+# sysinfo as well.  To make sure that we're using GNU/Linux
+# sysinfo, we explicitly set one of its fields.
+if test "$ac_cv_header_sys_sysinfo_h" = yes; then
+  AC_MSG_CHECKING([if Linux sysinfo may be used])
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/sysinfo.h>]],
+                                     [[struct sysinfo si;
+                                       si.totalram = 0;
+                                       sysinfo (&si)]])],
+    emacs_cv_linux_sysinfo=yes, emacs_cv_linux_sysinfo=no)
+  AC_MSG_RESULT($emacs_cv_linux_sysinfo)
+  if test $emacs_cv_linux_sysinfo = yes; then
+    AC_DEFINE([HAVE_LINUX_SYSINFO], 1, [Define to 1 if you have Linux sysinfo function.])
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/sysinfo.h>]],
+                                       [[struct sysinfo si; return si.mem_unit]])],
+      AC_DEFINE(LINUX_SYSINFO_UNIT, 1,
+                [Define to 1 if Linux sysinfo sizes are in multiples of mem_unit bytes.]))
+  fi
+fi
+

 dnl On Solaris 8 there's a compilation warning for term.h because
 dnl it doesn't define `bool'.
 AC_CHECK_HEADERS(term.h, , , -)
 dnl On Solaris 8 there's a compilation warning for term.h because
 dnl it doesn't define `bool'.
 AC_CHECK_HEADERS(term.h, , , -)


@@ -1576,11 +1619,14 @@ if test "$GCC" = yes && test "$ac_enable_autodepend" = yes; then
       deps_frag=autodeps.mk
    fi
 fi
       deps_frag=autodeps.mk
    fi
 fi

+lwlib_deps_frag=$srcdir/lwlib/$deps_frag
+oldxmenu_deps_frag=$srcdir/oldXMenu/$deps_frag

 deps_frag=$srcdir/src/$deps_frag
 AC_SUBST(MKDEPDIR)
 AC_SUBST(DEPFLAGS)
 AC_SUBST_FILE(deps_frag)
 deps_frag=$srcdir/src/$deps_frag
 AC_SUBST(MKDEPDIR)
 AC_SUBST(DEPFLAGS)
 AC_SUBST_FILE(deps_frag)

-
+AC_SUBST_FILE(lwlib_deps_frag)
+AC_SUBST_FILE(oldxmenu_deps_frag)

 
 lisp_frag=$srcdir/src/lisp.mk
 AC_SUBST_FILE(lisp_frag)
 
 lisp_frag=$srcdir/src/lisp.mk
 AC_SUBST_FILE(lisp_frag)


@@ -1995,9 +2041,13 @@ AC_CACHE_CHECK(
 doug_lea_malloc=$emacs_cv_var_doug_lea_malloc
 
 system_malloc=$emacs_cv_sanitize_address
 doug_lea_malloc=$emacs_cv_var_doug_lea_malloc
 
 system_malloc=$emacs_cv_sanitize_address

+
+hybrid_malloc=
+

 case "$opsys" in
   ## darwin ld insists on the use of malloc routines in the System framework.
   darwin|mingw32|sol2-10) system_malloc=yes ;;
 case "$opsys" in
   ## darwin ld insists on the use of malloc routines in the System framework.
   darwin|mingw32|sol2-10) system_malloc=yes ;;

+  cygwin) hybrid_malloc=yes;;

 esac
 
 GMALLOC_OBJ=
 esac
 
 GMALLOC_OBJ=


@@ -2009,6 +2059,13 @@ if test "${system_malloc}" = "yes"; then
   GNU_MALLOC_reason="
     (The GNU allocators don't work with this system configuration.)"
   VMLIMIT_OBJ=
   GNU_MALLOC_reason="
     (The GNU allocators don't work with this system configuration.)"
   VMLIMIT_OBJ=

+elif test "$hybrid_malloc" = yes; then
+  AC_DEFINE(HYBRID_MALLOC, 1,
+    [Define to use gmalloc before dumping and the system malloc after.])
+  GNU_MALLOC=
+  GNU_MALLOC_reason="only before dumping"
+  GMALLOC_OBJ=gmalloc.o
+  VMLIMIT_OBJ=

 else
   test "$doug_lea_malloc" != "yes" && GMALLOC_OBJ=gmalloc.o
   VMLIMIT_OBJ=vm-limit.o
 else
   test "$doug_lea_malloc" != "yes" && GMALLOC_OBJ=gmalloc.o
   VMLIMIT_OBJ=vm-limit.o


@@ -2088,11 +2145,15 @@ if test "$ac_cv_header_pthread_h"; then
      # Some systems optimize for single-threaded programs by default, and
      # need special flags to disable these optimizations. For example, the
      # definition of 'errno' in <errno.h>.
      # Some systems optimize for single-threaded programs by default, and
      # need special flags to disable these optimizations. For example, the
      # definition of 'errno' in <errno.h>.

-     if test "$opsys" = aix4-2; then
-       AC_DEFINE([_THREAD_SAFE], [1],
-         [Define to 1 if your system requires this in multithreaded code.])
-     fi])
-  if test "X$LIBS" != "X$OLD_LIBS"; then
+     case $opsys in
+       sol*)
+         AC_DEFINE([_REENTRANT], 1,
+       [Define to 1 if your system requires this in multithreaded code.]);;
+       aix4-2)
+         AC_DEFINE([_THREAD_SAFE], 1,
+       [Define to 1 if your system requires this in multithreaded code.]);;
+     esac])
+ if test "X$LIBS" != "X$OLD_LIBS"; then

     eval LIB_PTHREAD=\$ac_cv_search_$emacs_pthread_function
   fi
   LIBS=$OLD_LIBS
     eval LIB_PTHREAD=\$ac_cv_search_$emacs_pthread_function
   fi
   LIBS=$OLD_LIBS


@@ -2954,6 +3015,9 @@ AC_SUBST(M17N_FLT_LIBS)
 
 ### Use -lXpm if available, unless `--with-xpm=no'.
 ### mingw32 doesn't use -lXpm, since it loads the library dynamically.
 
 ### Use -lXpm if available, unless `--with-xpm=no'.
 ### mingw32 doesn't use -lXpm, since it loads the library dynamically.

+### In the Cygwin-w32 build, we need to use /usr/include/noX/X11/xpm.h
+### rather than /usr/include/X11/xpm.h, so we set CPPFLAGS (and
+### LDFLAGS) accordingly.

 HAVE_XPM=no
 LIBXPM=
 if test "${HAVE_W32}" = "yes" && test "${opsys}" = "cygwin"; then
 HAVE_XPM=no
 LIBXPM=
 if test "${HAVE_W32}" = "yes" && test "${opsys}" = "cygwin"; then


@@ -3510,10 +3574,10 @@ AC_SUBST(BLESSMAIL_TARGET)
 
 OLD_LIBS=$LIBS
 LIBS="$LIB_PTHREAD $LIB_MATH $LIBS"
 
 OLD_LIBS=$LIBS
 LIBS="$LIB_PTHREAD $LIB_MATH $LIBS"

-AC_CHECK_FUNCS(accept4 gethostname \
+AC_CHECK_FUNCS(accept4 fchdir gethostname \

 getrusage get_current_dir_name \
 lrand48 random rint \
 getrusage get_current_dir_name \
 lrand48 random rint \

-select getpagesize setlocale \
+select getpagesize setlocale newlocale \

 getrlimit setrlimit shutdown getaddrinfo \
 pthread_sigmask strsignal setitimer \
 sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \
 getrlimit setrlimit shutdown getaddrinfo \
 pthread_sigmask strsignal setitimer \
 sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \


@@ -3523,9 +3587,11 @@ cfmakeraw cfsetspeed copysign __executable_start log2)
 LIBS=$OLD_LIBS
 
 dnl No need to check for aligned_alloc and posix_memalign if using
 LIBS=$OLD_LIBS
 
 dnl No need to check for aligned_alloc and posix_memalign if using

-dnl gmalloc.o, as it supplies them.  Don't use these functions on
-dnl Darwin as they are incompatible with unexmacosx.c.
-if test -z "$GMALLOC_OBJ" && test "$opsys" != darwin; then
+dnl gmalloc.o, as it supplies them, unless we're using hybrid_malloc.
+dnl Don't use these functions on Darwin as they are incompatible with
+dnl unexmacosx.c.
+if (test -z "$GMALLOC_OBJ" || test "$hybrid_malloc" = yes) \
+  && test "$opsys" != darwin; then

   AC_CHECK_FUNCS([aligned_alloc posix_memalign], [break])
 fi
 
   AC_CHECK_FUNCS([aligned_alloc posix_memalign], [break])
 fi
 


@@ -3673,6 +3739,36 @@ fi
 AC_SUBST(LIBS_TERMCAP)
 AC_SUBST(TERMCAP_OBJ)
 
 AC_SUBST(LIBS_TERMCAP)
 AC_SUBST(TERMCAP_OBJ)
 

+# GNU/Linux-specific timer functions.
+AC_CACHE_CHECK([for timerfd interface], [emacs_cv_have_timerfd],
+  [AC_COMPILE_IFELSE(
+     [AC_LANG_PROGRAM([[#include <sys/timerfd.h>
+                     ]],
+                     [[timerfd_create (CLOCK_REALTIME,
+                                       TFD_CLOEXEC | TFD_NONBLOCK);
+                       timerfd_settime (0, TFD_TIMER_ABSTIME, 0, 0);]])],
+     [emacs_cv_have_timerfd=yes],
+     [emacs_cv_have_timerfd=no])])
+if test "$emacs_cv_have_timerfd" = yes; then
+  AC_DEFINE([HAVE_TIMERFD], 1,
+    [Define to 1 if timerfd functions are supported as in GNU/Linux.])
+fi
+
+# Alternate stack for signal handlers.
+AC_CACHE_CHECK([whether signals can be handled on alternate stack],
+              [emacs_cv_alternate_stack],
+  [AC_COMPILE_IFELSE(
+     [AC_LANG_PROGRAM([[#include <signal.h>
+                     ]],
+                     [[stack_t ss;
+                       struct sigaction sa;
+                       ss.ss_sp = malloc (SIGSTKSZ);
+                       ss.ss_size = SIGSTKSZ;
+                       sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
+                       sigaltstack (&ss, 0);
+                       sigaction (SIGSEGV, &sa, 0);]])],
+     [emacs_cv_alternate_stack=yes],
+     [emacs_cv_alternate_stack=no])])

 
 # Do we have res_init, for detecting changes in /etc/resolv.conf?
 # On Darwin, res_init appears not to be useful: see bug#562 and
 
 # Do we have res_init, for detecting changes in /etc/resolv.conf?
 # On Darwin, res_init appears not to be useful: see bug#562 and


@@ -3916,15 +4012,6 @@ fi
 
 AC_TYPE_MBSTATE_T
 
 
 AC_TYPE_MBSTATE_T
 

-AC_CACHE_CHECK([for C restricted array declarations], emacs_cv_c_restrict_arr,
-  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[void fred (int x[__restrict]);]], [[]])],
-                  emacs_cv_c_restrict_arr=yes, emacs_cv_c_restrict_arr=no)])
-if test "$emacs_cv_c_restrict_arr" = yes; then
-  AC_DEFINE(__restrict_arr, __restrict,
-    [Define to compiler's equivalent of C99 restrict keyword in array
-     declarations.  Define as empty for no equivalent.])
-fi
-

 dnl Fixme: AC_SYS_POSIX_TERMIOS should probably be used, but it's not clear
 dnl how the tty code is related to POSIX and/or other versions of termios.
 dnl The following looks like a useful start.
 dnl Fixme: AC_SYS_POSIX_TERMIOS should probably be used, but it's not clear
 dnl how the tty code is related to POSIX and/or other versions of termios.
 dnl The following looks like a useful start.


@@ -4393,22 +4480,31 @@ AC_CACHE_CHECK([for _setjmp], [emacs_cv_func__setjmp],
      [emacs_cv_func__setjmp=no])])
 if test $emacs_cv_func__setjmp = yes; then
   AC_DEFINE([HAVE__SETJMP], 1, [Define to 1 if _setjmp and _longjmp work.])
      [emacs_cv_func__setjmp=no])])
 if test $emacs_cv_func__setjmp = yes; then
   AC_DEFINE([HAVE__SETJMP], 1, [Define to 1 if _setjmp and _longjmp work.])

-else
-  AC_CACHE_CHECK([for sigsetjmp], [emacs_cv_func_sigsetjmp],
-    [AC_LINK_IFELSE(
-       [AC_LANG_PROGRAM(
-        [[#include <setjmp.h>
-        ]],
-        [[sigjmp_buf j;
-          if (! sigsetjmp (j, 1))
-            siglongjmp (j, 1);]])],
-       [emacs_cv_func_sigsetjmp=yes],
-       [emacs_cv_func_sigsetjmp=no])])
-  if test $emacs_cv_func_sigsetjmp = yes; then
-    AC_DEFINE([HAVE_SIGSETJMP], 1,
-      [Define to 1 if sigsetjmp and siglongjmp work.
-       The value of this symbol is irrelevant if HAVE__SETJMP is defined.])
-  fi
+fi
+
+# We need to preserve signal mask to handle C stack overflows.
+AC_CACHE_CHECK([for sigsetjmp], [emacs_cv_func_sigsetjmp],
+  [AC_LINK_IFELSE(
+     [AC_LANG_PROGRAM(
+       [[#include <setjmp.h>
+       ]],
+       [[sigjmp_buf j;
+         if (! sigsetjmp (j, 1))
+          siglongjmp (j, 1);]])],
+     [emacs_cv_func_sigsetjmp=yes],
+     [emacs_cv_func_sigsetjmp=no])])
+if test $emacs_cv_func_sigsetjmp = yes; then
+  AC_DEFINE([HAVE_SIGSETJMP], 1,
+    [Define to 1 if sigsetjmp and siglongjmp work.])
+fi
+
+# We need all of these features to handle C stack overflows.
+if test "$ac_cv_header_sys_resource_h" = "yes" -a \
+       "$ac_cv_func_getrlimit" = "yes" -a \
+       "$emacs_cv_func_sigsetjmp" = "yes" -a \
+       "$emacs_cv_alternate_stack" = yes; then
+  AC_DEFINE([HAVE_STACK_OVERFLOW_HANDLING], 1,
+    [Define to 1 if C stack overflow can be handled in some cases.])

 fi
 
 case $opsys in
 fi
 
 case $opsys in


@@ -4539,20 +4635,7 @@ if test $emacs_cv_usable_FIONREAD = yes; then
   fi
 fi
 
   fi
 fi
 

-

 case $opsys in
 case $opsys in

-  dnl Emacs supplies its own malloc, but glib calls posix_memalign,
-  dnl and on Cygwin prior to version 1.7.24 that becomes the
-  dnl Cygwin-supplied posix_memalign.  As malloc is not the Cygwin
-  dnl malloc, the Cygwin posix_memalign always returns ENOSYS.  A
-  dnl workaround is to set G_SLICE=always-malloc.  This is no longer
-  dnl needed starting with cygwin-1.7.24, and it is no longer
-  dnl effective starting with glib-2.36. */
-  cygwin)
-    AC_DEFINE(G_SLICE_ALWAYS_MALLOC, 1, [Define to set the
-      G_SLICE environment variable to "always-malloc" at startup.])
-    ;;
-

   hpux11)
     dnl It works to open the pty's tty in the parent (Emacs), then
     dnl close and reopen it in the child.
   hpux11)
     dnl It works to open the pty's tty in the parent (Emacs), then
     dnl close and reopen it in the child.


@@ -5113,7 +5196,7 @@ if test "${opsys}" = "mingw32"; then
   ${MAKE-make} MAKEFILE_NAME=do-not-make-Makefile epaths-force-w32
 else
   ${MAKE-make} MAKEFILE_NAME=do-not-make-Makefile epaths-force
   ${MAKE-make} MAKEFILE_NAME=do-not-make-Makefile epaths-force-w32
 else
   ${MAKE-make} MAKEFILE_NAME=do-not-make-Makefile epaths-force

-fi
+fi || AC_MSG_ERROR(['src/epaths.h' could not be made.])

 ], [GCC="$GCC" CPPFLAGS="$CPPFLAGS" opsys="$opsys"])
 
 dnl NB we have to cheat and use the ac_... version because abs_top_srcdir
 ], [GCC="$GCC" CPPFLAGS="$CPPFLAGS" opsys="$opsys"])
 
 dnl NB we have to cheat and use the ac_... version because abs_top_srcdir