Merge from gnulib.

* src/conf_post.h (__has_builtin, assume): Remove; gnulib now does these.
* src/lisp.h: Include <verify.h>, for 'assume'.

This also incorpoprates:
2013-10-02 verify: new macro 'assume'
2013-09-26 dup2, dup3: work around another cygwin crasher
2013-09-26 getdtablesize: work around cygwin issue

13 files changed, 118 insertions, 33 deletions

diff --git a/ChangeLog b/ChangeLog
index f8a219d6a15..44e83d25737 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2013-10-03  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Merge from gnulib, incorporating:
+        2013-10-02 verify: new macro 'assume'
+        2013-09-26 dup2, dup3: work around another cygwin crasher
+        2013-09-26 getdtablesize: work around cygwin issue
+
 2013-09-25  Paul Eggert  <eggert@cs.ucla.edu>
 
         Merge from gnulib, incorporating:
diff --git a/lib/dup2.c b/lib/dup2.c
index 9219eb38238..f128e7a63cd 100644
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -96,7 +96,11 @@ rpl_dup2 (int fd, int desired_fd)
   /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF.
      On Cygwin 1.5.x, dup2 (1, 1) returns 0.
      On Cygwin 1.7.17, dup2 (1, -1) dumps core.
+     On Cygwin 1.7.25, dup2 (1, 256) can dump core.
      On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC.  */
+#  if HAVE_SETDTABLESIZE
+  setdtablesize (desired_fd + 1);
+#  endif
   if (desired_fd < 0)
     fd = desired_fd;
   if (fd == desired_fd)
diff --git a/lib/getdtablesize.c b/lib/getdtablesize.c
index 9947405af61..355c17e3b9e 100644
--- a/lib/getdtablesize.c
+++ b/lib/getdtablesize.c
@@ -22,11 +22,11 @@
 
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 
-#include <stdio.h>
+# include <stdio.h>
 
-#include "msvc-inval.h"
+# include "msvc-inval.h"
 
-#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
 static int
 _setmaxstdio_nothrow (int newmax)
 {
@@ -44,10 +44,11 @@ _setmaxstdio_nothrow (int newmax)
 
   return result;
 }
-# define _setmaxstdio _setmaxstdio_nothrow
-#endif
+#  define _setmaxstdio _setmaxstdio_nothrow
+# endif
 
-/* Cache for the previous getdtablesize () result.  */
+/* Cache for the previous getdtablesize () result.  Safe to cache because
+   Windows also lacks setrlimit.  */
 static int dtablesize;
 
 int
@@ -83,4 +84,24 @@ getdtablesize (void)
   return dtablesize;
 }
 
+#elif HAVE_GETDTABLESIZE
+
+# include <sys/resource.h>
+# undef getdtablesize
+
+int
+rpl_getdtablesize(void)
+{
+  /* To date, this replacement is only compiled for Cygwin 1.7.25,
+     which auto-increased the RLIMIT_NOFILE soft limit until it
+     hits the compile-time constant hard limit of 3200.  Although
+     that version of cygwin supported a child process inheriting
+     a smaller soft limit, the smaller limit is not enforced, so
+     we might as well just report the hard limit.  */
+  struct rlimit lim;
+  if (!getrlimit (RLIMIT_NOFILE, &lim) && lim.rlim_max != RLIM_INFINITY)
+    return lim.rlim_max;
+  return getdtablesize ();
+}
+
 #endif
diff --git a/lib/gnulib.mk b/lib/gnulib.mk
index 32255181fb4..14d45e798e5 100644
--- a/lib/gnulib.mk
+++ b/lib/gnulib.mk
@@ -1707,6 +1707,7 @@ unistd.h: unistd.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
               -e 's|@''REPLACE_FTRUNCATE''@|$(REPLACE_FTRUNCATE)|g' \
               -e 's|@''REPLACE_GETCWD''@|$(REPLACE_GETCWD)|g' \
               -e 's|@''REPLACE_GETDOMAINNAME''@|$(REPLACE_GETDOMAINNAME)|g' \
+              -e 's|@''REPLACE_GETDTABLESIZE''@|$(REPLACE_GETDTABLESIZE)|g' \
               -e 's|@''REPLACE_GETLOGIN_R''@|$(REPLACE_GETLOGIN_R)|g' \
               -e 's|@''REPLACE_GETGROUPS''@|$(REPLACE_GETGROUPS)|g' \
               -e 's|@''REPLACE_GETPAGESIZE''@|$(REPLACE_GETPAGESIZE)|g' \
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 874c628a63b..0e510d679c6 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -654,10 +654,19 @@ _GL_WARN_ON_USE (getdomainname, "getdomainname is unportable - "
 #if @GNULIB_GETDTABLESIZE@
 /* Return the maximum number of file descriptors in the current process.
    In POSIX, this is same as sysconf (_SC_OPEN_MAX).  */
-# if !@HAVE_GETDTABLESIZE@
+# if @REPLACE_GETDTABLESIZE@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef getdtablesize
+#   define getdtablesize rpl_getdtablesize
+#  endif
+_GL_FUNCDECL_RPL (getdtablesize, int, (void));
+_GL_CXXALIAS_RPL (getdtablesize, int, (void));
+# else
+#  if !@HAVE_GETDTABLESIZE@
 _GL_FUNCDECL_SYS (getdtablesize, int, (void));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (getdtablesize, int, (void));
+# endif
 _GL_CXXALIASWARN (getdtablesize);
 #elif defined GNULIB_POSIXCHECK
 # undef getdtablesize
diff --git a/lib/verify.h b/lib/verify.h
index d42d0750ee1..bf40b028c92 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -250,6 +250,30 @@ template <int w>
 
 #define verify(R) _GL_VERIFY (R, "verify (" #R ")")
 
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
+/* Assume that R always holds.  This lets the compiler optimize
+   accordingly.  R should not have side-effects; it may or may not be
+   evaluated.  Behavior is undefined if R is false.  */
+
+#if (__has_builtin (__builtin_unreachable) \
+     || 4 < __GNUC__ + (5 <= __GNUC_MINOR__))
+# define assume(R) ((R) ? (void) 0 : __builtin_unreachable ())
+#elif 1200 <= _MSC_VER
+# define assume(R) __assume (R)
+#elif (defined lint \
+       && (__has_builtin (__builtin_trap) \
+           || 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__))))
+  /* Doing it this way helps various packages when configured with
+     --enable-gcc-warnings, which compiles with -Dlint.  It's nicer
+     when 'assume' silences warnings even with older GCCs.  */
+# define assume(R) ((R) ? (void) 0 : __builtin_trap ())
+#else
+# define assume(R) ((void) (0 && (R)))
+#endif
+
 /* @assert.h omit end@  */
 
 #endif
diff --git a/m4/dup2.m4 b/m4/dup2.m4
index 269cfdc1123..dc3070c0d9a 100644
--- a/m4/dup2.m4
+++ b/m4/dup2.m4
@@ -1,4 +1,4 @@
-#serial 19
+#serial 20
 dnl Copyright (C) 2002, 2005, 2007, 2009-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -39,9 +39,11 @@ AC_DEFUN([gl_FUNC_DUP2],
             /* Many gnulib modules require POSIX conformance of EBADF.  */
             if (dup2 (2, 1000000) == -1 && errno != EBADF)
               result |= 16;
-            /* Flush out a cygwin core dump.  */
+            /* Flush out some cygwin core dumps.  */
             if (dup2 (2, -1) != -1 || errno != EBADF)
               result |= 32;
+            dup2 (2, 255);
+            dup2 (2, 256);
             return result;
            ])
         ],
@@ -65,6 +67,7 @@ AC_DEFUN([gl_FUNC_DUP2],
       *yes) ;;
       *)
         REPLACE_DUP2=1
+        AC_CHECK_FUNCS([setdtablesize])
         ;;
     esac
   fi
diff --git a/m4/getdtablesize.m4 b/m4/getdtablesize.m4
index 8f04b3b8c2a..b3fa1af6a5a 100644
--- a/m4/getdtablesize.m4
+++ b/m4/getdtablesize.m4
@@ -1,4 +1,4 @@
-# getdtablesize.m4 serial 4
+# getdtablesize.m4 serial 5
 dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,8 +7,35 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_GETDTABLESIZE],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
   AC_CHECK_FUNCS_ONCE([getdtablesize])
-  if test $ac_cv_func_getdtablesize != yes; then
+  if test $ac_cv_func_getdtablesize = yes; then
+    # Cygwin 1.7.25 automatically increases the RLIMIT_NOFILE soft limit
+    # up to an unchangeable hard limit; all other platforms correctly
+    # require setrlimit before getdtablesize() can report a larger value.
+    AC_CACHE_CHECK([whether getdtablesize works],
+      [gl_cv_func_getdtablesize_works],
+      [AC_RUN_IFELSE([
+        AC_LANG_PROGRAM([[#include <unistd.h>]],
+          [int size = getdtablesize();
+           if (dup2 (0, getdtablesize()) != -1)
+             return 1;
+           if (size != getdtablesize())
+             return 2;
+          ])],
+        [gl_cv_func_getdtablesize_works=yes],
+        [gl_cv_func_getdtablesize_works=no],
+        [case "$host_os" in
+          cygwin*) # on cygwin 1.5.25, getdtablesize() automatically grows
+            gl_cv_func_getdtablesize_works="guessing no" ;;
+          *) gl_cv_func_getdtablesize_works="guessing yes" ;;
+         esac])
+      ])
+    case "$gl_cv_func_getdtablesize_works" in
+      *yes) ;;
+      *) REPLACE_GETDTABLESIZE=1 ;;
+    esac
+  else
     HAVE_GETDTABLESIZE=0
   fi
 ])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 7c5f22861b5..2e5a9cf97d1 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -433,7 +433,7 @@ AC_DEFUN([gl_INIT],
   {
     if ! $gl_gnulib_enabled_getdtablesize; then
       gl_FUNC_GETDTABLESIZE
-      if test $HAVE_GETDTABLESIZE = 0; then
+      if test $HAVE_GETDTABLESIZE = 0 || test $REPLACE_GETDTABLESIZE = 1; then
         AC_LIBOBJ([getdtablesize])
         gl_PREREQ_GETDTABLESIZE
       fi
diff --git a/m4/unistd_h.m4 b/m4/unistd_h.m4
index 32dcfa58204..4231578cf24 100644
--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -1,4 +1,4 @@
-# unistd_h.m4 serial 66
+# unistd_h.m4 serial 67
 dnl Copyright (C) 2006-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -160,6 +160,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   REPLACE_FTRUNCATE=0;    AC_SUBST([REPLACE_FTRUNCATE])
   REPLACE_GETCWD=0;       AC_SUBST([REPLACE_GETCWD])
   REPLACE_GETDOMAINNAME=0; AC_SUBST([REPLACE_GETDOMAINNAME])
+  REPLACE_GETDTABLESIZE=0; AC_SUBST([REPLACE_GETDTABLESIZE])
   REPLACE_GETLOGIN_R=0;   AC_SUBST([REPLACE_GETLOGIN_R])
   REPLACE_GETGROUPS=0;    AC_SUBST([REPLACE_GETGROUPS])
   REPLACE_GETPAGESIZE=0;  AC_SUBST([REPLACE_GETPAGESIZE])
diff --git a/src/ChangeLog b/src/ChangeLog
index 8a0d8863548..8713d493dca 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2013-10-03  Paul Eggert  <eggert@cs.ucla.edu>
 
+        Adjust to merge from gnulib.
+        * conf_post.h (__has_builtin, assume): Remove; gnulib now does these.
+        * lisp.h: Include <verify.h>, for 'assume'.
+
         * eval.c (clobbered_eassert): New macro.
         (internal_catch, internal_condition_case)
         (internal_condition_case_1, internal_condition_case_2)
diff --git a/src/conf_post.h b/src/conf_post.h
index 0786bdfeb33..786105864f2 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -248,23 +248,6 @@ extern void _DebPrint (const char *fmt, ...);
 # define FLEXIBLE_ARRAY_MEMBER 1
 #endif
 
-#ifndef __has_builtin
-# define __has_builtin(x) 0
-#endif
-
-/* Tell the compiler (and lint) that COND will always hold, and that
-   it should optimize (or check) accordingly.  */
-#if (__has_builtin (__builtin_unreachable) \
-     || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5) || __GNUC__ > 4)
-# define assume(cond) ((cond) ? (void) 0 : __builtin_unreachable ())
-#elif defined _MSC_VER
-# define assume(cond) __assume (cond)
-#elif defined lint
-# define assume(cond) ((cond) ? (void) 0 : abort ())
-#else
-# define assume(cond) ((void) (0 && (cond)))
-#endif
-
 /* Use this to suppress gcc's `...may be used before initialized' warnings. */
 #ifdef lint
 /* Use CODE only if lint checking is in effect.  */
diff --git a/src/lisp.h b/src/lisp.h
index 688c89c1eee..ee83e227db0 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -31,6 +31,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <limits.h>
 
 #include <intprops.h>
+#include <verify.h>
 
 INLINE_HEADER_BEGIN
 
@@ -1145,9 +1146,9 @@ struct Lisp_Vector
       /* ...but sometimes there is also a pointer internally used in
          vector allocation code.  Usually you don't want to touch this.  */
       struct Lisp_Vector *next;
-      
+
       /* We can't use FLEXIBLE_ARRAY_MEMBER here.  */
-      Lisp_Object contents[1]; 
+      Lisp_Object contents[1];
     } u;
   };