Merge branch 'release' into maintmaint

35 files changed, 120 insertions, 124 deletions

diff --git a/m4/amversion.in b/m4/amversion.in
index 4b845d888..99b14c283 100644
--- a/m4/amversion.in
+++ b/m4/amversion.in
@@ -1,6 +1,6 @@
 ##                                                          -*- Autoconf -*-
 ## @configure_input@
-# Copyright (C) 2002-2017 Free Software Foundation, Inc.
+# Copyright (C) 2002-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/amversion.m4 b/m4/amversion.m4
index 2a3ffec18..9e06a9ecf 100644
--- a/m4/amversion.m4
+++ b/m4/amversion.m4
@@ -1,6 +1,6 @@
 ##                                                          -*- Autoconf -*-
 ## Generated from amversion.in; do not edit by hand.
-# Copyright (C) 2002-2017 Free Software Foundation, Inc.
+# Copyright (C) 2002-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -12,10 +12,10 @@
 # generated from the m4 files accompanying Automake X.Y.
 # (This private macro should not be called outside this file.)
 AC_DEFUN([AM_AUTOMAKE_VERSION],
-[am__api_version='1.15'
+[am__api_version='1.16'
 dnl Some users find AM_AUTOMAKE_VERSION and mistake it for a way to
 dnl require some minimum version.  Point them to the right macro.
-m4_if([$1], [1.15.1a], [],
+m4_if([$1], [1.16], [],
       [AC_FATAL([Do not call $0, use AM_INIT_AUTOMAKE([$1]).])])dnl
 ])
 
@@ -31,7 +31,7 @@ m4_define([_AM_AUTOCONF_VERSION], [])
 # Call AM_AUTOMAKE_VERSION and AM_AUTOMAKE_VERSION so they can be traced.
 # This function is AC_REQUIREd by AM_INIT_AUTOMAKE.
 AC_DEFUN([AM_SET_CURRENT_AUTOMAKE_VERSION],
-[AM_AUTOMAKE_VERSION([1.15.1a])dnl
+[AM_AUTOMAKE_VERSION([1.16])dnl
 m4_ifndef([AC_AUTOCONF_VERSION],
   [m4_copy([m4_PACKAGE_VERSION], [AC_AUTOCONF_VERSION])])dnl
 _AM_AUTOCONF_VERSION(m4_defn([AC_AUTOCONF_VERSION]))])
diff --git a/m4/ar-lib.m4 b/m4/ar-lib.m4
index 4fe6fb34b..b4b7b8c7e 100644
--- a/m4/ar-lib.m4
+++ b/m4/ar-lib.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2011-2017 Free Software Foundation, Inc.
+# Copyright (C) 2011-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/as.m4 b/m4/as.m4
index 70ffc2e25..afe6013cc 100644
--- a/m4/as.m4
+++ b/m4/as.m4
@@ -1,6 +1,6 @@
 # Figure out how to run the assembler.                      -*- Autoconf -*-
 
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/auxdir.m4 b/m4/auxdir.m4
index ae4327de2..11bf3447e 100644
--- a/m4/auxdir.m4
+++ b/m4/auxdir.m4
@@ -1,6 +1,6 @@
 # AM_AUX_DIR_EXPAND                                         -*- Autoconf -*-
 
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/cond-if.m4 b/m4/cond-if.m4
index 2c62bd33b..e85646faa 100644
--- a/m4/cond-if.m4
+++ b/m4/cond-if.m4
@@ -1,6 +1,6 @@
 # AM_COND_IF                                            -*- Autoconf -*-
 
-# Copyright (C) 2008-2017 Free Software Foundation, Inc.
+# Copyright (C) 2008-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/cond.m4 b/m4/cond.m4
index 2a889d466..a0a006868 100644
--- a/m4/cond.m4
+++ b/m4/cond.m4
@@ -1,6 +1,6 @@
 # AM_CONDITIONAL                                            -*- Autoconf -*-
 
-# Copyright (C) 1997-2017 Free Software Foundation, Inc.
+# Copyright (C) 1997-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/depend.m4 b/m4/depend.m4
index 3b1d4b889..0571cac59 100644
--- a/m4/depend.m4
+++ b/m4/depend.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 1999-2017 Free Software Foundation, Inc.
+# Copyright (C) 1999-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/depout.m4 b/m4/depout.m4
index 5e3f5f768..431c07d3b 100644
--- a/m4/depout.m4
+++ b/m4/depout.m4
@@ -1,12 +1,11 @@
 # Generate code to set up dependency tracking.              -*- Autoconf -*-
 
-# Copyright (C) 1999-2017 Free Software Foundation, Inc.
+# Copyright (C) 1999-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-
 # _AM_OUTPUT_DEPENDENCY_COMMANDS
 # ------------------------------
 AC_DEFUN([_AM_OUTPUT_DEPENDENCY_COMMANDS],
@@ -14,49 +13,41 @@ AC_DEFUN([_AM_OUTPUT_DEPENDENCY_COMMANDS],
   # Older Autoconf quotes --file arguments for eval, but not when files
   # are listed without --file.  Let's play safe and only enable the eval
   # if we detect the quoting.
-  case $CONFIG_FILES in
-  *\'*) eval set x "$CONFIG_FILES" ;;
-  *)   set x $CONFIG_FILES ;;
-  esac
+  # TODO: see whether this extra hack can be removed once we start
+  # requiring Autoconf 2.70 or later.
+  AS_CASE([$CONFIG_FILES],
+          [*\'*], [eval set x "$CONFIG_FILES"],
+          [*], [set x $CONFIG_FILES])
   shift
-  for mf
+  # Used to flag and report bootstrapping failures.
+  am_rc=0
+  for am_mf
   do
     # Strip MF so we end up with the name of the file.
-    mf=`echo "$mf" | sed -e 's/:.*$//'`
-    # Check whether this is an Automake generated Makefile or not.
-    # We used to match only the files named 'Makefile.in', but
-    # some people rename them; so instead we look at the file content.
-    # Grep'ing the first line is not enough: some people post-process
-    # each Makefile.in and add a new line on top of each file to say so.
-    # Grep'ing the whole file is not good either: AIX grep has a line
+    am_mf=`AS_ECHO(["$am_mf"]) | sed -e 's/:.*$//'`
+    # Check whether this is an Automake generated Makefile which includes
+    # dependency-tracking related rules and includes.
+    # Grep'ing the whole file directly is not great: AIX grep has a line
     # limit of 2048, but all sed's we know have understand at least 4000.
-    if sed -n 's,^#.*generated by automake.*,X,p' "$mf" | grep X >/dev/null 2>&1; then
-      dirpart=`AS_DIRNAME("$mf")`
-    else
-      continue
-    fi
-    # Extract the definition of DEPDIR, am__include, and am__quote
-    # from the Makefile without running 'make'.
-    DEPDIR=`sed -n 's/^DEPDIR = //p' < "$mf"`
-    test -z "$DEPDIR" && continue
-    am__include=`sed -n 's/^am__include = //p' < "$mf"`
-    test -z "$am__include" && continue
-    am__quote=`sed -n 's/^am__quote = //p' < "$mf"`
-    # Find all dependency output files, they are included files with
-    # $(DEPDIR) in their names.  We invoke sed twice because it is the
-    # simplest approach to changing $(DEPDIR) to its actual value in the
-    # expansion.
-    for file in `sed -n "
-      s/^$am__include $am__quote\(.*(DEPDIR).*\)$am__quote"'$/\1/p' <"$mf" | \
-	 sed -e 's/\$(DEPDIR)/'"$DEPDIR"'/g'`; do
-      # Make sure the directory exists.
-      test -f "$dirpart/$file" && continue
-      fdir=`AS_DIRNAME(["$file"])`
-      AS_MKDIR_P([$dirpart/$fdir])
-      # echo "creating $dirpart/$file"
-      echo '# dummy' > "$dirpart/$file"
-    done
+    sed -n 's,^am--depfiles:.*,X,p' "$am_mf" | grep X >/dev/null 2>&1 \
+      || continue
+    am_dirpart=`AS_DIRNAME(["$am_mf"])`
+    am_filepart=`AS_BASENAME(["$am_mf"])`
+    AM_RUN_LOG([cd "$am_dirpart" \
+      && sed -e '/# am--include-marker/d' "$am_filepart" \
+        | $MAKE -f - am--depfiles]) || am_rc=$?
   done
+  if test $am_rc -ne 0; then
+    AC_MSG_FAILURE([Something went wrong bootstrapping makefile fragments
+    for automatic dependency tracking.  Try re-running configure with the
+    '--disable-dependency-tracking' option to at least be able to build
+    the package (albeit without support for automatic dependency tracking).])
+  fi
+  AS_UNSET([am_dirpart])
+  AS_UNSET([am_filepart])
+  AS_UNSET([am_mf])
+  AS_UNSET([am_rc])
+  rm -f conftest-deps.mk
 }
 ])# _AM_OUTPUT_DEPENDENCY_COMMANDS
 
@@ -65,11 +56,10 @@ AC_DEFUN([_AM_OUTPUT_DEPENDENCY_COMMANDS],
 # -----------------------------
 # This macro should only be invoked once -- use via AC_REQUIRE.
 #
-# This code is only required when automatic dependency tracking
-# is enabled.  FIXME.  This creates each '.P' file that we will
-# need in order to bootstrap the dependency handling code.
+# This code is only required when automatic dependency tracking is enabled.
+# This creates each '.Po' and '.Plo' makefile fragment that we'll need in
+# order to bootstrap the dependency handling code.
 AC_DEFUN([AM_OUTPUT_DEPENDENCY_COMMANDS],
 [AC_CONFIG_COMMANDS([depfiles],
      [test x"$AMDEP_TRUE" != x"" || _AM_OUTPUT_DEPENDENCY_COMMANDS],
-     [AMDEP_TRUE="$AMDEP_TRUE" ac_aux_dir="$ac_aux_dir"])
-])
+     [AMDEP_TRUE="$AMDEP_TRUE" MAKE="${MAKE-make}"])])
diff --git a/m4/dmalloc.m4 b/m4/dmalloc.m4
index 0b9f8d4f4..03e876a77 100644
--- a/m4/dmalloc.m4
+++ b/m4/dmalloc.m4
@@ -3,7 +3,7 @@
 ## From Franc,ois Pinard               ##
 ## ----------------------------------- ##
 
-# Copyright (C) 1996-2017 Free Software Foundation, Inc.
+# Copyright (C) 1996-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/extra-recurs.m4 b/m4/extra-recurs.m4
index ac7df8eab..1123a9ec0 100644
--- a/m4/extra-recurs.m4
+++ b/m4/extra-recurs.m4
@@ -1,6 +1,6 @@
 # AM_EXTRA_RECURSIVE_TARGETS                                -*- Autoconf -*-
 
-# Copyright (C) 2012-2017 Free Software Foundation, Inc.
+# Copyright (C) 2012-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/gcj.m4 b/m4/gcj.m4
index 413971174..64076e25d 100644
--- a/m4/gcj.m4
+++ b/m4/gcj.m4
@@ -1,7 +1,7 @@
 # Check for Java compiler.                                  -*- Autoconf -*-
 # For now we only handle the GNU compiler.
 
-# Copyright (C) 1999-2017 Free Software Foundation, Inc.
+# Copyright (C) 1999-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/init.m4 b/m4/init.m4
index c84892778..2657797c5 100644
--- a/m4/init.m4
+++ b/m4/init.m4
@@ -1,6 +1,6 @@
 # Do all the work for Automake.                             -*- Autoconf -*-
 
-# Copyright (C) 1996-2017 Free Software Foundation, Inc.
+# Copyright (C) 1996-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -87,8 +87,8 @@ AC_REQUIRE([AM_PROG_INSTALL_STRIP])dnl
 AC_REQUIRE([AC_PROG_MKDIR_P])dnl
 # For better backward compatibility.  To be removed once Automake 1.9.x
 # dies out for good.  For more background, see:
-# <http://lists.gnu.org/archive/html/automake/2012-07/msg00001.html>
-# <http://lists.gnu.org/archive/html/automake/2012-07/msg00014.html>
+# <https://lists.gnu.org/archive/html/automake/2012-07/msg00001.html>
+# <https://lists.gnu.org/archive/html/automake/2012-07/msg00014.html>
 AC_SUBST([mkdir_p], ['$(MKDIR_P)'])
 # We need awk for the "check" target (and possibly the TAP driver).  The
 # system "awk" is bad on some platforms.
@@ -155,7 +155,7 @@ END
 Aborting the configuration process, to ensure you take notice of the issue.
 
 You can download and install GNU coreutils to get an 'rm' implementation
-that behaves properly: <http://www.gnu.org/software/coreutils/>.
+that behaves properly: <https://www.gnu.org/software/coreutils/>.
 
 If you want to complete the configuration process using your problematic
 'rm' anyway, export the environment variable ACCEPT_INFERIOR_RM_PROGRAM
diff --git a/m4/install-sh.m4 b/m4/install-sh.m4
index 94b886a2a..89f27a7bb 100644
--- a/m4/install-sh.m4
+++ b/m4/install-sh.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/internal/ac-config-macro-dirs.m4 b/m4/internal/ac-config-macro-dirs.m4
index cc05bbec5..eaad79c12 100644
--- a/m4/internal/ac-config-macro-dirs.m4
+++ b/m4/internal/ac-config-macro-dirs.m4
@@ -4,7 +4,7 @@
 # FIXME: keep in sync with the contents of the variable
 #        '$ac_config_macro_dirs_fallback' in aclocal.in.
 
-# Copyright (C) 2012-2017 Free Software Foundation, Inc.
+# Copyright (C) 2012-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/lead-dot.m4 b/m4/lead-dot.m4
index a82932169..24f5e6965 100644
--- a/m4/lead-dot.m4
+++ b/m4/lead-dot.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2003-2017 Free Software Foundation, Inc.
+# Copyright (C) 2003-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/lex.m4 b/m4/lex.m4
index d729c3107..f22a32e2c 100644
--- a/m4/lex.m4
+++ b/m4/lex.m4
@@ -1,6 +1,6 @@
 ## Replacement for AC_PROG_LEX.                            -*-  Autoconf -*-
 ## by Alexandre Oliva <oliva@dcc.unicamp.br>
-# Copyright (C) 1998-2017 Free Software Foundation, Inc.
+# Copyright (C) 1998-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/lispdir.m4 b/m4/lispdir.m4
index 846ef3f0e..8e0769d24 100644
--- a/m4/lispdir.m4
+++ b/m4/lispdir.m4
@@ -3,7 +3,7 @@
 ## From Ulrich Drepper
 ## Almost entirely rewritten by Alexandre Oliva
 ## ------------------------
-# Copyright (C) 1996-2017 Free Software Foundation, Inc.
+# Copyright (C) 1996-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/Makefile.inc b/m4/local.mk
index eb5702742..c421dc991 100644
--- a/m4/Makefile.inc
+++ b/m4/local.mk
@@ -1,6 +1,5 @@
-## Included by top-level Makefile for Automake.
-
-## Copyright (C) 1995-2017 Free Software Foundation, Inc.
+## -*- makefile-automake -*-
+## Copyright (C) 1995-2018 Free Software Foundation, Inc.
 ##
 ## This program is free software; you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -13,7 +12,7 @@
 ## GNU General Public License for more details.
 ##
 ## You should have received a copy of the GNU General Public License
-## along with this program.  If not, see <http://www.gnu.org/licenses/>.
+## along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 ## ------------------------------ ##
 ##  Automake-provided m4 macros.  ##
diff --git a/m4/maintainer.m4 b/m4/maintainer.m4
index 33cb24ecc..3d4eeefed 100644
--- a/m4/maintainer.m4
+++ b/m4/maintainer.m4
@@ -1,7 +1,7 @@
 # Add --enable-maintainer-mode option to configure.         -*- Autoconf -*-
 # From Jim Meyering
 
-# Copyright (C) 1996-2017 Free Software Foundation, Inc.
+# Copyright (C) 1996-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/make.m4 b/m4/make.m4
index b3ddca92c..723565d1d 100644
--- a/m4/make.m4
+++ b/m4/make.m4
@@ -1,6 +1,6 @@
 # Check to see how 'make' treats includes.	            -*- Autoconf -*-
 
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -8,42 +8,35 @@
 
 # AM_MAKE_INCLUDE()
 # -----------------
-# Check to see how make treats includes.
+# Check whether make has an 'include' directive that can support all
+# the idioms we need for our automatic dependency tracking code.
 AC_DEFUN([AM_MAKE_INCLUDE],
-[am_make=${MAKE-make}
-cat > confinc << 'END'
+[AC_MSG_CHECKING([whether ${MAKE-make} supports the include directive])
+cat > confinc.mk << 'END'
 am__doit:
-	@echo this is the am__doit target
+	@echo this is the am__doit target >confinc.out
 .PHONY: am__doit
 END
-# If we don't find an include directive, just comment out the code.
-AC_MSG_CHECKING([for style of include used by $am_make])
 am__include="#"
 am__quote=
-_am_result=none
-# First try GNU make style include.
-echo "include confinc" > confmf
-# Ignore all kinds of additional output from 'make'.
-case `$am_make -s -f confmf 2> /dev/null` in #(
-*the\ am__doit\ target*)
-  am__include=include
-  am__quote=
-  _am_result=GNU
-  ;;
-esac
-# Now try BSD make style include.
-if test "$am__include" = "#"; then
-   echo '.include "confinc"' > confmf
-   case `$am_make -s -f confmf 2> /dev/null` in #(
-   *the\ am__doit\ target*)
-     am__include=.include
-     am__quote="\""
-     _am_result=BSD
-     ;;
-   esac
-fi
-AC_SUBST([am__include])
-AC_SUBST([am__quote])
-AC_MSG_RESULT([$_am_result])
-rm -f confinc confmf
-])
+# BSD make does it like this.
+echo '.include "confinc.mk" # ignored' > confmf.BSD
+# Other make implementations (GNU, Solaris 10, AIX) do it like this.
+echo 'include confinc.mk # ignored' > confmf.GNU
+_am_result=no
+for s in GNU BSD; do
+  AM_RUN_LOG([${MAKE-make} -f confmf.$s && cat confinc.out])
+  AS_CASE([$?:`cat confinc.out 2>/dev/null`],
+      ['0:this is the am__doit target'],
+      [AS_CASE([$s],
+          [BSD], [am__include='.include' am__quote='"'],
+          [am__include='include' am__quote=''])])
+  if test "$am__include" != "#"; then
+    _am_result="yes ($s style)"
+    break
+  fi
+done
+rm -f confinc.* confmf.*
+AC_MSG_RESULT([${_am_result}])
+AC_SUBST([am__include])])
+AC_SUBST([am__quote])])
diff --git a/m4/missing.m4 b/m4/missing.m4
index 20be2a5e4..5b43abf0a 100644
--- a/m4/missing.m4
+++ b/m4/missing.m4
@@ -1,6 +1,6 @@
 # Fake the existence of programs that GNU maintainers use.  -*- Autoconf -*-
 
-# Copyright (C) 1997-2017 Free Software Foundation, Inc.
+# Copyright (C) 1997-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/mkdirp.m4 b/m4/mkdirp.m4
index 511f52675..0cdcafa84 100644
--- a/m4/mkdirp.m4
+++ b/m4/mkdirp.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2003-2017 Free Software Foundation, Inc.
+# Copyright (C) 2003-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/obsolete.m4 b/m4/obsolete.m4
index 46e067d89..f8327a48f 100644
--- a/m4/obsolete.m4
+++ b/m4/obsolete.m4
@@ -2,7 +2,7 @@
 # Obsolete and "removed" macros, that must however still report explicit
 # error messages when used, to smooth transition.
 #
-# Copyright (C) 1996-2017 Free Software Foundation, Inc.
+# Copyright (C) 1996-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/options.m4 b/m4/options.m4
index 45cfa546a..90d06172a 100644
--- a/m4/options.m4
+++ b/m4/options.m4
@@ -1,6 +1,6 @@
 # Helper functions for option handling.                     -*- Autoconf -*-
 
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/prog-cc-c-o.m4 b/m4/prog-cc-c-o.m4
index c366078f5..243bb2542 100644
--- a/m4/prog-cc-c-o.m4
+++ b/m4/prog-cc-c-o.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 1999-2017 Free Software Foundation, Inc.
+# Copyright (C) 1999-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/python.m4 b/m4/python.m4
index 6d9e93401..d6dda1363 100644
--- a/m4/python.m4
+++ b/m4/python.m4
@@ -3,7 +3,7 @@
 ## From Andrew Dalke
 ## Updated by James Henstridge
 ## ------------------------
-# Copyright (C) 1999-2017 Free Software Foundation, Inc.
+# Copyright (C) 1999-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -36,10 +36,24 @@ AC_DEFUN([AM_PATH_PYTHON],
  [
   dnl Find a Python interpreter.  Python versions prior to 2.0 are not
   dnl supported. (2.0 was released on October 16, 2000).
-  dnl FIXME: Remove the need to hard-code Python versions here.
+  m4_define_default([am_py_min_ver], m4_ifval([$1], [$1], [2.0]))
+  dnl The arbitrary default maximum version.
+  m4_define_default([am_py_max_ver], [4.0])
+
   m4_define_default([_AM_PYTHON_INTERPRETER_LIST],
-[python python2 python3 python3.5 python3.4 python3.3 python3.2 python3.1 python3.0 python2.7 dnl
- python2.6 python2.5 python2.4 python2.3 python2.2 python2.1 python2.0])
+    [[python] \
+     dnl If we want some Python 2 versions (min version <= 2.7),
+     dnl also search for "python2".
+     m4_if(m4_version_compare(am_py_min_ver, [2.8]), [-1], [python2], []) \
+     [python3] \
+     dnl Construct a comma-separated list of interpreter names (python2.6,
+     dnl python2.7, etc). We only care about the first 3 characters of the
+     dnl version strings (major-dot-minor; not
+     dnl major-dot-minor-dot-bugfix[-dot-whatever])
+     m4_foreach([py_ver],
+       m4_esyscmd_s(seq -s[[", "]] -f["[[%.1f]]"] m4_substr(am_py_max_ver, [0], [3]) -0.1 m4_substr(am_py_min_ver, [0], [3])),
+       dnl Remove python2.8 and python2.9 since they will never exist
+       [m4_bmatch(py_ver, [2.[89]], [], [python]py_ver)])])
 
   AC_ARG_VAR([PYTHON], [the Python interpreter])
 
diff --git a/m4/runlog.m4 b/m4/runlog.m4
index a56b02757..690efc325 100644
--- a/m4/runlog.m4
+++ b/m4/runlog.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/sanity.m4 b/m4/sanity.m4
index 2dbdd213a..eaac218d5 100644
--- a/m4/sanity.m4
+++ b/m4/sanity.m4
@@ -1,6 +1,6 @@
 # Check to make sure that the build environment is sane.    -*- Autoconf -*-
 
-# Copyright (C) 1996-2017 Free Software Foundation, Inc.
+# Copyright (C) 1996-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/silent.m4 b/m4/silent.m4
index 6549ae39f..cf3eca722 100644
--- a/m4/silent.m4
+++ b/m4/silent.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2009-2017 Free Software Foundation, Inc.
+# Copyright (C) 2009-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/strip.m4 b/m4/strip.m4
index 23b822006..3a12c78df 100644
--- a/m4/strip.m4
+++ b/m4/strip.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# Copyright (C) 2001-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/substnot.m4 b/m4/substnot.m4
index f781aa0b8..56eea8a52 100644
--- a/m4/substnot.m4
+++ b/m4/substnot.m4
@@ -1,5 +1,5 @@
 ##                                                          -*- Autoconf -*-
-# Copyright (C) 2006-2017 Free Software Foundation, Inc.
+# Copyright (C) 2006-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/tar.m4 b/m4/tar.m4
index ba4704f47..5de15fea4 100644
--- a/m4/tar.m4
+++ b/m4/tar.m4
@@ -1,6 +1,6 @@
 # Check how to create a tarball.                            -*- Autoconf -*-
 
-# Copyright (C) 2004-2017 Free Software Foundation, Inc.
+# Copyright (C) 2004-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/upc.m4 b/m4/upc.m4
index 60e05ff1b..423d1219d 100644
--- a/m4/upc.m4
+++ b/m4/upc.m4
@@ -1,6 +1,6 @@
 # Find a compiler for Unified Parallel C.	            -*- Autoconf -*-
 
-# Copyright (C) 2006-2017 Free Software Foundation, Inc.
+# Copyright (C) 2006-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
diff --git a/m4/vala.m4 b/m4/vala.m4
index 8b742d1c5..01aee694e 100644
--- a/m4/vala.m4
+++ b/m4/vala.m4
@@ -1,6 +1,6 @@
 # Autoconf support for the Vala compiler
 
-# Copyright (C) 2008-2017 Free Software Foundation, Inc.
+# Copyright (C) 2008-2018 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,