m4: Update macros from autoconf-archive

One of the downsides of keeping the macros in-tree is that they
periodically need updating.

15 files changed, 285 insertions, 390 deletions

diff --git a/m4/ax_append_compile_flags.m4 b/m4/ax_append_compile_flags.m4
index 2bb27ef..9c85635 100644
--- a/m4/ax_append_compile_flags.m4
+++ b/m4/ax_append_compile_flags.m4
@@ -1,6 +1,6 @@
-# ===========================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
-# ===========================================================================
+# ============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
+# ============================================================================
 #
 # SYNOPSIS
 #
@@ -30,33 +30,12 @@
 #
 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
 #
-#   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 the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 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/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
 
-#serial 5
+#serial 7
 
 AC_DEFUN([AX_APPEND_COMPILE_FLAGS],
 [AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
diff --git a/m4/ax_append_flag.m4 b/m4/ax_append_flag.m4
index 08f2e07..dd6d8b6 100644
--- a/m4/ax_append_flag.m4
+++ b/m4/ax_append_flag.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_append_flag.html
+#      https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -23,33 +23,12 @@
 #   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
 #
-#   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 the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 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/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
 
-#serial 6
+#serial 8
 
 AC_DEFUN([AX_APPEND_FLAG],
 [dnl
diff --git a/m4/ax_append_link_flags.m4 b/m4/ax_append_link_flags.m4
index fd70fc7..99b9fa5 100644
--- a/m4/ax_append_link_flags.m4
+++ b/m4/ax_append_link_flags.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
+#   https://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -28,33 +28,12 @@
 #
 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
 #
-#   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 the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 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/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
 
-#serial 5
+#serial 7
 
 AC_DEFUN([AX_APPEND_LINK_FLAGS],
 [AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4
index ca36397..bd753b3 100644
--- a/m4/ax_check_compile_flag.m4
+++ b/m4/ax_check_compile_flag.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+#  https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -29,33 +29,12 @@
 #   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
 #
-#   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 the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 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/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
 
-#serial 4
+#serial 6
 
 AC_DEFUN([AX_CHECK_COMPILE_FLAG],
 [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
diff --git a/m4/ax_check_enable_debug.m4 b/m4/ax_check_enable_debug.m4
index f99d75f..7bc7710 100644
--- a/m4/ax_check_enable_debug.m4
+++ b/m4/ax_check_enable_debug.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_check_enable_debug.html
+#  https://www.gnu.org/software/autoconf-archive/ax_check_enable_debug.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -42,7 +42,7 @@
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved.
 
-#serial 5
+#serial 9
 
 AC_DEFUN([AX_CHECK_ENABLE_DEBUG],[
     AC_BEFORE([$0],[AC_PROG_CC])dnl
@@ -65,8 +65,8 @@ AC_DEFUN([AX_CHECK_ENABLE_DEBUG],[
     m4_define(ax_disable_debug_vars,[m4_normalize(ifelse([$3],,[NDEBUG],[$3]))])
 
     AC_ARG_ENABLE(debug,
-	[AS_HELP_STRING([--enable-debug=]@<:@yes/info/profile/no@:>@,[compile with debugging])],
-	[],enable_debug=$ax_enable_debug_default)
+        [AS_HELP_STRING([--enable-debug=]@<:@yes/info/profile/no@:>@,[compile with debugging])],
+        [],enable_debug=$ax_enable_debug_default)
 
     # empty mean debug yes
     AS_IF([test "x$enable_debug" = "x"],
@@ -75,50 +75,50 @@ AC_DEFUN([AX_CHECK_ENABLE_DEBUG],[
     # case of debug
     AS_CASE([$enable_debug],
       [yes],[
-	AC_MSG_RESULT(yes)
-	CFLAGS="${CFLAGS} -g -O0"
-	CXXFLAGS="${CXXFLAGS} -g -O0"
-	FFLAGS="${FFLAGS} -g -O0"
-	FCFLAGS="${FCFLAGS} -g -O0"
-	OBJCFLAGS="${OBJCFLAGS} -g -O0"
+        AC_MSG_RESULT(yes)
+        CFLAGS="${CFLAGS} -g -O0"
+        CXXFLAGS="${CXXFLAGS} -g -O0"
+        FFLAGS="${FFLAGS} -g -O0"
+        FCFLAGS="${FCFLAGS} -g -O0"
+        OBJCFLAGS="${OBJCFLAGS} -g -O0"
       ],
       [info],[
-	AC_MSG_RESULT(info)
-	CFLAGS="${CFLAGS} -g"
-	CXXFLAGS="${CXXFLAGS} -g"
-	FFLAGS="${FFLAGS} -g"
-	FCFLAGS="${FCFLAGS} -g"
-	OBJCFLAGS="${OBJCFLAGS} -g"
+        AC_MSG_RESULT(info)
+        CFLAGS="${CFLAGS} -g"
+        CXXFLAGS="${CXXFLAGS} -g"
+        FFLAGS="${FFLAGS} -g"
+        FCFLAGS="${FCFLAGS} -g"
+        OBJCFLAGS="${OBJCFLAGS} -g"
       ],
       [profile],[
-	AC_MSG_RESULT(profile)
-	CFLAGS="${CFLAGS} -g -pg"
-	CXXFLAGS="${CXXFLAGS} -g -pg"
-	FFLAGS="${FFLAGS} -g -pg"
-	FCFLAGS="${FCFLAGS} -g -pg"
-	OBJCFLAGS="${OBJCFLAGS} -g -pg"
-	LDFLAGS="${LDFLAGS} -pg"
+        AC_MSG_RESULT(profile)
+        CFLAGS="${CFLAGS} -g -pg"
+        CXXFLAGS="${CXXFLAGS} -g -pg"
+        FFLAGS="${FFLAGS} -g -pg"
+        FCFLAGS="${FCFLAGS} -g -pg"
+        OBJCFLAGS="${OBJCFLAGS} -g -pg"
+        LDFLAGS="${LDFLAGS} -pg"
       ],
       [
-	AC_MSG_RESULT(no)
-	dnl Ensure AC_PROG_CC/CXX/F77/FC/OBJC will not enable debug flags
-	dnl by setting any unset environment flag variables
-	AS_IF([test "x${CFLAGS+set}" != "xset"],
-	  [CFLAGS=""])
-	AS_IF([test "x${CXXFLAGS+set}" != "xset"],
-	  [CXXFLAGS=""])
-	AS_IF([test "x${FFLAGS+set}" != "xset"],
-	  [FFLAGS=""])
-	AS_IF([test "x${FCFLAGS+set}" != "xset"],
-	  [FCFLAGS=""])
-	AS_IF([test "x${OBJCFLAGS+set}" != "xset"],
-	  [OBJCFLAGS=""])
+        AC_MSG_RESULT(no)
+        dnl Ensure AC_PROG_CC/CXX/F77/FC/OBJC will not enable debug flags
+        dnl by setting any unset environment flag variables
+        AS_IF([test "x${CFLAGS+set}" != "xset"],
+          [CFLAGS=""])
+        AS_IF([test "x${CXXFLAGS+set}" != "xset"],
+          [CXXFLAGS=""])
+        AS_IF([test "x${FFLAGS+set}" != "xset"],
+          [FFLAGS=""])
+        AS_IF([test "x${FCFLAGS+set}" != "xset"],
+          [FCFLAGS=""])
+        AS_IF([test "x${OBJCFLAGS+set}" != "xset"],
+          [OBJCFLAGS=""])
       ])
 
     dnl Define various variables if debugging is disabled.
     dnl assert.h is a NOP if NDEBUG is defined, so define it by default.
     AS_IF([test "x$enable_debug" = "xyes"],
-      [m4_map_args_w(ax_enable_debug_vars, [AC_DEFINE(], [,,[Define if debugging is enabled])])],
-      [m4_map_args_w(ax_disable_debug_vars, [AC_DEFINE(], [,,[Define if debugging is disabled])])])
+      [m4_map_args_w(ax_enable_debug_vars, [AC_DEFINE(], [,[1],[Define if debugging is enabled])])],
+      [m4_map_args_w(ax_disable_debug_vars, [AC_DEFINE(], [,[1],[Define if debugging is disabled])])])
     ax_enable_debug=$enable_debug
 ])
diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
index eb01a6c..03a30ce 100644
--- a/m4/ax_check_link_flag.m4
+++ b/m4/ax_check_link_flag.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+#    https://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -29,33 +29,12 @@
 #   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
 #   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
 #
-#   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 the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 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/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
 
-#serial 4
+#serial 6
 
 AC_DEFUN([AX_CHECK_LINK_FLAG],
 [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
diff --git a/m4/ax_code_coverage.m4 b/m4/ax_code_coverage.m4
index a257469..3d36924 100644
--- a/m4/ax_code_coverage.m4
+++ b/m4/ax_code_coverage.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_code_coverage.html
+#     https://www.gnu.org/software/autoconf-archive/ax_code_coverage.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -12,16 +12,16 @@
 #   CODE_COVERAGE_CXXFLAGS and CODE_COVERAGE_LIBS which should be included
 #   in the CPPFLAGS, CFLAGS CXXFLAGS and LIBS/LIBADD variables of every
 #   build target (program or library) which should be built with code
-#   coverage support. Also defines CODE_COVERAGE_RULES which should be
-#   substituted in your Makefile; and $enable_code_coverage which can be
-#   used in subsequent configure output. CODE_COVERAGE_ENABLED is defined
-#   and substituted, and corresponds to the value of the
-#   --enable-code-coverage option, which defaults to being disabled.
+#   coverage support. Also add rules using AX_ADD_AM_MACRO_STATIC; and
+#   $enable_code_coverage which can be used in subsequent configure output.
+#   CODE_COVERAGE_ENABLED is defined and substituted, and corresponds to the
+#   value of the --enable-code-coverage option, which defaults to being
+#   disabled.
 #
 #   Test also for gcov program and create GCOV variable that could be
 #   substituted.
 #
-#   Note that all optimisation flags in CFLAGS must be disabled when code
+#   Note that all optimization flags in CFLAGS must be disabled when code
 #   coverage is enabled.
 #
 #   Usage example:
@@ -32,25 +32,24 @@
 #
 #   Makefile.am:
 #
-#     @CODE_COVERAGE_RULES@
+#     include $(top_srcdir)/aminclude_static.am
+#
 #     my_program_LIBS = ... $(CODE_COVERAGE_LIBS) ...
 #     my_program_CPPFLAGS = ... $(CODE_COVERAGE_CPPFLAGS) ...
 #     my_program_CFLAGS = ... $(CODE_COVERAGE_CFLAGS) ...
 #     my_program_CXXFLAGS = ... $(CODE_COVERAGE_CXXFLAGS) ...
 #
-#   This results in a "check-code-coverage" rule being added to any
-#   Makefile.am which includes "@CODE_COVERAGE_RULES@" (assuming the module
-#   has been configured with --enable-code-coverage). Running `make
-#   check-code-coverage` in that directory will run the module's test suite
-#   (`make check`) and build a code coverage report detailing the code which
-#   was touched, then print the URI for the report.
+#     clean-local: code-coverage-clean
+#     distclean-local: code-coverage-dist-clean
 #
-#   In earlier versions of this macro, CODE_COVERAGE_LDFLAGS was defined
-#   instead of CODE_COVERAGE_LIBS. They are both still defined, but use of
-#   CODE_COVERAGE_LIBS is preferred for clarity; CODE_COVERAGE_LDFLAGS is
-#   deprecated. They have the same value.
+#   This results in a "check-code-coverage" rule being added to any
+#   Makefile.am which do "include $(top_srcdir)/aminclude_static.am"
+#   (assuming the module has been configured with --enable-code-coverage).
+#   Running `make check-code-coverage` in that directory will run the
+#   module's test suite (`make check`) and build a code coverage report
+#   detailing the code which was touched, then print the URI for the report.
 #
-#   This code was derived from Makefile.decl in GLib, originally licenced
+#   This code was derived from Makefile.decl in GLib, originally licensed
 #   under LGPLv2.1+.
 #
 # LICENSE
@@ -60,7 +59,7 @@
 #   Copyright (c) 2012 Christian Persch
 #   Copyright (c) 2012 Paolo Borelli
 #   Copyright (c) 2012 Dan Winship
-#   Copyright (c) 2015 Bastien ROUCARIES
+#   Copyright (c) 2015,2018 Bastien ROUCARIES
 #
 #   This library is free software; you can redistribute it and/or modify it
 #   under the terms of the GNU Lesser General Public License as published by
@@ -73,109 +72,24 @@
 #   General Public License for more details.
 #
 #   You should have received a copy of the GNU Lesser General Public License
-#   along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-#serial 20
-
-AC_DEFUN([AX_CODE_COVERAGE],[
-	dnl Check for --enable-code-coverage
-	AC_REQUIRE([AC_PROG_SED])
-
-	# allow to override gcov location
-	AC_ARG_WITH([gcov],
-	  [AS_HELP_STRING([--with-gcov[=GCOV]], [use given GCOV for coverage (GCOV=gcov).])],
-	  [_AX_CODE_COVERAGE_GCOV_PROG_WITH=$with_gcov],
-	  [_AX_CODE_COVERAGE_GCOV_PROG_WITH=gcov])
+#   along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-	AC_MSG_CHECKING([whether to build with code coverage support])
-	AC_ARG_ENABLE([code-coverage],
-	  AS_HELP_STRING([--enable-code-coverage],
-	  [Whether to enable code coverage support]),,
-	  enable_code_coverage=no)
+#serial 32
 
-	AM_CONDITIONAL([CODE_COVERAGE_ENABLED], [test x$enable_code_coverage = xyes])
-	AC_SUBST([CODE_COVERAGE_ENABLED], [$enable_code_coverage])
-	AC_MSG_RESULT($enable_code_coverage)
-
-	AS_IF([ test "$enable_code_coverage" = "yes" ], [
-		# check for gcov
-		AC_CHECK_TOOL([GCOV],
-		  [$_AX_CODE_COVERAGE_GCOV_PROG_WITH],
-		  [:])
-		AS_IF([test "X$GCOV" = "X:"],
-		  [AC_MSG_ERROR([gcov is needed to do coverage])])
-		AC_SUBST([GCOV])
-
-		dnl Check if gcc is being used
-		AS_IF([ test "$GCC" = "no" ], [
-			AC_MSG_ERROR([not compiling with gcc, which is required for gcov code coverage])
-		])
-
-		AC_CHECK_PROG([LCOV], [lcov], [lcov])
-		AC_CHECK_PROG([GENHTML], [genhtml], [genhtml])
-
-		AS_IF([ test -z "$LCOV" ], [
-			AC_MSG_ERROR([To enable code coverage reporting you must have lcov installed])
-		])
-
-		AS_IF([ test -z "$GENHTML" ], [
-			AC_MSG_ERROR([Could not find genhtml from the lcov package])
-		])
-
-		dnl Build the code coverage flags
-		dnl Define CODE_COVERAGE_LDFLAGS for backwards compatibility
-		CODE_COVERAGE_CPPFLAGS="-DNDEBUG"
-		CODE_COVERAGE_CFLAGS="-O0 -g -fprofile-arcs -ftest-coverage"
-		CODE_COVERAGE_CXXFLAGS="-O0 -g -fprofile-arcs -ftest-coverage"
-		CODE_COVERAGE_LIBS="-lgcov"
-		CODE_COVERAGE_LDFLAGS="$CODE_COVERAGE_LIBS"
-
-		AC_SUBST([CODE_COVERAGE_CPPFLAGS])
-		AC_SUBST([CODE_COVERAGE_CFLAGS])
-		AC_SUBST([CODE_COVERAGE_CXXFLAGS])
-		AC_SUBST([CODE_COVERAGE_LIBS])
-		AC_SUBST([CODE_COVERAGE_LDFLAGS])
-
-		[CODE_COVERAGE_RULES_CHECK='
-	-$(A''M_V_at)$(MAKE) $(AM_MAKEFLAGS) -k check
-	$(A''M_V_at)$(MAKE) $(AM_MAKEFLAGS) code-coverage-capture
-']
-		[CODE_COVERAGE_RULES_CAPTURE='
-	$(code_coverage_v_lcov_cap)$(LCOV) $(code_coverage_quiet) $(addprefix --directory ,$(CODE_COVERAGE_DIRECTORY)) --capture --output-file "$(CODE_COVERAGE_OUTPUT_FILE).tmp" --test-name "$(call code_coverage_sanitize,$(PACKAGE_NAME)-$(PACKAGE_VERSION))" --no-checksum --compat-libtool $(CODE_COVERAGE_LCOV_SHOPTS) $(CODE_COVERAGE_LCOV_OPTIONS)
-	$(code_coverage_v_lcov_ign)$(LCOV) $(code_coverage_quiet) $(addprefix --directory ,$(CODE_COVERAGE_DIRECTORY)) --remove "$(CODE_COVERAGE_OUTPUT_FILE).tmp" "/tmp/*" $(CODE_COVERAGE_IGNORE_PATTERN) --output-file "$(CODE_COVERAGE_OUTPUT_FILE)" $(CODE_COVERAGE_LCOV_SHOPTS) $(CODE_COVERAGE_LCOV_RMOPTS)
-	-@rm -f $(CODE_COVERAGE_OUTPUT_FILE).tmp
-	$(code_coverage_v_genhtml)LANG=C $(GENHTML) $(code_coverage_quiet) $(addprefix --prefix ,$(CODE_COVERAGE_DIRECTORY)) --output-directory "$(CODE_COVERAGE_OUTPUT_DIRECTORY)" --title "$(PACKAGE_NAME)-$(PACKAGE_VERSION) Code Coverage" --legend --show-details "$(CODE_COVERAGE_OUTPUT_FILE)" $(CODE_COVERAGE_GENHTML_OPTIONS)
-	@echo "file://$(abs_builddir)/$(CODE_COVERAGE_OUTPUT_DIRECTORY)/index.html"
-']
-		[CODE_COVERAGE_RULES_CLEAN='
-clean: code-coverage-clean
-distclean: code-coverage-clean
-code-coverage-clean:
-	-$(LCOV) --directory $(top_builddir) -z
-	-rm -rf $(CODE_COVERAGE_OUTPUT_FILE) $(CODE_COVERAGE_OUTPUT_FILE).tmp $(CODE_COVERAGE_OUTPUT_DIRECTORY)
-	-find . \( -name "*.gcda" -o -name "*.gcno" -o -name "*.gcov" \) -delete
-']
-	], [
-		[CODE_COVERAGE_RULES_CHECK='
-	@echo "Need to reconfigure with --enable-code-coverage"
-']
-		CODE_COVERAGE_RULES_CAPTURE="$CODE_COVERAGE_RULES_CHECK"
-		CODE_COVERAGE_RULES_CLEAN=''
-	])
-
-[CODE_COVERAGE_RULES='
+m4_define(_AX_CODE_COVERAGE_RULES,[
+AX_ADD_AM_MACRO_STATIC([
 # Code coverage
 #
 # Optional:
 #  - CODE_COVERAGE_DIRECTORY: Top-level directory for code coverage reporting.
 #    Multiple directories may be specified, separated by whitespace.
-#    (Default: $(top_builddir))
+#    (Default: \$(top_builddir))
 #  - CODE_COVERAGE_OUTPUT_FILE: Filename and path for the .info file generated
 #    by lcov for code coverage. (Default:
-#    $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage.info)
+#    \$(PACKAGE_NAME)-\$(PACKAGE_VERSION)-coverage.info)
 #  - CODE_COVERAGE_OUTPUT_DIRECTORY: Directory for generated code coverage
 #    reports to be created. (Default:
-#    $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage)
+#    \$(PACKAGE_NAME)-\$(PACKAGE_VERSION)-coverage)
 #  - CODE_COVERAGE_BRANCH_COVERAGE: Set to 1 to enforce branch coverage,
 #    set to 0 to disable it and leave empty to stay with the default.
 #    (Default: empty)
@@ -198,67 +112,161 @@ code-coverage-clean:
 #    instance. (Default: $CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT)
 #  - CODE_COVERAGE_IGNORE_PATTERN: Extra glob pattern of files to ignore
 #
-# The generated report will be titled using the $(PACKAGE_NAME) and
-# $(PACKAGE_VERSION). In order to add the current git hash to the title,
+# The generated report will be titled using the \$(PACKAGE_NAME) and
+# \$(PACKAGE_VERSION). In order to add the current git hash to the title,
 # use the git-version-gen script, available online.
-
 # Optional variables
-CODE_COVERAGE_DIRECTORY ?= $(top_builddir)
-CODE_COVERAGE_OUTPUT_FILE ?= $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage.info
-CODE_COVERAGE_OUTPUT_DIRECTORY ?= $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage
+# run only on top dir
+if CODE_COVERAGE_ENABLED
+ ifeq (\$(abs_builddir), \$(abs_top_builddir))
+CODE_COVERAGE_DIRECTORY ?= \$(top_builddir)
+CODE_COVERAGE_OUTPUT_FILE ?= \$(PACKAGE_NAME)-\$(PACKAGE_VERSION)-coverage.info
+CODE_COVERAGE_OUTPUT_DIRECTORY ?= \$(PACKAGE_NAME)-\$(PACKAGE_VERSION)-coverage
+
 CODE_COVERAGE_BRANCH_COVERAGE ?=
-CODE_COVERAGE_LCOV_SHOPTS_DEFAULT ?= $(if $(CODE_COVERAGE_BRANCH_COVERAGE),\
---rc lcov_branch_coverage=$(CODE_COVERAGE_BRANCH_COVERAGE))
-CODE_COVERAGE_LCOV_SHOPTS ?= $(CODE_COVERAGE_LCOV_SHOPTS_DEFAULT)
-CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH ?= --gcov-tool "$(GCOV)"
-CODE_COVERAGE_LCOV_OPTIONS_DEFAULT ?= $(CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH)
-CODE_COVERAGE_LCOV_OPTIONS ?= $(CODE_COVERAGE_LCOV_OPTIONS_DEFAULT)
+CODE_COVERAGE_LCOV_SHOPTS_DEFAULT ?= \$(if \$(CODE_COVERAGE_BRANCH_COVERAGE),\
+--rc lcov_branch_coverage=\$(CODE_COVERAGE_BRANCH_COVERAGE))
+CODE_COVERAGE_LCOV_SHOPTS ?= \$(CODE_COVERAGE_LCOV_SHOPTS_DEFAULT)
+CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH ?= --gcov-tool \"\$(GCOV)\"
+CODE_COVERAGE_LCOV_OPTIONS_DEFAULT ?= \$(CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH)
+CODE_COVERAGE_LCOV_OPTIONS ?= \$(CODE_COVERAGE_LCOV_OPTIONS_DEFAULT)
 CODE_COVERAGE_LCOV_RMOPTS_DEFAULT ?=
-CODE_COVERAGE_LCOV_RMOPTS ?= $(CODE_COVERAGE_LCOV_RMOPTS_DEFAULT)
+CODE_COVERAGE_LCOV_RMOPTS ?= \$(CODE_COVERAGE_LCOV_RMOPTS_DEFAULT)
 CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT ?=\
-$(if $(CODE_COVERAGE_BRANCH_COVERAGE),\
---rc genhtml_branch_coverage=$(CODE_COVERAGE_BRANCH_COVERAGE))
-CODE_COVERAGE_GENHTML_OPTIONS ?= $(CODE_COVERAGE_GENHTML_OPTIONS_DEFAULTS)
+\$(if \$(CODE_COVERAGE_BRANCH_COVERAGE),\
+--rc genhtml_branch_coverage=\$(CODE_COVERAGE_BRANCH_COVERAGE))
+CODE_COVERAGE_GENHTML_OPTIONS ?= \$(CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT)
 CODE_COVERAGE_IGNORE_PATTERN ?=
 
-code_coverage_v_lcov_cap = $(code_coverage_v_lcov_cap_$(V))
-code_coverage_v_lcov_cap_ = $(code_coverage_v_lcov_cap_$(AM_DEFAULT_VERBOSITY))
-code_coverage_v_lcov_cap_0 = @echo "  LCOV   --capture"\
- $(CODE_COVERAGE_OUTPUT_FILE);
-code_coverage_v_lcov_ign = $(code_coverage_v_lcov_ign_$(V))
-code_coverage_v_lcov_ign_ = $(code_coverage_v_lcov_ign_$(AM_DEFAULT_VERBOSITY))
-code_coverage_v_lcov_ign_0 = @echo "  LCOV   --remove /tmp/*"\
- $(CODE_COVERAGE_IGNORE_PATTERN);
-code_coverage_v_genhtml = $(code_coverage_v_genhtml_$(V))
-code_coverage_v_genhtml_ = $(code_coverage_v_genhtml_$(AM_DEFAULT_VERBOSITY))
-code_coverage_v_genhtml_0 = @echo "  GEN   " $(CODE_COVERAGE_OUTPUT_DIRECTORY);
-code_coverage_quiet = $(code_coverage_quiet_$(V))
-code_coverage_quiet_ = $(code_coverage_quiet_$(AM_DEFAULT_VERBOSITY))
+GITIGNOREFILES = \$(GITIGNOREFILES) \$(CODE_COVERAGE_OUTPUT_FILE) \$(CODE_COVERAGE_OUTPUT_DIRECTORY)
+code_coverage_v_lcov_cap = \$(code_coverage_v_lcov_cap_\$(V))
+code_coverage_v_lcov_cap_ = \$(code_coverage_v_lcov_cap_\$(AM_DEFAULT_VERBOSITY))
+code_coverage_v_lcov_cap_0 = @echo \"  LCOV   --capture\" \$(CODE_COVERAGE_OUTPUT_FILE);
+code_coverage_v_lcov_ign = \$(code_coverage_v_lcov_ign_\$(V))
+code_coverage_v_lcov_ign_ = \$(code_coverage_v_lcov_ign_\$(AM_DEFAULT_VERBOSITY))
+code_coverage_v_lcov_ign_0 = @echo \"  LCOV   --remove /tmp/*\" \$(CODE_COVERAGE_IGNORE_PATTERN);
+code_coverage_v_genhtml = \$(code_coverage_v_genhtml_\$(V))
+code_coverage_v_genhtml_ = \$(code_coverage_v_genhtml_\$(AM_DEFAULT_VERBOSITY))
+code_coverage_v_genhtml_0 = @echo \"  GEN   \" \"\$(CODE_COVERAGE_OUTPUT_DIRECTORY)\";
+code_coverage_quiet = \$(code_coverage_quiet_\$(V))
+code_coverage_quiet_ = \$(code_coverage_quiet_\$(AM_DEFAULT_VERBOSITY))
 code_coverage_quiet_0 = --quiet
 
 # sanitizes the test-name: replaces with underscores: dashes and dots
-code_coverage_sanitize = $(subst -,_,$(subst .,_,$(1)))
+code_coverage_sanitize = \$(subst -,_,\$(subst .,_,\$(1)))
 
 # Use recursive makes in order to ignore errors during check
-check-code-coverage:'"$CODE_COVERAGE_RULES_CHECK"'
+check-code-coverage:
+	-\$(AM_V_at)\$(MAKE) \$(AM_MAKEFLAGS) -k check
+	\$(AM_V_at)\$(MAKE) \$(AM_MAKEFLAGS) code-coverage-capture
 
 # Capture code coverage data
-code-coverage-capture: code-coverage-capture-hook'"$CODE_COVERAGE_RULES_CAPTURE"'
+code-coverage-capture: code-coverage-capture-hook
+	\$(code_coverage_v_lcov_cap)\$(LCOV) \$(code_coverage_quiet) \$(addprefix --directory ,\$(CODE_COVERAGE_DIRECTORY)) --capture --output-file \"\$(CODE_COVERAGE_OUTPUT_FILE).tmp\" --test-name \"\$(call code_coverage_sanitize,\$(PACKAGE_NAME)-\$(PACKAGE_VERSION))\" --no-checksum --compat-libtool \$(CODE_COVERAGE_LCOV_SHOPTS) \$(CODE_COVERAGE_LCOV_OPTIONS)
+	\$(code_coverage_v_lcov_ign)\$(LCOV) \$(code_coverage_quiet) \$(addprefix --directory ,\$(CODE_COVERAGE_DIRECTORY)) --remove \"\$(CODE_COVERAGE_OUTPUT_FILE).tmp\" \"/tmp/*\" \$(CODE_COVERAGE_IGNORE_PATTERN) --output-file \"\$(CODE_COVERAGE_OUTPUT_FILE)\" \$(CODE_COVERAGE_LCOV_SHOPTS) \$(CODE_COVERAGE_LCOV_RMOPTS)
+	-@rm -f \"\$(CODE_COVERAGE_OUTPUT_FILE).tmp\"
+	\$(code_coverage_v_genhtml)LANG=C \$(GENHTML) \$(code_coverage_quiet) \$(addprefix --prefix ,\$(CODE_COVERAGE_DIRECTORY)) --output-directory \"\$(CODE_COVERAGE_OUTPUT_DIRECTORY)\" --title \"\$(PACKAGE_NAME)-\$(PACKAGE_VERSION) Code Coverage\" --legend --show-details \"\$(CODE_COVERAGE_OUTPUT_FILE)\" \$(CODE_COVERAGE_GENHTML_OPTIONS)
+	@echo \"file://\$(abs_builddir)/\$(CODE_COVERAGE_OUTPUT_DIRECTORY)/index.html\"
+
+code-coverage-clean:
+	-\$(LCOV) --directory \$(top_builddir) -z
+	-rm -rf \"\$(CODE_COVERAGE_OUTPUT_FILE)\" \"\$(CODE_COVERAGE_OUTPUT_FILE).tmp\" \"\$(CODE_COVERAGE_OUTPUT_DIRECTORY)\"
+	-find . \\( -name \"*.gcda\" -o -name \"*.gcno\" -o -name \"*.gcov\" \\) -delete
+
+code-coverage-dist-clean:
+
+A][M_DISTCHECK_CONFIGURE_FLAGS = \$(A][M_DISTCHECK_CONFIGURE_FLAGS) --disable-code-coverage
+ else # ifneq (\$(abs_builddir), \$(abs_top_builddir))
+check-code-coverage:
 
+code-coverage-capture: code-coverage-capture-hook
+
+code-coverage-clean:
+
+code-coverage-dist-clean:
+ endif # ifeq (\$(abs_builddir), \$(abs_top_builddir))
+else #! CODE_COVERAGE_ENABLED
+# Use recursive makes in order to ignore errors during check
+check-code-coverage:
+	@echo \"Need to reconfigure with --enable-code-coverage\"
+# Capture code coverage data
+code-coverage-capture: code-coverage-capture-hook
+	@echo \"Need to reconfigure with --enable-code-coverage\"
+
+code-coverage-clean:
+
+code-coverage-dist-clean:
+
+endif #CODE_COVERAGE_ENABLED
 # Hook rule executed before code-coverage-capture, overridable by the user
 code-coverage-capture-hook:
 
-'"$CODE_COVERAGE_RULES_CLEAN"'
+.PHONY: check-code-coverage code-coverage-capture code-coverage-dist-clean code-coverage-clean code-coverage-capture-hook
+])
+])
+
+AC_DEFUN([_AX_CODE_COVERAGE_ENABLED],[
+	AX_CHECK_GNU_MAKE([],[AC_MSG_ERROR([not using GNU make that is needed for coverage])])
+	AC_REQUIRE([AX_ADD_AM_MACRO_STATIC])
+	# check for gcov
+	AC_CHECK_TOOL([GCOV],
+		  [$_AX_CODE_COVERAGE_GCOV_PROG_WITH],
+		  [:])
+	AS_IF([test "X$GCOV" = "X:"],
+	      [AC_MSG_ERROR([gcov is needed to do coverage])])
+	AC_SUBST([GCOV])
+
+	dnl Check if gcc is being used
+	AS_IF([ test "$GCC" = "no" ], [
+		AC_MSG_ERROR([not compiling with gcc, which is required for gcov code coverage])
+	      ])
+
+	AC_CHECK_PROG([LCOV], [lcov], [lcov])
+	AC_CHECK_PROG([GENHTML], [genhtml], [genhtml])
+
+	AS_IF([ test x"$LCOV" = x ], [
+		AC_MSG_ERROR([To enable code coverage reporting you must have lcov installed])
+	      ])
+
+	AS_IF([ test x"$GENHTML" = x ], [
+		AC_MSG_ERROR([Could not find genhtml from the lcov package])
+	])
+
+	dnl Build the code coverage flags
+	dnl Define CODE_COVERAGE_LDFLAGS for backwards compatibility
+	CODE_COVERAGE_CPPFLAGS="-DNDEBUG"
+	CODE_COVERAGE_CFLAGS="-O0 -g -fprofile-arcs -ftest-coverage"
+	CODE_COVERAGE_CXXFLAGS="-O0 -g -fprofile-arcs -ftest-coverage"
+	CODE_COVERAGE_LIBS="-lgcov"
+
+	AC_SUBST([CODE_COVERAGE_CPPFLAGS])
+	AC_SUBST([CODE_COVERAGE_CFLAGS])
+	AC_SUBST([CODE_COVERAGE_CXXFLAGS])
+	AC_SUBST([CODE_COVERAGE_LIBS])
+])
 
-GITIGNOREFILES ?=
-GITIGNOREFILES += $(CODE_COVERAGE_OUTPUT_FILE) $(CODE_COVERAGE_OUTPUT_DIRECTORY)
+AC_DEFUN([AX_CODE_COVERAGE],[
+	dnl Check for --enable-code-coverage
 
-A''M_DISTCHECK_CONFIGURE_FLAGS ?=
-A''M_DISTCHECK_CONFIGURE_FLAGS += --disable-code-coverage
+	# allow to override gcov location
+	AC_ARG_WITH([gcov],
+	  [AS_HELP_STRING([--with-gcov[=GCOV]], [use given GCOV for coverage (GCOV=gcov).])],
+	  [_AX_CODE_COVERAGE_GCOV_PROG_WITH=$with_gcov],
+	  [_AX_CODE_COVERAGE_GCOV_PROG_WITH=gcov])
+
+	AC_MSG_CHECKING([whether to build with code coverage support])
+	AC_ARG_ENABLE([code-coverage],
+	  AS_HELP_STRING([--enable-code-coverage],
+	  [Whether to enable code coverage support]),,
+	  enable_code_coverage=no)
+
+	AM_CONDITIONAL([CODE_COVERAGE_ENABLED], [test "x$enable_code_coverage" = xyes])
+	AC_SUBST([CODE_COVERAGE_ENABLED], [$enable_code_coverage])
+	AC_MSG_RESULT($enable_code_coverage)
 
-.PHONY: check-code-coverage code-coverage-capture code-coverage-capture-hook code-coverage-clean
-']
+	AS_IF([ test "x$enable_code_coverage" = xyes ], [
+		_AX_CODE_COVERAGE_ENABLED
+	      ])
 
-	AC_SUBST([CODE_COVERAGE_RULES])
-	m4_ifdef([_AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE([CODE_COVERAGE_RULES])])
+	_AX_CODE_COVERAGE_RULES
 ])
diff --git a/m4/ax_compiler_flags_cxxflags.m4 b/m4/ax_compiler_flags_cxxflags.m4
index d702aac..3067d9b 100644
--- a/m4/ax_compiler_flags_cxxflags.m4
+++ b/m4/ax_compiler_flags_cxxflags.m4
@@ -1,6 +1,6 @@
-# ==============================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_cxxflags.html
-# ==============================================================================
+# ===============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_compiler_flags_cxxflags.html
+# ===============================================================================
 #
 # SYNOPSIS
 #
@@ -26,7 +26,7 @@
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 8
+#serial 10
 
 AC_DEFUN([AX_COMPILER_FLAGS_CXXFLAGS],[
     AC_REQUIRE([AC_PROG_SED])
@@ -51,6 +51,13 @@ AC_DEFUN([AX_COMPILER_FLAGS_CXXFLAGS],[
         ax_compiler_flags_test=""
     ])
 
+    # Check that -Wno-suggest-attribute=format is supported
+    AX_CHECK_COMPILE_FLAG([-Wno-suggest-attribute=format],[
+        ax_compiler_no_suggest_attribute_flags="-Wno-suggest-attribute=format"
+    ],[
+        ax_compiler_no_suggest_attribute_flags=""
+    ])
+
     # Base flags
     AX_APPEND_COMPILE_FLAGS([ dnl
         -fno-strict-aliasing dnl
@@ -104,7 +111,7 @@ AC_DEFUN([AX_COMPILER_FLAGS_CXXFLAGS],[
         AX_APPEND_FLAG([-Werror],ax_warn_cxxflags_variable)
 
         AX_APPEND_COMPILE_FLAGS([ dnl
-            -Wno-suggest-attribute=format dnl
+            [$ax_compiler_no_suggest_attribute_flags] dnl
         ],ax_warn_cxxflags_variable,[$ax_compiler_flags_test])
     ])
 
diff --git a/m4/ax_compiler_flags_gir.m4 b/m4/ax_compiler_flags_gir.m4
index 4a854f0..5b4924a 100644
--- a/m4/ax_compiler_flags_gir.m4
+++ b/m4/ax_compiler_flags_gir.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_gir.html
+#  https://www.gnu.org/software/autoconf-archive/ax_compiler_flags_gir.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -26,7 +26,7 @@
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 5
+#serial 6
 
 AC_DEFUN([AX_COMPILER_FLAGS_GIR],[
     AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
diff --git a/m4/ax_compiler_flags_ldflags.m4 b/m4/ax_compiler_flags_ldflags.m4
index fd7974e..976d119 100644
--- a/m4/ax_compiler_flags_ldflags.m4
+++ b/m4/ax_compiler_flags_ldflags.m4
@@ -1,6 +1,6 @@
-# =============================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_ldflags.html
-# =============================================================================
+# ==============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_compiler_flags_ldflags.html
+# ==============================================================================
 #
 # SYNOPSIS
 #
@@ -19,13 +19,14 @@
 # LICENSE
 #
 #   Copyright (c) 2014, 2015 Philip Withnall <philip@tecnocode.co.uk>
+#   Copyright (c) 2017, 2018 Reini Urban <rurban@cpan.org>
 #
 #   Copying and distribution of this file, with or without modification, are
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 7
+#serial 9
 
 AC_DEFUN([AX_COMPILER_FLAGS_LDFLAGS],[
     AX_REQUIRE_DEFINED([AX_APPEND_LINK_FLAGS])
@@ -48,7 +49,25 @@ AC_DEFUN([AX_COMPILER_FLAGS_LDFLAGS],[
         ax_compiler_flags_test=""
     ])
 
-    # macOS linker does not have --as-needed
+    AX_CHECK_LINK_FLAG([-Wl,--as-needed], [
+        AX_APPEND_LINK_FLAGS([-Wl,--as-needed],
+          [AM_LDFLAGS],[$ax_compiler_flags_test])
+    ])
+    AX_CHECK_LINK_FLAG([-Wl,-z,relro], [
+        AX_APPEND_LINK_FLAGS([-Wl,-z,relro],
+          [AM_LDFLAGS],[$ax_compiler_flags_test])
+    ])
+    AX_CHECK_LINK_FLAG([-Wl,-z,now], [
+        AX_APPEND_LINK_FLAGS([-Wl,-z,now],
+          [AM_LDFLAGS],[$ax_compiler_flags_test])
+    ])
+    AX_CHECK_LINK_FLAG([-Wl,-z,noexecstack], [
+        AX_APPEND_LINK_FLAGS([-Wl,-z,noexecstack],
+          [AM_LDFLAGS],[$ax_compiler_flags_test])
+    ])
+    # textonly, retpolineplt not yet
+
+    # macOS and cygwin linker do not have --as-needed
     AX_CHECK_LINK_FLAG([-Wl,--no-as-needed], [
         ax_compiler_flags_as_needed_option="-Wl,--no-as-needed"
     ], [
diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4
index b61fcb6..9e9eaed 100644
--- a/m4/ax_cxx_compile_stdcxx.m4
+++ b/m4/ax_cxx_compile_stdcxx.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -33,19 +33,18 @@
 #   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
 #   Copyright (c) 2015 Paul Norman <penorman@mac.com>
 #   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
-#   Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com>
+#   Copyright (c) 2016, 2018 Krzesimir Nowak <qdlacz@gmail.com>
 #
 #   Copying and distribution of this file, with or without modification, are
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 6
+#serial 10
 
 dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
 dnl  (serial version number 13).
 
-AX_REQUIRE_DEFINED([AC_MSG_WARN])
 AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
   m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"],
         [$1], [14], [ax_cxx_compile_alternatives="14 1y"],
@@ -61,14 +60,6 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
         [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])])
   AC_LANG_PUSH([C++])dnl
   ac_success=no
-  AC_CACHE_CHECK(whether $CXX supports C++$1 features by default,
-  ax_cv_cxx_compile_cxx$1,
-  [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
-    [ax_cv_cxx_compile_cxx$1=yes],
-    [ax_cv_cxx_compile_cxx$1=no])])
-  if test x$ax_cv_cxx_compile_cxx$1 = xyes; then
-    ac_success=yes
-  fi
 
   m4_if([$2], [noext], [], [dnl
   if test x$ac_success = xno; then
@@ -139,7 +130,6 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
               [define if the compiler supports basic C++$1 syntax])
   fi
   AC_SUBST(HAVE_CXX$1)
-  m4_if([$1], [17], [AC_MSG_WARN([C++17 is not yet standardized, so the checks may change in incompatible ways anytime])])
 ])
 
 
@@ -587,20 +577,12 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
 
 #error "This is not a C++ compiler"
 
-#elif __cplusplus <= 201402L
+#elif __cplusplus < 201703L
 
 #error "This is not a C++17 compiler"
 
 #else
 
-#if defined(__clang__)
-  #define REALLY_CLANG
-#else
-  #if defined(__GNUC__)
-    #define REALLY_GCC
-  #endif
-#endif
-
 #include <initializer_list>
 #include <utility>
 #include <type_traits>
@@ -608,16 +590,12 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
 namespace cxx17
 {
 
-#if !defined(REALLY_CLANG)
   namespace test_constexpr_lambdas
   {
 
-    // TODO: test it with clang++ from git
-
     constexpr int foo = [](){return 42;}();
 
   }
-#endif // !defined(REALLY_CLANG)
 
   namespace test::nested_namespace::definitions
   {
@@ -852,12 +830,9 @@ namespace cxx17
 
   }
 
-#if !defined(REALLY_CLANG)
   namespace test_template_argument_deduction_for_class_templates
   {
 
-    // TODO: test it with clang++ from git
-
     template <typename T1, typename T2>
     struct pair
     {
@@ -876,7 +851,6 @@ namespace cxx17
     }
 
   }
-#endif // !defined(REALLY_CLANG)
 
   namespace test_non_type_auto_template_parameters
   {
@@ -890,12 +864,9 @@ namespace cxx17
 
   }
 
-#if !defined(REALLY_CLANG)
   namespace test_structured_bindings
   {
 
-    // TODO: test it with clang++ from git
-
     int arr[2] = { 1, 2 };
     std::pair<int, int> pr = { 1, 2 };
 
@@ -927,14 +898,10 @@ namespace cxx17
     const auto [ x3, y3 ] = f3();
 
   }
-#endif // !defined(REALLY_CLANG)
 
-#if !defined(REALLY_CLANG)
   namespace test_exception_spec_type_system
   {
 
-    // TODO: test it with clang++ from git
-
     struct Good {};
     struct Bad {};
 
@@ -952,7 +919,6 @@ namespace cxx17
     static_assert (std::is_same_v<Good, decltype(f(g1, g2))>);
 
   }
-#endif // !defined(REALLY_CLANG)
 
   namespace test_inline_variables
   {
@@ -977,6 +943,6 @@ namespace cxx17
 
 }  // namespace cxx17
 
-#endif  // __cplusplus <= 201402L
+#endif  // __cplusplus < 201703L
 
 ]])
diff --git a/m4/ax_cxx_compile_stdcxx_11.m4 b/m4/ax_cxx_compile_stdcxx_11.m4
index 0aadeaf..1733fd8 100644
--- a/m4/ax_cxx_compile_stdcxx_11.m4
+++ b/m4/ax_cxx_compile_stdcxx_11.m4
@@ -1,6 +1,6 @@
-# ============================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html
-# ============================================================================
+# =============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html
+# =============================================================================
 #
 # SYNOPSIS
 #
@@ -33,7 +33,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 17
+#serial 18
 
 AX_REQUIRE_DEFINED([AX_CXX_COMPILE_STDCXX])
 AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [AX_CXX_COMPILE_STDCXX([11], [$1], [$2])])
diff --git a/m4/ax_generate_changelog.m4 b/m4/ax_generate_changelog.m4
index 71c5fd1..e2f0c54 100644
--- a/m4/ax_generate_changelog.m4
+++ b/m4/ax_generate_changelog.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_generate_changelog.html
+#  https://www.gnu.org/software/autoconf-archive/ax_generate_changelog.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -52,7 +52,7 @@
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 2
+#serial 3
 
 AC_DEFUN([AX_GENERATE_CHANGELOG],[
 	# Find git, defaulting to the 'missing' script so the user gets a nice
diff --git a/m4/ax_is_release.m4 b/m4/ax_is_release.m4
index 0892e65..9097ddb 100644
--- a/m4/ax_is_release.m4
+++ b/m4/ax_is_release.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#       http://www.gnu.org/software/autoconf-archive/ax_is_release.html
+#      https://www.gnu.org/software/autoconf-archive/ax_is_release.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -44,7 +44,7 @@
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved.
 
-#serial 5
+#serial 7
 
 AC_DEFUN([AX_IS_RELEASE],[
     AC_BEFORE([AC_INIT],[$0])
@@ -52,7 +52,7 @@ AC_DEFUN([AX_IS_RELEASE],[
     m4_case([$1],
       [git-directory],[
         # $is_release = (.git directory does not exist)
-        AS_IF([test -d ${top_srcdir}/.git],[ax_is_release=no],[ax_is_release=yes])
+        AS_IF([test -d ${srcdir}/.git],[ax_is_release=no],[ax_is_release=yes])
       ],
       [minor-version],[
         # $is_release = ($minor_version is even)
diff --git a/m4/ax_require_defined.m4 b/m4/ax_require_defined.m4
index cae1111..17c3eab 100644
--- a/m4/ax_require_defined.m4
+++ b/m4/ax_require_defined.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_require_defined.html
+#    https://www.gnu.org/software/autoconf-archive/ax_require_defined.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -30,7 +30,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 1
+#serial 2
 
 AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
   m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])