diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4
index df5aff8c..764d44ab 100644
--- a/m4/ax_check_compile_flag.m4
+++ b/m4/ax_check_compile_flag.m4
@@ -19,6 +19,8 @@
 #   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
 #   force the compiler to issue an error when a bad flag is given.
 #
+#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
 #   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
 #   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
 #
@@ -38,7 +40,7 @@
 #   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/>.
+#   with this program. If not, see <https://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
@@ -53,7 +55,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 4
+#serial 5
 
 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_define.m4 b/m4/ax_check_define.m4
index 4bc69486..20ba8086 100644
--- a/m4/ax_check_define.m4
+++ b/m4/ax_check_define.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_check_define.html
+#     https://www.gnu.org/software/autoconf-archive/ax_check_define.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -29,7 +29,7 @@
 #   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/>.
+#   with this program. If not, see <https://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
@@ -44,7 +44,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 8
+#serial 9
 
 AU_ALIAS([AC_CHECK_DEFINED], [AC_CHECK_DEFINE])
 AC_DEFUN([AC_CHECK_DEFINE],[
diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
index 633be4ac..594d1ca0 100644
--- a/m4/ax_check_link_flag.m4
+++ b/m4/ax_check_link_flag.m4
@@ -1,10 +1,10 @@
 # ===========================================================================
-#    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
 #
-#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
 #
 # DESCRIPTION
 #
@@ -19,6 +19,8 @@
 #   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
 #   issue an error when a bad flag is given.
 #
+#   INPUT gives an alternative input source to AC_LINK_IFELSE.
+#
 #   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
 #   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
 #
@@ -38,7 +40,7 @@
 #   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/>.
+#   with this program. If not, see <https://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
@@ -53,7 +55,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 4
+#serial 5
 
 AC_DEFUN([AX_CHECK_LINK_FLAG],
 [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
diff --git a/m4/ax_pthread.m4 b/m4/ax_pthread.m4
index 4c4051ea..fff77db6 100644
--- a/m4/ax_pthread.m4
+++ b/m4/ax_pthread.m4
@@ -82,7 +82,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 23
+#serial 24
 
 AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
 AC_DEFUN([AX_PTHREAD], [
diff --git a/m4/ax_valgrind_check.m4 b/m4/ax_valgrind_check.m4
index faed023a..078fa910 100644
--- a/m4/ax_valgrind_check.m4
+++ b/m4/ax_valgrind_check.m4
@@ -1,22 +1,27 @@
 # ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_valgrind_check.html
+#    https://www.gnu.org/software/autoconf-archive/ax_valgrind_check.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
+#   AX_VALGRIND_DFLT(memcheck|helgrind|drd|sgcheck, on|off)
 #   AX_VALGRIND_CHECK()
 #
 # DESCRIPTION
 #
-#   Checks whether Valgrind is present and, if so, allows running `make
-#   check` under a variety of Valgrind tools to check for memory and
-#   threading errors.
+#   AX_VALGRIND_CHECK checks whether Valgrind is present and, if so, allows
+#   running `make check` under a variety of Valgrind tools to check for
+#   memory and threading errors.
 #
 #   Defines VALGRIND_CHECK_RULES which should be substituted in your
 #   Makefile; and $enable_valgrind which can be used in subsequent configure
 #   output. VALGRIND_ENABLED is defined and substituted, and corresponds to
 #   the value of the --enable-valgrind option, which defaults to being
-#   enabled if Valgrind is installed and disabled otherwise.
+#   enabled if Valgrind is installed and disabled otherwise. Individual
+#   Valgrind tools can be disabled via --disable-valgrind-<tool>, the
+#   default is configurable via the AX_VALGRIND_DFLT command or is to use
+#   all commands not disabled via AX_VALGRIND_DFLT. All AX_VALGRIND_DFLT
+#   calls must be made before the call to AX_VALGRIND_CHECK.
 #
 #   If unit tests are written using a shell script and automake's
 #   LOG_COMPILER system, the $(VALGRIND) variable can be used within the
@@ -28,6 +33,7 @@
 #
 #   configure.ac:
 #
+#     AX_VALGRIND_DFLT([sgcheck], [off])
 #     AX_VALGRIND_CHECK
 #
 #   Makefile.am:
@@ -40,9 +46,15 @@
 #   which includes "@VALGRIND_CHECK_RULES@" (assuming the module has been
 #   configured with --enable-valgrind). Running `make check-valgrind` in
 #   that directory will run the module's test suite (`make check`) once for
-#   each of the available Valgrind tools (out of memcheck, helgrind, drd and
-#   sgcheck), and will output results to test-suite-$toolname.log for each.
-#   The target will succeed if there are zero errors and fail otherwise.
+#   each of the available Valgrind tools (out of memcheck, helgrind and drd)
+#   while the sgcheck will be skipped unless enabled again on the
+#   commandline with --enable-valgrind-sgcheck. The results for each check
+#   will be output to test-suite-$toolname.log. The target will succeed if
+#   there are zero errors and fail otherwise.
+#
+#   Alternatively, a "check-valgrind-$TOOL" rule will be added, for $TOOL in
+#   memcheck, helgrind, drd and sgcheck. These are useful because often only
+#   some of those tools can be ran cleanly on a codebase.
 #
 #   The macro supports running with and without libtool.
 #
@@ -55,13 +67,23 @@
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 8
+#serial 15
+
+dnl Configured tools
+m4_define([valgrind_tool_list], [[memcheck], [helgrind], [drd], [sgcheck]])
+m4_set_add_all([valgrind_exp_tool_set], [sgcheck])
+m4_foreach([vgtool], [valgrind_tool_list],
+           [m4_define([en_dflt_valgrind_]vgtool, [on])])
+
+AC_DEFUN([AX_VALGRIND_DFLT],[
+	m4_define([en_dflt_valgrind_$1], [$2])
+])dnl
 
 AC_DEFUN([AX_VALGRIND_CHECK],[
 	dnl Check for --enable-valgrind
 	AC_ARG_ENABLE([valgrind],
 	              [AS_HELP_STRING([--enable-valgrind], [Whether to enable Valgrind on the unit tests (requires GNU make)])],
-	              [enable_valgrind=$enableval],[enable_valgrind=no])
+	              [enable_valgrind=$enableval],[enable_valgrind=])
 
 	AS_IF([test "$enable_valgrind" != "no"],[
 		# Check for Valgrind.
@@ -81,22 +103,45 @@ AC_DEFUN([AX_VALGRIND_CHECK],[
 	AC_SUBST([VALGRIND_ENABLED],[$enable_valgrind])
 
 	# Check for Valgrind tools we care about.
-	m4_define([valgrind_tool_list],[[memcheck], [helgrind], [drd], [exp-sgcheck]])
-
-	AS_IF([test "$VALGRIND" != ""],[
-		m4_foreach([vgtool],[valgrind_tool_list],[
-			m4_define([vgtooln],AS_TR_SH(vgtool))
-			m4_define([ax_cv_var],[ax_cv_valgrind_tool_]vgtooln)
-			AC_CACHE_CHECK([for Valgrind tool ]vgtool,ax_cv_var,[
-				ax_cv_var=
-				AS_IF([`$VALGRIND --tool=vgtool --help >/dev/null 2>&1`],[
-					ax_cv_var="vgtool"
+	[valgrind_enabled_tools=]
+	m4_foreach([vgtool],[valgrind_tool_list],[
+		AC_ARG_ENABLE([valgrind-]vgtool,
+		    m4_if(m4_defn([en_dflt_valgrind_]vgtool),[off],dnl
+[AS_HELP_STRING([--enable-valgrind-]vgtool, [Whether to use ]vgtool[ during the Valgrind tests])],dnl
+[AS_HELP_STRING([--disable-valgrind-]vgtool, [Whether to skip ]vgtool[ during the Valgrind tests])]),
+		              [enable_valgrind_]vgtool[=$enableval],
+		              [enable_valgrind_]vgtool[=])
+		AS_IF([test "$enable_valgrind" = "no"],[
+			enable_valgrind_]vgtool[=no],
+		      [test "$enable_valgrind_]vgtool[" ]dnl
+m4_if(m4_defn([en_dflt_valgrind_]vgtool), [off], [= "yes"], [!= "no"]),[
+			AC_CACHE_CHECK([for Valgrind tool ]vgtool,
+			               [ax_cv_valgrind_tool_]vgtool,[
+				ax_cv_valgrind_tool_]vgtool[=no
+				m4_set_contains([valgrind_exp_tool_set],vgtool,
+				    [m4_define([vgtoolx],[exp-]vgtool)],
+				    [m4_define([vgtoolx],vgtool)])
+				AS_IF([`$VALGRIND --tool=]vgtoolx[ --help >/dev/null 2>&1`],[
+					ax_cv_valgrind_tool_]vgtool[=yes
 				])
 			])
-
-			AC_SUBST([VALGRIND_HAVE_TOOL_]vgtooln,[$ax_cv_var])
+			AS_IF([test "$ax_cv_valgrind_tool_]vgtool[" = "no"],[
+				AS_IF([test "$enable_valgrind_]vgtool[" = "yes"],[
+					AC_MSG_ERROR([Valgrind does not support ]vgtool[; reconfigure with --disable-valgrind-]vgtool)
+				],[
+					enable_valgrind_]vgtool[=no
+				])
+			],[
+				enable_valgrind_]vgtool[=yes
+			])
 		])
+		AS_IF([test "$enable_valgrind_]vgtool[" = "yes"],[
+			valgrind_enabled_tools="$valgrind_enabled_tools ]m4_bpatsubst(vgtool,[^exp-])["
+		])
+		AC_SUBST([ENABLE_VALGRIND_]vgtool,[$enable_valgrind_]vgtool)
 	])
+	AC_SUBST([valgrind_tools],["]m4_join([ ], valgrind_tool_list)["])
+	AC_SUBST([valgrind_enabled_tools],[$valgrind_enabled_tools])
 
 [VALGRIND_CHECK_RULES='
 # Valgrind check
@@ -118,7 +163,6 @@ VALGRIND_drd_FLAGS ?=
 VALGRIND_sgcheck_FLAGS ?=
 
 # Internal use
-valgrind_tools = memcheck helgrind drd sgcheck
 valgrind_log_files = $(addprefix test-suite-,$(addsuffix .log,$(valgrind_tools)))
 
 valgrind_memcheck_flags = --tool=memcheck $(VALGRIND_memcheck_FLAGS)
@@ -129,6 +173,9 @@ valgrind_sgcheck_flags = --tool=exp-sgcheck $(VALGRIND_sgcheck_FLAGS)
 valgrind_quiet = $(valgrind_quiet_$(V))
 valgrind_quiet_ = $(valgrind_quiet_$(AM_DEFAULT_VERBOSITY))
 valgrind_quiet_0 = --quiet
+valgrind_v_use   = $(valgrind_v_use_$(V))
+valgrind_v_use_  = $(valgrind_v_use_$(AM_DEFAULT_VERBOSITY))
+valgrind_v_use_0 = @echo "  USE   " $(patsubst check-valgrind-%,%,$''@):;
 
 # Support running with and without libtool.
 ifneq ($(LIBTOOL),)
@@ -140,13 +187,10 @@ endif
 # Use recursive makes in order to ignore errors during check
 check-valgrind:
 ifeq ($(VALGRIND_ENABLED),yes)
-	-$(foreach tool,$(valgrind_tools), \
-		$(if $(VALGRIND_HAVE_TOOL_$(tool))$(VALGRIND_HAVE_TOOL_exp_$(tool)), \
-			$(MAKE) $(AM_MAKEFLAGS) -k check-valgrind-tool VALGRIND_TOOL=$(tool); \
-		) \
-	)
+	$(A''M_V_at)$(MAKE) $(AM_MAKEFLAGS) -k \
+		$(foreach tool, $(valgrind_enabled_tools), check-valgrind-$(tool))
 else
-	@echo "Need to reconfigure with --enable-valgrind"
+	@echo "Need to use GNU make and reconfigure with --enable-valgrind"
 endif
 
 # Valgrind running
@@ -160,16 +204,22 @@ VALGRIND_LOG_COMPILER = \
 	$(valgrind_lt) \
 	$(VALGRIND) $(VALGRIND_SUPPRESSIONS) --error-exitcode=1 $(VALGRIND_FLAGS)
 
-check-valgrind-tool:
-ifeq ($(VALGRIND_ENABLED),yes)
-	$(MAKE) check-TESTS \
-		TESTS_ENVIRONMENT="$(VALGRIND_TESTS_ENVIRONMENT)" \
-		LOG_COMPILER="$(VALGRIND_LOG_COMPILER)" \
-		LOG_FLAGS="$(valgrind_$(VALGRIND_TOOL)_flags)" \
-		TEST_SUITE_LOG=test-suite-$(VALGRIND_TOOL).log
+define valgrind_tool_rule =
+check-valgrind-$(1):
+ifeq ($$(VALGRIND_ENABLED)-$$(ENABLE_VALGRIND_$(1)),yes-yes)
+	$$(valgrind_v_use)$$(MAKE) check-TESTS \
+		TESTS_ENVIRONMENT="$$(VALGRIND_TESTS_ENVIRONMENT)" \
+		LOG_COMPILER="$$(VALGRIND_LOG_COMPILER)" \
+		LOG_FLAGS="$$(valgrind_$(1)_flags)" \
+		TEST_SUITE_LOG=test-suite-$(1).log
+else ifeq ($$(VALGRIND_ENABLED),yes)
+	@echo "Need to reconfigure with --enable-valgrind-$(1)"
 else
 	@echo "Need to reconfigure with --enable-valgrind"
 endif
+endef
+
+$(foreach tool,$(valgrind_tools),$(eval $(call valgrind_tool_rule,$(tool))))
 
 A''M_DISTCHECK_CONFIGURE_FLAGS ?=
 A''M_DISTCHECK_CONFIGURE_FLAGS += --disable-valgrind
@@ -177,14 +227,9 @@ A''M_DISTCHECK_CONFIGURE_FLAGS += --disable-valgrind
 MOSTLYCLEANFILES ?=
 MOSTLYCLEANFILES += $(valgrind_log_files)
 
-.PHONY: check-valgrind check-valgrind-tool
+.PHONY: check-valgrind $(add-prefix check-valgrind-,$(valgrind_tools))
 ']
 
-	AS_IF([test "$enable_valgrind" != "yes"],[
-VALGRIND_CHECK_RULES='
-check-valgrind:
-	@echo "Need to use GNU make and reconfigure with --enable-valgrind"'
-])
 	AC_SUBST([VALGRIND_CHECK_RULES])
 	m4_ifdef([_AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE([VALGRIND_CHECK_RULES])])
 ])