diff --git a/configure.ac b/configure.ac
index 4b68a30f..d2c41f26 100644
--- a/configure.ac
+++ b/configure.ac
@@ -46,7 +46,7 @@ AC_CANONICAL_HOST
 # define target, target_cpu, target_vendor, target_os
 AC_CANONICAL_TARGET
 
-AM_INIT_AUTOMAKE([-Wall foreign std-options 1.9.6])
+AM_INIT_AUTOMAKE([-Wall -Wno-portability foreign std-options subdir-objects 1.9.6])
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 AM_MAINTAINER_MODE
 AC_CONFIG_SRCDIR([src/main.cxx])
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 57983238..4507414f 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -25,7 +25,7 @@ MOSTLYCLEANFILES = *.xml
 DISTCLEANFILES = $(ASCIIDOC_HTML)
 MAINTAINERCLEANFILES = $(ASCIIDOC_MAN_INST)
 
-A2X_ARGS = --format=manpage --destination-dir=$(builddir)/../doc
+A2X_ARGS = --format=manpage
 if HAVE_ASCIIDOC_NO_XMLLINT
     A2X_ARGS += --no-xmllint
 endif
@@ -49,8 +49,11 @@ endif
 
 # The rest of the Makefile is enabled only if we have asciidoc
 if HAVE_ASCIIDOC
-
-ASCIIDOC_ICONS_DIR ?= /usr/share/asciidoc/images/icons
+# Try to discover the correct iconsdir.  Use the first one that
+# contains an entry matching `tip.*'.
+ASCIIDOC_ICONS_DIRS := /etc/asciidoc/icons /etc/asciidoc/images /etc/asciidoc/images/icons /etc/asciidoc/images/../icons \
+                       /usr/share/asciidoc/icons /usr/share/asciidoc/images /usr/share/asciidoc/images/icons
+ASCIIDOC_ICONS_DIR ?= $(dir $(firstword $(strip $(foreach f,$(addsuffix /tip*,$(ASCIIDOC_ICONS_DIRS)),$(wildcard $(f))))))
 # Additional attributes are defined in guide.conf
 ASCIIDOC_ARGS = --unsafe -a toc -a data-uri -a badges -a icons -a iconsdir=$(ASCIIDOC_ICONS_DIR)
 
diff --git a/m4/intl/po.m4 b/m4/intl/po.m4
index 0734762a..f7c9c067 100644
--- a/m4/intl/po.m4
+++ b/m4/intl/po.m4
@@ -24,7 +24,7 @@ AC_DEFUN([AM_PO_SUBDIRS],
 [
   AC_REQUIRE([AC_PROG_MAKE_SET])dnl
   AC_REQUIRE([AC_PROG_INSTALL])dnl
-  AC_REQUIRE([AM_PROG_MKDIR_P])dnl defined by automake
+  AC_REQUIRE([AC_PROG_MKDIR_P])dnl
   AC_REQUIRE([AM_NLS])dnl
 
   dnl Release version of the gettext macros. This is used to ensure that
diff --git a/m4/tls.m4 b/m4/tls.m4
index 5d8a34f5..986bed42 100644
--- a/m4/tls.m4
+++ b/m4/tls.m4
@@ -3,7 +3,7 @@ AC_DEFUN([CHECK_TLS], [
   AC_MSG_CHECKING([for TLS support])
   AC_LANG_PUSH(C++)
 
-  AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
+  AC_RUN_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
                 [chktls_save_CXXFLAGS="$CXXFLAGS"
                  thread_CXXFLAGS=failed
                  for flag in "" "-pthread" "-lpthread"; do
@@ -44,7 +44,7 @@ AC_DEFUN([CHECK_TLS], [
                      CXXFLAGS="$chktls_save_CXXFLAGS"
                  fi],
                 [ac_cv_tls=no],
-                [AC_LINK_IFELSE([__thread int a; int b; int main() { return a = b; }],
+                [AC_LINK_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
 		                [ac_cv_tls=yes], [ac_cv_tls=no])]
   )