diff -r 008fc72fd94d configure
--- a/configure	Wed Mar 18 21:53:15 2015 +0200
+++ b/configure	Wed Mar 18 22:36:00 2015 +0200
@@ -650,9 +650,6 @@ USE_SIGNAL_MODULE
 TCLTK_LIBS
 TCLTK_INCLUDES
 LIBFFI_INCLUDEDIR
-PKG_CONFIG_LIBDIR
-PKG_CONFIG_PATH
-PKG_CONFIG
 SHLIBS
 CFLAGSFORSHARED
 LINKFORSHARED
@@ -832,10 +829,7 @@ CFLAGS
 LDFLAGS
 LIBS
 CPPFLAGS
-CPP
-PKG_CONFIG
-PKG_CONFIG_PATH
-PKG_CONFIG_LIBDIR'
+CPP'
 
 
 # Initialize some variables set by options.
@@ -1523,11 +1517,6 @@ Some influential environment variables:
   CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
   CPP         C preprocessor
-  PKG_CONFIG  path to pkg-config utility
-  PKG_CONFIG_PATH
-              directories to add to pkg-config's search path
-  PKG_CONFIG_LIBDIR
-              path overriding pkg-config's built-in search path
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -6373,6 +6362,92 @@ UNIVERSAL_ARCH_FLAGS=
 # tweak BASECFLAGS based on compiler and platform
 case $GCC in
 yes)
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -Wall" >&5
+$as_echo_n "checking for -Wall... " >&6; }
+     ac_save_cc="$CC"
+     CC="$CC -Wall -Werror"
+     save_CFLAGS="$CFLAGS"
+     if ${ac_cv_all_warnings+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+           ac_cv_all_warnings=yes
+
+else
+
+           ac_cv_all_warnings=no
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_all_warnings" >&5
+$as_echo "$ac_cv_all_warnings" >&6; }
+
+    if test $ac_cv_all_warnings = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wall"
+    fi
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -Wextra" >&5
+$as_echo_n "checking for -Wextra... " >&6; }
+     ac_save_cc="$CC"
+     CC="$CC -Wextra -Werror"
+     save_CFLAGS="$CFLAGS"
+     if ${ac_cv_extra_warnings+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+           ac_cv_extra_warnings=yes
+
+else
+
+           ac_cv_extra_warnings=no
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_extra_warnings" >&5
+$as_echo "$ac_cv_extra_warnings" >&6; }
+
+    if test $ac_cv_extra_warnings = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wextra"
+    fi
+
     # Python doesn't violate C99 aliasing rules, but older versions of
     # GCC produce warnings for legal Python code.  Enable
     # -fno-strict-aliasing on versions of GCC that support but produce
@@ -6484,6 +6559,93 @@ fi
     if test $ac_cv_disable_unused_result_warning = yes
     then
       BASECFLAGS="$BASECFLAGS -Wno-unused-result"
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wno-unused-result"
+    fi
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking if we can turn off $CC unused parameter warning" >&5
+$as_echo_n "checking if we can turn off $CC unused parameter warning... " >&6; }
+     ac_save_cc="$CC"
+     CC="$CC -Wunused-parameter -Werror"
+     save_CFLAGS="$CFLAGS"
+     if ${ac_cv_disable_unused_parameter_warning+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+           ac_cv_disable_unused_parameter_warning=yes
+
+else
+
+           ac_cv_disable_unused_parameter_warning=no
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_disable_unused_parameter_warning" >&5
+$as_echo "$ac_cv_disable_unused_parameter_warning" >&6; }
+
+    if test $ac_cv_disable_unused_parameter_warning = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wno-unused-parameter"
+    fi
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking if we can turn off $CC missing field initializers warning" >&5
+$as_echo_n "checking if we can turn off $CC missing field initializers warning... " >&6; }
+     ac_save_cc="$CC"
+     CC="$CC -Wmissing-field-initializers -Werror"
+     save_CFLAGS="$CFLAGS"
+     if ${ac_cv_disable_missing_field_initializers+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+           ac_cv_disable_missing_field_initializers=yes
+
+else
+
+           ac_cv_disable_missing_field_initializers=no
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_disable_missing_field_initializers" >&5
+$as_echo "$ac_cv_disable_missing_field_initializers" >&6; }
+
+    if test $ac_cv_disable_missing_field_initializers = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wno-missing-field-initializers"
     fi
 
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -Werror=declaration-after-statement" >&5
@@ -9434,126 +9596,7 @@ else
 fi
 
 
-
-
-
-
-
-
-
-if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
-	if test -n "$ac_tool_prefix"; then
-  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
-set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_path_PKG_CONFIG+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  case $PKG_CONFIG in
-  [\\/]* | ?:[\\/]*)
-  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
-  ;;
-  *)
-  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-  ;;
-esac
-fi
-PKG_CONFIG=$ac_cv_path_PKG_CONFIG
-if test -n "$PKG_CONFIG"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PKG_CONFIG" >&5
-$as_echo "$PKG_CONFIG" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-fi
-if test -z "$ac_cv_path_PKG_CONFIG"; then
-  ac_pt_PKG_CONFIG=$PKG_CONFIG
-  # Extract the first word of "pkg-config", so it can be a program name with args.
-set dummy pkg-config; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_path_ac_pt_PKG_CONFIG+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  case $ac_pt_PKG_CONFIG in
-  [\\/]* | ?:[\\/]*)
-  ac_cv_path_ac_pt_PKG_CONFIG="$ac_pt_PKG_CONFIG" # Let the user override the test with a path.
-  ;;
-  *)
-  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_path_ac_pt_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-  ;;
-esac
-fi
-ac_pt_PKG_CONFIG=$ac_cv_path_ac_pt_PKG_CONFIG
-if test -n "$ac_pt_PKG_CONFIG"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_pt_PKG_CONFIG" >&5
-$as_echo "$ac_pt_PKG_CONFIG" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-  if test "x$ac_pt_PKG_CONFIG" = x; then
-    PKG_CONFIG=""
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
-$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
-ac_tool_warned=yes ;;
-esac
-    PKG_CONFIG=$ac_pt_PKG_CONFIG
-  fi
-else
-  PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
-fi
-
-fi
-if test -n "$PKG_CONFIG"; then
-	_pkg_min_version=0.9.0
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking pkg-config is at least version $_pkg_min_version" >&5
-$as_echo_n "checking pkg-config is at least version $_pkg_min_version... " >&6; }
-	if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-	else
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-		PKG_CONFIG=""
-	fi
-fi
+PKG_PROG_PKG_CONFIG
 
 # Check for use of the system expat library
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-system-expat" >&5
diff -r 008fc72fd94d configure.ac
--- a/configure.ac	Wed Mar 18 21:53:15 2015 +0200
+++ b/configure.ac	Wed Mar 18 22:36:00 2015 +0200
@@ -1163,6 +1163,50 @@ AC_SUBST(UNIVERSAL_ARCH_FLAGS)
 # tweak BASECFLAGS based on compiler and platform
 case $GCC in
 yes)
+    AC_MSG_CHECKING(for -Wall)
+     ac_save_cc="$CC"
+     CC="$CC -Wall -Werror"
+     save_CFLAGS="$CFLAGS"
+     AC_CACHE_VAL(ac_cv_all_warnings,
+       AC_COMPILE_IFELSE(
+         [
+           AC_LANG_PROGRAM([[]], [[]])
+         ],[
+           ac_cv_all_warnings=yes
+         ],[
+           ac_cv_all_warnings=no
+         ]))
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    AC_MSG_RESULT($ac_cv_all_warnings)
+
+    if test $ac_cv_all_warnings = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wall"
+    fi
+
+    AC_MSG_CHECKING(for -Wextra)
+     ac_save_cc="$CC"
+     CC="$CC -Wextra -Werror"
+     save_CFLAGS="$CFLAGS"
+     AC_CACHE_VAL(ac_cv_extra_warnings,
+       AC_COMPILE_IFELSE(
+         [
+           AC_LANG_PROGRAM([[]], [[]])
+         ],[
+           ac_cv_extra_warnings=yes
+         ],[
+           ac_cv_extra_warnings=no
+         ]))
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    AC_MSG_RESULT($ac_cv_extra_warnings)
+
+    if test $ac_cv_extra_warnings = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wextra"
+    fi
+
     # Python doesn't violate C99 aliasing rules, but older versions of
     # GCC produce warnings for legal Python code.  Enable
     # -fno-strict-aliasing on versions of GCC that support but produce
@@ -1218,6 +1262,51 @@ yes)
     if test $ac_cv_disable_unused_result_warning = yes
     then
       BASECFLAGS="$BASECFLAGS -Wno-unused-result"
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wno-unused-result"
+    fi
+
+    AC_MSG_CHECKING(if we can turn off $CC unused parameter warning)
+     ac_save_cc="$CC"
+     CC="$CC -Wunused-parameter -Werror"
+     save_CFLAGS="$CFLAGS"
+     AC_CACHE_VAL(ac_cv_disable_unused_parameter_warning,
+       AC_COMPILE_IFELSE(
+         [
+           AC_LANG_PROGRAM([[]], [[]])
+         ],[
+           ac_cv_disable_unused_parameter_warning=yes
+         ],[
+           ac_cv_disable_unused_parameter_warning=no
+         ]))
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    AC_MSG_RESULT($ac_cv_disable_unused_parameter_warning)
+
+    if test $ac_cv_disable_unused_parameter_warning = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wno-unused-parameter"
+    fi
+
+    AC_MSG_CHECKING(if we can turn off $CC missing field initializers warning)
+     ac_save_cc="$CC"
+     CC="$CC -Wmissing-field-initializers -Werror"
+     save_CFLAGS="$CFLAGS"
+     AC_CACHE_VAL(ac_cv_disable_missing_field_initializers,
+       AC_COMPILE_IFELSE(
+         [
+           AC_LANG_PROGRAM([[]], [[]])
+         ],[
+           ac_cv_disable_missing_field_initializers=yes
+         ],[
+           ac_cv_disable_missing_field_initializers=no
+         ]))
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    AC_MSG_RESULT($ac_cv_disable_missing_field_initializers)
+
+    if test $ac_cv_disable_missing_field_initializers = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wno-missing-field-initializers"
     fi
 
     AC_MSG_CHECKING(for -Werror=declaration-after-statement)