Remove compile warning
diff --git a/configure b/configure
index d9adcfb..10f8d83 100755
--- a/configure
+++ b/configure
@@ -2,7 +2,7 @@
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69 for ImageMagick 7.0.0-0.
 #
-# Report bugs to <http://www.imagemagick.org>.
+# Report bugs to <https://github.com/ImageMagick/ImageMagick/issues>.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -275,10 +275,10 @@
     $as_echo "$0: be upgraded to zsh 4.3.4 or later."
   else
     $as_echo "$0: Please tell bug-autoconf@gnu.org and
-$0: http://www.imagemagick.org about your system, including
-$0: any error possibly output before this message. Then
-$0: install a modern shell, or manually run the script
-$0: under such a shell if you do have one."
+$0: https://github.com/ImageMagick/ImageMagick/issues about
+$0: your system, including any error possibly output before
+$0: this message. Then install a modern shell, or manually
+$0: run the script under such a shell if you do have one."
   fi
   exit 1
 fi
@@ -592,8 +592,8 @@
 PACKAGE_TARNAME='ImageMagick'
 PACKAGE_VERSION='7.0.0-0'
 PACKAGE_STRING='ImageMagick 7.0.0-0'
-PACKAGE_BUGREPORT='http://www.imagemagick.org'
-PACKAGE_URL=''
+PACKAGE_BUGREPORT='https://github.com/ImageMagick/ImageMagick/issues'
+PACKAGE_URL='http://www.imagemagick.org'
 
 ac_unique_file="MagickCore/MagickCore.h"
 # Factoring default headers for most tests.
@@ -971,6 +971,10 @@
 GDI32_LIBS
 HAVE_LD_VERSION_SCRIPT_FALSE
 HAVE_LD_VERSION_SCRIPT_TRUE
+WARN_SCANNERFLAGS
+WARN_LDFLAGS
+WARN_CXXFLAGS
+WARN_CFLAGS
 PKG_CONFIG_LIBDIR
 PKG_CONFIG_PATH
 PKG_CONFIG
@@ -1147,6 +1151,8 @@
 with_gnu_ld
 with_dmalloc
 with_gcc_arch
+enable_compile_warnings
+enable_Werror
 enable_ld_version_script
 enable_bounds_checking
 enable_osx_universal_binary
@@ -1910,6 +1916,9 @@
                           do not reject slow dependency extractors
   --disable-dependency-tracking
                           speeds up one-time build
+  --enable-compile-warnings=[no/yes/error]
+                          Enable compiler warnings and errors
+  --disable-Werror        Unconditionally make all compiler warnings non-fatal
   --enable-ld-version-script
                           enable linker version script (default is enabled
                           when possible)
@@ -2099,7 +2108,8 @@
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
 
-Report bugs to <http://www.imagemagick.org>.
+Report bugs to <https://github.com/ImageMagick/ImageMagick/issues>.
+ImageMagick home page: <http://www.imagemagick.org>.
 _ACEOF
 ac_status=$?
 fi
@@ -2321,9 +2331,9 @@
 $as_echo "$as_me: WARNING: $2:     section \"Present But Cannot Be Compiled\"" >&2;}
     { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: proceeding with the compiler's result" >&5
 $as_echo "$as_me: WARNING: $2: proceeding with the compiler's result" >&2;}
-( $as_echo "## ----------------------------------------- ##
-## Report this to http://www.imagemagick.org ##
-## ----------------------------------------- ##"
+( $as_echo "## ---------------------------------------------------------------- ##
+## Report this to https://github.com/ImageMagick/ImageMagick/issues ##
+## ---------------------------------------------------------------- ##"
      ) | sed "s/^/$as_me: WARNING:     /" >&2
     ;;
 esac
@@ -3189,9 +3199,9 @@
 $as_echo "$as_me: WARNING: $2:     section \"Present But Cannot Be Compiled\"" >&2;}
     { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: $2: proceeding with the compiler's result" >&5
 $as_echo "$as_me: WARNING: $2: proceeding with the compiler's result" >&2;}
-( $as_echo "## ----------------------------------------- ##
-## Report this to http://www.imagemagick.org ##
-## ----------------------------------------- ##"
+( $as_echo "## ---------------------------------------------------------------- ##
+## Report this to https://github.com/ImageMagick/ImageMagick/issues ##
+## ---------------------------------------------------------------- ##"
      ) | sed "s/^/$as_me: WARNING:     /" >&2
     ;;
 esac
@@ -4241,125 +4251,9 @@
 
 
 # We'll loop over all known methods to create a tar archive until one works.
-_am_tools='gnutar plaintar pax cpio none'
+_am_tools='gnutar  pax cpio none'
 
-# The POSIX 1988 'ustar' format is defined with fixed-size fields.
-      # There is notably a 21 bits limit for the UID and the GID.  In fact,
-      # the 'pax' utility can hang on bigger UID/GID (see automake bug#8343
-      # and bug#13588).
-      am_max_uid=2097151 # 2^21 - 1
-      am_max_gid=$am_max_uid
-      # The $UID and $GID variables are not portable, so we need to resort
-      # to the POSIX-mandated id(1) utility.  Errors in the 'id' calls
-      # below are definitely unexpected, so allow the users to see them
-      # (that is, avoid stderr redirection).
-      am_uid=`id -u || echo unknown`
-      am_gid=`id -g || echo unknown`
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether UID '$am_uid' is supported by ustar format" >&5
-$as_echo_n "checking whether UID '$am_uid' is supported by ustar format... " >&6; }
-      if test $am_uid -le $am_max_uid; 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; }
-         _am_tools=none
-      fi
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether GID '$am_gid' is supported by ustar format" >&5
-$as_echo_n "checking whether GID '$am_gid' is supported by ustar format... " >&6; }
-      if test $am_gid -le $am_max_gid; 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; }
-        _am_tools=none
-      fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking how to create a ustar tar archive" >&5
-$as_echo_n "checking how to create a ustar tar archive... " >&6; }
-
-  # Go ahead even if we have the value already cached.  We do so because we
-  # need to set the values for the 'am__tar' and 'am__untar' variables.
-  _am_tools=${am_cv_prog_tar_ustar-$_am_tools}
-
-  for _am_tool in $_am_tools; do
-    case $_am_tool in
-    gnutar)
-      for _am_tar in tar gnutar gtar; do
-        { echo "$as_me:$LINENO: $_am_tar --version" >&5
-   ($_am_tar --version) >&5 2>&5
-   ac_status=$?
-   echo "$as_me:$LINENO: \$? = $ac_status" >&5
-   (exit $ac_status); } && break
-      done
-      am__tar="$_am_tar --format=ustar -chf - "'"$$tardir"'
-      am__tar_="$_am_tar --format=ustar -chf - "'"$tardir"'
-      am__untar="$_am_tar -xf -"
-      ;;
-    plaintar)
-      # Must skip GNU tar: if it does not support --format= it doesn't create
-      # ustar tarball either.
-      (tar --version) >/dev/null 2>&1 && continue
-      am__tar='tar chf - "$$tardir"'
-      am__tar_='tar chf - "$tardir"'
-      am__untar='tar xf -'
-      ;;
-    pax)
-      am__tar='pax -L -x ustar -w "$$tardir"'
-      am__tar_='pax -L -x ustar -w "$tardir"'
-      am__untar='pax -r'
-      ;;
-    cpio)
-      am__tar='find "$$tardir" -print | cpio -o -H ustar -L'
-      am__tar_='find "$tardir" -print | cpio -o -H ustar -L'
-      am__untar='cpio -i -H ustar -d'
-      ;;
-    none)
-      am__tar=false
-      am__tar_=false
-      am__untar=false
-      ;;
-    esac
-
-    # If the value was cached, stop now.  We just wanted to have am__tar
-    # and am__untar set.
-    test -n "${am_cv_prog_tar_ustar}" && break
-
-    # tar/untar a dummy directory, and stop if the command works.
-    rm -rf conftest.dir
-    mkdir conftest.dir
-    echo GrepMe > conftest.dir/file
-    { echo "$as_me:$LINENO: tardir=conftest.dir && eval $am__tar_ >conftest.tar" >&5
-   (tardir=conftest.dir && eval $am__tar_ >conftest.tar) >&5 2>&5
-   ac_status=$?
-   echo "$as_me:$LINENO: \$? = $ac_status" >&5
-   (exit $ac_status); }
-    rm -rf conftest.dir
-    if test -s conftest.tar; then
-      { echo "$as_me:$LINENO: $am__untar <conftest.tar" >&5
-   ($am__untar <conftest.tar) >&5 2>&5
-   ac_status=$?
-   echo "$as_me:$LINENO: \$? = $ac_status" >&5
-   (exit $ac_status); }
-      { echo "$as_me:$LINENO: cat conftest.dir/file" >&5
-   (cat conftest.dir/file) >&5 2>&5
-   ac_status=$?
-   echo "$as_me:$LINENO: \$? = $ac_status" >&5
-   (exit $ac_status); }
-      grep GrepMe conftest.dir/file >/dev/null 2>&1 && break
-    fi
-  done
-  rm -rf conftest.dir
-
-  if ${am_cv_prog_tar_ustar+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  am_cv_prog_tar_ustar=$_am_tool
-fi
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $am_cv_prog_tar_ustar" >&5
-$as_echo "$am_cv_prog_tar_ustar" >&6; }
+am__tar='$${TAR-tar} chof - "$$tardir"' am__untar='$${TAR-tar} xf -'
 
 
 
@@ -4513,7 +4407,7 @@
 
 MAGICK_VERSION=7.0.0-0
 
-MAGICK_GIT_REVISION=17653:80353a3:20160209
+MAGICK_GIT_REVISION=17656:f4f5483:20160209
 
 
 # Substitute library versioning
@@ -9307,7 +9201,7 @@
 
 fi
 if test -n "$PKG_CONFIG"; then
-	_pkg_min_version=0.9.0
+	_pkg_min_version=0.20
 	{ $as_echo "$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
@@ -9415,6 +9309,1356 @@
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_c_compiler_vendor" >&5
 $as_echo "$ax_cv_c_compiler_vendor" >&6; }
 
+
+
+    # C support is enabled by default.
+
+
+    # Only enable C++ support if AC_PROG_CXX is called. The redefinition of
+    # AC_PROG_CXX is so that a fatal error is emitted if this macro is called
+    # before AC_PROG_CXX, which would otherwise cause no C++ warnings to be
+    # checked.
+
+
+
+
+
+    # Default value for IS-RELEASE is $ax_is_release
+    ax_compiler_flags_is_release=$ax_is_release
+
+    # Check whether --enable-compile-warnings was given.
+if test "${enable_compile_warnings+set}" = set; then :
+  enableval=$enable_compile_warnings;
+else
+  if test "$ax_compiler_flags_is_release" = "yes"; then :
+  enable_compile_warnings="yes"
+else
+  enable_compile_warnings="error"
+fi
+fi
+
+    # Check whether --enable-Werror was given.
+if test "${enable_Werror+set}" = set; then :
+  enableval=$enable_Werror;
+else
+  enable_Werror=maybe
+fi
+
+
+    # Return the user's chosen warning level
+    if test "$enable_Werror" = "no" -a \
+                "$enable_compile_warnings" = "error"; then :
+
+        enable_compile_warnings="yes"
+
+fi
+
+    ax_enable_compile_warnings=$enable_compile_warnings
+
+
+
+
+
+
+
+
+
+
+    # Variable names
+
+
+    ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+    # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
+    # flags, otherwise they are always appended to the warn_cflags variable, and
+    # Clang warns on them for every compilation unit.
+    # If this is passed to GCC, it will explode, so the flag must be enabled
+    # conditionally.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -Werror=unknown-warning-option" >&5
+$as_echo_n "checking whether C compiler accepts -Werror=unknown-warning-option... " >&6; }
+if ${ax_cv_check_cflags___Werror_unknown_warning_option+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS  -Werror=unknown-warning-option"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ax_cv_check_cflags___Werror_unknown_warning_option=yes
+else
+  ax_cv_check_cflags___Werror_unknown_warning_option=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_check_cflags___Werror_unknown_warning_option" >&5
+$as_echo "$ax_cv_check_cflags___Werror_unknown_warning_option" >&6; }
+if test "x$ax_cv_check_cflags___Werror_unknown_warning_option" = xyes; then :
+
+        ax_compiler_flags_test="-Werror=unknown-warning-option"
+
+else
+
+        ax_compiler_flags_test=""
+
+fi
+
+
+    # Base flags
+
+
+
+
+for flag in          -fno-strict-aliasing              ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts $flag" >&5
+$as_echo_n "checking whether C compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CFLAGS+:} false; then :
+
+  case " $WARN_CFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS already contains \$flag"; } >&5
+  (: WARN_CFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+    if test "$ax_enable_compile_warnings" != "no"; then :
+
+        # "yes" flags
+
+
+
+
+for flag in              -Wall             -Wextra             -Wundef             -Wnested-externs             -Wwrite-strings             -Wpointer-arith             -Wmissing-declarations             -Wmissing-prototypes             -Wstrict-prototypes             -Wredundant-decls             -Wno-unused-parameter             -Wno-missing-field-initializers             -Wdeclaration-after-statement             -Wformat=2             -Wold-style-definition             -Wcast-align             -Wformat-nonliteral             -Wformat-security             -Wsign-compare             -Wstrict-aliasing             -Wshadow             -Winline             -Wpacked             -Wmissing-format-attribute             -Wmissing-noreturn             -Winit-self             -Wredundant-decls             -Wmissing-include-dirs             -Wunused-but-set-variable             -Warray-bounds             -Wimplicit-function-declaration             -Wreturn-type             -Wswitch-enum             -Wswitch-default                                                                ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts $flag" >&5
+$as_echo_n "checking whether C compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CFLAGS+:} false; then :
+
+  case " $WARN_CFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS already contains \$flag"; } >&5
+  (: WARN_CFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+fi
+    if test "$ax_enable_compile_warnings" = "error"; then :
+
+        # "error" flags; -Werror has to be appended unconditionally because
+        # it's not possible to test for
+        #
+        # suggest-attribute=format is disabled because it gives too many false
+        # positives
+
+if ${WARN_CFLAGS+:} false; then :
+
+  case " $WARN_CFLAGS " in #(
+  *" -Werror "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS already contains -Werror"; } >&5
+  (: WARN_CFLAGS already contains -Werror) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CFLAGS " -Werror"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CFLAGS=-Werror
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+
+
+
+
+
+for flag in              -Wno-suggest-attribute=format         ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts $flag" >&5
+$as_echo_n "checking whether C compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CFLAGS+:} false; then :
+
+  case " $WARN_CFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS already contains \$flag"; } >&5
+  (: WARN_CFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+fi
+
+    # In the flags below, when disabling specific flags, always add *both*
+    # -Wno-foo and -Wno-error=foo. This fixes the situation where (for example)
+    # we enable -Werror, disable a flag, and a build bot passes CFLAGS=-Wall,
+    # which effectively turns that flag back on again as an error.
+    for flag in $WARN_CFLAGS; do
+        case $flag in #(
+  -Wno-*=*) :
+     ;; #(
+  -Wno-*) :
+
+
+
+
+
+for flag in -Wno-error=$($as_echo $flag | $SED 's/^-Wno-//'); do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts $flag" >&5
+$as_echo_n "checking whether C compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CFLAGS+:} false; then :
+
+  case " $WARN_CFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS already contains \$flag"; } >&5
+  (: WARN_CFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CFLAGS=\"\$WARN_CFLAGS\""; } >&5
+  (: WARN_CFLAGS="$WARN_CFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+                 ;; #(
+  *) :
+     ;;
+esac
+    done
+
+    ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+    # Substitute the variables
+
+
+
+
+
+
+
+
+
+
+
+    # Variable names
+
+
+    ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+
+
+    # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
+    # flags, otherwise they are always appended to the warn_cxxflags variable,
+    # and Clang warns on them for every compilation unit.
+    # If this is passed to GCC, it will explode, so the flag must be enabled
+    # conditionally.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C++ compiler accepts -Werror=unknown-warning-option" >&5
+$as_echo_n "checking whether C++ compiler accepts -Werror=unknown-warning-option... " >&6; }
+if ${ax_cv_check_cxxflags___Werror_unknown_warning_option+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CXXFLAGS
+  CXXFLAGS="$CXXFLAGS  -Werror=unknown-warning-option"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  ax_cv_check_cxxflags___Werror_unknown_warning_option=yes
+else
+  ax_cv_check_cxxflags___Werror_unknown_warning_option=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CXXFLAGS=$ax_check_save_flags
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_check_cxxflags___Werror_unknown_warning_option" >&5
+$as_echo "$ax_cv_check_cxxflags___Werror_unknown_warning_option" >&6; }
+if test "x$ax_cv_check_cxxflags___Werror_unknown_warning_option" = xyes; then :
+
+        ax_compiler_flags_test="-Werror=unknown-warning-option"
+
+else
+
+        ax_compiler_flags_test=""
+
+fi
+
+
+    # Base flags
+
+
+
+
+for flag in          -fno-strict-aliasing              ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cxxflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C++ compiler accepts $flag" >&5
+$as_echo_n "checking whether C++ compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CXXFLAGS
+  CXXFLAGS="$CXXFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CXXFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CXXFLAGS+:} false; then :
+
+  case " $WARN_CXXFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS already contains \$flag"; } >&5
+  (: WARN_CXXFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CXXFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CXXFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+    if test "$ax_enable_compile_warnings" != "no"; then :
+
+        # "yes" flags
+
+
+
+
+for flag in              -Wall             -Wextra             -Wundef             -Wwrite-strings             -Wpointer-arith             -Wmissing-declarations             -Wredundant-decls             -Wno-unused-parameter             -Wno-missing-field-initializers             -Wformat=2             -Wcast-align             -Wformat-nonliteral             -Wformat-security             -Wsign-compare             -Wstrict-aliasing             -Wshadow             -Winline             -Wpacked             -Wmissing-format-attribute             -Wmissing-noreturn             -Winit-self             -Wredundant-decls             -Wmissing-include-dirs             -Wunused-but-set-variable             -Warray-bounds             -Wreturn-type             -Wno-overloaded-virtual             -Wswitch-enum             -Wswitch-default                                                                ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cxxflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C++ compiler accepts $flag" >&5
+$as_echo_n "checking whether C++ compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CXXFLAGS
+  CXXFLAGS="$CXXFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CXXFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CXXFLAGS+:} false; then :
+
+  case " $WARN_CXXFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS already contains \$flag"; } >&5
+  (: WARN_CXXFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CXXFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CXXFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+fi
+    if test "$ax_enable_compile_warnings" = "error"; then :
+
+        # "error" flags; -Werror has to be appended unconditionally because
+        # it's not possible to test for
+        #
+        # suggest-attribute=format is disabled because it gives too many false
+        # positives
+
+if ${WARN_CXXFLAGS+:} false; then :
+
+  case " $WARN_CXXFLAGS " in #(
+  *" -Werror "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS already contains -Werror"; } >&5
+  (: WARN_CXXFLAGS already contains -Werror) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CXXFLAGS " -Werror"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CXXFLAGS=-Werror
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+
+
+
+
+
+for flag in              -Wno-suggest-attribute=format         ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cxxflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C++ compiler accepts $flag" >&5
+$as_echo_n "checking whether C++ compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CXXFLAGS
+  CXXFLAGS="$CXXFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CXXFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CXXFLAGS+:} false; then :
+
+  case " $WARN_CXXFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS already contains \$flag"; } >&5
+  (: WARN_CXXFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CXXFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CXXFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+fi
+
+    # In the flags below, when disabling specific flags, always add *both*
+    # -Wno-foo and -Wno-error=foo. This fixes the situation where (for example)
+    # we enable -Werror, disable a flag, and a build bot passes CXXFLAGS=-Wall,
+    # which effectively turns that flag back on again as an error.
+    for flag in $WARN_CXXFLAGS; do
+        case $flag in #(
+  -Wno-*=*) :
+     ;; #(
+  -Wno-*) :
+
+
+
+
+
+for flag in -Wno-error=$($as_echo $flag | $SED 's/^-Wno-//'); do
+  as_CACHEVAR=`$as_echo "ax_cv_check_cxxflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C++ compiler accepts $flag" >&5
+$as_echo_n "checking whether C++ compiler accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CXXFLAGS
+  CXXFLAGS="$CXXFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CXXFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_CXXFLAGS+:} false; then :
+
+  case " $WARN_CXXFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS already contains \$flag"; } >&5
+  (: WARN_CXXFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_CXXFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_CXXFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_CXXFLAGS=\"\$WARN_CXXFLAGS\""; } >&5
+  (: WARN_CXXFLAGS="$WARN_CXXFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+                 ;; #(
+  *) :
+     ;;
+esac
+    done
+
+    ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+    # Substitute the variables
+
+
+
+
+
+
+
+
+
+
+    # Variable names
+
+
+    # Always pass -Werror=unknown-warning-option to get Clang to fail on bad
+    # flags, otherwise they are always appended to the warn_ldflags variable,
+    # and Clang warns on them for every compilation unit.
+    # If this is passed to GCC, it will explode, so the flag must be enabled
+    # conditionally.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -Werror=unknown-warning-option" >&5
+$as_echo_n "checking whether C compiler accepts -Werror=unknown-warning-option... " >&6; }
+if ${ax_cv_check_cflags___Werror_unknown_warning_option+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS  -Werror=unknown-warning-option"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ax_cv_check_cflags___Werror_unknown_warning_option=yes
+else
+  ax_cv_check_cflags___Werror_unknown_warning_option=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_check_cflags___Werror_unknown_warning_option" >&5
+$as_echo "$ax_cv_check_cflags___Werror_unknown_warning_option" >&6; }
+if test "x$ax_cv_check_cflags___Werror_unknown_warning_option" = xyes; then :
+
+        ax_compiler_flags_test="-Werror=unknown-warning-option"
+
+else
+
+        ax_compiler_flags_test=""
+
+fi
+
+
+    # Base flags
+
+
+
+
+for flag in          -Wl,--no-as-needed              ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_ldflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the linker accepts $flag" >&5
+$as_echo_n "checking whether the linker accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  LDFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_LDFLAGS+:} false; then :
+
+  case " $WARN_LDFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS already contains \$flag"; } >&5
+  (: WARN_LDFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_LDFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS=\"\$WARN_LDFLAGS\""; } >&5
+  (: WARN_LDFLAGS="$WARN_LDFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_LDFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS=\"\$WARN_LDFLAGS\""; } >&5
+  (: WARN_LDFLAGS="$WARN_LDFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+    if test "$ax_enable_compile_warnings" != "no"; then :
+
+        # "yes" flags
+
+
+
+
+for flag in       ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_ldflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the linker accepts $flag" >&5
+$as_echo_n "checking whether the linker accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  LDFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_LDFLAGS+:} false; then :
+
+  case " $WARN_LDFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS already contains \$flag"; } >&5
+  (: WARN_LDFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_LDFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS=\"\$WARN_LDFLAGS\""; } >&5
+  (: WARN_LDFLAGS="$WARN_LDFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_LDFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS=\"\$WARN_LDFLAGS\""; } >&5
+  (: WARN_LDFLAGS="$WARN_LDFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+fi
+    if test "$ax_enable_compile_warnings" = "error"; then :
+
+        # "error" flags; -Werror has to be appended unconditionally because
+        # it's not possible to test for
+        #
+        # suggest-attribute=format is disabled because it gives too many false
+        # positives
+
+
+
+
+for flag in              -Wl,--fatal-warnings         ; do
+  as_CACHEVAR=`$as_echo "ax_cv_check_ldflags_$ax_compiler_flags_test_$flag" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the linker accepts $flag" >&5
+$as_echo_n "checking whether the linker accepts $flag... " >&6; }
+if eval \${$as_CACHEVAR+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $ax_compiler_flags_test $flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  eval "$as_CACHEVAR=yes"
+else
+  eval "$as_CACHEVAR=no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  LDFLAGS=$ax_check_save_flags
+fi
+eval ac_res=\$$as_CACHEVAR
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_CACHEVAR"\" = x"yes"; then :
+
+if ${WARN_LDFLAGS+:} false; then :
+
+  case " $WARN_LDFLAGS " in #(
+  *" $flag "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS already contains \$flag"; } >&5
+  (: WARN_LDFLAGS already contains $flag) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_LDFLAGS " $flag"
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS=\"\$WARN_LDFLAGS\""; } >&5
+  (: WARN_LDFLAGS="$WARN_LDFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_LDFLAGS=$flag
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_LDFLAGS=\"\$WARN_LDFLAGS\""; } >&5
+  (: WARN_LDFLAGS="$WARN_LDFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+else
+  :
+fi
+
+done
+
+
+fi
+
+    # Substitute the variables
+
+
+
+
+
+
+    # Variable names
+
+
+    # Base flags
+
+if ${WARN_SCANNERFLAGS+:} false; then :
+
+  case " $WARN_SCANNERFLAGS " in #(
+  *"  "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS already contains "; } >&5
+  (: WARN_SCANNERFLAGS already contains ) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_SCANNERFLAGS " "
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS=\"\$WARN_SCANNERFLAGS\""; } >&5
+  (: WARN_SCANNERFLAGS="$WARN_SCANNERFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_SCANNERFLAGS=
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS=\"\$WARN_SCANNERFLAGS\""; } >&5
+  (: WARN_SCANNERFLAGS="$WARN_SCANNERFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+
+    if test "$ax_enable_compile_warnings" != "no"; then :
+
+        # "yes" flags
+
+if ${WARN_SCANNERFLAGS+:} false; then :
+
+  case " $WARN_SCANNERFLAGS " in #(
+  *"              --warn-all                                                              "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS already contains              --warn-all                                                             "; } >&5
+  (: WARN_SCANNERFLAGS already contains              --warn-all                                                             ) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_SCANNERFLAGS "              --warn-all                                                             "
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS=\"\$WARN_SCANNERFLAGS\""; } >&5
+  (: WARN_SCANNERFLAGS="$WARN_SCANNERFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_SCANNERFLAGS=             --warn-all
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS=\"\$WARN_SCANNERFLAGS\""; } >&5
+  (: WARN_SCANNERFLAGS="$WARN_SCANNERFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+
+fi
+    if test "$ax_enable_compile_warnings" = "error"; then :
+
+        # "error" flags
+
+if ${WARN_SCANNERFLAGS+:} false; then :
+
+  case " $WARN_SCANNERFLAGS " in #(
+  *"              --warn-error          "*) :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS already contains              --warn-error         "; } >&5
+  (: WARN_SCANNERFLAGS already contains              --warn-error         ) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } ;; #(
+  *) :
+
+     as_fn_append WARN_SCANNERFLAGS "              --warn-error         "
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS=\"\$WARN_SCANNERFLAGS\""; } >&5
+  (: WARN_SCANNERFLAGS="$WARN_SCANNERFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+     ;;
+esac
+
+else
+
+  WARN_SCANNERFLAGS=             --warn-error
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: : WARN_SCANNERFLAGS=\"\$WARN_SCANNERFLAGS\""; } >&5
+  (: WARN_SCANNERFLAGS="$WARN_SCANNERFLAGS") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+
+fi
+
+
+fi
+
+    # Substitute the variables
+
+
+
 # The AX_CFLAGS_WARN_ALL macro doesn't currently work for sunpro
 # compiler.
 if test "$ax_cv_c_compiler_vendor" != "sun"; then
@@ -14393,7 +15637,6 @@
 
 
 
-
 func_stripname_cnf ()
 {
   case $2 in
@@ -37306,7 +38549,8 @@
 Configuration commands:
 $config_commands
 
-Report bugs to <http://www.imagemagick.org>."
+Report bugs to <https://github.com/ImageMagick/ImageMagick/issues>.
+ImageMagick home page: <http://www.imagemagick.org>."
 
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1