Merge branch '3.6.x'

1 files changed, 426 insertions, 0 deletions

diff --git a/m4/nx-macros.m4 b/m4/nx-macros.m4
new file mode 100644
index 000000000..b40f628b0
--- /dev/null
+++ b/m4/nx-macros.m4
@@ -0,0 +1,426 @@
+dnl nx-macros.m4.  Generated from xorg-macros.m4.in xorgversion.m4 by configure.
+dnl
+dnl Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
+dnl Copyright (c) 2017, Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
+dnl
+dnl Permission is hereby granted, free of charge, to any person obtaining a
+dnl copy of this software and associated documentation files (the "Software"),
+dnl to deal in the Software without restriction, including without limitation
+dnl the rights to use, copy, modify, merge, publish, distribute, sublicense,
+dnl and/or sell copies of the Software, and to permit persons to whom the
+dnl Software is furnished to do so, subject to the following conditions:
+dnl
+dnl The above copyright notice and this permission notice (including the next
+dnl paragraph) shall be included in all copies or substantial portions of the
+dnl Software.
+dnl
+dnl THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+dnl IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+dnl FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+dnl THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+dnl LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+dnl FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+dnl DEALINGS IN THE SOFTWARE.
+
+# NX_COMPILER_BRAND
+# -------------------
+# Checks for various brands of compilers and sets flags as appropriate:
+#   GNU gcc - relies on AC_PROG_CC (via AC_PROG_CC_C99) to set GCC to "yes"
+#   GNU g++ - relies on AC_PROG_CXX to set GXX to "yes"
+#   clang compiler - sets CLANGCC to "yes"
+#   Intel compiler - sets INTELCC to "yes"
+#   Sun/Oracle Solaris Studio cc - sets SUNCC to "yes"
+#
+# Derived from https://cgit.freedesktop.org/xorg/util/macros/ and adapted to
+# nxcomp{,shad}.
+
+AC_DEFUN([NX_COMPILER_BRAND], [
+AC_LANG_CASE(
+	[C], [
+		AC_REQUIRE([AC_PROG_CC_C99])
+	],
+	[C++], [
+		AC_REQUIRE([AC_PROG_CXX])
+	]
+)
+AC_CHECK_DECL([__clang__], [CLANGCC="yes"], [CLANGCC="no"])
+AC_CHECK_DECL([__INTEL_COMPILER], [INTELCC="yes"], [INTELCC="no"])
+AC_CHECK_DECL([__SUNPRO_C], [SUNCC="yes"], [SUNCC="no"])
+]) # NX_COMPILER_BRAND
+
+# NX_TESTSET_CFLAG(<variable>, <flag>, [<alternative flag>, ...])
+# ---------------
+# Test if the compiler works when passed the given flag as a command line argument.
+# If it succeeds, the flag is appeneded to the given variable.  If not, it tries the
+# next flag in the list until there are no more options.
+#
+# Note that this does not guarantee that the compiler supports the flag as some
+# compilers will simply ignore arguments that they do not understand, but we do
+# attempt to weed out false positives by using -Werror=unknown-warning-option and
+# -Werror=unused-command-line-argument
+#
+# Derived from https://cgit.freedesktop.org/xorg/util/macros/ and adapted to
+# nxcomp{,shad}.
+
+AC_DEFUN([NX_TESTSET_CFLAG], [
+m4_if([$#], 0, [m4_fatal([NX_TESTSET_CFLAG was given with an unsupported number of arguments])])
+m4_if([$#], 1, [m4_fatal([NX_TESTSET_CFLAG was given with an unsupported number of arguments])])
+
+AC_LANG_COMPILER_REQUIRE
+
+AC_LANG_CASE(
+	[C], [
+		AC_REQUIRE([AC_PROG_CC_C99])
+		define([PREFIX], [C])
+		define([CACHE_PREFIX], [cc])
+		define([COMPILER], [$CC])
+	],
+	[C++], [
+		define([PREFIX], [CXX])
+		define([CACHE_PREFIX], [cxx])
+		define([COMPILER], [$CXX])
+	]
+)
+
+[nx_testset_save_]PREFIX[FLAGS]="$PREFIX[FLAGS]"
+
+if test "x$[nx_testset_]CACHE_PREFIX[_unknown_warning_option]" = "x" ; then
+	PREFIX[FLAGS]="$PREFIX[FLAGS] -Werror=unknown-warning-option"
+	AC_CACHE_CHECK([if ]COMPILER[ supports -Werror=unknown-warning-option],
+			[nx_cv_]CACHE_PREFIX[_flag_unknown_warning_option],
+			AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])],
+					  [nx_cv_]CACHE_PREFIX[_flag_unknown_warning_option=yes],
+					  [nx_cv_]CACHE_PREFIX[_flag_unknown_warning_option=no]))
+	[nx_testset_]CACHE_PREFIX[_unknown_warning_option]=$[nx_cv_]CACHE_PREFIX[_flag_unknown_warning_option]
+	PREFIX[FLAGS]="$[nx_testset_save_]PREFIX[FLAGS]"
+fi
+
+if test "x$[nx_testset_]CACHE_PREFIX[_unused_command_line_argument]" = "x" ; then
+	if test "x$[nx_testset_]CACHE_PREFIX[_unknown_warning_option]" = "xyes" ; then
+		PREFIX[FLAGS]="$PREFIX[FLAGS] -Werror=unknown-warning-option"
+	fi
+	PREFIX[FLAGS]="$PREFIX[FLAGS] -Werror=unused-command-line-argument"
+	AC_CACHE_CHECK([if ]COMPILER[ supports -Werror=unused-command-line-argument],
+			[nx_cv_]CACHE_PREFIX[_flag_unused_command_line_argument],
+			AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])],
+					  [nx_cv_]CACHE_PREFIX[_flag_unused_command_line_argument=yes],
+					  [nx_cv_]CACHE_PREFIX[_flag_unused_command_line_argument=no]))
+	[nx_testset_]CACHE_PREFIX[_unused_command_line_argument]=$[nx_cv_]CACHE_PREFIX[_flag_unused_command_line_argument]
+	PREFIX[FLAGS]="$[nx_testset_save_]PREFIX[FLAGS]"
+fi
+
+found="no"
+m4_foreach([flag], m4_cdr($@), [
+	if test $found = "no" ; then
+		if test "x$nx_testset_]CACHE_PREFIX[_unknown_warning_option" = "xyes" ; then
+			PREFIX[FLAGS]="$PREFIX[FLAGS] -Werror=unknown-warning-option"
+		fi
+
+		if test "x$nx_testset_]CACHE_PREFIX[_unused_command_line_argument" = "xyes" ; then
+			PREFIX[FLAGS]="$PREFIX[FLAGS] -Werror=unused-command-line-argument"
+		fi
+
+		PREFIX[FLAGS]="$PREFIX[FLAGS] ]flag["
+
+dnl Some hackery here since AC_CACHE_VAL can't handle a non-literal varname
+		AC_MSG_CHECKING([if ]COMPILER[ supports ]flag[])
+		cacheid=AS_TR_SH([nx_cv_]CACHE_PREFIX[_flag_]flag[])
+		AC_CACHE_VAL($cacheid,
+			     [AC_LINK_IFELSE([AC_LANG_PROGRAM([int i;])],
+					     [eval $cacheid=yes],
+					     [eval $cacheid=no])])
+
+		PREFIX[FLAGS]="$[nx_testset_save_]PREFIX[FLAGS]"
+
+		eval supported=\$$cacheid
+		AC_MSG_RESULT([$supported])
+		if test "$supported" = "yes" ; then
+			$1="$$1 ]flag["
+			found="yes"
+		fi
+	fi
+])
+]) # NX_TESTSET_CFLAG
+
+# NX_COMPILER_FLAGS
+# ---------------
+# Defines BASE_CFLAGS or BASE_CXXFLAGS to contain a set of command line
+# arguments supported by the selected compiler which do NOT alter the generated
+# code.  These arguments will cause the compiler to print various warnings
+# during compilation AND turn a conservative set of warnings into errors.
+#
+# The set of flags supported by BASE_CFLAGS and BASE_CXXFLAGS will grow in
+# future versions of util-macros as options are added to new compilers.
+#
+# Derived from https://cgit.freedesktop.org/xorg/util/macros/ and adapted to
+# nxcomp{,shad}.
+
+AC_DEFUN([NX_COMPILER_FLAGS], [
+AC_REQUIRE([NX_COMPILER_BRAND])
+
+AC_ARG_ENABLE(selective-werror,
+              AS_HELP_STRING([--disable-selective-werror],
+                             [Turn off selective compiler errors. (default: enabled)]),
+              [SELECTIVE_WERROR=$enableval],
+              [SELECTIVE_WERROR=yes])
+
+AC_LANG_CASE(
+        [C], [
+                define([PREFIX], [C])
+        ],
+        [C++], [
+                define([PREFIX], [CXX])
+        ]
+)
+# -v is too short to test reliably with NX_TESTSET_CFLAG
+if test "x$SUNCC" = "xyes"; then
+    [BASE_]PREFIX[FLAGS]="-v"
+else
+    [BASE_]PREFIX[FLAGS]=""
+fi
+
+# This chunk of warnings were those that existed in the legacy CWARNFLAGS
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wall])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wpointer-arith])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wmissing-declarations])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wformat=2], [-Wformat])
+
+AC_LANG_CASE(
+	[C], [
+		NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wstrict-prototypes])
+		NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wmissing-prototypes])
+		NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wnested-externs])
+		NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wbad-function-cast])
+		NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wold-style-definition], [-fd])
+		NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wdeclaration-after-statement])
+	]
+)
+
+# This chunk adds additional warnings that could catch undesired effects.
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wunused])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wuninitialized])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wshadow])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wmissing-noreturn])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wmissing-format-attribute])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wredundant-decls])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wlogical-op])
+
+# These are currently disabled because they are noisy.  They will be enabled
+# in the future once the codebase is sufficiently modernized to silence
+# them.  For now, I don't want them to drown out the other warnings.
+# NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wparentheses])
+# NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wcast-align])
+# NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wcast-qual])
+
+# Turn some warnings into errors, so we don't accidently get successful builds
+# when there are problems that should be fixed.
+
+if test "x$SELECTIVE_WERROR" = "xyes" ; then
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=implicit], [-errwarn=E_NO_EXPLICIT_TYPE_GIVEN -errwarn=E_NO_IMPLICIT_DECL_ALLOWED])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=nonnull])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=init-self])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=main])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=missing-braces])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=sequence-point])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=return-type], [-errwarn=E_FUNC_HAS_NO_RETURN_STMT])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=trigraphs])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=array-bounds])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=write-strings])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=address])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=int-to-pointer-cast], [-errwarn=E_BAD_PTR_INT_COMBINATION])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Werror=pointer-to-int-cast]) # Also -errwarn=E_BAD_PTR_INT_COMBINATION
+else
+AC_MSG_WARN([You have chosen not to turn some select compiler warnings into errors.  This should not be necessary.  Please report why you needed to do so in a bug report at $PACKAGE_BUGREPORT])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wimplicit])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wnonnull])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Winit-self])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wmain])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wmissing-braces])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wsequence-point])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wreturn-type])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wtrigraphs])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Warray-bounds])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wwrite-strings])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Waddress])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wint-to-pointer-cast])
+NX_TESTSET_CFLAG([[BASE_]PREFIX[FLAGS]], [-Wpointer-to-int-cast])
+fi
+
+AC_SUBST([BASE_]PREFIX[FLAGS])
+]) # NX_COMPILER_FLAGS
+
+# NX_STRICT_OPTION
+# -----------------------
+#
+# Add configure option to enable strict compilation flags, such as treating
+# warnings as fatal errors.
+# If --enable-strict-compilation is passed to configure, adds strict flags to
+# $BASE_CFLAGS or $BASE_CXXFLAGS.
+#
+# Also exports $STRICT_CFLAGS for use in other tests or when strict compilation
+# is unconditionally desired.
+AC_DEFUN([NX_STRICT_OPTION], [
+AC_REQUIRE([NX_COMPILER_FLAGS])
+
+AC_ARG_ENABLE(strict-compilation,
+                          AS_HELP_STRING([--enable-strict-compilation],
+                          [Enable all warnings from compiler and make them errors (default: disabled)]),
+                          [STRICT_COMPILE=$enableval], [STRICT_COMPILE=no])
+
+AC_LANG_CASE(
+        [C], [
+                define([PREFIX], [C])
+        ],
+        [C++], [
+                define([PREFIX], [CXX])
+        ]
+)
+
+[STRICT_]PREFIX[FLAGS]=""
+NX_TESTSET_CFLAG([[STRICT_]PREFIX[FLAGS]], [-pedantic])
+NX_TESTSET_CFLAG([[STRICT_]PREFIX[FLAGS]], [-Werror], [-errwarn])
+
+# Earlier versions of gcc (eg: 4.2) support -Werror=attributes, but do not
+# activate it with -Werror, so we add it here explicitly.
+NX_TESTSET_CFLAG([[STRICT_]PREFIX[FLAGS]], [-Werror=attributes])
+
+if test "x$STRICT_COMPILE" = "xyes"; then
+    [BASE_]PREFIX[FLAGS]="$[BASE_]PREFIX[FLAGS] $[STRICT_]PREFIX[FLAGS]"
+fi
+AC_SUBST([STRICT_]PREFIX[FLAGS])
+AC_SUBST([BASE_]PREFIX[FLAGS])
+]) # NX_STRICT_OPTION
+
+# NX_DEFAULT_OPTIONS
+# --------------------
+#
+# Defines default options for X.Org-like modules.
+#
+AC_DEFUN([NX_DEFAULT_OPTIONS], [
+AC_REQUIRE([AC_PROG_INSTALL])
+NX_COMPILER_FLAGS
+NX_STRICT_OPTION
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])],
+    [AC_SUBST([AM_DEFAULT_VERBOSITY], [1])])
+]) # NX_DEFAULT_OPTIONS
+
+# NX_CHECK_MALLOC_ZERO
+# ----------------------
+# Minimum version: 1.0.0
+#
+# Defines {MALLOC,XMALLOC,XTMALLOC}_ZERO_CFLAGS appropriately if
+# malloc(0) returns NULL.  Packages should add one of these cflags to
+# their AM_CFLAGS (or other appropriate *_CFLAGS) to use them.
+AC_DEFUN([NX_CHECK_MALLOC_ZERO],[
+AC_ARG_ENABLE(malloc0returnsnull,
+        AS_HELP_STRING([--enable-malloc0returnsnull],
+                       [malloc(0) returns NULL (default: auto)]),
+        [MALLOC_ZERO_RETURNS_NULL=$enableval],
+        [MALLOC_ZERO_RETURNS_NULL=auto])
+
+AC_MSG_CHECKING([whether malloc(0) returns NULL])
+if test "x$MALLOC_ZERO_RETURNS_NULL" = xauto; then
+        AC_RUN_IFELSE([AC_LANG_PROGRAM([
+#include <stdlib.h>
+],[
+    char *m0, *r0, *c0, *p;
+    m0 = malloc(0);
+    p = malloc(10);
+    r0 = realloc(p,0);
+    c0 = calloc(0,10);
+    exit((m0 == 0 || r0 == 0 || c0 == 0) ? 0 : 1);
+])],
+                [MALLOC_ZERO_RETURNS_NULL=yes],
+                [MALLOC_ZERO_RETURNS_NULL=no],
+                [MALLOC_ZERO_RETURNS_NULL=yes])
+fi
+AC_MSG_RESULT([$MALLOC_ZERO_RETURNS_NULL])
+
+if test "x$MALLOC_ZERO_RETURNS_NULL" = xyes; then
+        MALLOC_ZERO_CFLAGS="-DMALLOC_0_RETURNS_NULL"
+        XMALLOC_ZERO_CFLAGS=$MALLOC_ZERO_CFLAGS
+        XTMALLOC_ZERO_CFLAGS="$MALLOC_ZERO_CFLAGS -DXTMALLOC_BC"
+else
+        MALLOC_ZERO_CFLAGS=""
+        XMALLOC_ZERO_CFLAGS=""
+        XTMALLOC_ZERO_CFLAGS=""
+fi
+
+AC_SUBST([MALLOC_ZERO_CFLAGS])
+AC_SUBST([XMALLOC_ZERO_CFLAGS])
+AC_SUBST([XTMALLOC_ZERO_CFLAGS])
+]) # NX_CHECK_MALLOC_ZERO
+
+
+dnl Check to see if we're running under Cygwin32.
+
+AC_DEFUN([NX_BUILD_ON_CYGWIN32],
+[AC_CACHE_CHECK([for Cygwin32 environment], nxconf_cv_cygwin32,
+[AC_TRY_COMPILE(,[return __CYGWIN32__;],
+nxconf_cv_cygwin32=yes, nxconf_cv_cygwin32=no)
+rm -f conftest*])
+CYGWIN32=
+test "$nxconf_cv_cygwin32" = yes && CYGWIN32=yes
+]) # NX_BUILD_ON_CYGWIN32
+
+dnl Check whether we're building on a AMD64.
+
+AC_DEFUN([NX_BUILD_ON_AMD64],
+[AC_CACHE_CHECK([for Amd64 environment], nxconf_cv_amd64,
+[AC_TRY_COMPILE(,[return (__amd64__ || __x86_64__);],
+nxconf_cv_amd64=yes, nxconf_cv_amd64=no)
+rm -f conftest*])
+AMD64=
+test "$nxconf_cv_amd64" = yes && AMD64=yes
+]) # NX_BUILD_ON_AMD64
+
+dnl Check for Darwin environment.
+
+AC_DEFUN([NX_BUILD_ON_DARWIN],
+[AC_CACHE_CHECK([for Darwin environment], nxconf_cv_darwin,
+[AC_TRY_COMPILE(,[return __APPLE__;],
+nxconf_cv_darwin=yes, nxconf_cv_darwin=no)
+rm -f conftest*])
+DARWIN=
+test "$nxconf_cv_darwin" = yes && DARWIN=yes
+]) # NX_BUILD_ON_DARWIN
+
+# Check to see if we're running under Solaris.
+
+AC_DEFUN([NX_BUILD_ON_SUN],
+[AC_CACHE_CHECK([for Solaris environment], nxconf_cv_sun,
+[AC_TRY_COMPILE(,[return __sun;],
+nxconf_cv_sun=yes, nxconf_cv_sun=no)
+rm -f conftest*])
+SUN=
+test "$nxconf_cv_sun" = yes && SUN=yes
+]) # NX_BUILD_ON_SUN
+
+# Check to see if we're running under FreeBSD.
+
+AC_DEFUN([NX_BUILD_ON_FreeBSD],
+[AC_CACHE_CHECK([for FreeBSD environment], nxconf_cv_freebsd,
+[AC_TRY_COMPILE(,[return __FreeBSD__;],
+nxconf_cv_freebsd=yes, nxconf_cv_freebsd=no)
+rm -f conftest*])
+FreeBSD=
+test "$nxconf_cv_freebsd" = yes && FreeBSD=yes
+]) # NX_BUILD_ON_FreeBSD
+
+AC_DEFUN([LIBJPEG_FALLBACK_CHECK],[
+AC_MSG_CHECKING([for libjpeg shared libary file and headers])
+AC_CHECK_LIB([jpeg], [jpeg_destroy_compress],
+    [have_jpeg_lib=yes], [have_jpeg_lib=no])
+AC_CHECK_HEADERS([jpeglib.h],
+    [have_jpeg_headers=yes], [have_jpeg_headers=no])
+
+if test x"$have_jpeg_lib" = "xyes" && test x"$have_jpeg_headers" = "xyes"; then
+    AC_MSG_RESULT([yes])
+    JPEG_CFLAGS=""
+    JPEG_LIBS="-ljpeg"
+else
+    AC_MSG_RESULT([no])
+    AC_MSG_FAILURE([Could not find libjpeg on your system, make sure
+the JPEG shared library and header files are installed.])
+fi
+]) # LIBJPEG_FALLBACK_CHECK