freebsd-dev/config/kernel.m4
Brian Behlendorf 12c1acde76 Set -Wno-unused-but-set-variable globally
As of gcc-4.6 the option -Wunused-but-set-variable is enabled by
default.  While this is a useful warning there are numerous places
in the ZFS code when a variable is set and then only checked in an
ASSERT().  To avoid having to update every instance of this in the
code we now set -Wno-unused-but-set-variable to suppress the warning.

Additionally, when building with --enable-debug and -Werror set these
warning also become fatal.  We can reevaluate the suppression of these
error at a later time if it becomes an issue.  For now we are basically
just reverting to the previous gcc behavior.
2011-04-19 10:44:10 -07:00

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dnl #
dnl # Default ZFS kernel configuration
dnl #
AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL
ZFS_AC_SPL
ZFS_AC_KERNEL_CONFIG
ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS
ZFS_AC_KERNEL_TYPE_FMODE_T
ZFS_AC_KERNEL_KOBJ_NAME_LEN
ZFS_AC_KERNEL_BLKDEV_GET_BY_PATH
ZFS_AC_KERNEL_OPEN_BDEV_EXCLUSIVE
ZFS_AC_KERNEL_INVALIDATE_BDEV_ARGS
ZFS_AC_KERNEL_BDEV_LOGICAL_BLOCK_SIZE
ZFS_AC_KERNEL_BIO_EMPTY_BARRIER
ZFS_AC_KERNEL_BIO_FAILFAST
ZFS_AC_KERNEL_BIO_FAILFAST_DTD
ZFS_AC_KERNEL_REQ_FAILFAST_MASK
ZFS_AC_KERNEL_BIO_END_IO_T_ARGS
ZFS_AC_KERNEL_BIO_RW_SYNC
ZFS_AC_KERNEL_BIO_RW_SYNCIO
ZFS_AC_KERNEL_REQ_SYNC
ZFS_AC_KERNEL_BLK_END_REQUEST
ZFS_AC_KERNEL_BLK_FETCH_REQUEST
ZFS_AC_KERNEL_BLK_REQUEUE_REQUEST
ZFS_AC_KERNEL_BLK_RQ_BYTES
ZFS_AC_KERNEL_BLK_RQ_POS
ZFS_AC_KERNEL_BLK_RQ_SECTORS
ZFS_AC_KERNEL_GET_DISK_RO
ZFS_AC_KERNEL_RQ_IS_SYNC
ZFS_AC_KERNEL_RQ_FOR_EACH_SEGMENT
ZFS_AC_KERNEL_CONST_XATTR_HANDLER
ZFS_AC_KERNEL_XATTR_HANDLER_GET
ZFS_AC_KERNEL_XATTR_HANDLER_SET
ZFS_AC_KERNEL_FSYNC_2ARGS
ZFS_AC_KERNEL_EVICT_INODE
ZFS_AC_KERNEL_INSERT_INODE_LOCKED
if test "$LINUX_OBJ" != "$LINUX"; then
KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"
fi
AC_SUBST(KERNELMAKE_PARAMS)
dnl # -Wall -fno-strict-aliasing -Wstrict-prototypes and other
dnl # compiler options are added by the kernel build system.
KERNELCPPFLAGS="$KERNELCPPFLAGS -Wno-unused-but-set-variable"
KERNELCPPFLAGS="$KERNELCPPFLAGS -DHAVE_SPL -D_KERNEL"
KERNELCPPFLAGS="$KERNELCPPFLAGS -DTEXT_DOMAIN=\\\"zfs-linux-kernel\\\""
AC_SUBST(KERNELCPPFLAGS)
])
dnl #
dnl # Detect name used for Module.symvers file in kernel
dnl #
AC_DEFUN([ZFS_AC_MODULE_SYMVERS], [
modpost=$LINUX/scripts/Makefile.modpost
AC_MSG_CHECKING([kernel file name for module symbols])
if test -f "$modpost"; then
if grep -q Modules.symvers $modpost; then
LINUX_SYMBOLS=Modules.symvers
else
LINUX_SYMBOLS=Module.symvers
fi
if ! test -f "$LINUX_OBJ/$LINUX_SYMBOLS"; then
AC_MSG_ERROR([
*** Please make sure the kernel devel package for your distribution
*** is installed. If your building with a custom kernel make sure the
*** kernel is configured, built, and the '--with-linux=PATH' configure
*** option refers to the location of the kernel source.])
fi
else
LINUX_SYMBOLS=NONE
fi
AC_MSG_RESULT($LINUX_SYMBOLS)
AC_SUBST(LINUX_SYMBOLS)
])
dnl #
dnl # Detect the kernel to be built against
dnl #
AC_DEFUN([ZFS_AC_KERNEL], [
AC_ARG_WITH([linux],
AS_HELP_STRING([--with-linux=PATH],
[Path to kernel source]),
[kernelsrc="$withval"])
AC_ARG_WITH(linux-obj,
AS_HELP_STRING([--with-linux-obj=PATH],
[Path to kernel build objects]),
[kernelbuild="$withval"])
AC_MSG_CHECKING([kernel source directory])
if test -z "$kernelsrc"; then
if test -e "/lib/modules/$(uname -r)/source"; then
headersdir="/lib/modules/$(uname -r)/source"
sourcelink=$(readlink -f "$headersdir")
elif test -e "/lib/modules/$(uname -r)/build"; then
headersdir="/lib/modules/$(uname -r)/build"
sourcelink=$(readlink -f "$headersdir")
else
sourcelink=$(ls -1d /usr/src/kernels/* \
/usr/src/linux-* \
2>/dev/null | grep -v obj | tail -1)
fi
if test -n "$sourcelink" && test -e ${sourcelink}; then
kernelsrc=`readlink -f ${sourcelink}`
else
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([
*** Please make sure the kernel devel package for your distribution
*** is installed then try again. If that fails you can specify the
*** location of the kernel source with the '--with-linux=PATH' option.])
fi
else
if test "$kernelsrc" = "NONE"; then
kernsrcver=NONE
fi
fi
AC_MSG_RESULT([$kernelsrc])
AC_MSG_CHECKING([kernel build directory])
if test -z "$kernelbuild"; then
if test -e "/lib/modules/$(uname -r)/build"; then
kernelbuild=`readlink -f /lib/modules/$(uname -r)/build`
elif test -d ${kernelsrc}-obj/${target_cpu}/${target_cpu}; then
kernelbuild=${kernelsrc}-obj/${target_cpu}/${target_cpu}
elif test -d ${kernelsrc}-obj/${target_cpu}/default; then
kernelbuild=${kernelsrc}-obj/${target_cpu}/default
elif test -d `dirname ${kernelsrc}`/build-${target_cpu}; then
kernelbuild=`dirname ${kernelsrc}`/build-${target_cpu}
else
kernelbuild=${kernelsrc}
fi
fi
AC_MSG_RESULT([$kernelbuild])
AC_MSG_CHECKING([kernel source version])
utsrelease1=$kernelbuild/include/linux/version.h
utsrelease2=$kernelbuild/include/linux/utsrelease.h
utsrelease3=$kernelbuild/include/generated/utsrelease.h
if test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1; then
utsrelease=linux/version.h
elif test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2; then
utsrelease=linux/utsrelease.h
elif test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3; then
utsrelease=generated/utsrelease.h
fi
if test "$utsrelease"; then
kernsrcver=`(echo "#include <$utsrelease>";
echo "kernsrcver=UTS_RELEASE") |
cpp -I $kernelbuild/include |
grep "^kernsrcver=" | cut -d \" -f 2`
if test -z "$kernsrcver"; then
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([*** Cannot determine kernel version.])
fi
else
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([*** Cannot find UTS_RELEASE definition.])
fi
AC_MSG_RESULT([$kernsrcver])
LINUX=${kernelsrc}
LINUX_OBJ=${kernelbuild}
LINUX_VERSION=${kernsrcver}
AC_SUBST(LINUX)
AC_SUBST(LINUX_OBJ)
AC_SUBST(LINUX_VERSION)
ZFS_AC_MODULE_SYMVERS
])
dnl #
dnl # Detect name used for the additional SPL Module.symvers file. If one
dnl # does not exist this is likely because the SPL has been configured
dnl # but not built. To allow recursive builds a good guess is made as to
dnl # what this file will be named based on what it is named in the kernel
dnl # build products. This file will first be used at link time so if
dnl # the guess is wrong the build will fail then. This unfortunately
dnl # means the ZFS package does not contain a reliable mechanism to
dnl # detect symbols exported by the SPL at configure time.
dnl #
AC_DEFUN([ZFS_AC_SPL_MODULE_SYMVERS], [
AC_MSG_CHECKING([spl file name for module symbols])
if test -r $SPL_OBJ/Module.symvers; then
SPL_SYMBOLS=Module.symvers
elif test -r $SPL_OBJ/Modules.symvers; then
SPL_SYMBOLS=Modules.symvers
elif test -r $SPL_OBJ/module/Module.symvers; then
SPL_SYMBOLS=Module.symvers
elif test -r $SPL_OBJ/module/Modules.symvers; then
SPL_SYMBOLS=Modules.symvers
else
SPL_SYMBOLS=$LINUX_SYMBOLS
fi
AC_MSG_RESULT([$SPL_SYMBOLS])
AC_SUBST(SPL_SYMBOLS)
])
dnl #
dnl # Detect the SPL module to be built against
dnl #
AC_DEFUN([ZFS_AC_SPL], [
AC_ARG_WITH([spl],
AS_HELP_STRING([--with-spl=PATH],
[Path to spl source]),
[splsrc="$withval"])
AC_ARG_WITH([spl-obj],
AS_HELP_STRING([--with-spl-obj=PATH],
[Path to spl build objects]),
[splbuild="$withval"])
AC_MSG_CHECKING([spl source directory])
if test -z "$splsrc"; then
sourcelink=`ls -1d /usr/src/spl-*/${LINUX_VERSION} \
2>/dev/null | tail -1`
if test -z "$sourcelink" || test ! -e $sourcelink; then
sourcelink=../spl
fi
if test -e $sourcelink; then
splsrc=`readlink -f ${sourcelink}`
else
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([
*** Please make sure the spl devel package for your distribution
*** is installed then try again. If that fails you can specify the
*** location of the spl source with the '--with-spl=PATH' option.])
fi
else
if test "$splsrc" = "NONE"; then
splbuild=NONE
splsrcver=NONE
fi
fi
AC_MSG_RESULT([$splsrc])
AC_MSG_CHECKING([spl build directory])
if test -z "$splbuild"; then
splbuild=${splsrc}
fi
AC_MSG_RESULT([$splbuild])
AC_MSG_CHECKING([spl source version])
if test -r $splbuild/spl_config.h &&
fgrep -q SPL_META_VERSION $splbuild/spl_config.h; then
splsrcver=`(echo "#include <spl_config.h>";
echo "splsrcver=SPL_META_VERSION") |
cpp -I $splbuild |
grep "^splsrcver=" | cut -d \" -f 2`
fi
if test -z "$splsrcver"; then
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([
*** Cannot determine the version of the spl source.
*** Please prepare the spl source before running this script])
fi
AC_MSG_RESULT([$splsrcver])
SPL=${splsrc}
SPL_OBJ=${splbuild}
SPL_VERSION=${splsrcver}
AC_SUBST(SPL)
AC_SUBST(SPL_OBJ)
AC_SUBST(SPL_VERSION)
ZFS_AC_SPL_MODULE_SYMVERS
])
dnl #
dnl # Certain kernel build options are not supported. These must be
dnl # detected at configure time and cause a build failure. Otherwise
dnl # modules may be successfully built that behave incorrectly.
dnl #
dnl # CONFIG_PREEMPT - Preempt kernels require special handling.
dnl #
dnl # There are certain kernel build options which when enabled are
dnl # completely incompatible with non GPL kernel modules. It is best
dnl # to detect these at configure time and fail with a clear error
dnl # rather than build everything and fail during linking.
dnl #
dnl # CONFIG_DEBUG_LOCK_ALLOC - Maps mutex_lock() to mutex_lock_nested()
dnl #
AC_DEFUN([ZFS_AC_KERNEL_CONFIG], [
ZFS_LINUX_CONFIG([PREEMPT],
AC_MSG_ERROR([
*** Kernel built with CONFIG_PREEMPT which is not supported.
** You must rebuild your kernel without this option.]), [])
if test "$ZFS_META_LICENSE" = CDDL; then
ZFS_LINUX_CONFIG([DEBUG_LOCK_ALLOC],
AC_MSG_ERROR([
*** Kernel built with CONFIG_DEBUG_LOCK_ALLOC which is
*** incompatible with the CDDL license. You must rebuild
*** your kernel without this option.]), [])
fi
if test "$ZFS_META_LICENSE" = GPL; then
AC_DEFINE([HAVE_GPL_ONLY_SYMBOLS], [1],
[Define to 1 if licensed under the GPL])
fi
])
dnl #
dnl # ZFS_LINUX_CONFTEST
dnl #
AC_DEFUN([ZFS_LINUX_CONFTEST], [
cat confdefs.h - <<_ACEOF >conftest.c
$1
_ACEOF
])
dnl #
dnl # ZFS_LANG_PROGRAM(C)([PROLOGUE], [BODY])
dnl #
m4_define([ZFS_LANG_PROGRAM], [
$1
int
main (void)
{
dnl Do *not* indent the following line: there may be CPP directives.
dnl Don't move the `;' right after for the same reason.
$2
;
return 0;
}
])
dnl #
dnl # ZFS_LINUX_COMPILE_IFELSE / like AC_COMPILE_IFELSE
dnl #
AC_DEFUN([ZFS_LINUX_COMPILE_IFELSE], [
m4_ifvaln([$1], [ZFS_LINUX_CONFTEST([$1])])
rm -Rf build && mkdir -p build
echo "obj-m := conftest.o" >build/Makefile
AS_IF(
[AC_TRY_COMMAND(cp conftest.c build && make [$2] -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
[$4],
[_AC_MSG_LOG_CONFTEST m4_ifvaln([$5],[$5])]
)
rm -Rf build
])
dnl #
dnl # ZFS_LINUX_TRY_COMPILE like AC_TRY_COMPILE
dnl #
AC_DEFUN([ZFS_LINUX_TRY_COMPILE],
[ZFS_LINUX_COMPILE_IFELSE(
[AC_LANG_SOURCE([ZFS_LANG_PROGRAM([[$1]], [[$2]])])],
[modules],
[test -s build/conftest.o],
[$3], [$4])
])
dnl #
dnl # ZFS_LINUX_CONFIG
dnl #
AC_DEFUN([ZFS_LINUX_CONFIG],
[AC_MSG_CHECKING([whether Linux was built with CONFIG_$1])
ZFS_LINUX_TRY_COMPILE([
#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
],[
#ifndef CONFIG_$1
#error CONFIG_$1 not #defined
#endif
],[
AC_MSG_RESULT([yes])
$2
],[
AC_MSG_RESULT([no])
$3
])
])
dnl #
dnl # ZFS_CHECK_SYMBOL_EXPORT
dnl # check symbol exported or not
dnl #
AC_DEFUN([ZFS_CHECK_SYMBOL_EXPORT],
[AC_MSG_CHECKING([whether symbol $1 is exported])
grep -q -E '[[[:space:]]]$1[[[:space:]]]' \
$LINUX_OBJ/$LINUX_SYMBOLS 2>/dev/null
rc=$?
if test $rc -ne 0; then
export=0
for file in $2; do
grep -q -E "EXPORT_SYMBOL.*($1)" "$LINUX/$file" 2>/dev/null
rc=$?
if test $rc -eq 0; then
export=1
break;
fi
done
if test $export -eq 0; then
AC_MSG_RESULT([no])
$4
else
AC_MSG_RESULT([yes])
$3
fi
else
AC_MSG_RESULT([yes])
$3
fi
])