Some changes for separate Linux source and build trees.

Add LINUX_SRC_DIR variable to point to Linux source tree (LINUX_DIR points
to the Linux build tree).  It can be set with a new --with-linuxsrcdir
option or determined automatically from the build tree.
Changed some configure tests to check the Linux source tree instead of the
build tree.  The affected tests are COMEDI_CHECK_PCMCIA_PROBE,
COMEDI_CHECK_LINUX_KBUILD and COMEDI_CHECK_HAVE_MUTEX_H.  The
COMEDI_CHECK_LINUX_KBUILD test has been simplified because it no longer
has to check for separate source and build trees.

diff --git a/configure.ac b/configure.ac
index e62d5f15f3d228b245b245349b455a19d9334517..c39e62c4e1ba3fde50d9213cb93b146888823d7a 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -67,7 +67,7 @@ CC=$LINUX_CC
  -DKBUILD_BASENAME=\$(shell basename \$< .c)"]
 AC_SUBST(COMEDI_CFLAGS)
 
-COMEDI_CHECK_PCMCIA_PROBE([$LINUX_DIR], [ENABLE_PCMCIA="yes"], [ENABLE_PCMCIA="no"])
+COMEDI_CHECK_PCMCIA_PROBE([$LINUX_SRC_DIR], [ENABLE_PCMCIA="yes"], [ENABLE_PCMCIA="no"])
 #disable pcmcia by default until someone updates it to current kernel api
 ENABLE_PCMCIA="no"
 AC_ARG_ENABLE([pcmcia],[  --disable-pcmcia     Disable support for PCMCIA devices],
@@ -86,11 +86,11 @@ else
        AC_MSG_NOTICE([USB support disabled])
        AM_CONDITIONAL(CONFIG_USB,false)
 fi
-COMEDI_CHECK_LINUX_KBUILD([$LINUX_DIR], [ENABLE_KBUILD="yes"], [ENABLE_KBUILD="no"])
+COMEDI_CHECK_LINUX_KBUILD([$LINUX_SRC_DIR], [ENABLE_KBUILD="yes"], [ENABLE_KBUILD="no"])
 AC_ARG_ENABLE([kbuild], [  --enable-kbuild     Force use (or not) of kernel's Kbuild system to build modules (needs recent 2.6 kernel)],
        [ENABLE_KBUILD=$enableval], [])
 AM_CONDITIONAL([CONFIG_KBUILD], [test ${ENABLE_KBUILD} = "yes"])
-COMEDI_CHECK_HAVE_MUTEX_H([$LINUX_DIR], [HAVE_MUTEX_H="yes"], [HAVE_MUTEX_H="no"])
+COMEDI_CHECK_HAVE_MUTEX_H([$LINUX_SRC_DIR], [HAVE_MUTEX_H="yes"], [HAVE_MUTEX_H="no"])
 AS_LINUX_CONFIG_OPTION_MODULE(CONFIG_ISA)
 AS_LINUX_CONFIG_OPTION_MODULE(CONFIG_PCI)
 

diff --git a/m4/as-linux.m4 b/m4/as-linux.m4
index bad202624b4e9b47224f3568307d6ddaa6c7d7fe..86902ec8bc20af68cca0ad0d86e833f8357a7769 100644 (file)
--- a/m4/as-linux.m4
+++ b/m4/as-linux.m4
@@ -13,6 +13,7 @@ dnl AS_LINUX()
 dnl
 dnl this macro adds the options
 dnl --with-linuxdir        to specify a kernel build tree location
+dnl --with-linuxsrcdir     to specify a kernel source tree location
 dnl --with-linuxconfig     to specify a kernel .config file
 dnl --with-kernel-release  to specify an alternative uname -r
 dnl --with-machine         to specify an alternative uname -m
@@ -23,7 +24,9 @@ dnl --with-modulesdeveldir to specify the base install location of build stuff
 
 dnl this macro defines:
 dnl LINUX_DIR
-dnl   The directory where the Linux source resides.
+dnl   The directory where the Linux build tree resides.
+dnl LINUX_SRC_DIR
+dnl   The directory where the Linux source tree resides.
 dnl CONFIG_FILE
 dnl   The Linux config file
 dnl LINUX_ARCH
@@ -54,9 +57,9 @@ dnl LINUX_MODULE_EXT
 dnl   Module extension (.o or .ko)
 dnl LINUX_MODPOST
 dnl   path to modpost script
-dnl modulesdir
+dnl MODULESDIR
 dnl   base install path for kernel modules
-dnl modulesdeveldir
+dnl MODULESDEVELDIR
 dnl   base install path for kernel module development files
 dnl
 dnl End of search list.
@@ -73,8 +76,10 @@ AC_DEFUN([AS_LINUX],
        dnl override the LINUX_MACHINE value if he did
        AS_LINUX_RPM_TARGET()
 
-       dnl find the kernel source tree for the given uname -r
+       dnl find the kernel build tree for the given uname -r
        AS_LINUX_DIR()
+       dnl find the kernel source tree from the build tree or --with-linuxsrcdir
+       AS_LINUX_SRC_DIR($LINUX_DIR)
        dnl check if user supplied an EXTRAVERSION, and if not get from uname -r
        AS_LINUX_EXTRAVERSION($LINUX_KERNEL_RELEASE)
        dnl check if user supplied a config file; if not, guess a good one
@@ -106,18 +111,18 @@ AC_DEFUN([AS_LINUX],
 ])
 
 
-dnl check if we can find a source dir for the Linux kernel
-dnl defines LINUX_DIR to the absolute location of a usable kernel source tree
+dnl check if we can find a build dir for the Linux kernel
+dnl defines LINUX_DIR to the absolute location of a usable kernel build tree
 AC_DEFUN([AS_LINUX_DIR],
 [
        AC_ARG_WITH([linuxdir],
                [AC_HELP_STRING([--with-linuxdir=DIR],
-                       [specify path to Linux source directory])],
+                       [specify path to Linux build directory])],
                [LINUX_DIR="${withval}"],
                [LINUX_DIR=default])
 
        if test "${LINUX_DIR}" != "default" ; then
-               AS_TRY_LINUX_DIR([${LINUX_DIR}], , AC_MSG_ERROR([Linux dir not found]) )
+               AS_TRY_LINUX_DIR([${LINUX_DIR}], , AC_MSG_ERROR([Linux build dir not found]) )
        fi
 
        if test "${LINUX_DIR}" = "default" ; then
@@ -134,15 +139,64 @@ AC_DEFUN([AS_LINUX_DIR],
        fi
 
        if test "${LINUX_DIR}" = "default" ; then
-               AC_MSG_ERROR([Linux source directory not found])
+               AC_MSG_ERROR([Linux build directory not found])
        fi
 
        AC_SUBST(LINUX_DIR)
 ])
 
-dnl check if the given candidate path for a linux source tree is usable
+dnl check if the given candidate path for a linux build tree is usable
 AC_DEFUN([AS_TRY_LINUX_DIR],
-       [AC_MSG_CHECKING(for Linux in $1)
+       [AC_MSG_CHECKING(for Linux build in $1)
+
+       if test -f "$1/Makefile" ; then
+               result=yes
+               $2
+       else
+               result="not found"
+               $3
+       fi
+
+       AC_MSG_RESULT($result)
+])
+
+dnl get the kernel source directory
+dnl $1 is the kernel build directory
+dnl defines LINUX_SRC_DIR to the absolute location of kernel source tree
+AC_DEFUN([AS_LINUX_SRC_DIR],
+[
+       AC_ARG_WITH([linuxsrcdir],
+               [AC_HELP_STRING([--with-linuxsrcdir=DIR],
+                       [specify path to Linux source directory])],
+               [LINUX_SRC_DIR="${withval}"],
+               [LINUX_SRC_DIR=default])
+
+       if test "${LINUX_SRC_DIR}" != "default" ; then
+               AS_TRY_LINUX_SRC_DIR([${LINUX_SRC_DIR}], , AC_MSG_ERROR([Linux source dir not found]) )
+       fi
+
+       if test "${LINUX_SRC_DIR}" = "default" ; then
+               AC_MSG_CHECKING(for separate Linux source and build directory)
+               dir=`sed -n -e 's/^KERNELSRC *:= *\(.*\)/\1/p' "$1/Makefile"`
+               if test -z "$dir"; then
+                       AC_MSG_RESULT([no])
+                       LINUX_SRC_DIR="$1"
+               else
+                       AC_MSG_RESULT([yes])
+                       AS_TRY_LINUX_SRC_DIR([${dir}], [LINUX_SRC_DIR=${dir}], )
+               fi
+       fi
+
+       if test "${LINUX_SRC_DIR}" = "default" ; then
+               AC_MSG_ERROR([Linux source directory not found])
+       fi
+
+       AC_SUBST(LINUX_SRC_DIR)
+])
+
+dnl check if the given candidate path for a linux source tree is usable
+AC_DEFUN([AS_TRY_LINUX_SRC_DIR],
+       [AC_MSG_CHECKING(for Linux source in $1)
 
        if test -f "$1/Makefile" ; then
                result=yes
@@ -671,24 +725,15 @@ AC_DEFUN([AS_LINUX_VERSION_MAJOR_MINOR],
 AC_DEFUN([COMEDI_CHECK_LINUX_KBUILD],
 [
        AC_MSG_CHECKING([for Kbuild support in $1])
-       dnl For combined kernel source and build directory,
-       dnl if $1/scripts/Makefile.build refers to $(<something>)/Kbuild
+       dnl If $1/scripts/Makefile.build refers to $(<something>)/Kbuild
        dnl then we support Kbuild (2.6.10 onwards).
-       dnl For separate kernel source and build directory, if $1/Makefile
-       dnl contains KERNELOUTPUT variable then this is from a separate
-       dnl kernel build directory, so Kbuild is required
-       dnl (but it will not work prior to 2.6.10).
        if grep -q '/Kbuild' "$1/scripts/Makefile.build" 2>/dev/null; then
                AC_MSG_RESULT([yes])
                $2
-       else if grep -q '^KERNELOUTPUT *:=' "$1/Makefile" 2>/dev/null; then
-               AC_MSG_RESULT([yes])
-               $2
        else
                AC_MSG_RESULT([no])
                $3
        fi
-       fi
 ])
 
 # COMEDI_CHECK_PCMCIA_PROBE([LINUX_SOURCE_PATH], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])