From: Ben Hutchings <ben@decadent.org.uk>
Subject: [PATCH] Change configure script to use Kbuild for compile tests
Last-Update: 2010-05-23

Kbuild is the only proper way to build modules.  Calling the compiler
directly will tend to result in false negatives.

Index: alsa-driver-1.0.23+dfsg/configure.in
===================================================================
--- alsa-driver-1.0.23+dfsg.orig/configure.in	2010-05-28 19:14:23.000000000 +0200
+++ alsa-driver-1.0.23+dfsg/configure.in	2010-05-28 19:14:23.000000000 +0200
@@ -1654,11 +1654,6 @@
 fi
 AC_SUBST(msmp)
 
-KERNEL_CHECK_CFLAGS="-Wall -fno-strict-aliasing $CFLAGS $KERNEL_INC $HACK_KERNEL_INC -Iinclude -nostdinc -iwithprefix include"
-if test "$NEW_KBUILD" = "y"; then
-  KERNEL_CHECK_CFLAGS="$KERNEL_CHECK_CFLAGS -DKBUILD_STR(s)=#s -DKBUILD_BASENAME=KBUILD_STR(dummy) -DKBUILD_MODNAME=KBUILD_BASENAME"
-fi
-
 dnl Check for video device support... (2.2 kernels excluded due to API incompatibility)
 if test $kpatchlevel -gt 2; then
 CHECK_KERNEL_CONFIG(CONFIG_VIDEO_DEV, [Video device support in kernel])
@@ -1735,20 +1730,32 @@
 fi
 AC_SUBST(CONFIG_PNP)
 
+dnl Replacement for AC_TRY_COMPILE using kbuild
+AC_DEFUN([KBUILD_TRY_COMPILE], [
+dir="$(mktemp -d)"
+if test -z "$dir"; then
+  echo >&2 "failed to create temporary directory"
+  exit 1
+fi
+echo >"$dir"/test.c '[$1]
+void not_main(void)
+{
+	[$2];
+}'
+echo >"$dir"/Makefile 'obj-y += test.o
+EXTRA_CFLAGS := [$5]'
+if make -C "$CONFIG_SND_KERNELDIR" SUBDIRS="$dir" >&5 2>&1; then
+  [$3]
+else
+  [$4]
+fi
+rm -rf "$dir"
+])
+
 dnl Check for strlcpy...
 AC_MSG_CHECKING(for strlcpy)
 strlcpy="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/kernel.h>
 #include <linux/string.h>
 ],[
@@ -1757,10 +1764,8 @@
 ],
     AC_MSG_RESULT(yes);strlcpy="1",
     AC_MSG_RESULT(no);strlcpy="0",
-    AC_MSG_RESULT(unknown);strlcpy="0"
+    -Werror
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_STRLCPY=$strlcpy
 dnl AC_SUBST(CONFIG_HAVE_STRLCPY)
 if test "$CONFIG_HAVE_STRLCPY" = "1"; then
@@ -1770,17 +1775,7 @@
 dnl Check for snprintf...
 AC_MSG_CHECKING(for snprintf)
 snprintf="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/kernel.h>
 ],[
   char buf[128];
@@ -1788,10 +1783,8 @@
 ],
     AC_MSG_RESULT(yes);snprintf="1",
     AC_MSG_RESULT(no);snprintf="0",
-    AC_MSG_RESULT(unknown);snprintf="0"
+    -Werror
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_SNPRINTF=$snprintf
 dnl AC_SUBST(CONFIG_HAVE_SNPRINTF)
 if test "$CONFIG_HAVE_SNPRINTF" = "1"; then
@@ -1801,17 +1794,7 @@
 dnl Check for vsnprintf...
 AC_MSG_CHECKING(for vsnprintf)
 vsnprintf="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/kernel.h>
 void f(const char *fmt, ...)
 {
@@ -1826,10 +1809,8 @@
 ],
     AC_MSG_RESULT(yes);vsnprintf="1",
     AC_MSG_RESULT(no);vsnprintf="0",
-    AC_MSG_RESULT(unknown);vsnprintf="0"
+    -Werror
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_VSNPRINTF=$vsnprintf
 dnl AC_SUBST(CONFIG_HAVE_VSNPRINTF)
 if test "$CONFIG_HAVE_VSNPRINTF" = "1"; then
@@ -1839,17 +1820,7 @@
 dnl Check for scnprintf...
 AC_MSG_CHECKING(for scnprintf)
 scnprintf="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/kernel.h>
 ],[
   char buf[128];
@@ -1857,10 +1828,8 @@
 ],
     AC_MSG_RESULT(yes);scnprintf="1",
     AC_MSG_RESULT(no);scnprintf="0",
-    AC_MSG_RESULT(unknown);scnprintf="0"
+    -Werror
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_SCNPRINTF=$scnprintf
 dnl AC_SUBST(CONFIG_HAVE_SCNPRINTF)
 if test "$CONFIG_HAVE_SCNPRINTF" = "1"; then
@@ -1870,17 +1839,7 @@
 dnl Check for sscanf...
 AC_MSG_CHECKING(for sscanf)
 sscanf="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/kernel.h>
 ],[
   unsigned int i;
@@ -1888,10 +1847,8 @@
 ],
     AC_MSG_RESULT(yes);sscanf="1",
     AC_MSG_RESULT(no);sscanf="0",
-    AC_MSG_RESULT(unknown);sscanf="0"
+    -Werror
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_SSCANF=$sscanf
 dnl AC_SUBST(CONFIG_HAVE_SSCANF)
 if test "$CONFIG_HAVE_SSCANF" = "1"; then
@@ -1901,17 +1858,7 @@
 dnl Check for vmalloc_to_page...
 AC_MSG_CHECKING(for vmalloc_to_page)
 vmalloc_to_page="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/time.h>
 #include <linux/sched.h>
 #include <linux/interrupt.h>
@@ -1922,10 +1869,7 @@
 ],
     AC_MSG_RESULT(yes);vmalloc_to_page="1",
     AC_MSG_RESULT(no);vmalloc_to_page="0",
-    AC_MSG_RESULT(unknown);vmalloc_to_page="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_VMALLOC_TO_PAGE=$vmalloc_to_page
 dnl AC_SUBST(CONFIG_HAVE_VMALLOC_TO_PAGE)
 if test "$CONFIG_HAVE_VMALLOC_TO_PAGE" = "1"; then
@@ -1935,27 +1879,14 @@
 dnl Check for old kmod...
 AC_MSG_CHECKING(for old kmod)
 old_kmod="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/kmod.h>
 ],[
 	request_module("abcd", "def", "ixj");
 ],
     AC_MSG_RESULT(no);old_kmod="0",
     AC_MSG_RESULT(yes);old_kmod="1",
-    AC_MSG_RESULT(unknown);old_kmod="1"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_OLD_REQUEST_MODULE=$old_kmod
 dnl AC_SUBST(CONFIG_HAVE_OLD_REQUEST_MODULE)
 if test "$CONFIG_HAVE_OLD_REQUEST_MODULE" = "1"; then
@@ -1965,17 +1896,7 @@
 dnl Check for PDE...
 AC_MSG_CHECKING(for PDE)
 pde_defined="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/fs.h>
 #include <linux/proc_fs.h>
 ],[
@@ -1984,10 +1905,7 @@
 ],
     AC_MSG_RESULT(yes);pde_defined="1",
     AC_MSG_RESULT(no);pde_defined="0",
-    AC_MSG_RESULT(unknown);pde_defined="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_PDE=$pde_defined
 dnl AC_SUBST(CONFIG_HAVE_PDE)
 if test "$CONFIG_HAVE_PDE" = "1"; then
@@ -1997,17 +1915,7 @@
 dnl Check for pci_consistent_set_dma_mask()
 AC_MSG_CHECKING(for pci_set_consistent_dma_mask)
 pci_consistent_defined="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/pci.h>
 ],[
 	int (*func)();
@@ -2015,10 +1923,7 @@
 ],
     AC_MSG_RESULT(yes);pci_consistent_defined="1",
     AC_MSG_RESULT(no);pci_consistent_defined="0",
-    AC_MSG_RESULT(unknown);pci_consistent_defined="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_PCI_CONSISTENT_DMA_MASK=$pci_consistent_defined
 if test "$CONFIG_HAVE_PCI_CONSISTENT_DMA_MASK" = "1"; then
   AC_DEFINE(CONFIG_HAVE_PCI_CONSISTENT_DMA_MASK)
@@ -2027,17 +1932,7 @@
 dnl Check for pci_set_dev_present()
 AC_MSG_CHECKING(for pci_dev_present)
 pci_consistent_defined="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/pci.h>
 ],[
 	int (*func)();
@@ -2045,10 +1940,7 @@
 ],
     AC_MSG_RESULT(yes);pci_dev_present_defined="1",
     AC_MSG_RESULT(no);pci_dev_present_defined="0",
-    AC_MSG_RESULT(unknown);pci_dev_present_defined="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_PCI_DEV_PRESENT=$pci_dev_present_defined
 if test "$CONFIG_HAVE_PCI_DEV_PRESENT" = "1"; then
   AC_DEFINE(CONFIG_HAVE_PCI_DEV_PRESENT)
@@ -2057,17 +1949,7 @@
 dnl Check for msleep
 AC_MSG_CHECKING(for msleep)
 msleep="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/delay.h>
 ],[
   void (*func)(unsigned int);
@@ -2075,10 +1957,7 @@
 ],
     AC_MSG_RESULT(yes);msleep="1",
     AC_MSG_RESULT(no);msleep="0",
-    AC_MSG_RESULT(unknown);msleep="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_MSLEEP=$msleep
 dnl AC_SUBST(CONFIG_HAVE_MSLEEP)
 if test "$CONFIG_HAVE_MSLEEP" = "1"; then
@@ -2089,17 +1968,7 @@
 if test "$CONFIG_HAVE_MSLEEP" = "1"; then
 AC_MSG_CHECKING(for msleep_interrupt)
 msleep_interrupt="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/delay.h>
 ],[
   unsigned long (*func)(unsigned int);
@@ -2107,10 +1976,7 @@
 ],
     AC_MSG_RESULT(yes);msleep_interruptible="1",
     AC_MSG_RESULT(no);msleep_interruptible="0",
-    AC_MSG_RESULT(unknown);msleep_interruptible="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_MSLEEP_INTERRUPTIBLE=$msleep_interruptible
 dnl AC_SUBST(CONFIG_HAVE_MSLEEP_INTERRUPTIBLE)
 if test "$CONFIG_HAVE_MSLEEP_INTERRUPTIBLE" = "1"; then
@@ -2121,17 +1987,7 @@
 dnl Check for msecs_to_jiffies
 AC_MSG_CHECKING(for msecs_to_jiffies)
 msecs_to_jiffies="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Iinclude"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/jiffies.h>
 #include <linux/time.h>
 ],[
@@ -2140,10 +1996,8 @@
 ],
     AC_MSG_RESULT(yes);msecs_to_jiffies="1",
     AC_MSG_RESULT(no);msecs_to_jiffies="0",
-    AC_MSG_RESULT(unknown);msecs_to_jiffies="0"
+    -Iinclude
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_MSECS_TO_JIFFIES=$msecs_to_jiffies
 dnl AC_SUBST(CONFIG_HAVE_MSECS_TO_JIFFIES)
 if test "$CONFIG_HAVE_MSECS_TO_JIFFIES" = "1"; then
@@ -2153,17 +2007,7 @@
 dnl Check for tty->count is the atomic type
 AC_MSG_CHECKING(for tty->count is the atomic type)
 tty_count_atomic="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/tty.h>
 ],[
 	struct tty_struct tty;
@@ -2171,10 +2015,7 @@
 ],
     AC_MSG_RESULT(yes);tty_count_atomic="1",
     AC_MSG_RESULT(no);tty_count_atomic="0",
-    AC_MSG_RESULT(unknown);tty_count_atomic="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_TTY_COUNT_ATOMIC=$tty_count_atomic
 if test "$CONFIG_HAVE_TTY_COUNT_ATOMIC" = "1"; then
   AC_DEFINE(CONFIG_HAVE_TTY_COUNT_ATOMIC)
@@ -2184,17 +2025,7 @@
 if test "$CONFIG_VIDEO_DEV" = "y"; then
 AC_MSG_CHECKING(for video_get_drvdata)
 video_get_drvdata="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Iinclude"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/videodev.h>
 #include "media/v4l2-dev.h"
 ],[
@@ -2203,10 +2034,8 @@
 ],
     AC_MSG_RESULT(yes);video_get_drvdata="1",
     AC_MSG_RESULT(no);video_get_drvdata="0",
-    AC_MSG_RESULT(unknown);video_get_drvdata="0"
+    -Iinclude
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_VIDEO_GET_DRVDATA=$video_get_drvdata
 dnl AC_SUBST(CONFIG_HAVE_VIDEO_GET_DRVDATA)
 if test "$CONFIG_HAVE_VIDEO_GET_DRVDATA" = "1"; then
@@ -2218,17 +2047,7 @@
 if test "$CONFIG_HAVE_VIDEO_GET_DRVDATA" = "1"; then
 AC_MSG_CHECKING(for video_drvdata)
 video_drvdata="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Iinclude"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/videodev.h>
 #include "media/v4l2-dev.h"
 ],[
@@ -2237,10 +2056,8 @@
 ],
     AC_MSG_RESULT(yes);video_drvdata="1",
     AC_MSG_RESULT(no);video_drvdata="0",
-    AC_MSG_RESULT(unknown);video_drvdata="0"
+    -Iinclude
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_VIDEO_DRVDATA=$video_drvdata
 dnl AC_SUBST(CONFIG_HAVE_VIDEO_DRVDATA)
 if test "$CONFIG_HAVE_VIDEO_DRVDATA" = "1"; then
@@ -2269,17 +2086,7 @@
 dnl Check for old io_remap_page_range()
 AC_MSG_CHECKING(for io_remap_pfn_range)
 io_remap_pfn_range="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror-implicit-function-declaration"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/mm.h>
 ],[
   static pgprot_t p;
@@ -2287,10 +2094,8 @@
 ],
     AC_MSG_RESULT(yes);io_remap_pfn_range="1",
     AC_MSG_RESULT(no);io_remap_pfn_range="0",
-    AC_MSG_RESULT(unknown);io_remap_pfn_range="0"
+    -Werror-implicit-function-declaration
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 if test "$io_remap_pfn_range" = "1"; then
   AC_DEFINE(CONFIG_HAVE_IO_REMAP_PFN_RANGE)
 fi
@@ -2298,17 +2103,7 @@
 if test "$io_remap_pfn_range" != "1"; then
 AC_MSG_CHECKING(for new io_remap_page_range)
 new_io_remap="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS -Werror-implicit-function-declaration"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/mm.h>
 ],[
   static pgprot_t p;
@@ -2316,10 +2111,8 @@
 ],
     AC_MSG_RESULT(yes);new_io_remap="1",
     AC_MSG_RESULT(no);new_io_remap="0",
-    AC_MSG_RESULT(unknown);new_io_remap="0"
+    -Werror-implicit-function-declaration
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 if test "$new_io_remap" != "1"; then
   AC_DEFINE(CONFIG_OLD_IO_REMAP_PAGE_RANGE)
 fi
@@ -2328,17 +2121,7 @@
 dnl Check for kcalloc()
 AC_MSG_CHECKING(for kcalloc)
 kcalloc="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/slab.h>
 ],[
   void * (*func)(size_t, size_t, int);
@@ -2346,10 +2129,7 @@
 ],
     AC_MSG_RESULT(yes);kcalloc="1",
     AC_MSG_RESULT(no);kcalloc="0",
-    AC_MSG_RESULT(unknown);kcalloc="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_KCALLOC=$kcalloc
 dnl AC_SUBST(CONFIG_HAVE_KCALLOC)
 if test "$CONFIG_HAVE_KCALLOC" = "1"; then
@@ -2359,17 +2139,7 @@
 dnl Check for kstrdup()
 AC_MSG_CHECKING(for kstrdup)
 kstrdup="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/string.h>
 ],[
   char * (*func)(const char *, int);
@@ -2377,10 +2147,7 @@
 ],
     AC_MSG_RESULT(yes);kstrdup="1",
     AC_MSG_RESULT(no);kstrdup="0",
-    AC_MSG_RESULT(unknown);kstrdup="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_KSTRDUP=$kstrdup
 dnl AC_SUBST(CONFIG_HAVE_KSTRDUP)
 if test "$CONFIG_HAVE_KSTRDUP" = "1"; then
@@ -2390,13 +2157,7 @@
 dnl Check for kstrdup()
 AC_MSG_CHECKING(for kstrndup)
 kstrdup="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#include <linux/config.h>
+KBUILD_TRY_COMPILE([
 #include <linux/string.h>
 ],[
   char * (*func)(const char *, int);
@@ -2404,10 +2165,7 @@
 ],
     AC_MSG_RESULT(yes);kstrndup="1",
     AC_MSG_RESULT(no);kstrndup="0",
-    AC_MSG_RESULT(unknown);kstrndup="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_KSTRNDUP=$kstrndup
 dnl AC_SUBST(CONFIG_HAVE_KSTNRDUP)
 if test "$CONFIG_HAVE_KSTRNDUP" = "1"; then
@@ -2417,17 +2175,7 @@
 dnl Check for kzalloc()
 AC_MSG_CHECKING(for kzalloc)
 kzalloc="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/slab.h>
 ],[
   void * (*func)(size_t, int);
@@ -2435,10 +2183,7 @@
 ],
     AC_MSG_RESULT(yes);kzalloc="1",
     AC_MSG_RESULT(no);kzalloc="0",
-    AC_MSG_RESULT(unknown);kzalloc="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_KZALLOC=$kzalloc
 dnl AC_SUBST(CONFIG_HAVE_KZALLOC)
 if test "$CONFIG_HAVE_KZALLOC" = "1"; then
@@ -2449,27 +2194,14 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
 AC_MSG_CHECKING(for create_workqueue with flags)
 workqueue2="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/workqueue.h>
 ],[
     create_workqueue("abcd", 0);
 ],
     AC_MSG_RESULT(yes);workqueue2="1",
     AC_MSG_RESULT(no);workqueue2="0",
-    AC_MSG_RESULT(unknown);workqueue2="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_CREATE_WORKQUEUE_FLAGS=$workqueue2
 dnl AC_SUBST(CONFIG_CREATE_WORKQUEUE_FLAGS)
 if test "$CONFIG_CREATE_WORKQUEUE_FLAGS" = "1"; then
@@ -2480,17 +2212,7 @@
 dnl Check for pci_ioremap_bar
 AC_MSG_CHECKING(for pci_ioremap_bar)
 pci_ioremap_bar="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/pci.h>
 ],[
   void (*func)(struct pci_dev *, int);
@@ -2498,10 +2220,7 @@
 ],
     AC_MSG_RESULT(yes);pci_ioremap_bar="1",
     AC_MSG_RESULT(no);pci_ioremap_bar="0",
-    AC_MSG_RESULT(unknown);pci_ioremap_bar="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_PCI_IOREMAP_BAR=$pci_ioremap_bar
 dnl AC_SUBST(CONFIG_HAVE_PCI_IOREMAP_BAR)
 if test "$CONFIG_HAVE_PCI_IOREMAP_BAR" = "1"; then
@@ -2511,17 +2230,7 @@
 dnl Check for saved_config_space in pci_dev
 AC_MSG_CHECKING(for saved_config_space in pci_dev)
 pci_saved_config="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/pci.h>
 ],[
   struct pci_dev dev;
@@ -2529,10 +2238,7 @@
 ],
     AC_MSG_RESULT(yes);pci_saved_config="1",
     AC_MSG_RESULT(no);pci_saved_config="0",
-    AC_MSG_RESULT(unknown);pci_saved_config="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_PCI_SAVED_CONFIG=$pci_saved_config
 dnl AC_SUBST(CONFIG_HAVE_PCI_SAVED_CONFIG)
 if test "$CONFIG_HAVE_PCI_SAVED_CONFIG" = "1"; then
@@ -2543,17 +2249,7 @@
 dnl Check for new pci_save_state()
 AC_MSG_CHECKING(for new pci_save_state)
 new_pci_save_state="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/pci.h>
 ],[
   struct pci_dev *pci;
@@ -2561,10 +2257,7 @@
 ],
     AC_MSG_RESULT(yes);new_pci_save_state="1",
     AC_MSG_RESULT(no);new_pci_save_state="0",
-    AC_MSG_RESULT(unknown);new_pci_save_state="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 if test "$new_pci_save_state" = "1"; then
   AC_DEFINE(CONFIG_HAVE_NEW_PCI_SAVE_STATE)
 fi
@@ -2573,17 +2266,7 @@
 dnl Check for register_sound_special_device
 AC_MSG_CHECKING(for register_sound_special_device)
 msleep="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/sound.h>
 ],[
   void (*func)(struct file_operations *, int, struct device *);
@@ -2591,10 +2274,7 @@
 ],
     AC_MSG_RESULT(yes);reg_sp="1",
     AC_MSG_RESULT(no);reg_sp="0",
-    AC_MSG_RESULT(unknown);reg_sp="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_REGISTER_SOUND_SPECIAL_DEVICE=$reg_sp
 dnl AC_SUBST(CONFIG_HAVE_REGISTER_SOUND_SPECIAL_DEVICE)
 if test "$CONFIG_HAVE_REGISTER_SOUND_SPECIAL_DEVICE" = "1"; then
@@ -2607,20 +2287,7 @@
 dnl Check for old kill_fasync...
 AC_MSG_CHECKING(for old kill_fasync)
 oldkfasync="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$CFLAGS $KERNEL_INC $HACK_KERNEL_INC"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
-#ifdef __alpha__ /* it's required (at least for 2.2.18) */
-#include <asm/current.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/fs.h>
 ],[
  struct fasync_struct *fa;
@@ -2629,10 +2296,7 @@
 ],
     AC_MSG_RESULT(yes);oldkfasync="1",
     AC_MSG_RESULT(no);oldkfasync="0",
-    AC_MSG_RESULT(unknown);oldkfasync="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_OLD_KILL_FASYNC=$oldkfasync
 dnl AC_SUBST(CONFIG_OLD_KILL_FASYNC)
 if test "$CONFIG_OLD_KILL_FASYNC" = "1"; then
@@ -2642,27 +2306,14 @@
 dnl Check for dma_addr_t
 AC_MSG_CHECKING(for dma_addr_t)
 dma_addr_t="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$CFLAGS $KERNEL_INC $HACK_KERNEL_INC"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <asm/types.h>
 ],[
  dma_addr_t addr;
 ],
     AC_MSG_RESULT(yes);dma_addr_t="1",
     AC_MSG_RESULT(no);dma_addr_t="0",
-    AC_MSG_RESULT(unknown);dma_addr_t="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_DMA_ADDR_T=$dma_addr_t
 dnl AC_SUBST(CONFIG_HAVE_DMA_ADDR_T)
 if test "$CONFIG_HAVE_DMA_ADDR_T" = "1"; then
@@ -2672,17 +2323,7 @@
 dnl Check for MUTEX macros
 AC_MSG_CHECKING(for MUTEX macros)
 have_mutex_macros="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$CFLAGS $KERNEL_INC $HACK_KERNEL_INC"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <asm/semaphore.h>
 ],[
 #ifndef init_MUTEX
@@ -2692,10 +2333,7 @@
 ],
     AC_MSG_RESULT(yes);have_mutex_macros="1",
     AC_MSG_RESULT(no);have_mutex_macros="0",
-    AC_MSG_RESULT(unknown);have_mutex_macros="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_MUTEX_MACROS=$have_mutex_macros
 dnl AC_SUBST(CONFIG_HAVE_MUTEX_MACROS)
 if test "$CONFIG_HAVE_MUTEX_MACROS" = "1"; then
@@ -2890,17 +2528,7 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for class_simple)
   class_simple="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/device.h>
 ],[
   struct class_simple *(*foo)(struct module *, char *) = class_simple_create;
@@ -2908,10 +2536,7 @@
 ],
     AC_MSG_RESULT(yes);class_simple="1",
     AC_MSG_RESULT(no);class_simple="0",
-    AC_MSG_RESULT(unknown);class_simple="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_HAVE_CLASS_SIMPLE=$class_simple
   dnl AC_SUBST(CONFIG_SND_HAVE_CLASS_SIMPLE)
   if test "$CONFIG_SND_HAVE_CLASS_SIMPLE" = "1"; then
@@ -2923,17 +2548,7 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for old driver suspend/resume callbacks)
   old_driver_suspend="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/device.h>
 ],[
   static struct device_driver driver;
@@ -2941,10 +2556,7 @@
 ],
     AC_MSG_RESULT(yes);old_driver_suspend="1",
     AC_MSG_RESULT(no);old_driver_suspend="0",
-    AC_MSG_RESULT(unknown);old_driver_suspend="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_OLD_DRIVER_SUSPEND=$old_driver_suspend
   dnl AC_SUBST(CONFIG_SND_OLD_DRIVER_SUSPEND)
   if test "$CONFIG_SND_OLD_DRIVER_SUSPEND" = "1"; then
@@ -2956,27 +2568,14 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for removal of page-reservation for nopage/mmap)
   remove_page_reserve="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/mm.h>
 ],[
   void (*func)(struct vm_area_struct *, pte_t, unsigned long) = print_bad_pte;
 ],
     AC_MSG_RESULT(yes);remove_page_reserve="1",
     AC_MSG_RESULT(no);remove_page_reserve="0",
-    AC_MSG_RESULT(unknown);remove_page_reserve="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_REMOVE_PAGE_RESERVE=$remove_page_reserve
   dnl AC_SUBST(CONFIG_SND_REMOVE_PAGE_RESERVE)
   if test "$CONFIG_SND_REMOVE_PAGE_RESERVE" = "1"; then
@@ -2988,17 +2587,7 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for nested class_device)
   nested_class_device="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/device.h>
 ],[
   struct class_device dev;
@@ -3006,10 +2595,7 @@
 ],
     AC_MSG_RESULT(yes);nested_class_device="1",
     AC_MSG_RESULT(no);nested_class_device="0",
-    AC_MSG_RESULT(unknown);nested_class_device="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_NESTED_CLASS_DEVICE=$nested_class_device
   dnl AC_SUBST(CONFIG_SND_NESTED_CLASS_DEVICE)
   if test "$CONFIG_SND_NESTED_CLASS_DEVICE" = "1"; then
@@ -3021,17 +2607,7 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for new IRQ handler)
   new_irq_handler="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/interrupt.h>
 ],[
   irq_handler_t handle = 0;
@@ -3039,10 +2615,7 @@
 ],
     AC_MSG_RESULT(yes);new_irq_handler="1",
     AC_MSG_RESULT(no);new_irq_handler="0",
-    AC_MSG_RESULT(unknown);new_irq_handler="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_NEW_IRQ_HANDLER=$new_irq_handler
   dnl AC_SUBST(CONFIG_SND_NEW_IRQ_HANDLER)
   if test "$CONFIG_SND_NEW_IRQ_HANDLER" = "1"; then
@@ -3053,17 +2626,7 @@
 dnl Check for gfp_t...
 AC_MSG_CHECKING(for gfp_t)
 gfp_t="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/types.h>
 #include <linux/gfp.h>
 ],[
@@ -3071,10 +2634,7 @@
 ],
     AC_MSG_RESULT(yes);gfp_t="1",
     AC_MSG_RESULT(no);gfp_t="0",
-    AC_MSG_RESULT(unknown);gfp_t="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_GFP_T=$gfp_t
 dnl AC_SUBST(CONFIG_HAVE_GFP_T)
 if test "$CONFIG_HAVE_GFP_T" = "1"; then
@@ -3084,17 +2644,7 @@
 dnl Check for GFP_DMA32...
 AC_MSG_CHECKING(for GFP_DMA32)
 gfp_dma32="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/types.h>
 #include <linux/gfp.h>
 ],[
@@ -3102,10 +2652,7 @@
 ],
     AC_MSG_RESULT(yes);gfp_dma32="1",
     AC_MSG_RESULT(no);gfp_dma32="0",
-    AC_MSG_RESULT(unknown);gfp_dma32="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_GFP_DMA32=$gfp_dma32
 dnl AC_SUBST(CONFIG_HAVE_GFP_DMA32)
 if test "$CONFIG_HAVE_GFP_DMA32" = "1"; then
@@ -3115,17 +2662,7 @@
 dnl Check for page_to_pfn...
 AC_MSG_CHECKING(for page_to_pfn)
 page_to_pfn="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+KBUILD_TRY_COMPILE([
 #include <linux/types.h>
 #include <linux/mm.h>
 ],[
@@ -3135,10 +2672,7 @@
 ],
     AC_MSG_RESULT(yes);page_to_pfn="1",
     AC_MSG_RESULT(no);page_to_pfn="0",
-    AC_MSG_RESULT(unknown);page_to_pfn="0"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_HAVE_PAGE_TO_PFN=$page_to_pfn
 dnl AC_SUBST(CONFIG_HAVE_PAGE_TO_PFN)
 if test "$CONFIG_HAVE_PAGE_TO_PFN" = "1"; then
@@ -3151,20 +2685,7 @@
 else
 AC_MSG_CHECKING(for init_utsname)
   init_utsname="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-  if test "$CONFIG_HAVE_DEPRECATED_CONFIG_H" = "1"; then
-    CFLAGS="$CFLAGS -DCONFIG_HAVE_DEPRECATED_CONFIG_H=1"
-  fi
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/utsname.h>
 ],[
   int *x = (int *)init_utsname();
@@ -3172,10 +2693,8 @@
 ],
     AC_MSG_RESULT(yes);init_utsname="1",
     AC_MSG_RESULT(no);init_utsname="0",
-    AC_MSG_RESULT(unknown);init_utsname="0"
+    -Werror
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_HAVE_INIT_UTSNAME=$init_utsname
 fi
 dnl AC_SUBST(CONFIG_HAVE_INIT_UTSNAME)
@@ -3189,17 +2708,7 @@
 else
 AC_MSG_CHECKING(for is_power_of_2)
   is_power_of_2="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS -Werror"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/log2.h>
 ],[
   int a = is_power_of_2(2);
@@ -3207,10 +2716,8 @@
 ],
     AC_MSG_RESULT(yes);is_power_of_2="1",
     AC_MSG_RESULT(no);is_power_of_2="0",
-    AC_MSG_RESULT(unknown);is_power_of_2="0"
+    -Werror
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_HAVE_IS_POWER_OF_2=$is_power_of_2
 fi
 dnl AC_SUBST(CONFIG_HAVE_IS_POWER_OF_2)
@@ -3224,17 +2731,7 @@
 else
   AC_MSG_CHECKING(for __ffs)
   have_ffs="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/bitops.h>
 ],[
   unsigned long (*x)(unsigned long);
@@ -3242,10 +2739,7 @@
 ],
     AC_MSG_RESULT(yes);have_ffs="1",
     AC_MSG_RESULT(no);have_ffs="0",
-    AC_MSG_RESULT(unknown);have_ffs="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_HAVE_FFS=$have_ffs
 fi
 dnl AC_SUBST(CONFIG_HAVE_FFS)
@@ -3257,17 +2751,7 @@
 if test "$CONFIG_PNP_KERNEL" = "y"; then
   AC_MSG_CHECKING(for PnP suspend/resume)
   pnp_suspend="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/pnp.h>
 ],[
   struct pnp_driver pnp;
@@ -3275,10 +2759,7 @@
 ],
     AC_MSG_RESULT(yes);pnp_suspend="1",
     AC_MSG_RESULT(no);pnp_suspend="0",
-    AC_MSG_RESULT(unknown);pnp_suspend="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_HAVE_PNP_SUSPEND=$pnp_suspend
   dnl AC_SUBST(CONFIG_HAVE_PNP_SUSPEND)
   if test "$CONFIG_HAVE_PNP_SUSPEND" = "1"; then
@@ -3290,27 +2771,14 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for device_create_drvdata)
   device_create_drvdata="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/device.h>
 ],[
   struct device *(*foo)() = device_create_drvdata;
 ],
     AC_MSG_RESULT(yes);device_create_drvdata="1",
     AC_MSG_RESULT(no);device_create_drvdata="0",
-    AC_MSG_RESULT(unknown);device_create_drvdata="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_HAS_DEVICE_CREATE_DRVDATA=$device_create_drvdata
   if test "$CONFIG_SND_HAS_DEVICE_CREATE_DRVDATA" = "1"; then
     AC_DEFINE(CONFIG_SND_HAS_DEVICE_CREATE_DRVDATA)
@@ -3322,17 +2790,7 @@
 if test "$kversion.$kpatchlevel" = "2.6"; then
   AC_MSG_CHECKING(for new unlocked/compat_ioctl)
   new_ioctl="0"
-  ac_save_CFLAGS="$CFLAGS"
-  ac_save_CC="$CC"
-  CFLAGS="$KERNEL_CHECK_CFLAGS"
-  CC=$KCC
-  AC_TRY_COMPILE([
-#define __KERNEL__
-#ifdef CONFIG_HAVE_DEPRECATED_CONFIG_H
-#include <$INCLUDE_AUTOCONF_H>
-#else
-#include <linux/config.h>
-#endif
+  KBUILD_TRY_COMPILE([
 #include <linux/fs.h>
 ],[
   struct file_operations ops;
@@ -3341,10 +2799,7 @@
 ],
     AC_MSG_RESULT(yes);new_ioctl="1",
     AC_MSG_RESULT(no);new_ioctl="0",
-    AC_MSG_RESULT(unknown);new_ioctl="0"
 )
-  CFLAGS=$ac_save_CFLAGS
-  CC=$ac_save_CC
   CONFIG_SND_HAVE_NEW_IOCTL=$new_ioctl
   dnl AC_SUBST(CONFIG_SND_HAVE_NEW_IOCTL)
   if test "$CONFIG_SND_HAVE_NEW_IOCTL" = "1"; then
@@ -3356,20 +2811,13 @@
 dnl compiler support for _Bool
 AC_MSG_CHECKING(for builtin _Bool support)
 builtin_bool="0"
-ac_save_CFLAGS="$CFLAGS"
-ac_save_CC="$CC"
-CFLAGS="$KERNEL_CHECK_CFLAGS"
-CC=$KCC
-AC_TRY_COMPILE([],[
+KBUILD_TRY_COMPILE([],[
   _Bool b;
   b = (_Bool)0;
 ],
   AC_MSG_RESULT(yes);builtin_bool="1",
   AC_MSG_RESULT(no);builtin_bool="0",
-  AC_MSG_RESULT(unknown);builtin_bool="1"
 )
-CFLAGS=$ac_save_CFLAGS
-CC=$ac_save_CC
 CONFIG_SND_HAS_BUILTIN_BOOL=$builtin_bool
 if test "$CONFIG_SND_HAS_BUILTIN_BOOL" = "1"; then
   AC_DEFINE(CONFIG_SND_HAS_BUILTIN_BOOL)