diff --git a/gcc/config.build b/gcc/config.build
new file mode 100644
index 00000000000..676800cdbcc
--- /dev/null
+++ b/gcc/config.build
@@ -0,0 +1,132 @@
+# GCC build-specific configuration file.
+# Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2003
+# Free Software Foundation, Inc.
+
+#This file is part of GCC.
+
+#GCC is free software; you can redistribute it and/or modify it under
+#the terms of the GNU General Public License as published by the Free
+#Software Foundation; either version 2, or (at your option) any later
+#version.
+
+#GCC is distributed in the hope that it will be useful, but WITHOUT
+#ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+#FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+#for more details.
+
+#You should have received a copy of the GNU General Public License
+#along with GCC; see the file COPYING.  If not, write to the Free
+#Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+#02111-1307, USA.
+
+# This is the GCC build-specific configuration file
+# where a configuration type is mapped to different system-specific
+# definitions and files.  This is invoked by the autoconf-generated
+# configure script.  Putting it in a separate shell file lets us skip
+# running autoconf when modifying build-specific information.
+
+# This file switches on the shell variable ${build}.  As much of this
+# as possible should be replaced with autoconf tests in the future.
+
+# This file sets the following shell variables for use by the
+# autoconf-generated configure script:
+#
+#  build_xm_defines	List of macros to define when compiling for the
+#			build machine.
+#
+#  build_xm_file	List of files to include when compiling for the
+#			build machine.
+#
+#  build_install_headers_dir
+#			Target to use when installing header files.
+#
+#  build_exeext		Set to the suffix, if the build machine requires
+#			executables to have a file name suffix.
+
+# Default settings.
+build_xm_file=
+build_xm_defines=
+build_exeext=
+build_install_headers_dir=install-headers-tar
+
+# System-specific settings.
+case $build in
+  alpha*-dec-osf4*)
+    # Some versions of OSF4 (specifically X4.0-9 296.7) have
+    # a broken tar, so we use cpio instead.
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  alpha*-dec-*vms*)
+    build_xm_file=alpha/xm-vms.h
+    build_exeext=.exe
+    build_install_headers_dir=install-headers-cp
+    prefix=/gnu
+    local_prefix=/gnu
+    ;;
+  hppa1.0-*-hpux1[01]* | \
+  hppa*64*-*-hpux11* | \
+  hppa1.1-*-hpux11* | \
+  hppa2*-*-hpux11* )
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  i370-*-opened* | i370-*-mvs* )
+    # IBM 360/370/390 Architecture
+    build_xm_defines='FATAL_EXIT_CODE=12'
+    ;;
+  i[34567]86-*-cygwin* | i[34567]86-*-pe )
+    build_xm_file=i386/xm-cygwin.h
+    build_exeext=.exe
+    ;;
+  i[34567]86-*-mingw32*)
+    build_xm_file=i386/xm-mingw32.h
+    build_exeext=.exe
+    ;;
+  i[34567]86-pc-msdosdjgpp*)
+    build_xm_file=i386/xm-djgpp.h
+    build_exeext=.exe
+    ;;
+  i[34567]86-*-sco3.2v5*) 
+    # 80386 running SCO Open Server 5
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  i[34567]86-sequent-ptx4* | i[34567]86-sequent-sysv4* )
+    build_xm_defines="SMALL_ARG_MAX"
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  i[34567]86-*-solaris2*)
+    build_xm_defines="SMALL_ARG_MAX"
+    ;;
+  i[34567]86-*-sysv4*) 
+    # Intel x86 running system V r4
+    build_xm_defines="SMALL_ARG_MAX"
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  i[34567]86-*-udk*) 
+    # Intel x86 on SCO UW/OSR5 Dev Kit
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  i[34567]86-*-uwin*)
+    build_exeext=.exe
+    ;;
+  i386-*-vsta) 
+    # Intel 80386's running VSTa kernel
+    build_xm_file="i386/xm-vsta.h"
+    ;;
+  m68000-hp-hpux* | m68k-hp-hpux*) 
+    # HP 9000 series 300
+    build_install_headers_dir=install-headers-cpio
+    ;;
+  mips-sgi-irix5*) 
+    # SGI System V r4, IRIX 5
+    build_xm_file=mips/xm-iris5.h
+    ;;
+  mips-sgi-irix6*o32) 
+    # SGI System V r4, IRIX 6, O32 ABI
+    build_xm_file=mips/xm-iris5.h
+    ;;
+  *-*-sysv*)
+    # All other System V variants.
+    build_install_headers_dir=install-headers-cpio
+    ;;
+esac
+
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 3cee0ca7735..8c9a3414df8 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1,4 +1,4 @@
-# GCC build-, host- and target-specific configuration file.
+# GCC host- and target-specific configuration file.
 # Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2003
 # Free Software Foundation, Inc.
 
@@ -19,13 +19,13 @@
 #Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #02111-1307, USA.
 
-# This is the GCC build-, host- and target-specific configuration file
+# This is the GCC host- and target-specific configuration file
 # where a configuration type, as recognized and generated by config.bfd,
 # is mapped to different system-specific definitions and files.  This is
-# invoked by the autoconf-generated configure script, called for build,
+# invoked by the autoconf-generated configure script, called for
 # host and target in that order, setting ${machine} to each.  Putting it
 # in a separate shell file lets us skip running autoconf when modifying
-# build-, host- and target-specific information.
+# host- and target-specific information.
 
 # This file switches on the shell variable ${machine}, and also uses the
 # following shell variables:
@@ -114,12 +114,6 @@
 #
 #  target_gtfiles       List of extra source files with type information.
 #
-#  build_xm_defines	List of macros to define when compiling for the
-#			build machine.
-#
-#  build_xm_file	List of files to include when compiling for the
-#			build machine.
-#
 #  host_xm_defines	List of macros to define when compiling for the
 #			host machine.
 #
@@ -137,16 +131,10 @@
 #
 #  target_cpu_default	Set to override the default target model.
 #
-#  build_install_headers_dir
-#			Target to use when installing header files.
-#
 #  gdb_needs_out_file_path
 #			Set to yes if gdb needs a dir command with
 #			`dirname $out_file`.
 #
-#  build_exeext		Set to the suffix, if the build machine requires
-#			executables to have a file name suffix.
-#
 #  host_exeext		Set to the suffix, if the host machine requires
 #			executables to have a file name suffix.
 #
@@ -179,8 +167,7 @@
 #  host_hook_obj	An object file that provides the host hooks.
 #
 #  install_headers_dir	Makefile-target for how the header file directory
-#			is installed, when this system is a build system,
-#			for build_install_headers_dir.
+#			is installed.
 #
 #  exeext		The suffix for executables on this system.
 #
@@ -2736,29 +2723,16 @@ then
 	fi
 fi
 
-# Save data on machine being used to compile GCC in build_xm_file.
 # Save data on host machine in vars host_xm_file and host_xmake_file.
-if test x$pass1done = x
-then
-	if test x$xm_file != x
-	then build_xm_file=$xm_file
-	fi
-	build_xm_defines=$xm_defines
-	build_install_headers_dir=$install_headers_dir
-	build_exeext=$exeext
-	pass1done=yes
-else
-	if test x$pass2done = x
-	then
-		if test x$xm_file != x
-		then host_xm_file=$xm_file
-		fi
-		host_xm_defines=$xm_defines
-		host_xmake_file="$xmake_file"
-		host_extra_gcc_objs=$extra_gcc_objs
-		host_extra_objs=$extra_host_objs
-		host_exeext=$exeext
-		out_host_hook_obj=$host_hook_obj
-		pass2done=yes
-	fi
+if test x$pass2done = x ; then
+  if test x$xm_file != x ; then
+    host_xm_file=$xm_file
+  fi
+  host_xm_defines=$xm_defines
+  host_xmake_file="$xmake_file"
+  host_extra_gcc_objs=$extra_gcc_objs
+  host_extra_objs=$extra_host_objs
+  host_exeext=$exeext
+  out_host_hook_obj=$host_hook_obj
+  pass2done=yes
 fi
diff --git a/gcc/configure b/gcc/configure
index 9cc650e466d..d23a64be18a 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -5136,11 +5136,10 @@ fi
 # Build, host, and target specific configuration fragments
 # --------------------------------------------------------
 
+# Collect build-machine-specific information.
+. ${srcdir}/config.build
+
 target_gtfiles=
-build_xm_file=
-build_xm_defines=
-build_install_headers_dir=install-headers-tar
-build_exeext=
 host_xm_file=
 host_xm_defines=
 host_xmake_file=
@@ -5150,7 +5149,7 @@ host_exeext=
 # For the host machine, we save the xm_file variable as host_xm_file;
 # then we decode the target machine and forget everything else
 # that came from the host machine.
-for machine in $build $host $target; do
+for machine in $host $target; do
 	. ${srcdir}/config.gcc
 done
 
@@ -5390,7 +5389,7 @@ if test -f ../intl/config.intl; then
   . ../intl/config.intl
 fi
 echo $ac_n "checking whether NLS is requested""... $ac_c" 1>&6
-echo "configure:5394: checking whether NLS is requested" >&5
+echo "configure:5393: checking whether NLS is requested" >&5
 if test x"$USE_NLS" != xyes; then
   echo "$ac_t""no" 1>&6
 else
@@ -5401,7 +5400,7 @@ EOF
 
 
   echo $ac_n "checking for catalogs to be installed""... $ac_c" 1>&6
-echo "configure:5405: checking for catalogs to be installed" >&5
+echo "configure:5404: checking for catalogs to be installed" >&5
   # Look for .po and .gmo files in the source directory.
   CATALOGS=  
   XLINGUAS=
@@ -5451,7 +5450,7 @@ fi
 case $host_os in
 	win32 | pe | cygwin* | mingw32* | uwin*)
 echo $ac_n "checking whether windows registry support is requested""... $ac_c" 1>&6
-echo "configure:5455: checking whether windows registry support is requested" >&5
+echo "configure:5454: checking whether windows registry support is requested" >&5
 if test "x$enable_win32_registry" != xno; then
   cat >> confdefs.h <<\EOF
 #define ENABLE_WIN32_REGISTRY 1
@@ -5460,14 +5459,14 @@ EOF
   echo "$ac_t""yes" 1>&6
   
 echo $ac_n "checking for library containing RegOpenKeyExA""... $ac_c" 1>&6
-echo "configure:5464: checking for library containing RegOpenKeyExA" >&5
+echo "configure:5463: checking for library containing RegOpenKeyExA" >&5
 if eval "test \"`echo '$''{'ac_cv_search_RegOpenKeyExA'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   ac_func_search_save_LIBS="$LIBS"
 ac_cv_search_RegOpenKeyExA="no"
 cat > conftest.$ac_ext <<EOF
-#line 5471 "configure"
+#line 5470 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -5478,7 +5477,7 @@ int main() {
 RegOpenKeyExA()
 ; return 0; }
 EOF
-if { (eval echo configure:5482: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:5481: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   ac_cv_search_RegOpenKeyExA="none required"
 else
@@ -5489,7 +5488,7 @@ rm -f conftest*
 test "$ac_cv_search_RegOpenKeyExA" = "no" && for i in advapi32; do
 LIBS="-l$i  $ac_func_search_save_LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 5493 "configure"
+#line 5492 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -5500,7 +5499,7 @@ int main() {
 RegOpenKeyExA()
 ; return 0; }
 EOF
-if { (eval echo configure:5504: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:5503: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   ac_cv_search_RegOpenKeyExA="-l$i"
 break
@@ -5542,7 +5541,7 @@ esac
 
 if test "x$enable_win32_registry" != xno; then
   echo $ac_n "checking registry key on windows hosts""... $ac_c" 1>&6
-echo "configure:5546: checking registry key on windows hosts" >&5
+echo "configure:5545: checking registry key on windows hosts" >&5
   cat >> confdefs.h <<EOF
 #define WIN32_REGISTRY_KEY "$gcc_cv_win32_registry_key"
 EOF
@@ -5801,7 +5800,7 @@ esac
 # build->target assembler and hope that it will have the same features
 # as the host->target assembler we'll be using.
 echo $ac_n "checking what assembler to use""... $ac_c" 1>&6
-echo "configure:5805: checking what assembler to use" >&5
+echo "configure:5804: checking what assembler to use" >&5
 in_tree_gas=no
 gcc_cv_as=
 gcc_cv_gas_major_version=
@@ -5925,7 +5924,7 @@ esac
 # build->target linker and hope that it will have the same features
 # as the host->target linker we'll be using.
 echo $ac_n "checking what linker to use""... $ac_c" 1>&6
-echo "configure:5929: checking what linker to use" >&5
+echo "configure:5928: checking what linker to use" >&5
 in_tree_ld=no
 gcc_cv_ld=
 gcc_cv_gld_major_version=
@@ -6033,7 +6032,7 @@ esac
 # Figure out what nm we will be using.
 gcc_cv_binutils_srcdir=`echo $srcdir | sed -e 's,/gcc$,,'`/binutils
 echo $ac_n "checking what nm to use""... $ac_c" 1>&6
-echo "configure:6037: checking what nm to use" >&5
+echo "configure:6036: checking what nm to use" >&5
 in_tree_nm=no
 if test -x nm$host_exeext; then
 	gcc_cv_nm=./nm$host_exeext
@@ -6056,7 +6055,7 @@ esac
 
 # Figure out what objdump we will be using.
 echo $ac_n "checking what objdump to use""... $ac_c" 1>&6
-echo "configure:6060: checking what objdump to use" >&5
+echo "configure:6059: checking what objdump to use" >&5
 in_tree_objdump=no
 if test -x objdump$host_exeext; then
 	gcc_cv_objdump=./objdump$host_exeext
@@ -6081,7 +6080,7 @@ esac
 
 # Figure out what assembler alignment features are present.
 echo $ac_n "checking assembler for .balign and .p2align""... $ac_c" 1>&6
-echo "configure:6085: checking assembler for .balign and .p2align" >&5
+echo "configure:6084: checking assembler for .balign and .p2align" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_balign_and_p2align'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6093,7 +6092,7 @@ fi
   elif test x$gcc_cv_as != x; then
     echo '.balign 4
 .p2align 2' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6097: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6096: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_balign_and_p2align=yes
     else
@@ -6113,7 +6112,7 @@ EOF
 fi
 
 echo $ac_n "checking assembler for .p2align with maximum skip""... $ac_c" 1>&6
-echo "configure:6117: checking assembler for .p2align with maximum skip" >&5
+echo "configure:6116: checking assembler for .p2align with maximum skip" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_max_skip_p2align'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6124,7 +6123,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo '.p2align 4,,7' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6128: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6127: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_max_skip_p2align=yes
     else
@@ -6144,7 +6143,7 @@ EOF
 fi
 
 echo $ac_n "checking assembler for working .subsection -1""... $ac_c" 1>&6
-echo "configure:6148: checking assembler for working .subsection -1" >&5
+echo "configure:6147: checking assembler for working .subsection -1" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_subsection_m1'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6159,7 +6158,7 @@ fi
 .subsection -1
 conftest_label2: .word 0
 .previous' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6163: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6162: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	if test x$gcc_cv_nm != x; then
     $gcc_cv_nm conftest.o | grep conftest_label1 > conftest.nm1
@@ -6187,7 +6186,7 @@ EOF
 fi
 
 echo $ac_n "checking assembler for .weak""... $ac_c" 1>&6
-echo "configure:6191: checking assembler for .weak" >&5
+echo "configure:6190: checking assembler for .weak" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_weak'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6198,7 +6197,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo '	.weak foobar' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6202: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6201: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_weak=yes
     else
@@ -6225,7 +6224,7 @@ fi
 # to be safe.
 # The gcc_GAS_CHECK_FEATURE call just sets a cache variable.
 echo $ac_n "checking assembler for .hidden""... $ac_c" 1>&6
-echo "configure:6229: checking assembler for .hidden" >&5
+echo "configure:6228: checking assembler for .hidden" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_hidden'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6238,7 +6237,7 @@ fi
   elif test x$gcc_cv_as != x; then
     echo '	.hidden foobar
 foobar:' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6242: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6241: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_hidden=yes
     else
@@ -6253,7 +6252,7 @@ echo "$ac_t""$gcc_cv_as_hidden" 1>&6
 
 
 echo $ac_n "checking linker for .hidden support""... $ac_c" 1>&6
-echo "configure:6257: checking linker for .hidden support" >&5
+echo "configure:6256: checking linker for .hidden support" >&5
 if eval "test \"`echo '$''{'gcc_cv_ld_hidden'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6327,7 +6326,7 @@ fi
 
 # Check if we have .[us]leb128, and support symbol arithmetic with it.
 echo $ac_n "checking assembler for .sleb128 and .uleb128""... $ac_c" 1>&6
-echo "configure:6331: checking assembler for .sleb128 and .uleb128" >&5
+echo "configure:6330: checking assembler for .sleb128 and .uleb128" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_leb128'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6344,7 +6343,7 @@ L1:
 	.uleb128 1280
 	.sleb128 -1010
 L2:' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6348: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6347: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	# GAS versions before 2.11 do not support uleb128,
   # despite appearing to.
@@ -6380,7 +6379,7 @@ fi
 # GAS versions up to and including 2.11.0 may mis-optimize
 # .eh_frame data.
 echo $ac_n "checking assembler for eh_frame optimization""... $ac_c" 1>&6
-echo "configure:6384: checking assembler for eh_frame optimization" >&5
+echo "configure:6383: checking assembler for eh_frame optimization" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_eh_frame'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6423,7 +6422,7 @@ __FRAME_BEGIN__:
 	.byte	0x4
 	.4byte	.L1-.LFB1
 .LEFDE1:' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6427: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6426: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	  cat > conftest.lit <<EOF
  0000 10000000 00000000 017a0001 781a0004  .........z..x...
@@ -6444,7 +6443,7 @@ EOF
     || cmp conftest.big conftest.got > /dev/null 2>&1; }
   then
     gcc_cv_as_eh_frame=yes
-  elif { ac_try='$gcc_cv_as -o conftest.o --traditional-format /dev/null'; { (eval echo configure:6448: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
+  elif { ac_try='$gcc_cv_as -o conftest.o --traditional-format /dev/null'; { (eval echo configure:6447: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }; then
     gcc_cv_as_eh_frame=buggy
   else
     # Uh oh, what do we do now?
@@ -6469,7 +6468,7 @@ EOF
 fi
 
 echo $ac_n "checking assembler for section merging support""... $ac_c" 1>&6
-echo "configure:6473: checking assembler for section merging support" >&5
+echo "configure:6472: checking assembler for section merging support" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_shf_merge'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6481,7 +6480,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo '.section .rodata.str, "aMS", @progbits, 1' > conftest.s
-    if { ac_try='$gcc_cv_as --fatal-warnings -o conftest.o conftest.s >&5'; { (eval echo configure:6485: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as --fatal-warnings -o conftest.o conftest.s >&5'; { (eval echo configure:6484: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_shf_merge=yes
     else
@@ -6680,7 +6679,7 @@ if test -z "$tls_first_major"; then
   : # If we don't have a check, assume no support.
 else
   echo $ac_n "checking assembler for thread-local storage support""... $ac_c" 1>&6
-echo "configure:6684: checking assembler for thread-local storage support" >&5
+echo "configure:6683: checking assembler for thread-local storage support" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_tls'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6691,7 +6690,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo "$conftest_s" > conftest.s
-    if { ac_try='$gcc_cv_as $tls_as_opt --fatal-warnings -o conftest.o conftest.s >&5'; { (eval echo configure:6695: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as $tls_as_opt --fatal-warnings -o conftest.o conftest.s >&5'; { (eval echo configure:6694: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_tls=yes
     else
@@ -6717,7 +6716,7 @@ case "$target" in
   # All TARGET_ABI_OSF targets.
   alpha*-*-osf* | alpha*-*-linux* | alpha*-*-*bsd*)
     echo $ac_n "checking assembler for explicit relocation support""... $ac_c" 1>&6
-echo "configure:6721: checking assembler for explicit relocation support" >&5
+echo "configure:6720: checking assembler for explicit relocation support" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_alpha_explicit_relocs'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6740,7 +6739,7 @@ fi
 	ldah	$1, d($29)	!gprelhigh
 	lda	$1, d($1)	!gprellow
 	lda	$29, 0($29)	!gpdisp!3' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6744: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6743: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_alpha_explicit_relocs=yes
     else
@@ -6762,14 +6761,14 @@ fi
 
   sparc*-*-*)
     echo $ac_n "checking assembler for .register""... $ac_c" 1>&6
-echo "configure:6766: checking assembler for .register" >&5
+echo "configure:6765: checking assembler for .register" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_sparc_register_op'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   gcc_cv_as_sparc_register_op=no
   if test x$gcc_cv_as != x; then
     echo '.register %g2, #scratch' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6773: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6772: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_sparc_register_op=yes
     else
@@ -6789,14 +6788,14 @@ EOF
 fi
 
     echo $ac_n "checking assembler for -relax option""... $ac_c" 1>&6
-echo "configure:6793: checking assembler for -relax option" >&5
+echo "configure:6792: checking assembler for -relax option" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_sparc_relax'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   gcc_cv_as_sparc_relax=no
   if test x$gcc_cv_as != x; then
     echo '.text' > conftest.s
-    if { ac_try='$gcc_cv_as -relax -o conftest.o conftest.s >&5'; { (eval echo configure:6800: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as -relax -o conftest.o conftest.s >&5'; { (eval echo configure:6799: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_sparc_relax=yes
     else
@@ -6816,7 +6815,7 @@ EOF
 fi
 
     echo $ac_n "checking assembler for unaligned pcrel relocs""... $ac_c" 1>&6
-echo "configure:6820: checking assembler for unaligned pcrel relocs" >&5
+echo "configure:6819: checking assembler for unaligned pcrel relocs" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_sparc_ua_pcrel'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6829,7 +6828,7 @@ foo:
 .align 4
 .byte 0
 .uaword %r_disp32(foo)' > conftest.s
-    if { ac_try='$gcc_cv_as -K PIC -o conftest.o conftest.s >&5'; { (eval echo configure:6833: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as -K PIC -o conftest.o conftest.s >&5'; { (eval echo configure:6832: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	if test x$gcc_cv_ld != x \
        && $gcc_cv_ld -o conftest conftest.o -G > /dev/null 2>&1; then
@@ -6852,7 +6851,7 @@ EOF
 
 
       echo $ac_n "checking assembler for unaligned pcrel relocs against hidden symbols""... $ac_c" 1>&6
-echo "configure:6856: checking assembler for unaligned pcrel relocs against hidden symbols" >&5
+echo "configure:6855: checking assembler for unaligned pcrel relocs against hidden symbols" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_sparc_ua_pcrel_hidden'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6867,7 +6866,7 @@ else
 .hidden foo
 foo:
 .skip 4' > conftest.s
-    if { ac_try='$gcc_cv_as -K PIC -o conftest.o conftest.s >&5'; { (eval echo configure:6871: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as -K PIC -o conftest.o conftest.s >&5'; { (eval echo configure:6870: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	if test x$gcc_cv_ld != x && test x$gcc_cv_objdump != x \
 	 && $gcc_cv_ld -o conftest conftest.o -G > /dev/null 2>&1 \
@@ -6900,7 +6899,7 @@ fi
 fi # unaligned pcrel relocs
 
     echo $ac_n "checking assembler for offsetable %lo()""... $ac_c" 1>&6
-echo "configure:6904: checking assembler for offsetable %lo()" >&5
+echo "configure:6903: checking assembler for offsetable %lo()" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_sparc_offsetable_lo10'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6909,7 +6908,7 @@ else
     echo '.text
 	or %g1, %lo(ab) + 12, %g1
 	or %g1, %lo(ab + 12), %g1' > conftest.s
-    if { ac_try='$gcc_cv_as -xarch=v9 -o conftest.o conftest.s >&5'; { (eval echo configure:6913: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as -xarch=v9 -o conftest.o conftest.s >&5'; { (eval echo configure:6912: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	if test x$gcc_cv_objdump != x \
        && %gcc_cv_objdump -s -j .text conftest.o 2> /dev/null \
@@ -6935,7 +6934,7 @@ fi
 
   i[34567]86-*-* | x86_64-*-*)
     echo $ac_n "checking assembler for filds and fists mnemonics""... $ac_c" 1>&6
-echo "configure:6939: checking assembler for filds and fists mnemonics" >&5
+echo "configure:6938: checking assembler for filds and fists mnemonics" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_ix86_filds_fists'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6946,7 +6945,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo 'filds mem; fists mem' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6950: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6949: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_ix86_filds_fists=yes
     else
@@ -6968,7 +6967,7 @@ fi
     # This one is used unconditionally by i386.[ch]; it is to be defined
     # to 1 if the feature is present, 0 otherwise.
     echo $ac_n "checking assembler for GOTOFF in data""... $ac_c" 1>&6
-echo "configure:6972: checking assembler for GOTOFF in data" >&5
+echo "configure:6971: checking assembler for GOTOFF in data" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_ix86_gotoff_in_data'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -6983,7 +6982,7 @@ fi
 	nop
 	.data
 	.long .L0@GOTOFF' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6987: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:6986: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_ix86_gotoff_in_data=yes
     else
@@ -7004,7 +7003,7 @@ EOF
 
   ia64*-*-*)
     echo $ac_n "checking assembler for ltoffx and ldxmov relocs""... $ac_c" 1>&6
-echo "configure:7008: checking assembler for ltoffx and ldxmov relocs" >&5
+echo "configure:7007: checking assembler for ltoffx and ldxmov relocs" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_ia64_ltoffx_ldxmov_relocs'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7018,7 +7017,7 @@ fi
 	addl r15 = @ltoffx(x#), gp
 	;;
 	ld8.mov r16 = [r15], x#' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7022: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7021: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_ia64_ltoffx_ldxmov_relocs=yes
     else
@@ -7048,7 +7047,7 @@ fi
 	mfcr 3,128"
 
     echo $ac_n "checking assembler for mfcr field support""... $ac_c" 1>&6
-echo "configure:7052: checking assembler for mfcr field support" >&5
+echo "configure:7051: checking assembler for mfcr field support" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_powerpc_mfcrf'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7059,7 +7058,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo "$conftest_s" > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7063: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7062: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_powerpc_mfcrf=yes
     else
@@ -7081,7 +7080,7 @@ fi
 
   mips*-*-*)
     echo $ac_n "checking assembler for explicit relocation support""... $ac_c" 1>&6
-echo "configure:7085: checking assembler for explicit relocation support" >&5
+echo "configure:7084: checking assembler for explicit relocation support" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_mips_explicit_relocs'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7092,7 +7091,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo '	lw $4,%gp_rel(foo)($4)' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7096: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7095: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_mips_explicit_relocs=yes
     else
@@ -7138,7 +7137,7 @@ if test x"$insn" != x; then
 	.loc 1 3 0
 	$insn"
  echo $ac_n "checking assembler for dwarf2 debug_line support""... $ac_c" 1>&6
-echo "configure:7142: checking assembler for dwarf2 debug_line support" >&5
+echo "configure:7141: checking assembler for dwarf2 debug_line support" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_dwarf2_debug_line'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7150,7 +7149,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo "$conftest_s" > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7154: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7153: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	# ??? This fails with non-gnu grep.  Maybe use objdump?
    if grep debug_line conftest.o > /dev/null 2>&1; then
@@ -7172,7 +7171,7 @@ echo "$ac_t""$gcc_cv_as_dwarf2_debug_line" 1>&6
 # by DW_AT_decl_file.  Approximate this test by testing if
 # the assembler bitches if the same index is assigned twice.
  echo $ac_n "checking assembler for buggy dwarf2 .file directive""... $ac_c" 1>&6
-echo "configure:7176: checking assembler for buggy dwarf2 .file directive" >&5
+echo "configure:7175: checking assembler for buggy dwarf2 .file directive" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_dwarf2_file_buggy'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7180,7 +7179,7 @@ else
   if test x$gcc_cv_as != x; then
     echo '	.file 1 "foo.s"
 	.file 1 "bar.s"' > conftest.s
-    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7184: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'; { (eval echo configure:7183: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_dwarf2_file_buggy=yes
     else
@@ -7203,7 +7202,7 @@ EOF
  fi
 
  echo $ac_n "checking assembler for --gdwarf2 option""... $ac_c" 1>&6
-echo "configure:7207: checking assembler for --gdwarf2 option" >&5
+echo "configure:7206: checking assembler for --gdwarf2 option" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_gdwarf2_flag'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7215,7 +7214,7 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo "$insn" > conftest.s
-    if { ac_try='$gcc_cv_as --gdwarf2 -o conftest.o conftest.s >&5'; { (eval echo configure:7219: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as --gdwarf2 -o conftest.o conftest.s >&5'; { (eval echo configure:7218: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	gcc_cv_as_gdwarf2_flag=yes
     else
@@ -7235,7 +7234,7 @@ EOF
 fi
 
  echo $ac_n "checking assembler for --gstabs option""... $ac_c" 1>&6
-echo "configure:7239: checking assembler for --gstabs option" >&5
+echo "configure:7238: checking assembler for --gstabs option" >&5
 if eval "test \"`echo '$''{'gcc_cv_as_gstabs_flag'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -7247,12 +7246,12 @@ else
 fi
   elif test x$gcc_cv_as != x; then
     echo "$insn" > conftest.s
-    if { ac_try='$gcc_cv_as --gstabs -o conftest.o conftest.s >&5'; { (eval echo configure:7251: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+    if { ac_try='$gcc_cv_as --gstabs -o conftest.o conftest.s >&5'; { (eval echo configure:7250: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
     then
 	# The native Solaris 9/Intel assembler doesn't understand --gstabs
    # and warns about it, but still exits successfully.  So check for
    # this.
-   if { ac_try='$gcc_cv_as --gstabs -o conftest.o conftest.s 2>&1 | grep -i warning > /dev/null'; { (eval echo configure:7256: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
+   if { ac_try='$gcc_cv_as --gstabs -o conftest.o conftest.s 2>&1 | grep -i warning > /dev/null'; { (eval echo configure:7255: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; }
    then :
    else gcc_cv_as_gstabs_flag=yes
    fi
@@ -7274,7 +7273,7 @@ fi
 fi
 
 echo $ac_n "checking linker read-only and read-write section mixing""... $ac_c" 1>&6
-echo "configure:7278: checking linker read-only and read-write section mixing" >&5
+echo "configure:7277: checking linker read-only and read-write section mixing" >&5
 gcc_cv_ld_ro_rw_mix=unknown
 if test $in_tree_ld = yes ; then
   if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" -ge 10 -o "$gcc_cv_gld_major_version" -gt 2 \
@@ -7313,7 +7312,7 @@ fi
 echo "$ac_t""$gcc_cv_ld_ro_rw_mix" 1>&6
 
 echo $ac_n "checking linker PT_GNU_EH_FRAME support""... $ac_c" 1>&6
-echo "configure:7317: checking linker PT_GNU_EH_FRAME support" >&5
+echo "configure:7316: checking linker PT_GNU_EH_FRAME support" >&5
 gcc_cv_ld_eh_frame_hdr=no
 if test $in_tree_ld = yes ; then
   if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" -ge 12 -o "$gcc_cv_gld_major_version" -gt 2 \
@@ -7335,7 +7334,7 @@ fi
 echo "$ac_t""$gcc_cv_ld_eh_frame_hdr" 1>&6
 
 echo $ac_n "checking linker position independent executable support""... $ac_c" 1>&6
-echo "configure:7339: checking linker position independent executable support" >&5
+echo "configure:7338: checking linker position independent executable support" >&5
 gcc_cv_ld_pie=no
 if test $in_tree_ld = yes ; then
   if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" -ge 15 -o "$gcc_cv_gld_major_version" -gt 2 \
@@ -7360,7 +7359,7 @@ echo "$ac_t""$gcc_cv_ld_pie" 1>&6
 case "$target" in
   mips*-*-*)
     echo $ac_n "checking whether libgloss uses STARTUP directives consistently""... $ac_c" 1>&6
-echo "configure:7364: checking whether libgloss uses STARTUP directives consistently" >&5
+echo "configure:7363: checking whether libgloss uses STARTUP directives consistently" >&5
     gcc_cv_mips_libgloss_startup=no
     gcc_cv_libgloss_srcdir=`echo $srcdir | sed -e 's,/gcc$,,'`/libgloss
     if test "x$exec_prefix" = xNONE; then
@@ -7565,7 +7564,7 @@ fi
 
 
 echo $ac_n "checking whether to enable maintainer-specific portions of Makefiles""... $ac_c" 1>&6
-echo "configure:7569: checking whether to enable maintainer-specific portions of Makefiles" >&5
+echo "configure:7568: checking whether to enable maintainer-specific portions of Makefiles" >&5
     # Check whether --enable-maintainer-mode or --disable-maintainer-mode was given.
 if test "${enable_maintainer_mode+set}" = set; then
   enableval="$enable_maintainer_mode"
diff --git a/gcc/configure.in b/gcc/configure.in
index 01d3e49a50f..69884b2f79f 100644
--- a/gcc/configure.in
+++ b/gcc/configure.in
@@ -962,11 +962,10 @@ fi
 # Build, host, and target specific configuration fragments
 # --------------------------------------------------------
 
+# Collect build-machine-specific information.
+. ${srcdir}/config.build
+
 target_gtfiles=
-build_xm_file=
-build_xm_defines=
-build_install_headers_dir=install-headers-tar
-build_exeext=
 host_xm_file=
 host_xm_defines=
 host_xmake_file=
@@ -976,7 +975,7 @@ host_exeext=
 # For the host machine, we save the xm_file variable as host_xm_file;
 # then we decode the target machine and forget everything else
 # that came from the host machine.
-for machine in $build $host $target; do
+for machine in $host $target; do
 	. ${srcdir}/config.gcc
 done
 
diff --git a/gcc/doc/fragments.texi b/gcc/doc/fragments.texi
index c9ebcf9145d..379703cf618 100644
--- a/gcc/doc/fragments.texi
+++ b/gcc/doc/fragments.texi
@@ -13,7 +13,7 @@ construct the file @file{Makefile} from the template file
 fragments from the @file{config} directory.  These are used to set
 Makefile parameters that are not amenable to being calculated by
 autoconf.  The list of fragments to incorporate is set by
-@file{config.gcc}; @xref{System Config}.
+@file{config.gcc} (and occasionally @file{config.build}); @xref{System Config}.
 
 Fragments are named either @file{t-@var{target}} or @file{x-@var{host}},
 depending on whether they are relevant to configuring GCC to produce
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 7ef35f9b717..b5a11a94a3e 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -175,7 +175,7 @@ timestamp.
 
 @menu
 * Config Fragments::     Scripts used by @file{configure}.
-* System Config::        The @file{config.gcc} file.
+* System Config::        The @file{config.build} and @file{config.gcc} files.
 * Configuration Files::  Files created by running @file{configure}.
 @end menu
 
@@ -191,10 +191,12 @@ files, kept in the top level directory, are used.  FIXME: when is the
 the top level one) used?
 
 @item The file @file{config.gcc} is used to handle configuration
-specific to the particular build, host or target machine.  (In
-general, this should only be used for features that cannot reasonably
-be tested in Autoconf feature tests.)  @xref{System Config, , The
-@file{config.gcc} File}, for details of the contents of this file.
+specific to the particular host or target machine.  The file 
+@file{config.build} is used to handle configuration specific to the 
+particular build machine.  (In general, these should only be used for 
+features that cannot reasonably be tested in Autoconf feature tests.)
+@xref{System Config, , The @file{config.build} and @file{config.gcc} Files},
+for details of the contents of these files.
 
 @item Each language subdirectory has a file
 @file{@var{language}/config-lang.in} that is used for
@@ -206,9 +208,9 @@ creating the output of @file{configure}.
 @end itemize
 
 @node System Config
-@subsubsection The @file{config.gcc} File
+@subsubsection The @file{config.build} and @file{config.gcc} Files
 
-FIXME: document the contents of this file, and what variables should
+FIXME: document the contents of these files, and what variables should
 be set to control build, host and target configuration.
 
 @include configfiles.texi