diff --git a/ChangeLog b/ChangeLog
index a39ed0276..428536114 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2010-10-02  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
+
+	PR bootstrap/45326
+	PR bootstrap/45174
+	* configure.ac: Honor initial values of $build_configargs,
+	$host_configargs, $target_configargs.  Mark the precious, so
+	environment settings get recorded.
+	* configure: Regenerate.
+
 2010-10-02  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
 	Sync from GCC:
diff --git a/configure b/configure
index a959aca38..7762106f9 100755
--- a/configure
+++ b/configure
@@ -655,12 +655,9 @@ CFLAGS_FOR_BUILD
 CC_FOR_BUILD
 AS_FOR_BUILD
 AR_FOR_BUILD
-target_configargs
 target_configdirs
 configdirs
-host_configargs
 build_configdirs
-build_configargs
 INSTALL_GDB_TK
 GDB_TK
 CONFIGURE_GDB_TK
@@ -668,6 +665,9 @@ build_tooldir
 tooldir
 GCC_SHLIB_SUBDIR
 RPATH_ENVVAR
+target_configargs
+host_configargs
+build_configargs
 BUILD_CONFIG
 CXXFLAGS_FOR_TARGET
 CFLAGS_FOR_TARGET
@@ -835,6 +835,9 @@ CXX
 CXXFLAGS
 CCC
 CPP
+build_configargs
+host_configargs
+target_configargs
 AR
 AS
 DLLTOOL
@@ -1569,6 +1572,12 @@ Some influential environment variables:
   CXX         C++ compiler command
   CXXFLAGS    C++ compiler flags
   CPP         C preprocessor
+  build_configargs
+              additional configure arguments for build directories
+  host_configargs
+              additional configure arguments for host directories
+  target_configargs
+              additional configure arguments for target directories
   AR          AR for the host
   AS          AS for the host
   DLLTOOL     DLLTOOL for the host
@@ -7916,10 +7925,15 @@ if test "$silent" = yes; then
 fi
 baseargs="$baseargs --disable-option-checking"
 
+# Record and document user additions to sub configure arguments.
+
+
+
+
 # For the build-side libraries, we just need to pretend we're native,
 # and not use the same cache file.  Multilibs are neither needed nor
 # desired.
-build_configargs="--cache-file=../config.cache ${baseargs}"
+build_configargs="$build_configargs --cache-file=../config.cache ${baseargs}"
 
 # For host modules, accept cache file option, or specification as blank.
 case "${cache_file}" in
@@ -7933,9 +7947,9 @@ esac
 
 # Host dirs don't like to share a cache file either, horribly enough.
 # This seems to be due to autoconf 2.5x stupidity.
-host_configargs="--cache-file=./config.cache ${extra_host_args} ${baseargs}"
+host_configargs="$host_configargs --cache-file=./config.cache ${extra_host_args} ${baseargs}"
 
-target_configargs=${baseargs}
+target_configargs="$target_configargs ${baseargs}"
 
 # Passing a --with-cross-host argument lets the target libraries know
 # whether they are being built with a cross-compiler or being built
diff --git a/configure.ac b/configure.ac
index be7e992f5..6af4be17a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2969,10 +2969,18 @@ if test "$silent" = yes; then
 fi
 baseargs="$baseargs --disable-option-checking"
 
+# Record and document user additions to sub configure arguments.
+AC_ARG_VAR([build_configargs],
+	   [additional configure arguments for build directories])
+AC_ARG_VAR([host_configargs],
+	   [additional configure arguments for host directories])
+AC_ARG_VAR([target_configargs],
+	   [additional configure arguments for target directories])
+
 # For the build-side libraries, we just need to pretend we're native,
 # and not use the same cache file.  Multilibs are neither needed nor
 # desired.
-build_configargs="--cache-file=../config.cache ${baseargs}"
+build_configargs="$build_configargs --cache-file=../config.cache ${baseargs}"
 
 # For host modules, accept cache file option, or specification as blank.
 case "${cache_file}" in
@@ -2986,9 +2994,9 @@ esac
 
 # Host dirs don't like to share a cache file either, horribly enough.
 # This seems to be due to autoconf 2.5x stupidity.
-host_configargs="--cache-file=./config.cache ${extra_host_args} ${baseargs}"
+host_configargs="$host_configargs --cache-file=./config.cache ${extra_host_args} ${baseargs}"
 
-target_configargs=${baseargs}
+target_configargs="$target_configargs ${baseargs}"
 
 # Passing a --with-cross-host argument lets the target libraries know
 # whether they are being built with a cross-compiler or being built