re PR libgcj/25816 (Configure detects TLS, but glibc does not support it.)

	PR java/25816
	* configure.ac (enable_tls): New enable option.
	(HAVE_AS_TLS): Don't do assembler check if enable_tls set.
	* configure: Regenerate.
	* doc/install.texi (--enable-tls): Document new option.
	(--disable-tls): Ditto.

From-SVN: r110199

gcc/ChangeLog

+2006-01-24  David Daney  <ddaney@avtrex.com>
+
+	PR java/25816
+	* configure.ac (enable_tls): New enable option.
+	(HAVE_AS_TLS): Don't do assembler check if enable_tls set.
+	* configure: Regenerate.
+	* doc/install.texi (--enable-tls): Document new option.
+	(--disable-tls): Ditto.
+
 2006-01-24  Richard Henderson  <rth@redehat.com>
 
 	* alias.h (ALIAS_SET_MEMORY_BARRIER): New.

gcc/configure.ac

@@ -679,6 +679,17 @@ AC_ARG_ENABLE(threads,
   --enable-threads=LIB    use LIB thread package for target GCC],,
 [enable_threads=''])
 
+AC_ARG_ENABLE(tls,
+[  --enable-tls            enable or disable generation of tls code
+                          overriding the assembler check for tls support],
+[
+  case $enable_tls in
+    yes | no) ;;
+    *) AC_MSG_ERROR(['$enable_tls' is an invalid value for --enable-tls.
+Valid choices are 'yes' and 'no'.]) ;;
+  esac
+], [enable_tls=''])
+
 AC_ARG_ENABLE(objc-gc,
 [  --enable-objc-gc	  enable the use of Boehm's garbage collector with
 			  the GNU Objective-C runtime],
@@ -2531,13 +2542,21 @@ foo:	.long	25
 	;;
 changequote([,])dnl
 esac
-if test -z "$tls_first_major"; then
+set_have_as_tls=no
+if test "x$enable_tls" = xno ; then
+  : # TLS explicitly disabled.
+elif test "x$enable_tls" = xyes ; then
+  set_have_as_tls=yes # TLS explicitly enabled.
+elif test -z "$tls_first_major"; then
   : # If we don't have a check, assume no support.
 else
   gcc_GAS_CHECK_FEATURE(thread-local storage support, gcc_cv_as_tls,
   [$tls_first_major,$tls_first_minor,0], [$tls_as_opt], [$conftest_s],,
-  [AC_DEFINE(HAVE_AS_TLS, 1,
-	    [Define if your assembler supports thread-local storage.])])
+  [set_have_as_tls=yes])
+fi
+if test $set_have_as_tls = yes ; then
+  AC_DEFINE(HAVE_AS_TLS, 1,
+	    [Define if your assembler supports thread-local storage.])
 fi
 
 # Target-specific assembler checks.

gcc/doc/install.texi

@@ -945,6 +945,18 @@ Microsoft Win32 API thread support.
 Novell Kernel Services thread support.
 @end table
 
+@item --enable-tls
+Specify that the target supports TLS (Thread Local Storage).  Usually
+configure can correctly determine if TLS is supported.  In cases where
+it guesses incorrectly, TLS can be explicitly enabled or disabled with
+@option{--enable-tls} or @option{--disable-tls}.  This can happen if
+the assembler supports TLS but the C library does not, or if the
+assumptions made by the configure test are incorrect.
+
+@item --disable-tls
+Specify that the target does not support TLS.
+This is an alias for @option{--enable-tls=no}.
+
 @item --with-cpu=@var{cpu}
 Specify which cpu variant the compiler should generate code for by default.
 @var{cpu} will be used as the default value of the @option{-mcpu=} switch.