From: Bart Van Assche <bvanassche@acm.org>
Date: Mon, 2 Jun 2008 07:14:20 +0000 (+0000)
Subject: Modified TLS-test slightly: the program checking for TLS support is now compiled... 
X-Git-Tag: svn/VALGRIND_3_4_0~527
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=463381c162781b561a8b884533c16536ee675174;p=thirdparty%2Fvalgrind.git

Modified TLS-test slightly: the program checking for TLS support is now compiled, linked and run when compiling natively and compiled and linked only when cross-compiling. Before it was compiled and linked only, both for native and cross-compilation.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@8172
---

diff --git a/configure.in b/configure.in
index 5cbae4466a..1bdbde754e 100644
--- a/configure.in
+++ b/configure.in
@@ -1149,6 +1149,19 @@ AM_CONDITIONAL(BUILD_SSSE3_TESTS, test x$ac_have_as_ssse3 = xyes)
 
 
 # Check for TLS support in the compiler and linker
+if test "x${cross_compiling}" = "xno"; then
+# Native compilation: check whether running a program using TLS succeeds.
+# Linking only is not sufficient -- e.g. on Red Hat 7.3 linking TLS programs
+# succeeds but running programs using TLS fails.
+AC_CACHE_CHECK([for TLS support], vg_cv_tls,
+	       [AC_ARG_ENABLE(tls, [  --enable-tls            platform supports TLS],
+		[vg_cv_tls=$enableval],
+               	[AC_RUN_IFELSE([AC_LANG_PROGRAM([[static __thread int foo;]],
+                                                [[return foo;]])],
+                               [vg_cv_tls=yes],
+                               [vg_cv_tls=no])])])
+else
+# Cross-compiling: check whether linking a program using TLS succeeds.
 AC_CACHE_CHECK([for TLS support], vg_cv_tls,
 	       [AC_ARG_ENABLE(tls, [  --enable-tls            platform supports TLS],
 		[vg_cv_tls=$enableval],
@@ -1156,6 +1169,7 @@ AC_CACHE_CHECK([for TLS support], vg_cv_tls,
                                                 [[return foo;]])],
                                [vg_cv_tls=yes],
                                [vg_cv_tls=no])])])
+fi
 
 if test "$vg_cv_tls" = yes; then
 AC_DEFINE([HAVE_TLS], 1, [can use __thread to define thread-local variables])