Modified TLS-test slightly: the program checking for TLS support is now compiled...

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

diff --git a/configure.in b/configure.in
index 5cbae4466adab1e350cd9c251ab70f76ef5c550f..1bdbde754eac4c2fb39cfe28708c4f5268669255 100644 (file)
--- 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])