config/

[pf3gnuchains/gcc-fork.git] / config / tls.m4

diff --git a/config/tls.m4 b/config/tls.m4
index b7a0730..b6c4c4a 100644 (file)
--- a/config/tls.m4
+++ b/config/tls.m4
@@ -2,20 +2,87 @@ dnl Check whether the target supports TLS.
 AC_DEFUN([GCC_CHECK_TLS], [
   GCC_ENABLE(tls, yes, [], [Use thread-local storage])
   AC_CACHE_CHECK([whether the target supports thread-local storage],
-                have_tls, [
+                gcc_cv_have_tls, [
     AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
       [dnl If the test case passed with dynamic linking, try again with
-      dnl static linking.  This fails at least with some older Red Hat
-      dnl releases.
-      save_LDFLAGS="$LDFLAGS"
+       dnl static linking, but only if static linking is supported (not
+       dnl on Solaris 10).  This fails with some older Red Hat releases.
+      chktls_save_LDFLAGS="$LDFLAGS"
       LDFLAGS="-static $LDFLAGS"
-      AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
-                   [have_tls=yes], [have_tls=no], [])
-      LDFLAGS="$save_LDFLAGS"],
-      [have_tls=no],
-      [AC_COMPILE_IFELSE([__thread int foo;], [have_tls=yes], [have_tls=no])]
+      AC_LINK_IFELSE([int main() { return 0; }],
+       AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
+                     [gcc_cv_have_tls=yes], [gcc_cv_have_tls=no],[]),
+       [gcc_cv_have_tls=yes])
+      LDFLAGS="$chktls_save_LDFLAGS"
+      if test $gcc_cv_have_tls = yes; then
+       dnl So far, the binutils and the compiler support TLS.
+       dnl Also check whether the libc supports TLS, i.e. whether a variable
+       dnl with __thread linkage has a different address in different threads.
+       dnl First, find the thread_CFLAGS necessary for linking a program that
+       dnl calls pthread_create.
+       chktls_save_CFLAGS="$CFLAGS"
+       thread_CFLAGS=failed
+       for flag in '' '-pthread' '-lpthread'; do
+         CFLAGS="$flag $chktls_save_CFLAGS"
+         AC_LINK_IFELSE(
+           [AC_LANG_PROGRAM(
+              [#include <pthread.h>
+               void *g(void *d) { return NULL; }],
+              [pthread_t t; pthread_create(&t,NULL,g,NULL);])],
+           [thread_CFLAGS="$flag"])
+         if test "X$thread_CFLAGS" != Xfailed; then
+           break
+         fi
+       done
+       CFLAGS="$chktls_save_CFLAGS"
+       if test "X$thread_CFLAGS" != Xfailed; then
+         CFLAGS="$thread_CFLAGS $chktls_save_CFLAGS"
+         AC_RUN_IFELSE(
+           [AC_LANG_PROGRAM(
+              [#include <pthread.h>
+               __thread int a;
+               static int *a_in_other_thread;
+               static void *
+               thread_func (void *arg)
+               {
+                 a_in_other_thread = &a;
+                 return (void *)0;
+               }],
+              [pthread_t thread;
+               void *thread_retval;
+               int *a_in_main_thread;
+               if (pthread_create (&thread, (pthread_attr_t *)0,
+                                   thread_func, (void *)0))
+                 return 0;
+               a_in_main_thread = &a;
+               if (pthread_join (thread, &thread_retval))
+                 return 0;
+               return (a_in_other_thread == a_in_main_thread);])],
+            [gcc_cv_have_tls=yes], [gcc_cv_have_tls=no], [])
+         CFLAGS="$chktls_save_CFLAGS"
+       fi
+      fi],
+      [gcc_cv_have_tls=no],
+      [dnl This is the cross-compiling case. Assume libc supports TLS if the
+       dnl binutils and the compiler do.
+       AC_LINK_IFELSE([__thread int a; int b; int main() { return a = b; }],
+                     [gcc_cv_have_tls=yes], [gcc_cv_have_tls=no])
+      ]
     )])
-  if test "$enable_tls $have_tls" = "yes yes"; then
+  if test "$enable_tls $gcc_cv_have_tls" = "yes yes"; then
     AC_DEFINE(HAVE_TLS, 1,
              [Define to 1 if the target supports thread-local storage.])
   fi])
+
+dnl Check whether the target assembler supports TLS.
+AC_DEFUN([GCC_CHECK_CC_TLS], [
+  GCC_ENABLE(tls, yes, [], [Use thread-local storage])
+  AC_CACHE_CHECK([whether the target asssembler upports thread-local storage],
+                gcc_cv_have_cc_tls, [
+    AC_COMPILE_IFELSE([__thread int a; int b; int main() { return a = b; }],
+      [gcc_cv_have_cc_tls=yes], [gcc_cv_have_cc_tls=no])]
+    )])
+  if test "$enable_tls $gcc_cv_have_cc_tls" = "yes yes"; then
+    AC_DEFINE(HAVE_CC_TLS, 1,
+             [Define to 1 if the target assembler supports thread-local storage.])
+  fi])