__dso_handle (Ignore last patch)

[Ulrich Drepper]

Almost everything from the last mail is OK, but the patch isn't.  I
was just educated that the visibility rules for symbols are a bit
different than I thought and so using .hidden instead of .protected is
the better solution.

-- 
---------------.      drepper at gnu.org  ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2000-04-04  Ulrich Drepper  <drepper@cygnus.com>

	* acconfig.h: Add HAVE_GAS_HIDDEN.
	* config.h: Regenerated.
	* configure.in: Add test for .hidden pseudo-op in gas.
	* crtstuff.c: Include auto-host.h.
	Emit additional .hidden pseudo-op for __dso_handle if the
	assembler knows about it.

Index: acconfig.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/acconfig.h,v
retrieving revision 1.43
diff -u -u -r1.43 acconfig.h
--- acconfig.h	2000/03/16 01:58:12	1.43
+++ acconfig.h	2000/04/04 23:12:58
@@ -72,6 +72,9 @@
 /* Define if your assembler supports .weak.  */
 #undef HAVE_GAS_WEAK
 
+/* Define if your assembler supports .hidden.  */
+#undef HAVE_GAS_HIDDEN
+
 /* Define if your assembler uses the old HImode fild and fist notation.  */
 #undef HAVE_GAS_FILDS_FISTS
 
Index: config.in
===================================================================
RCS file: /cvs/gcc/egcs/gcc/config.in,v
retrieving revision 1.62
diff -u -u -r1.62 config.in
--- config.in	2000/03/16 01:58:13	1.62
+++ config.in	2000/04/04 23:13:00
@@ -73,6 +73,9 @@
 /* Define if your assembler supports .weak.  */
 #undef HAVE_GAS_WEAK
 
+/* Define if your assembler supports .hidden.  */
+#undef HAVE_GAS_HIDDEN
+
 /* Define if your assembler uses the old HImode fild and fist notation.  */
 #undef HAVE_GAS_FILDS_FISTS
 
Index: configure.in
===================================================================
RCS file: /cvs/gcc/egcs/gcc/configure.in,v
retrieving revision 1.349
diff -u -u -r1.349 configure.in
--- configure.in	2000/03/30 22:31:36	1.349
+++ configure.in	2000/04/04 23:13:36
@@ -4414,6 +4414,20 @@
 fi
 AC_MSG_RESULT($gcc_cv_as_weak)
 
+AC_MSG_CHECKING(assembler hidden support)
+gcc_cv_as_protected=
+if test x$gcc_cv_as != x; then
+	# Check if we have .hidden
+	echo "	.hidden symbol" > conftest.s
+	echo "symbol:" >> conftest.s
+	if $gcc_cv_as -o conftest.o conftest.s > /dev/null 2>&1; then
+		AC_DEFINE(HAVE_GAS_HIDDEN)
+		gcc_cv_as_hidden="yes"
+	fi
+	rm -f conftest.s conftest.o conftest.nm1 conftest.nm2
+fi
+AC_MSG_RESULT($gcc_cv_as_hidden)
+
 case "$target" in 
   sparc*-*-*)
     AC_CACHE_CHECK([assembler .register pseudo-op support],
Index: crtstuff.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/crtstuff.c,v
retrieving revision 1.26
diff -u -u -r1.26 crtstuff.c
--- crtstuff.c	2000/02/26 05:59:31	1.26
+++ crtstuff.c	2000/04/04 23:13:38
@@ -52,6 +52,7 @@
    compiled for the target, and hence definitions concerning only the host
    do not apply.  */
 
+#include "auto-host.h"
 #include "tm.h"
 #include "tsystem.h"
 
@@ -132,7 +133,17 @@
 #ifdef OBJECT_FORMAT_ELF
 
 /* Declare the __dso_handle variable.  It should have a unique value
-   in every shared-object; in a main program its value is zero.  */
+   in every shared-object; in a main program its value is zero.  The
+   object should in any case be protected.  This means the instance
+   in one DSO or the main program is not used in another object.  The
+   dynamic linker takes care of this.  */
+
+/* XXX Ideally the following should be implemented using
+	__attribute__ ((__visibility__ ("hidden")))
+   but the __attribute__ support is not yet there.  */
+#ifdef HAVE_GAS_PROTECTED
+asm (".hidden\t__dso_handle");
+#endif
 
 #ifdef CRTSTUFFS_O
 void *__dso_handle = &__dso_handle;