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mailing list for the glibc project.
Re: Undefined reference to atexit (FAQ).
- To: glibc-linux at ricardo dot ecn dot wfu dot edu
- Subject: Re: Undefined reference to atexit (FAQ).
- From: Nix <nix at esperi dot demon dot co dot uk>
- Date: 25 Oct 2001 18:46:40 +0100
- References: <20011025135030.68726532.tpeixoto@if.usp.br>
- Reply-To: glibc-linux at ricardo dot ecn dot wfu dot edu
On Thu, 25 Oct 2001, Tiago de Paula Peixoto uttered the following:
> gcc -o test test.c -lssl -lcrypto
> /lib/libdl.so.2: undefined reference to `atexit'
> collect2: ld returned 1 exit status
>
> I know this is a FAQ and all, but libc_nonshared.a is in the right place
> and I don't know why the linker isn't getting to it.
>
> /usr/lib/libc.so reads:
>
> /* GNU ld script
> Use the shared library, but some functions are only in
> the static library, so try that secondarily. */
> GROUP ( /lib/libc.so.6 /usr/lib/libc_nonshared.a )
>
> I'm using glibc-2.2.4, compiled with gcc-2.95.3.
Recompile glibc with gcc-2.94pre from CVS with this patch applied to
GCC, and a recent binutils, and it should work properly. (Unless you
have an alpha; the non-buggy-on-alpha version was posted on the
libc-alpha mailing list shortly after this one, but I foolishly didn't
grab it.)
--- gcc-2.95.x/gcc/config/alpha/crtbegin.asm.jj Wed Dec 16 22:00:53 1998
+++ gcc-2.95.x/gcc/config/alpha/crtbegin.asm Wed Jun 13 12:41:28 2001
@@ -97,6 +97,31 @@ __EH_FRAME_BEGIN__:
# Support recursive calls to exit.
$ptr: .quad __DTOR_LIST__
+/* A globally unique widget for c++ local destructors to hang off.
+
+ This has a unique value in every dso; in the main program its
+ value is zero. The object should be protected. This means the
+ instance in any dso or the main program is not used in any other
+ dso. The dynamic linker takes care of this. */
+
+ .global __dso_handle
+ .type __dso_handle,@object
+ .size __dso_handle,8
+#ifdef SHARED
+.section .data
+ .align 3
+__dso_handle:
+ .quad __dso_handle
+#else
+.section .bss
+ .align 3
+__dso_handle:
+ .zero 8
+#endif
+#ifdef HAVE_GAS_HIDDEN
+ .hidden __dso_handle
+#endif
+
.text
.align 3
============================================================
Index: gcc/crtstuff.c
--- gcc-2.95.x/gcc/crtstuff.c 2001/04/03 10:34:32 1.18.4.1
+++ gcc-2.95.x/gcc/crtstuff.c 2001/08/09 06:56:33
@@ -55,6 +55,7 @@ Boston, MA 02111-1307, USA. */
#include "defaults.h"
#include <stddef.h>
#include "frame.h"
+#include "auto-host.h"
/* We do not want to add the weak attribute to the declarations of these
routines in frame.h because that will cause the definition of these
@@ -134,7 +135,29 @@ typedef void (*func_ptr) (void);
#ifdef INIT_SECTION_ASM_OP
#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. 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_HIDDEN
+asm (".hidden\t__dso_handle");
+#endif
+
+#ifdef CRTSTUFFS_O
+void *__dso_handle = &__dso_handle;
+#else
+void *__dso_handle = 0;
+#endif
+/* The __cxa_finalize function may not be available so we use only a
+ weak declaration. */
+extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
+
/* Run all the global destructors on exit from the program. */
/* Some systems place the number of pointers in the first word of the
@@ -164,6 +187,11 @@ __do_global_dtors_aux (void)
if (completed)
return;
+
+#ifdef CRTSTUFFS_O
+ if (__cxa_finalize)
+ __cxa_finalize (__dso_handle);
+#endif
while (*p)
{
--- gcc-2.95.x/gcc/configure.in.jj Wed Oct 13 09:58:02 1999
+++ gcc-2.95.x/gcc/configure.in Wed Jun 13 12:44:34 2001
@@ -4053,6 +4053,21 @@ EOF
fi
AC_MSG_RESULT($gcc_cv_as_subsections)
+AC_MSG_CHECKING(assembler hidden support)
+gcc_cv_as_hidden=
+if test x$gcc_cv_as != x; then
+ # Check if we have .hidden
+ echo " .hidden foobar" > conftest.s
+ echo "foobar:" >> conftest.s
+ if $gcc_cv_as -o conftest.o conftest.s > /dev/null 2>&1; then
+ AC_DEFINE(HAVE_GAS_HIDDEN, 1,
+ [Define if your assembler supports .hidden.])
+ gcc_cv_as_hidden="yes"
+ fi
+ rm -f conftest.s conftest.o conftest.nm1 conftest.nm2
+fi
+AC_MSG_RESULT($gcc_cv_as_hidden)
+
AC_MSG_CHECKING(assembler instructions)
gcc_cv_as_instructions=
if test x$gcc_cv_as != x; then
--- gcc-2.95.x/gcc/config.in.jj Mon Oct 25 10:02:08 1999
+++ gcc-2.95.x/gcc/config.in Wed Jun 13 12:45:56 2001
2 the beginning of your section */
#undef HAVE_GAS_SUBSECTION_ORDERING
+/* 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
--
`You're the only person I know who can't tell the difference
between a pair of trousers and a desk.' --- Kieran, to me