An important patch for glibc 2.0

[hjl@lucon.org (H.J. Lu)]

> 
> hjl@lucon.org (H.J. Lu) writes:
> 
> > Ok, it is not needed if we can copy elf/so*.c from glibc 2.1
> > to glibc 2.0. Ulrich, can we do that?
> 
> We could do this but I don't want to release any 2.0.* version anymore.
> 

Here is a patch. You don't have to make a new release. In fact, we
haven't had one since glibc 2.0.6. Just put it into CVS so that
RedHat/Debian/SuSE can get it if they want. I have a patch for egcs,
which depends on it.

I believe we have to maintain glibc 2.0 at least for a while since
there are so many users now. I don't think they can/will switch to
glibc 2.1 anytime soon. 

Thanks.


H.J.
---
Fri Dec 11 07:39:39 1998  H.J. Lu  (hjl@gnu.org)

	* elf/soinit.c: Copied from glibc 2.1.
	* elf/sofini.c: Likewise.

	* config.h.in (HAVE_DWARF2_UNWIND_INFO): New.
	(HAVE_DWARF2_UNWIND_INFO_STATIC): New.

	* configure.in (HAVE_DWARF2_UNWIND_INFO): Check for it.
	(HAVE_DWARF2_UNWIND_INFO_STATIC): Check for it.
	* configure: Regenerated.

Index: elf/soinit.c
===================================================================
RCS file: /home/work/cvs/gnu/glibc-2.0/elf/soinit.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 soinit.c
--- elf/soinit.c	1997/09/19 18:10:34	1.1.1.1
+++ elf/soinit.c	1998/12/11 15:34:32
@@ -17,6 +17,28 @@
     (**list) ();
 }
 
+#ifdef HAVE_DWARF2_UNWIND_INFO
+static char __EH_FRAME_BEGIN__[]
+     __attribute__ ((section (".eh_frame")))
+     = { };
+# ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
+/* This must match what's in frame.h in gcc. How can one do that? */
+struct object
+{
+  void *pc_begin;
+  void *pc_end;
+  void *fde_begin;
+  void *fde_array;
+  __SIZE_TYPE__ count;
+  struct object *next;
+};
+extern void __register_frame_info (const void *, struct object *);
+extern void __deregister_frame_info (const void *);
+# else
+extern void __register_frame (const void *);
+extern void __deregister_frame (const void *);
+# endif
+#endif
 
 /* This function will be called from _init in init-first.c.  */
 void
@@ -24,6 +46,16 @@
 {
   /* Call constructor functions.  */
   run_hooks (__CTOR_LIST__);
+#ifdef HAVE_DWARF2_UNWIND_INFO
+# ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
+  {
+    static struct object ob;
+    __register_frame_info (__EH_FRAME_BEGIN__, &ob);
+  }
+# else
+  __register_frame (__EH_FRAME_BEGIN__);
+# endif
+#endif
 }
 
 
@@ -35,4 +67,11 @@
 {
   /* Call destructor functions.  */
   run_hooks (__DTOR_LIST__);
+#ifdef HAVE_DWARF2_UNWIND_INFO
+# ifdef HAVE_DWARF2_UNWIND_INFO_STATIC
+  __deregister_frame_info (__EH_FRAME_BEGIN__);
+# else
+  __deregister_frame (__EH_FRAME_BEGIN__);
+# endif
+#endif
 }
Index: elf/sofini.c
===================================================================
RCS file: /home/work/cvs/gnu/glibc-2.0/elf/sofini.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 sofini.c
--- elf/sofini.c	1997/09/19 18:10:34	1.1.1.1
+++ elf/sofini.c	1998/12/11 15:34:32
@@ -7,3 +7,13 @@
 static void (*const __DTOR_END__[1]) (void)
      __attribute__ ((unused, section (".dtors")))
      = { 0 };
+
+#ifdef HAVE_DWARF2_UNWIND_INFO
+/* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
+   this would be the 'length' field in a real FDE.  */
+
+typedef unsigned int ui32 __attribute__ ((mode (SI)));
+static ui32 __FRAME_END__[1]
+     __attribute__ ((unused, section (".eh_frame")))
+     = { 0 };
+#endif
Index: config.h.in
===================================================================
RCS file: /home/work/cvs/gnu/glibc-2.0/config.h.in,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 config.h.in
--- config.h.in	1997/12/12 20:44:09	1.1.1.2
+++ config.h.in	1998/12/11 15:33:46
@@ -46,6 +46,13 @@
 /* Define to the prefix Alpha/ELF GCC emits before ..ng symbols.  */
 #undef  ASM_ALPHA_NG_SYMBOL_PREFIX
 
+/* Define if gcc uses DWARF2 unwind information for exception support.  */
+#undef  HAVE_DWARF2_UNWIND_INFO
+     
+/* Define if gcc uses DWARF2 unwind information for exception support
+   with static variable. */
+#undef  HAVE_DWARF2_UNWIND_INFO_STATIC
+
 /*
  */
 
Index: configure.in
===================================================================
RCS file: /home/work/cvs/gnu/glibc-2.0/configure.in,v
retrieving revision 1.1.1.7
diff -u -r1.1.1.7 configure.in
--- configure.in	1998/05/20 21:50:24	1.1.1.7
+++ configure.in	1998/12/11 15:30:27
@@ -759,6 +759,61 @@
 rm -f conftest*])
 AC_SUBST(libc_cv_ld_no_whole_archive)dnl
 
+AC_CACHE_CHECK(for DWARF2 unwind info support, libc_cv_gcc_dwarf2_unwind_info,
+[cat > conftest.c <<EOF
+#line __oline__ "configure"
+static char __EH_FRAME_BEGIN__[];
+_start ()
+{
+#ifdef CHECK__register_frame
+  __register_frame (__EH_FRAME_BEGIN__);
+  __deregister_frame (__EH_FRAME_BEGIN__);
+#endif
+#ifdef CHECK__register_frame_info
+  __register_frame_info (__EH_FRAME_BEGIN__);
+  __deregister_frame_info (__EH_FRAME_BEGIN__);
+#endif
+}
+int __eh_pc;
+__throw () {}
+/* FIXME: this is fragile.  */
+malloc () {}
+strcmp () {}
+strlen () {}
+memcpy () {}
+memset () {}
+free () {}
+abort () {}
+__bzero () {}
+EOF
+dnl No \ in command here because it ends up inside ''.
+if AC_TRY_COMMAND([${CC-cc} $CFLAGS -DCHECK__register_frame_info
+			    -nostdlib -nostartfiles
+			    -o conftest conftest.c -lgcc >&AC_FD_CC]); then
+  libc_cv_gcc_dwarf2_unwind_info=static
+else
+  libc_cv_gcc_dwarf2_unwind_info=no
+fi
+if test $libc_cv_gcc_dwarf2_unwind_info = no; then
+  if AC_TRY_COMMAND([${CC-cc} $CFLAGS -DCHECK__register_frame
+			      -nostdlib -nostartfiles
+			      -o conftest conftest.c -lgcc >&AC_FD_CC]); then
+    libc_cv_gcc_dwarf2_unwind_info=yes
+  else
+    libc_cv_gcc_dwarf2_unwind_info=no
+  fi
+fi
+rm -f conftest*])
+case $libc_cv_gcc_dwarf2_unwind_info in
+yes)
+  AC_DEFINE(HAVE_DWARF2_UNWIND_INFO)
+  ;;
+static)
+  AC_DEFINE(HAVE_DWARF2_UNWIND_INFO)
+  AC_DEFINE(HAVE_DWARF2_UNWIND_INFO_STATIC)
+  ;;
+esac
+
 AC_CACHE_CHECK(for gcc -fno-exceptions, libc_cv_gcc_no_exceptions, [dnl
 cat > conftest.c <<\EOF
 _start () {}