[src/trunk]: src/lib/csu/common_elf Add support for invoking GNU C++ local de...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/af5b6c04a946
branches:  trunk
changeset: 519937:af5b6c04a946
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Mon Dec 31 00:40:11 2001 +0000

description:
Add support for invoking GNU C++ local destructors in shared objects
via the __cxa_finalize() mechanism.

XXX Only enabled for new-toolchain platforms, as it requires the assembler
to support the .hidden pseudo-op.

diffstat:

 lib/csu/common_elf/Makefile.inc |  10 +++++++++-
 lib/csu/common_elf/crtbegin.c   |  33 ++++++++++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 4 deletions(-)

diffs (83 lines):

diff -r 25175a98d3d4 -r af5b6c04a946 lib/csu/common_elf/Makefile.inc
--- a/lib/csu/common_elf/Makefile.inc   Mon Dec 31 00:35:21 2001 +0000
+++ b/lib/csu/common_elf/Makefile.inc   Mon Dec 31 00:40:11 2001 +0000
@@ -1,4 +1,6 @@
-#      $NetBSD: Makefile.inc,v 1.12 2001/12/31 00:11:13 thorpej Exp $
+#      $NetBSD: Makefile.inc,v 1.13 2001/12/31 00:40:11 thorpej Exp $
+
+.include <bsd.own.mk>
 
 .if !defined(ELFSIZE)
 ELFSIZE=32
@@ -13,6 +15,12 @@
 CPPFLAGS+=     -DDWARF2_EH
 CPPFLAGS+=     -DJCR
 
+# XXX Temporary until all ELF ports use the new toolchain.  The old
+# toolchain doesn't have support for "hidden" symbols.
+.if defined(USE_NEW_TOOLCHAIN)
+CPPFLAGS+=     -DDSO_HANDLE
+.endif
+
 .if !defined(MACHINE_ARCH) || ${MACHINE_ARCH} != "m68000"
 COPTS+=                -fPIC
 .endif
diff -r 25175a98d3d4 -r af5b6c04a946 lib/csu/common_elf/crtbegin.c
--- a/lib/csu/common_elf/crtbegin.c     Mon Dec 31 00:35:21 2001 +0000
+++ b/lib/csu/common_elf/crtbegin.c     Mon Dec 31 00:40:11 2001 +0000
@@ -1,11 +1,11 @@
-/*     $NetBSD: crtbegin.c,v 1.16 2001/12/30 23:45:01 thorpej Exp $    */
+/*     $NetBSD: crtbegin.c,v 1.17 2001/12/31 00:40:11 thorpej Exp $    */
 
 /*-
- * Copyright (c) 1998 The NetBSD Foundation, Inc.
+ * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
- * by Paul Kranenburg and Ross Harvey.
+ * by Paul Kranenburg, Ross Harvey, and Jason R. Thorpe.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -75,6 +75,25 @@
     __attribute__((section(".jcr"))) = { };
 #endif
 
+#if defined(DSO_HANDLE) && defined(__GNUC__)
+/*
+ * The __dso_handle variable is used to hang C++ local destructors off
+ * of.  In the main program (i.e. using crtbegin.o), the value is 0.
+ * In shared objects (i.e. using crtbeginS.o), the value must be unique.
+ * The symbol is hidden, but the dynamic linker will still relocate it.
+ */
+#ifdef SHARED
+void   *__dso_handle = &__dso_handle;
+#else
+void   *__dso_handle = NULL;
+#endif
+__asm(".hidden __dso_handle");
+
+#ifdef SHARED
+extern void __cxa_finalize(void *) __attribute__((weak));
+#endif
+#endif
+
 static void __dtors(void);
 static void __ctors(void);
 
@@ -149,6 +168,14 @@
 _fini()
 {
 
+#if defined(DSO_HANDLE) && defined(__GNUC__) && defined(SHARED)
+       /*
+        * Call local destructors.
+        */
+       if (__cxa_finalize != NULL)
+               __cxa_finalize(__dso_handle);
+#endif /* DSO_HANDLE && __GNUC__ && SHARED */
+
        /*
         * Call global destructors.
         */