Richard Stallman has given permission to include code derived from GNU
C Library in libgcc for AIX using the GCC Runtime Exception license.
The updated patch is appended. The GNU C Library code (cxa_atexit.c,
cxa_finalize.c, exit.h) is modified, so I am not exactly certain if my
reference to the GNU C Library origin is correct.
This has been bootstrapped on powerpc-ibm-aix7.1.0.0 using --enable-cxa_atexit.
Any comments, especially about the header for the files derived from
GNU C Library?
Thanks, David
libgcc/
* config.host (powerpc-ibm-aix[56789]): Add t-aix-cxa to tmake_file.
Add crtcxa to extra_parts.
* config/rs6000/exit.h: New file.
* config/rs6000/cxa_atexit.c: New file.
* config/rs6000/cxa_finalize.c: New file.
* config/rs6000/crtcxa.c: New file.
* config/rs6000/t-aix-cxa: New file.
* config/rs6000/libgcc-aix-cxa.ver: New file.
gcc/
* config/rs6000/aix61.h (STARTFILE_SPEC): Add crtcxa.
Index: libgcc/config.host
===================================================================
--- libgcc/config.host (revision 195639)
+++ libgcc/config.host (working copy)
@@ -899,7 +899,8 @@
;;
rs6000-ibm-aix[56789].* | powerpc-ibm-aix[56789].*)
md_unwind_header=rs6000/aix-unwind.h
- tmake_file="t-fdpbit rs6000/t-ppc64-fp rs6000/t-slibgcc-aix
rs6000/t-ibm-ldouble"
+ tmake_file="t-fdpbit rs6000/t-ppc64-fp rs6000/t-slibgcc-aix
rs6000/t-ibm-ldouble rs6000/t-aix-cxa"
+ extra_parts="crtcxa.o crtcxa_s.o"
;;
rl78-*-elf)
tmake_file="$tm_file t-fdpbit rl78/t-rl78"
Index: libgcc/config/rs6000/exit.h
===================================================================
--- libgcc/config/rs6000/exit.h (revision 0)
+++ libgcc/config/rs6000/exit.h (revision 0)
@@ -0,0 +1,92 @@
+/* Copyright (C) 1991-2013 Free Software Foundation, Inc.
+
+Derived from exit.h in GNU C Library.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+#ifndef _EXIT_H
+#define _EXIT_H 1
+
+#define attribute_hidden
+#define INTDEF(name)
+
+#include <stdbool.h>
+#include <stdint.h>
+
+enum
+{
+ ef_free, /* `ef_free' MUST be zero! */
+ ef_us,
+ ef_on,
+ ef_at,
+ ef_cxa
+};
+
+struct exit_function
+ {
+ /* `flavour' should be of type of the `enum' above but since we need
+ this element in an atomic operation we have to use `long int'. */
+ long int flavor;
+ union
+ {
+ void (*at) (void);
+ struct
+ {
+ void (*fn) (int status, void *arg);
+ void *arg;
+ } on;
+ struct
+ {
+ void (*fn) (void *arg, int status);
+ void *arg;
+ void *dso_handle;
+ } cxa;
+ } func;
+ };
+struct exit_function_list
+ {
+ struct exit_function_list *next;
+ size_t idx;
+ struct exit_function fns[32];
+ };
+extern struct exit_function_list *__exit_funcs attribute_hidden;
+extern struct exit_function_list *__quick_exit_funcs attribute_hidden;
+
+extern struct exit_function *__new_exitfn (struct exit_function_list **listp);
+extern uint64_t __new_exitfn_called attribute_hidden;
+
+extern void __run_exit_handlers (int status, struct exit_function_list **listp,
+ bool run_list_atexit)
+ attribute_hidden __attribute__ ((__noreturn__));
+
+extern int __internal_atexit (void (*func) (void *), void *arg, void *d,
+ struct exit_function_list **listp)
+ attribute_hidden;
+extern int __cxa_at_quick_exit (void (*func) (void *), void *d);
+
+extern int __cxa_atexit (void (*func) (void *), void *arg, void *d);
+extern int __cxa_atexit_internal (void (*func) (void *), void *arg, void *d)
+ attribute_hidden;
+
+extern void __cxa_finalize (void *d);
+
+#endif /* exit.h */
Index: libgcc/config/rs6000/cxa_atexit.c
===================================================================
--- libgcc/config/rs6000/cxa_atexit.c (revision 0)
+++ libgcc/config/rs6000/cxa_atexit.c (revision 0)
@@ -0,0 +1,130 @@
+/* Copyright (C) 1999-2013 Free Software Foundation, Inc.
+
+Derived from cxa_atexit.c in GNU C Library.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "exit.h"
+
+#undef __cxa_atexit
+
+#define atomic_write_barrier() __asm__ ("eieio" ::: "memory")
+
+int
+attribute_hidden
+__internal_atexit (void (*func) (void *), void *arg, void *d,
+ struct exit_function_list **listp)
+{
+ struct exit_function *new = __new_exitfn (listp);
+
+ if (new == NULL)
+ return -1;
+
+#ifdef PTR_MANGLE
+ PTR_MANGLE (func);
+#endif
+ new->func.cxa.fn = (void (*) (void *, int)) func;
+ new->func.cxa.arg = arg;
+ new->func.cxa.dso_handle = d;
+ atomic_write_barrier ();
+ new->flavor = ef_cxa;
+ return 0;
+}
+
+
+/* Register a function to be called by exit or when a shared library
+ is unloaded. This function is only called from code generated by
+ the C++ compiler. */
+int
+__cxa_atexit (void (*func) (void *), void *arg, void *d)
+{
+ return __internal_atexit (func, arg, d, &__exit_funcs);
+}
+INTDEF(__cxa_atexit)
+
+
+static struct exit_function_list initial;
+struct exit_function_list *__exit_funcs = &initial;
+uint64_t __new_exitfn_called;
+
+struct exit_function *
+__new_exitfn (struct exit_function_list **listp)
+{
+ struct exit_function_list *p = NULL;
+ struct exit_function_list *l;
+ struct exit_function *r = NULL;
+ size_t i = 0;
+
+ for (l = *listp; l != NULL; p = l, l = l->next)
+ {
+ for (i = l->idx; i > 0; --i)
+ if (l->fns[i - 1].flavor != ef_free)
+ break;
+
+ if (i > 0)
+ break;
+
+ /* This block is completely unused. */
+ l->idx = 0;
+ }
+
+ if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0]))
+ {
+ /* The last entry in a block is used. Use the first entry in
+ the previous block if it exists. Otherwise create a new one. */
+ if (p == NULL)
+ {
+ assert (l != NULL);
+ p = (struct exit_function_list *)
+ calloc (1, sizeof (struct exit_function_list));
+ if (p != NULL)
+ {
+ p->next = *listp;
+ *listp = p;
+ }
+ }
+
+ if (p != NULL)
+ {
+ r = &p->fns[0];
+ p->idx = 1;
+ }
+ }
+ else
+ {
+ /* There is more room in the block. */
+ r = &l->fns[i];
+ l->idx = i + 1;
+ }
+
+ /* Mark entry as used, but we don't know the flavor now. */
+ if (r != NULL)
+ {
+ r->flavor = ef_us;
+ ++__new_exitfn_called;
+ }
+
+ return r;
+}
Index: libgcc/config/rs6000/t-aix-cxa
===================================================================
--- libgcc/config/rs6000/t-aix-cxa (revision 0)
+++ libgcc/config/rs6000/t-aix-cxa (revision 0)
@@ -0,0 +1,10 @@
+LIB2ADDEH += $(srcdir)/config/rs6000/cxa_atexit.c \
+ $(srcdir)/config/rs6000/cxa_finalize.c
+
+SHLIB_MAPFILES += $(srcdir)/config/rs6000/libgcc-aix-cxa.ver
+
+crtcxa.o: $(srcdir)/config/rs6000/crtcxa.c
+ $(crt_compile) -c $<
+
+crtcxa_s.o: $(srcdir)/config/rs6000/crtcxa.c
+ $(crt_compile) -DSHARED -c $<
Index: libgcc/config/rs6000/crtcxa.c
===================================================================
--- libgcc/config/rs6000/crtcxa.c (revision 0)
+++ libgcc/config/rs6000/crtcxa.c (revision 0)
@@ -0,0 +1,42 @@
+/* __dso_handle initialization for AIX.
+ Copyright (C) 2013 Free Software Foundation, Inc.
+ Contributed by David Edelsohn (edels...@gnu.org).
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+#ifdef SHARED
+void *__dso_handle = &__dso_handle;
+#else
+void *__dso_handle = 0;
+#endif
+
+extern void __cxa_finalize (void *);
+
+/* Add __cxa_finalize call to beginning of destructors list. */
+void __init_aix_libgcc_cxa_atexit (void) __attribute__ ((destructor (65535)));
+
+void
+__init_aix_libgcc_cxa_atexit (void)
+{
+ __cxa_finalize (__dso_handle);
+}
+
Index: libgcc/config/rs6000/libgcc-aix-cxa.ver
===================================================================
--- libgcc/config/rs6000/libgcc-aix-cxa.ver (revision 0)
+++ libgcc/config/rs6000/libgcc-aix-cxa.ver (revision 0)
@@ -0,0 +1,4 @@
+GCC_4.8 {
+ __cxa_atexit
+ __cxa_finalize
+}
Index: libgcc/config/rs6000/cxa_finalize.c
===================================================================
--- libgcc/config/rs6000/cxa_finalize.c (revision 0)
+++ libgcc/config/rs6000/cxa_finalize.c (revision 0)
@@ -0,0 +1,84 @@
+/* Copyright (C) 1999-2013 Free Software Foundation, Inc.
+
+Derived from cxa_finalize.c in GNU C Library.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+#include <stdlib.h>
+#include "exit.h"
+
+
+static boolean_t
+catomic_compare_and_exchange_bool_acq (long *mem, long newval, long oldval)
+{
+ return __atomic_compare_exchange (mem, &oldval, &newval, 0,
+ __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
+}
+
+/* If D is non-NULL, call all functions registered with `__cxa_atexit'
+ with the same dso handle. Otherwise, if D is NULL, call all of the
+ registered handlers. */
+void
+__cxa_finalize (void *d)
+{
+ struct exit_function_list *funcs;
+
+ restart:
+ for (funcs = __exit_funcs; funcs; funcs = funcs->next)
+ {
+ struct exit_function *f;
+
+ for (f = &funcs->fns[funcs->idx - 1]; f >= &funcs->fns[0]; --f)
+ {
+ void (*cxafn) (void *arg, int status);
+ void *cxaarg;
+
+ if ((d == NULL || d == f->func.cxa.dso_handle)
+ /* We don't want to run this cleanup more than once. */
+ && (cxafn = f->func.cxa.fn,
+ cxaarg = f->func.cxa.arg,
+ ! catomic_compare_and_exchange_bool_acq (&f->flavor, ef_free,
+ ef_cxa)))
+ {
+ uint64_t check = __new_exitfn_called;
+
+#ifdef PTR_DEMANGLE
+ PTR_DEMANGLE (cxafn);
+#endif
+ cxafn (cxaarg, 0);
+
+ /* It is possible that that last exit function registered
+ more exit functions. Start the loop over. */
+ if (__builtin_expect (check != __new_exitfn_called, 0))
+ goto restart;
+ }
+ }
+ }
+
+ /* Remove the registered fork handlers. We do not have to
+ unregister anything if the program is going to terminate anyway. */
+#ifdef UNREGISTER_ATFORK
+ if (d != NULL)
+ UNREGISTER_ATFORK (d);
+#endif
+}
Index: gcc/config/rs6000/aix61.h
===================================================================
--- gcc/config/rs6000/aix61.h (revision 195639)
+++ gcc/config/rs6000/aix61.h (working copy)
@@ -163,7 +163,8 @@
%{maix64:%{pg:gcrt0_64%O%s}%{!pg:%{p:mcrt0_64%O%s}%{!p:crt0_64%O%s}}}\
%{!maix64:\
%{pthread:%{pg:gcrt0_r%O%s}%{!pg:%{p:mcrt0_r%O%s}%{!p:crt0_r%O%s}}}\
- %{!pthread:%{pg:gcrt0%O%s}%{!pg:%{p:mcrt0%O%s}%{!p:crt0%O%s}}}}}"
+ %{!pthread:%{pg:gcrt0%O%s}%{!pg:%{p:mcrt0%O%s}%{!p:crt0%O%s}}}}}\
+ %{shared:crtcxa_s%O%s;:crtcxa%O%s}"
/* AIX V5 typedefs ptrdiff_t as "long" while earlier releases used "int". */
