* GCC EH unwinding bug and libjava calling std::terminate ()
@ 2009-03-27 12:38 Jan Hubicka
2009-03-27 13:11 ` Andrew Haley
0 siblings, 1 reply; 5+ messages in thread
From: Jan Hubicka @ 2009-03-27 12:38 UTC (permalink / raw)
To: gcc, java
Hi,
current mainline is buggy in EH unwinding effectivly ignoring
MUST_NOT_THROW regions when reached via RESX from local handlers.
See http://gcc.gnu.org/ml/gcc-patches/2009-03/msg01285.html for details.
Unfortunately this patch causes bootstrap failure when building libjava,
because std::terminate() is now called. The call comes from
run_proxy in natVMProxy.cc where we have cleanup code calling
destructor of:
_Jv_InterpFrame frame_desc (self->self, thread, proxyClass,
NULL, frame_proxy);
Now the desctuctor is pretty simple but because of:
'if a destructor called during stack unwinding exits with an exception,
std::terminate is called'
and because we use -fnon-call-excpetion and destructor is accessing
memory, we keep MUST_NOT_THROW terminate () call accessible
because after inlining the destructor, cleanup might unwind up
to that MUST_NOT_THROW.
Questio is how to fix this situation? Shall we link with C++ runtime,
or use -fno-non-call-exceptions to build this file or somehow restruture
code to avoid this case?
Honza
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: GCC EH unwinding bug and libjava calling std::terminate ()
2009-03-27 12:38 GCC EH unwinding bug and libjava calling std::terminate () Jan Hubicka
@ 2009-03-27 13:11 ` Andrew Haley
2009-03-27 18:14 ` Jan Hubicka
0 siblings, 1 reply; 5+ messages in thread
From: Andrew Haley @ 2009-03-27 13:11 UTC (permalink / raw)
To: Jan Hubicka; +Cc: gcc, java
Jan Hubicka wrote:
> current mainline is buggy in EH unwinding effectivly ignoring
> MUST_NOT_THROW regions when reached via RESX from local handlers.
> See http://gcc.gnu.org/ml/gcc-patches/2009-03/msg01285.html for details.
>
> Unfortunately this patch causes bootstrap failure when building libjava,
> because std::terminate() is now called. The call comes from
> run_proxy in natVMProxy.cc where we have cleanup code calling
> destructor of:
>
> _Jv_InterpFrame frame_desc (self->self, thread, proxyClass,
> NULL, frame_proxy);
>
> Now the desctuctor is pretty simple but because of:
> 'if a destructor called during stack unwinding exits with an exception,
> std::terminate is called'
>
> and because we use -fnon-call-excpetion and destructor is accessing
> memory, we keep MUST_NOT_THROW terminate () call accessible
> because after inlining the destructor, cleanup might unwind up
> to that MUST_NOT_THROW.
>
> Questio is how to fix this situation? Shall we link with C++ runtime,
Please don't.
> or use -fno-non-call-exceptions
No, because it might segfault, and we need to catch it.
> to build this file or somehow restruture
> code to avoid this case?
/* Gimplify a MUST_NOT_THROW_EXPR. */
static enum gimplify_status
gimplify_must_not_throw_expr (tree *expr_p, gimple_seq *pre_p)
{
tree stmt = *expr_p;
tree temp = voidify_wrapper_expr (stmt, NULL);
tree body = TREE_OPERAND (stmt, 0);
tree termination;
if (pragma_java_exceptions)
termination = terminate_node;
else
termination = abort_node;
stmt = build_gimple_eh_filter_tree (body, NULL_TREE,
build_call_n (termination, 0));
Andrew.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: GCC EH unwinding bug and libjava calling std::terminate ()
2009-03-27 13:11 ` Andrew Haley
@ 2009-03-27 18:14 ` Jan Hubicka
2009-03-27 18:21 ` Andrew Haley
0 siblings, 1 reply; 5+ messages in thread
From: Jan Hubicka @ 2009-03-27 18:14 UTC (permalink / raw)
To: Andrew Haley; +Cc: Jan Hubicka, gcc, java
> Jan Hubicka wrote:
>
> > current mainline is buggy in EH unwinding effectivly ignoring
> > MUST_NOT_THROW regions when reached via RESX from local handlers.
> > See http://gcc.gnu.org/ml/gcc-patches/2009-03/msg01285.html for details.
> >
> > Unfortunately this patch causes bootstrap failure when building libjava,
> > because std::terminate() is now called. The call comes from
> > run_proxy in natVMProxy.cc where we have cleanup code calling
> > destructor of:
> >
> > _Jv_InterpFrame frame_desc (self->self, thread, proxyClass,
> > NULL, frame_proxy);
> >
> > Now the desctuctor is pretty simple but because of:
> > 'if a destructor called during stack unwinding exits with an exception,
> > std::terminate is called'
> >
> > and because we use -fnon-call-excpetion and destructor is accessing
> > memory, we keep MUST_NOT_THROW terminate () call accessible
> > because after inlining the destructor, cleanup might unwind up
> > to that MUST_NOT_THROW.
> >
> > Questio is how to fix this situation? Shall we link with C++ runtime,
>
> Please don't.
>
> > or use -fno-non-call-exceptions
>
> No, because it might segfault, and we need to catch it.
>
> > to build this file or somehow restruture
> > code to avoid this case?
>
> /* Gimplify a MUST_NOT_THROW_EXPR. */
>
> static enum gimplify_status
> gimplify_must_not_throw_expr (tree *expr_p, gimple_seq *pre_p)
> {
> tree stmt = *expr_p;
> tree temp = voidify_wrapper_expr (stmt, NULL);
> tree body = TREE_OPERAND (stmt, 0);
> tree termination;
>
> if (pragma_java_exceptions)
> termination = terminate_node;
> else
> termination = abort_node;
OK, pragma_java_exceptions variable is not there, does something like
this work for you?
I would like to commit this to mainline so the MUST_NOT_THROW fix can go
as well. I am commiting it to pretty-ipa in meantime.
Honza
Index: cp/except.c
===================================================================
*** cp/except.c (revision 145101)
--- cp/except.c (working copy)
*************** choose_personality_routine (enum languag
*** 353,358 ****
--- 353,359 ----
case lang_java:
state = chose_java;
+ terminate_node = built_in_decls [BUILT_IN_ABORT];
eh_personality_libfunc = init_one_libfunc (USING_SJLJ_EXCEPTIONS
? "__gcj_personality_sj0"
: "__gcj_personality_v0");
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: GCC EH unwinding bug and libjava calling std::terminate ()
2009-03-27 18:14 ` Jan Hubicka
@ 2009-03-27 18:21 ` Andrew Haley
2009-03-27 18:25 ` Jan Hubicka
0 siblings, 1 reply; 5+ messages in thread
From: Andrew Haley @ 2009-03-27 18:21 UTC (permalink / raw)
To: Jan Hubicka; +Cc: gcc, java
Jan Hubicka wrote:
> OK, pragma_java_exceptions variable is not there
It's in mainline now.
> does something like this work for you?
Yes.
Andrew.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: GCC EH unwinding bug and libjava calling std::terminate ()
2009-03-27 18:21 ` Andrew Haley
@ 2009-03-27 18:25 ` Jan Hubicka
0 siblings, 0 replies; 5+ messages in thread
From: Jan Hubicka @ 2009-03-27 18:25 UTC (permalink / raw)
To: Andrew Haley; +Cc: Jan Hubicka, gcc, java
> Jan Hubicka wrote:
>
> > OK, pragma_java_exceptions variable is not there
>
> It's in mainline now.
>
> > does something like this work for you?
>
> Yes.
OK, I will do full testing cycle (x86_64-linux) and commit it.
Thanks!
Honza
>
> Andrew.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2009-03-27 12:38 GCC EH unwinding bug and libjava calling std::terminate () Jan Hubicka
2009-03-27 13:11 ` Andrew Haley
2009-03-27 18:14 ` Jan Hubicka
2009-03-27 18:21 ` Andrew Haley
2009-03-27 18:25 ` Jan Hubicka
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