Issue #9961 has been updated by Koichi Sasada.
Status changed from Open to Closed
% Done changed from 0 to 100
Applied in changeset r46465.
- vm.c (rb_vm_rewind_cfp): add new function to rewind specified cfp
with invoking RUBY_EVENT_C_RETURN.
[Bug #9961] - vm_core.h: ditto.
- eval.c (rb_protect): use it.
- eval.c (rb_rescue2): ditto.
- vm_eval.c (rb_iterate): ditto.
- test/ruby/test_settracefunc.rb: add a test.
- vm_core.h (rb_name_err_mesg_new):
Bug #9961: TracePoint can skip c_return with rb_rescue()
- Author: Koichi Sasada
- Status: Closed
- Priority: Normal
- Assignee: Koichi Sasada
- Category: core
- Target version: current: 2.2.0
- ruby -v: 2.2
- Backport: 2.0.0: REQUIRED, 2.1: REQUIRED
下記のようなテストに失敗します。
def test_rb_rescue
events = []
curr_thread = Thread.current
TracePoint.new(:a_call, :a_return){|tp|
next if curr_thread != Thread.current
events << [tp.event, tp.method_id]
}.enable do
begin
-Numeric.new
rescue => e
# ignore
end
end
assert_equal [
[:b_call, :test_rb_rescue],
[:c_call, :new],
[:c_call, :initialize],
[:c_return, :initialize],
[:c_return, :new],
[:c_call, :-@],
[:c_call, :coerce],
[:c_call, :to_s],
[:c_return, :to_s],
[:c_call, :new],
[:c_call, :initialize],
[:c_return, :initialize],
[:c_return, :new],
[:c_call, :exception],
[:c_return, :exception],
[:c_call, :backtrace],
[:c_return, :backtrace],
[:c_return, :coerce], # don't miss it!
[:c_call, :to_s],
[:c_return, :to_s],
[:c_call, :to_s],
[:c_return, :to_s],
[:c_call, :new],
[:c_call, :initialize],
[:c_return, :initialize],
[:c_return, :new],
[:c_call, :exception],
[:c_return, :exception],
[:c_call, :backtrace],
[:c_return, :backtrace],
[:c_return, :-@],
[:c_call, :===],
[:c_return, :===],
[:b_return, :test_rb_rescue]], events
end
何が起きているかというと、
(1) -Numeric.new で rb_rescue() の後で rb_funcall() した先で例外が起こる
(2) rb_rescue() では、c_return を無視して cfp を切り詰める
ということにより、c_return がスキップしてしまう、という現象となりました。
次のパッチで解決します。
Index: eval.c
===================================================================
--- eval.c (revision 46464)
+++ eval.c (working copy)
@@ -803,7 +803,7 @@ rb_rescue2(VALUE (* b_proc) (ANYARGS), V
}
}
else {
- th->cfp = cfp; /* restore */
+ rb_vm_rewind_cfp(th, cfp);
if (state == TAG_RAISE) {
int handle = FALSE;
@@ -862,7 +862,7 @@ rb_protect(VALUE (* proc) (VALUE), VALUE
SAVE_ROOT_JMPBUF(th, result = (*proc) (data));
}
else {
- th->cfp = cfp;
+ rb_vm_rewind_cfp(th, cfp);
}
MEMCPY(&(th)->root_jmpbuf, &org_jmpbuf, rb_jmpbuf_t, 1);
th->protect_tag = protect_tag.prev;
Index: vm.c
===================================================================
--- vm.c (revision 46464)
+++ vm.c (working copy)
@@ -288,6 +288,23 @@ rb_vm_pop_cfunc_frame(void)
vm_pop_frame(th);
}
+void
+rb_vm_rewind_cfp(rb_thread_t *th, rb_control_frame_t *cfp)
+{
+ /* check skipped frame */
+ while (th->cfp != cfp) {
+#if VMDEBUG
+ printf("skipped frame: %s\n", vm_frametype_name(th->cfp));
+#endif
+ if (VM_FRAME_TYPE(th->cfp) != VM_FRAME_MAGIC_CFUNC) {
+ vm_pop_frame(th);
+ }
+ else { /* unlikely path */
+ rb_vm_pop_cfunc_frame();
+ }
+ }
+}
+
/* obsolete */
void
rb_frame_pop(void)
Index: vm_core.h
===================================================================
--- vm_core.h (revision 46464)
+++ vm_core.h (working copy)
@@ -901,6 +901,7 @@ VALUE rb_name_err_mesg_new(VALUE obj, VA
void rb_vm_stack_to_heap(rb_thread_t *th);
void ruby_thread_init_stack(rb_thread_t *th);
int rb_vm_control_frame_id_and_class(const rb_control_frame_t *cfp, ID
*idp, VALUE *klassp);
+void rb_vm_rewind_cfp(rb_thread_t *th, rb_control_frame_t *cfp);
void rb_gc_mark_machine_stack(rb_thread_t *th);
Index: vm_eval.c
===================================================================
--- vm_eval.c (revision 46464)
+++ vm_eval.c (working copy)
@@ -1093,18 +1093,7 @@ rb_iterate(VALUE (* it_proc) (VALUE), VA
th->errinfo = Qnil;
retval = GET_THROWOBJ_VAL(err);
- /* check skipped frame */
- while (th->cfp != cfp) {
-#if VMDEBUG
- printf("skipped frame: %s\n", vm_frametype_name(th->cfp));
-#endif
- if (VM_FRAME_TYPE(th->cfp) != VM_FRAME_MAGIC_CFUNC) {
- vm_pop_frame(th);
- }
- else { /* unlikely path */
- rb_vm_pop_cfunc_frame();
- }
- }
+ rb_vm_rewind_cfp(th, cfp);
}
else{
/* SDR(); printf("%p, %p\n", cdfp, escape_dfp); */
例によって、2.1, 2.0 でもおきます。
（Numeric.new なんてできるとは知らなかった）