For ZSUPER methods with no defined class for the method entry, start the next lookup at the superclass of the origin class of the method owner, instead of the superclass of the method owner.
Fixes [Bug #16942]
This reverts commit 02b216e5a7.
This reverts commit 9b8825b6f9.
I found that combining sweep and move is not safe. I don't think that
we can do compaction concurrently with _anything_ unless there is a read
barrier installed.
Here is a simple example. A class object is freed, and during it's free
step, it tries to remove itself from its parent's subclass list.
However, during the sweep step, the parent class was moved and the
"currently being freed" class didn't have references updated yet. So we
get a segv like this:
```
(lldb) bt
* thread #1, name = 'ruby', stop reason = signal SIGSEGV
* frame #0: 0x0000560763e344cb ruby`rb_st_lookup at st.c:320:43
frame #1: 0x0000560763e344cb ruby`rb_st_lookup(tab=0x2f7469672f6e6f72, key=3809, value=0x0000560765bf2270) at st.c:1010
frame #2: 0x0000560763e8f16a ruby`rb_search_class_path at variable.c:99:9
frame #3: 0x0000560763e8f141 ruby`rb_search_class_path at variable.c:145
frame #4: 0x0000560763e8f141 ruby`rb_search_class_path(klass=94589785585880) at variable.c:191
frame #5: 0x0000560763ec744e ruby`rb_vm_bugreport at vm_dump.c:996:17
frame #6: 0x0000560763f5b958 ruby`rb_bug_for_fatal_signal at error.c:675:5
frame #7: 0x0000560763e27dad ruby`sigsegv(sig=<unavailable>, info=<unavailable>, ctx=<unavailable>) at signal.c:955:5
frame #8: 0x00007f8b891d33c0 libpthread.so.0`___lldb_unnamed_symbol1$$libpthread.so.0 + 1
frame #9: 0x0000560763efa8bb ruby`rb_class_remove_from_super_subclasses(klass=94589790314280) at class.c:93:56
frame #10: 0x0000560763d10cb7 ruby`gc_sweep_step at gc.c:2674:2
frame #11: 0x0000560763d1187b ruby`gc_sweep at gc.c:4540:2
frame #12: 0x0000560763d101f0 ruby`gc_start at gc.c:6797:6
frame #13: 0x0000560763d15153 ruby`rb_gc_compact at gc.c:7479:12
frame #14: 0x0000560763eb4eb8 ruby`vm_exec_core at vm_insnhelper.c:5183:13
frame #15: 0x0000560763ea9bae ruby`rb_vm_exec at vm.c:1953:22
frame #16: 0x0000560763eac08d ruby`rb_yield at vm.c:1132:9
frame #17: 0x0000560763edb4f2 ruby`rb_ary_collect at array.c:3186:9
frame #18: 0x0000560763e9ee15 ruby`vm_call_cfunc_with_frame at vm_insnhelper.c:2575:12
frame #19: 0x0000560763eb2e66 ruby`vm_exec_core at vm_insnhelper.c:4177:11
frame #20: 0x0000560763ea9bae ruby`rb_vm_exec at vm.c:1953:22
frame #21: 0x0000560763eac08d ruby`rb_yield at vm.c:1132:9
frame #22: 0x0000560763edb4f2 ruby`rb_ary_collect at array.c:3186:9
frame #23: 0x0000560763e9ee15 ruby`vm_call_cfunc_with_frame at vm_insnhelper.c:2575:12
frame #24: 0x0000560763eb2e66 ruby`vm_exec_core at vm_insnhelper.c:4177:11
frame #25: 0x0000560763ea9bae ruby`rb_vm_exec at vm.c:1953:22
frame #26: 0x0000560763ceee01 ruby`rb_ec_exec_node(ec=0x0000560765afa530, n=0x0000560765b088e0) at eval.c:296:2
frame #27: 0x0000560763cf3b7b ruby`ruby_run_node(n=0x0000560765b088e0) at eval.c:354:12
frame #28: 0x0000560763cee4a3 ruby`main(argc=<unavailable>, argv=<unavailable>) at main.c:50:9
frame #29: 0x00007f8b88e560b3 libc.so.6`__libc_start_main + 243
frame #30: 0x0000560763cee4ee ruby`_start + 46
(lldb) f 9
frame #9: 0x0000560763efa8bb ruby`rb_class_remove_from_super_subclasses(klass=94589790314280) at class.c:93:56
90
91 *RCLASS_EXT(klass)->parent_subclasses = entry->next;
92 if (entry->next) {
-> 93 RCLASS_EXT(entry->next->klass)->parent_subclasses = RCLASS_EXT(klass)->parent_subclasses;
94 }
95 xfree(entry);
96 }
(lldb) command script import -r misc/lldb_cruby.py
lldb scripts for ruby has been installed.
(lldb) rp entry->next->klass
(struct RMoved) $1 = (flags = 30, destination = 94589792806680, next = 94589784369160)
(lldb)
```
We don't need to resolve symbols when freeing cc tables, so this commit
just changes the id table iterator to look at values rather than keys
and values.
This changeset reduces the generated binary of
vm_call_method_missing_body from 604 bytes to 532 bytes on my machine.
Should reduce GC pressure as well.
CIs are created on-the-fly, which increases GC pressure. However they
include no references to other objects, and those on-the-fly CIs tend to
be short lived. Why not skip allocation of them. In doing so we need
to add a flag denotes the CI object does not reside inside of objspace.
These crashes are due to alignment issues, casting ADJUST to INSN
and then accessing after the end of the ADJUST. These patches
come from Stefan Sperling <stsp@apache.org>, who reported the
issue.
This leads to double requiring "ext/psych/lib/psych/versions.rb" and
".ext/common/psych/versions.rb", which produces doxens of warnings
during `make test-all`.
20200608T123004Z.log.html.gz
```
[15092/20234]
TestRDocOptions#test_init_with_encoding/home/chkbuild/chkbuild/tmp/build/20200608T123004Z/ruby/ext/psych/lib/psych.rb:233: warning: already initialized constant Psych::LIBYAML_VERSION
/home/chkbuild/chkbuild/tmp/build/20200608T123004Z/ruby/.ext/common/psych.rb:233: warning: previous definition of LIBYAML_VERSION was here
/home/chkbuild/chkbuild/tmp/build/20200608T123004Z/ruby/ext/psych/lib/psych.rb:235: warning: already initialized constant Psych::NOT_GIVEN
/home/chkbuild/chkbuild/tmp/build/20200608T123004Z/ruby/.ext/common/psych.rb:235: warning: previous definition of NOT_GIVEN was here
/home/chkbuild/chkbuild/tmp/build/20200608T123004Z/ruby/ext/psych/lib/psych.rb:271: warning: method redefined; discarding old load
/home/chkbuild/chkbuild/tmp/build/20200608T123004Z/ruby/.ext/common/psych.rb:271: warning: previous definition of load was here
...
```
The same issue happened in fiddle.gemspec, and this change applies the
same fix as [fiddle](https://github.com/ruby/fiddle/issues/34).
