Backport cvar clone bug fix for 19379 to 3.2 #7888
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Blocked by #7902 |
When a class with a class variable is cloned we need to also copy the cvar cache table from the original table to the clone. I found this bug while working on fixing [Bug #19379]. While this does not fix that bug directly it is still a required change to fix another bug revealed by the fix in ruby#7265 This needs to be backported to 3.2.x and 3.1.x. Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
The class variable cache that was added in ruby#4544 changed the behavior of class variables on cloned classes. As reported when a class is cloned AND a class variable was set, and the class variable was read from the original class, reading a class variable from the cloned class would return the value from the original class. This was happening because the IC (inline cache) is stored on the ISEQ which is shared between the original and cloned class, therefore they share the cache too. To fix this we are now storing the `cref` in the cache so that we can check if it's equal to the current `cref`. If it's different we don't want to read from the cache. If it's the same we do. Cloned classes don't share the same cref with their original class. This will need to be backported to 3.1 in addition to 3.2 since the bug exists in both versions. We also added a marking function which was missing. Fixes [Bug #19379] Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
We were missing the write barrier for class_value to cref. This should fix the segv we were seeing in http://ci.rvm.jp/logfiles/brlog.trunk-gc-asserts.20230601-165052 Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
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nagachika
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This PR backports #7275 and #7265 to
ruby_3_2. I know this is normally done by the release manager but since there were conflicts I figured it would be helpful to do the backport and open a PR.Fixes: https://bugs.ruby-lang.org/issues/19394