#1574: objgroup: fix ubsan error with improper casting #1575
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PhilMiller
reviewed
Oct 7, 2021
src/vt/objgroup/manager.impl.h
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| auto const type_idx = proxy::ObjGroupProxy::getTypeIdx(proxy_bits); | ||
| auto const getter = registry::getObjGetter(type_idx); | ||
| auto ptr = getter(proxy_bits, objs_); | ||
| return static_cast<ObjT*>(ptr); |
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If you're just going to get back void* and static_cast it here, why not type erase at the point of storage, and just just look up the void*? I.e. what purpose does the holder serve now?
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That said, I'm fine with just going with this. The code around this is already horrifically complicated, through use of the registry, so this isn't making it much worse. I don't think this is likely to be catastrophically bad for performance
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I'll approve, you can decide whether you want to merge or take a different approach.
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If you're just going to get back
void*andstatic_castit here, why not type erase at the point of storage, and just just look up thevoid*? I.e. what purpose does the holder serve now?
The holder holds a unique_ptr to the actual object so it can be destroyed properly. If it was stored as a void*, it would not fire the destructor.
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There is another potential solution of using a virtual method in the base holder to get to the void*. Would you prefer that approach?
PhilMiller
approved these changes
Oct 7, 2021
src/vt/objgroup/manager.impl.h
Outdated
| auto const type_idx = proxy::ObjGroupProxy::getTypeIdx(proxy_bits); | ||
| auto const getter = registry::getObjGetter(type_idx); | ||
| auto ptr = getter(proxy_bits, objs_); | ||
| return static_cast<ObjT*>(ptr); |
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I'll approve, you can decide whether you want to merge or take a different approach.
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PR tests (clang-10, ubuntu, mpich) Build for cfdee3e |
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I like this solution more. It's super simple compared to |
jstrzebonski
approved these changes
Oct 7, 2021
Codecov Report
@@ Coverage Diff @@
## develop #1575 +/- ##
===========================================
- Coverage 82.96% 82.90% -0.07%
===========================================
Files 784 784
Lines 29740 29740
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- Hits 24675 24655 -20
- Misses 5065 5085 +20
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Fixes #1574