Fix size of type_id in Object.set_crystal_type_id
#13338
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straight-shoota
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kind:bug
HertzDevil
approved these changes
Apr 18, 2023
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The type of
crystal_type_idisInt32, notLibC::SizeT. On 64-bit systems this wrong size would write a 64-bit integer into a space that's only suppose to be 32-bit wide.This bug has limited practical effect. Due to byte ordering the memory representation of 32-bit and small 64-bit values are (usually) identical. The type id is never wider than 32-bits so this works correctly. The only negative side effect would be overriding the first 4 bytes of the object data that follows the type id.
This method is only called from
WeakRef.allocateon an empty object where this is irrelevant.It's sill a bug and needs to be fixed. For the fix I opted to infer the type based on the type of
crystal_instance_type_id(which is a compiler primitive). The size does not need to be hard-coded into stdlib.