Skip vptr when performing object initialization #4490
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The cehck for vptr could be done differently (is this class dynamic and its base class non-dynamic), and if we change the layout (to put the vptr after any base) then this code will break (could add an assertion that the vptr isn't present apart from at the start of the field list if that'd seem worthwhile). There's still later issues with lowering (if this patch causes crashes in lowering, do they result in fuzz failures/need to be avoided before this change is submitted?)
zygoloid
approved these changes
Nov 5, 2024
| for (auto [i, dest_field_id] : llvm::enumerate(dest_elem_fields)) { | ||
| auto dest_field = | ||
| sem_ir.insts().GetAs<SemIR::StructTypeField>(dest_field_id); | ||
| if (dest_field.name_id == SemIR::NameId::Vptr) { | ||
| new_block.Set(i, SemIR::InstId::BuiltinError); |
There was a problem hiding this comment.
Please add a TODO comment here to put a real vtable pointer in the vptr slot.
Comment on lines
+395
to
+399
| bool dest_has_vptr = | ||
| !dest_elem_fields.empty() && | ||
| sem_ir.insts() | ||
| .GetAs<SemIR::StructTypeField>(dest_elem_fields.front()) | ||
| .name_id == SemIR::NameId::Vptr; |
There was a problem hiding this comment.
This might be worth factoring out into a helper function. Let's keep an eye on this and see if we want to do it in more places.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The cehck for vptr could be done differently (is this class dynamic and
its base class non-dynamic), and if we change the layout (to put the
vptr after any base) then this code will break (could add an assertion
that the vptr isn't present apart from at the start of the field list if
that'd seem worthwhile).
There's still later issues with lowering (if this patch causes crashes
in lowering, do they result in fuzz failures/need to be avoided before
this change is submitted?)