llvm: fix lowering of runtime refs to comptime-only decls#13166
Merged
andrewrk merged 1 commit intoziglang:masterfrom Oct 15, 2022
Merged
llvm: fix lowering of runtime refs to comptime-only decls#13166andrewrk merged 1 commit intoziglang:masterfrom
andrewrk merged 1 commit intoziglang:masterfrom
Conversation
When we want a runtime pointer to a zero-bit value we use an undef pointer, but what if we want a runtime pointer to a comptime-only value? Normally, if `T` is a comptime-only type such as `*const comptime_int`, then `*const T` would also be a comptime-only type, so anything referencing a comptime-only value is usually also comptime-only, and therefore not emitted to the executable. However, what if instead we have a `*const anyopaque` pointing to a comptime-only value? Certainly, `*const anyopaque` is a runtime type, and so we need some runtime value to store, even when it happens to be pointing to a comptime-only value. In this case we want to do the same thing as we do when pointing to a zero-bit value, so we use `hasRuntimeBits` to handle both cases instead of ignoring comptime. Closes ziglang#12025
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
When we want a runtime pointer to a zero-bit value we use an undef pointer, but what if we want a runtime pointer to a comptime-only value? Normally, if
Tis a comptime-only type such as*const comptime_int, then*const Twould also be a comptime-only type, so anything referencing a comptime-only value is usually also comptime-only, and therefore not emitted to the executable.However, what if instead we have a
*const anyopaquepointing to a comptime-only value? Certainly,*const anyopaqueis a runtime type, and so we need some runtime value to store, even when it happens to be pointing to a comptime-only value. In this case we want to do the same thing as we do when pointing to a zero-bit value, so we usehasRuntimeBitsto handle both cases instead of ignoring comptime.Closes #12025