[6.2] Swift SIL: Fix argument conventions for functions which have both, a direct and indirect result. #81865
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Contributor
eeckstein
commented
May 30, 2025
eeckstein
commented
- Explanation: This fixes a mis-compile with functions, which return a tuple where the first tuple element is a direct result and the second tuple element is an indirect result. This lets alias analysis assume that the memory pointed to by the indirect argument cannot be written by the called function.
- Risk: Low. It's a simple fix which corrects the subscript operation of a LazyFilterCollection in the swift compiler sources.
- Testing: Tested by lit tests.
- Issue: rdar://152160748
- Reviewer: @atrick
- Main branch PR: Swift SIL: Fix argument conventions for functions which have both, a direct and indirect result #81806
…direct and indirect result. The function convention for the first argument is not identified as indirect-out. This lets alias analysis assume that the memory pointed to by argument 0 cannot be written by the called function. The problem is that subscripting a LazyFilterCollection (with the base index, e.g. `Int`) does not work as expected, because it returns the nth element of the base collection! The fix is to implement the subscript "manually". Fixes a mis-compile. rdar://152160748
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@swift-ci test |
tbkka
approved these changes
May 30, 2025
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