[6.2] SILGen: Don't copy_addr [take] trivial address-only values. #84267
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This is a new case that comes up with `InlineArray`, since an `InlineArray` with unknown count but known trivial element type is trivial but still address-only due to its unknown size. We are inconsistent about whether we emit formal copies or not of these values; they should generally be unnecessary as long as the memory location of a value is sufficiently long-lived, but the SIL verifier still reasonably considers a `[take]` as an invalidation of the memory, even though at runtime a take is a no-op. Since the take is unnecessary, we can just not take when we copy out of a trivial address location. Fixes swiftlang#84141 | rdar://160007939.
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| @swift-ci Please test |
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| @swift-ci Please test Linux |
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| @swift-ci Please test Linux |
tbkka approved these changes Sep 16, 2025
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Explanation: Fixes an assertion failure when
switch-ing or potentially performing other operations on anInlineArraywith a known-bitwise-copyable type but generic count.Scope: Bug fix.
Issues: #84141, rdar://160007939
Original PR: #84264
Risk: Low. Small change that should have no effect on most existing code.
Testing: Swift CI, test case from bug report
Reviewers: @meg-gupta, @atrick