[analyzer] Fix BuiltingFunctionChecker crash on large types (#174335) #12057
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) Previously, if the result type was 'large' (at least 65 bits), then the ASTContext::getIntTypeForBitwidth would return an empty QualType, causing later a crash when we assume it's non-empty. Instead of using this API, we could piggyback on the BigInt type to formulate a "large enough" type for calculating the mathematically correct result for the operation to check against. Crash: https://godbolt.org/z/dGY3vh39a ```c++ void bigint(_BitInt(63) a, _BitInt(63) b) { _BitInt(63) result = 0; (void)__builtin_add_overflow(a, b, &result); // crashes here } ``` Fixes llvm#173795 rdar://166709144 (cherry picked from commit 984c577)
Author
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@swift-ci please test |
Author
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The linux test failure doesn't seem related. |
ziqingluo-90
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Jan 5, 2026
ziqingluo-90
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ziqingluo-90
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The fix LGTM. I'm curious whether the behavior of ASTContext::getIntTypeForBitwidth is considered correct or not?
Author
Yes. It depends on the contract. It works for the usual types and powers of 2. |
Author
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@swift-ci please test Linux |
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@swift-ci please test macOS |
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Previously, if the result type was 'large' (at least 65 bits), then the ASTContext::getIntTypeForBitwidth would return an empty QualType, causing later a crash when we assume it's non-empty.
Instead of using this API, we could piggyback on the BigInt type to formulate a "large enough" type for calculating the mathematically correct result for the operation to check against. Crash: https://godbolt.org/z/dGY3vh39a
Fixes llvm#173795
rdar://166709144
(cherry picked from commit 984c577)