llvm-project

55b58750 - [ubsan][NFCI] Use SanitizerOrdinal instead of SanitizerMask for EmitCheck (exactly one sanitizer is required) (#122511)

[ubsan][NFCI] Use SanitizerOrdinal instead of SanitizerMask for EmitCheck (exactly one sanitizer is required) (#122511) The `Checked` parameter of `CodeGenFunction::EmitCheck` is of type `ArrayRef<std::pair<llvm::Value *, SanitizerMask>>`, which is overly generalized: SanitizerMask can denote that zero or more sanitizers are enabled, but `EmitCheck` requires that exactly one sanitizer is specified in the SanitizerMask (e.g., `SanitizeTrap.has(Checked[i].second)` enforces that). This patch replaces SanitizerMask with SanitizerOrdinal in the `Checked` parameter of `EmitCheck` and code that transitively relies on it. This should not affect the behavior of UBSan, but it has the advantages that: - the code is clearer: it avoids ambiguity in EmitCheck about what to do if multiple bits are set - specifying the wrong number of sanitizers in `Checked[i].second` will be detected as a compile-time error, rather than a runtime assertion failure Suggested by Vitaly in https://github.com/llvm/llvm-project/pull/122392 as an alternative to adding an explicit runtime assertion that the SanitizerMask contains exactly one sanitizer.