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| author | bors <bors@rust-lang.org> | 2024-03-08 17:31:00 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2024-03-08 17:31:00 +0000 |
| commit | a655e648a9f94d74263108366b83e677af56e35d (patch) | |
| tree | d429bb05e0093e1b916de108fa0c6df8855bf191 /compiler/rustc_const_eval | |
| parent | 74acabe9b042ea8c42862ee29aca2a8b7d333644 (diff) | |
| parent | 8abeac230af348148f1fd4f20ea6fd1045b941e9 (diff) | |
| download | rust-a655e648a9f94d74263108366b83e677af56e35d.tar.gz rust-a655e648a9f94d74263108366b83e677af56e35d.zip | |
Auto merge of #122190 - matthiaskrgr:rollup-9ol4y30, r=matthiaskrgr
Rollup of 8 pull requests Successful merges: - #121025 (add known-bug tests for derive failure to detect packed repr) - #121194 (Refactor pre-getopts command line argument handling) - #121563 (Use `ControlFlow` in visitors.) - #122173 (Don't ICE in CTFE if raw/fn-ptr types differ) - #122175 (Bless tidy issues order) - #122179 (rustc: Fix typo) - #122181 (Fix crash in internal late lint checking) - #122183 (interpret: update comment about read_discriminant on uninhabited variants) Failed merges: - #122076 (Tweak the way we protect in-place function arguments in interpreters) - #122132 (Diagnostic renaming 3) r? `@ghost` `@rustbot` modify labels: rollup
Diffstat (limited to 'compiler/rustc_const_eval')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/discriminant.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/transform/check_consts/check.rs | 1 |
2 files changed, 7 insertions, 2 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/discriminant.rs b/compiler/rustc_const_eval/src/interpret/discriminant.rs index e951a77611c..6d4f6d0cb3c 100644 --- a/compiler/rustc_const_eval/src/interpret/discriminant.rs +++ b/compiler/rustc_const_eval/src/interpret/discriminant.rs @@ -10,6 +10,8 @@ use super::{ImmTy, InterpCx, InterpResult, Machine, Readable, Scalar, Writeable} impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { /// Writes the discriminant of the given variant. + /// + /// If the variant is uninhabited, this is UB. #[instrument(skip(self), level = "trace")] pub fn write_discriminant( &mut self, @@ -102,6 +104,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { /// Read discriminant, return the runtime value as well as the variant index. /// Can also legally be called on non-enums (e.g. through the discriminant_value intrinsic)! + /// + /// Will never return an uninhabited variant. #[instrument(skip(self), level = "trace")] pub fn read_discriminant( &self, @@ -244,7 +248,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { variant } }; - // For consistency with `write_discriminant`, and to make sure that `project_downcast` cannot fail due to strange layouts, we declare immediate UB for uninhabited variants. + // Reading the discriminant of an uninhabited variant is UB. This is the basis for the + // `uninhabited_enum_branching` MIR pass. It also ensures consistency with + // `write_discriminant`. if op.layout().for_variant(self, index).abi.is_uninhabited() { throw_ub!(UninhabitedEnumVariantRead(index)) } diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index 0b41b4f9682..7ec78e7b9cf 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -581,7 +581,6 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { if is_int_bool_or_char(lhs_ty) && is_int_bool_or_char(rhs_ty) { // Int, bool, and char operations are fine. } else if lhs_ty.is_fn_ptr() || lhs_ty.is_unsafe_ptr() { - assert_eq!(lhs_ty, rhs_ty); assert!(matches!( op, BinOp::Eq |