Expand upon comment regarding self-assignment

2022-11-12 20:05:52 +01:00
parent abe31a9986
commit d66a00a7b1
1 changed files with 1 additions and 1 deletions
--- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
+++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
@@ -317,7 +317,7 @@ struct CollectAndPatch<'tcx, 'map> {

    /// For a given MIR location, this stores the values of the operands used by that location. In
    /// particular, this is before the effect, such that the operands of `_1 = _1 + _2` are
-    /// properly captured.
+    /// properly captured. (This may become UB soon, but it is currently emitted even by safe code.)
    before_effect: FxHashMap<(Location, Place<'tcx>), ScalarTy<'tcx>>,

    /// Stores the assigned values for assignments where the Rvalue is constant.