From f49126e3d612ec5f7e571a7ccfb3e4447cfa427c Mon Sep 17 00:00:00 2001 From: Jakob Degen Date: Sun, 8 Jan 2023 18:23:13 -0800 Subject: Document wf constraints on control flow in cleanup blocks Also fixes a bug in dominator computation --- compiler/rustc_data_structures/src/graph/dominators/mod.rs | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'compiler/rustc_data_structures/src') diff --git a/compiler/rustc_data_structures/src/graph/dominators/mod.rs b/compiler/rustc_data_structures/src/graph/dominators/mod.rs index ea2a4388b92..07b1ace2189 100644 --- a/compiler/rustc_data_structures/src/graph/dominators/mod.rs +++ b/compiler/rustc_data_structures/src/graph/dominators/mod.rs @@ -135,7 +135,10 @@ pub fn dominators(graph: G) -> Dominators { // This loop computes the semi[w] for w. semi[w] = w; for v in graph.predecessors(pre_order_to_real[w]) { - let v = real_to_pre_order[v].unwrap(); + // Reachable vertices may have unreachable predecessors, so ignore any of them + let Some(v) = real_to_pre_order[v] else { + continue + }; // eval returns a vertex x from which semi[x] is minimum among // vertices semi[v] +> x *> v. -- cgit 1.4.1-3-g733a5