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| author | Ariel Ben-Yehuda <ariel.byd@gmail.com> | 2017-12-06 02:10:24 +0200 |
|---|---|---|
| committer | Ariel Ben-Yehuda <ariel.byd@gmail.com> | 2017-12-06 02:10:24 +0200 |
| commit | 9d3558725b9110beaa6740e88847e3addc9c2d0d (patch) | |
| tree | dbf060cf29942448dd691776e1b97a4d6a652966 /src | |
| parent | 66c032cb2d5748e36c416e25c75b80f137f3a7fc (diff) | |
| download | rust-9d3558725b9110beaa6740e88847e3addc9c2d0d.tar.gz rust-9d3558725b9110beaa6740e88847e3addc9c2d0d.zip | |
work around weird match arm lifetimes
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc_mir/dataflow/impls/mod.rs | 26 | ||||
| -rw-r--r-- | src/test/run-pass/match-pipe-binding.rs | 1 |
2 files changed, 24 insertions, 3 deletions
diff --git a/src/librustc_mir/dataflow/impls/mod.rs b/src/librustc_mir/dataflow/impls/mod.rs index e7a25c212c3..db8ca0628c4 100644 --- a/src/librustc_mir/dataflow/impls/mod.rs +++ b/src/librustc_mir/dataflow/impls/mod.rs @@ -585,9 +585,29 @@ impl<'a, 'gcx, 'tcx> BitDenotation for EverInitializedLvals<'a, 'gcx, 'tcx> { sets.gen_all(&init_loc_map[location]); match stmt.kind { - mir::StatementKind::StorageDead(local) => { - // End inits for StorageDead, so that an immutable variable can - // be reinitialized on the next iteration of the loop. + mir::StatementKind::StorageDead(local) | + mir::StatementKind::StorageLive(local) => { + // End inits for StorageDead and StorageLive, so that an immutable + // variable can be reinitialized on the next iteration of the loop. + // + // FIXME(#46525): We *need* to do this for StorageLive as well as + // StorageDead, because lifetimes of match bindings with guards are + // weird - i.e. this code + // + // ``` + // fn main() { + // match 0 { + // a | a + // if { println!("a={}", a); false } => {} + // _ => {} + // } + // } + // ``` + // + // runs the guard twice, using the same binding for `a`, and only + // storagedeads after everything ends, so if we don't regard the + // storagelive as killing storage, we would have a multiple assignment + // to immutable data error. if let LookupResult::Exact(mpi) = rev_lookup.find(&mir::Place::Local(local)) { debug!("stmt {:?} at loc {:?} clears the ever initialized status of {:?}", stmt, location, &init_path_map[mpi]); diff --git a/src/test/run-pass/match-pipe-binding.rs b/src/test/run-pass/match-pipe-binding.rs index bda90d3aaec..9592da77a1b 100644 --- a/src/test/run-pass/match-pipe-binding.rs +++ b/src/test/run-pass/match-pipe-binding.rs @@ -8,6 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. +// compile-flags: -Z borrowck=compare fn test1() { // from issue 6338 |