diff options
| -rw-r--r-- | compiler/rustc_mir_build/src/build/scope.rs | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs index a27c43928eb..7ed493ec9c7 100644 --- a/compiler/rustc_mir_build/src/build/scope.rs +++ b/compiler/rustc_mir_build/src/build/scope.rs @@ -678,6 +678,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // `build_drop_trees` doesn't have access to our source_info, so we // create a dummy terminator now. `TerminatorKind::UnwindResume` is used // because MIR type checking will panic if it hasn't been overwritten. + // (See `<ExitScopes as DropTreeBuilder>::link_entry_point`.) self.cfg.terminate(block, source_info, TerminatorKind::UnwindResume); self.cfg.start_new_block().unit() @@ -710,6 +711,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // `build_drop_trees` doesn't have access to our source_info, so we // create a dummy terminator now. `TerminatorKind::UnwindResume` is used // because MIR type checking will panic if it hasn't been overwritten. + // (See `<ExitScopes as DropTreeBuilder>::link_entry_point`.) self.cfg.terminate(block, source_info, TerminatorKind::UnwindResume); } @@ -1440,7 +1442,15 @@ impl<'tcx> DropTreeBuilder<'tcx> for ExitScopes { cfg.start_new_block() } fn link_entry_point(cfg: &mut CFG<'tcx>, from: BasicBlock, to: BasicBlock) { - cfg.block_data_mut(from).terminator_mut().kind = TerminatorKind::Goto { target: to }; + // There should be an existing terminator with real source info and a + // dummy TerminatorKind. Replace it with a proper goto. + // (The dummy is added by `break_scope` and `break_for_else`.) + let term = cfg.block_data_mut(from).terminator_mut(); + if let TerminatorKind::UnwindResume = term.kind { + term.kind = TerminatorKind::Goto { target: to }; + } else { + span_bug!(term.source_info.span, "unexpected dummy terminator kind: {:?}", term.kind); + } } } |