diff options
| -rw-r--r-- | compiler/rustc_hir_typeck/src/expr.rs | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs index 614761c03bd..ba74476c36d 100644 --- a/compiler/rustc_hir_typeck/src/expr.rs +++ b/compiler/rustc_hir_typeck/src/expr.rs @@ -3243,6 +3243,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } fn check_expr_asm(&self, asm: &'tcx hir::InlineAsm<'tcx>) -> Ty<'tcx> { + let mut diverge = asm.options.contains(ast::InlineAsmOptions::NORETURN); + for (op, _op_sp) in asm.operands { match op { hir::InlineAsmOperand::In { expr, .. } => { @@ -3265,15 +3267,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { hir::InlineAsmOperand::Const { .. } | hir::InlineAsmOperand::SymFn { .. } => {} hir::InlineAsmOperand::SymStatic { .. } => {} hir::InlineAsmOperand::Label { block } => { - self.check_block_no_value(block); + let previous_diverges = self.diverges.get(); + + // The label blocks should have unit return value or diverge. + let ty = + self.check_block_with_expected(block, ExpectHasType(self.tcx.types.unit)); + if !ty.is_never() { + self.demand_suptype(block.span, self.tcx.types.unit, ty); + diverge = false; + } + + // We need this to avoid false unreachable warning when a label diverges. + self.diverges.set(previous_diverges); } } } - if asm.options.contains(ast::InlineAsmOptions::NORETURN) { - self.tcx.types.never - } else { - Ty::new_unit(self.tcx) - } + + if diverge { self.tcx.types.never } else { self.tcx.types.unit } } fn check_offset_of( |