diff options
| -rw-r--r-- | src/librustc_typeck/check/compare_method.rs | 2 | ||||
| -rw-r--r-- | src/librustc_typeck/check/mod.rs | 30 | ||||
| -rw-r--r-- | src/librustc_typeck/check/wfcheck.rs | 2 | ||||
| -rw-r--r-- | src/librustc_typeck/diagnostics.rs | 27 | ||||
| -rw-r--r-- | src/test/compile-fail/E0572.rs | 13 |
5 files changed, 59 insertions, 15 deletions
diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs index e85dac1a44c..478de167317 100644 --- a/src/librustc_typeck/check/compare_method.rs +++ b/src/librustc_typeck/check/compare_method.rs @@ -376,7 +376,7 @@ fn compare_predicate_entailment<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>, &infcx.parameter_environment.caller_bounds); infcx.resolve_regions_and_report_errors(&free_regions, impl_m_body_id); } else { - let fcx = FnCtxt::new(&inh, tcx.types.err, impl_m_body_id); + let fcx = FnCtxt::new(&inh, Some(tcx.types.err), impl_m_body_id); fcx.regionck_item(impl_m_body_id, impl_m_span, &[]); } diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 1b35081d524..9c8d7caefe5 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -451,7 +451,7 @@ pub struct FnCtxt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> { // expects the types within the function to be consistent. err_count_on_creation: usize, - ret_ty: Ty<'tcx>, + ret_ty: Option<Ty<'tcx>>, ps: RefCell<UnsafetyState>, @@ -785,12 +785,14 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>, // Create the function context. This is either derived from scratch or, // in the case of function expressions, based on the outer context. - let mut fcx = FnCtxt::new(inherited, fn_sig.output(), body.id); + let mut fcx = FnCtxt::new(inherited, None, body.id); + let ret_ty = fn_sig.output(); *fcx.ps.borrow_mut() = UnsafetyState::function(unsafety, unsafety_id); - fcx.require_type_is_sized(fcx.ret_ty, decl.output.span(), traits::ReturnType); - fcx.ret_ty = fcx.instantiate_anon_types(&fcx.ret_ty); - fn_sig = fcx.tcx.mk_fn_sig(fn_sig.inputs().iter().cloned(), &fcx.ret_ty, fn_sig.variadic); + fcx.require_type_is_sized(ret_ty, decl.output.span(), traits::ReturnType); + fcx.ret_ty = fcx.instantiate_anon_types(&Some(ret_ty)); + fn_sig = fcx.tcx.mk_fn_sig(fn_sig.inputs().iter().cloned(), &fcx.ret_ty.unwrap(), + fn_sig.variadic); { let mut visit = GatherLocalsVisitor { fcx: &fcx, }; @@ -821,7 +823,7 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>, inherited.tables.borrow_mut().liberated_fn_sigs.insert(fn_id, fn_sig); - fcx.check_expr_coercable_to_type(body, fcx.ret_ty); + fcx.check_expr_coercable_to_type(body, fcx.ret_ty.unwrap()); fcx } @@ -1245,7 +1247,7 @@ fn check_const_with_type<'a, 'tcx>(ccx: &'a CrateCtxt<'a, 'tcx>, expected_type: Ty<'tcx>, id: ast::NodeId) { ccx.inherited(id).enter(|inh| { - let fcx = FnCtxt::new(&inh, expected_type, expr.id); + let fcx = FnCtxt::new(&inh, None, expr.id); fcx.require_type_is_sized(expected_type, expr.span, traits::ConstSized); // Gather locals in statics (because of block expressions). @@ -1530,7 +1532,7 @@ enum TupleArgumentsFlag { impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { pub fn new(inh: &'a Inherited<'a, 'gcx, 'tcx>, - rty: Ty<'tcx>, + rty: Option<Ty<'tcx>>, body_id: ast::NodeId) -> FnCtxt<'a, 'gcx, 'tcx> { FnCtxt { @@ -3705,14 +3707,16 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { } hir::ExprAgain(_) => { tcx.types.never } hir::ExprRet(ref expr_opt) => { - if let Some(ref e) = *expr_opt { - self.check_expr_coercable_to_type(&e, self.ret_ty); + if self.ret_ty.is_none() { + struct_span_err!(self.tcx.sess, expr.span, E0572, + "return statement outside of function body").emit(); + } else if let Some(ref e) = *expr_opt { + self.check_expr_coercable_to_type(&e, self.ret_ty.unwrap()); } else { match self.eq_types(false, &self.misc(expr.span), - self.ret_ty, - tcx.mk_nil()) - { + self.ret_ty.unwrap(), + tcx.mk_nil()) { Ok(ok) => self.register_infer_ok_obligations(ok), Err(_) => { struct_span_err!(tcx.sess, expr.span, E0069, diff --git a/src/librustc_typeck/check/wfcheck.rs b/src/librustc_typeck/check/wfcheck.rs index 7f35c8efeff..ffdb56753fd 100644 --- a/src/librustc_typeck/check/wfcheck.rs +++ b/src/librustc_typeck/check/wfcheck.rs @@ -51,7 +51,7 @@ impl<'a, 'gcx, 'tcx> CheckWfFcxBuilder<'a, 'gcx, 'tcx> { let id = self.id; let span = self.span; self.inherited.enter(|inh| { - let fcx = FnCtxt::new(&inh, inh.ccx.tcx.types.never, id); + let fcx = FnCtxt::new(&inh, Some(inh.ccx.tcx.types.never), id); let wf_tys = f(&fcx, &mut CheckTypeWellFormedVisitor { ccx: fcx.ccx, code: code diff --git a/src/librustc_typeck/diagnostics.rs b/src/librustc_typeck/diagnostics.rs index 01e99a296e8..71507063ffc 100644 --- a/src/librustc_typeck/diagnostics.rs +++ b/src/librustc_typeck/diagnostics.rs @@ -4164,6 +4164,33 @@ target / ABI combination is currently unsupported by llvm. If necessary, you can circumvent this check using custom target specifications. "##, +E0572: r##" +A return statement was found outside of a function body. + +Erroneous code example: + +```compile_fail,E0572 +const FOO: u32 = return 0; // error: return statement outside of function body + +fn main() {} +``` + +To fix this issue, just remove the return keyword or move the expression into a +function. Example: + +``` +const FOO: u32 = 0; + +fn some_fn() -> u32 { + return FOO; +} + +fn main() { + some_fn(); +} +``` +"##, + } register_diagnostics! { diff --git a/src/test/compile-fail/E0572.rs b/src/test/compile-fail/E0572.rs new file mode 100644 index 00000000000..bbaab102de7 --- /dev/null +++ b/src/test/compile-fail/E0572.rs @@ -0,0 +1,13 @@ +// Copyright 2016 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +const FOO: u32 = return 0; //~ ERROR E0572 + +fn main() {} |