From ad78b50a86c6ac908df1c385642d46d3183740d6 Mon Sep 17 00:00:00 2001 From: Tor Hovland Date: Sat, 24 Apr 2021 13:57:41 +0200 Subject: [PATCH] Implemented suggestion. --- compiler/rustc_typeck/src/check/coercion.rs | 4 +- .../src/check/fn_ctxt/suggestions.rs | 78 ++++++++++++++++++- 2 files changed, 77 insertions(+), 5 deletions(-) diff --git a/compiler/rustc_typeck/src/check/coercion.rs b/compiler/rustc_typeck/src/check/coercion.rs index 427f967a9b6..236fec94bdb 100644 --- a/compiler/rustc_typeck/src/check/coercion.rs +++ b/compiler/rustc_typeck/src/check/coercion.rs @@ -1494,7 +1494,9 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> { if let (Some((expr, _)), Some((fn_decl, _, _))) = (expression, fcx.get_node_fn_decl(parent_item)) { - fcx.suggest_missing_return_expr(&mut err, expr, fn_decl, expected, found, parent_id); + fcx.suggest_missing_break_or_return_expr( + &mut err, expr, fn_decl, expected, found, id, parent_id, + ); } if let (Some(sp), Some(fn_output)) = (fcx.ret_coercion_span.get(), fn_output) { diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs b/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs index b7583344845..c3417247725 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs @@ -8,7 +8,7 @@ use rustc_errors::{Applicability, DiagnosticBuilder}; use rustc_hir as hir; use rustc_hir::def::{CtorOf, DefKind}; use rustc_hir::lang_items::LangItem; -use rustc_hir::{ExprKind, ItemKind, Node}; +use rustc_hir::{ExprKind, ItemKind, Node, StmtKind}; use rustc_infer::infer; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::{self, Binder, Ty}; @@ -55,7 +55,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { pointing_at_return_type = self.suggest_missing_return_type(err, &fn_decl, expected, found, can_suggest); let fn_id = self.tcx.hir().get_return_block(blk_id).unwrap(); - self.suggest_missing_return_expr(err, expr, &fn_decl, expected, found, fn_id); + self.suggest_missing_break_or_return_expr( + err, expr, &fn_decl, expected, found, blk_id, fn_id, + ); } pointing_at_return_type } @@ -472,7 +474,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } - pub(in super::super) fn suggest_missing_return_expr( + pub(in super::super) fn suggest_missing_break_or_return_expr( &self, err: &mut DiagnosticBuilder<'_>, expr: &'tcx hir::Expr<'tcx>, @@ -480,14 +482,30 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { expected: Ty<'tcx>, found: Ty<'tcx>, id: hir::HirId, + fn_id: hir::HirId, ) { if !expected.is_unit() { return; } let found = self.resolve_vars_with_obligations(found); + + if self.in_loop(id) { + if self.in_local_statement(id) { + err.multipart_suggestion( + "you might have meant to break the loop with this value", + vec![ + (expr.span.shrink_to_lo(), "break ".to_string()), + (expr.span.shrink_to_hi(), ";".to_string()), + ], + Applicability::MaybeIncorrect, + ); + return; + } + } + if let hir::FnRetTy::Return(ty) = fn_decl.output { let ty = >::ast_ty_to_ty(self, ty); - let bound_vars = self.tcx.late_bound_vars(id); + let bound_vars = self.tcx.late_bound_vars(fn_id); let ty = self.tcx.erase_late_bound_regions(Binder::bind_with_vars(ty, bound_vars)); let ty = self.normalize_associated_types_in(expr.span, ty); if self.can_coerce(found, ty) { @@ -514,4 +532,56 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { self.tcx.sess.parse_sess.expr_parentheses_needed(err, *sp, None); } } + + fn in_loop(&self, id: hir::HirId) -> bool { + if self.is_loop(id) { + return true; + } + + for (parent_id, _) in self.tcx.hir().parent_iter(id) { + if self.is_loop(parent_id) { + return true; + } + } + + false + } + + fn is_loop(&self, id: hir::HirId) -> bool { + let node = self.tcx.hir().get(id); + + if let Node::Expr(expr) = node { + if let ExprKind::Loop(..) = expr.kind { + return true; + } + } + + false + } + + fn in_local_statement(&self, id: hir::HirId) -> bool { + if self.is_local_statement(id) { + return true; + } + + for (parent_id, _) in self.tcx.hir().parent_iter(id) { + if self.is_local_statement(parent_id) { + return true; + } + } + + false + } + + fn is_local_statement(&self, id: hir::HirId) -> bool { + let node = self.tcx.hir().get(id); + + if let Node::Stmt(stmt) = node { + if let StmtKind::Local(..) = stmt.kind { + return true; + } + } + + false + } }