diff options
| -rw-r--r-- | src/librustc/traits/error_reporting/suggestions.rs | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/src/librustc/traits/error_reporting/suggestions.rs b/src/librustc/traits/error_reporting/suggestions.rs index bf6891214ac..189412f60b9 100644 --- a/src/librustc/traits/error_reporting/suggestions.rs +++ b/src/librustc/traits/error_reporting/suggestions.rs @@ -13,6 +13,7 @@ use rustc_errors::{ }; use rustc_hir as hir; use rustc_hir::def_id::DefId; +use rustc_hir::def::DefKind; use rustc_hir::intravisit::Visitor; use rustc_hir::Node; use rustc_span::source_map::SourceMap; @@ -1366,14 +1367,40 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { if let Some(expr_id) = expr { let expr = hir.expect_expr(expr_id); - let is_ref = tables.expr_adjustments(expr).iter().any(|adj| adj.is_region_borrow()); + debug!("target_ty evaluated from {:?}", expr); + let parent = hir.get_parent_node(expr_id); if let Some(hir::Node::Expr(e)) = hir.find(parent) { - let method_span = hir.span(parent); - if tables.is_method_call(e) && is_ref { + let parent_span = hir.span(parent); + let parent_did = parent.owner_def_id(); + // ```rust + // impl T { + // fn foo(&self) -> i32 {} + // } + // T.foo(); + // ^^^^^^^ a temporary `&T` created inside this method call due to `&self` + // ``` + // + let is_region_borrow = + tables.expr_adjustments(expr).iter().any(|adj| adj.is_region_borrow()); + + // ```rust + // struct Foo(*const u8); + // bar(Foo(std::ptr::null())).await; + // ^^^^^^^^^^^^^^^^^^^^^ raw-ptr `*T` created inside this struct ctor. + // ``` + debug!("parent_def_kind: {:?}", self.tcx.def_kind(parent_did)); + let is_raw_borrow_inside_fn_like_call = match self.tcx.def_kind(parent_did) { + Some(DefKind::Fn) | Some(DefKind::Ctor(..)) => target_ty.is_unsafe_ptr(), + _ => false, + }; + + if (tables.is_method_call(e) && is_region_borrow) + || is_raw_borrow_inside_fn_like_call + { err.span_help( - method_span, - "consider moving this method call into a `let` \ + parent_span, + "consider moving this into a `let` \ binding to create a shorter lived borrow", ); } |