diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/functions/must_use.rs')
| -rw-r--r-- | src/tools/clippy/clippy_lints/src/functions/must_use.rs | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/src/tools/clippy/clippy_lints/src/functions/must_use.rs b/src/tools/clippy/clippy_lints/src/functions/must_use.rs index 29bdc46b6..d0ad26282 100644 --- a/src/tools/clippy/clippy_lints/src/functions/must_use.rs +++ b/src/tools/clippy/clippy_lints/src/functions/must_use.rs @@ -1,7 +1,9 @@ +use hir::FnSig; use rustc_ast::ast::Attribute; use rustc_errors::Applicability; use rustc_hir::def_id::DefIdSet; use rustc_hir::{self as hir, def::Res, QPath}; +use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::{LateContext, LintContext}; use rustc_middle::{ lint::in_external_macro, @@ -22,13 +24,13 @@ use super::{DOUBLE_MUST_USE, MUST_USE_CANDIDATE, MUST_USE_UNIT}; pub(super) fn check_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) { let attrs = cx.tcx.hir().attrs(item.hir_id()); - let attr = cx.tcx.get_attr(item.owner_id.to_def_id(), sym::must_use); + let attr = cx.tcx.get_attr(item.owner_id, sym::must_use); if let hir::ItemKind::Fn(ref sig, _generics, ref body_id) = item.kind { let is_public = cx.effective_visibilities.is_exported(item.owner_id.def_id); let fn_header_span = item.span.with_hi(sig.decl.output.span().hi()); if let Some(attr) = attr { - check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr); - } else if is_public && !is_proc_macro(cx.sess(), attrs) && !attrs.iter().any(|a| a.has_name(sym::no_mangle)) { + check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr, sig); + } else if is_public && !is_proc_macro(attrs) && !attrs.iter().any(|a| a.has_name(sym::no_mangle)) { check_must_use_candidate( cx, sig.decl, @@ -47,13 +49,10 @@ pub(super) fn check_impl_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Imp let is_public = cx.effective_visibilities.is_exported(item.owner_id.def_id); let fn_header_span = item.span.with_hi(sig.decl.output.span().hi()); let attrs = cx.tcx.hir().attrs(item.hir_id()); - let attr = cx.tcx.get_attr(item.owner_id.to_def_id(), sym::must_use); + let attr = cx.tcx.get_attr(item.owner_id, sym::must_use); if let Some(attr) = attr { - check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr); - } else if is_public - && !is_proc_macro(cx.sess(), attrs) - && trait_ref_of_method(cx, item.owner_id.def_id).is_none() - { + check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr, sig); + } else if is_public && !is_proc_macro(attrs) && trait_ref_of_method(cx, item.owner_id.def_id).is_none() { check_must_use_candidate( cx, sig.decl, @@ -73,12 +72,12 @@ pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Tr let fn_header_span = item.span.with_hi(sig.decl.output.span().hi()); let attrs = cx.tcx.hir().attrs(item.hir_id()); - let attr = cx.tcx.get_attr(item.owner_id.to_def_id(), sym::must_use); + let attr = cx.tcx.get_attr(item.owner_id, sym::must_use); if let Some(attr) = attr { - check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr); + check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr, sig); } else if let hir::TraitFn::Provided(eid) = *eid { let body = cx.tcx.hir().body(eid); - if attr.is_none() && is_public && !is_proc_macro(cx.sess(), attrs) { + if attr.is_none() && is_public && !is_proc_macro(attrs) { check_must_use_candidate( cx, sig.decl, @@ -100,6 +99,7 @@ fn check_needless_must_use( item_span: Span, fn_header_span: Span, attr: &Attribute, + sig: &FnSig<'_>, ) { if in_external_macro(cx.sess(), item_span) { return; @@ -115,6 +115,15 @@ fn check_needless_must_use( }, ); } else if attr.value_str().is_none() && is_must_use_ty(cx, return_ty(cx, item_id)) { + // Ignore async functions unless Future::Output type is a must_use type + if sig.header.is_async() { + let infcx = cx.tcx.infer_ctxt().build(); + if let Some(future_ty) = infcx.get_impl_future_output_ty(return_ty(cx, item_id)) + && !is_must_use_ty(cx, future_ty) { + return; + } + } + span_lint_and_help( cx, DOUBLE_MUST_USE, |