rustc: Remove unused Session argument from some attribute functions

Author: petrochenkov

clippy_lints/src/functions/must_use.rs

@@ -28,7 +28,7 @@ pub(super) fn check_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>
         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)) {
+        } 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,
@@ -51,7 +51,7 @@ pub(super) fn check_impl_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Imp
         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)
+            && !is_proc_macro(attrs)
             && trait_ref_of_method(cx, item.owner_id.def_id).is_none()
         {
             check_must_use_candidate(
@@ -78,7 +78,7 @@ pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::Tr
             check_needless_must_use(cx, sig.decl, item.owner_id, item.span, fn_header_span, attr);
         } 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,

clippy_utils/src/attrs.rs

@@ -145,8 +145,8 @@ pub fn get_unique_attr<'a>(
 
 /// Return true if the attributes contain any of `proc_macro`,
 /// `proc_macro_derive` or `proc_macro_attribute`, false otherwise
-pub fn is_proc_macro(sess: &Session, attrs: &[ast::Attribute]) -> bool {
-    attrs.iter().any(|attr| sess.is_proc_macro_attr(attr))
+pub fn is_proc_macro(attrs: &[ast::Attribute]) -> bool {
+    attrs.iter().any(|attr| attr.is_proc_macro_attr())
 }
 
 /// Return true if the attributes contain `#[doc(hidden)]`