Auto merge of #64313 - Centril:rollup-7w8b67g, r=Centril

Rollup of 5 pull requests

Successful merges:

 - #63468 (Resolve attributes in several places)
 - #64121 (Override `StepBy::{try_fold, try_rfold}`)
 - #64278 (check git in bootstrap.py)
 - #64306 (Fix typo in config.toml.example)
 - #64312 (Unify escape usage)

Failed merges:

r? @ghost

config.toml.example

@@ -184,7 +184,7 @@
 # default.
 #extended = false
 
-# Installs chosen set of extended tools if enables. By default builds all.
+# Installs chosen set of extended tools if enabled. By default builds all.
 # If chosen tool failed to build the installation fails.
 #tools = ["cargo", "rls", "clippy", "rustfmt", "analysis", "src"]
 

src/bootstrap/bootstrap.py

@@ -708,6 +708,14 @@ class RustBuild(object):
         if (not os.path.exists(os.path.join(self.rust_root, ".git"))) or \
                 self.get_toml('submodules') == "false":
             return
+
+        # check the existence of 'git' command
+        try:
+            subprocess.check_output(['git', '--version'])
+        except (subprocess.CalledProcessError, OSError):
+            print("error: `git` is not found, please make sure it's installed and in the path.")
+            sys.exit(1)
+
         slow_submodules = self.get_toml('fast-submodules') == "false"
         start_time = time()
         if slow_submodules:

src/libcore/iter/adapters/mod.rs

@@ -5,7 +5,7 @@ use crate::usize;
 use crate::intrinsics;
 
 use super::{Iterator, DoubleEndedIterator, ExactSizeIterator, FusedIterator, TrustedLen};
-use super::LoopState;
+use super::{LoopState, from_fn};
 
 mod chain;
 mod flatten;
@@ -534,6 +534,26 @@ impl<I> Iterator for StepBy<I> where I: Iterator {
             self.iter.nth(nth - 1);
         }
     }
+
+    fn try_fold<Acc, F, R>(&mut self, mut acc: Acc, mut f: F) -> R
+    where
+        F: FnMut(Acc, Self::Item) -> R,
+        R: Try<Ok = Acc>,
+    {
+        #[inline]
+        fn nth<I: Iterator>(iter: &mut I, step: usize) -> impl FnMut() -> Option<I::Item> + '_ {
+            move || iter.nth(step)
+        }
+
+        if self.first_take {
+            self.first_take = false;
+            match self.iter.next() {
+                None => return Try::from_ok(acc),
+                Some(x) => acc = f(acc, x)?,
+            }
+        }
+        from_fn(nth(&mut self.iter, self.step)).try_fold(acc, f)
+    }
 }
 
 impl<I> StepBy<I> where I: ExactSizeIterator {
@@ -567,6 +587,28 @@ impl<I> DoubleEndedIterator for StepBy<I> where I: DoubleEndedIterator + ExactSi
             .saturating_add(self.next_back_index());
         self.iter.nth_back(n)
     }
+
+    fn try_rfold<Acc, F, R>(&mut self, init: Acc, mut f: F) -> R
+    where
+        F: FnMut(Acc, Self::Item) -> R,
+        R: Try<Ok = Acc>,
+    {
+        #[inline]
+        fn nth_back<I: DoubleEndedIterator>(
+            iter: &mut I,
+            step: usize,
+        ) -> impl FnMut() -> Option<I::Item> + '_ {
+            move || iter.nth_back(step)
+        }
+
+        match self.next_back() {
+            None => Try::from_ok(init),
+            Some(x) => {
+                let acc = f(init, x)?;
+                from_fn(nth_back(&mut self.iter, self.step)).try_fold(acc, f)
+            }
+        }
+    }
 }
 
 // StepBy can only make the iterator shorter, so the len will still fit.

src/libcore/tests/iter.rs

@@ -385,6 +385,23 @@ fn test_iterator_step_by_nth_overflow() {
     assert_eq!(it.0, (usize::MAX as Bigger) * 1);
 }
 
+#[test]
+fn test_iterator_step_by_nth_try_fold() {
+    let mut it = (0..).step_by(10);
+    assert_eq!(it.try_fold(0, i8::checked_add), None);
+    assert_eq!(it.next(), Some(60));
+    assert_eq!(it.try_fold(0, i8::checked_add), None);
+    assert_eq!(it.next(), Some(90));
+
+    let mut it = (100..).step_by(10);
+    assert_eq!(it.try_fold(50, i8::checked_add), None);
+    assert_eq!(it.next(), Some(110));
+
+    let mut it = (100..=100).step_by(10);
+    assert_eq!(it.next(), Some(100));
+    assert_eq!(it.try_fold(0, i8::checked_add), Some(0));
+}
+
 #[test]
 fn test_iterator_step_by_nth_back() {
     let mut it = (0..16).step_by(5);
@@ -410,6 +427,24 @@ fn test_iterator_step_by_nth_back() {
     assert_eq!(it().nth_back(42), None);
 }
 
+#[test]
+fn test_iterator_step_by_nth_try_rfold() {
+    let mut it = (0..100).step_by(10);
+    assert_eq!(it.try_rfold(0, i8::checked_add), None);
+    assert_eq!(it.next_back(), Some(70));
+    assert_eq!(it.next(), Some(0));
+    assert_eq!(it.try_rfold(0, i8::checked_add), None);
+    assert_eq!(it.next_back(), Some(30));
+
+    let mut it = (0..100).step_by(10);
+    assert_eq!(it.try_rfold(50, i8::checked_add), None);
+    assert_eq!(it.next_back(), Some(80));
+
+    let mut it = (100..=100).step_by(10);
+    assert_eq!(it.next_back(), Some(100));
+    assert_eq!(it.try_fold(0, i8::checked_add), Some(0));
+}
+
 #[test]
 #[should_panic]
 fn test_iterator_step_by_zero() {

src/librustc/hir/map/def_collector.rs

@@ -155,6 +155,9 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
     }
 
     fn visit_variant(&mut self, v: &'a Variant) {
+        if v.is_placeholder {
+            return self.visit_macro_invoc(v.id);
+        }
         let def = self.create_def(v.id,
                                   DefPathData::TypeNs(v.ident.as_interned_str()),
                                   v.span);
@@ -168,16 +171,24 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
 
     fn visit_variant_data(&mut self, data: &'a VariantData) {
         for (index, field) in data.fields().iter().enumerate() {
+            if field.is_placeholder {
+                self.visit_macro_invoc(field.id);
+                continue;
+            }
             let name = field.ident.map(|ident| ident.name)
                 .unwrap_or_else(|| sym::integer(index));
             let def = self.create_def(field.id,
                                       DefPathData::ValueNs(name.as_interned_str()),
                                       field.span);
-            self.with_parent(def, |this| this.visit_struct_field(field));
+            self.with_parent(def, |this| visit::walk_struct_field(this, field));
         }
     }
 
     fn visit_generic_param(&mut self, param: &'a GenericParam) {
+        if param.is_placeholder {
+            self.visit_macro_invoc(param.id);
+            return;
+        }
         let name = param.ident.as_interned_str();
         let def_path_data = match param.kind {
             GenericParamKind::Lifetime { .. } => DefPathData::LifetimeNs(name),
@@ -294,4 +305,49 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
             }
         }
     }
+
+    fn visit_arm(&mut self, arm: &'a Arm) {
+        if arm.is_placeholder {
+            self.visit_macro_invoc(arm.id)
+        } else {
+            visit::walk_arm(self, arm)
+        }
+    }
+
+    fn visit_field(&mut self, f: &'a Field) {
+        if f.is_placeholder {
+            self.visit_macro_invoc(f.id)
+        } else {
+            visit::walk_field(self, f)
+        }
+    }
+
+    fn visit_field_pattern(&mut self, fp: &'a FieldPat) {
+        if fp.is_placeholder {
+            self.visit_macro_invoc(fp.id)
+        } else {
+            visit::walk_field_pattern(self, fp)
+        }
+    }
+
+    fn visit_param(&mut self, p: &'a Param) {
+        if p.is_placeholder {
+            self.visit_macro_invoc(p.id)
+        } else {
+            visit::walk_param(self, p)
+        }
+    }
+
+    fn visit_struct_field(&mut self, sf: &'a StructField) {
+        if sf.is_placeholder {
+            self.visit_macro_invoc(sf.id)
+        } else {
+            let name = sf.ident.map(|ident| ident.name)
+                .unwrap_or_else(|| panic!("don't know the field number in this context"));
+            let def = self.create_def(sf.id,
+                                        DefPathData::ValueNs(name.as_interned_str()),
+                                        sf.span);
+            self.with_parent(def, |this| visit::walk_struct_field(this, sf));
+        }
+    }
 }

src/librustc_resolve/build_reduced_graph.rs

@@ -31,7 +31,7 @@ use syntax::ast::{Name, Ident};
 use syntax::attr;
 
 use syntax::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
-use syntax::ast::{MetaItemKind, StmtKind, TraitItem, TraitItemKind, Variant};
+use syntax::ast::{MetaItemKind, StmtKind, TraitItem, TraitItemKind};
 use syntax::ext::base::{MacroKind, SyntaxExtension};
 use syntax::ext::expand::AstFragment;
 use syntax::ext::hygiene::ExpnId;
@@ -580,7 +580,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
     }
 
     /// Constructs the reduced graph for one item.
-    fn build_reduced_graph_for_item(&mut self, item: &Item) {
+    fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
         let parent_scope = &self.parent_scope;
         let parent = parent_scope.module;
         let expansion = parent_scope.expansion;
@@ -716,12 +716,10 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
             }
 
-            ItemKind::Enum(ref enum_definition, _) => {
+            ItemKind::Enum(_, _) => {
-                let module_kind = ModuleKind::Def(
+                let def_id = self.r.definitions.local_def_id(item.id);
-                    DefKind::Enum,
+                self.r.variant_vis.insert(def_id, vis);
-                    self.r.definitions.local_def_id(item.id),
+                let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
-                    ident.name,
-                );
                 let module = self.r.new_module(parent,
                                              module_kind,
                                              parent.normal_ancestor_id,
@@ -729,10 +727,6 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                                              item.span);
                 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
                 self.parent_scope.module = module;
-
-                for variant in &(*enum_definition).variants {
-                    self.build_reduced_graph_for_variant(variant, vis);
-                }
             }
 
             ItemKind::TraitAlias(..) => {
@@ -817,38 +811,6 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         }
     }
 
-    // Constructs the reduced graph for one variant. Variants exist in the
-    // type and value namespaces.
-    fn build_reduced_graph_for_variant(&mut self, variant: &Variant, vis: ty::Visibility) {
-        let parent = self.parent_scope.module;
-        let expn_id = self.parent_scope.expansion;
-        let ident = variant.ident;
-
-        // Define a name in the type namespace.
-        let def_id = self.r.definitions.local_def_id(variant.id);
-        let res = Res::Def(DefKind::Variant, def_id);
-        self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
-
-        // If the variant is marked as non_exhaustive then lower the visibility to within the
-        // crate.
-        let mut ctor_vis = vis;
-        let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
-        if has_non_exhaustive && vis == ty::Visibility::Public {
-            ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
-        }
-
-        // Define a constructor name in the value namespace.
-        // Braced variants, unlike structs, generate unusable names in
-        // value namespace, they are reserved for possible future use.
-        // It's ok to use the variant's id as a ctor id since an
-        // error will be reported on any use of such resolution anyway.
-        let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
-        let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
-        let ctor_kind = CtorKind::from_ast(&variant.data);
-        let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
-        self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
-    }
-
     /// Constructs the reduced graph for one foreign item.
     fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
         let (res, ns) = match item.node {
@@ -1188,7 +1150,6 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
             ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
             _ => false,
         };
-
         let orig_current_module = self.parent_scope.module;
         let orig_current_legacy_scope = self.parent_scope.legacy;
         self.build_reduced_graph_for_item(item);
@@ -1271,4 +1232,92 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
         }
         visit::walk_attribute(self, attr);
     }
+
+    fn visit_arm(&mut self, arm: &'b ast::Arm) {
+        if arm.is_placeholder {
+            self.visit_invoc(arm.id);
+        } else {
+            visit::walk_arm(self, arm);
+        }
+    }
+
+    fn visit_field(&mut self, f: &'b ast::Field) {
+        if f.is_placeholder {
+            self.visit_invoc(f.id);
+        } else {
+            visit::walk_field(self, f);
+        }
+    }
+
+    fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
+        if fp.is_placeholder {
+            self.visit_invoc(fp.id);
+        } else {
+            visit::walk_field_pattern(self, fp);
+        }
+    }
+
+    fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
+        if param.is_placeholder {
+            self.visit_invoc(param.id);
+        } else {
+            visit::walk_generic_param(self, param);
+        }
+    }
+
+    fn visit_param(&mut self, p: &'b ast::Param) {
+        if p.is_placeholder {
+            self.visit_invoc(p.id);
+        } else {
+            visit::walk_param(self, p);
+        }
+    }
+
+    fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
+        if sf.is_placeholder {
+            self.visit_invoc(sf.id);
+        } else {
+            visit::walk_struct_field(self, sf);
+        }
+    }
+
+    // Constructs the reduced graph for one variant. Variants exist in the
+    // type and value namespaces.
+    fn visit_variant(&mut self, variant: &'b ast::Variant) {
+        if variant.is_placeholder {
+            self.visit_invoc(variant.id);
+            return;
+        }
+
+        let parent = self.parent_scope.module;
+        let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
+        let expn_id = self.parent_scope.expansion;
+        let ident = variant.ident;
+
+        // Define a name in the type namespace.
+        let def_id = self.r.definitions.local_def_id(variant.id);
+        let res = Res::Def(DefKind::Variant, def_id);
+        self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
+
+        // If the variant is marked as non_exhaustive then lower the visibility to within the
+        // crate.
+        let mut ctor_vis = vis;
+        let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
+        if has_non_exhaustive && vis == ty::Visibility::Public {
+            ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
+        }
+
+        // Define a constructor name in the value namespace.
+        // Braced variants, unlike structs, generate unusable names in
+        // value namespace, they are reserved for possible future use.
+        // It's ok to use the variant's id as a ctor id since an
+        // error will be reported on any use of such resolution anyway.
+        let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
+        let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
+        let ctor_kind = CtorKind::from_ast(&variant.data);
+        let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
+        self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
+
+        visit::walk_variant(self, variant);
+    }
 }

src/librustc_resolve/lib.rs

@@ -952,6 +952,10 @@ pub struct Resolver<'a> {
 
     /// Features enabled for this crate.
     active_features: FxHashSet<Symbol>,
+
+    /// Stores enum visibilities to properly build a reduced graph
+    /// when visiting the correspondent variants.
+    variant_vis: DefIdMap<ty::Visibility>,
 }
 
 /// Nothing really interesting here; it just provides memory for the rest of the crate.
@@ -1214,6 +1218,7 @@ impl<'a> Resolver<'a> {
                 features.declared_lib_features.iter().map(|(feat, ..)| *feat)
                     .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
                     .collect(),
+            variant_vis: Default::default()
         }
     }
 

src/librustc_resolve/macros.rs

@@ -16,7 +16,7 @@ use syntax::attr::StabilityLevel;
 use syntax::edition::Edition;
 use syntax::ext::base::{self, InvocationRes, Indeterminate, SpecialDerives};
 use syntax::ext::base::{MacroKind, SyntaxExtension};
-use syntax::ext::expand::{AstFragment, Invocation, InvocationKind};
+use syntax::ext::expand::{AstFragment, AstFragmentKind, Invocation, InvocationKind};
 use syntax::ext::hygiene::{self, ExpnId, ExpnData, ExpnKind};
 use syntax::ext::tt::macro_rules;
 use syntax::feature_gate::{emit_feature_err, is_builtin_attr_name};
@@ -225,6 +225,26 @@ impl<'a> base::Resolver for Resolver<'a> {
             self.definitions.add_parent_module_of_macro_def(invoc_id, normal_module_def_id);
         }
 
+        match invoc.fragment_kind {
+            AstFragmentKind::Arms
+                | AstFragmentKind::Fields
+                | AstFragmentKind::FieldPats
+                | AstFragmentKind::GenericParams
+                | AstFragmentKind::Params
+                | AstFragmentKind::StructFields
+                | AstFragmentKind::Variants =>
+            {
+                if let Res::Def(..) = res {
+                    self.session.span_err(
+                        span,
+                        "expected an inert attribute, found an attribute macro"
+                    );
+                    return Ok(InvocationRes::Single(self.dummy_ext(kind)));
+                }
+            },
+            _ => {}
+        }
+
         Ok(InvocationRes::Single(ext))
     }
 

src/librustc_typeck/collect.rs

@@ -519,15 +519,15 @@ fn convert_variant_ctor(tcx: TyCtxt<'_>, ctor_id: hir::HirId) {
     tcx.predicates_of(def_id);
 }
 
-fn convert_enum_variant_types<'tcx>(
+fn convert_enum_variant_types(
-    tcx: TyCtxt<'tcx>,
+    tcx: TyCtxt<'_>,
     def_id: DefId,
     variants: &[hir::Variant]
 ) {
     let def = tcx.adt_def(def_id);
     let repr_type = def.repr.discr_type();
     let initial = repr_type.initial_discriminant(tcx);
-    let mut prev_discr = None::<Discr<'tcx>>;
+    let mut prev_discr = None::<Discr<'_>>;
 
     // fill the discriminant values and field types
     for variant in variants {

src/librustdoc/html/static/main.js

@@ -39,6 +39,14 @@ if (!DOMTokenList.prototype.remove) {
     };
 }
 
+function getSearchInput() {
+    return document.getElementsByClassName("search-input")[0];
+}
+
+function getSearchElement() {
+    return document.getElementById("search");
+}
+
 (function() {
     "use strict";
 
@@ -71,7 +79,7 @@ if (!DOMTokenList.prototype.remove) {
                      "derive",
                      "traitalias"];
 
-    var search_input = document.getElementsByClassName("search-input")[0];
+    var search_input = getSearchInput();
 
     // On the search screen, so you remain on the last tab you opened.
     //
@@ -158,7 +166,7 @@ if (!DOMTokenList.prototype.remove) {
         // If we're in mobile mode, we should add the sidebar in any case.
         hideSidebar();
         var elem;
-        var search = document.getElementById("search");
+        var search = getSearchElement();
         var i, from, to, match = window.location.hash.match(/^#?(\d+)(?:-(\d+))?$/);
         if (match) {
             from = parseInt(match[1], 10);
@@ -250,7 +258,12 @@ if (!DOMTokenList.prototype.remove) {
         return String.fromCharCode(c);
     }
 
+    function getHelpElement() {
+        return document.getElementById("help");
+    }
+
     function displayHelp(display, ev, help) {
+        var help = help ? help : getHelpElement();
         if (display === true) {
             if (hasClass(help, "hidden")) {
                 ev.preventDefault();
@@ -264,9 +277,10 @@ if (!DOMTokenList.prototype.remove) {
         }
     }
 
-    function handleEscape(ev, help) {
+    function handleEscape(ev) {
+        var help = getHelpElement();
+        var search = getSearchElement();
         hideModal();
-        var search = document.getElementById("search");
         if (hasClass(help, "hidden") === false) {
             displayHelp(false, ev, help);
         } else if (hasClass(search, "hidden") === false) {
@@ -284,22 +298,21 @@ if (!DOMTokenList.prototype.remove) {
             return;
         }
 
-        var help = document.getElementById("help");
         if (document.activeElement.tagName === "INPUT") {
             switch (getVirtualKey(ev)) {
             case "Escape":
-                handleEscape(ev, help);
+                handleEscape(ev);
                 break;
             }
         } else {
             switch (getVirtualKey(ev)) {
             case "Escape":
-                handleEscape(ev, help);
+                handleEscape(ev);
                 break;
 
             case "s":
             case "S":
-                displayHelp(false, ev, help);
+                displayHelp(false, ev);
                 hideModal();
                 ev.preventDefault();
                 focusSearchBar();
@@ -314,7 +327,7 @@ if (!DOMTokenList.prototype.remove) {
             case "?":
                 if (ev.shiftKey) {
                     hideModal();
-                    displayHelp(true, ev, help);
+                    displayHelp(true, ev);
                 }
                 break;
             }
@@ -1281,9 +1294,7 @@ if (!DOMTokenList.prototype.remove) {
                 } else if (e.which === 16) { // shift
                     // Does nothing, it's just to avoid losing "focus" on the highlighted element.
                 } else if (e.which === 27) { // escape
-                    removeClass(actives[currentTab][0], "highlighted");
+                    handleEscape(e);
-                    search_input.value = "";
-                    defocusSearchBar();
                 } else if (actives[currentTab].length > 0) {
                     removeClass(actives[currentTab][0], "highlighted");
                 }
@@ -1434,7 +1445,7 @@ if (!DOMTokenList.prototype.remove) {
                 ret_others[0] + ret_in_args[0] + ret_returned[0] + "</div>";
 
             addClass(main, "hidden");
-            var search = document.getElementById("search");
+            var search = getSearchElement();
             removeClass(search, "hidden");
             search.innerHTML = output;
             var tds = search.getElementsByTagName("td");
@@ -1644,7 +1655,7 @@ if (!DOMTokenList.prototype.remove) {
                     if (hasClass(main, "content")) {
                         removeClass(main, "hidden");
                     }
-                    var search_c = document.getElementById("search");
+                    var search_c = getSearchElement();
                     if (hasClass(search_c, "content")) {
                         addClass(search_c, "hidden");
                     }
@@ -1691,7 +1702,7 @@ if (!DOMTokenList.prototype.remove) {
                         if (hasClass(main, "content")) {
                             removeClass(main, "hidden");
                         }
-                        var search_c = document.getElementById("search");
+                        var search_c = getSearchElement();
                         if (hasClass(search_c, "content")) {
                             addClass(search_c, "hidden");
                         }
@@ -2460,7 +2471,7 @@ if (!DOMTokenList.prototype.remove) {
     var params = getQueryStringParams();
     if (params && params.search) {
         addClass(main, "hidden");
-        var search = document.getElementById("search");
+        var search = getSearchElement();
         removeClass(search, "hidden");
         search.innerHTML = "<h3 style=\"text-align: center;\">Loading search results...</h3>";
     }
@@ -2545,10 +2556,10 @@ if (!DOMTokenList.prototype.remove) {
 
 // Sets the focus on the search bar at the top of the page
 function focusSearchBar() {
-    document.getElementsByClassName("search-input")[0].focus();
+    getSearchInput().focus();
 }
 
 // Removes the focus from the search bar
 function defocusSearchBar() {
-    document.getElementsByClassName("search-input")[0].blur();
+    getSearchInput().blur();
 }

src/libsyntax/ast.rs

@@ -352,7 +352,7 @@ pub struct GenericParam {
     pub ident: Ident,
     pub attrs: ThinVec<Attribute>,
     pub bounds: GenericBounds,
-
+    pub is_placeholder: bool,
     pub kind: GenericParamKind,
 }
 
@@ -613,6 +613,7 @@ pub struct FieldPat {
     pub attrs: ThinVec<Attribute>,
     pub id: NodeId,
     pub span: Span,
+    pub is_placeholder: bool,
 }
 
 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
@@ -935,6 +936,7 @@ pub struct Arm {
     pub body: P<Expr>,
     pub span: Span,
     pub id: NodeId,
+    pub is_placeholder: bool,
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
@@ -945,6 +947,7 @@ pub struct Field {
     pub is_shorthand: bool,
     pub attrs: ThinVec<Attribute>,
     pub id: NodeId,
+    pub is_placeholder: bool,
 }
 
 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
@@ -1798,6 +1801,7 @@ pub struct Param {
     pub pat: P<Pat>,
     pub id: NodeId,
     pub span: Span,
+    pub is_placeholder: bool,
 }
 
 /// Alternative representation for `Arg`s describing `self` parameter of methods.
@@ -1859,6 +1863,7 @@ impl Param {
             span,
             ty,
             id: DUMMY_NODE_ID,
+            is_placeholder: false
         };
         match eself.node {
             SelfKind::Explicit(ty, mutbl) => param(mutbl, ty),
@@ -2054,6 +2059,8 @@ pub struct Variant {
     pub disr_expr: Option<AnonConst>,
     /// Span
     pub span: Span,
+    /// Is a macro placeholder
+    pub is_placeholder: bool,
 }
 
 /// Part of `use` item to the right of its prefix.
@@ -2216,6 +2223,7 @@ pub struct StructField {
     pub id: NodeId,
     pub ty: P<Ty>,
     pub attrs: Vec<Attribute>,
+    pub is_placeholder: bool,
 }
 
 /// Fields and constructor ids of enum variants and structs.

src/libsyntax/ext/base.rs

@@ -35,6 +35,13 @@ pub enum Annotatable {
     ForeignItem(P<ast::ForeignItem>),
     Stmt(P<ast::Stmt>),
     Expr(P<ast::Expr>),
+    Arm(ast::Arm),
+    Field(ast::Field),
+    FieldPat(ast::FieldPat),
+    GenericParam(ast::GenericParam),
+    Param(ast::Param),
+    StructField(ast::StructField),
+    Variant(ast::Variant),
 }
 
 impl HasAttrs for Annotatable {
@@ -46,6 +53,13 @@ impl HasAttrs for Annotatable {
             Annotatable::ForeignItem(ref foreign_item) => &foreign_item.attrs,
             Annotatable::Stmt(ref stmt) => stmt.attrs(),
             Annotatable::Expr(ref expr) => &expr.attrs,
+            Annotatable::Arm(ref arm) => &arm.attrs,
+            Annotatable::Field(ref field) => &field.attrs,
+            Annotatable::FieldPat(ref fp) => &fp.attrs,
+            Annotatable::GenericParam(ref gp) => &gp.attrs,
+            Annotatable::Param(ref p) => &p.attrs,
+            Annotatable::StructField(ref sf) => &sf.attrs,
+            Annotatable::Variant(ref v) => &v.attrs(),
         }
     }
 
@@ -57,6 +71,13 @@ impl HasAttrs for Annotatable {
             Annotatable::ForeignItem(foreign_item) => foreign_item.visit_attrs(f),
             Annotatable::Stmt(stmt) => stmt.visit_attrs(f),
             Annotatable::Expr(expr) => expr.visit_attrs(f),
+            Annotatable::Arm(arm) => arm.visit_attrs(f),
+            Annotatable::Field(field) => field.visit_attrs(f),
+            Annotatable::FieldPat(fp) => fp.visit_attrs(f),
+            Annotatable::GenericParam(gp) => gp.visit_attrs(f),
+            Annotatable::Param(p) => p.visit_attrs(f),
+            Annotatable::StructField(sf) => sf.visit_attrs(f),
+            Annotatable::Variant(v) => v.visit_attrs(f),
         }
     }
 }
@@ -70,6 +91,13 @@ impl Annotatable {
             Annotatable::ForeignItem(ref foreign_item) => foreign_item.span,
             Annotatable::Stmt(ref stmt) => stmt.span,
             Annotatable::Expr(ref expr) => expr.span,
+            Annotatable::Arm(ref arm) => arm.span,
+            Annotatable::Field(ref field) => field.span,
+            Annotatable::FieldPat(ref fp) => fp.pat.span,
+            Annotatable::GenericParam(ref gp) => gp.ident.span,
+            Annotatable::Param(ref p) => p.span,
+            Annotatable::StructField(ref sf) => sf.span,
+            Annotatable::Variant(ref v) => v.span,
         }
     }
 
@@ -81,6 +109,13 @@ impl Annotatable {
             Annotatable::ForeignItem(foreign_item) => visitor.visit_foreign_item(foreign_item),
             Annotatable::Stmt(stmt) => visitor.visit_stmt(stmt),
             Annotatable::Expr(expr) => visitor.visit_expr(expr),
+            Annotatable::Arm(arm) => visitor.visit_arm(arm),
+            Annotatable::Field(field) => visitor.visit_field(field),
+            Annotatable::FieldPat(fp) => visitor.visit_field_pattern(fp),
+            Annotatable::GenericParam(gp) => visitor.visit_generic_param(gp),
+            Annotatable::Param(p) => visitor.visit_param(p),
+            Annotatable::StructField(sf) =>visitor.visit_struct_field(sf),
+            Annotatable::Variant(v) => visitor.visit_variant(v),
         }
     }
 
@@ -136,6 +171,55 @@ impl Annotatable {
         }
     }
 
+    pub fn expect_arm(self) -> ast::Arm {
+        match self {
+            Annotatable::Arm(arm) => arm,
+            _ => panic!("expected match arm")
+        }
+    }
+
+    pub fn expect_field(self) -> ast::Field {
+        match self {
+            Annotatable::Field(field) => field,
+            _ => panic!("expected field")
+        }
+    }
+
+    pub fn expect_field_pattern(self) -> ast::FieldPat {
+        match self {
+            Annotatable::FieldPat(fp) => fp,
+            _ => panic!("expected field pattern")
+        }
+    }
+
+    pub fn expect_generic_param(self) -> ast::GenericParam {
+        match self {
+            Annotatable::GenericParam(gp) => gp,
+            _ => panic!("expected generic parameter")
+        }
+    }
+
+    pub fn expect_param(self) -> ast::Param {
+        match self {
+            Annotatable::Param(param) => param,
+            _ => panic!("expected parameter")
+        }
+    }
+
+    pub fn expect_struct_field(self) -> ast::StructField {
+        match self {
+            Annotatable::StructField(sf) => sf,
+            _ => panic!("expected struct field")
+        }
+    }
+
+    pub fn expect_variant(self) -> ast::Variant {
+        match self {
+            Annotatable::Variant(v) => v,
+            _ => panic!("expected variant")
+        }
+    }
+
     pub fn derive_allowed(&self) -> bool {
         match *self {
             Annotatable::Item(ref item) => match item.node {
@@ -325,6 +409,34 @@ pub trait MacResult {
     fn make_ty(self: Box<Self>) -> Option<P<ast::Ty>> {
         None
     }
+
+    fn make_arms(self: Box<Self>) -> Option<SmallVec<[ast::Arm; 1]>> {
+        None
+    }
+
+    fn make_fields(self: Box<Self>) -> Option<SmallVec<[ast::Field; 1]>> {
+        None
+    }
+
+    fn make_field_patterns(self: Box<Self>) -> Option<SmallVec<[ast::FieldPat; 1]>> {
+        None
+    }
+
+    fn make_generic_params(self: Box<Self>) -> Option<SmallVec<[ast::GenericParam; 1]>> {
+        None
+    }
+
+    fn make_params(self: Box<Self>) -> Option<SmallVec<[ast::Param; 1]>> {
+        None
+    }
+
+    fn make_struct_fields(self: Box<Self>) -> Option<SmallVec<[ast::StructField; 1]>> {
+        None
+    }
+
+    fn make_variants(self: Box<Self>) -> Option<SmallVec<[ast::Variant; 1]>> {
+        None
+    }
 }
 
 macro_rules! make_MacEager {
@@ -498,6 +610,34 @@ impl MacResult for DummyResult {
     fn make_ty(self: Box<DummyResult>) -> Option<P<ast::Ty>> {
         Some(DummyResult::raw_ty(self.span, self.is_error))
     }
+
+    fn make_arms(self: Box<DummyResult>) -> Option<SmallVec<[ast::Arm; 1]>> {
+       Some(SmallVec::new())
+    }
+
+    fn make_fields(self: Box<DummyResult>) -> Option<SmallVec<[ast::Field; 1]>> {
+        Some(SmallVec::new())
+    }
+
+    fn make_field_patterns(self: Box<DummyResult>) -> Option<SmallVec<[ast::FieldPat; 1]>> {
+        Some(SmallVec::new())
+    }
+
+    fn make_generic_params(self: Box<DummyResult>) -> Option<SmallVec<[ast::GenericParam; 1]>> {
+        Some(SmallVec::new())
+    }
+
+    fn make_params(self: Box<DummyResult>) -> Option<SmallVec<[ast::Param; 1]>> {
+        Some(SmallVec::new())
+    }
+
+    fn make_struct_fields(self: Box<DummyResult>) -> Option<SmallVec<[ast::StructField; 1]>> {
+        Some(SmallVec::new())
+    }
+
+    fn make_variants(self: Box<DummyResult>) -> Option<SmallVec<[ast::Variant; 1]>> {
+        Some(SmallVec::new())
+    }
 }
 
 /// A syntax extension kind.

src/libsyntax/ext/build.rs

@@ -166,7 +166,8 @@ impl<'a> ExtCtxt<'a> {
             bounds,
             kind: ast::GenericParamKind::Type {
                 default,
-            }
+            },
+            is_placeholder: false
         }
     }
 
@@ -207,6 +208,7 @@ impl<'a> ExtCtxt<'a> {
             attrs: attrs.into(),
             bounds,
             kind: ast::GenericParamKind::Lifetime,
+            is_placeholder: false
         }
     }
 
@@ -404,6 +406,7 @@ impl<'a> ExtCtxt<'a> {
             is_shorthand: false,
             attrs: ThinVec::new(),
             id: ast::DUMMY_NODE_ID,
+            is_placeholder: false,
         }
     }
     pub fn expr_struct(
@@ -614,6 +617,7 @@ impl<'a> ExtCtxt<'a> {
             body: expr,
             span,
             id: ast::DUMMY_NODE_ID,
+            is_placeholder: false,
         }
     }
 
@@ -701,6 +705,7 @@ impl<'a> ExtCtxt<'a> {
             pat: arg_pat,
             span,
             ty,
+            is_placeholder: false,
         }
     }
 
@@ -774,6 +779,7 @@ impl<'a> ExtCtxt<'a> {
                 vis: respan(span.shrink_to_lo(), ast::VisibilityKind::Inherited),
                 attrs: Vec::new(),
                 id: ast::DUMMY_NODE_ID,
+                is_placeholder: false,
             }
         }).collect();
 
@@ -790,6 +796,7 @@ impl<'a> ExtCtxt<'a> {
             id: ast::DUMMY_NODE_ID,
             ident,
             span,
+            is_placeholder: false,
         }
     }
 

src/libsyntax/ext/expand.rs

@@ -141,7 +141,40 @@ ast_fragments! {
         "impl item"; many fn flat_map_impl_item; fn visit_impl_item; fn make_impl_items;
     }
     ForeignItems(SmallVec<[ast::ForeignItem; 1]>) {
-        "foreign item"; many fn flat_map_foreign_item; fn visit_foreign_item; fn make_foreign_items;
+        "foreign item";
+        many fn flat_map_foreign_item;
+        fn visit_foreign_item;
+        fn make_foreign_items;
+    }
+    Arms(SmallVec<[ast::Arm; 1]>) {
+        "match arm"; many fn flat_map_arm; fn visit_arm; fn make_arms;
+    }
+    Fields(SmallVec<[ast::Field; 1]>) {
+        "field expression"; many fn flat_map_field; fn visit_field; fn make_fields;
+    }
+    FieldPats(SmallVec<[ast::FieldPat; 1]>) {
+        "field pattern";
+        many fn flat_map_field_pattern;
+        fn visit_field_pattern;
+        fn make_field_patterns;
+    }
+    GenericParams(SmallVec<[ast::GenericParam; 1]>) {
+        "generic parameter";
+        many fn flat_map_generic_param;
+        fn visit_generic_param;
+        fn make_generic_params;
+    }
+    Params(SmallVec<[ast::Param; 1]>) {
+        "function parameter"; many fn flat_map_param; fn visit_param; fn make_params;
+    }
+    StructFields(SmallVec<[ast::StructField; 1]>) {
+        "field";
+        many fn flat_map_struct_field;
+        fn visit_struct_field;
+        fn make_struct_fields;
+    }
+    Variants(SmallVec<[ast::Variant; 1]>) {
+        "variant"; many fn flat_map_variant; fn visit_variant; fn make_variants;
     }
 }
 
@@ -154,6 +187,21 @@ impl AstFragmentKind {
                                                                      -> AstFragment {
         let mut items = items.into_iter();
         match self {
+            AstFragmentKind::Arms =>
+                AstFragment::Arms(items.map(Annotatable::expect_arm).collect()),
+            AstFragmentKind::Fields =>
+                AstFragment::Fields(items.map(Annotatable::expect_field).collect()),
+            AstFragmentKind::FieldPats =>
+                AstFragment::FieldPats(items.map(Annotatable::expect_field_pattern).collect()),
+            AstFragmentKind::GenericParams =>
+                AstFragment::GenericParams(items.map(Annotatable::expect_generic_param).collect()),
+            AstFragmentKind::Params =>
+                AstFragment::Params(items.map(Annotatable::expect_param).collect()),
+            AstFragmentKind::StructFields => AstFragment::StructFields(
+                items.map(Annotatable::expect_struct_field).collect()
+            ),
+            AstFragmentKind::Variants =>
+                AstFragment::Variants(items.map(Annotatable::expect_variant).collect()),
             AstFragmentKind::Items =>
                 AstFragment::Items(items.map(Annotatable::expect_item).collect()),
             AstFragmentKind::ImplItems =>
@@ -177,7 +225,7 @@ impl AstFragmentKind {
 
 pub struct Invocation {
     pub kind: InvocationKind,
-    fragment_kind: AstFragmentKind,
+    pub fragment_kind: AstFragmentKind,
     pub expansion_data: ExpansionData,
 }
 
@@ -482,6 +530,27 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             Annotatable::Expr(mut expr) => {
                 Annotatable::Expr({ cfg.visit_expr(&mut expr); expr })
             }
+            Annotatable::Arm(arm) => {
+                Annotatable::Arm(cfg.flat_map_arm(arm).pop().unwrap())
+            }
+            Annotatable::Field(field) => {
+                Annotatable::Field(cfg.flat_map_field(field).pop().unwrap())
+            }
+            Annotatable::FieldPat(fp) => {
+                Annotatable::FieldPat(cfg.flat_map_field_pattern(fp).pop().unwrap())
+            }
+            Annotatable::GenericParam(param) => {
+                Annotatable::GenericParam(cfg.flat_map_generic_param(param).pop().unwrap())
+            }
+            Annotatable::Param(param) => {
+                Annotatable::Param(cfg.flat_map_param(param).pop().unwrap())
+            }
+            Annotatable::StructField(sf) => {
+                Annotatable::StructField(cfg.flat_map_struct_field(sf).pop().unwrap())
+            }
+            Annotatable::Variant(v) => {
+                Annotatable::Variant(cfg.flat_map_variant(v).pop().unwrap())
+            }
         }
     }
 
@@ -547,6 +616,14 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                         Annotatable::ForeignItem(item) => token::NtForeignItem(item.into_inner()),
                         Annotatable::Stmt(stmt) => token::NtStmt(stmt.into_inner()),
                         Annotatable::Expr(expr) => token::NtExpr(expr),
+                        Annotatable::Arm(..)
+                        | Annotatable::Field(..)
+                        | Annotatable::FieldPat(..)
+                        | Annotatable::GenericParam(..)
+                        | Annotatable::Param(..)
+                        | Annotatable::StructField(..)
+                        | Annotatable::Variant(..)
+                            => panic!("unexpected annotatable"),
                     })), DUMMY_SP).into();
                     let input = self.extract_proc_macro_attr_input(attr.tokens, span);
                     let tok_result = expander.expand(self.cx, span, input, item_tok);
@@ -625,6 +702,14 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             Annotatable::Expr(_) if self.cx.ecfg.proc_macro_hygiene() => return,
             Annotatable::Stmt(_) => ("statements", sym::proc_macro_hygiene),
             Annotatable::Expr(_) => ("expressions", sym::proc_macro_hygiene),
+            Annotatable::Arm(..)
+            | Annotatable::Field(..)
+            | Annotatable::FieldPat(..)
+            | Annotatable::GenericParam(..)
+            | Annotatable::Param(..)
+            | Annotatable::StructField(..)
+            | Annotatable::Variant(..)
+            => panic!("unexpected annotatable"),
         };
         emit_feature_err(
             self.cx.parse_sess,
@@ -681,6 +766,14 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             AstFragmentKind::TraitItems => return,
             AstFragmentKind::ImplItems => return,
             AstFragmentKind::ForeignItems => return,
+            AstFragmentKind::Arms
+            | AstFragmentKind::Fields
+            | AstFragmentKind::FieldPats
+            | AstFragmentKind::GenericParams
+            | AstFragmentKind::Params
+            | AstFragmentKind::StructFields
+            | AstFragmentKind::Variants
+                => panic!("unexpected AST fragment kind"),
         };
         if self.cx.ecfg.proc_macro_hygiene() {
             return
@@ -771,6 +864,14 @@ impl<'a> Parser<'a> {
             },
             AstFragmentKind::Ty => AstFragment::Ty(self.parse_ty()?),
             AstFragmentKind::Pat => AstFragment::Pat(self.parse_pat(None)?),
+            AstFragmentKind::Arms
+            | AstFragmentKind::Fields
+            | AstFragmentKind::FieldPats
+            | AstFragmentKind::GenericParams
+            | AstFragmentKind::Params
+            | AstFragmentKind::StructFields
+            | AstFragmentKind::Variants
+                => panic!("unexpected AST fragment kind"),
         })
     }
 
@@ -972,6 +1073,84 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
         });
     }
 
+    fn flat_map_arm(&mut self, arm: ast::Arm) -> SmallVec<[ast::Arm; 1]> {
+        let mut arm = configure!(self, arm);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut arm);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::Arm(arm),
+                                     AstFragmentKind::Arms, after_derive)
+                                     .make_arms();
+        }
+
+        noop_flat_map_arm(arm, self)
+    }
+
+    fn flat_map_field(&mut self, field: ast::Field) -> SmallVec<[ast::Field; 1]> {
+        let mut field = configure!(self, field);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut field);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::Field(field),
+                                     AstFragmentKind::Fields, after_derive)
+                                     .make_fields();
+        }
+
+        noop_flat_map_field(field, self)
+    }
+
+    fn flat_map_field_pattern(&mut self, fp: ast::FieldPat) -> SmallVec<[ast::FieldPat; 1]> {
+        let mut fp = configure!(self, fp);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut fp);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::FieldPat(fp),
+                                     AstFragmentKind::FieldPats, after_derive)
+                                     .make_field_patterns();
+        }
+
+        noop_flat_map_field_pattern(fp, self)
+    }
+
+    fn flat_map_param(&mut self, p: ast::Param) -> SmallVec<[ast::Param; 1]> {
+        let mut p = configure!(self, p);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut p);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::Param(p),
+                                     AstFragmentKind::Params, after_derive)
+                                     .make_params();
+        }
+
+        noop_flat_map_param(p, self)
+    }
+
+    fn flat_map_struct_field(&mut self, sf: ast::StructField) -> SmallVec<[ast::StructField; 1]> {
+        let mut sf = configure!(self, sf);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut sf);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::StructField(sf),
+                                     AstFragmentKind::StructFields, after_derive)
+                                     .make_struct_fields();
+        }
+
+        noop_flat_map_struct_field(sf, self)
+    }
+
+    fn flat_map_variant(&mut self, variant: ast::Variant) -> SmallVec<[ast::Variant; 1]> {
+        let mut variant = configure!(self, variant);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut variant);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::Variant(variant),
+                                     AstFragmentKind::Variants, after_derive)
+                                     .make_variants();
+        }
+
+        noop_flat_map_variant(variant, self)
+    }
+
     fn filter_map_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
         let expr = configure!(self, expr);
         expr.filter_map(|mut expr| {
@@ -1232,7 +1411,15 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
         param: ast::GenericParam
     ) -> SmallVec<[ast::GenericParam; 1]>
     {
-        let param = configure!(self, param);
+        let mut param = configure!(self, param);
+
+        let (attr, traits, after_derive) = self.classify_item(&mut param);
+        if attr.is_some() || !traits.is_empty() {
+            return self.collect_attr(attr, traits, Annotatable::GenericParam(param),
+                                     AstFragmentKind::GenericParams, after_derive)
+                                     .make_generic_params();
+        }
+
         noop_flat_map_generic_param(param, self)
     }
 

src/libsyntax/ext/placeholders.rs

@@ -32,6 +32,16 @@ pub fn placeholder(kind: AstFragmentKind, id: ast::NodeId) -> AstFragment {
         attrs: ThinVec::new(),
         node: ast::ExprKind::Mac(mac_placeholder()),
     });
+    let ty = P(ast::Ty {
+        id,
+        node: ast::TyKind::Mac(mac_placeholder()),
+        span,
+    });
+    let pat = P(ast::Pat {
+        id,
+        node: ast::PatKind::Mac(mac_placeholder()),
+        span,
+    });
 
     match kind {
         AstFragmentKind::Expr => AstFragment::Expr(expr_placeholder()),
@@ -67,6 +77,81 @@ pub fn placeholder(kind: AstFragmentKind, id: ast::NodeId) -> AstFragment {
             let mac = P((mac_placeholder(), ast::MacStmtStyle::Braces, ThinVec::new()));
             ast::Stmt { id, span, node: ast::StmtKind::Mac(mac) }
         }]),
+        AstFragmentKind::Arms => AstFragment::Arms(smallvec![
+            ast::Arm {
+                attrs: Default::default(),
+                body: expr_placeholder(),
+                guard: None,
+                id,
+                pat,
+                span,
+                is_placeholder: true,
+            }
+        ]),
+        AstFragmentKind::Fields => AstFragment::Fields(smallvec![
+            ast::Field {
+                attrs: Default::default(),
+                expr: expr_placeholder(),
+                id,
+                ident,
+                is_shorthand: false,
+                span,
+                is_placeholder: true,
+            }
+        ]),
+        AstFragmentKind::FieldPats => AstFragment::FieldPats(smallvec![
+            ast::FieldPat {
+                attrs: Default::default(),
+                id,
+                ident,
+                is_shorthand: false,
+                pat,
+                span,
+                is_placeholder: true,
+            }
+        ]),
+        AstFragmentKind::GenericParams => AstFragment::GenericParams(smallvec![{
+            ast::GenericParam {
+                attrs: Default::default(),
+                bounds: Default::default(),
+                id,
+                ident,
+                is_placeholder: true,
+                kind: ast::GenericParamKind::Lifetime,
+            }
+        }]),
+        AstFragmentKind::Params => AstFragment::Params(smallvec![
+            ast::Param {
+                attrs: Default::default(),
+                id,
+                pat,
+                span,
+                ty,
+                is_placeholder: true,
+            }
+        ]),
+        AstFragmentKind::StructFields => AstFragment::StructFields(smallvec![
+            ast::StructField {
+                attrs: Default::default(),
+                id,
+                ident: None,
+                span,
+                ty,
+                vis,
+                is_placeholder: true,
+            }
+        ]),
+        AstFragmentKind::Variants => AstFragment::Variants(smallvec![
+            ast::Variant {
+                attrs: Default::default(),
+                data: ast::VariantData::Struct(Default::default(), false),
+                disr_expr: None,
+                id,
+                ident,
+                span,
+                is_placeholder: true,
+            }
+        ])
     }
 }
 
@@ -105,6 +190,66 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> {
 }
 
 impl<'a, 'b> MutVisitor for PlaceholderExpander<'a, 'b> {
+    fn flat_map_arm(&mut self, arm: ast::Arm) -> SmallVec<[ast::Arm; 1]> {
+        if arm.is_placeholder {
+            self.remove(arm.id).make_arms()
+        } else {
+            noop_flat_map_arm(arm, self)
+        }
+    }
+
+    fn flat_map_field(&mut self, field: ast::Field) -> SmallVec<[ast::Field; 1]> {
+        if field.is_placeholder {
+            self.remove(field.id).make_fields()
+        } else {
+            noop_flat_map_field(field, self)
+        }
+    }
+
+    fn flat_map_field_pattern(&mut self, fp: ast::FieldPat) -> SmallVec<[ast::FieldPat; 1]> {
+        if fp.is_placeholder {
+            self.remove(fp.id).make_field_patterns()
+        } else {
+            noop_flat_map_field_pattern(fp, self)
+        }
+    }
+
+    fn flat_map_generic_param(
+        &mut self,
+        param: ast::GenericParam
+    ) -> SmallVec<[ast::GenericParam; 1]>
+    {
+        if param.is_placeholder {
+            self.remove(param.id).make_generic_params()
+        } else {
+            noop_flat_map_generic_param(param, self)
+        }
+    }
+
+    fn flat_map_param(&mut self, p: ast::Param) -> SmallVec<[ast::Param; 1]> {
+        if p.is_placeholder {
+            self.remove(p.id).make_params()
+        } else {
+            noop_flat_map_param(p, self)
+        }
+    }
+
+    fn flat_map_struct_field(&mut self, sf: ast::StructField) -> SmallVec<[ast::StructField; 1]> {
+        if sf.is_placeholder {
+            self.remove(sf.id).make_struct_fields()
+        } else {
+            noop_flat_map_struct_field(sf, self)
+        }
+    }
+
+    fn flat_map_variant(&mut self, variant: ast::Variant) -> SmallVec<[ast::Variant; 1]> {
+        if variant.is_placeholder {
+            self.remove(variant.id).make_variants()
+        } else {
+            noop_flat_map_variant(variant, self)
+        }
+    }
+
     fn flat_map_item(&mut self, item: P<ast::Item>) -> SmallVec<[P<ast::Item>; 1]> {
         match item.node {
             ast::ItemKind::Mac(_) => return self.remove(item.id).make_items(),

src/libsyntax/ext/proc_macro.rs

@@ -88,6 +88,14 @@ impl MultiItemModifier for ProcMacroDerive {
               item: Annotatable)
               -> Vec<Annotatable> {
         let item = match item {
+            Annotatable::Arm(..) |
+            Annotatable::Field(..) |
+            Annotatable::FieldPat(..) |
+            Annotatable::GenericParam(..) |
+            Annotatable::Param(..) |
+            Annotatable::StructField(..) |
+            Annotatable::Variant(..)
+                => panic!("unexpected annotatable"),
             Annotatable::Item(item) => item,
             Annotatable::ImplItem(_) |
             Annotatable::TraitItem(_) |

src/libsyntax/mut_visit.rs

@@ -370,6 +370,7 @@ pub fn noop_flat_map_field_pattern<T: MutVisitor>(
         attrs,
         id,
         ident,
+        is_placeholder: _,
         is_shorthand: _,
         pat,
         span,
@@ -403,7 +404,7 @@ pub fn noop_visit_use_tree<T: MutVisitor>(use_tree: &mut UseTree, vis: &mut T) {
 }
 
 pub fn noop_flat_map_arm<T: MutVisitor>(mut arm: Arm, vis: &mut T) -> SmallVec<[Arm; 1]> {
-    let Arm { attrs, pat, guard, body, span, id } = &mut arm;
+    let Arm { attrs, pat, guard, body, span, id, is_placeholder: _ } = &mut arm;
     visit_attrs(attrs, vis);
     vis.visit_id(id);
     vis.visit_pat(pat);
@@ -477,7 +478,7 @@ pub fn noop_visit_foreign_mod<T: MutVisitor>(foreign_mod: &mut ForeignMod, vis:
 pub fn noop_flat_map_variant<T: MutVisitor>(mut variant: Variant, vis: &mut T)
     -> SmallVec<[Variant; 1]>
 {
-    let Variant { ident, attrs, id, data, disr_expr, span } = &mut variant;
+    let Variant { ident, attrs, id, data, disr_expr, span, is_placeholder: _ } = &mut variant;
     vis.visit_ident(ident);
     visit_attrs(attrs, vis);
     vis.visit_id(id);
@@ -585,7 +586,7 @@ pub fn noop_visit_meta_item<T: MutVisitor>(mi: &mut MetaItem, vis: &mut T) {
 }
 
 pub fn noop_flat_map_param<T: MutVisitor>(mut param: Param, vis: &mut T) -> SmallVec<[Param; 1]> {
-    let Param { attrs, id, pat, span, ty } = &mut param;
+    let Param { attrs, id, pat, span, ty, is_placeholder: _ } = &mut param;
     vis.visit_id(id);
     visit_thin_attrs(attrs, vis);
     vis.visit_pat(pat);
@@ -736,7 +737,7 @@ pub fn noop_flat_map_generic_param<T: MutVisitor>(
     vis: &mut T
 ) -> SmallVec<[GenericParam; 1]>
 {
-    let GenericParam { id, ident, attrs, bounds, kind } = &mut param;
+    let GenericParam { id, ident, attrs, bounds, kind, is_placeholder: _ } = &mut param;
     vis.visit_id(id);
     vis.visit_ident(ident);
     visit_thin_attrs(attrs, vis);
@@ -828,7 +829,7 @@ pub fn noop_visit_poly_trait_ref<T: MutVisitor>(p: &mut PolyTraitRef, vis: &mut
 pub fn noop_flat_map_struct_field<T: MutVisitor>(mut sf: StructField, visitor: &mut T)
     -> SmallVec<[StructField; 1]>
 {
-    let StructField { span, ident, vis, id, ty, attrs } = &mut sf;
+    let StructField { span, ident, vis, id, ty, attrs, is_placeholder: _ } = &mut sf;
     visitor.visit_span(span);
     visit_opt(ident, |ident| visitor.visit_ident(ident));
     visitor.visit_vis(vis);
@@ -839,7 +840,7 @@ pub fn noop_flat_map_struct_field<T: MutVisitor>(mut sf: StructField, visitor: &
 }
 
 pub fn noop_flat_map_field<T: MutVisitor>(mut f: Field, vis: &mut T) -> SmallVec<[Field; 1]> {
-    let Field { ident, expr, span, is_shorthand: _, attrs, id } = &mut f;
+    let Field { ident, expr, span, is_shorthand: _, attrs, id, is_placeholder: _ } = &mut f;
     vis.visit_ident(ident);
     vis.visit_expr(expr);
     vis.visit_id(id);

src/libsyntax/parse/diagnostics.rs

@@ -29,7 +29,14 @@ crate fn dummy_arg(ident: Ident) -> Param {
         span: ident.span,
         id: ast::DUMMY_NODE_ID
     };
-    Param { attrs: ThinVec::default(), id: ast::DUMMY_NODE_ID, pat, span: ident.span, ty: P(ty) }
+    Param {
+        attrs: ThinVec::default(),
+        id: ast::DUMMY_NODE_ID,
+        pat,
+        span: ident.span,
+        ty: P(ty),
+        is_placeholder: false,
+    }
 }
 
 pub enum Error {

src/libsyntax/parse/parser.rs

@@ -1040,7 +1040,14 @@ impl<'a> Parser<'a> {
 
         let span = lo.to(self.token.span);
 
-        Ok(Param { attrs: attrs.into(), id: DUMMY_NODE_ID, pat, span, ty })
+        Ok(Param {
+            attrs: attrs.into(),
+            id: ast::DUMMY_NODE_ID,
+            is_placeholder: false,
+            pat,
+            span,
+            ty,
+        })
     }
 
     /// Parses mutability (`mut` or nothing).

src/libsyntax/parse/parser/expr.rs

@@ -1193,7 +1193,8 @@ impl<'a> Parser<'a> {
             ty: t,
             pat,
             span,
-            id: DUMMY_NODE_ID
+            id: DUMMY_NODE_ID,
+            is_placeholder: false,
         })
     }
 
@@ -1455,6 +1456,7 @@ impl<'a> Parser<'a> {
             body: expr,
             span: lo.to(hi),
             id: DUMMY_NODE_ID,
+            is_placeholder: false,
         })
     }
 
@@ -1611,6 +1613,7 @@ impl<'a> Parser<'a> {
                         is_shorthand: false,
                         attrs: ThinVec::new(),
                         id: DUMMY_NODE_ID,
+                        is_placeholder: false,
                     });
                 }
             }
@@ -1697,6 +1700,7 @@ impl<'a> Parser<'a> {
             is_shorthand,
             attrs: attrs.into(),
             id: DUMMY_NODE_ID,
+            is_placeholder: false,
         })
     }
 

src/libsyntax/parse/parser/generics.rs

@@ -49,7 +49,8 @@ impl<'a> Parser<'a> {
             bounds,
             kind: GenericParamKind::Type {
                 default,
-            }
+            },
+            is_placeholder: false
         })
     }
 
@@ -66,7 +67,8 @@ impl<'a> Parser<'a> {
             bounds: Vec::new(),
             kind: GenericParamKind::Const {
                 ty,
-            }
+            },
+            is_placeholder: false
         })
     }
 
@@ -90,6 +92,7 @@ impl<'a> Parser<'a> {
                     attrs: attrs.into(),
                     bounds,
                     kind: ast::GenericParamKind::Lifetime,
+                    is_placeholder: false
                 });
             } else if self.check_keyword(kw::Const) {
                 // Parse const parameter.

src/libsyntax/parse/parser/item.rs

@@ -1575,6 +1575,7 @@ impl<'a> Parser<'a> {
                 data: struct_def,
                 disr_expr,
                 span: vlo.to(self.prev_span),
+                is_placeholder: false,
             };
             variants.push(vr);
 
@@ -1730,6 +1731,7 @@ impl<'a> Parser<'a> {
                 id: DUMMY_NODE_ID,
                 ty,
                 attrs,
+                is_placeholder: false,
             })
         }).map(|(r, _)| r)
     }
@@ -1821,6 +1823,7 @@ impl<'a> Parser<'a> {
             id: DUMMY_NODE_ID,
             ty,
             attrs,
+            is_placeholder: false,
         })
     }
 

src/libsyntax/parse/parser/pat.rs

@@ -882,6 +882,7 @@ impl<'a> Parser<'a> {
             attrs: attrs.into(),
             id: ast::DUMMY_NODE_ID,
             span: lo.to(hi),
+            is_placeholder: false,
         })
     }
 

src/libsyntax/print/pprust/tests.rs

@@ -61,6 +61,7 @@ fn test_variant_to_string() {
             data: ast::VariantData::Unit(ast::DUMMY_NODE_ID),
             disr_expr: None,
             span: syntax_pos::DUMMY_SP,
+            is_placeholder: false,
         };
 
         let varstr = variant_to_string(&var);

src/libsyntax_ext/deriving/generic/mod.rs

@@ -1620,6 +1620,7 @@ impl<'a> TraitDef<'a> {
                             id: ast::DUMMY_NODE_ID,
                             span: pat.span.with_ctxt(self.span.ctxt()),
                             pat,
+                            is_placeholder: false
                         }
                     })
                     .collect();

src/test/ui/attrs-resolution-errors.rs

@@ -0,0 +1,40 @@
+enum FooEnum {
+    #[test]
+    //~^ ERROR expected an inert attribute, found an attribute macro
+    Bar(i32),
+}
+
+struct FooStruct {
+    #[test]
+    //~^ ERROR expected an inert attribute, found an attribute macro
+    bar: i32,
+}
+
+fn main() {
+    let foo_enum_bar = FooEnum::Bar(1);
+    match foo_enum_bar {
+        FooEnum::Bar(x) => {},
+        _ => {}
+    }
+
+    let foo_struct = FooStruct { bar: 1 };
+    match foo_struct {
+        FooStruct {
+            #[test] bar
+            //~^ ERROR expected an inert attribute, found an attribute macro
+        } => {}
+    }
+
+    match 1 {
+        0 => {}
+        #[test]
+        //~^ ERROR expected an inert attribute, found an attribute macro
+        _ => {}
+    }
+
+    let _another_foo_strunct = FooStruct {
+        #[test]
+        //~^ ERROR expected an inert attribute, found an attribute macro
+        bar: 1,
+    };
+}

src/test/ui/attrs-resolution-errors.stderr

@@ -0,0 +1,32 @@
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/attrs-resolution-errors.rs:2:5
+   |
+LL |     #[test]
+   |     ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/attrs-resolution-errors.rs:8:5
+   |
+LL |     #[test]
+   |     ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/attrs-resolution-errors.rs:23:13
+   |
+LL |             #[test] bar
+   |             ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/attrs-resolution-errors.rs:30:9
+   |
+LL |         #[test]
+   |         ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/attrs-resolution-errors.rs:36:9
+   |
+LL |         #[test]
+   |         ^^^^^^^
+
+error: aborting due to 5 previous errors
+

src/test/ui/attrs-resolution.rs

@@ -0,0 +1,37 @@
+// check-pass
+
+enum FooEnum {
+    #[rustfmt::skip]
+    Bar(i32),
+}
+
+struct FooStruct {
+    #[rustfmt::skip]
+    bar: i32,
+}
+
+fn main() {
+    let foo_enum_bar = FooEnum::Bar(1);
+    match foo_enum_bar {
+        FooEnum::Bar(x) => {}
+        _ => {}
+    }
+
+    let foo_struct = FooStruct { bar: 1 };
+    match foo_struct {
+        FooStruct {
+            #[rustfmt::skip] bar
+        } => {}
+    }
+
+    match 1 {
+        0 => {}
+        #[rustfmt::skip]
+        _ => {}
+    }
+
+    let _another_foo_strunct = FooStruct {
+        #[rustfmt::skip]
+        bar: 1,
+    };
+}

src/test/ui/conditional-compilation/cfg-generic-params.rs

@@ -16,21 +16,23 @@ struct WhereBad where for<#[cfg(no)] 'a, #[cfg(yes)] T> u8: Copy;
 //~^ ERROR only lifetime parameters can be used in this context
 
 fn f_lt_no<#[cfg_attr(no, unknown)] 'a>() {} // OK
-fn f_lt_yes<#[cfg_attr(yes, unknown)] 'a>() {} //~ ERROR attribute `unknown` is currently unknown
+fn f_lt_yes<#[cfg_attr(yes, unknown)] 'a>() {}
+//~^ ERROR cannot find attribute macro `unknown` in this scope
 fn f_ty_no<#[cfg_attr(no, unknown)] T>() {} // OK
-fn f_ty_yes<#[cfg_attr(yes, unknown)] T>() {} //~ ERROR attribute `unknown` is currently unknown
+fn f_ty_yes<#[cfg_attr(yes, unknown)] T>() {}
+//~^ ERROR cannot find attribute macro `unknown` in this scope
 
 type FnNo = for<#[cfg_attr(no, unknown)] 'a> fn(); // OK
 type FnYes = for<#[cfg_attr(yes, unknown)] 'a> fn();
-//~^ ERROR attribute `unknown` is currently unknown
+//~^ ERROR cannot find attribute macro `unknown` in this scope
 
 type PolyNo = dyn for<#[cfg_attr(no, unknown)] 'a> Copy; // OK
 type PolyYes = dyn for<#[cfg_attr(yes, unknown)] 'a> Copy;
-//~^ ERROR attribute `unknown` is currently unknown
+//~^ ERROR cannot find attribute macro `unknown` in this scope
 
 struct WhereNo where for<#[cfg_attr(no, unknown)] 'a> u8: Copy; // OK
 struct WhereYes where for<#[cfg_attr(yes, unknown)] 'a> u8: Copy;
-//~^ ERROR attribute `unknown` is currently unknown
+//~^ ERROR cannot find attribute macro `unknown` in this scope
 
 fn main() {
     f_lt::<'static>();

src/test/ui/conditional-compilation/cfg-generic-params.stderr

@@ -16,51 +16,35 @@ error: only lifetime parameters can be used in this context
 LL | struct WhereBad where for<#[cfg(no)] 'a, #[cfg(yes)] T> u8: Copy;
    |                                                      ^
 
-error[E0658]: the attribute `unknown` is currently unknown to the compiler and may have meaning added to it in the future
+error: cannot find attribute macro `unknown` in this scope
+  --> $DIR/cfg-generic-params.rs:34:43
+   |
+LL | struct WhereYes where for<#[cfg_attr(yes, unknown)] 'a> u8: Copy;
+   |                                           ^^^^^^^
+
+error: cannot find attribute macro `unknown` in this scope
+  --> $DIR/cfg-generic-params.rs:30:40
+   |
+LL | type PolyYes = dyn for<#[cfg_attr(yes, unknown)] 'a> Copy;
+   |                                        ^^^^^^^
+
+error: cannot find attribute macro `unknown` in this scope
+  --> $DIR/cfg-generic-params.rs:26:34
+   |
+LL | type FnYes = for<#[cfg_attr(yes, unknown)] 'a> fn();
+   |                                  ^^^^^^^
+
+error: cannot find attribute macro `unknown` in this scope
+  --> $DIR/cfg-generic-params.rs:22:29
+   |
+LL | fn f_ty_yes<#[cfg_attr(yes, unknown)] T>() {}
+   |                             ^^^^^^^
+
+error: cannot find attribute macro `unknown` in this scope
   --> $DIR/cfg-generic-params.rs:19:29
    |
 LL | fn f_lt_yes<#[cfg_attr(yes, unknown)] 'a>() {}
    |                             ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `unknown` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/cfg-generic-params.rs:21:29
-   |
-LL | fn f_ty_yes<#[cfg_attr(yes, unknown)] T>() {}
-   |                             ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `unknown` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/cfg-generic-params.rs:24:34
-   |
-LL | type FnYes = for<#[cfg_attr(yes, unknown)] 'a> fn();
-   |                                  ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `unknown` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/cfg-generic-params.rs:28:40
-   |
-LL | type PolyYes = dyn for<#[cfg_attr(yes, unknown)] 'a> Copy;
-   |                                        ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `unknown` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/cfg-generic-params.rs:32:43
-   |
-LL | struct WhereYes where for<#[cfg_attr(yes, unknown)] 'a> u8: Copy;
-   |                                           ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
 error: aborting due to 8 previous errors
 
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/feature-gates/feature-gate-custom_attribute2.rs

@@ -4,54 +4,54 @@
 // gate-test-custom_attribute
 
 struct StLt<#[lt_struct] 'a>(&'a u32);
-//~^ ERROR the attribute `lt_struct` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `lt_struct` in this scope
 struct StTy<#[ty_struct] I>(I);
-//~^ ERROR the attribute `ty_struct` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `ty_struct` in this scope
 
 enum EnLt<#[lt_enum] 'b> { A(&'b u32), B }
-//~^ ERROR the attribute `lt_enum` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `lt_enum` in this scope
 enum EnTy<#[ty_enum] J> { A(J), B }
-//~^ ERROR the attribute `ty_enum` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `ty_enum` in this scope
 
 trait TrLt<#[lt_trait] 'c> { fn foo(&self, _: &'c [u32]) -> &'c u32; }
-//~^ ERROR the attribute `lt_trait` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `lt_trait` in this scope
 trait TrTy<#[ty_trait] K> { fn foo(&self, _: K); }
-//~^ ERROR the attribute `ty_trait` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `ty_trait` in this scope
 
 type TyLt<#[lt_type] 'd> = &'d u32;
-//~^ ERROR the attribute `lt_type` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `lt_type` in this scope
 type TyTy<#[ty_type] L> = (L, );
-//~^ ERROR the attribute `ty_type` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `ty_type` in this scope
 
 impl<#[lt_inherent] 'e> StLt<'e> { }
-//~^ ERROR the attribute `lt_inherent` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `lt_inherent` in this scope
 impl<#[ty_inherent] M> StTy<M> { }
-//~^ ERROR the attribute `ty_inherent` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `ty_inherent` in this scope
 
 impl<#[lt_impl_for] 'f> TrLt<'f> for StLt<'f> {
-    //~^ ERROR the attribute `lt_impl_for` is currently unknown to the compiler
+    //~^ ERROR cannot find attribute macro `lt_impl_for` in this scope
     fn foo(&self, _: &'f [u32]) -> &'f u32 { loop { } }
 }
 impl<#[ty_impl_for] N> TrTy<N> for StTy<N> {
-    //~^ ERROR the attribute `ty_impl_for` is currently unknown to the compiler
+    //~^ ERROR cannot find attribute macro `ty_impl_for` in this scope
     fn foo(&self, _: N) { }
 }
 
 fn f_lt<#[lt_fn] 'g>(_: &'g [u32]) -> &'g u32 { loop { } }
-//~^ ERROR the attribute `lt_fn` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `lt_fn` in this scope
 fn f_ty<#[ty_fn] O>(_: O) { }
-//~^ ERROR the attribute `ty_fn` is currently unknown to the compiler
+//~^ ERROR cannot find attribute macro `ty_fn` in this scope
 
 impl<I> StTy<I> {
     fn m_lt<#[lt_meth] 'h>(_: &'h [u32]) -> &'h u32 { loop { } }
-    //~^ ERROR the attribute `lt_meth` is currently unknown to the compiler
+    //~^ ERROR cannot find attribute macro `lt_meth` in this scope
     fn m_ty<#[ty_meth] P>(_: P) { }
-    //~^ ERROR the attribute `ty_meth` is currently unknown to the compiler
+    //~^ ERROR cannot find attribute macro `ty_meth` in this scope
 }
 
 fn hof_lt<Q>(_: Q)
     where Q: for <#[lt_hof] 'i> Fn(&'i [u32]) -> &'i u32
-    //~^ ERROR the attribute `lt_hof` is currently unknown to the compiler
+    //~^ ERROR cannot find attribute macro `lt_hof` in this scope
 {
 }
 

src/test/ui/feature-gates/feature-gate-custom_attribute2.stderr

@@ -1,156 +1,104 @@
-error[E0658]: the attribute `lt_struct` is currently unknown to the compiler and may have meaning added to it in the future
+error: cannot find attribute macro `lt_hof` in this scope
-  --> $DIR/feature-gate-custom_attribute2.rs:6:13
+  --> $DIR/feature-gate-custom_attribute2.rs:53:21
-   |
-LL | struct StLt<#[lt_struct] 'a>(&'a u32);
-   |             ^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_struct` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:8:13
-   |
-LL | struct StTy<#[ty_struct] I>(I);
-   |             ^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_enum` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:11:11
-   |
-LL | enum EnLt<#[lt_enum] 'b> { A(&'b u32), B }
-   |           ^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_enum` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:13:11
-   |
-LL | enum EnTy<#[ty_enum] J> { A(J), B }
-   |           ^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_trait` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:16:12
-   |
-LL | trait TrLt<#[lt_trait] 'c> { fn foo(&self, _: &'c [u32]) -> &'c u32; }
-   |            ^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_trait` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:18:12
-   |
-LL | trait TrTy<#[ty_trait] K> { fn foo(&self, _: K); }
-   |            ^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_type` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:21:11
-   |
-LL | type TyLt<#[lt_type] 'd> = &'d u32;
-   |           ^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_type` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:23:11
-   |
-LL | type TyTy<#[ty_type] L> = (L, );
-   |           ^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_inherent` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:26:6
-   |
-LL | impl<#[lt_inherent] 'e> StLt<'e> { }
-   |      ^^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_inherent` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:28:6
-   |
-LL | impl<#[ty_inherent] M> StTy<M> { }
-   |      ^^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_impl_for` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:31:6
-   |
-LL | impl<#[lt_impl_for] 'f> TrLt<'f> for StLt<'f> {
-   |      ^^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_impl_for` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:35:6
-   |
-LL | impl<#[ty_impl_for] N> TrTy<N> for StTy<N> {
-   |      ^^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_fn` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:40:9
-   |
-LL | fn f_lt<#[lt_fn] 'g>(_: &'g [u32]) -> &'g u32 { loop { } }
-   |         ^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_fn` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:42:9
-   |
-LL | fn f_ty<#[ty_fn] O>(_: O) { }
-   |         ^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_meth` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:46:13
-   |
-LL |     fn m_lt<#[lt_meth] 'h>(_: &'h [u32]) -> &'h u32 { loop { } }
-   |             ^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `ty_meth` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:48:13
-   |
-LL |     fn m_ty<#[ty_meth] P>(_: P) { }
-   |             ^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `lt_hof` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/feature-gate-custom_attribute2.rs:53:19
    |
 LL |     where Q: for <#[lt_hof] 'i> Fn(&'i [u32]) -> &'i u32
-   |                   ^^^^^^^^^
+   |                     ^^^^^^
+
+error: cannot find attribute macro `ty_meth` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:48:15
    |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+LL |     fn m_ty<#[ty_meth] P>(_: P) { }
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
+   |               ^^^^^^^
+
+error: cannot find attribute macro `lt_meth` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:46:15
+   |
+LL |     fn m_lt<#[lt_meth] 'h>(_: &'h [u32]) -> &'h u32 { loop { } }
+   |               ^^^^^^^
+
+error: cannot find attribute macro `ty_fn` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:42:11
+   |
+LL | fn f_ty<#[ty_fn] O>(_: O) { }
+   |           ^^^^^
+
+error: cannot find attribute macro `lt_fn` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:40:11
+   |
+LL | fn f_lt<#[lt_fn] 'g>(_: &'g [u32]) -> &'g u32 { loop { } }
+   |           ^^^^^
+
+error: cannot find attribute macro `ty_impl_for` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:35:8
+   |
+LL | impl<#[ty_impl_for] N> TrTy<N> for StTy<N> {
+   |        ^^^^^^^^^^^
+
+error: cannot find attribute macro `lt_impl_for` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:31:8
+   |
+LL | impl<#[lt_impl_for] 'f> TrLt<'f> for StLt<'f> {
+   |        ^^^^^^^^^^^
+
+error: cannot find attribute macro `ty_inherent` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:28:8
+   |
+LL | impl<#[ty_inherent] M> StTy<M> { }
+   |        ^^^^^^^^^^^
+
+error: cannot find attribute macro `lt_inherent` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:26:8
+   |
+LL | impl<#[lt_inherent] 'e> StLt<'e> { }
+   |        ^^^^^^^^^^^
+
+error: cannot find attribute macro `ty_type` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:23:13
+   |
+LL | type TyTy<#[ty_type] L> = (L, );
+   |             ^^^^^^^
+
+error: cannot find attribute macro `lt_type` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:21:13
+   |
+LL | type TyLt<#[lt_type] 'd> = &'d u32;
+   |             ^^^^^^^
+
+error: cannot find attribute macro `ty_trait` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:18:14
+   |
+LL | trait TrTy<#[ty_trait] K> { fn foo(&self, _: K); }
+   |              ^^^^^^^^
+
+error: cannot find attribute macro `lt_trait` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:16:14
+   |
+LL | trait TrLt<#[lt_trait] 'c> { fn foo(&self, _: &'c [u32]) -> &'c u32; }
+   |              ^^^^^^^^
+
+error: cannot find attribute macro `ty_enum` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:13:13
+   |
+LL | enum EnTy<#[ty_enum] J> { A(J), B }
+   |             ^^^^^^^
+
+error: cannot find attribute macro `lt_enum` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:11:13
+   |
+LL | enum EnLt<#[lt_enum] 'b> { A(&'b u32), B }
+   |             ^^^^^^^
+
+error: cannot find attribute macro `ty_struct` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:8:15
+   |
+LL | struct StTy<#[ty_struct] I>(I);
+   |               ^^^^^^^^^
+
+error: cannot find attribute macro `lt_struct` in this scope
+  --> $DIR/feature-gate-custom_attribute2.rs:6:15
+   |
+LL | struct StLt<#[lt_struct] 'a>(&'a u32);
+   |               ^^^^^^^^^
 
 error: aborting due to 17 previous errors
 
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/issues/issue-49934-errors.rs

@@ -0,0 +1,13 @@
+fn foo<#[derive(Debug)] T>() {
+//~^ ERROR `derive` may only be applied to structs, enums and unions
+//~| ERROR expected an inert attribute, found an attribute macro
+    match 0 {
+        #[derive(Debug)]
+        //~^ ERROR `derive` may only be applied to structs, enums and unions
+        //~| ERROR expected an inert attribute, found an attribute macro
+        _ => (),
+    }
+}
+
+fn main() {
+}

src/test/ui/issues/issue-49934-errors.stderr

@@ -0,0 +1,26 @@
+error: `derive` may only be applied to structs, enums and unions
+  --> $DIR/issue-49934-errors.rs:1:8
+   |
+LL | fn foo<#[derive(Debug)] T>() {
+   |        ^^^^^^^^^^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/issue-49934-errors.rs:1:17
+   |
+LL | fn foo<#[derive(Debug)] T>() {
+   |                 ^^^^^
+
+error: `derive` may only be applied to structs, enums and unions
+  --> $DIR/issue-49934-errors.rs:5:9
+   |
+LL |         #[derive(Debug)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/issue-49934-errors.rs:5:18
+   |
+LL |         #[derive(Debug)]
+   |                  ^^^^^
+
+error: aborting due to 4 previous errors
+

src/test/ui/issues/issue-49934.rs

@@ -1,15 +1,8 @@
-// build-pass (FIXME(62277): could be check-pass?)
+// check-pass
 
 #![feature(stmt_expr_attributes)]
 #![warn(unused_attributes)] //~ NOTE lint level defined here
 
-fn foo<#[derive(Debug)] T>() { //~ WARN unused attribute
-    match 0 {
-        #[derive(Debug)] //~ WARN unused attribute
-        _ => (),
-    }
-}
-
 fn main() {
     // fold_stmt (Item)
     #[allow(dead_code)]

src/test/ui/issues/issue-49934.stderr

@@ -1,5 +1,5 @@
 warning: `#[derive]` does nothing on macro invocations
-  --> $DIR/issue-49934.rs:20:5
+  --> $DIR/issue-49934.rs:13:5
    |
 LL |     #[derive(Debug)]
    |     ^^^^^^^^^^^^^^^^
@@ -7,9 +7,9 @@ LL |     #[derive(Debug)]
    = note: this may become a hard error in a future release
 
 warning: unused attribute
-  --> $DIR/issue-49934.rs:6:8
+  --> $DIR/issue-49934.rs:19:5
    |
-LL | fn foo<#[derive(Debug)] T>() {
+LL |     #[derive(Debug)]
    |     ^^^^^^^^^^^^^^^^
    |
 note: lint level defined here
@@ -19,31 +19,19 @@ LL | #![warn(unused_attributes)]
    |         ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-49934.rs:8:9
+  --> $DIR/issue-49934.rs:23:5
    |
 LL |     #[derive(Debug)]
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-49934.rs:26:5
+  --> $DIR/issue-49934.rs:27:13
-   |
-LL |     #[derive(Debug)]
-   |     ^^^^^^^^^^^^^^^^
-
-warning: unused attribute
-  --> $DIR/issue-49934.rs:30:5
-   |
-LL |     #[derive(Debug)]
-   |     ^^^^^^^^^^^^^^^^
-
-warning: unused attribute
-  --> $DIR/issue-49934.rs:34:13
    |
 LL |     let _ = #[derive(Debug)] "Hello, world!";
    |             ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-49934.rs:39:9
+  --> $DIR/issue-49934.rs:32:9
    |
 LL |         #[derive(Debug)]
    |         ^^^^^^^^^^^^^^^^

src/test/ui/proc-macro/proc-macro-gates2.rs

@@ -10,11 +10,11 @@ extern crate test_macros;
 // should either require a feature gate or not be allowed on stable.
 
 fn _test6<#[empty_attr] T>() {}
-//~^ ERROR: unknown to the compiler
+//~^ ERROR: expected an inert attribute, found an attribute macro
 
 fn _test7() {
     match 1 {
-        #[empty_attr] //~ ERROR: unknown to the compiler
+        #[empty_attr] //~ ERROR: expected an inert attribute, found an attribute macro
         0 => {}
         _ => {}
     }

src/test/ui/proc-macro/proc-macro-gates2.stderr

@@ -1,21 +1,14 @@
-error[E0658]: the attribute `empty_attr` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-gates2.rs:12:11
    |
 LL | fn _test6<#[empty_attr] T>() {}
    |           ^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `empty_attr` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-gates2.rs:17:9
    |
 LL |         #[empty_attr]
    |         ^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs

@@ -5,7 +5,7 @@ extern "C" {
         /// Foo
         //~^ ERROR documentation comments cannot be applied to function
         #[test] a: i32,
-        //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+        //~^ ERROR expected an inert attribute, found an attribute macro
         /// Bar
         //~^ ERROR documentation comments cannot be applied to function
         #[must_use]
@@ -21,7 +21,7 @@ type FnType = fn(
     /// Foo
     //~^ ERROR documentation comments cannot be applied to function
     #[test] a: u32,
-    //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+    //~^ ERROR expected an inert attribute, found an attribute macro
     /// Bar
     //~^ ERROR documentation comments cannot be applied to function
     #[must_use]
@@ -36,7 +36,7 @@ pub fn foo(
     /// Foo
     //~^ ERROR documentation comments cannot be applied to function
     #[test] a: u32,
-    //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+    //~^ ERROR expected an inert attribute, found an attribute macro
     /// Bar
     //~^ ERROR documentation comments cannot be applied to function
     #[must_use]
@@ -56,7 +56,7 @@ impl SelfStruct {
         /// Bar
         //~^ ERROR documentation comments cannot be applied to function
         #[test] a: i32,
-        //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+        //~^ ERROR expected an inert attribute, found an attribute macro
         /// Baz
         //~^ ERROR documentation comments cannot be applied to function
         #[must_use]
@@ -77,7 +77,7 @@ impl RefStruct {
         /// Bar
         //~^ ERROR documentation comments cannot be applied to function
         #[test] a: i32,
-        //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+        //~^ ERROR expected an inert attribute, found an attribute macro
         /// Baz
         //~^ ERROR documentation comments cannot be applied to function
         #[must_use]
@@ -96,7 +96,7 @@ trait RefTrait {
         /// Bar
         //~^ ERROR documentation comments cannot be applied to function
         #[test] a: i32,
-        //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+        //~^ ERROR expected an inert attribute, found an attribute macro
         /// Baz
         //~^ ERROR documentation comments cannot be applied to function
         #[must_use]
@@ -115,7 +115,7 @@ impl RefTrait for RefStruct {
         /// Bar
         //~^ ERROR documentation comments cannot be applied to function
         #[test] a: i32,
-        //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+        //~^ ERROR expected an inert attribute, found an attribute macro
         /// Baz
         //~^ ERROR documentation comments cannot be applied to function
         #[must_use]
@@ -132,7 +132,7 @@ fn main() {
         /// Foo
         //~^ ERROR documentation comments cannot be applied to function
         #[test] a: u32,
-        //~^ ERROR the attribute `test` is currently unknown to the compiler and may have
+        //~^ ERROR expected an inert attribute, found an attribute macro
         /// Bar
         //~^ ERROR documentation comments cannot be applied to function
         #[must_use]

src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.stderr

@@ -1,3 +1,51 @@
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:7:9
+   |
+LL |         #[test] a: i32,
+   |         ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:23:5
+   |
+LL |     #[test] a: u32,
+   |     ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:38:5
+   |
+LL |     #[test] a: u32,
+   |     ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:58:9
+   |
+LL |         #[test] a: i32,
+   |         ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:79:9
+   |
+LL |         #[test] a: i32,
+   |         ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:98:9
+   |
+LL |         #[test] a: i32,
+   |         ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:117:9
+   |
+LL |         #[test] a: i32,
+   |         ^^^^^^^
+
+error: expected an inert attribute, found an attribute macro
+  --> $DIR/param-attrs-builtin-attrs.rs:134:9
+   |
+LL |         #[test] a: u32,
+   |         ^^^^^^^
+
 error: documentation comments cannot be applied to function parameters
   --> $DIR/param-attrs-builtin-attrs.rs:5:9
    |
@@ -262,78 +310,5 @@ error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-i
 LL |         #[no_mangle] b: i32
    |         ^^^^^^^^^^^^
 
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:7:9
-   |
-LL |         #[test] a: i32,
-   |         ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:23:5
-   |
-LL |     #[test] a: u32,
-   |     ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:38:5
-   |
-LL |     #[test] a: u32,
-   |     ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:58:9
-   |
-LL |         #[test] a: i32,
-   |         ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:79:9
-   |
-LL |         #[test] a: i32,
-   |         ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:98:9
-   |
-LL |         #[test] a: i32,
-   |         ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:117:9
-   |
-LL |         #[test] a: i32,
-   |         ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
-error[E0658]: the attribute `test` is currently unknown to the compiler and may have meaning added to it in the future
-  --> $DIR/param-attrs-builtin-attrs.rs:134:9
-   |
-LL |         #[test] a: u32,
-   |         ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
-
 error: aborting due to 52 previous errors
 
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.rs

@@ -9,52 +9,52 @@ use ident_mac::id;
 struct W(u8);
 
 extern "C" { fn ffi(#[id] arg1: i32, #[id] ...); }
-//~^ ERROR the attribute `id` is currently unknown to the compiler
+//~^ ERROR expected an inert attribute, found an attribute macro
-//~| ERROR the attribute `id` is currently unknown to the compiler
+//~| ERROR expected an inert attribute, found an attribute macro
 
 unsafe extern "C" fn cvar(arg1: i32, #[id] mut args: ...) {}
-//~^ ERROR the attribute `id` is currently unknown to the compiler
+//~^ ERROR expected an inert attribute, found an attribute macro
 
 type Alias = extern "C" fn(#[id] u8, #[id] ...);
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
 
 fn free(#[id] arg1: u8) {
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
     let lam = |#[id] W(x), #[id] y| ();
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
 }
 
 impl W {
     fn inherent1(#[id] self, #[id] arg1: u8) {}
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
     fn inherent2(#[id] &self, #[id] arg1: u8) {}
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
     fn inherent3<'a>(#[id] &'a mut self, #[id] arg1: u8) {}
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
     fn inherent4<'a>(#[id] self: Box<Self>, #[id] arg1: u8) {}
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
 }
 
 trait A {
     fn trait1(#[id] self, #[id] arg1: u8);
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
     fn trait2(#[id] &self, #[id] arg1: u8);
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
     fn trait3<'a>(#[id] &'a mut self, #[id] arg1: u8);
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
-    //~^ ERROR the attribute `id` is currently unknown to the compiler
+    //~^ ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
-    //~| ERROR the attribute `id` is currently unknown to the compiler
+    //~| ERROR expected an inert attribute, found an attribute macro
 }
 
 fn main() {}

src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.stderr

@@ -1,228 +1,152 @@
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:11:21
    |
 LL | extern "C" { fn ffi(#[id] arg1: i32, #[id] ...); }
    |                     ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:11:38
    |
 LL | extern "C" { fn ffi(#[id] arg1: i32, #[id] ...); }
    |                                      ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:15:38
    |
 LL | unsafe extern "C" fn cvar(arg1: i32, #[id] mut args: ...) {}
    |                                      ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:18:28
    |
 LL | type Alias = extern "C" fn(#[id] u8, #[id] ...);
    |                            ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:18:38
    |
 LL | type Alias = extern "C" fn(#[id] u8, #[id] ...);
    |                                      ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:22:9
    |
 LL | fn free(#[id] arg1: u8) {
    |         ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:24:16
    |
 LL |     let lam = |#[id] W(x), #[id] y| ();
    |                ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:24:28
    |
 LL |     let lam = |#[id] W(x), #[id] y| ();
    |                            ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:30:18
    |
 LL |     fn inherent1(#[id] self, #[id] arg1: u8) {}
    |                  ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:30:30
    |
 LL |     fn inherent1(#[id] self, #[id] arg1: u8) {}
    |                              ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:33:18
    |
 LL |     fn inherent2(#[id] &self, #[id] arg1: u8) {}
    |                  ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:33:31
    |
 LL |     fn inherent2(#[id] &self, #[id] arg1: u8) {}
    |                               ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:36:22
    |
 LL |     fn inherent3<'a>(#[id] &'a mut self, #[id] arg1: u8) {}
    |                      ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:36:42
    |
 LL |     fn inherent3<'a>(#[id] &'a mut self, #[id] arg1: u8) {}
    |                                          ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:39:22
    |
 LL |     fn inherent4<'a>(#[id] self: Box<Self>, #[id] arg1: u8) {}
    |                      ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:39:45
    |
 LL |     fn inherent4<'a>(#[id] self: Box<Self>, #[id] arg1: u8) {}
    |                                             ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:45:15
    |
 LL |     fn trait1(#[id] self, #[id] arg1: u8);
    |               ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:45:27
    |
 LL |     fn trait1(#[id] self, #[id] arg1: u8);
    |                           ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:48:15
    |
 LL |     fn trait2(#[id] &self, #[id] arg1: u8);
    |               ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:48:28
    |
 LL |     fn trait2(#[id] &self, #[id] arg1: u8);
    |                            ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:51:19
    |
 LL |     fn trait3<'a>(#[id] &'a mut self, #[id] arg1: u8);
    |                   ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:51:39
    |
 LL |     fn trait3<'a>(#[id] &'a mut self, #[id] arg1: u8);
    |                                       ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:54:19
    |
 LL |     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
    |                   ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:54:42
    |
 LL |     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
    |                                          ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
-error[E0658]: the attribute `id` is currently unknown to the compiler and may have meaning added to it in the future
+error: expected an inert attribute, found an attribute macro
   --> $DIR/proc-macro-cannot-be-used.rs:54:58
    |
 LL |     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
    |                                                          ^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
-   = help: add `#![feature(custom_attribute)]` to the crate attributes to enable
 
 error: aborting due to 25 previous errors
 
-For more information about this error, try `rustc --explain E0658`.