Auto merge of #42136 - petrochenkov:oldhard, r=nikomatsakis

Turn sufficiently old compatibility lints into hard errors

It's been almost 7 months since #36894 was merged, so it's time to take the next step.

[breaking-change], needs crater run.

PRs/issues submitted to affected crates:
https://github.com/alexcrichton/ctest/pull/17
Sean1708/rusty-cheddar#55
m-r-r/helianto#3
azdle/virgil#1
rust-locale/rust-locale#24
mneumann/acyclic-network-rs#1
reem/rust-typemap#38

cc https://internals.rust-lang.org/t/moving-forward-on-forward-compatibility-lints/4204
cc #34537 #36887
Closes #36886
Closes #36888
Closes #36890
Closes #36891
Closes #36892
r? @nikomatsakis

src/librustc/lint/builtin.rs

@@ -130,68 +130,18 @@ declare_lint! {
     "detect private items in public interfaces not caught by the old implementation"
 }
 
-declare_lint! {
-    pub INACCESSIBLE_EXTERN_CRATE,
-    Deny,
-    "use of inaccessible extern crate erroneously allowed"
-}
-
 declare_lint! {
     pub INVALID_TYPE_PARAM_DEFAULT,
     Deny,
     "type parameter default erroneously allowed in invalid location"
 }
 
-declare_lint! {
-    pub ILLEGAL_FLOATING_POINT_CONSTANT_PATTERN,
-    Deny,
-    "floating-point constants cannot be used in patterns"
-}
-
-declare_lint! {
-    pub ILLEGAL_STRUCT_OR_ENUM_CONSTANT_PATTERN,
-    Deny,
-    "constants of struct or enum type can only be used in a pattern if \
-     the struct or enum has `#[derive(PartialEq, Eq)]`"
-}
-
-declare_lint! {
-    pub RAW_POINTER_DERIVE,
-    Warn,
-    "uses of #[derive] with raw pointers are rarely correct"
-}
-
-declare_lint! {
-    pub HR_LIFETIME_IN_ASSOC_TYPE,
-    Deny,
-    "binding for associated type references higher-ranked lifetime \
-     that does not appear in the trait input types"
-}
-
-declare_lint! {
-    pub OVERLAPPING_INHERENT_IMPLS,
-    Deny,
-    "two overlapping inherent impls define an item with the same name were erroneously allowed"
-}
-
 declare_lint! {
     pub RENAMED_AND_REMOVED_LINTS,
     Warn,
     "lints that have been renamed or removed"
 }
 
-declare_lint! {
-    pub SUPER_OR_SELF_IN_GLOBAL_PATH,
-    Deny,
-    "detects super or self keywords at the beginning of global path"
-}
-
-declare_lint! {
-    pub LIFETIME_UNDERSCORE,
-    Deny,
-    "lifetimes or labels named `'_` were erroneously allowed"
-}
-
 declare_lint! {
     pub RESOLVE_TRAIT_ON_DEFAULTED_UNIT,
     Warn,
@@ -280,17 +230,9 @@ impl LintPass for HardwiredLints {
             TRIVIAL_CASTS,
             TRIVIAL_NUMERIC_CASTS,
             PRIVATE_IN_PUBLIC,
-            INACCESSIBLE_EXTERN_CRATE,
             INVALID_TYPE_PARAM_DEFAULT,
-            ILLEGAL_FLOATING_POINT_CONSTANT_PATTERN,
-            ILLEGAL_STRUCT_OR_ENUM_CONSTANT_PATTERN,
             CONST_ERR,
-            RAW_POINTER_DERIVE,
-            OVERLAPPING_INHERENT_IMPLS,
             RENAMED_AND_REMOVED_LINTS,
-            SUPER_OR_SELF_IN_GLOBAL_PATH,
-            HR_LIFETIME_IN_ASSOC_TYPE,
-            LIFETIME_UNDERSCORE,
             RESOLVE_TRAIT_ON_DEFAULTED_UNIT,
             SAFE_EXTERN_STATICS,
             PATTERNS_IN_FNS_WITHOUT_BODY,

src/librustc_const_eval/pattern.rs

@@ -10,7 +10,6 @@
 
 use eval;
 
-use rustc::lint;
 use rustc::middle::const_val::{ConstEvalErr, ConstVal};
 use rustc::mir::{Field, BorrowKind, Mutability};
 use rustc::ty::{self, TyCtxt, AdtDef, Ty, TypeVariants, Region};
@@ -644,27 +643,19 @@ impl<'a, 'gcx, 'tcx> PatternContext<'a, 'gcx, 'tcx> {
         debug!("expr={:?} pat_ty={:?} pat_id={}", expr, pat_ty, pat_id);
         match pat_ty.sty {
             ty::TyFloat(_) => {
-                self.tcx.sess.add_lint(
-                    lint::builtin::ILLEGAL_FLOATING_POINT_CONSTANT_PATTERN,
-                    pat_id,
-                    span,
-                    format!("floating point constants cannot be used in patterns"));
+                self.tcx.sess.span_err(span, "floating point constants cannot be used in patterns");
             }
             ty::TyAdt(adt_def, _) if adt_def.is_union() => {
                 // Matching on union fields is unsafe, we can't hide it in constants
                 self.tcx.sess.span_err(span, "cannot use unions in constant patterns");
             }
             ty::TyAdt(adt_def, _) => {
                 if !self.tcx.has_attr(adt_def.did, "structural_match") {
-                    self.tcx.sess.add_lint(
-                        lint::builtin::ILLEGAL_STRUCT_OR_ENUM_CONSTANT_PATTERN,
-                        pat_id,
-                        span,
-                        format!("to use a constant of type `{}` \
-                                 in a pattern, \
-                                 `{}` must be annotated with `#[derive(PartialEq, Eq)]`",
-                                self.tcx.item_path_str(adt_def.did),
-                                self.tcx.item_path_str(adt_def.did)));
+                    let msg = format!("to use a constant of type `{}` in a pattern, \
+                                       `{}` must be annotated with `#[derive(PartialEq, Eq)]`",
+                                      self.tcx.item_path_str(adt_def.did),
+                                      self.tcx.item_path_str(adt_def.did));
+                    self.tcx.sess.span_err(span, &msg);
                 }
             }
             _ => { }

src/librustc_lint/lib.rs

@@ -179,7 +179,7 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
     // - Create a lint defaulting to warn as normal, with ideally the same error
     //   message you would normally give
     // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
-    //   and include the full URL.
+    //   and include the full URL, sort items in ascending order of issue numbers.
     // - Later, change lint to error
     // - Eventually, remove lint
     store.register_future_incompatible(sess,
@@ -189,48 +189,16 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
         },
         FutureIncompatibleInfo {
-            id: LintId::of(INACCESSIBLE_EXTERN_CRATE),
-            reference: "issue #36886 <https://github.com/rust-lang/rust/issues/36886>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
-            reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(SUPER_OR_SELF_IN_GLOBAL_PATH),
-            reference: "issue #36888 <https://github.com/rust-lang/rust/issues/36888>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(ILLEGAL_FLOATING_POINT_CONSTANT_PATTERN),
-            reference: "issue #36890 <https://github.com/rust-lang/rust/issues/36890>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
-            reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(ILLEGAL_STRUCT_OR_ENUM_CONSTANT_PATTERN),
-            reference: "issue #36891 <https://github.com/rust-lang/rust/issues/36891>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(HR_LIFETIME_IN_ASSOC_TYPE),
-            reference: "issue #33685 <https://github.com/rust-lang/rust/issues/33685>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(LIFETIME_UNDERSCORE),
-            reference: "issue #36892 <https://github.com/rust-lang/rust/issues/36892>",
-        },
-        FutureIncompatibleInfo {
-            id: LintId::of(RESOLVE_TRAIT_ON_DEFAULTED_UNIT),
-            reference: "issue #39216 <https://github.com/rust-lang/rust/issues/39216>",
+            id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
+            reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
         },
         FutureIncompatibleInfo {
             id: LintId::of(SAFE_EXTERN_STATICS),
-            reference: "issue #36247 <https://github.com/rust-lang/rust/issues/35112>",
+            reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
         },
         FutureIncompatibleInfo {
-            id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
-            reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
+            id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
+            reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
         },
         FutureIncompatibleInfo {
             id: LintId::of(EXTRA_REQUIREMENT_IN_IMPL),
@@ -248,18 +216,26 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
         },
+        FutureIncompatibleInfo {
+            id: LintId::of(RESOLVE_TRAIT_ON_DEFAULTED_UNIT),
+            reference: "issue #39216 <https://github.com/rust-lang/rust/issues/39216>",
+        },
         FutureIncompatibleInfo {
             id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
             reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
         },
         FutureIncompatibleInfo {
-            id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
-            reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
+            id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
+            reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
         },
         FutureIncompatibleInfo {
             id: LintId::of(ANONYMOUS_PARAMETERS),
             reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
         },
+        FutureIncompatibleInfo {
+            id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
+            reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
+        }
         ]);
 
     // Register renamed and removed lints
@@ -275,5 +251,18 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
     store.register_removed("transmute_from_fn_item_types",
         "always cast functions before transmuting them");
-    store.register_removed("overlapping_inherent_impls", "converted into hard error, see #36889");
+    store.register_removed("hr_lifetime_in_assoc_type",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
+    store.register_removed("inaccessible_extern_crate",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
+    store.register_removed("super_or_self_in_global_path",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
+    store.register_removed("overlapping_inherent_impls",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
+    store.register_removed("illegal_floating_point_constant_pattern",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
+    store.register_removed("illegal_struct_or_enum_constant_pattern",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
+    store.register_removed("lifetime_underscore",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
 }

src/librustc_passes/ast_validation.rs

@@ -36,16 +36,10 @@ impl<'a> AstValidator<'a> {
         &self.session.parse_sess.span_diagnostic
     }
 
-    fn check_label(&self, label: Ident, span: Span, id: NodeId) {
-        if label.name == keywords::StaticLifetime.name() {
+    fn check_label(&self, label: Ident, span: Span) {
+        if label.name == keywords::StaticLifetime.name() || label.name == "'_" {
             self.err_handler().span_err(span, &format!("invalid label name `{}`", label.name));
         }
-        if label.name == "'_" {
-            self.session.add_lint(lint::builtin::LIFETIME_UNDERSCORE,
-                                  id,
-                                  span,
-                                  format!("invalid label name `{}`", label.name));
-        }
     }
 
     fn invalid_visibility(&self, vis: &Visibility, span: Span, note: Option<&str>) {
@@ -104,10 +98,7 @@ impl<'a> AstValidator<'a> {
 impl<'a> Visitor<'a> for AstValidator<'a> {
     fn visit_lifetime(&mut self, lt: &'a Lifetime) {
         if lt.ident.name == "'_" {
-            self.session.add_lint(lint::builtin::LIFETIME_UNDERSCORE,
-                                  lt.id,
-                                  lt.span,
-                                  format!("invalid lifetime name `{}`", lt.ident));
+            self.err_handler().span_err(lt.span, &format!("invalid lifetime name `{}`", lt.ident));
         }
 
         visit::walk_lifetime(self, lt)
@@ -121,7 +112,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
             ExprKind::ForLoop(.., Some(ident)) |
             ExprKind::Break(Some(ident), _) |
             ExprKind::Continue(Some(ident)) => {
-                self.check_label(ident.node, ident.span, expr.id);
+                self.check_label(ident.node, ident.span);
             }
             _ => {}
         }
@@ -169,14 +160,12 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         visit::walk_ty(self, ty)
     }
 
-    fn visit_path(&mut self, path: &'a Path, id: NodeId) {
+    fn visit_path(&mut self, path: &'a Path, _: NodeId) {
         if path.segments.len() >= 2 && path.is_global() {
             let ident = path.segments[1].identifier;
             if token::Ident(ident).is_path_segment_keyword() {
-                self.session.add_lint(lint::builtin::SUPER_OR_SELF_IN_GLOBAL_PATH,
-                                      id,
-                                      path.span,
-                                      format!("global paths cannot start with `{}`", ident));
+                self.err_handler()
+                    .span_err(path.span, &format!("global paths cannot start with `{}`", ident));
             }
         }
 

src/librustc_resolve/lib.rs

@@ -1069,6 +1069,10 @@ impl<'a> NameBinding<'a> {
             _ => false,
         }
     }
+
+    fn descr(&self) -> &'static str {
+        if self.is_extern_crate() { "extern crate" } else { self.def().kind_name() }
+    }
 }
 
 /// Interns the names of the primitive types.
@@ -3424,18 +3428,7 @@ impl<'a> Resolver<'a> {
 
         for &PrivacyError(span, name, binding) in &self.privacy_errors {
             if !reported_spans.insert(span) { continue }
-            if binding.is_extern_crate() {
-                // Warn when using an inaccessible extern crate.
-                let node_id = match binding.kind {
-                    NameBindingKind::Import { directive, .. } => directive.id,
-                    _ => unreachable!(),
-                };
-                let msg = format!("extern crate `{}` is private", name);
-                self.session.add_lint(lint::builtin::INACCESSIBLE_EXTERN_CRATE, node_id, span, msg);
-            } else {
-                let def = binding.def();
-                self.session.span_err(span, &format!("{} `{}` is private", def.kind_name(), name));
-            }
+            self.session.span_err(span, &format!("{} `{}` is private", binding.descr(), name));
         }
     }
 

src/librustc_resolve/resolve_imports.rs

@@ -723,7 +723,7 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             let (ns, binding) = reexport_error.unwrap();
             if ns == TypeNS && binding.is_extern_crate() {
                 let msg = format!("extern crate `{}` is private, and cannot be reexported \
-                                   (error E0364), consider declaring with `pub`",
+                                   (error E0365), consider declaring with `pub`",
                                    ident);
                 self.session.add_lint(PRIVATE_IN_PUBLIC, directive.id, directive.span, msg);
             } else if ns == TypeNS {
@@ -792,8 +792,8 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
         self.record_def(directive.id, PathResolution::new(module.def().unwrap()));
     }
 
-    // Miscellaneous post-processing, including recording reexports, reporting conflicts,
-    // reporting the PRIVATE_IN_PUBLIC lint, and reporting unresolved imports.
+    // Miscellaneous post-processing, including recording reexports,
+    // reporting conflicts, and reporting unresolved imports.
     fn finalize_resolutions_in(&mut self, module: Module<'b>) {
         // Since import resolution is finished, globs will not define any more names.
         *module.globs.borrow_mut() = Vec::new();
@@ -838,13 +838,12 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
             }
 
             match binding.kind {
-                NameBindingKind::Import { binding: orig_binding, directive, .. } => {
+                NameBindingKind::Import { binding: orig_binding, .. } => {
                     if ns == TypeNS && orig_binding.is_variant() &&
                        !orig_binding.vis.is_at_least(binding.vis, &*self) {
-                        let msg = format!("variant `{}` is private, and cannot be reexported \
-                                           (error E0364), consider declaring its enum as `pub`",
-                                          ident);
-                        self.session.add_lint(PRIVATE_IN_PUBLIC, directive.id, binding.span, msg);
+                        let msg = format!("variant `{}` is private, and cannot be reexported, \
+                                           consider declaring its enum as `pub`", ident);
+                        self.session.span_err(binding.span, &msg);
                     }
                 }
                 NameBindingKind::Ambiguity { b1, b2, .. }

src/libsyntax/test.rs

@@ -231,20 +231,12 @@ fn mk_reexport_mod(cx: &mut TestCtxt,
                    -> (P<ast::Item>, Ident) {
     let super_ = Ident::from_str("super");
 
-    // Generate imports with `#[allow(private_in_public)]` to work around issue #36768.
-    let allow_private_in_public = cx.ext_cx.attribute(DUMMY_SP, cx.ext_cx.meta_list(
-        DUMMY_SP,
-        Symbol::intern("allow"),
-        vec![cx.ext_cx.meta_list_item_word(DUMMY_SP, Symbol::intern("private_in_public"))],
-    ));
     let items = tests.into_iter().map(|r| {
         cx.ext_cx.item_use_simple(DUMMY_SP, ast::Visibility::Public,
                                   cx.ext_cx.path(DUMMY_SP, vec![super_, r]))
-            .map_attrs(|_| vec![allow_private_in_public.clone()])
     }).chain(tested_submods.into_iter().map(|(r, sym)| {
         let path = cx.ext_cx.path(DUMMY_SP, vec![super_, r, sym]);
         cx.ext_cx.item_use_simple_(DUMMY_SP, ast::Visibility::Public, r, path)
-            .map_attrs(|_| vec![allow_private_in_public.clone()])
     })).collect();
 
     let reexport_mod = ast::Mod {

src/test/compile-fail/associated-types/bound-lifetime-constrained.rs

@@ -12,7 +12,6 @@
 
 #![allow(dead_code)]
 #![feature(rustc_attrs)]
-#![allow(hr_lifetime_in_assoc_type)]
 
 trait Foo<'a> {
     type Item;