Auto merge of #63247 - Centril:compat-to-error, r=<try>

Transition some C-future-compatibility lints to {ERROR, DENY}

Closes #40107 (ERROR).
Closes #39207 (ERROR).
Closes #37872 (ERROR).
Closes #36887 (ERROR).
Closes #36247 (ERROR.
Closes #42238 (ERROR).
Transitions #59014 (DENY).
Transitions #57571 (DENY).
Closes #60210 (ERROR).
Transitions #35203 (DENY).

r? @petrochenkov

Author: bors

Diff for: src/doc/rustc/src/lints/listing/deny-by-default.md

@@ -22,85 +22,6 @@ error: bitshift exceeds the type's number of bits
   |
 ```
 
-## invalid-type-param-default
-
-This lint detects type parameter default erroneously allowed in invalid location. Some
-example code that triggers this lint:
-
-```rust,ignore
-fn foo<T=i32>(t: T) {}
-```
-
-This will produce:
-
-```text
-error: defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions.
- --> src/main.rs:4:8
-  |
-4 | fn foo<T=i32>(t: T) {}
-  |        ^
-  |
-  = note: `#[deny(invalid_type_param_default)]` on by default
-  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-  = note: for more information, see issue #36887 <https://github.com/rust-lang/rust/issues/36887>
-```
-
-## legacy-constructor-visibility
-
-[RFC 1506](https://github.com/rust-lang/rfcs/blob/master/text/1506-adt-kinds.md) modified some
-visibility rules, and changed the visibility of struct constructors. Some
-example code that triggers this lint:
-
-```rust,ignore
-mod m {
-    pub struct S(u8);
-    
-    fn f() {
-        // this is trying to use S from the 'use' line, but because the `u8` is
-        // not pub, it is private
-        ::S;
-    }
-}
-
-use m::S;
-```
-
-This will produce:
-
-```text
-error: private struct constructors are not usable through re-exports in outer modules
- --> src/main.rs:5:9
-  |
-5 |         ::S;
-  |         ^^^
-  |
-  = note: `#[deny(legacy_constructor_visibility)]` on by default
-  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-  = note: for more information, see issue #39207 <https://github.com/rust-lang/rust/issues/39207>
-```
-
-
-## legacy-directory-ownership
-
-The legacy_directory_ownership warning is issued when
-
-* There is a non-inline module with a `#[path]` attribute (e.g. `#[path = "foo.rs"] mod bar;`),
-* The module's file ("foo.rs" in the above example) is not named "mod.rs", and
-* The module's file contains a non-inline child module without a `#[path]` attribute.
-
-The warning can be fixed by renaming the parent module to "mod.rs" and moving
-it into its own directory if appropriate.
-
-
-## missing-fragment-specifier
-
-The missing_fragment_specifier warning is issued when an unused pattern in a
-`macro_rules!` macro definition has a meta-variable (e.g. `$e`) that is not
-followed by a fragment specifier (e.g. `:expr`).
-
-This warning can always be fixed by removing the unused pattern in the
-`macro_rules!` macro definition.
-
 ## mutable-transmutes
 
 This lint catches transmuting from `&T` to `&mut T` because it is undefined
@@ -123,7 +44,6 @@ error: mutating transmuted &mut T from &T may cause undefined behavior, consider
   |
 ```
 
-
 ## no-mangle-const-items
 
 This lint detects any `const` items with the `#[no_mangle]` attribute.
@@ -169,40 +89,10 @@ error: literal out of range for u8
   |
 ```
 
-## parenthesized-params-in-types-and-modules
-
-This lint detects incorrect parentheses. Some example code that triggers this
-lint:
-
-```rust,ignore
-let x = 5 as usize();
-```
-
-This will produce:
-
-```text
-error: parenthesized parameters may only be used with a trait
- --> src/main.rs:2:21
-  |
-2 |   let x = 5 as usize();
-  |                     ^^
-  |
-  = note: `#[deny(parenthesized_params_in_types_and_modules)]` on by default
-  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-  = note: for more information, see issue #42238 <https://github.com/rust-lang/rust/issues/42238>
-```
-
-To fix it, remove the `()`s.
-
 ## pub-use-of-private-extern-crate
 
 This lint detects a specific situation of re-exporting a private `extern crate`;
 
-## safe-extern-statics
-
-In older versions of Rust, there was a soundness issue where `extern static`s were allowed
-to be accessed in safe code. This lint now catches and denies this kind of code.
-
 ## unknown-crate-types
 
 This lint detects an unknown crate type found in a `#[crate_type]` directive. Some

Diff for: src/librustc/hir/lowering.rs

@@ -40,8 +40,7 @@ use crate::hir::def_id::{DefId, DefIndex, CRATE_DEF_INDEX};
 use crate::hir::def::{Res, DefKind, PartialRes, PerNS};
 use crate::hir::{GenericArg, ConstArg};
 use crate::hir::ptr::P;
-use crate::lint::builtin::{self, PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
-                    ELIDED_LIFETIMES_IN_PATHS};
+use crate::lint::builtin::{self, ELIDED_LIFETIMES_IN_PATHS};
 use crate::middle::cstore::CrateStore;
 use crate::session::Session;
 use crate::session::config::nightly_options;
@@ -286,7 +285,6 @@ enum ParamMode {
 
 enum ParenthesizedGenericArgs {
     Ok,
-    Warn,
     Err,
 }
 
@@ -2057,29 +2055,19 @@ impl<'a> LoweringContext<'a> {
                     };
                     let parenthesized_generic_args = match partial_res.base_res() {
                         // `a::b::Trait(Args)`
-                        Res::Def(DefKind::Trait, _)
-                            if i + 1 == proj_start => ParenthesizedGenericArgs::Ok,
+                        Res::Def(DefKind::Trait, _) if i + 1 == proj_start => {
+                            ParenthesizedGenericArgs::Ok
+                        }
                         // `a::b::Trait(Args)::TraitItem`
-                        Res::Def(DefKind::Method, _)
-                        | Res::Def(DefKind::AssocConst, _)
-                        | Res::Def(DefKind::AssocTy, _)
-                            if i + 2 == proj_start =>
-                        {
+                        Res::Def(DefKind::Method, _) |
+                        Res::Def(DefKind::AssocConst, _) |
+                        Res::Def(DefKind::AssocTy, _) if i + 2 == proj_start => {
                             ParenthesizedGenericArgs::Ok
                         }
                         // Avoid duplicated errors.
                         Res::Err => ParenthesizedGenericArgs::Ok,
                         // An error
-                        Res::Def(DefKind::Struct, _)
-                        | Res::Def(DefKind::Enum, _)
-                        | Res::Def(DefKind::Union, _)
-                        | Res::Def(DefKind::TyAlias, _)
-                        | Res::Def(DefKind::Variant, _) if i + 1 == proj_start =>
-                        {
-                            ParenthesizedGenericArgs::Err
-                        }
-                        // A warning for now, for compatibility reasons.
-                        _ => ParenthesizedGenericArgs::Warn,
+                        _ => ParenthesizedGenericArgs::Err,
                     };
 
                     let num_lifetimes = type_def_id.map_or(0, |def_id| {
@@ -2142,7 +2130,7 @@ impl<'a> LoweringContext<'a> {
                 segment,
                 param_mode,
                 0,
-                ParenthesizedGenericArgs::Warn,
+                ParenthesizedGenericArgs::Err,
                 itctx.reborrow(),
                 None,
             ));
@@ -2218,15 +2206,6 @@ impl<'a> LoweringContext<'a> {
                 }
                 GenericArgs::Parenthesized(ref data) => match parenthesized_generic_args {
                     ParenthesizedGenericArgs::Ok => self.lower_parenthesized_parameter_data(data),
-                    ParenthesizedGenericArgs::Warn => {
-                        self.sess.buffer_lint(
-                            PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
-                            CRATE_NODE_ID,
-                            data.span,
-                            msg.into(),
-                        );
-                        (hir::GenericArgs::none(), true)
-                    }
                     ParenthesizedGenericArgs::Err => {
                         let mut err = struct_span_err!(self.sess, data.span, E0214, "{}", msg);
                         err.span_label(data.span, "only `Fn` traits may use parentheses");

Diff for: src/librustc/lint/builtin.rs

@@ -139,24 +139,12 @@ declare_lint! {
     "detect public re-exports of private extern crates"
 }
 
-declare_lint! {
-    pub INVALID_TYPE_PARAM_DEFAULT,
-    Deny,
-    "type parameter default erroneously allowed in invalid location"
-}
-
 declare_lint! {
     pub RENAMED_AND_REMOVED_LINTS,
     Warn,
     "lints that have been renamed or removed"
 }
 
-declare_lint! {
-    pub SAFE_EXTERN_STATICS,
-    Deny,
-    "safe access to extern statics was erroneously allowed"
-}
-
 declare_lint! {
     pub SAFE_PACKED_BORROWS,
     Warn,
@@ -165,33 +153,8 @@ declare_lint! {
 
 declare_lint! {
     pub PATTERNS_IN_FNS_WITHOUT_BODY,
-    Warn,
-    "patterns in functions without body were erroneously allowed"
-}
-
-declare_lint! {
-    pub LEGACY_DIRECTORY_OWNERSHIP,
-    Deny,
-    "non-inline, non-`#[path]` modules (e.g., `mod foo;`) were erroneously allowed in some files \
-     not named `mod.rs`"
-}
-
-declare_lint! {
-    pub LEGACY_CONSTRUCTOR_VISIBILITY,
-    Deny,
-    "detects use of struct constructors that would be invisible with new visibility rules"
-}
-
-declare_lint! {
-    pub MISSING_FRAGMENT_SPECIFIER,
-    Deny,
-    "detects missing fragment specifiers in unused `macro_rules!` patterns"
-}
-
-declare_lint! {
-    pub PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
     Deny,
-    "detects parenthesized generic parameters in type and module names"
+    "patterns in functions without body were erroneously allowed"
 }
 
 declare_lint! {
@@ -292,12 +255,6 @@ declare_lint! {
     "detects labels that are never used"
 }
 
-declare_lint! {
-    pub DUPLICATE_MACRO_EXPORTS,
-    Deny,
-    "detects duplicate macro exports"
-}
-
 declare_lint! {
     pub INTRA_DOC_LINK_RESOLUTION_FAILURE,
     Warn,
@@ -335,13 +292,6 @@ declare_lint! {
      via the module system"
 }
 
-declare_lint! {
-    pub MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
-    Deny,
-    "macro-expanded `macro_export` macros from the current crate \
-     cannot be referred to by absolute paths"
-}
-
 declare_lint! {
     pub EXPLICIT_OUTLIVES_REQUIREMENTS,
     Allow,
@@ -359,7 +309,7 @@ declare_lint! {
 pub mod parser {
     declare_lint! {
         pub ILL_FORMED_ATTRIBUTE_INPUT,
-        Warn,
+        Deny,
         "ill-formed attribute inputs that were previously accepted and used in practice"
     }
 
@@ -385,7 +335,7 @@ declare_lint! {
 
 declare_lint! {
     pub NESTED_IMPL_TRAIT,
-    Warn,
+    Deny,
     "nested occurrence of `impl Trait` type"
 }
 
@@ -420,16 +370,10 @@ declare_lint_pass! {
         PRIVATE_IN_PUBLIC,
         EXPORTED_PRIVATE_DEPENDENCIES,
         PUB_USE_OF_PRIVATE_EXTERN_CRATE,
-        INVALID_TYPE_PARAM_DEFAULT,
         CONST_ERR,
         RENAMED_AND_REMOVED_LINTS,
-        SAFE_EXTERN_STATICS,
         SAFE_PACKED_BORROWS,
         PATTERNS_IN_FNS_WITHOUT_BODY,
-        LEGACY_DIRECTORY_OWNERSHIP,
-        LEGACY_CONSTRUCTOR_VISIBILITY,
-        MISSING_FRAGMENT_SPECIFIER,
-        PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
         LATE_BOUND_LIFETIME_ARGUMENTS,
         ORDER_DEPENDENT_TRAIT_OBJECTS,
         DEPRECATED,
@@ -445,14 +389,12 @@ declare_lint_pass! {
         ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
         UNSTABLE_NAME_COLLISIONS,
         IRREFUTABLE_LET_PATTERNS,
-        DUPLICATE_MACRO_EXPORTS,
         INTRA_DOC_LINK_RESOLUTION_FAILURE,
         MISSING_DOC_CODE_EXAMPLES,
         PRIVATE_DOC_TESTS,
         WHERE_CLAUSES_OBJECT_SAFETY,
         PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
         MACRO_USE_EXTERN_CRATE,
-        MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
         parser::ILL_FORMED_ATTRIBUTE_INPUT,
         parser::META_VARIABLE_MISUSE,
         DEPRECATED_IN_FUTURE,
@@ -470,9 +412,7 @@ pub enum BuiltinLintDiagnostics {
     Normal,
     BareTraitObject(Span, /* is_global */ bool),
     AbsPathWithModule(Span),
-    DuplicatedMacroExports(ast::Ident, Span, Span),
     ProcMacroDeriveResolutionFallback(Span),
-    MacroExpandedMacroExportsAccessedByAbsolutePaths(Span),
     ElidedLifetimesInPaths(usize, Span, bool, Span, String),
     UnknownCrateTypes(Span, String, String),
     UnusedImports(String, Vec<(Span, String)>),
@@ -553,17 +493,10 @@ impl BuiltinLintDiagnostics {
                 };
                 db.span_suggestion(span, "use `crate`", sugg, app);
             }
-            BuiltinLintDiagnostics::DuplicatedMacroExports(ident, earlier_span, later_span) => {
-                db.span_label(later_span, format!("`{}` already exported", ident));
-                db.span_note(earlier_span, "previous macro export is now shadowed");
-            }
             BuiltinLintDiagnostics::ProcMacroDeriveResolutionFallback(span) => {
                 db.span_label(span, "names from parent modules are not \
                                      accessible without an explicit import");
             }
-            BuiltinLintDiagnostics::MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def) => {
-                db.span_note(span_def, "the macro is defined here");
-            }
             BuiltinLintDiagnostics::ElidedLifetimesInPaths(
                 n, path_span, incl_angl_brckt, insertion_span, anon_lts
             ) => {

Diff for: src/librustc/mir/mod.rs

@@ -2803,7 +2803,6 @@ pub enum UnsafetyViolationKind {
     General,
     /// Permitted in const fn and regular fns.
     GeneralAndConstFn,
-    ExternStatic(hir::HirId),
     BorrowPacked(hir::HirId),
 }