invalid_type_param_default -> hard error

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

@@ -22,29 +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

src/librustc/lint/builtin.rs

@@ -139,12 +139,6 @@ 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,
@@ -420,7 +414,6 @@ 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,

src/librustc_lint/lib.rs

@@ -326,11 +326,6 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
             edition: None,
         },
-        FutureIncompatibleInfo {
-            id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
-            reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
-            edition: None,
-        },
         FutureIncompatibleInfo {
             id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
             reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
@@ -488,6 +483,8 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
         "converted into hard error, see https://github.com/rust-lang/rust/issues/57742");
     store.register_removed("incoherent_fundamental_impls",
         "converted into hard error, see https://github.com/rust-lang/rust/issues/46205");
+    store.register_removed("invalid_type_param_default",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/36887");
 }
 
 pub fn register_internals(store: &mut lint::LintStore, sess: Option<&Session>) {

src/librustc_typeck/collect.rs

@@ -17,7 +17,6 @@
 use crate::astconv::{AstConv, Bounds, SizedByDefault};
 use crate::constrained_generic_params as cgp;
 use crate::check::intrinsic::intrisic_operation_unsafety;
-use crate::lint;
 use crate::middle::resolve_lifetime as rl;
 use crate::middle::weak_lang_items;
 use rustc::mir::mono::Linkage;
@@ -1014,9 +1013,7 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::Generics {
 
                         if !allow_defaults && default.is_some() {
                             if !tcx.features().default_type_parameter_fallback {
-                                tcx.lint_hir(
-                                    lint::builtin::INVALID_TYPE_PARAM_DEFAULT,
-                                    param.hir_id,
+                                tcx.sess.span_err(
                                     param.span,
                                     &format!(
                                         "defaults for type parameters are only allowed in \

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

@@ -1,12 +1,8 @@
-#![allow(unused)]
-
-fn avg<T=i32>(_: T) {}
+fn avg<T = i32>(_: T) {}
 //~^ ERROR defaults for type parameters are only allowed
-//~| WARN this was previously accepted
 
 struct S<T>(T);
-impl<T=i32> S<T> {}
+impl<T = i32> S<T> {}
 //~^ ERROR defaults for type parameters are only allowed
-//~| WARN this was previously accepted
 
 fn main() {}

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

@@ -1,21 +1,14 @@
 error: defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions.
-  --> $DIR/feature-gate-default_type_parameter_fallback.rs:3:8
+  --> $DIR/feature-gate-default_type_parameter_fallback.rs:1:8
    |
-LL | fn avg<T=i32>(_: T) {}
+LL | fn avg<T = i32>(_: 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>
 
 error: defaults for type parameters are only allowed in `struct`, `enum`, `type`, or `trait` definitions.
-  --> $DIR/feature-gate-default_type_parameter_fallback.rs:8:6
+  --> $DIR/feature-gate-default_type_parameter_fallback.rs:5:6
    |
-LL | impl<T=i32> S<T> {}
+LL | impl<T = i32> S<T> {}
    |      ^
-   |
-   = 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>
 
 error: aborting due to 2 previous errors