Switch back non_local_definitions lint to allow-by-default

as request T-lang is requesting some major changes in the lint inner
workings in rust-lang#126768#issuecomment-2192634762

compiler/rustc_lint/src/non_local_def.rs

@@ -50,7 +50,7 @@ declare_lint! {
     /// All nested bodies (functions, enum discriminant, array length, consts) (expect for
     /// `const _: Ty = { ... }` in top-level module, which is still undecided) are checked.
     pub NON_LOCAL_DEFINITIONS,
-    Warn,
+    Allow,
     "checks for non-local definitions",
     report_in_external_macro
 }

tests/rustdoc-ui/doctest/non_local_defs.rs

@@ -4,6 +4,8 @@
 //@ normalize-stderr-test: "tests/rustdoc-ui/doctest" -> "$$DIR"
 //@ normalize-stdout-test "finished in \d+\.\d+s" -> "finished in $$TIME"
 
+#![doc(test(attr(warn(non_local_definitions))))]
+
 //! ```
 //! #[macro_export]
 //! macro_rules! a_macro { () => {} }

tests/rustdoc-ui/doctest/non_local_defs.stderr

@@ -1,13 +1,17 @@
 warning: non-local `macro_rules!` definition, `#[macro_export]` macro should be written at top level module
-  --> $DIR/non_local_defs.rs:9:1
+  --> $DIR/non_local_defs.rs:11:1
    |
 LL | macro_rules! a_macro { () => {} }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: remove the `#[macro_export]` or make this doc-test a standalone test with its own `fn main() { ... }`
    = note: a `macro_rules!` definition is non-local if it is nested inside an item and has a `#[macro_export]` attribute
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
-   = note: `#[warn(non_local_definitions)]` on by default
+note: the lint level is defined here
+  --> $DIR/non_local_defs.rs:8:9
+   |
+LL | #![warn(non_local_definitions)]
+   |         ^^^^^^^^^^^^^^^^^^^^^
 
 warning: 1 warning emitted
 

tests/rustdoc-ui/doctest/non_local_defs.stdout

@@ -1,6 +1,6 @@
 
 running 1 test
-test $DIR/non_local_defs.rs - (line 7) ... ok
+test $DIR/non_local_defs.rs - (line 9) ... ok
 
 test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
 

tests/ui/lint/non-local-defs/cargo-update.rs

@@ -10,6 +10,8 @@
 // of the `cargo update` suggestion we assert it here.
 //@ error-pattern: `cargo update -p non_local_macro`
 
+#![warn(non_local_definitions)]
+
 extern crate non_local_macro;
 
 struct LocalStruct;

tests/ui/lint/non-local-defs/cargo-update.stderr

@@ -1,5 +1,5 @@
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/cargo-update.rs:17:1
+  --> $DIR/cargo-update.rs:19:1
    |
 LL | non_local_macro::non_local_impl!(LocalStruct);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -14,7 +14,11 @@ LL | non_local_macro::non_local_impl!(LocalStruct);
    = note: an `impl` is never scoped, even when it is nested inside an item, as it may impact type checking outside of that item, which can be the case if neither the trait or the self type are at the same nesting level as the `impl`
    = note: items in an anonymous const item (`const _: () = { ... }`) are treated as in the same scope as the anonymous const's declaration for the purpose of this lint
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
-   = note: `#[warn(non_local_definitions)]` on by default
+note: the lint level is defined here
+  --> $DIR/cargo-update.rs:13:9
+   |
+LL | #![warn(non_local_definitions)]
+   |         ^^^^^^^^^^^^^^^^^^^^^
    = note: this warning originates in the macro `non_local_macro::non_local_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 warning: 1 warning emitted

tests/ui/lint/non-local-defs/consts.rs

@@ -2,6 +2,8 @@
 //@ edition:2021
 //@ rustc-env:CARGO_CRATE_NAME=non_local_def
 
+#![warn(non_local_definitions)]
+
 struct Test;
 
 trait Uto {}

tests/ui/lint/non-local-defs/consts.stderr

@@ -1,5 +1,5 @@
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:13:5
+  --> $DIR/consts.rs:15:5
    |
 LL | const Z: () = {
    | -----------
@@ -17,10 +17,14 @@ LL |     impl Uto for &Test {}
    = note: an `impl` is never scoped, even when it is nested inside an item, as it may impact type checking outside of that item, which can be the case if neither the trait or the self type are at the same nesting level as the `impl`
    = note: items in an anonymous const item (`const _: () = { ... }`) are treated as in the same scope as the anonymous const's declaration for the purpose of this lint
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
-   = note: `#[warn(non_local_definitions)]` on by default
+note: the lint level is defined here
+  --> $DIR/consts.rs:5:9
+   |
+LL | #![warn(non_local_definitions)]
+   |         ^^^^^^^^^^^^^^^^^^^^^
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:24:5
+  --> $DIR/consts.rs:26:5
    |
 LL | static A: u32 = {
    | ------------- move the `impl` block outside of this static `A`
@@ -36,7 +40,7 @@ LL |     impl Uto2 for Test {}
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:32:5
+  --> $DIR/consts.rs:34:5
    |
 LL | const B: u32 = {
    | ------------ move the `impl` block outside of this constant `B`
@@ -52,7 +56,7 @@ LL |     impl Uto3 for Test {}
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:43:5
+  --> $DIR/consts.rs:45:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`
@@ -65,7 +69,7 @@ LL |     impl Test {
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:50:9
+  --> $DIR/consts.rs:52:9
    |
 LL |       const {
    |  ___________-
@@ -84,7 +88,7 @@ LL | |     };
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:59:9
+  --> $DIR/consts.rs:61:9
    |
 LL |     const _: u32 = {
    |     ------------ move the `impl` block outside of this constant `_` and up 2 bodies
@@ -98,7 +102,7 @@ LL |         impl Test {
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:72:9
+  --> $DIR/consts.rs:74:9
    |
 LL |     let _a = || {
    |              -- move the `impl` block outside of this closure `<unnameable>` and up 2 bodies
@@ -113,7 +117,7 @@ LL |         impl Uto9 for Test {}
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/consts.rs:79:9
+  --> $DIR/consts.rs:81:9
    |
 LL |       type A = [u32; {
    |  ____________________-

tests/ui/lint/non-local-defs/exhaustive-trait.rs

@@ -1,6 +1,8 @@
 //@ check-pass
 //@ edition:2021
 
+#![warn(non_local_definitions)]
+
 struct Dog;
 
 fn main() {

tests/ui/lint/non-local-defs/exhaustive-trait.stderr

@@ -1,5 +1,5 @@
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/exhaustive-trait.rs:7:5
+  --> $DIR/exhaustive-trait.rs:9:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`
@@ -12,10 +12,14 @@ LL |     impl PartialEq<()> for Dog {
    = note: `impl` may be usable in bounds, etc. from outside the expression, which might e.g. make something constructible that previously wasn't, because it's still on a publicly-visible type
    = note: an `impl` is never scoped, even when it is nested inside an item, as it may impact type checking outside of that item, which can be the case if neither the trait or the self type are at the same nesting level as the `impl`
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
-   = note: `#[warn(non_local_definitions)]` on by default
+note: the lint level is defined here
+  --> $DIR/exhaustive-trait.rs:4:9
+   |
+LL | #![warn(non_local_definitions)]
+   |         ^^^^^^^^^^^^^^^^^^^^^
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/exhaustive-trait.rs:14:5
+  --> $DIR/exhaustive-trait.rs:16:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`
@@ -31,7 +35,7 @@ LL |     impl PartialEq<()> for &Dog {
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/exhaustive-trait.rs:21:5
+  --> $DIR/exhaustive-trait.rs:23:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`
@@ -47,7 +51,7 @@ LL |     impl PartialEq<Dog> for () {
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/exhaustive-trait.rs:28:5
+  --> $DIR/exhaustive-trait.rs:30:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`
@@ -63,7 +67,7 @@ LL |     impl PartialEq<&Dog> for () {
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/exhaustive-trait.rs:35:5
+  --> $DIR/exhaustive-trait.rs:37:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`
@@ -79,7 +83,7 @@ LL |     impl PartialEq<Dog> for &Dog {
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>
 
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
-  --> $DIR/exhaustive-trait.rs:42:5
+  --> $DIR/exhaustive-trait.rs:44:5
    |
 LL | fn main() {
    | --------- move the `impl` block outside of this function `main`

tests/ui/lint/non-local-defs/exhaustive.rs

@@ -1,6 +1,8 @@
 //@ check-pass
 //@ edition:2021
 
+#![warn(non_local_definitions)]
+
 use std::fmt::Display;
 
 trait Trait {}