Auto merge of rust-lang#127377 - cuviper:beta-next, r=cuviper

[beta] backports

- Properly gate `safe` keyword in pre-expansion rust-lang#126757
- Switch back `non_local_definitions` lint to allow-by-default rust-lang#127015
- Stall computing instance for drop shim until it has no unsubstituted const params rust-lang#127068
- Update LLVM submodule rust-lang#127190

r? cuviper

Author: bors

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -562,6 +562,10 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
     gate_all!(precise_capturing, "precise captures on `impl Trait` are experimental");
     gate_all!(global_registration, "global registration is experimental");
     gate_all!(unsafe_attributes, "`#[unsafe()]` markers for attributes are experimental");
+    gate_all!(
+        unsafe_extern_blocks,
+        "`unsafe extern {}` blocks and `safe` keyword are experimental"
+    );
 
     if !visitor.features.never_patterns {
         if let Some(spans) = spans.get(&sym::never_patterns) {

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
 }

compiler/rustc_mir_transform/src/inline.rs

@@ -10,7 +10,7 @@ use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TypeVisitableExt;
-use rustc_middle::ty::{self, Instance, InstanceDef, ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{self, Instance, InstanceDef, ParamEnv, Ty, TyCtxt, TypeFlags};
 use rustc_session::config::{DebugInfo, OptLevel};
 use rustc_span::source_map::Spanned;
 use rustc_span::sym;
@@ -320,6 +320,16 @@ impl<'tcx> Inliner<'tcx> {
             InstanceDef::Intrinsic(_) | InstanceDef::Virtual(..) => {
                 return Err("instance without MIR (intrinsic / virtual)");
             }
+
+            // FIXME(#127030): `ConstParamHasTy` has bad interactions with
+            // the drop shim builder, which does not evaluate predicates in
+            // the correct param-env for types being dropped. Stall resolving
+            // the MIR for this instance until all of its const params are
+            // substituted.
+            InstanceDef::DropGlue(_, Some(ty)) if ty.has_type_flags(TypeFlags::HAS_CT_PARAM) => {
+                return Err("still needs substitution");
+            }
+
             // This cannot result in an immediate cycle since the callee MIR is a shim, which does
             // not get any optimizations run on it. Any subsequent inlining may cause cycles, but we
             // do not need to catch this here, we can wait until the inliner decides to continue

compiler/rustc_parse/src/parser/mod.rs

@@ -1221,6 +1221,9 @@ impl<'a> Parser<'a> {
         if self.eat_keyword_case(kw::Unsafe, case) {
             Safety::Unsafe(self.prev_token.uninterpolated_span())
         } else if self.eat_keyword_case(kw::Safe, case) {
+            self.psess
+                .gated_spans
+                .gate(sym::unsafe_extern_blocks, self.prev_token.uninterpolated_span());
             Safety::Safe(self.prev_token.uninterpolated_span())
         } else {
             Safety::Default

src/llvm-project

@@ -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.rs

@@ -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.stderr

@@ -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/rustdoc-ui/doctest/non_local_defs.stdout

@@ -0,0 +1,18 @@
+//@ compile-flags: -Zinline-mir=yes --crate-type=lib
+//@ build-pass
+
+use std::mem::ManuallyDrop;
+
+pub struct Foo<T, const N: usize>([T; N]);
+
+pub struct Dorp {}
+
+impl Drop for Dorp {
+    fn drop(&mut self) {}
+}
+
+#[inline]
+// SAFETY: call this with a valid allocation idk
+pub unsafe fn drop<const M: usize>(x: *mut Foo<Dorp, M>) {
+    std::ptr::drop_in_place(x);
+}

tests/ui/const-generics/polymorphic-drop-shim.rs

@@ -2,4 +2,12 @@ unsafe extern "C" {
     //~^ ERROR extern block cannot be declared unsafe
 }
 
+// We can't gate `unsafe extern` blocks themselves since they were previously
+// allowed, but we should gate the `safe` soft keyword.
+#[cfg(any())]
+unsafe extern "C" {
+    safe fn foo();
+    //~^ ERROR `unsafe extern {}` blocks and `safe` keyword are experimental
+}
+
 fn main() {}

tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.rs

@@ -4,5 +4,16 @@ error: extern block cannot be declared unsafe
 LL | unsafe extern "C" {
    | ^^^^^^
 
-error: aborting due to 1 previous error
+error[E0658]: `unsafe extern {}` blocks and `safe` keyword are experimental
+  --> $DIR/feature-gate-unsafe-extern-blocks.rs:9:5
+   |
+LL |     safe fn foo();
+   |     ^^^^
+   |
+   = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
+   = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0658`.

tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.stderr

@@ -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.rs

@@ -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);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -13,7 +13,11 @@ LL | non_local_macro::non_local_impl!(LocalStruct);
    = note: the macro `non_local_macro::non_local_impl` may come from an old version of the `non_local_macro` crate, try updating your dependency with `cargo update -p non_local_macro`
    = note: items in an anonymous const item (`const _: () = { ... }`) are treated as in the same scope as the anonymous const's declaration
    = 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/cargo-update.stderr

@@ -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.rs

@@ -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
    = 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/consts.stderr

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

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

@@ -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-trait.stderr

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