Auto merge of rust-lang#147284 - cuviper:beta-next, r=cuviper

[beta] backports

- remove incorrect fast path rust-lang#146919
- Fix infinite recursion in Path::eq with String rust-lang#146958
- Make #[link="dl"] an FCW rather than an error rust-lang#147262

r? cuviper

Author: bors

compiler/rustc_attr_parsing/src/attributes/link_attrs.rs

@@ -65,10 +65,22 @@ impl<S: Stage> CombineAttributeParser<S> for LinkParser {
         cx: &'c mut AcceptContext<'_, '_, S>,
         args: &'c ArgParser<'_>,
     ) -> impl IntoIterator<Item = Self::Item> + 'c {
-        let mut result = None;
-        let Some(items) = args.list() else {
-            cx.expected_list(cx.attr_span);
-            return result;
+        let items = match args {
+            ArgParser::List(list) => list,
+            // This is an edgecase added because making this a hard error would break too many crates
+            // Specifically `#[link = "dl"]` is accepted with a FCW
+            // For more information, see https://github.com/rust-lang/rust/pull/143193
+            ArgParser::NameValue(nv) if nv.value_as_str().is_some_and(|v| v == sym::dl) => {
+                let suggestions = <Self as CombineAttributeParser<S>>::TEMPLATE
+                    .suggestions(cx.attr_style, "link");
+                let span = cx.attr_span;
+                cx.emit_lint(AttributeLintKind::IllFormedAttributeInput { suggestions }, span);
+                return None;
+            }
+            _ => {
+                cx.expected_list(cx.attr_span);
+                return None;
+            }
         };
 
         let sess = cx.sess();
@@ -113,7 +125,7 @@ impl<S: Stage> CombineAttributeParser<S> for LinkParser {
                 }
             };
             if !cont {
-                return result;
+                return None;
             }
         }
 
@@ -202,7 +214,7 @@ impl<S: Stage> CombineAttributeParser<S> for LinkParser {
         }
         let Some((name, name_span)) = name else {
             cx.emit_err(LinkRequiresName { span: cx.attr_span });
-            return result;
+            return None;
         };
 
         // Do this outside of the loop so that `import_name_type` can be specified before `kind`.
@@ -218,15 +230,14 @@ impl<S: Stage> CombineAttributeParser<S> for LinkParser {
             cx.emit_err(RawDylibNoNul { span: name_span });
         }
 
-        result = Some(LinkEntry {
+        Some(LinkEntry {
             span: cx.attr_span,
             kind: kind.unwrap_or(NativeLibKind::Unspecified),
             name,
             cfg,
             verbatim,
             import_name_type,
-        });
-        result
+        })
     }
 }
 

compiler/rustc_span/src/symbol.rs

@@ -871,6 +871,7 @@ symbols! {
         div,
         div_assign,
         diverging_block_default,
+        dl,
         do_not_recommend,
         doc,
         doc_alias,

compiler/rustc_trait_selection/src/infer.rs

@@ -9,7 +9,7 @@ use rustc_middle::infer::canonical::{
     Canonical, CanonicalQueryInput, CanonicalQueryResponse, QueryResponse,
 };
 use rustc_middle::traits::query::NoSolution;
-use rustc_middle::ty::{self, GenericArg, Ty, TyCtxt, TypeFoldable, TypeVisitableExt, Upcast};
+use rustc_middle::ty::{self, GenericArg, Ty, TyCtxt, TypeFoldable, Upcast};
 use rustc_span::DUMMY_SP;
 use tracing::instrument;
 
@@ -31,19 +31,7 @@ impl<'tcx> InferCtxt<'tcx> {
 
     fn type_is_copy_modulo_regions(&self, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool {
         let ty = self.resolve_vars_if_possible(ty);
-
-        // FIXME(#132279): This should be removed as it causes us to incorrectly
-        // handle opaques in their defining scope, and stalled coroutines.
-        if !self.next_trait_solver() && !(param_env, ty).has_infer() && !ty.has_coroutines() {
-            return self.tcx.type_is_copy_modulo_regions(self.typing_env(param_env), ty);
-        }
-
         let copy_def_id = self.tcx.require_lang_item(LangItem::Copy, DUMMY_SP);
-
-        // This can get called from typeck (by euv), and `moves_by_default`
-        // rightly refuses to work with inference variables, but
-        // moves_by_default has a cache, which we want to use in other
-        // cases.
         traits::type_known_to_meet_bound_modulo_regions(self, param_env, ty, copy_def_id)
     }
 

library/std/src/path.rs

@@ -2107,31 +2107,31 @@ impl PartialEq for PathBuf {
 impl cmp::PartialEq<str> for PathBuf {
     #[inline]
     fn eq(&self, other: &str) -> bool {
-        Path::eq(self, other)
+        self.as_path() == other
     }
 }
 
 #[stable(feature = "eq_str_for_path", since = "1.91.0")]
 impl cmp::PartialEq<PathBuf> for str {
     #[inline]
     fn eq(&self, other: &PathBuf) -> bool {
-        other == self
+        self == other.as_path()
     }
 }
 
 #[stable(feature = "eq_str_for_path", since = "1.91.0")]
 impl cmp::PartialEq<String> for PathBuf {
     #[inline]
     fn eq(&self, other: &String) -> bool {
-        **self == **other
+        self.as_path() == other.as_str()
     }
 }
 
 #[stable(feature = "eq_str_for_path", since = "1.91.0")]
 impl cmp::PartialEq<PathBuf> for String {
     #[inline]
     fn eq(&self, other: &PathBuf) -> bool {
-        other == self
+        self.as_str() == other.as_path()
     }
 }
 
@@ -3426,15 +3426,15 @@ impl cmp::PartialEq<Path> for str {
 impl cmp::PartialEq<String> for Path {
     #[inline]
     fn eq(&self, other: &String) -> bool {
-        self == &*other
+        self == other.as_str()
     }
 }
 
 #[stable(feature = "eq_str_for_path", since = "1.91.0")]
 impl cmp::PartialEq<Path> for String {
     #[inline]
     fn eq(&self, other: &Path) -> bool {
-        other == self
+        self.as_str() == other
     }
 }
 

library/std/tests/path.rs

@@ -2528,7 +2528,17 @@ fn normalize_lexically() {
 }
 
 #[test]
-/// See issue#146183
-fn compare_path_to_str() {
-    assert!(&PathBuf::from("x") == "x");
+/// See issue#146183 and issue#146940
+fn compare_path_like_to_str_like() {
+    let path_buf = PathBuf::from("x");
+    let path = Path::new("x");
+    let s = String::from("x");
+    assert!(path == "x");
+    assert!("x" == path);
+    assert!(path == &s);
+    assert!(&s == path);
+    assert!(&path_buf == "x");
+    assert!("x" == &path_buf);
+    assert!(path_buf == s);
+    assert!(s == path_buf);
 }

src/tools/cargo

@@ -0,0 +1,10 @@
+Future incompatibility report: Future breakage diagnostic:
+warning: valid forms for the attribute are `#[link(name = "...")]`, `#[link(name = "...", import_name_type = "decorated|noprefix|undecorated")]`, `#[link(name = "...", kind = "dylib|static|...")]`, `#[link(name = "...", kind = "dylib|static|...", wasm_import_module = "...", import_name_type = "decorated|noprefix|undecorated")]`, and `#[link(name = "...", wasm_import_module = "...")]`
+  --> $DIR/link-dl.rs:14:1
+   |
+LL | #[link="dl"]
+   | ^^^^^^^^^^^^
+   |
+   = 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 #57571 <https://github.com/rust-lang/rust/issues/57571>
+

tests/ui/attributes/link-dl.allowed.stderr

@@ -0,0 +1,23 @@
+error: valid forms for the attribute are `#[link(name = "...")]`, `#[link(name = "...", import_name_type = "decorated|noprefix|undecorated")]`, `#[link(name = "...", kind = "dylib|static|...")]`, `#[link(name = "...", kind = "dylib|static|...", wasm_import_module = "...", import_name_type = "decorated|noprefix|undecorated")]`, and `#[link(name = "...", wasm_import_module = "...")]`
+  --> $DIR/link-dl.rs:14:1
+   |
+LL | #[link="dl"]
+   | ^^^^^^^^^^^^
+   |
+   = 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 #57571 <https://github.com/rust-lang/rust/issues/57571>
+   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default
+
+error: aborting due to 1 previous error
+
+Future incompatibility report: Future breakage diagnostic:
+error: valid forms for the attribute are `#[link(name = "...")]`, `#[link(name = "...", import_name_type = "decorated|noprefix|undecorated")]`, `#[link(name = "...", kind = "dylib|static|...")]`, `#[link(name = "...", kind = "dylib|static|...", wasm_import_module = "...", import_name_type = "decorated|noprefix|undecorated")]`, and `#[link(name = "...", wasm_import_module = "...")]`
+  --> $DIR/link-dl.rs:14:1
+   |
+LL | #[link="dl"]
+   | ^^^^^^^^^^^^
+   |
+   = 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 #57571 <https://github.com/rust-lang/rust/issues/57571>
+   = note: `#[deny(ill_formed_attribute_input)]` (part of `#[deny(future_incompatible)]`) on by default
+

tests/ui/attributes/link-dl.default_fcw.stderr

@@ -0,0 +1,19 @@
+// Regression test for an issue discovered in https://github.com/rust-lang/rust/pull/143193/files and rediscovered in https://github.com/rust-lang/rust/issues/147254#event-20049906781
+// Malformed #[link] attribute was supposed to be deny-by-default report-in-deps FCW,
+// but accidentally was landed as a hard error.
+//
+// revision `default_fcw` tests that with `ill_formed_attribute_input` (the default) denied,
+// the attribute produces an FCW
+// revision `allowed` tests that with `ill_formed_attribute_input` allowed the test passes
+
+//@ revisions: default_fcw allowed
+//@[allowed] check-pass
+
+#[cfg_attr(allowed, allow(ill_formed_attribute_input))]
+
+#[link="dl"]
+//[default_fcw]~^ ERROR valid forms for the attribute are
+//[default_fcw]~| WARN previously accepted
+extern "C" { }
+
+fn main() {}

tests/ui/attributes/link-dl.rs

@@ -0,0 +1,40 @@
+//@ edition: 2024
+//@ revisions: current next
+//@[next] compile-flags: -Znext-solver
+//@ check-pass
+
+// Regression test for #146813. We previously used a pseudo-canonical
+// query during HIR typeck which caused a query cycle when looking at the
+// witness of a coroutine.
+
+use std::future::Future;
+
+trait ConnectMiddleware {}
+
+trait ConnectHandler: Sized {
+    fn with<M>(self, _: M) -> impl ConnectHandler
+    where
+        M: ConnectMiddleware,
+    {
+        LayeredConnectHandler
+    }
+}
+
+struct LayeredConnectHandler;
+impl ConnectHandler for LayeredConnectHandler {}
+impl<F> ConnectHandler for F where F: FnOnce() {}
+
+impl<F, Fut> ConnectMiddleware for F
+where
+    F: FnOnce() -> Fut,
+    Fut: Future<Output = ()> + Send,
+{
+}
+
+pub async fn fails() {
+    { || {} }
+        .with(async || ())
+        .with(async || ())
+        .with(async || ());
+}
+fn main() {}