Auto merge of #84840 - Dylan-DPC:rollup-uzk7w0h, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #84072 (Allow setting `target_family` to multiple values, and implement `target_family="wasm"`)
 - #84744 (Add ErrorKind::OutOfMemory)
 - #84784 (Add help message to suggest const for unused type param)
 - #84811 (RustDoc: Fix bounds linking trait.Foo instead of traitalias.Foo)
 - #84818 (suggestion for unit enum variant when matched with a patern)
 - #84832 (Do not print visibility in external traits)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -819,6 +819,19 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
             _ => false,
         };
 
+        let find_span = |source: &PathSource<'_>, err: &mut DiagnosticBuilder<'_>| {
+            match source {
+                PathSource::Expr(Some(Expr { span, kind: ExprKind::Call(_, _), .. }))
+                | PathSource::TupleStruct(span, _) => {
+                    // We want the main underline to cover the suggested code as well for
+                    // cleaner output.
+                    err.set_span(*span);
+                    *span
+                }
+                _ => span,
+            }
+        };
+
         let mut bad_struct_syntax_suggestion = |def_id: DefId| {
             let (followed_by_brace, closing_brace) = self.followed_by_brace(span);
 
@@ -862,18 +875,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                     }
                 }
                 PathSource::Expr(_) | PathSource::TupleStruct(..) | PathSource::Pat => {
-                    let span = match &source {
-                        PathSource::Expr(Some(Expr {
-                            span, kind: ExprKind::Call(_, _), ..
-                        }))
-                        | PathSource::TupleStruct(span, _) => {
-                            // We want the main underline to cover the suggested code as well for
-                            // cleaner output.
-                            err.set_span(*span);
-                            *span
-                        }
-                        _ => span,
-                    };
+                    let span = find_span(&source, err);
                     if let Some(span) = self.def_span(def_id) {
                         err.span_label(span, &format!("`{}` defined here", path_str));
                     }
@@ -1047,6 +1049,23 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
             ) if ns == ValueNS => {
                 bad_struct_syntax_suggestion(def_id);
             }
+            (Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id), _) if ns == ValueNS => {
+                match source {
+                    PathSource::Expr(_) | PathSource::TupleStruct(..) | PathSource::Pat => {
+                        let span = find_span(&source, err);
+                        if let Some(span) = self.def_span(def_id) {
+                            err.span_label(span, &format!("`{}` defined here", path_str));
+                        }
+                        err.span_suggestion(
+                            span,
+                            &format!("use this syntax instead"),
+                            format!("{path_str}"),
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
+                    _ => return false,
+                }
+            }
             (Res::Def(DefKind::Ctor(_, CtorKind::Fn), def_id), _) if ns == ValueNS => {
                 if let Some(span) = self.def_span(def_id) {
                     err.span_label(span, &format!("`{}` defined here", path_str));

compiler/rustc_session/src/config.rs

@@ -816,7 +816,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
     ret.reserve(6); // the minimum number of insertions
     // Target bindings.
     ret.insert((sym::target_os, Some(Symbol::intern(os))));
-    if let Some(ref fam) = sess.target.os_family {
+    for fam in &sess.target.families {
         ret.insert((sym::target_family, Some(Symbol::intern(fam))));
         if fam == "windows" {
             ret.insert((sym::windows, None));

compiler/rustc_target/src/spec/apple_base.rs

@@ -23,7 +23,7 @@ pub fn opts(os: &str) -> TargetOptions {
         function_sections: false,
         dynamic_linking: true,
         executables: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         is_like_osx: true,
         dwarf_version: Some(2),
         has_rpath: true,

compiler/rustc_target/src/spec/dragonfly_base.rs

@@ -5,7 +5,7 @@ pub fn opts() -> TargetOptions {
         os: "dragonfly".to_string(),
         dynamic_linking: true,
         executables: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         linker_is_gnu: true,
         has_rpath: true,
         position_independent_executables: true,

compiler/rustc_target/src/spec/freebsd_base.rs

@@ -5,7 +5,7 @@ pub fn opts() -> TargetOptions {
         os: "freebsd".to_string(),
         dynamic_linking: true,
         executables: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         linker_is_gnu: true,
         has_rpath: true,
         position_independent_executables: true,

compiler/rustc_target/src/spec/fuchsia_base.rs

@@ -25,7 +25,7 @@ pub fn opts() -> TargetOptions {
         linker: Some("rust-lld".to_owned()),
         dynamic_linking: true,
         executables: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         is_like_fuchsia: true,
         linker_is_gnu: true,
         pre_link_args,

compiler/rustc_target/src/spec/haiku_base.rs

@@ -5,7 +5,7 @@ pub fn opts() -> TargetOptions {
         os: "haiku".to_string(),
         dynamic_linking: true,
         executables: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         relro_level: RelroLevel::Full,
         linker_is_gnu: true,
         ..Default::default()

compiler/rustc_target/src/spec/illumos_base.rs

@@ -20,7 +20,7 @@ pub fn opts() -> TargetOptions {
         dynamic_linking: true,
         executables: true,
         has_rpath: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         is_like_solaris: true,
         limit_rdylib_exports: false, // Linker doesn't support this
         eliminate_frame_pointer: false,

compiler/rustc_target/src/spec/l4re_base.rs

@@ -20,7 +20,7 @@ pub fn opts() -> TargetOptions {
         executables: true,
         panic_strategy: PanicStrategy::Abort,
         linker: Some("ld".to_string()),
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         ..Default::default()
     }
 }

compiler/rustc_target/src/spec/linux_base.rs

@@ -5,7 +5,7 @@ pub fn opts() -> TargetOptions {
         os: "linux".to_string(),
         dynamic_linking: true,
         executables: true,
-        os_family: Some("unix".to_string()),
+        families: vec!["unix".to_string()],
         linker_is_gnu: true,
         has_rpath: true,
         position_independent_executables: true,