Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

12 files changed, 102 insertions, 169 deletions

diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic.rs b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
index 684835d8c..9ff944864 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
@@ -39,10 +39,8 @@ impl<'a> DiagnosticDerive<'a> {
             let init = match builder.slug.value_ref() {
                 None => {
                     span_err(builder.span, "diagnostic slug not specified")
-                        .help(format!(
-                            "specify the slug as the first argument to the `#[diag(...)]` \
-                            attribute, such as `#[diag(hir_analysis_example_error)]`",
-                        ))
+                        .help("specify the slug as the first argument to the `#[diag(...)]` \
+                            attribute, such as `#[diag(hir_analysis_example_error)]`")
                         .emit();
                     return DiagnosticDeriveError::ErrorHandled.to_compile_error();
                 }
@@ -133,10 +131,8 @@ impl<'a> LintDiagnosticDerive<'a> {
             match builder.slug.value_ref() {
                 None => {
                     span_err(builder.span, "diagnostic slug not specified")
-                        .help(format!(
-                            "specify the slug as the first argument to the attribute, such as \
-                            `#[diag(compiletest_example)]`",
-                        ))
+                        .help("specify the slug as the first argument to the attribute, such as \
+                            `#[diag(compiletest_example)]`")
                         .emit();
                     DiagnosticDeriveError::ErrorHandled.to_compile_error()
                 }
@@ -192,7 +188,7 @@ impl Mismatch {
         let crate_name = std::env::var("CARGO_CRATE_NAME").ok()?;
 
         // If we're not in a "rustc_" crate, bail.
-        let Some(("rustc", slug_prefix)) = crate_name.split_once("_") else { return None };
+        let Some(("rustc", slug_prefix)) = crate_name.split_once('_') else { return None };
 
         let slug_name = slug.segments.first()?.ident.to_string();
         if !slug_name.starts_with(slug_prefix) {
diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs b/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
index 9f2ac5112..e405462bb 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
@@ -372,45 +372,36 @@ impl<'a> DiagnosticDeriveVariantBuilder<'a> {
                 }
             }
             (Meta::Path(_), "subdiagnostic") => {
-                return Ok(quote! { #diag.subdiagnostic(#binding); });
-            }
-            (Meta::NameValue(_), "subdiagnostic") => {
-                throw_invalid_attr!(attr, &meta, |diag| {
-                    diag.help("`eager` is the only supported nested attribute for `subdiagnostic`")
-                })
+                if FieldInnerTy::from_type(&info.binding.ast().ty).will_iterate() {
+                    let DiagnosticDeriveKind::Diagnostic { handler } = &self.parent.kind else {
+                        // No eager translation for lints.
+                        return Ok(quote! { #diag.subdiagnostic(#binding); });
+                    };
+                    return Ok(quote! { #diag.eager_subdiagnostic(#handler, #binding); });
+                } else {
+                    return Ok(quote! { #diag.subdiagnostic(#binding); });
+                }
             }
             (Meta::List(MetaList { ref nested, .. }), "subdiagnostic") => {
-                if nested.len() != 1 {
+                if nested.len() == 1
+                    && let Some(NestedMeta::Meta(Meta::Path(path))) = nested.first()
+                    && path.is_ident("eager") {
+                        let handler = match &self.parent.kind {
+                            DiagnosticDeriveKind::Diagnostic { handler } => handler,
+                            DiagnosticDeriveKind::LintDiagnostic => {
+                                throw_invalid_attr!(attr, &meta, |diag| {
+                                    diag.help("eager subdiagnostics are not supported on lints")
+                                })
+                            }
+                        };
+                        return Ok(quote! { #diag.eager_subdiagnostic(#handler, #binding); });
+                } else {
                     throw_invalid_attr!(attr, &meta, |diag| {
                         diag.help(
                             "`eager` is the only supported nested attribute for `subdiagnostic`",
                         )
                     })
                 }
-
-                let handler = match &self.parent.kind {
-                    DiagnosticDeriveKind::Diagnostic { handler } => handler,
-                    DiagnosticDeriveKind::LintDiagnostic => {
-                        throw_invalid_attr!(attr, &meta, |diag| {
-                            diag.help("eager subdiagnostics are not supported on lints")
-                        })
-                    }
-                };
-
-                let nested_attr = nested.first().expect("pop failed for single element list");
-                match nested_attr {
-                    NestedMeta::Meta(meta @ Meta::Path(_))
-                        if meta.path().segments.last().unwrap().ident.to_string().as_str()
-                            == "eager" =>
-                    {
-                        return Ok(quote! { #diag.eager_subdiagnostic(#handler, #binding); });
-                    }
-                    _ => {
-                        throw_invalid_nested_attr!(attr, nested_attr, |diag| {
-                            diag.help("`eager` is the only supported nested attribute for `subdiagnostic`")
-                        })
-                    }
-                }
             }
             _ => (),
         }
diff --git a/compiler/rustc_macros/src/diagnostics/error.rs b/compiler/rustc_macros/src/diagnostics/error.rs
index 4612f54e4..2d62d5931 100644
--- a/compiler/rustc_macros/src/diagnostics/error.rs
+++ b/compiler/rustc_macros/src/diagnostics/error.rs
@@ -76,11 +76,11 @@ pub(crate) fn invalid_attr(attr: &Attribute, meta: &Meta) -> Diagnostic {
     let span = attr.span().unwrap();
     let path = path_to_string(&attr.path);
     match meta {
-        Meta::Path(_) => span_err(span, &format!("`#[{}]` is not a valid attribute", path)),
+        Meta::Path(_) => span_err(span, &format!("`#[{path}]` is not a valid attribute")),
         Meta::NameValue(_) => {
-            span_err(span, &format!("`#[{} = ...]` is not a valid attribute", path))
+            span_err(span, &format!("`#[{path} = ...]` is not a valid attribute"))
         }
-        Meta::List(_) => span_err(span, &format!("`#[{}(...)]` is not a valid attribute", path)),
+        Meta::List(_) => span_err(span, &format!("`#[{path}(...)]` is not a valid attribute")),
     }
 }
 
@@ -107,7 +107,7 @@ pub(crate) fn invalid_nested_attr(attr: &Attribute, nested: &NestedMeta) -> Diag
     let meta = match nested {
         syn::NestedMeta::Meta(meta) => meta,
         syn::NestedMeta::Lit(_) => {
-            return span_err(span, &format!("`#[{}(\"...\")]` is not a valid attribute", name));
+            return span_err(span, &format!("`#[{name}(\"...\")]` is not a valid attribute"));
         }
     };
 
@@ -115,13 +115,11 @@ pub(crate) fn invalid_nested_attr(attr: &Attribute, nested: &NestedMeta) -> Diag
     let path = path_to_string(meta.path());
     match meta {
         Meta::NameValue(..) => {
-            span_err(span, &format!("`#[{}({} = ...)]` is not a valid attribute", name, path))
-        }
-        Meta::Path(..) => {
-            span_err(span, &format!("`#[{}({})]` is not a valid attribute", name, path))
+            span_err(span, &format!("`#[{name}({path} = ...)]` is not a valid attribute"))
         }
+        Meta::Path(..) => span_err(span, &format!("`#[{name}({path})]` is not a valid attribute")),
         Meta::List(..) => {
-            span_err(span, &format!("`#[{}({}(...))]` is not a valid attribute", name, path))
+            span_err(span, &format!("`#[{name}({path}(...))]` is not a valid attribute"))
         }
     }
 }
diff --git a/compiler/rustc_macros/src/diagnostics/fluent.rs b/compiler/rustc_macros/src/diagnostics/fluent.rs
index 3e447c94e..32338f9df 100644
--- a/compiler/rustc_macros/src/diagnostics/fluent.rs
+++ b/compiler/rustc_macros/src/diagnostics/fluent.rs
@@ -178,7 +178,7 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
                         opt: Default::default(),
                     };
                     let dl = DisplayList::from(snippet);
-                    eprintln!("{}\n", dl);
+                    eprintln!("{dl}\n");
                 }
                 continue;
             }
@@ -265,7 +265,7 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
                         Diagnostic::spanned(
                             path_span,
                             Level::Error,
-                            format!("overrides existing {}: `{}`", kind, id),
+                            format!("overrides existing {kind}: `{id}`"),
                         )
                         .span_help(previous_defns[&id], "previously defined in this resource")
                         .emit();
diff --git a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
index 446aebe4f..baffd3cec 100644
--- a/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/subdiagnostic.rs
@@ -29,7 +29,7 @@ impl SubdiagnosticDeriveBuilder {
         Self { diag, f }
     }
 
-    pub(crate) fn into_tokens<'a>(self, mut structure: Structure<'a>) -> TokenStream {
+    pub(crate) fn into_tokens(self, mut structure: Structure<'_>) -> TokenStream {
         let implementation = {
             let ast = structure.ast();
             let span = ast.span().unwrap();
@@ -198,8 +198,7 @@ impl<'parent, 'a> SubdiagnosticDeriveVariantBuilder<'parent, 'a> {
                 throw_span_err!(
                     attr.span().unwrap(),
                     &format!(
-                        "diagnostic slug must be first argument of a `#[{}(...)]` attribute",
-                        name
+                        "diagnostic slug must be first argument of a `#[{name}(...)]` attribute"
                     )
                 );
             };
diff --git a/compiler/rustc_macros/src/diagnostics/utils.rs b/compiler/rustc_macros/src/diagnostics/utils.rs
index da9023352..6f52a3de1 100644
--- a/compiler/rustc_macros/src/diagnostics/utils.rs
+++ b/compiler/rustc_macros/src/diagnostics/utils.rs
@@ -322,7 +322,7 @@ pub(crate) trait HasFieldMap {
                 None => {
                     span_err(
                         span.unwrap(),
-                        &format!("`{}` doesn't refer to a field on this type", field),
+                        &format!("`{field}` doesn't refer to a field on this type"),
                     )
                     .emit();
                     quote! {
@@ -385,7 +385,7 @@ impl quote::ToTokens for Applicability {
 
 /// Build the mapping of field names to fields. This allows attributes to peek values from
 /// other fields.
-pub(super) fn build_field_mapping<'v>(variant: &VariantInfo<'v>) -> HashMap<String, TokenStream> {
+pub(super) fn build_field_mapping(variant: &VariantInfo<'_>) -> HashMap<String, TokenStream> {
     let mut fields_map = FieldMap::new();
     for binding in variant.bindings() {
         if let Some(ident) = &binding.ast().ident {
@@ -603,8 +603,7 @@ impl SubdiagnosticKind {
                     if suggestion_kind != SuggestionKind::Normal {
                         invalid_attr(attr, &meta)
                             .help(format!(
-                                r#"Use `#[suggestion(..., style = "{}")]` instead"#,
-                                suggestion_kind
+                                r#"Use `#[suggestion(..., style = "{suggestion_kind}")]` instead"#
                             ))
                             .emit();
                     }
@@ -621,8 +620,7 @@ impl SubdiagnosticKind {
                     if suggestion_kind != SuggestionKind::Normal {
                         invalid_attr(attr, &meta)
                             .help(format!(
-                                r#"Use `#[multipart_suggestion(..., style = "{}")]` instead"#,
-                                suggestion_kind
+                                r#"Use `#[multipart_suggestion(..., style = "{suggestion_kind}")]` instead"#
                             ))
                             .emit();
                     }
diff --git a/compiler/rustc_macros/src/lib.rs b/compiler/rustc_macros/src/lib.rs
index ac916bb60..bb3722fe1 100644
--- a/compiler/rustc_macros/src/lib.rs
+++ b/compiler/rustc_macros/src/lib.rs
@@ -1,5 +1,6 @@
 #![feature(allow_internal_unstable)]
 #![feature(if_let_guard)]
+#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]
diff --git a/compiler/rustc_macros/src/newtype.rs b/compiler/rustc_macros/src/newtype.rs
index fd3f52251..89ea89cf5 100644
--- a/compiler/rustc_macros/src/newtype.rs
+++ b/compiler/rustc_macros/src/newtype.rs
@@ -1,35 +1,15 @@
 use proc_macro2::{Span, TokenStream};
 use quote::quote;
 use syn::parse::*;
-use syn::punctuated::Punctuated;
 use syn::*;
 
-mod kw {
-    syn::custom_keyword!(derive);
-    syn::custom_keyword!(DEBUG_FORMAT);
-    syn::custom_keyword!(MAX);
-    syn::custom_keyword!(ENCODABLE);
-    syn::custom_keyword!(custom);
-    syn::custom_keyword!(ORD_IMPL);
-}
-
-#[derive(Debug)]
-enum DebugFormat {
-    // The user will provide a custom `Debug` impl, so we shouldn't generate
-    // one
-    Custom,
-    // Use the specified format string in the generated `Debug` impl
-    // By default, this is "{}"
-    Format(String),
-}
-
 // We parse the input and emit the output in a single step.
 // This field stores the final macro output
 struct Newtype(TokenStream);
 
 impl Parse for Newtype {
     fn parse(input: ParseStream<'_>) -> Result<Self> {
-        let attrs = input.call(Attribute::parse_outer)?;
+        let mut attrs = input.call(Attribute::parse_outer)?;
         let vis: Visibility = input.parse()?;
         input.parse::<Token![struct]>()?;
         let name: Ident = input.parse()?;
@@ -39,93 +19,68 @@ impl Parse for Newtype {
 
         // Any additional `#[derive]` macro paths to apply
         let mut derive_paths: Vec<Path> = Vec::new();
-        let mut debug_format: Option<DebugFormat> = None;
+        let mut debug_format: Option<Lit> = None;
         let mut max = None;
         let mut consts = Vec::new();
         let mut encodable = true;
         let mut ord = true;
 
-        // Parse an optional trailing comma
-        let try_comma = || -> Result<()> {
-            if body.lookahead1().peek(Token![,]) {
-                body.parse::<Token![,]>()?;
-            }
-            Ok(())
-        };
-
-        if body.lookahead1().peek(Token![..]) {
-            body.parse::<Token![..]>()?;
-        } else {
-            loop {
-                if body.lookahead1().peek(kw::derive) {
-                    body.parse::<kw::derive>()?;
-                    let derives;
-                    bracketed!(derives in body);
-                    let derives: Punctuated<Path, Token![,]> =
-                        derives.parse_terminated(Path::parse)?;
-                    try_comma()?;
-                    derive_paths.extend(derives);
-                    continue;
-                }
-                if body.lookahead1().peek(kw::DEBUG_FORMAT) {
-                    body.parse::<kw::DEBUG_FORMAT>()?;
-                    body.parse::<Token![=]>()?;
-                    let new_debug_format = if body.lookahead1().peek(kw::custom) {
-                        body.parse::<kw::custom>()?;
-                        DebugFormat::Custom
-                    } else {
-                        let format_str: LitStr = body.parse()?;
-                        DebugFormat::Format(format_str.value())
-                    };
-                    try_comma()?;
-                    if let Some(old) = debug_format.replace(new_debug_format) {
-                        panic!("Specified multiple debug format options: {:?}", old);
-                    }
-                    continue;
-                }
-                if body.lookahead1().peek(kw::MAX) {
-                    body.parse::<kw::MAX>()?;
-                    body.parse::<Token![=]>()?;
-                    let val: Lit = body.parse()?;
-                    try_comma()?;
-                    if let Some(old) = max.replace(val) {
-                        panic!("Specified multiple MAX: {:?}", old);
-                    }
-                    continue;
-                }
-                if body.lookahead1().peek(kw::ENCODABLE) {
-                    body.parse::<kw::ENCODABLE>()?;
-                    body.parse::<Token![=]>()?;
-                    body.parse::<kw::custom>()?;
-                    try_comma()?;
+        attrs.retain(|attr| match attr.path.get_ident() {
+            Some(ident) => match &*ident.to_string() {
+                "custom_encodable" => {
                     encodable = false;
-                    continue;
+                    false
                 }
-                if body.lookahead1().peek(kw::ORD_IMPL) {
-                    body.parse::<kw::ORD_IMPL>()?;
-                    body.parse::<Token![=]>()?;
-                    body.parse::<kw::custom>()?;
+                "no_ord_impl" => {
                     ord = false;
-                    continue;
+                    false
                 }
+                "max" => {
+                    let Ok(Meta::NameValue(literal) )= attr.parse_meta() else {
+                        panic!("#[max = NUMBER] attribute requires max value");
+                    };
+
+                    if let Some(old) = max.replace(literal.lit) {
+                        panic!("Specified multiple max: {old:?}");
+                    }
 
-                // We've parsed everything that the user provided, so we're done
-                if body.is_empty() {
-                    break;
+                    false
                 }
+                "debug_format" => {
+                    let Ok(Meta::NameValue(literal) )= attr.parse_meta() else {
+                        panic!("#[debug_format = FMT] attribute requires a format");
+                    };
 
-                // Otherwise, we are parsing a user-defined constant
-                let const_attrs = body.call(Attribute::parse_outer)?;
-                body.parse::<Token![const]>()?;
-                let const_name: Ident = body.parse()?;
-                body.parse::<Token![=]>()?;
-                let const_val: Expr = body.parse()?;
-                try_comma()?;
-                consts.push(quote! { #(#const_attrs)* #vis const #const_name: #name = #name::from_u32(#const_val); });
+                    if let Some(old) = debug_format.replace(literal.lit) {
+                        panic!("Specified multiple debug format options: {old:?}");
+                    }
+
+                    false
+                }
+                _ => true,
+            },
+            _ => true,
+        });
+
+        loop {
+            // We've parsed everything that the user provided, so we're done
+            if body.is_empty() {
+                break;
             }
+
+            // Otherwise, we are parsing a user-defined constant
+            let const_attrs = body.call(Attribute::parse_outer)?;
+            body.parse::<Token![const]>()?;
+            let const_name: Ident = body.parse()?;
+            body.parse::<Token![=]>()?;
+            let const_val: Expr = body.parse()?;
+            body.parse::<Token![;]>()?;
+            consts.push(quote! { #(#const_attrs)* #vis const #const_name: #name = #name::from_u32(#const_val); });
         }
 
-        let debug_format = debug_format.unwrap_or(DebugFormat::Format("{}".to_string()));
+        let debug_format =
+            debug_format.unwrap_or_else(|| Lit::Str(LitStr::new("{}", Span::call_site())));
+
         // shave off 256 indices at the end to allow space for packing these indices into enums
         let max = max.unwrap_or_else(|| Lit::Int(LitInt::new("0xFFFF_FF00", Span::call_site())));
 
@@ -180,18 +135,14 @@ impl Parse for Newtype {
             quote! {}
         };
 
-        let debug_impl = match debug_format {
-            DebugFormat::Custom => quote! {},
-            DebugFormat::Format(format) => {
-                quote! {
-                    impl ::std::fmt::Debug for #name {
-                        fn fmt(&self, fmt: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
-                            write!(fmt, #format, self.as_u32())
-                        }
-                    }
+        let debug_impl = quote! {
+            impl ::std::fmt::Debug for #name {
+                fn fmt(&self, fmt: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
+                    write!(fmt, #debug_format, self.as_u32())
                 }
             }
         };
+
         let spec_partial_eq_impl = if let Lit::Int(max) = &max {
             if let Ok(max_val) = max.base10_parse::<u32>() {
                 quote! {
diff --git a/compiler/rustc_macros/src/query.rs b/compiler/rustc_macros/src/query.rs
index 789d83a0d..08e42a8a0 100644
--- a/compiler/rustc_macros/src/query.rs
+++ b/compiler/rustc_macros/src/query.rs
@@ -239,7 +239,7 @@ fn doc_comment_from_desc(list: &Punctuated<Expr, token::Comma>) -> Result<Attrib
             .unwrap();
         },
     );
-    let doc_string = format!("[query description - consider adding a doc-comment!] {}", doc_string);
+    let doc_string = format!("[query description - consider adding a doc-comment!] {doc_string}");
     Ok(parse_quote! { #[doc = #doc_string] })
 }
 
diff --git a/compiler/rustc_macros/src/symbols.rs b/compiler/rustc_macros/src/symbols.rs
index 92590c33b..04facbf65 100644
--- a/compiler/rustc_macros/src/symbols.rs
+++ b/compiler/rustc_macros/src/symbols.rs
@@ -134,7 +134,7 @@ fn symbols_with_errors(input: TokenStream) -> (TokenStream, Vec<syn::Error>) {
 
     let mut check_dup = |span: Span, str: &str, errors: &mut Errors| {
         if let Some(prev_span) = keys.get(str) {
-            errors.error(span, format!("Symbol `{}` is duplicated", str));
+            errors.error(span, format!("Symbol `{str}` is duplicated"));
             errors.error(*prev_span, "location of previous definition".to_string());
         } else {
             keys.insert(str.to_string(), span);
@@ -144,8 +144,8 @@ fn symbols_with_errors(input: TokenStream) -> (TokenStream, Vec<syn::Error>) {
     let mut check_order = |span: Span, str: &str, errors: &mut Errors| {
         if let Some((prev_span, ref prev_str)) = prev_key {
             if str < prev_str {
-                errors.error(span, format!("Symbol `{}` must precede `{}`", str, prev_str));
-                errors.error(prev_span, format!("location of previous symbol `{}`", prev_str));
+                errors.error(span, format!("Symbol `{str}` must precede `{prev_str}`"));
+                errors.error(prev_span, format!("location of previous symbol `{prev_str}`"));
             }
         }
         prev_key = Some((span, str.to_string()));
diff --git a/compiler/rustc_macros/src/symbols/tests.rs b/compiler/rustc_macros/src/symbols/tests.rs
index 842d2a977..bd0c08a53 100644
--- a/compiler/rustc_macros/src/symbols/tests.rs
+++ b/compiler/rustc_macros/src/symbols/tests.rs
@@ -16,14 +16,13 @@ fn test_symbols() {
     let m: &syn::ItemMacro = file
         .items
         .iter()
-        .filter_map(|i| {
+        .find_map(|i| {
             if let syn::Item::Macro(m) = i {
                 if m.mac.path == symbols_path { Some(m) } else { None }
             } else {
                 None
             }
         })
-        .next()
         .expect("did not find `symbols!` macro invocation.");
 
     let body_tokens = m.mac.tokens.clone();
diff --git a/compiler/rustc_macros/src/type_visitable.rs b/compiler/rustc_macros/src/type_visitable.rs
index 14e6aa6e0..1f95661ce 100644
--- a/compiler/rustc_macros/src/type_visitable.rs
+++ b/compiler/rustc_macros/src/type_visitable.rs
@@ -26,7 +26,7 @@ pub fn type_visitable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
                 __visitor: &mut __V
             ) -> ::std::ops::ControlFlow<__V::BreakTy> {
                 match *self { #body_visit }
-                ::std::ops::ControlFlow::CONTINUE
+                ::std::ops::ControlFlow::Continue(())
             }
         },
     )