Auto merge of #127326 - matthiaskrgr:rollup-kz7vd3w, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #123043 (Disable dead variant removal for `#[repr(C)]` enums.)
 - #126405 (Migrate some rustc_builtin_macros to SessionDiagnostic)
 - #127037 (Remove some duplicated tests)
 - #127283 (Reject SmartPointer constructions not serving the purpose)
 - #127301 (Tweak some structured suggestions to be more verbose and accurate)
 - #127307 (Allow to have different types for arguments of `Rustc::remap_path_prefix`)
 - #127309 (jsondocck: add `$FILE` built-in variable)
 - #127314 (Trivial update on tidy bless note)
 - #127319 (Remove a use of `StructuredDiag`, which is incompatible with automatic error tainting and error translations)

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

Author: bors

Diff for: compiler/rustc_abi/src/layout.rs

@@ -186,7 +186,7 @@ pub trait LayoutCalculator {
         let (present_first, present_second) = {
             let mut present_variants = variants
                 .iter_enumerated()
-                .filter_map(|(i, v)| if absent(v) { None } else { Some(i) });
+                .filter_map(|(i, v)| if !repr.c() && absent(v) { None } else { Some(i) });
             (present_variants.next(), present_variants.next())
         };
         let present_first = match present_first {
@@ -621,7 +621,7 @@ where
     let discr_type = repr.discr_type();
     let bits = Integer::from_attr(dl, discr_type).size().bits();
     for (i, mut val) in discriminants {
-        if variants[i].iter().any(|f| f.abi.is_uninhabited()) {
+        if !repr.c() && variants[i].iter().any(|f| f.abi.is_uninhabited()) {
             continue;
         }
         if discr_type.is_signed() {

Diff for: compiler/rustc_abi/src/lib.rs

@@ -1429,7 +1429,7 @@ pub enum Variants<FieldIdx: Idx, VariantIdx: Idx> {
     /// Single enum variants, structs/tuples, unions, and all non-ADTs.
     Single { index: VariantIdx },
 
-    /// Enum-likes with more than one inhabited variant: each variant comes with
+    /// Enum-likes with more than one variant: each variant comes with
     /// a *discriminant* (usually the same as the variant index but the user can
     /// assign explicit discriminant values). That discriminant is encoded
     /// as a *tag* on the machine. The layout of each variant is

Diff for: compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -3757,13 +3757,11 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
         assigned_span: Span,
         err_place: Place<'tcx>,
     ) {
-        let (from_arg, local_decl, local_name) = match err_place.as_local() {
-            Some(local) => (
-                self.body.local_kind(local) == LocalKind::Arg,
-                Some(&self.body.local_decls[local]),
-                self.local_names[local],
-            ),
-            None => (false, None, None),
+        let (from_arg, local_decl) = match err_place.as_local() {
+            Some(local) => {
+                (self.body.local_kind(local) == LocalKind::Arg, Some(&self.body.local_decls[local]))
+            }
+            None => (false, None),
         };
 
         // If root local is initialized immediately (everything apart from let
@@ -3795,13 +3793,12 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
             err.span_label(assigned_span, format!("first assignment to {place_description}"));
         }
         if let Some(decl) = local_decl
-            && let Some(name) = local_name
             && decl.can_be_made_mutable()
         {
-            err.span_suggestion(
-                decl.source_info.span,
+            err.span_suggestion_verbose(
+                decl.source_info.span.shrink_to_lo(),
                 "consider making this binding mutable",
-                format!("mut {name}"),
+                "mut ".to_string(),
                 Applicability::MachineApplicable,
             );
             if !from_arg
@@ -3813,10 +3810,10 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                     }))
                 )
             {
-                err.span_suggestion(
-                    decl.source_info.span,
+                err.span_suggestion_verbose(
+                    decl.source_info.span.shrink_to_lo(),
                     "to modify the original value, take a borrow instead",
-                    format!("ref mut {name}"),
+                    "ref mut ".to_string(),
                     Applicability::MaybeIncorrect,
                 );
             }

Diff for: compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -408,21 +408,21 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                                     fn_decl.implicit_self,
                                     hir::ImplicitSelfKind::RefImm | hir::ImplicitSelfKind::RefMut
                                 ) {
-                                    err.span_suggestion(
-                                        upvar_ident.span,
+                                    err.span_suggestion_verbose(
+                                        upvar_ident.span.shrink_to_lo(),
                                         "consider changing this to be mutable",
-                                        format!("mut {}", upvar_ident.name),
+                                        "mut ",
                                         Applicability::MachineApplicable,
                                     );
                                     break;
                                 }
                             }
                         }
                     } else {
-                        err.span_suggestion(
-                            upvar_ident.span,
+                        err.span_suggestion_verbose(
+                            upvar_ident.span.shrink_to_lo(),
                             "consider changing this to be mutable",
-                            format!("mut {}", upvar_ident.name),
+                            "mut ",
                             Applicability::MachineApplicable,
                         );
                     }
@@ -449,8 +449,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                     .is_ok_and(|snippet| snippet.starts_with("&mut ")) =>
             {
                 err.span_label(span, format!("cannot {act}"));
-                err.span_suggestion(
-                    span,
+                err.span_suggestion_verbose(
+                    span.with_hi(span.lo() + BytePos(5)),
                     "try removing `&mut` here",
                     "",
                     Applicability::MaybeIncorrect,
@@ -755,13 +755,16 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                 pat: hir::Pat { kind: hir::PatKind::Ref(_, _), .. },
                 ..
             }) = node
-            && let Ok(name) =
-                self.infcx.tcx.sess.source_map().span_to_snippet(local_decl.source_info.span)
         {
-            err.span_suggestion(
-                pat_span,
+            err.multipart_suggestion(
                 "consider changing this to be mutable",
-                format!("&(mut {name})"),
+                vec![
+                    (pat_span.until(local_decl.source_info.span), "&(mut ".to_string()),
+                    (
+                        local_decl.source_info.span.shrink_to_hi().with_hi(pat_span.hi()),
+                        ")".to_string(),
+                    ),
+                ],
                 Applicability::MachineApplicable,
             );
             return;

Diff for: compiler/rustc_builtin_macros/messages.ftl

@@ -17,6 +17,9 @@ builtin_macros_asm_expected_other = expected operand, {$is_global_asm ->
     *[false] clobber_abi, options
     }, or additional template string
 
+builtin_macros_asm_expected_string_literal = expected string literal
+    .label = not a string literal
+
 builtin_macros_asm_explicit_register_name = explicit register arguments cannot have names
 
 builtin_macros_asm_mayunwind = asm labels are not allowed with the `may_unwind` option
@@ -25,6 +28,8 @@ builtin_macros_asm_modifier_invalid = asm template modifier must be a single cha
 
 builtin_macros_asm_mutually_exclusive = the `{$opt1}` and `{$opt2}` options are mutually exclusive
 
+builtin_macros_asm_no_matched_argument_name = there is no argument named `{$name}`
+
 builtin_macros_asm_noreturn = asm outputs are not allowed with the `noreturn` option
 
 builtin_macros_asm_opt_already_provided = the `{$symbol}` option was already provided
@@ -228,10 +233,16 @@ builtin_macros_only_one_argument = {$name} takes 1 argument
 
 builtin_macros_proc_macro = `proc-macro` crate types currently cannot export any items other than functions tagged with `#[proc_macro]`, `#[proc_macro_derive]`, or `#[proc_macro_attribute]`
 
+builtin_macros_proc_macro_attribute_only_be_used_on_bare_functions = the `#[{$path}]` attribute may only be used on bare functions
+
+builtin_macros_proc_macro_attribute_only_usable_with_crate_type = the `#[{$path}]` attribute is only usable with crates of the `proc-macro` crate type
+
 builtin_macros_requires_cfg_pattern =
     macro requires a cfg-pattern as an argument
     .label = cfg-pattern required
 
+builtin_macros_source_uitls_expected_item = expected item, found `{$token}`
+
 builtin_macros_takes_no_arguments = {$name} takes no arguments
 
 builtin_macros_test_bad_fn = {$kind} functions cannot be used for tests

Diff for: compiler/rustc_builtin_macros/src/asm.rs

@@ -390,9 +390,7 @@ fn parse_clobber_abi<'a>(p: &mut Parser<'a>, args: &mut AsmArgs) -> PResult<'a,
             }
             Err(opt_lit) => {
                 let span = opt_lit.map_or(p.token.span, |lit| lit.span);
-                let mut err = p.dcx().struct_span_err(span, "expected string literal");
-                err.span_label(span, "not a string literal");
-                return Err(err);
+                return Err(p.dcx().create_err(errors::AsmExpectedStringLiteral { span }));
             }
         };
 
@@ -639,14 +637,13 @@ fn expand_preparsed_asm(
                             match args.named_args.get(&Symbol::intern(name)) {
                                 Some(&idx) => Some(idx),
                                 None => {
-                                    let msg = format!("there is no argument named `{name}`");
                                     let span = arg.position_span;
                                     ecx.dcx()
-                                        .struct_span_err(
-                                            template_span
+                                        .create_err(errors::AsmNoMatchedArgumentName {
+                                            name: name.to_owned(),
+                                            span: template_span
                                                 .from_inner(InnerSpan::new(span.start, span.end)),
-                                            msg,
-                                        )
+                                        })
                                         .emit();
                                     None
                                 }

Diff for: compiler/rustc_builtin_macros/src/deriving/smart_ptr.rs

@@ -3,8 +3,9 @@ use std::mem::swap;
 use ast::HasAttrs;
 use rustc_ast::{
     self as ast, GenericArg, GenericBound, GenericParamKind, ItemKind, MetaItem,
-    TraitBoundModifiers,
+    TraitBoundModifiers, VariantData,
 };
+use rustc_attr as attr;
 use rustc_expand::base::{Annotatable, ExtCtxt};
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
@@ -24,11 +25,43 @@ pub fn expand_deriving_smart_ptr(
     _is_const: bool,
 ) {
     let (name_ident, generics) = if let Annotatable::Item(aitem) = item
-        && let ItemKind::Struct(_, g) = &aitem.kind
+        && let ItemKind::Struct(struct_data, g) = &aitem.kind
     {
+        let is_transparent = aitem.attrs.iter().any(|attr| {
+            attr::find_repr_attrs(cx.sess, attr)
+                .into_iter()
+                .any(|r| matches!(r, attr::ReprTransparent))
+        });
+        if !is_transparent {
+            cx.dcx()
+                .struct_span_err(
+                    span,
+                    "`SmartPointer` can only be derived on `struct`s with `#[repr(transparent)]`",
+                )
+                .emit();
+            return;
+        }
+        if !matches!(
+            struct_data,
+            VariantData::Struct { fields, recovered: _ } | VariantData::Tuple(fields, _)
+                if !fields.is_empty())
+        {
+            cx.dcx()
+                .struct_span_err(
+                    span,
+                    "`SmartPointer` can only be derived on `struct`s with at least one field",
+                )
+                .emit();
+            return;
+        }
         (aitem.ident, g)
     } else {
-        cx.dcx().struct_span_err(span, "`SmartPointer` can only be derived on `struct`s").emit();
+        cx.dcx()
+            .struct_span_err(
+                span,
+                "`SmartPointer` can only be derived on `struct`s with `#[repr(transparent)]`",
+            )
+            .emit();
         return;
     };
 

Diff for: compiler/rustc_builtin_macros/src/errors.rs

@@ -728,6 +728,14 @@ pub(crate) struct AsmExpectedComma {
     pub(crate) span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_expected_string_literal)]
+pub(crate) struct AsmExpectedStringLiteral {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(builtin_macros_asm_underscore_input)]
 pub(crate) struct AsmUnderscoreInput {
@@ -781,6 +789,14 @@ pub(crate) struct AsmNoReturn {
     pub(crate) outputs_sp: Vec<Span>,
 }
 
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_no_matched_argument_name)]
+pub(crate) struct AsmNoMatchedArgumentName {
+    pub(crate) name: String,
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(builtin_macros_asm_mayunwind)]
 pub(crate) struct AsmMayUnwind {
@@ -872,3 +888,27 @@ pub(crate) struct TakesNoArguments<'a> {
     pub span: Span,
     pub name: &'a str,
 }
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_proc_macro_attribute_only_be_used_on_bare_functions)]
+pub(crate) struct AttributeOnlyBeUsedOnBareFunctions<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub path: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_proc_macro_attribute_only_usable_with_crate_type)]
+pub(crate) struct AttributeOnlyUsableWithCrateType<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub path: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_source_uitls_expected_item)]
+pub(crate) struct ExpectedItem<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub token: &'a str,
+}

Diff for: compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -214,12 +214,12 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
         };
 
         if !is_fn {
-            let msg = format!(
-                "the `#[{}]` attribute may only be used on bare functions",
-                pprust::path_to_string(&attr.get_normal_item().path),
-            );
-
-            self.dcx.span_err(attr.span, msg);
+            self.dcx
+                .create_err(errors::AttributeOnlyBeUsedOnBareFunctions {
+                    span: attr.span,
+                    path: &pprust::path_to_string(&attr.get_normal_item().path),
+                })
+                .emit();
             return;
         }
 
@@ -228,12 +228,12 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
         }
 
         if !self.is_proc_macro_crate {
-            let msg = format!(
-                "the `#[{}]` attribute is only usable with crates of the `proc-macro` crate type",
-                pprust::path_to_string(&attr.get_normal_item().path),
-            );
-
-            self.dcx.span_err(attr.span, msg);
+            self.dcx
+                .create_err(errors::AttributeOnlyUsableWithCrateType {
+                    span: attr.span,
+                    path: &pprust::path_to_string(&attr.get_normal_item().path),
+                })
+                .emit();
             return;
         }
 

Diff for: compiler/rustc_builtin_macros/src/source_util.rs

@@ -1,3 +1,4 @@
+use crate::errors;
 use crate::util::{
     check_zero_tts, get_single_str_from_tts, get_single_str_spanned_from_tts, parse_expr,
 };
@@ -165,9 +166,13 @@ pub(crate) fn expand_include<'cx>(
                     Ok(Some(item)) => ret.push(item),
                     Ok(None) => {
                         if self.p.token != token::Eof {
-                            let token = pprust::token_to_string(&self.p.token);
-                            let msg = format!("expected item, found `{token}`");
-                            self.p.dcx().span_err(self.p.token.span, msg);
+                            self.p
+                                .dcx()
+                                .create_err(errors::ExpectedItem {
+                                    span: self.p.token.span,
+                                    token: &pprust::token_to_string(&self.p.token),
+                                })
+                                .emit();
                         }
 
                         break;