Auto merge of #127357 - oli-obk:structureddiag, r=fmease

Remove `StructuredDiag`

follow-up to #127319

This trait was an experiment that didn't pan out.

compiler/rustc_hir_analysis/messages.ftl

@@ -373,10 +373,6 @@ hir_analysis_paren_sugar_attribute = the `#[rustc_paren_sugar]` attribute is a t
 hir_analysis_parenthesized_fn_trait_expansion =
     parenthesized trait syntax expands to `{$expanded_type}`
 
-hir_analysis_pass_to_variadic_function = can't pass `{$ty}` to variadic function
-    .suggestion = cast the value to `{$cast_ty}`
-    .help = cast the value to `{$cast_ty}`
-
 hir_analysis_pattern_type_non_const_range = range patterns must have constant range start and end
 hir_analysis_pattern_type_wild_pat = wildcard patterns are not permitted for pattern types
     .label = this type is the same as the inner type without a pattern

compiler/rustc_hir_analysis/src/errors.rs

@@ -9,6 +9,7 @@ use rustc_middle::ty::Ty;
 use rustc_span::{symbol::Ident, Span, Symbol};
 mod pattern_types;
 pub use pattern_types::*;
+pub mod wrong_number_of_generic_args;
 
 mod precise_captures;
 pub(crate) use precise_captures::*;
@@ -692,20 +693,6 @@ pub(crate) struct TypeOf<'tcx> {
     pub ty: Ty<'tcx>,
 }
 
-#[derive(Diagnostic)]
-#[diag(hir_analysis_pass_to_variadic_function, code = E0617)]
-pub(crate) struct PassToVariadicFunction<'tcx, 'a> {
-    #[primary_span]
-    pub span: Span,
-    pub ty: Ty<'tcx>,
-    pub cast_ty: &'a str,
-    #[suggestion(code = "{replace}", applicability = "machine-applicable")]
-    pub sugg_span: Option<Span>,
-    pub replace: String,
-    #[help]
-    pub help: Option<()>,
-}
-
 #[derive(Diagnostic)]
 #[diag(hir_analysis_invalid_union_field, code = E0740)]
 pub(crate) struct InvalidUnionField {

compiler/rustc_hir_analysis/src/structured_errors/wrong_number_of_generic_args.rs → compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs

@@ -1,8 +1,8 @@
-use crate::structured_errors::StructuredDiag;
-use rustc_errors::{codes::*, pluralize, Applicability, Diag, MultiSpan};
+use rustc_errors::{
+    codes::*, pluralize, Applicability, Diag, Diagnostic, EmissionGuarantee, MultiSpan,
+};
 use rustc_hir as hir;
 use rustc_middle::ty::{self as ty, AssocItems, AssocKind, TyCtxt};
-use rustc_session::Session;
 use rustc_span::def_id::DefId;
 use std::iter;
 
@@ -541,14 +541,8 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
         }
     }
 
-    fn start_diagnostics(&self) -> Diag<'tcx> {
-        let span = self.path_segment.ident.span;
-        let msg = self.create_error_message();
-        self.tcx.dcx().struct_span_err(span, msg).with_code(self.code())
-    }
-
     /// Builds the `expected 1 type argument / supplied 2 type arguments` message.
-    fn notify(&self, err: &mut Diag<'_>) {
+    fn notify(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         let (quantifier, bound) = self.get_quantifier_and_bound();
         let provided_args = self.num_provided_args();
 
@@ -600,7 +594,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
         }
     }
 
-    fn suggest(&self, err: &mut Diag<'_>) {
+    fn suggest(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         debug!(
             "suggest(self.provided {:?}, self.gen_args.span(): {:?})",
             self.num_provided_args(),
@@ -628,7 +622,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
     /// ```text
     /// type Map = HashMap<String>;
     /// ```
-    fn suggest_adding_args(&self, err: &mut Diag<'_>) {
+    fn suggest_adding_args(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         if self.gen_args.parenthesized != hir::GenericArgsParentheses::No {
             return;
         }
@@ -647,7 +641,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
         }
     }
 
-    fn suggest_adding_lifetime_args(&self, err: &mut Diag<'_>) {
+    fn suggest_adding_lifetime_args(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         debug!("suggest_adding_lifetime_args(path_segment: {:?})", self.path_segment);
         let num_missing_args = self.num_missing_lifetime_args();
         let num_params_to_take = num_missing_args;
@@ -701,7 +695,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
         }
     }
 
-    fn suggest_adding_type_and_const_args(&self, err: &mut Diag<'_>) {
+    fn suggest_adding_type_and_const_args(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         let num_missing_args = self.num_missing_type_or_const_args();
         let msg = format!("add missing {} argument{}", self.kind(), pluralize!(num_missing_args));
 
@@ -761,7 +755,10 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
     /// ```compile_fail
     /// Into::into::<Option<_>>(42) // suggests considering `Into::<Option<_>>::into(42)`
     /// ```
-    fn suggest_moving_args_from_assoc_fn_to_trait(&self, err: &mut Diag<'_>) {
+    fn suggest_moving_args_from_assoc_fn_to_trait(
+        &self,
+        err: &mut Diag<'_, impl EmissionGuarantee>,
+    ) {
         let trait_ = match self.tcx.trait_of_item(self.def_id) {
             Some(def_id) => def_id,
             None => return,
@@ -817,7 +814,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
 
     fn suggest_moving_args_from_assoc_fn_to_trait_for_qualified_path(
         &self,
-        err: &mut Diag<'_>,
+        err: &mut Diag<'_, impl EmissionGuarantee>,
         qpath: &'tcx hir::QPath<'tcx>,
         msg: String,
         num_assoc_fn_excess_args: usize,
@@ -850,7 +847,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
 
     fn suggest_moving_args_from_assoc_fn_to_trait_for_method_call(
         &self,
-        err: &mut Diag<'_>,
+        err: &mut Diag<'_, impl EmissionGuarantee>,
         trait_def_id: DefId,
         expr: &'tcx hir::Expr<'tcx>,
         msg: String,
@@ -904,7 +901,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
     /// ```text
     /// type Map = HashMap<String, String, String, String>;
     /// ```
-    fn suggest_removing_args_or_generics(&self, err: &mut Diag<'_>) {
+    fn suggest_removing_args_or_generics(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         let num_provided_lt_args = self.num_provided_lifetime_args();
         let num_provided_type_const_args = self.num_provided_type_or_const_args();
         let unbound_types = self.get_unbound_associated_types();
@@ -922,7 +919,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
         let provided_args_matches_unbound_traits =
             unbound_types.len() == num_redundant_type_or_const_args;
 
-        let remove_lifetime_args = |err: &mut Diag<'_>| {
+        let remove_lifetime_args = |err: &mut Diag<'_, _>| {
             let mut lt_arg_spans = Vec::new();
             let mut found_redundant = false;
             for arg in self.gen_args.args {
@@ -963,7 +960,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
             );
         };
 
-        let remove_type_or_const_args = |err: &mut Diag<'_>| {
+        let remove_type_or_const_args = |err: &mut Diag<'_, _>| {
             let mut gen_arg_spans = Vec::new();
             let mut found_redundant = false;
             for arg in self.gen_args.args {
@@ -1060,7 +1057,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
     }
 
     /// Builds the `type defined here` message.
-    fn show_definition(&self, err: &mut Diag<'_>) {
+    fn show_definition(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         let mut spans: MultiSpan = if let Some(def_span) = self.tcx.def_ident_span(self.def_id) {
             if self.tcx.sess.source_map().is_span_accessible(def_span) {
                 def_span.into()
@@ -1111,7 +1108,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
     }
 
     /// Add note if `impl Trait` is explicitly specified.
-    fn note_synth_provided(&self, err: &mut Diag<'_>) {
+    fn note_synth_provided(&self, err: &mut Diag<'_, impl EmissionGuarantee>) {
         if !self.is_synth_provided() {
             return;
         }
@@ -1120,17 +1117,16 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
     }
 }
 
-impl<'tcx> StructuredDiag<'tcx> for WrongNumberOfGenericArgs<'_, 'tcx> {
-    fn session(&self) -> &Session {
-        self.tcx.sess
-    }
-
-    fn code(&self) -> ErrCode {
-        E0107
-    }
-
-    fn diagnostic_common(&self) -> Diag<'tcx> {
-        let mut err = self.start_diagnostics();
+impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for WrongNumberOfGenericArgs<'_, '_> {
+    fn into_diag(
+        self,
+        dcx: rustc_errors::DiagCtxtHandle<'a>,
+        level: rustc_errors::Level,
+    ) -> Diag<'a, G> {
+        let msg = self.create_error_message();
+        let mut err = Diag::new(dcx, level, msg);
+        err.code(E0107);
+        err.span(self.path_segment.ident.span);
 
         self.notify(&mut err);
         self.suggest(&mut err);

compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs

@@ -1,9 +1,9 @@
 use super::IsMethodCall;
+use crate::errors::wrong_number_of_generic_args::{GenericArgsInfo, WrongNumberOfGenericArgs};
 use crate::hir_ty_lowering::{
     errors::prohibit_assoc_item_constraint, ExplicitLateBound, GenericArgCountMismatch,
     GenericArgCountResult, GenericArgPosition, GenericArgsLowerer,
 };
-use crate::structured_errors::{GenericArgsInfo, StructuredDiag, WrongNumberOfGenericArgs};
 use rustc_ast::ast::ParamKindOrd;
 use rustc_errors::{
     codes::*, struct_span_code_err, Applicability, Diag, ErrorGuaranteed, MultiSpan,
@@ -486,17 +486,15 @@ pub(crate) fn check_generic_arg_count(
             GenericArgsInfo::MissingLifetimes { num_missing_args }
         };
 
-        let reported = WrongNumberOfGenericArgs::new(
+        let reported = tcx.dcx().emit_err(WrongNumberOfGenericArgs::new(
             tcx,
             gen_args_info,
             seg,
             gen_params,
             has_self as usize,
             gen_args,
             def_id,
-        )
-        .diagnostic()
-        .emit();
+        ));
 
         Err(reported)
     };
@@ -573,17 +571,17 @@ pub(crate) fn check_generic_arg_count(
         debug!(?gen_args_info);
 
         let reported = gen_args.has_err().unwrap_or_else(|| {
-            WrongNumberOfGenericArgs::new(
-                tcx,
-                gen_args_info,
-                seg,
-                gen_params,
-                params_offset,
-                gen_args,
-                def_id,
-            )
-            .diagnostic()
-            .emit_unless(all_params_are_binded)
+            tcx.dcx()
+                .create_err(WrongNumberOfGenericArgs::new(
+                    tcx,
+                    gen_args_info,
+                    seg,
+                    gen_params,
+                    params_offset,
+                    gen_args,
+                    def_id,
+                ))
+                .emit_unless(all_params_are_binded)
         });
 
         Err(reported)

compiler/rustc_hir_analysis/src/lib.rs

@@ -92,7 +92,6 @@ mod errors;
 pub mod hir_wf_check;
 mod impl_wf_check;
 mod outlives;
-pub mod structured_errors;
 mod variance;
 
 use rustc_hir as hir;

compiler/rustc_hir_typeck/messages.ftl

@@ -38,6 +38,7 @@ hir_typeck_cast_thin_pointer_to_fat_pointer = cannot cast thin pointer `{$expr_t
 
         For more information about casts, take a look at The Book:
         https://doc.rust-lang.org/reference/expressions/operator-expr.html#type-cast-expressions",
+
 hir_typeck_cast_unknown_pointer = cannot cast {$to ->
     [true] to
     *[false] from
@@ -138,6 +139,11 @@ hir_typeck_option_result_asref = use `{$def_path}::as_ref` to convert `{$expecte
 hir_typeck_option_result_cloned = use `{$def_path}::cloned` to clone the value inside the `{$def_path}`
 hir_typeck_option_result_copied = use `{$def_path}::copied` to copy the value inside the `{$def_path}`
 
+hir_typeck_pass_to_variadic_function = can't pass `{$ty}` to variadic function
+    .suggestion = cast the value to `{$cast_ty}`
+    .help = cast the value to `{$cast_ty}`
+    .teach_help = certain types, like `{$ty}`, must be casted before passing them to a variadic function, because of arcane ABI rules dictated by the C standard
+
 hir_typeck_ptr_cast_add_auto_to_object = adding {$traits_len ->
     [1] an auto trait {$traits}
     *[other] auto traits {$traits}