Make spans a bit better

compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs

@@ -9,7 +9,7 @@ use crate::diagnostics::utils::{
     FieldInnerTy, FieldMap, HasFieldMap, SetOnce, SpannedOption, SubdiagnosticKind,
 };
 use proc_macro2::{Ident, Span, TokenStream};
-use quote::{format_ident, quote};
+use quote::{format_ident, quote, quote_spanned};
 use syn::Token;
 use syn::{parse_quote, spanned::Spanned, Attribute, Meta, Path, Type};
 use synstructure::{BindingInfo, Structure, VariantInfo};
@@ -251,7 +251,8 @@ impl<'a> DiagnosticDeriveVariantBuilder<'a> {
         let diag = &self.parent.diag;
 
         let field = binding_info.ast();
-        let field_binding = &binding_info.binding;
+        let mut field_binding = binding_info.binding.clone();
+        field_binding.set_span(field.ty.span());
 
         let ident = field.ident.as_ref().unwrap();
         let ident = format_ident!("{}", ident); // strip `r#` prefix, if present
@@ -284,9 +285,9 @@ impl<'a> DiagnosticDeriveVariantBuilder<'a> {
                     name == "primary_span" && matches!(inner_ty, FieldInnerTy::Vec(_));
                 let (binding, needs_destructure) = if needs_clone {
                     // `primary_span` can accept a `Vec<Span>` so don't destructure that.
-                    (quote! { #field_binding.clone() }, false)
+                    (quote_spanned! {inner_ty.span()=> #field_binding.clone() }, false)
                 } else {
-                    (quote! { #field_binding }, true)
+                    (quote_spanned! {inner_ty.span()=> #field_binding }, true)
                 };
 
                 let generated_code = self

compiler/rustc_macros/src/diagnostics/subdiagnostic.rs

@@ -209,18 +209,20 @@ impl<'parent, 'a> SubdiagnosticDeriveVariantBuilder<'parent, 'a> {
     }
 
     /// Generates the code for a field with no attributes.
-    fn generate_field_set_arg(&mut self, binding: &BindingInfo<'_>) -> TokenStream {
-        let ast = binding.ast();
-
+    fn generate_field_set_arg(&mut self, binding_info: &BindingInfo<'_>) -> TokenStream {
         let diag = &self.parent.diag;
-        let ident = ast.ident.as_ref().unwrap();
-        // strip `r#` prefix, if present
-        let ident = format_ident!("{}", ident);
+
+        let field = binding_info.ast();
+        let mut field_binding = binding_info.binding.clone();
+        field_binding.set_span(field.ty.span());
+
+        let ident = field.ident.as_ref().unwrap();
+        let ident = format_ident!("{}", ident); // strip `r#` prefix, if present
 
         quote! {
             #diag.set_arg(
                 stringify!(#ident),
-                #binding
+                #field_binding
             );
         }
     }
@@ -397,7 +399,8 @@ impl<'parent, 'a> SubdiagnosticDeriveVariantBuilder<'parent, 'a> {
         clone_suggestion_code: bool,
     ) -> Result<TokenStream, DiagnosticDeriveError> {
         let span = attr.span().unwrap();
-        let ident = &list.path.segments.last().unwrap().ident;
+        let mut ident = list.path.segments.last().unwrap().ident.clone();
+        ident.set_span(info.ty.span());
         let name = ident.to_string();
         let name = name.as_str();
 
@@ -496,7 +499,7 @@ impl<'parent, 'a> SubdiagnosticDeriveVariantBuilder<'parent, 'a> {
             .variant
             .bindings()
             .iter()
-            .filter(|binding| !binding.ast().attrs.is_empty())
+            .filter(|binding| !should_generate_set_arg(binding.ast()))
             .map(|binding| self.generate_field_attr_code(binding, kind_stats))
             .collect();
 

compiler/rustc_macros/src/diagnostics/utils.rs

@@ -207,6 +207,12 @@ impl<'ty> FieldInnerTy<'ty> {
             FieldInnerTy::Plain(..) => quote! { #inner },
         }
     }
+
+    pub fn span(&self) -> proc_macro2::Span {
+        match self {
+            FieldInnerTy::Option(ty) | FieldInnerTy::Vec(ty) | FieldInnerTy::Plain(ty) => ty.span(),
+        }
+    }
 }
 
 /// Field information passed to the builder. Deliberately omits attrs to discourage the

tests/ui-fulldeps/session-diagnostic/diagnostic-derive-doc-comment-field.rs

@@ -27,21 +27,21 @@ fluent_messages! { "./example.ftl" }
 struct NotIntoDiagnosticArg;
 
 #[derive(Diagnostic)]
-//~^ ERROR the trait bound `NotIntoDiagnosticArg: IntoDiagnosticArg` is not satisfied
 #[diag(no_crate_example)]
 struct Test {
     #[primary_span]
     span: Span,
     /// A doc comment
     arg: NotIntoDiagnosticArg,
+    //~^ ERROR the trait bound `NotIntoDiagnosticArg: IntoDiagnosticArg` is not satisfied
 }
 
 #[derive(Subdiagnostic)]
-//~^ ERROR the trait bound `NotIntoDiagnosticArg: IntoDiagnosticArg` is not satisfied
 #[label(no_crate_example)]
 struct SubTest {
     #[primary_span]
     span: Span,
     /// A doc comment
     arg: NotIntoDiagnosticArg,
+    //~^ ERROR the trait bound `NotIntoDiagnosticArg: IntoDiagnosticArg` is not satisfied
 }

tests/ui-fulldeps/session-diagnostic/diagnostic-derive-doc-comment-field.stderr

@@ -1,8 +1,11 @@
 error[E0277]: the trait bound `NotIntoDiagnosticArg: IntoDiagnosticArg` is not satisfied
-  --> $DIR/diagnostic-derive-doc-comment-field.rs:29:10
+  --> $DIR/diagnostic-derive-doc-comment-field.rs:35:10
    |
 LL | #[derive(Diagnostic)]
-   |          ^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `NotIntoDiagnosticArg`
+   |          ---------- required by a bound introduced by this call
+...
+LL |     arg: NotIntoDiagnosticArg,
+   |          ^^^^^^^^^^^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `NotIntoDiagnosticArg`
    |
    = help: the following other types implement trait `IntoDiagnosticArg`:
              &'a T
@@ -16,13 +19,16 @@ LL | #[derive(Diagnostic)]
            and 42 others
 note: required by a bound in `DiagnosticBuilder::<'a, G>::set_arg`
   --> $COMPILER_DIR/rustc_errors/src/diagnostic_builder.rs:747:5
-   = note: this error originates in the derive macro `Diagnostic` which comes from the expansion of the macro `forward` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `forward` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `NotIntoDiagnosticArg: IntoDiagnosticArg` is not satisfied
-  --> $DIR/diagnostic-derive-doc-comment-field.rs:39:10
+  --> $DIR/diagnostic-derive-doc-comment-field.rs:45:10
    |
 LL | #[derive(Subdiagnostic)]
-   |          ^^^^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `NotIntoDiagnosticArg`
+   |          ------------- required by a bound introduced by this call
+...
+LL |     arg: NotIntoDiagnosticArg,
+   |          ^^^^^^^^^^^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `NotIntoDiagnosticArg`
    |
    = help: the following other types implement trait `IntoDiagnosticArg`:
              &'a T
@@ -36,7 +42,6 @@ LL | #[derive(Subdiagnostic)]
            and 42 others
 note: required by a bound in `Diagnostic::set_arg`
   --> $COMPILER_DIR/rustc_errors/src/diagnostic.rs:964:5
-   = note: this error originates in the derive macro `Subdiagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 2 previous errors
 

tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs

@@ -339,12 +339,12 @@ struct ErrorWithDefaultLabelAttr<'a> {
 }
 
 #[derive(Diagnostic)]
-//~^ ERROR the trait bound `Hello: IntoDiagnosticArg` is not satisfied
 #[diag(no_crate_example, code = "E0123")]
 struct ArgFieldWithoutSkip {
     #[primary_span]
     span: Span,
     other: Hello,
+    //~^ ERROR the trait bound `Hello: IntoDiagnosticArg` is not satisfied
 }
 
 #[derive(Diagnostic)]

tests/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr

@@ -641,15 +641,18 @@ LL | #[derive(Diagnostic)]
    = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `Hello: IntoDiagnosticArg` is not satisfied
-  --> $DIR/diagnostic-derive.rs:341:10
+  --> $DIR/diagnostic-derive.rs:346:12
    |
 LL | #[derive(Diagnostic)]
-   |          ^^^^^^^^^^ the trait `IntoDiagnosticArg` is not implemented for `Hello`
+   |          ---------- required by a bound introduced by this call
+...
+LL |     other: Hello,
+   |            ^^^^^ the trait `IntoDiagnosticArg` is not implemented for `Hello`
    |
    = help: normalized in stderr
 note: required by a bound in `DiagnosticBuilder::<'a, G>::set_arg`
   --> $COMPILER_DIR/rustc_errors/src/diagnostic_builder.rs:LL:CC
-   = note: this error originates in the derive macro `Diagnostic` which comes from the expansion of the macro `forward` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the macro `forward` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 84 previous errors