diff options
Diffstat (limited to 'compiler/rustc_monomorphize/src/polymorphize.rs')
| -rw-r--r-- | compiler/rustc_monomorphize/src/polymorphize.rs | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/compiler/rustc_monomorphize/src/polymorphize.rs b/compiler/rustc_monomorphize/src/polymorphize.rs index 394843e510d..88f8e24fbd5 100644 --- a/compiler/rustc_monomorphize/src/polymorphize.rs +++ b/compiler/rustc_monomorphize/src/polymorphize.rs @@ -22,6 +22,8 @@ use rustc_span::symbol::sym; use std::convert::TryInto; use std::ops::ControlFlow; +use crate::errors::UnusedGenericParams; + /// Provide implementations of queries relating to polymorphization analysis. pub fn provide(providers: &mut Providers) { providers.unused_generic_params = unused_generic_params; @@ -206,22 +208,28 @@ fn emit_unused_generic_params_error<'tcx>( _ => tcx.def_span(def_id), }; - let mut err = tcx.sess.struct_span_err(fn_span, "item has unused generic parameters"); - + let mut param_spans = Vec::new(); + let mut param_names = Vec::new(); let mut next_generics = Some(generics); while let Some(generics) = next_generics { for param in &generics.params { if unused_parameters.contains(param.index).unwrap_or(false) { debug!(?param); let def_span = tcx.def_span(param.def_id); - err.span_label(def_span, &format!("generic parameter `{}` is unused", param.name)); + // 🤔 The docs say + // + // Any attribute applied to a Vec<T> will be repeated for each element of the vector. + // + // But they don't say what template variable to use to substitute each value into the message!? + param_spans.push(def_span); + param_names.push(param.name.to_string()); } } next_generics = generics.parent.map(|did| tcx.generics_of(did)); } - err.emit(); + tcx.sess.emit_err(UnusedGenericParams { span: fn_span, param_spans, param_names }); } /// Visitor used to aggregate generic parameter uses. |