Remove duplicated code

src/librustc/traits/error_reporting/mod.rs

@@ -27,7 +27,6 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
-use rustc_span::source_map::SourceMap;
 use rustc_span::{ExpnKind, Span, DUMMY_SP};
 use std::fmt;
 use syntax::ast;
@@ -1427,74 +1426,3 @@ impl ArgKind {
         }
     }
 }
-
-/// Suggest restricting a type param with a new bound.
-pub fn suggest_constraining_type_param(
-    generics: &hir::Generics<'_>,
-    err: &mut DiagnosticBuilder<'_>,
-    param_name: &str,
-    constraint: &str,
-    source_map: &SourceMap,
-    span: Span,
-) -> bool {
-    let restrict_msg = "consider further restricting this bound";
-    if let Some(param) =
-        generics.params.iter().filter(|p| p.name.ident().as_str() == param_name).next()
-    {
-        if param_name.starts_with("impl ") {
-            // `impl Trait` in argument:
-            // `fn foo(x: impl Trait) {}` → `fn foo(t: impl Trait + Trait2) {}`
-            err.span_suggestion(
-                param.span,
-                restrict_msg,
-                // `impl CurrentTrait + MissingTrait`
-                format!("{} + {}", param_name, constraint),
-                Applicability::MachineApplicable,
-            );
-        } else if generics.where_clause.predicates.is_empty() && param.bounds.is_empty() {
-            // If there are no bounds whatsoever, suggest adding a constraint
-            // to the type parameter:
-            // `fn foo<T>(t: T) {}` → `fn foo<T: Trait>(t: T) {}`
-            err.span_suggestion(
-                param.span,
-                "consider restricting this bound",
-                format!("{}: {}", param_name, constraint),
-                Applicability::MachineApplicable,
-            );
-        } else if !generics.where_clause.predicates.is_empty() {
-            // There is a `where` clause, so suggest expanding it:
-            // `fn foo<T>(t: T) where T: Debug {}` →
-            // `fn foo<T>(t: T) where T: Debug, T: Trait {}`
-            err.span_suggestion(
-                generics.where_clause.span().unwrap().shrink_to_hi(),
-                &format!("consider further restricting type parameter `{}`", param_name),
-                format!(", {}: {}", param_name, constraint),
-                Applicability::MachineApplicable,
-            );
-        } else {
-            // If there is no `where` clause lean towards constraining to the
-            // type parameter:
-            // `fn foo<X: Bar, T>(t: T, x: X) {}` → `fn foo<T: Trait>(t: T) {}`
-            // `fn foo<T: Bar>(t: T) {}` → `fn foo<T: Bar + Trait>(t: T) {}`
-            let sp = param.span.with_hi(span.hi());
-            let span = source_map.span_through_char(sp, ':');
-            if sp != param.span && sp != span {
-                // Only suggest if we have high certainty that the span
-                // covers the colon in `foo<T: Trait>`.
-                err.span_suggestion(
-                    span,
-                    restrict_msg,
-                    format!("{}: {} + ", param_name, constraint),
-                    Applicability::MachineApplicable,
-                );
-            } else {
-                err.span_label(
-                    param.span,
-                    &format!("consider adding a `where {}: {}` bound", param_name, constraint),
-                );
-            }
-        }
-        return true;
-    }
-    false
-}

src/librustc_mir/borrow_check/diagnostics/conflict_errors.rs

@@ -3,7 +3,7 @@ use rustc::mir::{
     FakeReadCause, Local, LocalDecl, LocalInfo, LocalKind, Location, Operand, Place, PlaceRef,
     ProjectionElem, Rvalue, Statement, StatementKind, TerminatorKind, VarBindingForm,
 };
-use rustc::traits::error_reporting::suggest_constraining_type_param;
+use rustc::traits::error_reporting::suggestions::suggest_constraining_type_param;
 use rustc::ty::{self, Ty};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, DiagnosticBuilder};