1 files changed, 41 insertions, 20 deletions

diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index d9776be4dd0..5f0a2a597e9 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -1117,13 +1117,14 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         debug!("validate_res_from_ribs({:?})", res);
         let ribs = &all_ribs[rib_index + 1..];
 
-        // An invalid forward use of a generic parameter from a previous default.
-        if let RibKind::ForwardGenericParamBan = all_ribs[rib_index].kind {
+        // An invalid forward use of a generic parameter from a previous default
+        // or in a const param ty.
+        if let RibKind::ForwardGenericParamBan(reason) = all_ribs[rib_index].kind {
             if let Some(span) = finalize {
                 let res_error = if rib_ident.name == kw::SelfUpper {
-                    ResolutionError::SelfInGenericParamDefault
+                    ResolutionError::ForwardDeclaredSelf(reason)
                 } else {
-                    ResolutionError::ForwardDeclaredGenericParam
+                    ResolutionError::ForwardDeclaredGenericParam(rib_ident.name, reason)
                 };
                 self.report_error(span, res_error);
             }
@@ -1131,17 +1132,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             return Res::Err;
         }
 
-        if let RibKind::ConstParamTy = all_ribs[rib_index].kind {
-            if let Some(span) = finalize {
-                self.report_error(
-                    span,
-                    ResolutionError::ParamInTyOfConstParam { name: rib_ident.name },
-                );
-            }
-            assert_eq!(res, Res::Err);
-            return Res::Err;
-        }
-
         match res {
             Res::Local(_) => {
                 use ResolutionError::*;
@@ -1153,7 +1143,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         | RibKind::FnOrCoroutine
                         | RibKind::Module(..)
                         | RibKind::MacroDefinition(..)
-                        | RibKind::ForwardGenericParamBan => {
+                        | RibKind::ForwardGenericParamBan(_) => {
                             // Nothing to do. Continue.
                         }
                         RibKind::Item(..) | RibKind::AssocItem => {
@@ -1247,12 +1237,27 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         | RibKind::MacroDefinition(..)
                         | RibKind::InlineAsmSym
                         | RibKind::AssocItem
-                        | RibKind::ConstParamTy
-                        | RibKind::ForwardGenericParamBan => {
+                        | RibKind::ForwardGenericParamBan(_) => {
                             // Nothing to do. Continue.
                             continue;
                         }
 
+                        RibKind::ConstParamTy => {
+                            if !self.tcx.features().generic_const_parameter_types() {
+                                if let Some(span) = finalize {
+                                    self.report_error(
+                                        span,
+                                        ResolutionError::ParamInTyOfConstParam {
+                                            name: rib_ident.name,
+                                        },
+                                    );
+                                }
+                                return Res::Err;
+                            } else {
+                                continue;
+                            }
+                        }
+
                         RibKind::ConstantItem(trivial, _) => {
                             if let ConstantHasGenerics::No(cause) = trivial {
                                 // HACK(min_const_generics): If we encounter `Self` in an anonymous
@@ -1325,8 +1330,23 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         | RibKind::MacroDefinition(..)
                         | RibKind::InlineAsmSym
                         | RibKind::AssocItem
-                        | RibKind::ConstParamTy
-                        | RibKind::ForwardGenericParamBan => continue,
+                        | RibKind::ForwardGenericParamBan(_) => continue,
+
+                        RibKind::ConstParamTy => {
+                            if !self.tcx.features().generic_const_parameter_types() {
+                                if let Some(span) = finalize {
+                                    self.report_error(
+                                        span,
+                                        ResolutionError::ParamInTyOfConstParam {
+                                            name: rib_ident.name,
+                                        },
+                                    );
+                                }
+                                return Res::Err;
+                            } else {
+                                continue;
+                            }
+                        }
 
                         RibKind::ConstantItem(trivial, _) => {
                             if let ConstantHasGenerics::No(cause) = trivial {
@@ -1377,6 +1397,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             }
             _ => {}
         }
+
         res
     }