Rollup merge of rust-lang#97471 - estebank:prohibit-generics, r=cjgillot

Provide more context when denying invalid type params

Author: Dylan-DPC

compiler/rustc_typeck/src/astconv/mod.rs

@@ -1228,6 +1228,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     None
                 }
             }),
+            |_| {},
         );
 
         if let Res::Local(hid) = res {

compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs

@@ -1564,13 +1564,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             QPath::TypeRelative(ref qself, ref segment) => {
                 let ty = self.to_ty(qself);
 
-                let res = if let hir::TyKind::Path(QPath::Resolved(_, ref path)) = qself.kind {
-                    path.res
-                } else {
-                    Res::Err
-                };
                 let result = <dyn AstConv<'_>>::associated_path_to_ty(
-                    self, hir_id, path_span, ty, res, segment, true,
+                    self, hir_id, path_span, ty, qself, segment, true,
                 );
                 let ty = result.map(|(ty, _, _)| ty).unwrap_or_else(|_| self.tcx().ty_error());
                 let result = result.map(|(_, kind, def_id)| (kind, def_id));

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -1,7 +1,7 @@
 use std::fmt::Debug;
 
 #[derive(Debug)]
-pub struct Irrelevant<Irrelevant> { //~ ERROR type arguments are not allowed for this type
+pub struct Irrelevant<Irrelevant> { //~ ERROR type arguments are not allowed on type parameter
     irrelevant: Irrelevant,
 }
 

src/test/ui/derives/issue-97343.rs

@@ -1,11 +1,19 @@
-error[E0109]: type arguments are not allowed for this type
+error[E0109]: type arguments are not allowed on type parameter `Irrelevant`
   --> $DIR/issue-97343.rs:4:23
    |
 LL | #[derive(Debug)]
-   |          ----- in this derive macro expansion
+   |          -----
+   |          |
+   |          not allowed on this
+   |          in this derive macro expansion
 LL | pub struct Irrelevant<Irrelevant> {
    |                       ^^^^^^^^^^ type argument not allowed
    |
+note: type parameter `Irrelevant` defined here
+  --> $DIR/issue-97343.rs:4:23
+   |
+LL | pub struct Irrelevant<Irrelevant> {
+   |                       ^^^^^^^^^^
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/derives/issue-97343.stderr

@@ -1,8 +1,16 @@
-error[E0109]: type arguments are not allowed for this type
+error[E0109]: type arguments are not allowed on this type
   --> $DIR/E0109.rs:1:14
    |
 LL | type X = u32<i32>;
-   |              ^^^ type argument not allowed
+   |          --- ^^^ type argument not allowed
+   |          |
+   |          not allowed on this
+   |
+help: primitive type `u32` doesn't have generic parameters
+   |
+LL - type X = u32<i32>;
+LL + type X = u32;
+   | 
 
 error: aborting due to previous error
 

src/test/ui/error-codes/E0109.stderr

@@ -1,8 +1,16 @@
-error[E0109]: lifetime arguments are not allowed for this type
+error[E0109]: lifetime arguments are not allowed on this type
   --> $DIR/E0110.rs:1:14
    |
 LL | type X = u32<'static>;
-   |              ^^^^^^^ lifetime argument not allowed
+   |          --- ^^^^^^^ lifetime argument not allowed
+   |          |
+   |          not allowed on this
+   |
+help: primitive type `u32` doesn't have generic parameters
+   |
+LL - type X = u32<'static>;
+LL + type X = u32;
+   | 
 
 error: aborting due to previous error
 

src/test/ui/error-codes/E0110.stderr

@@ -1,3 +1,3 @@
 fn is_copy<T: ::std::marker<i32>::Copy>() {}
-//~^ ERROR type arguments are not allowed for this type [E0109]
+//~^ ERROR type arguments are not allowed on module `marker` [E0109]
 fn main() {}

src/test/ui/issues/issue-22706.rs

@@ -1,8 +1,10 @@
-error[E0109]: type arguments are not allowed for this type
+error[E0109]: type arguments are not allowed on module `marker`
   --> $DIR/issue-22706.rs:1:29
    |
 LL | fn is_copy<T: ::std::marker<i32>::Copy>() {}
-   |                             ^^^ type argument not allowed
+   |                      ------ ^^^ type argument not allowed
+   |                      |
+   |                      not allowed on this
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-22706.stderr

@@ -3,7 +3,7 @@ pub struct Gcm<E>(E);
 impl<E> Gcm<E> {
     pub fn crash(e: E) -> Self {
         Self::<E>(e)
-        //~^ ERROR type arguments are not allowed for this type
+        //~^ ERROR type arguments are not allowed on self constructor
     }
 }