changing diagnostics err to use ValueDecl and created note

Author: dancamarotto

include/swift/AST/DiagnosticsSema.def

@@ -1055,7 +1055,9 @@ NOTE(single_confusable_character,none,
 ERROR(cannot_find_type_in_scope,none,
       "cannot find type %0 in scope", (DeclNameRef))
 ERROR(cannot_find_type_in_cast_expression,none,
-      "type-casting operator expects a type on its right-hand side (got: %0)", (DeclNameRef))
+      "type-casting operator expects a type on its right-hand side (got: %0)", (const ValueDecl *))
+NOTE(note_declared_here,none,
+      "declared here",())
 ERROR(cannot_find_type_in_scope_did_you_mean,none,
       "cannot find type %0 in scope; did you mean to use '%1'?", (DeclNameRef, StringRef))
 NOTE(note_typo_candidate_implicit_member,none,

lib/Sema/TypeCheckType.cpp

@@ -1388,8 +1388,10 @@ static Type diagnoseUnknownType(TypeResolution resolution,
       auto lookupResult = TypeChecker::lookupUnqualified(
           dc, repr->getNameRef(), repr->getLoc(), lookupOptions);
       if (!lookupResult.empty()) {
-        diags.diagnose(L, diag::cannot_find_type_in_cast_expression, repr->getNameRef())
+        auto first = lookupResult.front().getValueDecl();
+        diags.diagnose(L, diag::cannot_find_type_in_cast_expression, first)
           .highlight(R);
+        diags.diagnose(first->getNameLoc(), diag::note_declared_here);
         return ErrorType::get(ctx);
       }
     }

test/Constraints/casts.swift

@@ -745,8 +745,13 @@ do {
 // https://github.com/apple/swift/issues/68825
 do {
   func x(a: Any) {
-    _ = a is a // expected-error {{type-casting operator expects a type on its right-hand side (got: 'a')}}
-    _ = a as a // expected-error {{type-casting operator expects a type on its right-hand side (got: 'a')}}
+    _ = a is a
+    // expected-error@-1 {{type-casting operator expects a type on its right-hand side (got: 'a')}}
+    // expected-note@-3 {{declared here}}
+    _ = a as a
+    // expected-error@-1 {{type-casting operator expects a type on its right-hand side (got: 'a')}}
+    // expected-note@-6 {{declared here}}
+    _ = a is Issue68825 // expected-error {{cannot find type 'Issue68825' in scope}}
     _ = a is String // OK
   }
 }

test/Parse/omit_return.swift

@@ -1711,6 +1711,7 @@ class CImplicitDotSelfExpr { func gimme() -> CImplicitDotSelfExpr { self.self }
 
 func badIs<T>(_ value: Any, anInstanceOf type: T.Type) -> Bool {
     value is type // expected-error {{type-casting operator expects a type on its right-hand side (got: 'type')}}
+    // expected-note@-2 {{declared here}}
 }
 
 

test/Parse/omit_return_fail.swift

@@ -2,6 +2,7 @@
 
 func badIs<T>(_ value: Any, anInstanceOf type: T.Type) -> Bool {
     value is type // expected-error {{type-casting operator expects a type on its right-hand side (got: 'type')}}
+    // expected-note@-2 {{declared here}}
 }
 
 func foo() -> Int {
@@ -11,6 +12,7 @@ func foo() -> Int {
 func badIs_ifdecl<T>(_ value: Any, anInstanceOf type: T.Type) -> Bool {
     #if true
     value is type // expected-error {{type-casting operator expects a type on its right-hand side (got: 'type')}}
+    // expected-note@-3 {{declared here}}
     #endif
 }
 

test/Parse/omit_return_ifdecl.swift

@@ -2433,6 +2433,7 @@ class CImplicitDotSelfExpr { func gimme() -> CImplicitDotSelfExpr { self.self }
 func badIs<T>(_ value: Any, anInstanceOf type: T.Type) -> Bool {
     #if true
     value is type // expected-error {{type-casting operator expects a type on its right-hand side (got: 'type')}}
+    // expected-note@-3 {{declared here}}
     #endif
 }