Add a fixit for attempting member lookup on Any.

Suggest casting to AnyObject or a more specific type.

rdar://problem/27639935

Author: rudkx

include/swift/AST/DiagnosticsSema.def

@@ -75,6 +75,9 @@ ERROR(could_not_find_type_member,none,
 NOTE(did_you_mean_raw_type,none,
      "did you mean to specify a raw type on the enum declaration?", ())
 
+NOTE(any_as_anyobject_fixit, none,
+     "cast 'Any' to 'AnyObject' or use 'as!' to force downcast to a more specific type to access members", ())
+
 ERROR(expected_argument_in_contextual_member,none,
       "contextual member %0 expects argument of type %1", (DeclName, Type))
 

lib/Sema/CSDiag.cpp

@@ -2490,6 +2490,14 @@ diagnoseUnviableLookupResults(MemberLookupResult &result, Type baseObjTy,
           diagnose(loc, diag::did_you_mean_raw_type);
           return; // Always prefer this over typo corrections.
         }
+      } else if (baseObjTy->isAny()) {
+        if (auto DRE = dyn_cast<DeclRefExpr>(baseExpr)) {
+          auto name = DRE->getDecl()->getName().str().str();
+          std::string replacement = "(" + name + " as AnyObject)";
+          diagnose(loc, diag::any_as_anyobject_fixit)
+            .fixItReplace(baseExpr->getSourceRange(), replacement);
+          return;
+        }
       }
     }
 

test/Constraints/dynamic_lookup.swift

@@ -219,3 +219,9 @@ uopt.wibble!()
 // Should not be able to see private or internal @objc methods.
 uopt.privateFoo!() // expected-error{{'privateFoo' is inaccessible due to 'private' protection level}}
 uopt.internalFoo!() // expected-error{{'internalFoo' is inaccessible due to 'internal' protection level}}
+
+let anyValue: Any = X()
+_ = anyValue.bar() // expected-error {{value of type 'Any' has no member 'bar'}}
+// expected-note@-1 {{cast 'Any' to 'AnyObject' or use 'as!' to force downcast to a more specific type to access members}}{{5-13=(anyValue as AnyObject)}}
+_ = (anyValue as AnyObject).bar()
+_ = (anyValue as! X).bar()

test/Constraints/tuple.swift

@@ -61,6 +61,9 @@ any = (label: 4)
 // Scalars don't have .0/.1/etc
 i = j.0 // expected-error{{value of type 'Int' has no member '0'}}
 any.1 // expected-error{{value of type 'Any' has no member '1'}}
+// expected-note@-1{{cast 'Any' to 'AnyObject' or use 'as!' to force downcast to a more specific type to access members}}
+any = (5.0, 6.0) as (Float, Float)
+_ = (any as! (Float, Float)).1
 
 // Fun with tuples
 protocol PosixErrorReturn {