Merge pull request #30510 from HassanElDesouky/SR-12309-FollowUp

[CSGen] Diagnose `nil` with any number of parentheses

Author: xedin

lib/Sema/CSGen.cpp

@@ -1152,7 +1152,7 @@ namespace {
       // `_ = nil`, let's diagnose it here because solver can't
       // attempt any types for it.
       auto *parentExpr = CS.getParentExpr(expr);
-      if (parentExpr && isa<ParenExpr>(parentExpr))
+      while (parentExpr && isa<ParenExpr>(parentExpr))
         parentExpr = CS.getParentExpr(parentExpr);
 
       if (parentExpr) {

test/Constraints/optional.swift

@@ -436,9 +436,16 @@ func sr_12309() {
 
   _ = S(foo: nil!) // expected-error {{'nil' literal cannot be force unwrapped}}
   _ = nil! // expected-error {{'nil' literal cannot be force unwrapped}}
+  _ = (nil!) // expected-error {{'nil' literal cannot be force unwrapped}}
+  _ = (nil)! // expected-error {{'nil' literal cannot be force unwrapped}}
+  _ = ((nil))! // expected-error {{'nil' literal cannot be force unwrapped}}
   _ = nil? // expected-error {{value of optional type 'Optional<_>' must be unwrapped to a value of type '_'}}
            // expected-note@-1 {{coalesce using '??' to provide a default when the optional value contains 'nil'}}
            // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}}
-  _ = (nil) // expected-error {{'nil' requires a contextual type}}
   _ = nil // expected-error {{'nil' requires a contextual type}}
+  _ = (nil) // expected-error {{'nil' requires a contextual type}}
+  _ = ((nil)) // expected-error {{'nil' requires a contextual type}}
+  _ = (((nil))) // expected-error {{'nil' requires a contextual type}}
+  _ = ((((((nil)))))) // expected-error {{'nil' requires a contextual type}}
+  _ = (((((((((nil))))))))) // expected-error {{'nil' requires a contextual type}}
 }