Merge pull request #63838 from xedin/extra-force-unwrap-in-ambiguous-context

[CSFix] Diagnose extraneous force unwraps in ambiguous context

Author: xedin

include/swift/Sema/CSFix.h

@@ -1205,6 +1205,10 @@ class RemoveUnwrap final : public ConstraintFix {
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
 
+  bool diagnoseForAmbiguity(CommonFixesArray commonFixes) const override {
+    return diagnose(*commonFixes.front().first);
+  }
+
   static RemoveUnwrap *create(ConstraintSystem &cs, Type baseType,
                               ConstraintLocator *locator);
 

test/Constraints/optional.swift

@@ -588,4 +588,14 @@ do {
     takesP(value)
     // expected-error@-1 {{argument type '(any BinaryInteger)?' does not conform to expected type 'P'}}
   }
-}
+}
+
+// Diagnose extraneous force unwrap in ambiguous context
+do {
+  func test(_: Int) {} // expected-note {{found this candidate}}
+  func test(_: String) {} // expected-note {{found this candidate}}
+
+  var x: Double = 42
+  test(x!) // expected-error {{no exact matches in call to local function 'test'}}
+  // expected-error@-1 {{cannot force unwrap value of non-optional type 'Double'}}
+}

test/StringProcessing/Parse/forward-slash-regex.swift

@@ -121,6 +121,7 @@ do {
 } // expected-error {{expected expression after operator}}
 
 _ = /x/??/x/ // expected-error {{'/' is not a postfix unary operator}}
+// expected-error@-1 2 {{cannot use optional chaining on non-optional value of type 'Regex<Substring>'}}
 
 _ = /x/ ... /y/ // expected-error {{referencing operator function '...' on 'Comparable' requires that 'Regex<Substring>' conform to 'Comparable'}}