Merge pull request #64734 from tristanlabelle/fix-available-attribute-out-of-bounds-access

Fix out-of-bounds when providing fixits for the @available attribute.

Author: xedin

lib/Sema/TypeCheckAvailability.cpp

@@ -2508,11 +2508,11 @@ static void fixItAvailableAttrRename(InFlightDiagnostic &diag,
   auto I = argumentLabelIDs.begin();
 
   auto updateLabelsForArg = [&](Expr *expr) -> bool {
+    if (I == argumentLabelIDs.end())
+      return true;
+
     if (isa<DefaultArgumentExpr>(expr)) {
       // Defaulted: remove param label of it.
-      if (I == argumentLabelIDs.end())
-        return true;
-
       I = argumentLabelIDs.erase(I);
       return false;
     }
@@ -2539,9 +2539,6 @@ static void fixItAvailableAttrRename(InFlightDiagnostic &diag,
     }
 
     // Normal: Just advance.
-    if (I == argumentLabelIDs.end())
-      return true;
-
     ++I;
     return false;
   };

test/attr/attr_availability_unavailability.swift

@@ -58,4 +58,14 @@ func testUnavailableExpandAllElsePaths() {
   } else {
     foo()
   }
-} 
+}
+
+func log(message: String) {}
+
+@available(*, unavailable, renamed: "log(message:)")
+func log(format: String, _ args: Any...) { fatalError() } // expected-note {{'log(format:_:)' has been explicitly marked unavailable here}}
+
+// Regression test for https://github.com/apple/swift/issues/64694
+func testUnavailableRenamedFromVariadicDoesntAssert() {
+  log(format: "") // expected-error{{'log(format:_:)' has been renamed to 'log(message:)'}}
+}