[CSFix] Allow diagnosing the same out-of-order argument in ambiguity cases

Is the same argument is out-of-order in multiple solutions, let's
diagnose it as if there was no ambiguity.

Resolves: SR-14093
Resolves: rdar://73600328

Author: xedin

include/swift/Sema/CSFix.h

@@ -1394,11 +1394,19 @@ class MoveOutOfOrderArgument final : public ConstraintFix {
 
   bool diagnose(const Solution &solution, bool asNote = false) const override;
 
+  bool diagnoseForAmbiguity(CommonFixesArray commonFixes) const override;
+
+  bool isEqual(const ConstraintFix *other) const;
+
   static MoveOutOfOrderArgument *create(ConstraintSystem &cs,
                                         unsigned argIdx,
                                         unsigned prevArgIdx,
                                         ArrayRef<ParamBinding> bindings,
                                         ConstraintLocator *locator);
+
+  static bool classof(const ConstraintFix *fix) {
+    return fix->getKind() == FixKind::MoveOutOfOrderArgument;
+  }
 };
 
 class AllowInaccessibleMember final : public AllowInvalidMemberRef {

lib/Sema/CSFix.cpp

@@ -865,6 +865,29 @@ bool MoveOutOfOrderArgument::diagnose(const Solution &solution,
   return failure.diagnose(asNote);
 }
 
+bool MoveOutOfOrderArgument::diagnoseForAmbiguity(
+    CommonFixesArray commonFixes) const {
+  auto *primaryFix =
+      commonFixes.front().second->getAs<MoveOutOfOrderArgument>();
+  assert(primaryFix);
+
+  if (llvm::all_of(
+          commonFixes,
+          [&primaryFix](
+              const std::pair<const Solution *, const ConstraintFix *> &entry) {
+            return primaryFix->isEqual(entry.second);
+          }))
+    return diagnose(*commonFixes.front().first);
+
+  return false;
+}
+
+bool MoveOutOfOrderArgument::isEqual(const ConstraintFix *other) const {
+  auto OoOFix = other->getAs<MoveOutOfOrderArgument>();
+  return OoOFix ? ArgIdx == OoOFix->ArgIdx && PrevArgIdx == OoOFix->PrevArgIdx
+                : false;
+}
+
 MoveOutOfOrderArgument *MoveOutOfOrderArgument::create(
     ConstraintSystem &cs, unsigned argIdx, unsigned prevArgIdx,
     ArrayRef<ParamBinding> bindings, ConstraintLocator *locator) {

validation-test/Sema/SwiftUI/sr14093.swift

@@ -0,0 +1,20 @@
+// RUN: %target-typecheck-verify-swift -target x86_64-apple-macosx10.15 -swift-version 5
+
+// REQUIRES: objc_interop
+// REQUIRES: OS=macosx
+
+import SwiftUI
+import Foundation
+
+struct ContentView: View {
+  @State private var date = Date()
+
+  var body: some View {
+    Group {
+      DatePicker("Enter a date", selection: $date, displayedComponents: .date, in: Date())
+      // expected-error@-1 {{argument 'in' must precede argument 'displayedComponents'}} {{78-90=}} {{52-52=in: Date(), }}
+      DatePicker("Enter a date", selection: $date, displayedComponents: .date, in: Date() ... Date().addingTimeInterval(100))
+      // expected-error@-1 {{argument 'in' must precede argument 'displayedComponents'}} {{78-125=}} {{52-52=in: Date() ... Date().addingTimeInterval(100), }}
+    }
+  }
+}