From fe8fd913071b63d80754b906b92d6fa887529a4a Mon Sep 17 00:00:00 2001
From: Pavel Yaskevich <pyaskevich@apple.com>
Date: Thu, 25 May 2023 14:35:43 -0700
Subject: [PATCH] [AST] NFC: Fold `PackConformance::isInvalid` into
 `ProtocolConformanceRef::isInvalid`

Instead of making callers responsible for that (like in other cases),
let's fold the code check `isInvalid` to make mistakes less likely.
---
 include/swift/AST/ProtocolConformanceRef.h |  4 +---
 lib/AST/Module.cpp                         |  7 ++-----
 lib/AST/PackConformance.cpp                |  3 ---
 lib/AST/ProtocolConformanceRef.cpp         | 10 ++++++++++
 4 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/include/swift/AST/ProtocolConformanceRef.h b/include/swift/AST/ProtocolConformanceRef.h
index 4f1fa2e244bc4..5a9a02dc5b668 100644
--- a/include/swift/AST/ProtocolConformanceRef.h
+++ b/include/swift/AST/ProtocolConformanceRef.h
@@ -89,9 +89,7 @@ class ProtocolConformanceRef {
   static ProtocolConformanceRef forMissingOrInvalid(
       Type type, ProtocolDecl *proto);
 
-  bool isInvalid() const {
-    return !Union;
-  }
+  bool isInvalid() const;
 
   explicit operator bool() const { return !isInvalid(); }
 
diff --git a/lib/AST/Module.cpp b/lib/AST/Module.cpp
index 48bc77b642355..6623179e0f718 100644
--- a/lib/AST/Module.cpp
+++ b/lib/AST/Module.cpp
@@ -1827,11 +1827,8 @@ static ProtocolConformanceRef getPackTypeConformance(
     patternConformances.push_back(patternConformance);
   }
 
-  auto *conformance = PackConformance::get(type, protocol, patternConformances);
-  if (conformance->isInvalid())
-    return ProtocolConformanceRef::forInvalid();
-
-  return ProtocolConformanceRef(conformance);
+  return ProtocolConformanceRef(
+      PackConformance::get(type, protocol, patternConformances));
 }
 
 ProtocolConformanceRef
diff --git a/lib/AST/PackConformance.cpp b/lib/AST/PackConformance.cpp
index b1cc1f19f2ddd..1a4270f65a028 100644
--- a/lib/AST/PackConformance.cpp
+++ b/lib/AST/PackConformance.cpp
@@ -249,9 +249,6 @@ PackConformance::subst(InFlightSubstitution &IFS) const {
 
   auto substConformance = PackConformance::get(substConformingType, Protocol,
                                                expander.substConformances);
-  if (substConformance->isInvalid())
-    return ProtocolConformanceRef::forInvalid();
-
   return ProtocolConformanceRef(substConformance);
 }
 
diff --git a/lib/AST/ProtocolConformanceRef.cpp b/lib/AST/ProtocolConformanceRef.cpp
index ccde9d8d81f45..c01b15b48c7c4 100644
--- a/lib/AST/ProtocolConformanceRef.cpp
+++ b/lib/AST/ProtocolConformanceRef.cpp
@@ -42,6 +42,16 @@ ProtocolConformanceRef::ProtocolConformanceRef(ProtocolDecl *protocol,
   }
 }
 
+bool ProtocolConformanceRef::isInvalid() const {
+  if (!Union)
+    return true;
+
+  if (auto pack = Union.dyn_cast<PackConformance *>())
+    return pack->isInvalid();
+
+  return false;
+}
+
 ProtocolDecl *ProtocolConformanceRef::getRequirement() const {
   assert(!isInvalid());