From f4ac79a364f2de7270a3238b176e17b40b036305 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Tue, 8 Sep 2020 20:06:07 +0000
Subject: [PATCH] Sema: extract a check for `isCFError` (NFC)

Extract a simple check to check if a `RecordDecl` is a `CFError` Decl.
This is a simple refactoring to prepare for an upcoming change.  NFC.

Patch is extracted from
https://github.com/llvm/llvm-project-staging/commit/8afaf3aad2af43cfedca7a24cd817848c4e95c0c.
---
 clang/include/clang/Sema/Sema.h |  1 +
 clang/lib/Sema/SemaType.cpp     | 52 +++++++++++++++++----------------
 2 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 53d0285d3702..129ac0355c87 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -12415,6 +12415,7 @@ public:
 
   /// The struct behind the CFErrorRef pointer.
   RecordDecl *CFError = nullptr;
+  bool isCFError(RecordDecl *D);
 
   /// Retrieve the identifier "NSError".
   IdentifierInfo *getNSErrorIdent();
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 03442fb03b3a..d8ea9c037259 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4043,32 +4043,9 @@ classifyPointerDeclarator(Sema &S, QualType type, Declarator &declarator,
     if (auto recordType = type->getAs<RecordType>()) {
       RecordDecl *recordDecl = recordType->getDecl();
 
-      bool isCFError = false;
-      if (S.CFError) {
-        // If we already know about CFError, test it directly.
-        isCFError = (S.CFError == recordDecl);
-      } else {
-        // Check whether this is CFError, which we identify based on its bridge
-        // to NSError. CFErrorRef used to be declared with "objc_bridge" but is
-        // now declared with "objc_bridge_mutable", so look for either one of
-        // the two attributes.
-        if (recordDecl->getTagKind() == TTK_Struct && numNormalPointers > 0) {
-          IdentifierInfo *bridgedType = nullptr;
-          if (auto bridgeAttr = recordDecl->getAttr<ObjCBridgeAttr>())
-            bridgedType = bridgeAttr->getBridgedType();
-          else if (auto bridgeAttr =
-                       recordDecl->getAttr<ObjCBridgeMutableAttr>())
-            bridgedType = bridgeAttr->getBridgedType();
-
-          if (bridgedType == S.getNSErrorIdent()) {
-            S.CFError = recordDecl;
-            isCFError = true;
-          }
-        }
-      }
-
       // If this is CFErrorRef*, report it as such.
-      if (isCFError && numNormalPointers == 2 && numTypeSpecifierPointers < 2) {
+      if (numNormalPointers == 2 && numTypeSpecifierPointers < 2 &&
+          S.isCFError(recordDecl)) {
         return PointerDeclaratorKind::CFErrorRefPointer;
       }
       break;
@@ -4092,6 +4069,31 @@ classifyPointerDeclarator(Sema &S, QualType type, Declarator &declarator,
   }
 }
 
+bool Sema::isCFError(RecordDecl *RD) {
+  // If we already know about CFError, test it directly.
+  if (CFError)
+    return CFError == RD;
+
+  // Check whether this is CFError, which we identify based on its bridge to
+  // NSError. CFErrorRef used to be declared with "objc_bridge" but is now
+  // declared with "objc_bridge_mutable", so look for either one of the two
+  // attributes.
+  if (RD->getTagKind() == TTK_Struct) {
+    IdentifierInfo *bridgedType = nullptr;
+    if (auto bridgeAttr = RD->getAttr<ObjCBridgeAttr>())
+      bridgedType = bridgeAttr->getBridgedType();
+    else if (auto bridgeAttr = RD->getAttr<ObjCBridgeMutableAttr>())
+      bridgedType = bridgeAttr->getBridgedType();
+
+    if (bridgedType == getNSErrorIdent()) {
+      CFError = RD;
+      return true;
+    }
+  }
+
+  return false;
+}
+
 static FileID getNullabilityCompletenessCheckFileID(Sema &S,
                                                     SourceLocation loc) {
   // If we're anywhere in a function, method, or closure context, don't perform