[Clang importer] Allow a CF type spelled with "void *".

There wasn't any justification for the "const" restriction. Fixes
rdar://problem/24821660.

Author: DougGregor

lib/ClangImporter/CFTypeInfo.cpp

@@ -89,10 +89,10 @@ CFPointeeInfo::classifyTypedef(const clang::TypedefNameDecl *typedefDecl) {
             isWhitelistedCFTypeName(typedefDecl->getName())) {
           return forRecord(isConst, record->getDecl());
         }
-      } else if (isConst && pointee->isVoidType()) {
+      } else if (pointee->isVoidType()) {
         if (typedefDecl->hasAttr<clang::ObjCBridgeAttr>() ||
             isWhitelistedCFTypeName(typedefDecl->getName())) {
-          return forConstVoid();
+          return isConst ? forConstVoid() : forVoid();
         }
       }
     }

lib/ClangImporter/CFTypeInfo.h

@@ -59,6 +59,14 @@ class CFPointeeInfo {
     return info;
   }
 
+  static CFPointeeInfo forVoid() {
+    CFPointeeInfo info;
+    info.IsValid = true;
+    info.IsConst = false;
+    info.Decl = nullptr;
+    return info;
+  }
+
   static CFPointeeInfo forInvalid() {
     CFPointeeInfo info;
     info.IsValid = false;
@@ -73,7 +81,7 @@ class CFPointeeInfo {
 
   bool isConst() const { return IsConst; }
 
-  bool isConstVoid() const {
+  bool isVoid() const {
     assert(isValid());
     return Decl.isNull();
   }

lib/ClangImporter/IAMInference.cpp

@@ -472,7 +472,7 @@ class IAMInference {
               typedefType->getDecl()->getCanonicalDecl())) {
         if (pointeeInfo.isRecord() || pointeeInfo.isTypedef())
           return {typedefType->getDecl()->getCanonicalDecl()};
-        assert(pointeeInfo.isConstVoid() && "no other type");
+        assert(pointeeInfo.isVoid() && "no other type");
         return {};
       }
       qt = qt.getSingleStepDesugaredType(clangSema.getASTContext());

lib/ClangImporter/ImportDecl.cpp

@@ -1550,9 +1550,9 @@ namespace {
               return typealias;
             }
 
-            // If the pointee is 'const void', 'CFTypeRef', bring it
+            // If the pointee is 'void', 'CFTypeRef', bring it
             // in specifically as AnyObject.
-            if (pointee.isConstVoid()) {
+            if (pointee.isVoid()) {
               auto proto = Impl.SwiftContext.getProtocol(
                                                KnownProtocolKind::AnyObject);
               if (!proto)

test/ClangModules/Inputs/custom-modules/CoreCooling.h

@@ -48,3 +48,6 @@ void CCRefrigeratorCreateIndirect(CCRefrigeratorRef * __nullable __attribute__((
 // Note that the fridge parameter is incorrectly annotated.
 void CCRefrigeratorGetPowerSupplyIndirect(CCRefrigeratorRef __attribute__((cf_returns_not_retained)) fridge, CCPowerSupplyRef * __nonnull __attribute__((cf_returns_not_retained)) outPower);
 void CCRefrigeratorGetItemUnaudited(CCRefrigeratorRef fridge, unsigned index, CCItemRef *outItem);
+
+typedef void *CFNonConstVoidRef __attribute__((objc_bridge(id)));
+CFNonConstVoidRef CFNonConstBottom();

test/ClangModules/cf.swift

@@ -144,3 +144,8 @@ func nameCollisions() {
   np = np2
   np2 = np
 }
+
+func testNonConstVoid() {
+  let value: Unmanaged<CFNonConstVoidRef> = CFNonConstBottom()!
+  assertUnmanaged(value)
+}