Merge pull request swiftlang#19523 from nkcsgexi/class-chain-analysis

swift-module-digester: fix a false positive when diagnosing super class changes.

Author: nkcsgexi

include/swift/IDE/DigesterEnums.def

@@ -109,7 +109,7 @@ KEY(declAttributes)
 KEY(declKind)
 KEY(ownership)
 KEY(superclassUsr)
-KEY(superclassName)
+KEY(superclassNames)
 KEY(hasDefaultArg)
 KEY(conformingProtocols)
 KEY(enumRawTypeName)

test/api-digester/Inputs/cake1.swift

@@ -94,3 +94,5 @@ public class SuperClassRemoval: C3 {}
 
 public class ClassToStruct {}
 public protocol ProtocolToEnum {}
+
+public class SuperClassChange: C7 {}

test/api-digester/Inputs/cake2.swift

@@ -71,6 +71,8 @@ public class C7: P1 {
   public func foo(_ a: Int, _ b: Int) {}
 }
 
+public class C8: C7 {}
+
 public protocol P3: P1, P4 {}
 
 public protocol P4 {}
@@ -101,3 +103,5 @@ public class SuperClassRemoval {}
 
 public struct ClassToStruct {}
 public enum ProtocolToEnum {}
+
+public class SuperClassChange: C8 {}

test/api-digester/Outputs/cake-abi.json

@@ -198,7 +198,9 @@
       "location": "",
       "moduleName": "cake",
       "superclassUsr": "s:4cake2C0C",
-      "superclassName": "C0",
+      "superclassNames": [
+        "C0"
+      ],
       "children": [
         {
           "kind": "Function",

test/api-digester/Outputs/cake.json

@@ -205,7 +205,9 @@
       "location": "",
       "moduleName": "cake",
       "superclassUsr": "s:4cake2C0C",
-      "superclassName": "C0",
+      "superclassNames": [
+        "C0"
+      ],
       "children": [
         {
           "kind": "Function",

test/api-digester/Outputs/clang-module-dump.txt

@@ -12,7 +12,9 @@
       "location": "",
       "moduleName": "Foo",
       "superclassUsr": "c:objc(cs)NSObject",
-      "superclassName": "NSObject",
+      "superclassNames": [
+        "NSObject"
+      ],
       "conformingProtocols": [
         "ObjcProt",
         "NSObjectProtocol"

tools/swift-api-digester/ModuleAnalyzerNodes.cpp

@@ -48,7 +48,7 @@ struct swift::ide::api::SDKNodeInitInfo {
   std::vector<TypeAttrKind> TypeAttrs;
   std::vector<StringRef> ConformingProtocols;
   StringRef SuperclassUsr;
-  StringRef SuperclassName;
+  std::vector<StringRef> SuperclassNames;
   StringRef EnumRawTypeName;
   bool hasDefaultArgument = false;
   StringRef GenericSig;
@@ -101,7 +101,7 @@ SDKNodeTypeAlias::SDKNodeTypeAlias(SDKNodeInitInfo Info):
 
 SDKNodeDeclType::SDKNodeDeclType(SDKNodeInitInfo Info): 
   SDKNodeDecl(Info, SDKNodeKind::DeclType), SuperclassUsr(Info.SuperclassUsr),
-  SuperclassName(Info.SuperclassName),
+  SuperclassNames(Info.SuperclassNames),
   ConformingProtocols(Info.ConformingProtocols),
   EnumRawTypeName(Info.EnumRawTypeName) {}
 
@@ -570,8 +570,12 @@ SDKNode* SDKNode::constructSDKNode(SDKContext &Ctx,
       case KeyKind::KK_superclassUsr:
         Info.SuperclassUsr = GetScalarString(Pair.getValue());
         break;
-      case KeyKind::KK_superclassName:
-        Info.SuperclassName = GetScalarString(Pair.getValue());
+      case KeyKind::KK_superclassNames:
+        assert(Info.SuperclassNames.empty());
+        for (auto &Name : *cast<llvm::yaml::SequenceNode>(Pair.getValue())) {
+          Info.SuperclassNames.push_back(GetScalarString(&Name));
+        }
+        break;
         break;
       case KeyKind::KK_genericSig:
         Info.GenericSig = GetScalarString(Pair.getValue());
@@ -1072,7 +1076,10 @@ SDKNodeInitInfo::SDKNodeInitInfo(SDKContext &Ctx, ValueDecl *VD)
   if (auto *CD = dyn_cast_or_null<ClassDecl>(VD)) {
     if (auto *Super = CD->getSuperclassDecl()) {
       SuperclassUsr = calculateUsr(Ctx, Super);
-      SuperclassName = Super->getName().str();
+      while(Super) {
+        SuperclassNames.push_back(Super->getName().str());
+        Super = Super->getSuperclassDecl();
+      }
     }
   }
 
@@ -1521,10 +1528,10 @@ struct ObjectTraits<SDKNode *> {
           out.mapRequired(getKeyContent(Ctx, KeyKind::KK_superclassUsr).data(),
                           Super);
         }
-        auto SuperName = TD->getSuperClassName();
-        if (!SuperName.empty()) {
-          out.mapRequired(getKeyContent(Ctx, KeyKind::KK_superclassName).data(),
-                          SuperName);
+        auto SuperNames = TD->getClassInheritanceChain();
+        if (!SuperNames.empty()) {
+          out.mapRequired(getKeyContent(Ctx, KeyKind::KK_superclassNames).data(),
+                          SuperNames);
         }
         auto Pros = TD->getAllProtocols();
         if (!Pros.empty()) {

tools/swift-api-digester/ModuleAnalyzerNodes.h

@@ -407,14 +407,17 @@ class SDKNodeVectorViewer::ViewerIterator :
 
 class SDKNodeDeclType : public SDKNodeDecl {
   StringRef SuperclassUsr;
-  StringRef SuperclassName;
+  std::vector<StringRef> SuperclassNames;
   std::vector<StringRef> ConformingProtocols;
   StringRef EnumRawTypeName;
 public:
   SDKNodeDeclType(SDKNodeInitInfo Info);
   static bool classof(const SDKNode *N);
   StringRef getSuperClassUsr() const { return SuperclassUsr; }
-  StringRef getSuperClassName() const { return SuperclassName; }
+  ArrayRef<StringRef> getClassInheritanceChain() const { return SuperclassNames; }
+  StringRef getSuperClassName() const {
+    return SuperclassNames.empty() ? StringRef() : SuperclassNames.front();
+  };
   ArrayRef<StringRef> getAllProtocols() const { return ConformingProtocols; }
 
 #define NOMINAL_TYPE_DECL(ID, PARENT) \

tools/swift-api-digester/swift-api-digester.cpp

@@ -710,9 +710,7 @@ static void diagnoseNominalTypeDeclChange(SDKNodeDeclType *L, SDKNodeDeclType *R
       if (RSuperClass.empty()) {
         Diags.diagnose(SourceLoc(), diag::super_class_removed, L->getScreenInfo(),
                        LSuperClass);
-      } else {
-        // FIXME: This will be a false positive if the new subclass is a subclass
-        // of the old type.
+      } else if (!contains(R->getClassInheritanceChain(), LSuperClass)) {
         Diags.diagnose(SourceLoc(), diag::super_class_changed, L->getScreenInfo(),
                        LSuperClass, RSuperClass);
       }