swift-module-digester: removing setter from a property is API breaking.

Author: nkcsgexi

include/swift/AST/DiagnosticsModuleDiffer.def

@@ -42,6 +42,8 @@ ERROR(raw_type_change,none,"%0(%1) is now %2 representable", (StringRef, StringR
 
 ERROR(removed_decl,none,"%0 has been removed%select{| (deprecated)}1", (StringRef, bool))
 
+ERROR(removed_setter,none,"%0 has removed its setter", (StringRef))
+
 ERROR(moved_decl,none,"%0 has been moved to %1", (StringRef, StringRef))
 
 ERROR(renamed_decl,none,"%0 has been renamed to %1", (StringRef, StringRef))

test/api-digester/Inputs/cake1.swift

@@ -75,3 +75,7 @@ public protocol AssociatedTypePro {
   associatedtype T2
   associatedtype T3 = C1
 }
+
+public class RemoveSetters {
+  public var Value = 4
+}

test/api-digester/Inputs/cake2.swift

@@ -82,3 +82,8 @@ public protocol AssociatedTypePro {
   associatedtype T2
   associatedtype T3 = C6
 }
+
+public class RemoveSetters {
+  public private(set) var Value = 4
+}
+

test/api-digester/Outputs/Cake-abi.txt

@@ -9,6 +9,7 @@ cake1: Protocol P3 has generic signature change from <τ_0_0 : P1, τ_0_0 : P2>
 cake1: Constructor Somestruct2.init(_:) has been removed
 cake1: Constructor fixedLayoutStruct.init(b:a:) has been removed
 cake1: Func C4.foo() has been removed
+cake1: Var RemoveSetters.Value has removed its setter
 
 /* Moved Decls */
 

test/api-digester/Outputs/Cake.txt

@@ -9,6 +9,7 @@ cake1: Protocol P3 has generic signature change from <Self : P1, Self : P2> to <
 cake1: Constructor Somestruct2.init(_:) has been removed
 cake1: Constructor fixedLayoutStruct.init(b:a:) has been removed
 cake1: Func C4.foo() has been removed
+cake1: Var RemoveSetters.Value has removed its setter
 
 /* Moved Decls */
 

tools/swift-api-digester/ModuleAnalyzerNodes.cpp

@@ -144,6 +144,22 @@ StringRef SDKNodeDecl::getHeaderName() const {
   return llvm::sys::path::filename(Location.split(":").first);
 }
 
+SDKNodeDeclGetter *SDKNodeDeclVar::getGetter() const {
+  if (getChildrenCount() > 1)
+    return cast<SDKNodeDeclGetter>(childAt(1));
+  return nullptr;
+}
+
+SDKNodeDeclSetter *SDKNodeDeclVar::getSetter() const {
+  if (getChildrenCount() > 2)
+    return cast<SDKNodeDeclSetter>(childAt(2));
+  return nullptr;
+}
+
+SDKNodeType *SDKNodeDeclVar::getType() const {
+  return cast<SDKNodeType>(childAt(0));
+}
+
 NodePtr UpdatedNodesMap::findUpdateCounterpart(const SDKNode *Node) const {
   assert(Node->isAnnotatedAs(NodeAnnotation::Updated) && "Not update operation.");
   auto FoundPair = std::find_if(MapImpl.begin(), MapImpl.end(),

tools/swift-api-digester/ModuleAnalyzerNodes.h

@@ -207,7 +207,8 @@ enum class KnownProtocolKind: uint8_t {
 };
 
 class SDKNodeRoot;
-
+class SDKNodeDeclGetter;
+class SDKNodeDeclSetter;
 struct SDKNodeInitInfo;
 
 class SDKNode {
@@ -456,6 +457,9 @@ class SDKNodeDeclVar : public SDKNodeDecl {
   static bool classof(const SDKNode *N);
   bool hasFixedBinaryOrder() const { return FixedBinaryOrder.hasValue(); }
   unsigned getFixedBinaryOrder() const { return *FixedBinaryOrder; }
+  SDKNodeDeclGetter *getGetter() const;
+  SDKNodeDeclSetter *getSetter() const;
+  SDKNodeType *getType() const;
 };
 
 class SDKNodeDeclAbstractFunc : public SDKNodeDecl {

tools/swift-api-digester/ModuleDiagsConsumer.cpp

@@ -33,6 +33,7 @@ enum LocalDiagID : uint32_t {
 static StringRef getCategoryName(uint32_t ID) {
   switch(ID) {
   case LocalDiagID::removed_decl:
+  case LocalDiagID::removed_setter:
     return "/* Removed Decls */";
   case LocalDiagID::moved_decl:
     return "/* Moved Decls */";

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

@@ -886,10 +886,16 @@ class PrunePass : public MatchedNodeListener, public SDKTreeDiffPass {
     }
 
     case SDKNodeKind::DeclVar: {
-      auto LC = Left->getChildren()[0];
-      auto RC = Right->getChildren()[0];
+      auto LVar = cast<SDKNodeDeclVar>(Left);
+      auto RVar = cast<SDKNodeDeclVar>(Right);
+      auto LC = LVar->getType();
+      auto RC = RVar->getType();
       if (!(*LC == *RC))
         foundMatch(LC, RC, NodeMatchReason::Sequential);
+      if (LVar->getSetter() && !RVar->getSetter()) {
+          Ctx.getDiags().diagnose(SourceLoc(), diag::removed_setter,
+                                  LVar->getScreenInfo());
+      }
       break;
     }
     }