swift-module-digester: diagnose adding/removing @escaping as ABI breakage.

include/swift/AST/DiagnosticsModuleDiffer.def

@@ -80,6 +80,8 @@ ERROR(var_let_changed,none,"%0 changes from %select{var|let}1 to %select{let|var
 
 ERROR(no_longer_open,none,"%0 is no longer open for subclassing", (StringRef))
 
+ERROR(func_type_escaping_changed,none,"%0 has %select{removed|added}2 @escaping in %1", (StringRef, StringRef, bool))
+
 #ifndef DIAG_NO_UNDEF
 # if defined(DIAG)
 #  undef DIAG

test/api-digester/Inputs/cake1.swift

@@ -120,3 +120,8 @@ public class ClassWithOpenMember {
   open var property: Int {get { return 1}}
   open func bar() {}
 }
+
+public class EscapingFunctionType {
+  public func removedEscaping(_ a: @escaping ()->()) {}
+  public func addedEscaping(_ a: ()->()) {}
+}

test/api-digester/Inputs/cake2.swift

@@ -130,3 +130,8 @@ public class ClassWithOpenMember {
   public var property: Int {get { return 1}}
   public func bar() {}
 }
+
+public class EscapingFunctionType {
+  public func removedEscaping(_ a: ()->()) {}
+  public func addedEscaping(_ a: @escaping ()->()) {}
+}

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

@@ -31,6 +31,8 @@ cake1: Constructor S1.init(_:) has parameter 0 type change from Int to Double
 cake1: Func C1.foo2(_:) has parameter 0 type change from Int to () -> ()
 cake1: Func C7.foo(_:_:) has removed default argument from parameter 0
 cake1: Func C7.foo(_:_:) has removed default argument from parameter 1
+cake1: Func EscapingFunctionType.addedEscaping(_:) has added @escaping in parameter 0
+cake1: Func EscapingFunctionType.removedEscaping(_:) has removed @escaping in parameter 0
 cake1: Func Somestruct2.foo1(_:) has parameter 0 type change from C3 to C1
 
 /* Decl Attribute changes */

tools/swift-api-digester/ModuleAnalyzerNodes.cpp

@@ -352,13 +352,19 @@ ArrayRef<DeclAttrKind> SDKNodeDecl::getDeclAttributes() const {
 }
 
 bool SDKNodeDecl::hasAttributeChange(const SDKNodeDecl &Another) const {
-  if (getDeclAttributes().size() != Another.getDeclAttributes().size())
+  std::set<DeclAttrKind> Left(getDeclAttributes().begin(),
-    return true;
+                              getDeclAttributes().end());
-  for (auto K: getDeclAttributes()) {
+  std::set<DeclAttrKind> Right(Another.getDeclAttributes().begin(),
-    if (!Another.hasDeclAttribute(K))
+                               Another.getDeclAttributes().end());
-      return true;
+  return Left != Right;
-  }
+}
-  return false;
+
+bool SDKNodeType::hasAttributeChange(const SDKNodeType &Another) const {
+  std::set<TypeAttrKind> Left(getTypeAttributes().begin(),
+                              getTypeAttributes().end());
+  std::set<TypeAttrKind> Right(Another.getTypeAttributes().begin(),
+                               Another.getTypeAttributes().end());
+  return Left != Right;
 }
 
 SDKNodeDecl *SDKNodeType::getClosestParentDecl() const {
@@ -614,7 +620,7 @@ bool SDKNode::operator==(const SDKNode &Other) const {
     case SDKNodeKind::TypeFunc: {
       auto Left = this->getAs<SDKNodeType>();
       auto Right = (&Other)->getAs<SDKNodeType>();
-      if (!Left->getTypeAttributes().equals(Right->getTypeAttributes()))
+      if (Left->hasAttributeChange(*Right))
         return false;
       if (Left->hasDefaultArgument() != Right->hasDefaultArgument())
         return false;

tools/swift-api-digester/ModuleAnalyzerNodes.h

@@ -348,10 +348,10 @@ class SDKNodeType : public SDKNode {
   bool HasDefaultArg;
 
 protected:
-  bool hasTypeAttribute(TypeAttrKind DAKind) const;
   SDKNodeType(SDKNodeInitInfo Info, SDKNodeKind Kind);
   ~SDKNodeType() = default;
 public:
+  bool hasTypeAttribute(TypeAttrKind DAKind) const;
   KnownTypeKind getTypeKind() const;
   void addTypeAttribute(TypeAttrKind AttrKind);
   ArrayRef<TypeAttrKind> getTypeAttributes() const;
@@ -363,6 +363,7 @@ public:
   bool isTopLevelType() const { return !isa<SDKNodeType>(getParent()); }
   static bool classof(const SDKNode *N);
   virtual void jsonize(json::Output &Out) override;
+  bool hasAttributeChange(const SDKNodeType &Another) const;
 };
 
 class SDKNodeTypeNominal : public SDKNodeType {
@@ -378,7 +379,7 @@ public:
 class SDKNodeTypeFunc : public SDKNodeType {
 public:
   SDKNodeTypeFunc(SDKNodeInitInfo Info);
-  bool isEscaping() const { return !hasTypeAttribute(TypeAttrKind::TAK_noescape); }
+  bool isEscaping() const { return hasTypeAttribute(TypeAttrKind::TAK_noescape); }
   static bool classof(const SDKNode *N);
 };
 

tools/swift-api-digester/ModuleDiagsConsumer.cpp

@@ -46,6 +46,7 @@ static StringRef getCategoryName(uint32_t ID) {
     return "/* Decl Attribute changes */";
   case LocalDiagID::default_arg_removed:
   case LocalDiagID::decl_type_change:
+  case LocalDiagID::func_type_escaping_changed:
     return "/* Type Changes */";
   case LocalDiagID::raw_type_change:
     return "/* RawRepresentable Changes */";

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

@@ -811,14 +811,69 @@ static void diagnoseTypeChange(SDKNode* L, SDKNode* R) {
   auto *RT = dyn_cast<SDKNodeType>(R);
   if (!LT || !RT)
     return;
+  assert(LT->isTopLevelType() == RT->isTopLevelType());
+  if (!LT->isTopLevelType())
+    return;
+  StringRef Descriptor;
+  auto LParent = cast<SDKNodeDecl>(LT->getParent());
+  auto RParent = cast<SDKNodeDecl>(RT->getParent());
+  assert(LParent->getKind() == RParent->getKind());
+  if (LParent->isSDKPrivate())
+    return;
+  switch(LParent->getKind()) {
+  case SDKNodeKind::Root:
+  case SDKNodeKind::TypeNominal:
+  case SDKNodeKind::TypeFunc:
+  case SDKNodeKind::TypeAlias:
+  case SDKNodeKind::DeclType:
+    llvm_unreachable("Type Parent is wrong");
+  case SDKNodeKind::DeclFunction:
+  case SDKNodeKind::DeclConstructor:
+  case SDKNodeKind::DeclGetter:
+  case SDKNodeKind::DeclSetter:
+  case SDKNodeKind::DeclSubscript:
+    Descriptor = SDKNodeDeclAbstractFunc::
+      getTypeRoleDescription(Ctx, LParent->getChildIndex(LT));
+    break;
+  case SDKNodeKind::DeclVar:
+    Descriptor = "declared";
+    break;
+  case SDKNodeKind::DeclTypeAlias:
+    Descriptor = "underlying";
+    break;
+  case SDKNodeKind::DeclAssociatedType:
+    Descriptor = "default";
+    break;
+  }
+
+  if (LT->getPrintedName() != RT->getPrintedName()) {
+    Diags.diagnose(SourceLoc(), diag::decl_type_change, LParent->getScreenInfo(),
+                   Descriptor, LT->getPrintedName(), RT->getPrintedName());
+    return;
+  }
+
   if (LT->hasDefaultArgument() && !RT->hasDefaultArgument()) {
-    auto *Func = cast<SDKNodeDeclAbstractFunc>(LT->getClosestParentDecl());
+    Diags.diagnose(SourceLoc(), diag::default_arg_removed,
-    Diags.diagnose(SourceLoc(), diag::default_arg_removed, Func->getScreenInfo(),
+                   LParent->getScreenInfo(), Descriptor);
-                   Func->getTypeRoleDescription(Ctx, Func->getChildIndex(LT)));
+  }
+  if (LT->getKind() != RT->getKind())
+    return;
+  assert(LT->getKind() == RT->getKind());
+  switch (LT->getKind()) {
+  case SDKNodeKind::TypeFunc: {
+    auto *LFT = cast<SDKNodeTypeFunc>(LT);
+    auto *RFT = cast<SDKNodeTypeFunc>(RT);
+    if (Ctx.checkingABI() && LFT->isEscaping() != RFT->isEscaping()) {
+      Diags.diagnose(SourceLoc(), diag::func_type_escaping_changed,
+                     LParent->getScreenInfo(), Descriptor, LFT->isEscaping());
+    }
+    break;
+  }
+  default:
+    break;
   }
 }
 
-
 // This is first pass on two given SDKNode trees. This pass removes the common part
 // of two versions of SDK, leaving only the changed part.
 class PrunePass : public MatchedNodeListener, public SDKTreeDiffPass {
@@ -1656,7 +1711,6 @@ public:
 
 class DiagnosisEmitter : public SDKNodeVisitor {
   void handle(const SDKNodeDecl *D, NodeAnnotation Anno);
-  void visitType(SDKNodeType *T);
   void visitDecl(SDKNodeDecl *D);
   void visit(NodePtr Node) override;
   SDKNodeDecl *findAddedDecl(const SDKNodeDecl *Node);
@@ -1796,42 +1850,10 @@ void DiagnosisEmitter::visitDecl(SDKNodeDecl *Node) {
     handle(Node, Anno);
 }
 
-void DiagnosisEmitter::visitType(SDKNodeType *Node) {
-  auto *Parent = dyn_cast<SDKNodeDecl>(Node->getParent());
-  if (!Parent || Parent->isSDKPrivate())
-    return;
-  SDKContext &Ctx = Node->getSDKContext();
-  if (Node->isAnnotatedAs(NodeAnnotation::Updated)) {
-    auto *Count = UpdateMap.findUpdateCounterpart(Node)->getAs<SDKNodeType>();
-    StringRef Descriptor;
-    switch (Parent->getKind()) {
-    case SDKNodeKind::DeclConstructor:
-    case SDKNodeKind::DeclFunction:
-    case SDKNodeKind::DeclVar:
-      Descriptor = isa<SDKNodeDeclAbstractFunc>(Parent) ?
-        SDKNodeDeclAbstractFunc::getTypeRoleDescription(Ctx, Parent->getChildIndex(Node)) :
-        Ctx.buffer("declared");
-      if (Node->getPrintedName() != Count->getPrintedName())
-        Diags.diagnose(SourceLoc(), diag::decl_type_change, Parent->getScreenInfo(),
-          Descriptor, Node->getPrintedName(), Count->getPrintedName());
-      break;
-    case SDKNodeKind::DeclAssociatedType:
-      Diags.diagnose(SourceLoc(), diag::decl_type_change, Parent->getScreenInfo(),
-                     "default", Node->getPrintedName(), Count->getPrintedName());
-      break;
-    default:
-      break;
-    }
-  }
-}
-
 void DiagnosisEmitter::visit(NodePtr Node) {
   if (auto *DNode = dyn_cast<SDKNodeDecl>(Node)) {
     visitDecl(DNode);
   }
-  if (auto *TNode = dyn_cast<SDKNodeType>(Node)) {
-    visitType(TNode);
-  }
 }
 
 typedef std::vector<NoEscapeFuncParam> NoEscapeFuncParamVector;