ABI/API checker: diagnose ObjC name changes as breakages

include/swift/AST/DiagnosticsModuleDiffer.def

@@ -96,6 +96,8 @@ ERROR(decl_new_witness_table_entry,none,"%0 now requires %select{|no}1 new witne
 
 ERROR(new_decl_without_intro,none,"%0 is a new API without @available attribute", (StringRef))
 
+ERROR(objc_name_change,none,"%0 has ObjC name change from %1 to %2", (StringRef, StringRef, StringRef))
+
 #ifndef DIAG_NO_UNDEF
 # if defined(DIAG)
 #  undef DIAG

include/swift/IDE/DigesterEnums.def

@@ -151,6 +151,7 @@ KEY_STRING(IntroiOS, intro_iOS)
 KEY_STRING(IntrotvOS, intro_tvOS)
 KEY_STRING(IntrowatchOS, intro_watchOS)
 KEY_STRING(Introswift, intro_swift)
+KEY_STRING(ObjCName, objc_name)
 
 KEY_STRING_ARR(SuperclassNames, superclassNames)
 KEY_STRING_ARR(ToolArgs, tool_arguments)

test/api-digester/Inputs/cake.swift

@@ -3,6 +3,7 @@
 public protocol P1 {}
 public protocol P2 {}
 public protocol P3: P2, P1 {}
+
 @frozen
 public struct S1: P1 {
   public static func foo1() {}
@@ -123,3 +124,9 @@ public class PlatformIntroClass {}
 
 @available(swift, introduced: 5)
 public class SwiftIntroClass {}
+
+@objc(NewObjCClass)
+public class SwiftObjcClass {
+  @objc(ObjCFool:ObjCA:ObjCB:)
+  public func foo(a:Int, b:Int, c: Int) {}
+}

test/api-digester/Inputs/cake_baseline/cake.swift

@@ -195,3 +195,9 @@ public class Zoo {
 }
 
 public func returnFunctionTypeOwnershipChange() -> (C1) -> () { return { _ in } }
+
+@objc(OldObjCClass)
+public class SwiftObjcClass {
+  @objc(OldObjCFool:OldObjCA:OldObjCB:)
+  public func foo(a:Int, b:Int, c: Int) {}
+}

test/api-digester/Inputs/cake_current/cake.swift

@@ -202,3 +202,9 @@ public class Zoo {
 }
 
 public func returnFunctionTypeOwnershipChange() -> (__owned C1) -> () { return { _ in } }
+
+@objc(NewObjCClass)
+public class SwiftObjcClass {
+  @objc(NewObjCFool:NewObjCA:NewObjCB:)
+  public func foo(a:Int, b:Int, c: Int) {}
+}

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

@@ -27,7 +27,9 @@ cake: InfixOperator ..*.. has been changed to a PrefixOperator
 cake: Protocol ProtocolToEnum has been changed to a Enum
 
 /* Renamed Decls */
+cake: Class SwiftObjcClass has ObjC name change from OldObjCClass to NewObjCClass
 cake: Func S1.foo5(x:y:) has been renamed to Func foo5(x:y:z:)
+cake: Func SwiftObjcClass.foo(a:b:c:) has ObjC name change from OldObjCFool:OldObjCA:OldObjCB: to NewObjCFool:NewObjCA:NewObjCB:
 cake: Struct Somestruct2 has been renamed to Struct NSSomestruct2
 
 /* Type Changes */

test/api-digester/Outputs/Cake.txt

@@ -22,7 +22,9 @@ cake: InfixOperator ..*.. has been changed to a PrefixOperator
 cake: Protocol ProtocolToEnum has been changed to a Enum
 
 /* Renamed Decls */
+cake: Class SwiftObjcClass has ObjC name change from OldObjCClass to NewObjCClass
 cake: Func S1.foo5(x:y:) has been renamed to Func foo5(x:y:z:)
+cake: Func SwiftObjcClass.foo(a:b:c:) has ObjC name change from OldObjCFool:OldObjCA:OldObjCB: to NewObjCFool:NewObjCA:NewObjCB:
 cake: Struct Somestruct2 has been renamed to Struct NSSomestruct2
 
 /* Type Changes */

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

@@ -1431,6 +1431,58 @@
         "Available"
       ]
     },
+    {
+      "kind": "TypeDecl",
+      "name": "SwiftObjcClass",
+      "printedName": "SwiftObjcClass",
+      "children": [
+        {
+          "kind": "Function",
+          "name": "foo",
+          "printedName": "foo(a:b:c:)",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "Void",
+              "printedName": "()"
+            },
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Swift.Int",
+              "usr": "s:Si"
+            },
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Swift.Int",
+              "usr": "s:Si"
+            },
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Swift.Int",
+              "usr": "s:Si"
+            }
+          ],
+          "declKind": "Func",
+          "usr": "c:@M@cake@objc(cs)NewObjCClass(im)ObjCFool:ObjCA:ObjCB:",
+          "moduleName": "cake",
+          "objc_name": "ObjCFool:ObjCA:ObjCB:",
+          "declAttributes": [
+            "ObjC"
+          ],
+          "funcSelfKind": "NonMutating"
+        }
+      ],
+      "declKind": "Class",
+      "usr": "c:@M@cake@objc(cs)NewObjCClass",
+      "moduleName": "cake",
+      "objc_name": "NewObjCClass",
+      "declAttributes": [
+        "ObjC"
+      ]
+    },
     {
       "kind": "TypeDecl",
       "name": "Int",
@@ -1771,5 +1823,5 @@
       ]
     }
   ],
-  "json_format_version": 3
+  "json_format_version": 4
 }

test/api-digester/Outputs/cake.json

@@ -1279,6 +1279,58 @@
         "Available"
       ]
     },
+    {
+      "kind": "TypeDecl",
+      "name": "SwiftObjcClass",
+      "printedName": "SwiftObjcClass",
+      "children": [
+        {
+          "kind": "Function",
+          "name": "foo",
+          "printedName": "foo(a:b:c:)",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "Void",
+              "printedName": "()"
+            },
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Swift.Int",
+              "usr": "s:Si"
+            },
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Swift.Int",
+              "usr": "s:Si"
+            },
+            {
+              "kind": "TypeNominal",
+              "name": "Int",
+              "printedName": "Swift.Int",
+              "usr": "s:Si"
+            }
+          ],
+          "declKind": "Func",
+          "usr": "c:@M@cake@objc(cs)NewObjCClass(im)ObjCFool:ObjCA:ObjCB:",
+          "moduleName": "cake",
+          "objc_name": "ObjCFool:ObjCA:ObjCB:",
+          "declAttributes": [
+            "ObjC"
+          ],
+          "funcSelfKind": "NonMutating"
+        }
+      ],
+      "declKind": "Class",
+      "usr": "c:@M@cake@objc(cs)NewObjCClass",
+      "moduleName": "cake",
+      "objc_name": "NewObjCClass",
+      "declAttributes": [
+        "ObjC"
+      ]
+    },
     {
       "kind": "TypeDecl",
       "name": "Int",
@@ -1622,5 +1674,5 @@
       ]
     }
   ],
-  "json_format_version": 3
+  "json_format_version": 4
 }

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

@@ -31,6 +31,7 @@
           "moduleName": "Foo",
           "genericSig": "<Self where Self : Foo.AnotherObjcProt>",
           "protocolReq": true,
+          "objc_name": "anotherFunctionFromProt",
           "declAttributes": [
             "ObjC"
           ],
@@ -41,6 +42,7 @@
       "declKind": "Protocol",
       "usr": "c:objc(pl)AnotherObjcProt",
       "moduleName": "Foo",
+      "objc_name": "AnotherObjcProt",
       "declAttributes": [
         "ObjC"
       ]
@@ -72,6 +74,7 @@
           "usr": "c:objc(cs)ClangInterface(im)someFunction",
           "moduleName": "Foo",
           "isOpen": true,
+          "objc_name": "someFunction",
           "declAttributes": [
             "ObjC"
           ],
@@ -94,6 +97,7 @@
           "moduleName": "Foo",
           "overriding": true,
           "implicit": true,
+          "objc_name": "init",
           "declAttributes": [
             "Override",
             "ObjC"
@@ -104,6 +108,7 @@
       "usr": "c:objc(cs)ClangInterface",
       "moduleName": "Foo",
       "isOpen": true,
+      "objc_name": "ClangInterface",
       "declAttributes": [
         "ObjC"
       ],
@@ -154,6 +159,7 @@
           "moduleName": "Foo",
           "genericSig": "<Self where Self : Foo.ObjcProt>",
           "protocolReq": true,
+          "objc_name": "someFunctionFromProt",
           "declAttributes": [
             "ObjC"
           ],
@@ -164,10 +170,11 @@
       "declKind": "Protocol",
       "usr": "c:objc(pl)ObjcProt",
       "moduleName": "Foo",
+      "objc_name": "ObjcProt",
       "declAttributes": [
         "ObjC"
       ]
     }
   ],
-  "json_format_version": 3
+  "json_format_version": 4
 }

test/api-digester/Outputs/empty-baseline.json

@@ -2,5 +2,5 @@
   "kind": "Root",
   "name": "TopLevel",
   "printedName": "TopLevel",
-  "json_format_version": 3
+  "json_format_version": 4
 }

tools/swift-api-digester/ModuleAnalyzerNodes.cpp

@@ -109,7 +109,8 @@ SDKNodeDecl::SDKNodeDecl(SDKNodeInitInfo Info, SDKNodeKind Kind)
         SugaredGenericSig(Info.SugaredGenericSig),
         FixedBinaryOrder(Info.FixedBinaryOrder),
         introVersions({Info.IntromacOS, Info.IntroiOS, Info.IntrotvOS,
-                       Info.IntrowatchOS, Info.Introswift}){}
+                       Info.IntrowatchOS, Info.Introswift}),
+        ObjCName(Info.ObjCName) {}
 
 SDKNodeType::SDKNodeType(SDKNodeInitInfo Info, SDKNodeKind Kind):
   SDKNode(Info, Kind), TypeAttributes(Info.TypeAttrs),
@@ -915,6 +916,8 @@ static bool isSDKNodeEqual(SDKContext &Ctx, const SDKNode &L, const SDKNode &R)
         return false;
       if (Left->isInternal() != Right->isInternal())
         return false;
+      if (Left->getObjCName() != Right->getObjCName())
+        return false;
       if (Left->hasFixedBinaryOrder() != Right->hasFixedBinaryOrder())
         return false;
       if (Left->hasFixedBinaryOrder()) {
@@ -1252,6 +1255,16 @@ StringRef SDKContext::getLanguageIntroVersion(Decl *D) {
   return getLanguageIntroVersion(D->getDeclContext()->getAsDecl());
 }
 
+StringRef SDKContext::getObjcName(Decl *D) {
+  if (auto *OC = D->getAttrs().getAttribute<ObjCAttr>()) {
+    if (OC->getName().hasValue()) {
+      SmallString<32> Buffer;
+      return buffer(OC->getName()->getString(Buffer));
+    }
+  }
+  return StringRef();
+}
+
 SDKNodeInitInfo::SDKNodeInitInfo(SDKContext &Ctx, Type Ty, TypeInitInfo Info) :
     Ctx(Ctx), Name(getTypeName(Ctx, Ty, Info.IsImplicitlyUnwrappedOptional)),
     PrintedName(getPrintedName(Ctx, Ty, Info.IsImplicitlyUnwrappedOptional)),
@@ -1278,6 +1291,7 @@ SDKNodeInitInfo::SDKNodeInitInfo(SDKContext &Ctx, Decl *D):
       IntrotvOS(Ctx.getPlatformIntroVersion(D, PlatformKind::tvOS)),
       IntrowatchOS(Ctx.getPlatformIntroVersion(D, PlatformKind::watchOS)),
       Introswift(Ctx.getLanguageIntroVersion(D)),
+      ObjCName(Ctx.getObjcName(D)),
       IsImplicit(D->isImplicit()),
       IsDeprecated(D->getAttrs().getDeprecated(D->getASTContext())),
       IsABIPlaceholder(isABIPlaceholderRecursive(D)) {
@@ -1901,6 +1915,7 @@ void SDKNodeDecl::jsonize(json::Output &out) {
   output(out, KeyKind::KK_intro_tvOS, introVersions.tvos);
   output(out, KeyKind::KK_intro_watchOS, introVersions.watchos);
   output(out, KeyKind::KK_intro_swift, introVersions.swift);
+  output(out, KeyKind::KK_objc_name, ObjCName);
   out.mapOptional(getKeyContent(Ctx, KeyKind::KK_declAttributes).data(), DeclAttributes);
   out.mapOptional(getKeyContent(Ctx, KeyKind::KK_fixedbinaryorder).data(), FixedBinaryOrder);
   // Strong reference is implied, no need for serialization.

tools/swift-api-digester/ModuleAnalyzerNodes.h

@@ -62,7 +62,7 @@ namespace api {
 ///
 /// When the json format changes in a way that requires version-specific handling, this number should be incremented.
 /// This ensures we could have backward compatibility so that version changes in the format won't stop the checker from working.
-const uint8_t DIGESTER_JSON_VERSION = 3; // Use fully qualifed type names for all json outputs
+const uint8_t DIGESTER_JSON_VERSION = 4; // Add objc_name field
 const uint8_t DIGESTER_JSON_DEFAULT_VERSION = 0; // Use this version number for files before we have a version number in json.
 
 class SDKNode;
@@ -172,7 +172,8 @@ class SDKContext {
 
   CheckerOptions Opts;
   std::vector<BreakingAttributeInfo> BreakingAttrs;
-
+  // The common version of two ABI/API descriptors under comparison.
+  Optional<uint8_t> CommonVersion;
 public:
   // Define the set of known identifiers.
 #define IDENTIFIER_WITH_NAME(Name, IdStr) StringRef Id_##Name = IdStr;
@@ -204,8 +205,19 @@ class SDKContext {
   DiagnosticEngine &getDiags() {
     return Diags;
   }
+  void setCommonVersion(uint8_t Ver) {
+    assert(!CommonVersion.hasValue());
+    CommonVersion = Ver;
+  }
+  uint8_t getCommonVersion() const {
+    return *CommonVersion;
+  }
+  bool commonVersionAtLeast(uint8_t Ver) const {
+    return getCommonVersion() >= Ver;
+  }
   StringRef getPlatformIntroVersion(Decl *D, PlatformKind Kind);
   StringRef getLanguageIntroVersion(Decl *D);
+  StringRef getObjcName(Decl *D);
   bool isEqual(const SDKNode &Left, const SDKNode &Right);
   bool checkingABI() const { return Opts.ABI; }
   AccessLevel getAccessLevel(const ValueDecl *VD) const;
@@ -343,6 +355,7 @@ class SDKNodeDecl: public SDKNode {
   StringRef SugaredGenericSig;
   Optional<uint8_t> FixedBinaryOrder;
   PlatformIntroVersion introVersions;
+  StringRef ObjCName;
 
 protected:
   SDKNodeDecl(SDKNodeInitInfo Info, SDKNodeKind Kind);
@@ -379,6 +392,7 @@ class SDKNodeDecl: public SDKNode {
   bool hasFixedBinaryOrder() const { return FixedBinaryOrder.hasValue(); }
   uint8_t getFixedBinaryOrder() const { return *FixedBinaryOrder; }
   PlatformIntroVersion getIntroducingVersion() const { return introVersions; }
+  StringRef getObjCName() const { return ObjCName; }
   virtual void jsonize(json::Output &Out) override;
   virtual void diagnose(SDKNode *Right) override;
 

tools/swift-api-digester/ModuleDiagsConsumer.cpp

@@ -38,6 +38,7 @@ static StringRef getCategoryName(uint32_t ID) {
   case LocalDiagID::decl_kind_changed:
     return "/* Moved Decls */";
   case LocalDiagID::renamed_decl:
+  case LocalDiagID::objc_name_change:
     return "/* Renamed Decls */";
   case LocalDiagID::decl_attr_change:
   case LocalDiagID::decl_new_attr: