Merge commit 'd20ae6985438' from apple/stable/20200108 into swift/master-rebranch

Author: git apple-llvm automerger

clang/include/clang/AST/DeclObjC.h

@@ -1196,6 +1196,7 @@ class ObjCContainerDecl : public NamedDecl, public DeclContext {
 class ObjCInterfaceDecl : public ObjCContainerDecl
                         , public Redeclarable<ObjCInterfaceDecl> {
   friend class ASTContext;
+  friend class ASTReader;
 
   /// TypeForDecl - This indicates the Type object that represents this
   /// TypeDecl.  It is a cache maintained by ASTContext::getObjCInterfaceType
@@ -1253,6 +1254,12 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
     /// One of the \c InheritedDesignatedInitializersState enumeratos.
     mutable unsigned InheritedDesignatedInitializers : 2;
 
+    /// Tracks whether a ODR hash has been computed for this interface.
+    unsigned HasODRHash : 1;
+
+    /// A hash of parts of the class to help in ODR checking.
+    unsigned ODRHash = 0;
+
     /// The location of the last location in this declaration, before
     /// the properties/methods. For example, this will be the '>', '}', or
     /// identifier,
@@ -1261,7 +1268,7 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
     DefinitionData()
         : ExternallyCompleted(false), IvarListMissingImplementation(true),
           HasDesignatedInitializers(false),
-          InheritedDesignatedInitializers(IDI_Unknown) {}
+          InheritedDesignatedInitializers(IDI_Unknown), HasODRHash(false) {}
   };
 
   /// The type parameters associated with this class, if any.
@@ -1946,7 +1953,14 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == ObjCInterface; }
 
+  /// Get precomputed ODRHash or add a new one.
+  unsigned getODRHash();
+
 private:
+  /// True if a valid hash is stored in ODRHash.
+  bool hasODRHash() const;
+  void setHasODRHash(bool Hash = true);
+
   const ObjCInterfaceDecl *findInterfaceWithDesignatedInitializers() const;
   bool inheritsDesignatedInitializers() const;
 };

clang/include/clang/AST/ODRHash.h

@@ -59,6 +59,10 @@ class ODRHash {
   // method compares more information than the AddDecl class.
   void AddRecordDecl(const RecordDecl *Record);
 
+  // Use this for ODR checking ObjC interfaces. This
+  // method compares more information than the AddDecl class.
+  void AddObjCInterfaceDecl(const ObjCInterfaceDecl *Record);
+
   // Use this for ODR checking functions between modules.  This method compares
   // more information than the AddDecl class.  SkipBody will process the
   // hash as if the function has no body.

clang/include/clang/Basic/DiagnosticSerializationKinds.td

@@ -153,6 +153,21 @@ def note_module_odr_violation_definition_data : Note <
   "%ordinal2 base class %3 with "
   "%select{public|protected|private|no}4 access specifier}1">;
 
+def err_module_odr_violation_obj_interface_definition_data : Error <
+  "%q0 has different definitions in different modules; first difference is "
+  "%select{definition in module '%2'|defined here}1 found "
+  "%select{"
+  "%select{no super class|super class with type %5}4|"
+  "%4 referenced %plural{1:protocol|:protocols}4|"
+  "}3">;
+
+def note_module_odr_violation_obj_interface_definition_data : Note <
+  "but in '%0' found "
+  "%select{"
+  "%select{no super class|super class with type %3}2|"
+  "%2 referenced %plural{1:protocol|:protocols}2|"
+  "}1">;
+
 def err_module_odr_violation_template_parameter : Error <
   "%q0 has different definitions in different modules; first difference is "
   "%select{definition in module '%2'|defined here}1 found "

clang/include/clang/Serialization/ASTReader.h

@@ -13,6 +13,7 @@
 #ifndef LLVM_CLANG_SERIALIZATION_ASTREADER_H
 #define LLVM_CLANG_SERIALIZATION_ASTREADER_H
 
+#include "clang/AST/DeclObjC.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
@@ -1087,6 +1088,8 @@ class ASTReader
 
   using DataPointers =
       std::pair<CXXRecordDecl *, struct CXXRecordDecl::DefinitionData *>;
+  using IDDataPointers = std::pair<ObjCInterfaceDecl *,
+                                   struct ObjCInterfaceDecl::DefinitionData *>;
 
   /// Record definitions in which we found an ODR violation.
   llvm::SmallDenseMap<CXXRecordDecl *, llvm::SmallVector<DataPointers, 2>, 2>
@@ -1104,6 +1107,11 @@ class ASTReader
   llvm::SmallDenseMap<RecordDecl *, llvm::SmallVector<RecordDecl *, 2>, 2>
       PendingRecordOdrMergeFailures;
 
+  /// ObjCInterfaceDecl in which we found an ODR violation.
+  llvm::SmallDenseMap<ObjCInterfaceDecl *, llvm::SmallVector<IDDataPointers, 2>,
+                      2>
+      PendingObjCInterfaceOdrMergeFailures;
+
   /// DeclContexts in which we have diagnosed an ODR violation.
   llvm::SmallPtrSet<DeclContext*, 2> DiagnosedOdrMergeFailures;
 

clang/lib/AST/DeclObjC.cpp

@@ -16,6 +16,7 @@
 #include "clang/AST/Attr.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclBase.h"
+#include "clang/AST/ODRHash.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/Type.h"
 #include "clang/AST/TypeLoc.h"
@@ -771,6 +772,33 @@ ObjCMethodDecl *ObjCInterfaceDecl::lookupPrivateMethod(
   return Method;
 }
 
+unsigned ObjCInterfaceDecl::getODRHash() {
+  assert(hasDefinition() && "ODRHash only for records with definitions");
+
+  // Previously calculated hash is stored in DefinitionData.
+  if (hasODRHash())
+    return data().ODRHash;
+
+  // Only calculate hash on first call of getODRHash per record.
+  class ODRHash Hash;
+  Hash.AddObjCInterfaceDecl(getDefinition());
+  setHasODRHash();
+  data().ODRHash = Hash.CalculateHash();
+
+  return data().ODRHash;
+}
+
+bool ObjCInterfaceDecl::hasODRHash() const {
+  if (!hasDefinition())
+    return false;
+  return data().HasODRHash;
+}
+
+void ObjCInterfaceDecl::setHasODRHash(bool Hash) {
+  assert(hasDefinition() && "Cannot set ODRHash without definition");
+  data().HasODRHash = Hash;
+}
+
 //===----------------------------------------------------------------------===//
 // ObjCMethodDecl
 //===----------------------------------------------------------------------===//

clang/lib/AST/ODRHash.cpp

@@ -464,6 +464,27 @@ void ODRHash::AddSubDecl(const Decl *D) {
   ODRDeclVisitor(ID, *this).Visit(D);
 }
 
+void ODRHash::AddObjCInterfaceDecl(const ObjCInterfaceDecl *IF) {
+  AddDecl(IF);
+
+  auto *SuperClass = IF->getSuperClass();
+  AddBoolean(SuperClass);
+  if (SuperClass)
+    ID.AddInteger(SuperClass->getODRHash());
+  ID.AddInteger(IF->getReferencedProtocols().size());
+
+  // Filter out sub-Decls which will not be processed in order to get an
+  // accurate count of Decl's.
+  llvm::SmallVector<const Decl *, 16> Decls;
+  for (Decl *SubDecl : IF->decls())
+    if (isWhitelistedDecl(SubDecl, IF))
+      Decls.push_back(SubDecl);
+
+  ID.AddInteger(Decls.size());
+  for (auto *SubDecl : Decls)
+    AddSubDecl(SubDecl);
+}
+
 void ODRHash::AddRecordDecl(const RecordDecl *Record) {
   AddDecl(Record);