Support importing of ObjC categories from modules.

The initial incentive was to fix a crash when PCH chaining categories
to an interface, but the fix was done in the "modules way" that I hear
is popular with the kids these days.

Each module stores the local chain of categories and we combine them
when the interface is loaded. We also warn if non-dependent modules
introduce duplicate named categories.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138926 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 0 deletions

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 25bff0aba1..a57f3a1388 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -3188,6 +3188,7 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
 
   WriteDeclUpdatesBlocks();
   WriteDeclReplacementsBlock();
+  WriteChainedObjCCategories();
 
   // Some simple statistics
   Record.clear();
@@ -3236,6 +3237,26 @@ void ASTWriter::WriteDeclReplacementsBlock() {
   Stream.EmitRecord(DECL_REPLACEMENTS, Record);
 }
 
+void ASTWriter::WriteChainedObjCCategories() {
+  if (LocalChainedObjCCategories.empty())
+    return;
+
+  RecordData Record;
+  for (SmallVector<ChainedObjCCategoriesData, 16>::iterator
+         I = LocalChainedObjCCategories.begin(),
+         E = LocalChainedObjCCategories.end(); I != E; ++I) {
+    ChainedObjCCategoriesData &Data = *I;
+    serialization::DeclID
+        HeadCatID = getDeclID(Data.Interface->getCategoryList());
+    assert(HeadCatID != 0 && "Category not written ?");
+
+    Record.push_back(Data.InterfaceID);
+    Record.push_back(HeadCatID);
+    Record.push_back(Data.TailCatID);
+  }
+  Stream.EmitRecord(OBJC_CHAINED_CATEGORIES, Record);
+}
+
 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
   Record.push_back(Loc.getRawEncoding());
 }
@@ -4037,4 +4058,17 @@ void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
       D->getMemberSpecializationInfo()->getPointOfInstantiation(), Record);
 }
 
+void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
+                                             const ObjCInterfaceDecl *IFD) {
+  if (IFD->getPCHLevel() == 0)
+    return; // Declaration not imported from PCH.
+  if (CatD->getNextClassCategory() &&
+      CatD->getNextClassCategory()->getPCHLevel() == 0)
+    return; // We already recorded that the tail of a category chain should be
+            // attached to an interface.
+
+  ChainedObjCCategoriesData Data =  { IFD, GetDeclRef(IFD), GetDeclRef(CatD) };
+  LocalChainedObjCCategories.push_back(Data);
+}
+
 ASTSerializationListener::~ASTSerializationListener() { }