[PCH] When completing an objc forward reference, do not serialize the chain of its categories because

it is going to be rewritten (and the chain will be serialized again), otherwise we may form a cycle in its
categories list when deserializing.

Also introduce ASTMutationListener::CompletedObjCForwardRef to notify that a forward reference
was completed; using Decl's isChangedSinceDeserialization/setChangedSinceDeserialization
is bug inducing and kinda gross, we should phase it out.

Fixes infinite loop in rdar://10418538.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144465 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 16 deletions

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index deaec02271..a98c4cc82b 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -2995,7 +2995,6 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   // Resolve any declaration pointers within the declaration updates block and
   // chained Objective-C categories block to declaration IDs.
   ResolveDeclUpdatesBlocks();
-  ResolveChainedObjCCategories();
   
   // Form the record of special types.
   RecordData SpecialTypes;
@@ -3183,7 +3182,7 @@ void ASTWriter::ResolveDeclUpdatesBlocks() {
     const Decl *D = I->first;
     UpdateRecord &URec = I->second;
     
-    if (DeclsToRewrite.count(D))
+    if (isRewritten(D))
       continue; // The decl will be written completely
 
     unsigned Idx = 0, N = URec.size();
@@ -3216,7 +3215,7 @@ void ASTWriter::WriteDeclUpdatesBlocks() {
     const Decl *D = I->first;
     UpdateRecord &URec = I->second;
 
-    if (DeclsToRewrite.count(D))
+    if (isRewritten(D))
       continue; // The decl will be written completely,no need to store updates.
 
     uint64_t Offset = Stream.GetCurrentBitNo();
@@ -3243,17 +3242,6 @@ void ASTWriter::WriteDeclReplacementsBlock() {
   Stream.EmitRecord(DECL_REPLACEMENTS, Record);
 }
 
-void ASTWriter::ResolveChainedObjCCategories() {
-  for (SmallVector<ChainedObjCCategoriesData, 16>::iterator
-       I = LocalChainedObjCCategories.begin(),
-       E = LocalChainedObjCCategories.end(); I != E; ++I) {
-    ChainedObjCCategoriesData &Data = *I;
-    Data.InterfaceID = GetDeclRef(Data.Interface);
-    Data.TailCategoryID = GetDeclRef(Data.TailCategory);
-  }
-
-}
-
 void ASTWriter::WriteChainedObjCCategories() {
   if (LocalChainedObjCCategories.empty())
     return;
@@ -3263,13 +3251,16 @@ void ASTWriter::WriteChainedObjCCategories() {
          I = LocalChainedObjCCategories.begin(),
          E = LocalChainedObjCCategories.end(); I != E; ++I) {
     ChainedObjCCategoriesData &Data = *I;
+    if (isRewritten(Data.Interface))
+      continue;
+
     serialization::DeclID
         HeadCatID = getDeclID(Data.Interface->getCategoryList());
     assert(HeadCatID != 0 && "Category not written ?");
 
-    Record.push_back(Data.InterfaceID);
+    Record.push_back(GetDeclRef(Data.Interface));
     Record.push_back(HeadCatID);
-    Record.push_back(Data.TailCategoryID);
+    Record.push_back(GetDeclRef(Data.TailCategory));
   }
   Stream.EmitRecord(OBJC_CHAINED_CATEGORIES, Record);
 }
@@ -4136,3 +4127,11 @@ void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
   ChainedObjCCategoriesData Data =  { IFD, CatD, 0, 0 };
   LocalChainedObjCCategories.push_back(Data);
 }
+
+void ASTWriter::CompletedObjCForwardRef(const ObjCContainerDecl *D) {
+  assert(!WritingAST && "Already writing the AST!");
+  if (!D->isFromASTFile())
+    return; // Declaration not imported from PCH.
+
+  RewriteDecl(D);
+}