[PCH] Make sure that all newly introduced visible decls in a DeclContext

coming from an AST file are registered for serialization.

A static data member instantiation of in a chained PCH could be missed
when serializing decls; the result was that when emitting the visible decls
map of its DeclContext, we would use a DeclID that was not actually emitted,
leading to crashes or hangs.

Fix this by making sure such decls are always registered for serialization.
Also introduce extra sanity checks to make sure we don't register new
declarations or types after we have serialized the types/decls block.

rdar://11728990

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159550 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 24 insertions, 2 deletions

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 17fef95b6f..8ab1737472 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -3140,7 +3140,8 @@ void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
 
 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream)
   : Stream(Stream), Context(0), PP(0), Chain(0), WritingModule(0),
-    WritingAST(false), ASTHasCompilerErrors(false),
+    WritingAST(false), DoneWritingDeclsAndTypes(false),
+    ASTHasCompilerErrors(false),
     FirstDeclID(NUM_PREDEF_DECL_IDS), NextDeclID(FirstDeclID),
     FirstTypeID(NUM_PREDEF_TYPE_IDS), NextTypeID(FirstTypeID),
     FirstIdentID(NUM_PREDEF_IDENT_IDS), NextIdentID(FirstIdentID), 
@@ -3400,7 +3401,15 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
       Record.push_back(reinterpret_cast<uint64_t>(NS));
     }
   }
-  
+
+  // Make sure visible decls, added to DeclContexts previously loaded from
+  // an AST file, are registered for serialization.
+  for (SmallVector<const Decl *, 16>::iterator
+         I = UpdatingVisibleDecls.begin(),
+         E = UpdatingVisibleDecls.end(); I != E; ++I) {
+    GetDeclRef(*I);
+  }
+
   // Resolve any declaration pointers within the declaration updates block.
   ResolveDeclUpdatesBlocks();
   
@@ -3433,6 +3442,8 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   }
   Stream.ExitBlock();
 
+  DoneWritingDeclsAndTypes = true;
+
   WriteFileDeclIDsMap();
   WriteSourceManagerBlock(Context.getSourceManager(), PP, isysroot);
   WriteComments();
@@ -3819,6 +3830,11 @@ TypeIdx ASTWriter::GetOrCreateTypeIdx(QualType T) {
 
   TypeIdx &Idx = TypeIdxs[T];
   if (Idx.getIndex() == 0) {
+    if (DoneWritingDeclsAndTypes) {
+      assert(0 && "New type seen after serializing all the types to emit!");
+      return TypeIdx();
+    }
+
     // We haven't seen this type before. Assign it a new ID and put it
     // into the queue of types to emit.
     Idx = TypeIdx(NextTypeID++);
@@ -3856,6 +3872,11 @@ DeclID ASTWriter::GetDeclRef(const Decl *D) {
   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
   DeclID &ID = DeclIDs[D];
   if (ID == 0) {
+    if (DoneWritingDeclsAndTypes) {
+      assert(0 && "New decl seen after serializing all the decls to emit!");
+      return 0;
+    }
+
     // We haven't seen this declaration before. Give it a new ID and
     // enqueue it in the list of declarations to emit.
     ID = NextDeclID++;
@@ -4477,6 +4498,7 @@ void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
     return; // Not a source decl added to a DeclContext from PCH.
 
   AddUpdatedDeclContext(DC);
+  UpdatingVisibleDecls.push_back(D);
 }
 
 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {