In the serialized AST format, make the translation unit a "predefined"

declaration that never actually gets serialized. Instead, serialize
the various kinds of update records (lexical decls, visible decls, the
addition of an anonymous namespace) for the translation unit, even if
we're not chaining. This way, we won't have to deal with multiple
loaded translation unit declarations.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137395 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 46 insertions, 5 deletions

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index fe747a5150..5b93de4d30 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -841,7 +841,6 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(TYPE_PACK_EXPANSION);
   RECORD(TYPE_ATTRIBUTED);
   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
-  RECORD(DECL_TRANSLATION_UNIT);
   RECORD(DECL_TYPEDEF);
   RECORD(DECL_ENUM);
   RECORD(DECL_RECORD);
@@ -2810,10 +2809,8 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   ASTContext &Context = SemaRef.Context;
   Preprocessor &PP = SemaRef.PP;
 
-  // The translation unit is the first declaration we'll emit.
-  DeclIDs[Context.getTranslationUnitDecl()] = 1;
-  ++NextDeclID;
-  DeclTypesToEmit.push(Context.getTranslationUnitDecl());
+  // Set up predefined declaration IDs.
+  DeclIDs[Context.getTranslationUnitDecl()] = PREDEF_DECL_TRANSLATION_UNIT_ID;
 
   // Make sure that we emit IdentifierInfos (and any attached
   // declarations) for builtins.
@@ -2942,6 +2939,45 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
   SpecialTypes.push_back(Context.isInt128Installed());
 
+  // We don't start with the translation unit, but with its decls that
+  // don't come from the chained PCH.
+  const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
+  SmallVector<KindDeclIDPair, 64> NewGlobalDecls;
+  for (DeclContext::decl_iterator I = TU->noload_decls_begin(),
+       E = TU->noload_decls_end();
+       I != E; ++I) {
+    if ((*I)->getPCHLevel() == 0)
+      NewGlobalDecls.push_back(std::make_pair((*I)->getKind(), GetDeclRef(*I)));
+    else if ((*I)->isChangedSinceDeserialization())
+      (void)GetDeclRef(*I); // Make sure it's written, but don't record it.
+  }
+  // We also need to write a lexical updates block for the TU.
+  llvm::BitCodeAbbrev *Abv = new llvm::BitCodeAbbrev();
+  Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
+  Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
+  unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(Abv);
+  Record.clear();
+  Record.push_back(TU_UPDATE_LEXICAL);
+  Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
+                            data(NewGlobalDecls));
+  
+  // And a visible updates block for the DeclContexts.
+  Abv = new llvm::BitCodeAbbrev();
+  Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
+  Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
+  Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Fixed, 32));
+  Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
+  UpdateVisibleAbbrev = Stream.EmitAbbrev(Abv);
+  WriteDeclContextVisibleUpdate(TU);
+  
+  // If the translation unit has an anonymous namespace, write it as an
+  // update block.
+  if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
+    ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
+    Record.push_back(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE);
+    AddDeclRef(NS, Record);
+  }
+  
   // Keep writing types and declarations until all types and
   // declarations have been written.
   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, NUM_ALLOWED_ABBREVS_SIZE);
@@ -3025,6 +3061,8 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   if (!KnownNamespaces.empty())
     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
   
+  WriteDeclUpdatesBlocks();
+
   // Some simple statistics
   Record.clear();
   Record.push_back(NumStatements);
@@ -3042,6 +3080,9 @@ void ASTWriter::WriteASTChain(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   ASTContext &Context = SemaRef.Context;
   Preprocessor &PP = SemaRef.PP;
 
+  // Set up predefined declaration IDs.
+  DeclIDs[Context.getTranslationUnitDecl()] = PREDEF_DECL_TRANSLATION_UNIT_ID;
+
   RecordData Record;
   Stream.EnterSubblock(AST_BLOCK_ID, 5);
   WriteMetadata(Context, isysroot, "");