[modules] Add an assert that we properly manage the IsCompleteDefinition flag

on CXXRecordDecls when merging definitions, and make it pass by not trying to
save and restore this flag across AST serialization/deserialization. For
CXXRecordDecls, we have a separate mechanism to manage this.

llvm-svn: 216633

3 files changed, 9 insertions, 3 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 68faeed6a20..5cd57d70d09 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8216,8 +8216,11 @@ void ASTReader::finishPendingActions() {
       }
       
       if (auto RD = dyn_cast<CXXRecordDecl>(D)) {
-        for (auto R : RD->redecls())
+        for (auto R : RD->redecls()) {
+          assert((R == D) == R->isThisDeclarationADefinition() &&
+                 "declaration thinks it's the definition but it isn't");
           cast<CXXRecordDecl>(R)->DefinitionData = RD->DefinitionData;
+        }
       }
 
       continue;
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 0aa29239915..60cc6bd5971 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -489,7 +489,8 @@ ASTDeclReader::RedeclarableResult ASTDeclReader::VisitTagDecl(TagDecl *TD) {
   
   TD->IdentifierNamespace = Record[Idx++];
   TD->setTagKind((TagDecl::TagKind)Record[Idx++]);
-  TD->setCompleteDefinition(Record[Idx++]);
+  if (!isa<CXXRecordDecl>(TD))
+    TD->setCompleteDefinition(Record[Idx++]);
   TD->setEmbeddedInDeclarator(Record[Idx++]);
   TD->setFreeStanding(Record[Idx++]);
   TD->setCompleteDefinitionRequired(Record[Idx++]);
@@ -3426,6 +3427,7 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
         Reader.ReadDeclContextStorage(ModuleFile, ModuleFile.DeclsCursor,
                                           std::make_pair(LexicalOffset, 0),
                                           ModuleFile.DeclContextInfos[RD]);
+        Reader.PendingDefinitions.insert(RD);
       }
 
       auto TSK = (TemplateSpecializationKind)Record[Idx++];
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index cd8f7ddf599..336c86b6d57 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -245,7 +245,8 @@ void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
   VisitTypeDecl(D);
   Record.push_back(D->getIdentifierNamespace());
   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
-  Record.push_back(D->isCompleteDefinition());
+  if (!isa<CXXRecordDecl>(D))
+    Record.push_back(D->isCompleteDefinition());
   Record.push_back(D->isEmbeddedInDeclarator());
   Record.push_back(D->isFreeStanding());
   Record.push_back(D->isCompleteDefinitionRequired());