Apart from storing/retrieving the previous redeclaration from PCH, also store/retrieve the most recent

redeclaration. That way we are sure that the full redeclarations chain is loaded.

When using chained PCHs, first declarations point to the most recent redeclarations in the same PCH.
To address this use a REDECLS_UPDATE_LATEST record block to keep track of which first declarations need
to point to a most recent redeclaration in another PCH.

llvm-svn: 110125

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/lib/Frontend/PCHWriter.cpp b/clang/lib/Frontend/PCHWriter.cpp
index 75592a41c85..776a40940d7 100644
--- a/clang/lib/Frontend/PCHWriter.cpp
+++ b/clang/lib/Frontend/PCHWriter.cpp
@@ -2410,6 +2410,19 @@ void PCHWriter::WritePCHChain(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   WriteIdentifierTable(PP);
   WriteTypeDeclOffsets();
 
+  /// Build a record containing first declarations from a chained PCH and the
+  /// most recent declarations in this PCH that they point to.
+  RecordData FirstLatestDeclIDs;
+  for (FirstLatestDeclMap::iterator
+        I = FirstLatestDecls.begin(), E = FirstLatestDecls.end(); I != E; ++I) {
+    assert(I->first->getPCHLevel() > I->second->getPCHLevel() &&
+           "Expected first & second to be in different PCHs");
+    AddDeclRef(I->first, FirstLatestDeclIDs);
+    AddDeclRef(I->second, FirstLatestDeclIDs);
+  }
+  if (!FirstLatestDeclIDs.empty())
+    Stream.EmitRecord(pch::REDECLS_UPDATE_LATEST, FirstLatestDeclIDs);
+
   // Write the record containing external, unnamed definitions.
   if (!ExternalDefinitions.empty())
     Stream.EmitRecord(pch::EXTERNAL_DEFINITIONS, ExternalDefinitions);