Introduce a fast path for the ASTReader's name lookup within a

DeclContext. When the DeclContext is of a kind that can only be
defined once and never updated, we limit the search to the module file
that conatins the lookup table. Provides a 15% speedup in one
modules-heavy source file.

llvm-svn: 173050

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 37577ce0718..2f9e1543c2c 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4780,6 +4780,7 @@ void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
   if (!(!D->isFromASTFile() && cast<Decl>(DC)->isFromASTFile()))
     return; // Not a source decl added to a DeclContext from PCH.
 
+  assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
   AddUpdatedDeclContext(DC);
   UpdatingVisibleDecls.push_back(D);
 }