[modules] Deserialize CXXCtorInitializer list for a constructor lazily.

Previously we'd deserialize the list of mem-initializers for a constructor when
we deserialized the declaration of the constructor. That could trigger a
significant amount of unnecessary work (pulling in all base classes
recursively, for a start) and was causing problems for the modules buildbot due
to cyclic deserializations. We now deserialize these on demand.

This creates a certain amount of duplication with the handling of
CXXBaseSpecifiers; I'll look into reducing that next.

llvm-svn: 233052

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/Sema/MultiplexExternalSemaSource.cpp b/clang/lib/Sema/MultiplexExternalSemaSource.cpp
index 194c369..bd7e785 100644
--- a/clang/lib/Sema/MultiplexExternalSemaSource.cpp
+++ b/clang/lib/Sema/MultiplexExternalSemaSource.cpp
@@ -86,6 +86,14 @@ CXXBaseSpecifier *MultiplexExternalSemaSource::GetExternalCXXBaseSpecifiers(
   return nullptr;
 }
 
+CXXCtorInitializer **
+MultiplexExternalSemaSource::GetExternalCXXCtorInitializers(uint64_t Offset) {
+  for (auto *S : Sources)
+    if (auto *R = S->GetExternalCXXCtorInitializers(Offset))
+      return R;
+  return nullptr;
+}
+
 bool MultiplexExternalSemaSource::
 FindExternalVisibleDeclsByName(const DeclContext *DC, DeclarationName Name) {
   bool AnyDeclsFound = false;