[AST] Only store the needed data in WhileStmt

Don't store the data for the condition variable if not needed.
This cuts the size of WhileStmt by up to a pointer.
The order of the children is kept the same.

Differential Revision: https://reviews.llvm.org/D53715

Reviewed By: rjmccall

llvm-svn: 345597

1 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 396cc1c2d05..3d0297153d8 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -183,9 +183,15 @@ void ASTStmtWriter::VisitSwitchStmt(SwitchStmt *S) {
 
 void ASTStmtWriter::VisitWhileStmt(WhileStmt *S) {
   VisitStmt(S);
-  Record.AddDeclRef(S->getConditionVariable());
+
+  bool HasVar = S->getConditionVariableDeclStmt() != nullptr;
+  Record.push_back(HasVar);
+
   Record.AddStmt(S->getCond());
   Record.AddStmt(S->getBody());
+  if (HasVar)
+    Record.AddDeclRef(S->getConditionVariable());
+
   Record.AddSourceLocation(S->getWhileLoc());
   Code = serialization::STMT_WHILE;
 }