improve comment.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@48083 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Lex/PPLexerChange.cpp b/Lex/PPLexerChange.cpp
index ed4e1eb..c5998c9 100644
--- a/Lex/PPLexerChange.cpp
+++ b/Lex/PPLexerChange.cpp
@@ -29,7 +29,7 @@
//===----------------------------------------------------------------------===//
/// isInPrimaryFile - Return true if we're in the top-level file, not in a
-/// #include.
+/// #include. This looks through macro expansions and active _Pragma lexers.
bool Preprocessor::isInPrimaryFile() const {
if (CurLexer && !CurLexer->Is_PragmaLexer)
return IncludeMacroStack.empty();