Adding an assert to help catch possible buffer underruns.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195024 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 93e9a59..9d79551 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -1757,6 +1757,10 @@
SourceLocation SourceManager::translateLineCol(FileID FID,
unsigned Line,
unsigned Col) const {
+ // Lines are used as a one-based index into a zero-based array. This assert
+ // checks for possible buffer underruns.
+ assert(Line != 0 && "Passed a zero-based line");
+
if (FID.isInvalid())
return SourceLocation();