1 files changed, 4 insertions, 0 deletions
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 91dc4bdbc90..e950bdf40fa 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2727,6 +2727,10 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
       std::tie(F.SLocEntryBaseID, F.SLocEntryBaseOffset) =
           SourceMgr.AllocateLoadedSLocEntries(F.LocalNumSLocEntries,
                                               SLocSpaceSize);
+      if (!F.SLocEntryBaseID) {
+        Error("ran out of source locations");
+        break;
+      }
       // Make our entry in the range map. BaseID is negative and growing, so
       // we invert it. Because we invert it, though, we need the other end of
       // the range.