[modules] If loading a .pcm file would cause us to run out of source locations, attempt to fail more gracefully. (No test; this requires >= 4GB of preprocessed input...)

llvm-svn: 244822

2 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index c0b045331dd..6c2bd7d2332 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -484,10 +484,12 @@ std::pair<int, unsigned>
 SourceManager::AllocateLoadedSLocEntries(unsigned NumSLocEntries,
                                          unsigned TotalSize) {
   assert(ExternalSLocEntries && "Don't have an external sloc source");
+  // Make sure we're not about to run out of source locations.
+  if (CurrentLoadedOffset - TotalSize < NextLocalOffset)
+    return std::make_pair(0, 0);
   LoadedSLocEntryTable.resize(LoadedSLocEntryTable.size() + NumSLocEntries);
   SLocEntryLoaded.resize(LoadedSLocEntryTable.size());
   CurrentLoadedOffset -= TotalSize;
-  assert(CurrentLoadedOffset >= NextLocalOffset && "Out of source locations");
   int ID = LoadedSLocEntryTable.size();
   return std::make_pair(-ID - 1, CurrentLoadedOffset);
 }
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.