1 files changed, 11 insertions, 5 deletions
diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index 60530d7f7a00..0f4111514057 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1105,7 +1105,7 @@ void MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata(
 void MetadataLoader::MetadataLoaderImpl::resolveForwardRefsAndPlaceholders(
     PlaceholderQueue &Placeholders) {
   DenseSet<unsigned> Temporaries;
-  while (1) {
+  while (true) {
     // Populate Temporaries with the placeholders that haven't been loaded yet.
     Placeholders.getTemporaries(MetadataList, Temporaries);
 
@@ -1423,15 +1423,21 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     break;
   }
   case bitc::METADATA_STRING_TYPE: {
-    if (Record.size() != 8)
+    if (Record.size() > 9 || Record.size() < 8)
       return error("Invalid record");
 
     IsDistinct = Record[0];
+    bool SizeIs8 = Record.size() == 8;
+    // StringLocationExp (i.e. Record[5]) is added at a later time
+    // than the other fields. The code here enables backward compatibility.
+    Metadata *StringLocationExp = SizeIs8 ? nullptr : getMDOrNull(Record[5]);
+    unsigned Offset = SizeIs8 ? 5 : 6;
     MetadataList.assignValue(
         GET_OR_DISTINCT(DIStringType,
                         (Context, Record[1], getMDString(Record[2]),
                          getMDOrNull(Record[3]), getMDOrNull(Record[4]),
-                         Record[5], Record[6], Record[7])),
+                         StringLocationExp, Record[Offset], Record[Offset + 1],
+                         Record[Offset + 2])),
         NextMetadataNo);
     NextMetadataNo++;
     break;
@@ -1632,7 +1638,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
         Record.size() <= 16 ? true : Record[16],
         Record.size() <= 17 ? false : Record[17],
         Record.size() <= 18 ? 0 : Record[18],
-        Record.size() <= 19 ? 0 : Record[19],
+        Record.size() <= 19 ? false : Record[19],
         Record.size() <= 20 ? nullptr : getMDString(Record[20]),
         Record.size() <= 21 ? nullptr : getMDString(Record[21]));
 
@@ -1675,7 +1681,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
       SPFlags = DISubprogram::toSPFlags(
           /*IsLocalToUnit=*/Record[7], /*IsDefinition=*/Record[8],
           /*IsOptimized=*/Record[14], /*Virtuality=*/Record[11],
-          /*DIFlagMainSubprogram=*/HasOldMainSubprogramFlag);
+          /*IsMainSubprogram=*/HasOldMainSubprogramFlag);
 
     // All definitions should be distinct.
     IsDistinct = (Record[0] & 1) || (SPFlags & DISubprogram::SPFlagDefinition);