[NativePDB] Fix crash in llvm-pdbutil (llvm#164871)

Fix out of buffer read when value of --type-index was too big

Co-authored-by: Alexandre Ganea <[email protected]>

Author: 2 people

llvm/lib/DebugInfo/CodeView/LazyRandomTypeCollection.cpp

@@ -102,7 +102,8 @@ std::optional<CVType> LazyRandomTypeCollection::tryGetType(TypeIndex Index) {
     return std::nullopt;
   }
 
-  assert(contains(Index));
+  if (!contains(Index))
+    return std::nullopt;
   return Records[Index.toArrayIndex()].Type;
 }
 

llvm/test/DebugInfo/PDB/Native/pdb-native-index-overflow.test

@@ -0,0 +1,13 @@
+; Test that the native PDB reader isn't crashed by index value bigger than
+; number of types in TPI or IPI stream
+; RUN: llvm-pdbutil dump %p/../Inputs/empty.pdb --type-index=20000000\
+; RUN:   | FileCheck -check-prefixes=TYPES,NOT_FOUND %s
+; RUN: llvm-pdbutil dump %p/../Inputs/empty.pdb --id-index=20000000\
+; RUN:   | FileCheck -check-prefixes=IDS,NOT_FOUND %s
+
+TYPES:                     Types (TPI Stream)
+IDS:                       Types (IPI Stream)
+NOT_FOUND:============================================================
+NOT_FOUND:  Showing 1 records.
+NOT_FOUND:  Type 0x1312D00 doesn't exist in TPI stream
+