[Lldb-commits] [lldb] [llvm] [lldb][NativePDB] Fix crash in debugger when PDB has bad type index value (PR #166455)

[Vladimir Gorsunov via lldb-commits]

https://github.com/gv updated https://github.com/llvm/llvm-project/pull/166455

>From ead6177350c54e094d4281fe48914e70926c6a8c Mon Sep 17 00:00:00 2001
From: Vladimir Gorsunov <gorsunov at gmail.com>
Date: Tue, 4 Nov 2025 23:44:08 +0200
Subject: [PATCH] [lldb][NativePDB] Fix crash in debugger when PDB has bad type
 index value

Fix crash when an inline site record in the PDB file contains type
index which is out of bounds
---
 .../SymbolFile/NativePDB/SymbolFileNativePDB.cpp  | 14 +++++++++-----
 .../DebugInfo/CodeView/LazyRandomTypeCollection.h |  2 +-
 .../CodeView/LazyRandomTypeCollection.cpp         | 15 ++++++++++-----
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
index aaec1600dacff..8be6dd196c07c 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -1719,19 +1719,23 @@ void SymbolFileNativePDB::ParseInlineSite(PdbCompilandSymId id,
   }
 
   // Get the inlined function name.
-  CVType inlinee_cvt = m_index->ipi().getType(inline_site.Inlinee);
   std::string inlinee_name;
-  if (inlinee_cvt.kind() == LF_MFUNC_ID) {
+  llvm::Expected<CVType> inlinee_cvt =
+      m_index->ipi().typeCollection().getTypeOrError(inline_site.Inlinee);
+  if (!inlinee_cvt) {
+    inlinee_name = "[error reading function name: " +
+                   llvm::toString(inlinee_cvt.takeError()) + "]";
+  } else if (inlinee_cvt->kind() == LF_MFUNC_ID) {
     MemberFuncIdRecord mfr;
     cantFail(
-        TypeDeserializer::deserializeAs<MemberFuncIdRecord>(inlinee_cvt, mfr));
+        TypeDeserializer::deserializeAs<MemberFuncIdRecord>(*inlinee_cvt, mfr));
     LazyRandomTypeCollection &types = m_index->tpi().typeCollection();
     inlinee_name.append(std::string(types.getTypeName(mfr.ClassType)));
     inlinee_name.append("::");
     inlinee_name.append(mfr.getName().str());
-  } else if (inlinee_cvt.kind() == LF_FUNC_ID) {
+  } else if (inlinee_cvt->kind() == LF_FUNC_ID) {
     FuncIdRecord fir;
-    cantFail(TypeDeserializer::deserializeAs<FuncIdRecord>(inlinee_cvt, fir));
+    cantFail(TypeDeserializer::deserializeAs<FuncIdRecord>(*inlinee_cvt, fir));
     TypeIndex parent_idx = fir.getParentScope();
     if (!parent_idx.isNoneType()) {
       LazyRandomTypeCollection &ids = m_index->ipi().typeCollection();
diff --git a/llvm/include/llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h b/llvm/include/llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h
index 5b23ac9f862a0..da18339b8662b 100644
--- a/llvm/include/llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h
+++ b/llvm/include/llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h
@@ -70,7 +70,7 @@ class LLVM_ABI LazyRandomTypeCollection : public TypeCollection {
   uint32_t getOffsetOfType(TypeIndex Index);
 
   std::optional<CVType> tryGetType(TypeIndex Index);
-
+  llvm::Expected<CVType> getTypeOrError(TypeIndex Index);
   CVType getType(TypeIndex Index) override;
   StringRef getTypeName(TypeIndex Index) override;
   bool contains(TypeIndex Index) override;
diff --git a/llvm/lib/DebugInfo/CodeView/LazyRandomTypeCollection.cpp b/llvm/lib/DebugInfo/CodeView/LazyRandomTypeCollection.cpp
index 23ab5344df1ed..0b36c5085c086 100644
--- a/llvm/lib/DebugInfo/CodeView/LazyRandomTypeCollection.cpp
+++ b/llvm/lib/DebugInfo/CodeView/LazyRandomTypeCollection.cpp
@@ -93,20 +93,25 @@ CVType LazyRandomTypeCollection::getType(TypeIndex Index) {
   return Records[Index.toArrayIndex()].Type;
 }
 
-std::optional<CVType> LazyRandomTypeCollection::tryGetType(TypeIndex Index) {
+llvm::Expected<CVType>
+LazyRandomTypeCollection::getTypeOrError(TypeIndex Index) {
   if (Index.isSimple())
-    return std::nullopt;
+    return llvm::createStringError("Type index too low (%d)", Index.getIndex());
 
   if (auto EC = ensureTypeExists(Index)) {
-    consumeError(std::move(EC));
-    return std::nullopt;
+    return EC;
   }
 
   if (!contains(Index))
-    return std::nullopt;
+    return llvm::createStringError("Type index too high (%d)",
+                                   Index.getIndex());
   return Records[Index.toArrayIndex()].Type;
 }
 
+std::optional<CVType> LazyRandomTypeCollection::tryGetType(TypeIndex Index) {
+  return llvm::expectedToOptional(getTypeOrError(Index));
+}
+
 StringRef LazyRandomTypeCollection::getTypeName(TypeIndex Index) {
   if (Index.isNoneType() || Index.isSimple())
     return TypeIndex::simpleTypeName(Index);