Vendor import of stripped lldb trunk r375505, the last commit before thevendor/lldb/lldb-trunk-r375505vendor/lldb

upstream Subversion repository was made read-only, and the LLVM project
migrated to GitHub:

https://llvm.org/svn/llvm-project/lldb/trunk@375505

8 files changed, 135 insertions, 174 deletions

diff --git a/source/Plugins/SymbolFile/NativePDB/CompileUnitIndex.cpp b/source/Plugins/SymbolFile/NativePDB/CompileUnitIndex.cpp
index 1838204e4ca6..830d78f81679 100644
--- a/source/Plugins/SymbolFile/NativePDB/CompileUnitIndex.cpp
+++ b/source/Plugins/SymbolFile/NativePDB/CompileUnitIndex.cpp
@@ -130,7 +130,7 @@ CompilandIndexItem &CompileUnitIndex::GetOrCreateCompiland(uint16_t modi) {
 
   if (!stream_data) {
     llvm::pdb::ModuleDebugStreamRef debug_stream(descriptor, nullptr);
-    cci = llvm::make_unique<CompilandIndexItem>(PdbCompilandId{ modi }, debug_stream, std::move(descriptor));
+    cci = std::make_unique<CompilandIndexItem>(PdbCompilandId{ modi }, debug_stream, std::move(descriptor));
     return *cci;
   }
 
@@ -139,7 +139,7 @@ CompilandIndexItem &CompileUnitIndex::GetOrCreateCompiland(uint16_t modi) {
 
   cantFail(debug_stream.reload());
 
-  cci = llvm::make_unique<CompilandIndexItem>(
+  cci = std::make_unique<CompilandIndexItem>(
       PdbCompilandId{modi}, std::move(debug_stream), std::move(descriptor));
   ParseExtendedInfo(m_index, *cci);
 
diff --git a/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp b/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
index 3d8bfb058721..6aaff06cc134 100644
--- a/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
+++ b/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
@@ -122,7 +122,7 @@ static DWARFExpression MakeLocationExpressionInternal(lldb::ModuleSP module,
   DataBufferSP buffer =
       std::make_shared<DataBufferHeap>(stream.GetData(), stream.GetSize());
   DataExtractor extractor(buffer, byte_order, address_size, byte_size);
-  DWARFExpression result(module, extractor, nullptr, 0, buffer->GetByteSize());
+  DWARFExpression result(module, extractor, nullptr);
   result.SetRegisterKind(register_kind);
 
   return result;
@@ -247,6 +247,6 @@ DWARFExpression lldb_private::npdb::MakeConstantLocationExpression(
               .take_front(size);
   buffer->CopyData(bytes.data(), size);
   DataExtractor extractor(buffer, lldb::eByteOrderLittle, address_size);
-  DWARFExpression result(nullptr, extractor, nullptr, 0, size);
+  DWARFExpression result(nullptr, extractor, nullptr);
   return result;
 }
diff --git a/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp b/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp
index 4991be8e70ce..986b0b785d87 100644
--- a/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp
+++ b/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp
@@ -121,13 +121,6 @@ AnyScopesHaveTemplateParams(llvm::ArrayRef<llvm::ms_demangle::Node *> scopes) {
   return false;
 }
 
-static ClangASTContext &GetClangASTContext(ObjectFile &obj) {
-  TypeSystem *ts =
-      obj.GetModule()->GetTypeSystemForLanguage(lldb::eLanguageTypeC_plus_plus);
-  lldbassert(ts);
-  return static_cast<ClangASTContext &>(*ts);
-}
-
 static llvm::Optional<clang::CallingConv>
 TranslateCallingConvention(llvm::codeview::CallingConvention conv) {
   using CC = llvm::codeview::CallingConvention;
@@ -209,8 +202,8 @@ static bool IsAnonymousNamespaceName(llvm::StringRef name) {
   return name == "`anonymous namespace'" || name == "`anonymous-namespace'";
 }
 
-PdbAstBuilder::PdbAstBuilder(ObjectFile &obj, PdbIndex &index)
-    : m_index(index), m_clang(GetClangASTContext(obj)) {
+PdbAstBuilder::PdbAstBuilder(ObjectFile &obj, PdbIndex &index, ClangASTContext &clang)
+    : m_index(index), m_clang(clang) {
   BuildParentMap();
 }
 
@@ -465,9 +458,9 @@ clang::Decl *PdbAstBuilder::GetOrCreateSymbolForId(PdbCompilandSymId id) {
   }
 }
 
-clang::Decl *PdbAstBuilder::GetOrCreateDeclForUid(PdbSymUid uid) {
+llvm::Optional<CompilerDecl> PdbAstBuilder::GetOrCreateDeclForUid(PdbSymUid uid) {
   if (clang::Decl *result = TryGetDecl(uid))
-    return result;
+    return ToCompilerDecl(*result);
 
   clang::Decl *result = nullptr;
   switch (uid.kind()) {
@@ -480,13 +473,13 @@ clang::Decl *PdbAstBuilder::GetOrCreateDeclForUid(PdbSymUid uid) {
       result = tag;
       break;
     }
-    return nullptr;
+    return llvm::None;
   }
   default:
-    return nullptr;
+    return llvm::None;
   }
   m_uid_to_decl[toOpaqueUid(uid)] = result;
-  return result;
+  return ToCompilerDecl(*result);
 }
 
 clang::DeclContext *PdbAstBuilder::GetOrCreateDeclContextForUid(PdbSymUid uid) {
@@ -494,8 +487,10 @@ clang::DeclContext *PdbAstBuilder::GetOrCreateDeclContextForUid(PdbSymUid uid) {
     if (uid.asCompilandSym().offset == 0)
       return FromCompilerDeclContext(GetTranslationUnitDecl());
   }
-
-  clang::Decl *decl = GetOrCreateDeclForUid(uid);
+  auto option = GetOrCreateDeclForUid(uid);
+  if (!option)
+    return nullptr;
+  clang::Decl *decl = FromCompilerDecl(option.getValue());
   if (!decl)
     return nullptr;
 
@@ -1089,7 +1084,7 @@ void PdbAstBuilder::CreateFunctionParameters(PdbCompilandSymId func_id,
     CompilerType param_type_ct(&m_clang, qt.getAsOpaquePtr());
     clang::ParmVarDecl *param = m_clang.CreateParameterDeclaration(
         &function_decl, param_name.str().c_str(), param_type_ct,
-        clang::SC_None);
+        clang::SC_None, true);
     lldbassert(m_uid_to_decl.count(toOpaqueUid(param_uid)) == 0);
 
     m_uid_to_decl[toOpaqueUid(param_uid)] = param;
diff --git a/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.h b/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.h
index 67d024741e0d..a4242e90810d 100644
--- a/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.h
+++ b/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.h
@@ -51,11 +51,12 @@ struct DeclStatus {
 class PdbAstBuilder {
 public:
   // Constructors and Destructors
-  PdbAstBuilder(ObjectFile &obj, PdbIndex &index);
+  PdbAstBuilder(ObjectFile &obj, PdbIndex &index, ClangASTContext &clang);
 
   lldb_private::CompilerDeclContext GetTranslationUnitDecl();
 
-  clang::Decl *GetOrCreateDeclForUid(PdbSymUid uid);
+  llvm::Optional<lldb_private::CompilerDecl>
+  GetOrCreateDeclForUid(PdbSymUid uid);
   clang::DeclContext *GetOrCreateDeclContextForUid(PdbSymUid uid);
   clang::DeclContext *GetParentDeclContext(PdbSymUid uid);
 
@@ -76,7 +77,7 @@ public:
   CompilerDecl ToCompilerDecl(clang::Decl &decl);
   CompilerType ToCompilerType(clang::QualType qt);
   CompilerDeclContext ToCompilerDeclContext(clang::DeclContext &context);
-  clang::Decl * FromCompilerDecl(CompilerDecl decl);
+  clang::Decl *FromCompilerDecl(CompilerDecl decl);
   clang::DeclContext *FromCompilerDeclContext(CompilerDeclContext context);
 
   ClangASTContext &clang() { return m_clang; }
diff --git a/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp b/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp
index 79dd010ff311..a7bc23519710 100644
--- a/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp
+++ b/source/Plugins/SymbolFile/NativePDB/PdbFPOProgramToDWARFExpression.cpp
@@ -51,54 +51,23 @@ static uint32_t ResolveLLDBRegisterNum(llvm::StringRef reg_name, llvm::Triple::A
   return npdb::GetLLDBRegisterNumber(arch_type, reg_id);
 }
 
-static bool ParseFPOSingleAssignmentProgram(llvm::StringRef program,
-                                            llvm::BumpPtrAllocator &alloc,
-                                            llvm::StringRef &register_name,
-                                            Node *&ast) {
-  // lvalue of assignment is always first token
-  // rvalue program goes next
-  std::tie(register_name, program) = getToken(program);
-  if (register_name.empty())
-    return false;
-
-  ast = Parse(program, alloc);
-  return ast != nullptr;
-}
-
-static Node *ParseFPOProgram(llvm::StringRef program,
+static Node *ResolveFPOProgram(llvm::StringRef program,
                              llvm::StringRef register_name,
                              llvm::Triple::ArchType arch_type,
                              llvm::BumpPtrAllocator &alloc) {
-  llvm::DenseMap<llvm::StringRef, Node *> dependent_programs;
-
-  size_t cur = 0;
-  while (true) {
-    size_t assign_index = program.find('=', cur);
-    if (assign_index == llvm::StringRef::npos) {
-      llvm::StringRef tail = program.slice(cur, llvm::StringRef::npos);
-      if (!tail.trim().empty()) {
-        // missing assign operator
-        return nullptr;
-      }
-      break;
-    }
-    llvm::StringRef assignment_program = program.slice(cur, assign_index);
-
-    llvm::StringRef lvalue_name;
-    Node *rvalue_ast = nullptr;
-    if (!ParseFPOSingleAssignmentProgram(assignment_program, alloc, lvalue_name,
-                                         rvalue_ast)) {
-      return nullptr;
-    }
-
-    lldbassert(rvalue_ast);
+  std::vector<std::pair<llvm::StringRef, Node *>> parsed =
+      postfix::ParseFPOProgram(program, alloc);
 
+  for (auto it = parsed.begin(), end = parsed.end(); it != end; ++it) {
     // Emplace valid dependent subtrees to make target assignment independent
     // from predecessors. Resolve all other SymbolNodes as registers.
     bool success =
-        ResolveSymbols(rvalue_ast, [&](SymbolNode &symbol) -> Node * {
-          if (Node *node = dependent_programs.lookup(symbol.GetName()))
-            return node;
+        ResolveSymbols(it->second, [&](SymbolNode &symbol) -> Node * {
+          for (const auto &pair : llvm::make_range(parsed.begin(), it)) {
+            if (pair.first == symbol.GetName())
+              return pair.second;
+          }
+
           uint32_t reg_num =
               ResolveLLDBRegisterNum(symbol.GetName().drop_front(1), arch_type);
 
@@ -110,13 +79,10 @@ static Node *ParseFPOProgram(llvm::StringRef program,
     if (!success)
       return nullptr;
 
-    if (lvalue_name == register_name) {
+    if (it->first == register_name) {
       // found target assignment program - no need to parse further
-      return rvalue_ast;
+      return it->second;
     }
-
-    dependent_programs[lvalue_name] = rvalue_ast;
-    cur = assign_index + 1;
   }
 
   return nullptr;
@@ -127,7 +93,7 @@ bool lldb_private::npdb::TranslateFPOProgramToDWARFExpression(
     llvm::Triple::ArchType arch_type, Stream &stream) {
   llvm::BumpPtrAllocator node_alloc;
   Node *target_program =
-      ParseFPOProgram(program, register_name, arch_type, node_alloc);
+      ResolveFPOProgram(program, register_name, arch_type, node_alloc);
   if (target_program == nullptr) {
     return false;
   }
diff --git a/source/Plugins/SymbolFile/NativePDB/PdbUtil.cpp b/source/Plugins/SymbolFile/NativePDB/PdbUtil.cpp
index 1f5c97da81cf..fc047e25a2f4 100644
--- a/source/Plugins/SymbolFile/NativePDB/PdbUtil.cpp
+++ b/source/Plugins/SymbolFile/NativePDB/PdbUtil.cpp
@@ -641,14 +641,14 @@ VariableInfo lldb_private::npdb::GetVariableLocationInfo(
         llvm::StringRef program;
         if (GetFrameDataProgram(index, ranges, program)) {
           result.location =
-              MakeVFrameRelLocationExpression(program, loc.Offset, module);
+              MakeVFrameRelLocationExpression(program, loc.Hdr.Offset, module);
           result.ranges = std::move(ranges);
         } else {
           // invalid variable
         }
       } else {
         result.location =
-            MakeRegRelLocationExpression(base_reg, loc.Offset, module);
+            MakeRegRelLocationExpression(base_reg, loc.Hdr.Offset, module);
         result.ranges = std::move(ranges);
       }
     } else if (loc_specifier_cvs.kind() == S_DEFRANGE_REGISTER_REL) {
diff --git a/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
index e27d4699ae2f..33b8da3b543b 100644
--- a/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -20,7 +20,6 @@
 #include "lldb/Core/StreamBuffer.h"
 #include "lldb/Core/StreamFile.h"
 #include "lldb/Symbol/ClangASTContext.h"
-#include "lldb/Symbol/ClangASTImporter.h"
 #include "lldb/Symbol/ClangExternalASTSourceCommon.h"
 #include "lldb/Symbol/ClangUtil.h"
 #include "lldb/Symbol/CompileUnit.h"
@@ -30,6 +29,7 @@
 #include "lldb/Symbol/SymbolVendor.h"
 #include "lldb/Symbol/Variable.h"
 #include "lldb/Symbol/VariableList.h"
+#include "lldb/Utility/Log.h"
 
 #include "llvm/DebugInfo/CodeView/CVRecord.h"
 #include "llvm/DebugInfo/CodeView/CVTypeVisitor.h"
@@ -90,10 +90,10 @@ static std::unique_ptr<PDBFile> loadPDBFile(std::string PdbPath,
   std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(*ErrorOrBuffer);
 
   llvm::StringRef Path = Buffer->getBufferIdentifier();
-  auto Stream = llvm::make_unique<llvm::MemoryBufferByteStream>(
+  auto Stream = std::make_unique<llvm::MemoryBufferByteStream>(
       std::move(Buffer), llvm::support::little);
 
-  auto File = llvm::make_unique<PDBFile>(Path, std::move(Stream), Allocator);
+  auto File = std::make_unique<PDBFile>(Path, std::move(Stream), Allocator);
   if (auto EC = File->parseFileHeaders()) {
     llvm::consumeError(std::move(EC));
     return nullptr;
@@ -119,6 +119,8 @@ loadMatchingPDBFile(std::string exe_path, llvm::BumpPtrAllocator &allocator) {
   }
   OwningBinary<Binary> binary = std::move(*expected_binary);
 
+  // TODO: Avoid opening the PE/COFF binary twice by reading this information
+  // directly from the lldb_private::ObjectFile.
   auto *obj = llvm::dyn_cast<llvm::object::COFFObjectFile>(binary.getBinary());
   if (!obj)
     return nullptr;
@@ -264,27 +266,27 @@ const char *SymbolFileNativePDB::GetPluginDescriptionStatic() {
   return "Microsoft PDB debug symbol cross-platform file reader.";
 }
 
-SymbolFile *SymbolFileNativePDB::CreateInstance(ObjectFile *obj_file) {
-  return new SymbolFileNativePDB(obj_file);
+SymbolFile *SymbolFileNativePDB::CreateInstance(ObjectFileSP objfile_sp) {
+  return new SymbolFileNativePDB(std::move(objfile_sp));
 }
 
-SymbolFileNativePDB::SymbolFileNativePDB(ObjectFile *object_file)
-    : SymbolFile(object_file) {}
+SymbolFileNativePDB::SymbolFileNativePDB(ObjectFileSP objfile_sp)
+    : SymbolFile(std::move(objfile_sp)) {}
 
 SymbolFileNativePDB::~SymbolFileNativePDB() {}
 
 uint32_t SymbolFileNativePDB::CalculateAbilities() {
   uint32_t abilities = 0;
-  if (!m_obj_file)
+  if (!m_objfile_sp)
     return 0;
 
   if (!m_index) {
     // Lazily load and match the PDB file, but only do this once.
     std::unique_ptr<PDBFile> file_up =
-        loadMatchingPDBFile(m_obj_file->GetFileSpec().GetPath(), m_allocator);
+        loadMatchingPDBFile(m_objfile_sp->GetFileSpec().GetPath(), m_allocator);
 
     if (!file_up) {
-      auto module_sp = m_obj_file->GetModule();
+      auto module_sp = m_objfile_sp->GetModule();
       if (!module_sp)
         return 0;
       // See if any symbol file is specified through `--symfile` option.
@@ -317,19 +319,24 @@ uint32_t SymbolFileNativePDB::CalculateAbilities() {
 }
 
 void SymbolFileNativePDB::InitializeObject() {
-  m_obj_load_address = m_obj_file->GetBaseAddress().GetFileAddress();
+  m_obj_load_address = m_objfile_sp->GetBaseAddress().GetFileAddress();
   m_index->SetLoadAddress(m_obj_load_address);
   m_index->ParseSectionContribs();
 
-  TypeSystem *ts = m_obj_file->GetModule()->GetTypeSystemForLanguage(
+  auto ts_or_err = m_objfile_sp->GetModule()->GetTypeSystemForLanguage(
       lldb::eLanguageTypeC_plus_plus);
-  if (ts)
-    ts->SetSymbolFile(this);
-
-  m_ast = llvm::make_unique<PdbAstBuilder>(*m_obj_file, *m_index);
+  if (auto err = ts_or_err.takeError()) {
+    LLDB_LOG_ERROR(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_SYMBOLS),
+                   std::move(err), "Failed to initialize");
+  } else {
+    ts_or_err->SetSymbolFile(this);
+    auto *clang = llvm::cast_or_null<ClangASTContext>(&ts_or_err.get());
+    lldbassert(clang);
+    m_ast = std::make_unique<PdbAstBuilder>(*m_objfile_sp, *m_index, *clang);
+  }
 }
 
-uint32_t SymbolFileNativePDB::GetNumCompileUnits() {
+uint32_t SymbolFileNativePDB::CalculateNumCompileUnits() {
   const DbiModuleList &modules = m_index->dbi().modules();
   uint32_t count = modules.getModuleCount();
   if (count == 0)
@@ -430,11 +437,10 @@ SymbolFileNativePDB::CreateCompileUnit(const CompilandIndexItem &cci) {
   FileSpec fs(source_file_name);
 
   CompUnitSP cu_sp =
-      std::make_shared<CompileUnit>(m_obj_file->GetModule(), nullptr, fs,
+      std::make_shared<CompileUnit>(m_objfile_sp->GetModule(), nullptr, fs,
                                     toOpaqueUid(cci.m_id), lang, optimized);
 
-  m_obj_file->GetModule()->GetSymbolVendor()->SetCompileUnitAtIndex(
-      cci.m_id.modi, cu_sp);
+  SetCompileUnitAtIndex(cci.m_id.modi, cu_sp);
   return cu_sp;
 }
 
@@ -730,7 +736,7 @@ TypeSP SymbolFileNativePDB::GetOrCreateType(PdbTypeSymId type_id) {
 
   TypeSP type = CreateAndCacheType(type_id);
   if (type)
-    m_obj_file->GetModule()->GetTypeList()->Insert(type);
+    GetTypeList().Insert(type);
   return type;
 }
 
@@ -900,6 +906,7 @@ lldb::CompUnitSP SymbolFileNativePDB::ParseCompileUnitAtIndex(uint32_t index) {
 }
 
 lldb::LanguageType SymbolFileNativePDB::ParseLanguage(CompileUnit &comp_unit) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   PdbSymUid uid(comp_unit.GetID());
   lldbassert(uid.kind() == PdbSymUidKind::Compiland);
 
@@ -915,6 +922,7 @@ lldb::LanguageType SymbolFileNativePDB::ParseLanguage(CompileUnit &comp_unit) {
 void SymbolFileNativePDB::AddSymbols(Symtab &symtab) { return; }
 
 size_t SymbolFileNativePDB::ParseFunctions(CompileUnit &comp_unit) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   PdbSymUid uid{comp_unit.GetID()};
   lldbassert(uid.kind() == PdbSymUidKind::Compiland);
   uint16_t modi = uid.asCompiland().modi;
@@ -948,6 +956,7 @@ static bool NeedsResolvedCompileUnit(uint32_t resolve_scope) {
 
 uint32_t SymbolFileNativePDB::ResolveSymbolContext(
     const Address &addr, SymbolContextItem resolve_scope, SymbolContext &sc) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   uint32_t resolved_flags = 0;
   lldb::addr_t file_addr = addr.GetFileAddress();
 
@@ -1052,12 +1061,13 @@ bool SymbolFileNativePDB::ParseLineTable(CompileUnit &comp_unit) {
   // all at once, even if all it really needs is line info for a specific
   // function.  In the future it would be nice if it could set the sc.m_function
   // member, and we could only get the line info for the function in question.
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   PdbSymUid cu_id(comp_unit.GetID());
   lldbassert(cu_id.kind() == PdbSymUidKind::Compiland);
   CompilandIndexItem *cci =
       m_index->compilands().GetCompiland(cu_id.asCompiland().modi);
   lldbassert(cci);
-  auto line_table = llvm::make_unique<LineTable>(&comp_unit);
+  auto line_table = std::make_unique<LineTable>(&comp_unit);
 
   // This is basically a copy of the .debug$S subsections from all original COFF
   // object files merged together with address relocations applied.  We are
@@ -1130,6 +1140,7 @@ bool SymbolFileNativePDB::ParseDebugMacros(CompileUnit &comp_unit) {
 
 bool SymbolFileNativePDB::ParseSupportFiles(CompileUnit &comp_unit,
                                             FileSpecList &support_files) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   PdbSymUid cu_id(comp_unit.GetID());
   lldbassert(cu_id.kind() == PdbSymUidKind::Compiland);
   CompilandIndexItem *cci =
@@ -1160,6 +1171,7 @@ bool SymbolFileNativePDB::ParseImportedModules(
 }
 
 size_t SymbolFileNativePDB::ParseBlocksRecursive(Function &func) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   GetOrCreateBlock(PdbSymUid(func.GetID()).asCompilandSym());
   // FIXME: Parse child blocks
   return 1;
@@ -1167,9 +1179,10 @@ size_t SymbolFileNativePDB::ParseBlocksRecursive(Function &func) {
 
 void SymbolFileNativePDB::DumpClangAST(Stream &s) { m_ast->Dump(s); }
 
-uint32_t SymbolFileNativePDB::FindGlobalVariables(
+void SymbolFileNativePDB::FindGlobalVariables(
     ConstString name, const CompilerDeclContext *parent_decl_ctx,
     uint32_t max_matches, VariableList &variables) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   using SymbolAndOffset = std::pair<uint32_t, llvm::codeview::CVSymbol>;
 
   std::vector<SymbolAndOffset> results = m_index->globals().findRecordsByName(
@@ -1191,16 +1204,16 @@ uint32_t SymbolFileNativePDB::FindGlobalVariables(
       continue;
     }
   }
-  return variables.GetSize();
 }
 
-uint32_t SymbolFileNativePDB::FindFunctions(
+void SymbolFileNativePDB::FindFunctions(
     ConstString name, const CompilerDeclContext *parent_decl_ctx,
-    FunctionNameType name_type_mask, bool include_inlines, bool append,
+    FunctionNameType name_type_mask, bool include_inlines,
     SymbolContextList &sc_list) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   // For now we only support lookup by method name.
   if (!(name_type_mask & eFunctionNameTypeMethod))
-    return 0;
+    return;
 
   using SymbolAndOffset = std::pair<uint32_t, llvm::codeview::CVSymbol>;
 
@@ -1225,45 +1238,34 @@ uint32_t SymbolFileNativePDB::FindFunctions(
 
     sc_list.Append(sc);
   }
-
-  return sc_list.GetSize();
 }
 
-uint32_t SymbolFileNativePDB::FindFunctions(const RegularExpression &regex,
-                                            bool include_inlines, bool append,
-                                            SymbolContextList &sc_list) {
-  return 0;
-}
+void SymbolFileNativePDB::FindFunctions(const RegularExpression &regex,
+                                        bool include_inlines,
+                                        SymbolContextList &sc_list) {}
 
-uint32_t SymbolFileNativePDB::FindTypes(
+void SymbolFileNativePDB::FindTypes(
     ConstString name, const CompilerDeclContext *parent_decl_ctx,
-    bool append, uint32_t max_matches,
-    llvm::DenseSet<SymbolFile *> &searched_symbol_files, TypeMap &types) {
-  if (!append)
-    types.Clear();
+    uint32_t max_matches, llvm::DenseSet<SymbolFile *> &searched_symbol_files,
+    TypeMap &types) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   if (!name)
-    return 0;
+    return;
 
   searched_symbol_files.clear();
   searched_symbol_files.insert(this);
 
   // There is an assumption 'name' is not a regex
-  size_t match_count = FindTypesByName(name.GetStringRef(), max_matches, types);
-
-  return match_count;
+  FindTypesByName(name.GetStringRef(), max_matches, types);
 }
 
-size_t
-SymbolFileNativePDB::FindTypes(const std::vector<CompilerContext> &context,
-                               bool append, TypeMap &types) {
-  return 0;
-}
+void SymbolFileNativePDB::FindTypes(llvm::ArrayRef<CompilerContext> pattern,
+                                    LanguageSet languages, TypeMap &types) {}
 
-size_t SymbolFileNativePDB::FindTypesByName(llvm::StringRef name,
-                                            uint32_t max_matches,
-                                            TypeMap &types) {
+void SymbolFileNativePDB::FindTypesByName(llvm::StringRef name,
+                                          uint32_t max_matches,
+                                          TypeMap &types) {
 
-  size_t match_count = 0;
   std::vector<TypeIndex> matches = m_index->tpi().findRecordsByName(name);
   if (max_matches > 0 && max_matches < matches.size())
     matches.resize(max_matches);
@@ -1274,17 +1276,16 @@ size_t SymbolFileNativePDB::FindTypesByName(llvm::StringRef name,
       continue;
 
     types.Insert(type);
-    ++match_count;
   }
-  return match_count;
 }
 
 size_t SymbolFileNativePDB::ParseTypes(CompileUnit &comp_unit) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   // Only do the full type scan the first time.
   if (m_done_full_type_scan)
     return 0;
 
-  size_t old_count = m_obj_file->GetModule()->GetTypeList()->GetSize();
+  const size_t old_count = GetTypeList().GetSize();
   LazyRandomTypeCollection &types = m_index->tpi().typeCollection();
 
   // First process the entire TPI stream.
@@ -1314,7 +1315,7 @@ size_t SymbolFileNativePDB::ParseTypes(CompileUnit &comp_unit) {
       GetOrCreateTypedef(global);
   }
 
-  size_t new_count = m_obj_file->GetModule()->GetTypeList()->GetSize();
+  const size_t new_count = GetTypeList().GetSize();
 
   m_done_full_type_scan = true;
 
@@ -1476,6 +1477,7 @@ size_t SymbolFileNativePDB::ParseVariablesForBlock(PdbCompilandSymId block_id) {
 }
 
 size_t SymbolFileNativePDB::ParseVariablesForContext(const SymbolContext &sc) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   lldbassert(sc.function || sc.comp_unit);
 
   VariableListSP variables;
@@ -1506,9 +1508,10 @@ size_t SymbolFileNativePDB::ParseVariablesForContext(const SymbolContext &sc) {
 }
 
 CompilerDecl SymbolFileNativePDB::GetDeclForUID(lldb::user_id_t uid) {
-  clang::Decl *decl = m_ast->GetOrCreateDeclForUid(PdbSymUid(uid));
-
-  return m_ast->ToCompilerDecl(*decl);
+  if (auto decl = m_ast->GetOrCreateDeclForUid(uid))
+    return decl.getValue();
+  else
+    return CompilerDecl();
 }
 
 CompilerDeclContext
@@ -1528,6 +1531,7 @@ SymbolFileNativePDB::GetDeclContextContainingUID(lldb::user_id_t uid) {
 }
 
 Type *SymbolFileNativePDB::ResolveTypeUID(lldb::user_id_t type_uid) {
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
   auto iter = m_types.find(type_uid);
   // lldb should not be passing us non-sensical type uids.  the only way it
   // could have a type uid in the first place is if we handed it out, in which
@@ -1561,11 +1565,9 @@ bool SymbolFileNativePDB::CompleteType(CompilerType &compiler_type) {
   return m_ast->CompleteType(qt);
 }
 
-size_t SymbolFileNativePDB::GetTypes(lldb_private::SymbolContextScope *sc_scope,
-                                     TypeClass type_mask,
-                                     lldb_private::TypeList &type_list) {
-  return 0;
-}
+void SymbolFileNativePDB::GetTypes(lldb_private::SymbolContextScope *sc_scope,
+                                   TypeClass type_mask,
+                                   lldb_private::TypeList &type_list) {}
 
 CompilerDeclContext
 SymbolFileNativePDB::FindNamespace(ConstString name,
@@ -1573,13 +1575,14 @@ SymbolFileNativePDB::FindNamespace(ConstString name,
   return {};
 }
 
-TypeSystem *
+llvm::Expected<TypeSystem &>
 SymbolFileNativePDB::GetTypeSystemForLanguage(lldb::LanguageType language) {
-  auto type_system =
-      m_obj_file->GetModule()->GetTypeSystemForLanguage(language);
-  if (type_system)
-    type_system->SetSymbolFile(this);
-  return type_system;
+  auto type_system_or_err =
+      m_objfile_sp->GetModule()->GetTypeSystemForLanguage(language);
+  if (type_system_or_err) {
+    type_system_or_err->SetSymbolFile(this);
+  }
+  return type_system_or_err;
 }
 
 ConstString SymbolFileNativePDB::GetPluginName() {
diff --git a/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h b/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
index 20daff219a0a..ca7de0e7d1ed 100644
--- a/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
+++ b/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
@@ -9,7 +9,6 @@
 #ifndef LLDB_PLUGINS_SYMBOLFILE_NATIVEPDB_SYMBOLFILENATIVEPDB_H
 #define LLDB_PLUGINS_SYMBOLFILE_NATIVEPDB_SYMBOLFILENATIVEPDB_H
 
-#include "lldb/Symbol/ClangASTImporter.h"
 #include "lldb/Symbol/SymbolFile.h"
 
 #include "llvm/ADT/DenseMap.h"
@@ -35,7 +34,6 @@ struct UnionRecord;
 } // namespace llvm
 
 namespace lldb_private {
-class ClangASTImporter;
 
 namespace npdb {
 class PdbAstBuilder;
@@ -55,10 +53,10 @@ public:
 
   static const char *GetPluginDescriptionStatic();
 
-  static SymbolFile *CreateInstance(ObjectFile *obj_file);
+  static SymbolFile *CreateInstance(lldb::ObjectFileSP objfile_sp);
 
   // Constructors and Destructors
-  SymbolFileNativePDB(ObjectFile *ofile);
+  SymbolFileNativePDB(lldb::ObjectFileSP objfile_sp);
 
   ~SymbolFileNativePDB() override;
 
@@ -68,13 +66,9 @@ public:
 
   // Compile Unit function calls
 
-  uint32_t GetNumCompileUnits() override;
-
   void
   ParseDeclsForContext(lldb_private::CompilerDeclContext decl_ctx) override;
 
-  lldb::CompUnitSP ParseCompileUnitAtIndex(uint32_t index) override;
-
   lldb::LanguageType
   ParseLanguage(lldb_private::CompileUnit &comp_unit) override;
 
@@ -94,10 +88,10 @@ public:
 
   size_t ParseBlocksRecursive(Function &func) override;
 
-  uint32_t FindGlobalVariables(ConstString name,
-                               const CompilerDeclContext *parent_decl_ctx,
-                               uint32_t max_matches,
-                               VariableList &variables) override;
+  void FindGlobalVariables(ConstString name,
+                           const CompilerDeclContext *parent_decl_ctx,
+                           uint32_t max_matches,
+                           VariableList &variables) override;
 
   size_t ParseVariablesForContext(const SymbolContext &sc) override;
 
@@ -120,28 +114,27 @@ public:
                                 lldb::SymbolContextItem resolve_scope,
                                 SymbolContextList &sc_list) override;
 
-  size_t GetTypes(SymbolContextScope *sc_scope, lldb::TypeClass type_mask,
-                  TypeList &type_list) override;
+  void GetTypes(SymbolContextScope *sc_scope, lldb::TypeClass type_mask,
+                TypeList &type_list) override;
 
-  uint32_t FindFunctions(ConstString name,
-                         const CompilerDeclContext *parent_decl_ctx,
-                         lldb::FunctionNameType name_type_mask,
-                         bool include_inlines, bool append,
-                         SymbolContextList &sc_list) override;
+  void FindFunctions(ConstString name,
+                     const CompilerDeclContext *parent_decl_ctx,
+                     lldb::FunctionNameType name_type_mask,
+                     bool include_inlines, SymbolContextList &sc_list) override;
 
-  uint32_t FindFunctions(const RegularExpression &regex, bool include_inlines,
-                         bool append, SymbolContextList &sc_list) override;
+  void FindFunctions(const RegularExpression &regex, bool include_inlines,
+                     SymbolContextList &sc_list) override;
 
-  uint32_t FindTypes(ConstString name,
-                     const CompilerDeclContext *parent_decl_ctx, bool append,
-                     uint32_t max_matches,
-                     llvm::DenseSet<SymbolFile *> &searched_symbol_files,
-                     TypeMap &types) override;
+  void FindTypes(ConstString name, const CompilerDeclContext *parent_decl_ctx,
+                 uint32_t max_matches,
+                 llvm::DenseSet<SymbolFile *> &searched_symbol_files,
+                 TypeMap &types) override;
 
-  size_t FindTypes(const std::vector<CompilerContext> &context, bool append,
-                   TypeMap &types) override;
+  void FindTypes(llvm::ArrayRef<CompilerContext> pattern, LanguageSet languages,
+                 TypeMap &types) override;
 
-  TypeSystem *GetTypeSystemForLanguage(lldb::LanguageType language) override;
+  llvm::Expected<TypeSystem &>
+  GetTypeSystemForLanguage(lldb::LanguageType language) override;
 
   CompilerDeclContext
   FindNamespace(ConstString name,
@@ -157,9 +150,12 @@ public:
   void DumpClangAST(Stream &s) override;
 
 private:
+  uint32_t CalculateNumCompileUnits() override;
+
+  lldb::CompUnitSP ParseCompileUnitAtIndex(uint32_t index) override;
 
-  size_t FindTypesByName(llvm::StringRef name, uint32_t max_matches,
-                         TypeMap &types);
+  void FindTypesByName(llvm::StringRef name, uint32_t max_matches,
+                       TypeMap &types);
 
   lldb::TypeSP CreateModifierType(PdbTypeSymId type_id,
                                   const llvm::codeview::ModifierRecord &mr,