[lldb][NFCI] Module constructor should take ConstString by value

ConstStrings are super cheap to copy around. It is often more expensive
to pass a pointer and potentially dereference it than just to always copy it.

Differential Revision: https://reviews.llvm.org/D158043

Author: bulbazord

lldb/include/lldb/Core/Module.h

@@ -124,8 +124,7 @@ class Module : public std::enable_shared_from_this<Module>,
   ///     multiple architectures).
   Module(
       const FileSpec &file_spec, const ArchSpec &arch,
-      const ConstString *object_name = nullptr,
-      lldb::offset_t object_offset = 0,
+      ConstString object_name = ConstString(), lldb::offset_t object_offset = 0,
       const llvm::sys::TimePoint<> &object_mod_time = llvm::sys::TimePoint<>());
 
   Module(const ModuleSpec &module_spec);

lldb/source/Core/Module.cpp

@@ -233,22 +233,19 @@ Module::Module(const ModuleSpec &module_spec)
 }
 
 Module::Module(const FileSpec &file_spec, const ArchSpec &arch,
-               const ConstString *object_name, lldb::offset_t object_offset,
+               ConstString object_name, lldb::offset_t object_offset,
                const llvm::sys::TimePoint<> &object_mod_time)
     : m_mod_time(FileSystem::Instance().GetModificationTime(file_spec)),
-      m_arch(arch), m_file(file_spec), m_object_offset(object_offset),
-      m_object_mod_time(object_mod_time), m_file_has_changed(false),
-      m_first_file_changed_log(false) {
+      m_arch(arch), m_file(file_spec), m_object_name(object_name),
+      m_object_offset(object_offset), m_object_mod_time(object_mod_time),
+      m_file_has_changed(false), m_first_file_changed_log(false) {
   // Scope for locker below...
   {
     std::lock_guard<std::recursive_mutex> guard(
         GetAllocationModuleCollectionMutex());
     GetModuleCollection().push_back(this);
   }
 
-  if (object_name)
-    m_object_name = *object_name;
-
   Log *log(GetLog(LLDBLog::Object | LLDBLog::Modules));
   if (log != nullptr)
     LLDB_LOGF(log, "%p Module::Module((%s) '%s%s%s%s')",

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp

@@ -170,7 +170,7 @@ class DebugMapModule : public Module {
 public:
   DebugMapModule(const ModuleSP &exe_module_sp, uint32_t cu_idx,
                  const FileSpec &file_spec, const ArchSpec &arch,
-                 const ConstString *object_name, off_t object_offset,
+                 ConstString object_name, off_t object_offset,
                  const llvm::sys::TimePoint<> object_mod_time)
       : Module(file_spec, arch, object_name, object_offset, object_mod_time),
         m_exe_module_wp(exe_module_sp), m_cu_idx(cu_idx) {}
@@ -459,7 +459,7 @@ Module *SymbolFileDWARFDebugMap::GetModuleByCompUnitInfo(
                              .c_str());
       comp_unit_info->oso_sp->module_sp = std::make_shared<DebugMapModule>(
           obj_file->GetModule(), GetCompUnitInfoIndex(comp_unit_info), oso_file,
-          oso_arch, oso_object ? &oso_object : nullptr, 0,
+          oso_arch, oso_object, 0,
           oso_object ? comp_unit_info->oso_mod_time : llvm::sys::TimePoint<>());
 
       if (oso_object && !comp_unit_info->oso_sp->module_sp->GetObjectFile() &&