[lldb][NFCI] Remove unneeded ConstString conversions

ConstString can be implicitly converted into a llvm::StringRef. This is
very useful in many places, but it also hides places where we are
creating a ConstString only to use it as a StringRef for the entire
lifespan of the ConstString object.

I locally removed the implicit conversion and found some of the places we
were doing this.

Differential Revision: https://reviews.llvm.org/D159237

Author: bulbazord

lldb/include/lldb/Target/Platform.h

@@ -44,7 +44,7 @@ class PlatformProperties : public Properties {
 public:
   PlatformProperties();
 
-  static ConstString GetSettingName();
+  static llvm::StringRef GetSettingName();
 
   bool GetUseModuleCache() const;
   bool SetUseModuleCache(bool use_module_cache);

lldb/source/Core/ModuleList.cpp

@@ -75,8 +75,7 @@ enum {
 } // namespace
 
 ModuleListProperties::ModuleListProperties() {
-  m_collection_sp =
-      std::make_shared<OptionValueProperties>(ConstString("symbols"));
+  m_collection_sp = std::make_shared<OptionValueProperties>("symbols");
   m_collection_sp->Initialize(g_modulelist_properties);
   m_collection_sp->SetValueChangedCallback(ePropertySymLinkPaths,
                                            [this] { UpdateSymlinkMappings(); });

lldb/source/Core/ValueObjectSyntheticFilter.cpp

@@ -311,7 +311,7 @@ ValueObjectSynthetic::GetChildMemberWithName(llvm::StringRef name,
                                              bool can_create) {
   UpdateValueIfNeeded();
 
-  uint32_t index = GetIndexOfChildWithName(ConstString(name));
+  uint32_t index = GetIndexOfChildWithName(name);
 
   if (index == UINT32_MAX)
     return lldb::ValueObjectSP();

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -128,8 +128,8 @@ CommandInterpreter::CommandInterpreter(Debugger &debugger,
                                        bool synchronous_execution)
     : Broadcaster(debugger.GetBroadcasterManager(),
                   CommandInterpreter::GetStaticBroadcasterClass().AsCString()),
-      Properties(OptionValuePropertiesSP(
-          new OptionValueProperties(ConstString("interpreter")))),
+      Properties(
+          OptionValuePropertiesSP(new OptionValueProperties("interpreter"))),
       IOHandlerDelegate(IOHandlerDelegate::Completion::LLDBCommand),
       m_debugger(debugger), m_synchronous_execution(true),
       m_skip_lldbinit_files(false), m_skip_app_init_files(false),

lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp

@@ -98,8 +98,8 @@ enum {
 
 class DynamicLoaderDarwinKernelProperties : public Properties {
 public:
-  static ConstString &GetSettingName() {
-    static ConstString g_setting_name("darwin-kernel");
+  static llvm::StringRef GetSettingName() {
+    static constexpr llvm::StringLiteral g_setting_name("darwin-kernel");
     return g_setting_name;
   }
 

lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp

@@ -89,8 +89,8 @@ enum {
 
 class PluginProperties : public Properties {
 public:
-  static ConstString GetSettingName() {
-    return ConstString(JITLoaderGDB::GetPluginNameStatic());
+  static llvm::StringRef GetSettingName() {
+    return JITLoaderGDB::GetPluginNameStatic();
   }
 
   PluginProperties() {

lldb/source/Plugins/Language/CPlusPlus/GenericBitset.cpp

@@ -38,7 +38,7 @@ class GenericBitsetFrontEnd : public SyntheticChildrenFrontEnd {
   ValueObjectSP GetChildAtIndex(size_t idx) override;
 
 private:
-  ConstString GetDataContainerMemberName();
+  llvm::StringRef GetDataContainerMemberName();
 
   // The lifetime of a ValueObject and all its derivative ValueObjects
   // (children, clones, etc.) is managed by a ClusterManager. These
@@ -66,12 +66,14 @@ GenericBitsetFrontEnd::GenericBitsetFrontEnd(ValueObject &valobj, StdLib stdlib)
   }
 }
 
-ConstString GenericBitsetFrontEnd::GetDataContainerMemberName() {
+llvm::StringRef GenericBitsetFrontEnd::GetDataContainerMemberName() {
+  static constexpr llvm::StringLiteral s_libcxx_case("__first_");
+  static constexpr llvm::StringLiteral s_libstdcpp_case("_M_w");
   switch (m_stdlib) {
   case StdLib::LibCxx:
-    return ConstString("__first_");
+    return s_libcxx_case;
   case StdLib::LibStdcpp:
-    return ConstString("_M_w");
+    return s_libstdcpp_case;
   }
   llvm_unreachable("Unknown StdLib enum");
 }

lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp

@@ -79,8 +79,8 @@ enum {
 
 class PluginProperties : public Properties {
 public:
-  static ConstString GetSettingName() {
-    return ConstString(ObjectFilePECOFF::GetPluginNameStatic());
+  static llvm::StringRef GetSettingName() {
+    return ObjectFilePECOFF::GetPluginNameStatic();
   }
 
   PluginProperties() {

lldb/source/Plugins/Platform/Android/PlatformAndroid.cpp

@@ -43,7 +43,7 @@ class PluginProperties : public Properties {
 public:
   PluginProperties() {
     m_collection_sp = std::make_shared<OptionValueProperties>(
-        ConstString(PlatformAndroid::GetPluginNameStatic(false)));
+        PlatformAndroid::GetPluginNameStatic(false));
     m_collection_sp->Initialize(g_android_properties);
   }
 };
@@ -155,8 +155,8 @@ PlatformSP PlatformAndroid::CreateInstance(bool force, const ArchSpec *arch) {
 }
 
 void PlatformAndroid::DebuggerInitialize(Debugger &debugger) {
-  if (!PluginManager::GetSettingForPlatformPlugin(
-          debugger, ConstString(GetPluginNameStatic(false)))) {
+  if (!PluginManager::GetSettingForPlatformPlugin(debugger,
+                                                  GetPluginNameStatic(false))) {
     PluginManager::CreateSettingForPlatformPlugin(
         debugger, GetGlobalProperties().GetValueProperties(),
         "Properties for the Android platform plugin.",

lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp

@@ -123,8 +123,8 @@ enum {
 
 class PlatformDarwinProperties : public Properties {
 public:
-  static ConstString &GetSettingName() {
-    static ConstString g_setting_name("darwin");
+  static llvm::StringRef GetSettingName() {
+    static constexpr llvm::StringLiteral g_setting_name("darwin");
     return g_setting_name;
   }