[lldb] Modernize Platform::GetOSBuildString

lldb/include/lldb/Target/Platform.h

@@ -212,7 +212,7 @@ public:
 
   bool SetOSVersion(llvm::VersionTuple os_version);
 
-  bool GetOSBuildString(std::string &s);
+  llvm::Optional<std::string> GetOSBuildString();
 
   bool GetOSKernelDescription(std::string &s);
 
@@ -240,9 +240,8 @@ public:
   // HostInfo::GetOSVersion().
   virtual bool GetRemoteOSVersion() { return false; }
 
-  virtual bool GetRemoteOSBuildString(std::string &s) {
-    s.clear();
-    return false;
+  virtual llvm::Optional<std::string> GetRemoteOSBuildString() {
+    return llvm::None;
   }
 
   virtual bool GetRemoteOSKernelDescription(std::string &s) {

lldb/include/lldb/Target/RemoteAwarePlatform.h

@@ -64,7 +64,7 @@ public:
                          FileSpec &local_file) override;
 
   bool GetRemoteOSVersion() override;
-  bool GetRemoteOSBuildString(std::string &s) override;
+  llvm::Optional<std::string> GetRemoteOSBuildString() override;
   bool GetRemoteOSKernelDescription(std::string &s) override;
   ArchSpec GetRemoteSystemArchitecture() override;
 

lldb/source/API/SBPlatform.cpp

@@ -458,13 +458,11 @@ const char *SBPlatform::GetOSBuild() {
 
   PlatformSP platform_sp(GetSP());
   if (platform_sp) {
-    std::string s;
-    if (platform_sp->GetOSBuildString(s)) {
-      if (!s.empty()) {
-        // Const-ify the string so we don't need to worry about the lifetime of
-        // the string
-        return ConstString(s.c_str()).GetCString();
-      }
+    std::string s = platform_sp->GetOSBuildString().getValueOr("");
+    if (!s.empty()) {
+      // Const-ify the string so we don't need to worry about the lifetime of
+      // the string
+      return ConstString(s).GetCString();
     }
   }
   return nullptr;

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

@@ -630,13 +630,12 @@ Status PlatformRemoteDarwinDevice::GetSharedModule(
 uint32_t PlatformRemoteDarwinDevice::GetConnectedSDKIndex() {
   if (IsConnected()) {
     if (m_connected_module_sdk_idx == UINT32_MAX) {
-      std::string build;
-      if (GetRemoteOSBuildString(build)) {
+      if (llvm::Optional<std::string> build = GetRemoteOSBuildString()) {
         const uint32_t num_sdk_infos = m_sdk_directory_infos.size();
         for (uint32_t i = 0; i < num_sdk_infos; ++i) {
           const SDKDirectoryInfo &sdk_dir_info = m_sdk_directory_infos[i];
           if (strstr(sdk_dir_info.directory.GetFilename().AsCString(""),
-                     build.c_str())) {
+                     build->c_str())) {
             m_connected_module_sdk_idx = i;
           }
         }

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

@@ -163,8 +163,8 @@ lldb_private::Status PlatformRemoteMacOSX::GetFileWithUUID(
 #if !defined(__linux__)
     local_os_build = HostInfo::GetOSBuildString().getValueOr("");
 #endif
-    std::string remote_os_build;
-    m_remote_platform_sp->GetOSBuildString(remote_os_build);
+    llvm::Optional<std::string> remote_os_build =
+        m_remote_platform_sp->GetOSBuildString();
     if (local_os_build == remote_os_build) {
       // same OS version: the local file is good enough
       local_file = platform_file;

lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.cpp

@@ -241,8 +241,8 @@ bool PlatformRemoteGDBServer::GetRemoteOSVersion() {
   return !m_os_version.empty();
 }
 
-bool PlatformRemoteGDBServer::GetRemoteOSBuildString(std::string &s) {
-  return m_gdb_client.GetOSBuildString(s);
+llvm::Optional<std::string> PlatformRemoteGDBServer::GetRemoteOSBuildString() {
+  return m_gdb_client.GetOSBuildString();
 }
 
 bool PlatformRemoteGDBServer::GetRemoteOSKernelDescription(std::string &s) {

lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h

@@ -79,7 +79,7 @@ public:
 
   bool GetRemoteOSVersion() override;
 
-  bool GetRemoteOSBuildString(std::string &s) override;
+  llvm::Optional<std::string> GetRemoteOSBuildString() override;
 
   bool GetRemoteOSKernelDescription(std::string &s) override;
 

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp

@@ -970,15 +970,12 @@ llvm::VersionTuple GDBRemoteCommunicationClient::GetMacCatalystVersion() {
   return m_maccatalyst_version;
 }
 
-bool GDBRemoteCommunicationClient::GetOSBuildString(std::string &s) {
+llvm::Optional<std::string> GDBRemoteCommunicationClient::GetOSBuildString() {
   if (GetHostInfo()) {
-    if (!m_os_build.empty()) {
-      s = m_os_build;
-      return true;
-    }
+    if (!m_os_build.empty())
+      return m_os_build;
   }
-  s.clear();
-  return false;
+  return llvm::None;
 }
 
 bool GDBRemoteCommunicationClient::GetOSKernelDescription(std::string &s) {

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h

@@ -239,7 +239,7 @@ public:
 
   llvm::VersionTuple GetMacCatalystVersion();
 
-  bool GetOSBuildString(std::string &s);
+  llvm::Optional<std::string> GetOSBuildString();
 
   bool GetOSKernelDescription(std::string &s);
 

lldb/source/Target/Platform.cpp

@@ -398,7 +398,6 @@ Platform::Platform(bool is_host)
 Platform::~Platform() = default;
 
 void Platform::GetStatus(Stream &strm) {
-  std::string s;
   strm.Format("  Platform: {0}\n", GetPluginName());
 
   ArchSpec arch(GetSystemArchitecture());
@@ -414,8 +413,8 @@ void Platform::GetStatus(Stream &strm) {
   if (!os_version.empty()) {
     strm.Format("OS Version: {0}", os_version.getAsString());
 
-    if (GetOSBuildString(s))
-      strm.Printf(" (%s)", s.c_str());
+    if (llvm::Optional<std::string> s = GetOSBuildString())
+      strm.Format(" ({0})", *s);
 
     strm.EOL();
   }
@@ -440,6 +439,7 @@ void Platform::GetStatus(Stream &strm) {
   if (!specific_info.empty())
     strm.Printf("Platform-specific connection: %s\n", specific_info.c_str());
 
+  std::string s;
   if (GetOSKernelDescription(s))
     strm.Printf("    Kernel: %s\n", s.c_str());
 }
@@ -486,14 +486,10 @@ llvm::VersionTuple Platform::GetOSVersion(Process *process) {
   return llvm::VersionTuple();
 }
 
-bool Platform::GetOSBuildString(std::string &s) {
-  if (IsHost()) {
-    llvm::Optional<std::string> str = HostInfo::GetOSBuildString();
-    s = str.getValueOr("");
-    return str.hasValue();
-  }
-  s.clear();
-  return GetRemoteOSBuildString(s);
+llvm::Optional<std::string> Platform::GetOSBuildString() {
+  if (IsHost())
+    return HostInfo::GetOSBuildString();
+  return GetRemoteOSBuildString();
 }
 
 bool Platform::GetOSKernelDescription(std::string &s) {

lldb/source/Target/RemoteAwarePlatform.cpp

@@ -332,11 +332,10 @@ bool RemoteAwarePlatform::GetRemoteOSVersion() {
   return false;
 }
 
-bool RemoteAwarePlatform::GetRemoteOSBuildString(std::string &s) {
+llvm::Optional<std::string> RemoteAwarePlatform::GetRemoteOSBuildString() {
   if (m_remote_platform_sp)
-    return m_remote_platform_sp->GetRemoteOSBuildString(s);
-  s.clear();
-  return false;
+    return m_remote_platform_sp->GetRemoteOSBuildString();
+  return llvm::None;
 }
 
 bool RemoteAwarePlatform::GetRemoteOSKernelDescription(std::string &s) {