Merge pull request #6877 from jasonmolenda/platform-darwin-kernel-local-filesystem-scan-lazify-59

lldb PlatformDarwinKernel make local filesystem scan lazy

Author: adrian-prantl

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

@@ -234,12 +234,8 @@ PlatformDarwinKernel::PlatformDarwinKernel(
       m_name_to_kext_path_map_without_dsyms(), m_search_directories(),
       m_search_directories_no_recursing(), m_kernel_binaries_with_dsyms(),
       m_kernel_binaries_without_dsyms(), m_kernel_dsyms_no_binaries(),
-      m_kernel_dsyms_yaas(), m_ios_debug_session(is_ios_debug_session)
-
-{
-  CollectKextAndKernelDirectories();
-  SearchForKextsAndKernelsRecursively();
-}
+      m_kernel_dsyms_yaas(), m_ios_debug_session(is_ios_debug_session),
+      m_kext_scan_flag() {}
 
 /// Destructor.
 ///
@@ -248,6 +244,7 @@ PlatformDarwinKernel::PlatformDarwinKernel(
 PlatformDarwinKernel::~PlatformDarwinKernel() = default;
 
 void PlatformDarwinKernel::GetStatus(Stream &strm) {
+  UpdateKextandKernelsLocalScan();
   Platform::GetStatus(strm);
   strm.Printf(" Debug session type: ");
   if (m_ios_debug_session == eLazyBoolYes)
@@ -716,6 +713,13 @@ PlatformDarwinKernel::GetDWARFBinaryInDSYMBundle(FileSpec dsym_bundle) {
   return results;
 }
 
+void PlatformDarwinKernel::UpdateKextandKernelsLocalScan() {
+  std::call_once(m_kext_scan_flag, [this]() {
+    CollectKextAndKernelDirectories();
+    SearchForKextsAndKernelsRecursively();
+  });
+}
+
 Status PlatformDarwinKernel::GetSharedModule(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
     const FileSpecList *module_search_paths_ptr,
@@ -796,6 +800,7 @@ Status PlatformDarwinKernel::GetSharedModuleKernel(
     llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
   Status error;
   module_sp.reset();
+  UpdateKextandKernelsLocalScan();
 
   // First try all kernel binaries that have a dSYM next to them
   for (auto possible_kernel : m_kernel_binaries_with_dsyms) {

lldb/source/Plugins/Platform/MacOSX/PlatformDarwinKernel.h

@@ -157,6 +157,8 @@ class PlatformDarwinKernel : public PlatformDarwin {
   bool LoadPlatformBinaryAndSetup(Process *process, lldb::addr_t addr,
                                   bool notify) override;
 
+  void UpdateKextandKernelsLocalScan();
+
   // Most of the ivars are assembled under FileSystem::EnumerateDirectory calls
   // where the function being called for each file/directory must be static.
   // We'll pass a this pointer as a baton and access the ivars directly.
@@ -193,6 +195,8 @@ class PlatformDarwinKernel : public PlatformDarwin {
 
   LazyBool m_ios_debug_session;
 
+  std::once_flag m_kext_scan_flag;
+
   PlatformDarwinKernel(const PlatformDarwinKernel &) = delete;
   const PlatformDarwinKernel &operator=(const PlatformDarwinKernel &) = delete;
 };