Reordering KextImageInfo::LoadImageUsingMemoryModule

so we only call ModulesDidLoad at the end of the method
after the new module has been added to the target and
the sections have all been adjusted to their actual
load addresses.  Solves a problem where an operating
system plugin in the kernel could be loaded multiple
times; the first before the binary had even been
added to the target.

<rdar://problem/50523558>

Author: jasonmolenda

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

@@ -791,25 +791,23 @@ bool DynamicLoaderDarwinKernel::KextImageInfo::LoadImageUsingMemoryModule(
       module_spec.GetArchitecture() = target.GetArchitecture();
 
       // For the kernel, we really do need an on-disk file copy of the binary
-      // to do anything useful. This will force a clal to
+      // to do anything useful. This will force a call to dsymForUUID if it
+      // exists, instead of depending on the DebugSymbols preferences being 
+      // set.
       if (IsKernel()) {
         if (Symbols::DownloadObjectAndSymbolFile(module_spec, true)) {
           if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
             m_module_sp = std::make_shared<Module>(module_spec.GetFileSpec(),
                                                    target.GetArchitecture());
-            if (m_module_sp.get() &&
-                m_module_sp->MatchesModuleSpec(module_spec)) {
-              ModuleList loaded_module_list;
-              loaded_module_list.Append(m_module_sp);
-              target.ModulesDidLoad(loaded_module_list);
-            }
           }
         }
       }
 
       // If the current platform is PlatformDarwinKernel, create a ModuleSpec
       // with the filename set to be the bundle ID for this kext, e.g.
       // "com.apple.filesystems.msdosfs", and ask the platform to find it.
+      // PlatformDarwinKernel does a special scan for kexts on the local
+      // system.
       PlatformSP platform_sp(target.GetPlatform());
       if (!m_module_sp && platform_sp) {
         ConstString platform_name(platform_sp->GetPluginName());
@@ -818,7 +816,7 @@ bool DynamicLoaderDarwinKernel::KextImageInfo::LoadImageUsingMemoryModule(
         if (platform_name == g_platform_name) {
           ModuleSpec kext_bundle_module_spec(module_spec);
           FileSpec kext_filespec(m_name.c_str());
-	  FileSpecList search_paths = target.GetExecutableSearchPaths();
+          FileSpecList search_paths = target.GetExecutableSearchPaths();
           kext_bundle_module_spec.GetFileSpec() = kext_filespec;
           platform_sp->GetSharedModule(kext_bundle_module_spec, process,
                                        m_module_sp, &search_paths, nullptr,
@@ -847,7 +845,7 @@ bool DynamicLoaderDarwinKernel::KextImageInfo::LoadImageUsingMemoryModule(
     // UUIDs
     if (m_module_sp) {
       if (m_uuid.IsValid() && m_module_sp->GetUUID() == m_uuid) {
-        target.GetImages().AppendIfNeeded(m_module_sp);
+        target.GetImages().AppendIfNeeded(m_module_sp, false);
         if (IsKernel() &&
             target.GetExecutableModulePointer() != m_module_sp.get()) {
           target.SetExecutableModule(m_module_sp, eLoadDependentsNo);
@@ -945,6 +943,14 @@ bool DynamicLoaderDarwinKernel::KextImageInfo::LoadImageUsingMemoryModule(
     s.Flush();
   }
 
+  // Notify the target about the module being added;
+  // set breakpoints, load dSYM scripts, etc. as needed.
+  if (is_loaded && m_module_sp) {
+    ModuleList loaded_module_list;
+    loaded_module_list.Append(m_module_sp);
+    target.ModulesDidLoad(loaded_module_list);
+  }
+
   return is_loaded;
 }