Clean up PlatformDarwinKernel::GetSharedModule, document (#78652)

lldb/include/lldb/Target/Platform.h

@@ -288,6 +288,32 @@ class Platform : public PluginInterface {
   LocateExecutableScriptingResources(Target *target, Module &module,
                                      Stream &feedback_stream);
 
+  /// \param[in] module_spec
+  ///     The ModuleSpec of a binary to find.
+  ///
+  /// \param[in] process
+  ///     A Process.
+  ///
+  /// \param[out] module_sp
+  ///     A Module that matches the ModuleSpec, if one is found.
+  ///
+  /// \param[in] module_search_paths_ptr
+  ///     Locations to possibly look for a binary that matches the ModuleSpec.
+  ///
+  /// \param[out] old_modules
+  ///     Existing Modules in the Process' Target image list which match
+  ///     the FileSpec.
+  ///
+  /// \param[out] did_create_ptr
+  ///     Optional boolean, nullptr may be passed for this argument.
+  ///     If this method is returning a *new* ModuleSP, this
+  ///     will be set to true.
+  ///     If this method is returning a ModuleSP that is already in the
+  ///     Target's image list, it will be false.
+  ///
+  /// \return
+  ///     The Status object for any errors found while searching for
+  ///     the binary.
   virtual Status GetSharedModule(
       const ModuleSpec &module_spec, Process *process,
       lldb::ModuleSP &module_sp, const FileSpecList *module_search_paths_ptr,

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

@@ -22,6 +22,7 @@
 #include "lldb/Interpreter/OptionValueFileSpecList.h"
 #include "lldb/Interpreter/OptionValueProperties.h"
 #include "lldb/Interpreter/Property.h"
+#include "lldb/Symbol/LocateSymbolFile.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Target/Platform.h"
 #include "lldb/Target/Process.h"
@@ -791,9 +792,10 @@ Status PlatformDarwinKernel::GetSharedModuleKernel(
     const ModuleSpec &module_spec, Process *process, ModuleSP &module_sp,
     const FileSpecList *module_search_paths_ptr,
     llvm::SmallVectorImpl<ModuleSP> *old_modules, bool *did_create_ptr) {
-  Status error;
-  module_sp.reset();
+  assert(module_sp.get() == nullptr);
   UpdateKextandKernelsLocalScan();
+  if (did_create_ptr)
+    *did_create_ptr = false;
 
   // First try all kernel binaries that have a dSYM next to them
   for (auto possible_kernel : m_kernel_binaries_with_dsyms) {
@@ -803,22 +805,19 @@ Status PlatformDarwinKernel::GetSharedModuleKernel(
       module_sp.reset(new Module(kern_spec));
       if (module_sp && module_sp->GetObjectFile() &&
           module_sp->MatchesModuleSpec(kern_spec)) {
-        // module_sp is an actual kernel binary we want to add.
-        if (process) {
-          const bool notify = false;
-          process->GetTarget().GetImages().AppendIfNeeded(module_sp, notify);
-          error.Clear();
-          return error;
-        } else {
-          error = ModuleList::GetSharedModule(kern_spec, module_sp, nullptr,
-                                              nullptr, nullptr);
-          if (module_sp && module_sp->GetObjectFile() &&
-              module_sp->GetObjectFile()->GetType() !=
-                  ObjectFile::Type::eTypeCoreFile) {
-            return error;
-          }
-          module_sp.reset();
-        }
+        // The dSYM is next to the binary (that's the only
+        // way it ends up in the index), but it might be a
+        // .dSYM.yaa that needs to be expanded, don't just
+        // append ".dSYM" to the filename for the SymbolFile.
+        FileSpecList search_paths =
+            process->GetTarget().GetDebugFileSearchPaths();
+        FileSpec dsym_fspec =
+            Symbols::LocateExecutableSymbolFile(kern_spec, search_paths);
+        if (FileSystem::Instance().Exists(dsym_fspec))
+          module_sp->SetSymbolFileFileSpec(dsym_fspec);
+        if (did_create_ptr)
+          *did_create_ptr = true;
+        return {};
       }
     }
   }
@@ -836,36 +835,18 @@ Status PlatformDarwinKernel::GetSharedModuleKernel(
       module_sp.reset(new Module(kern_spec));
       if (module_sp && module_sp->GetObjectFile() &&
           module_sp->MatchesModuleSpec(kern_spec)) {
-        // module_sp is an actual kernel binary we want to add.
-        if (process) {
-          const bool notify = false;
-          process->GetTarget().GetImages().AppendIfNeeded(module_sp, notify);
-          error.Clear();
-          return error;
-        } else {
-          error = ModuleList::GetSharedModule(kern_spec, module_sp, nullptr,
-                                              nullptr, nullptr);
-          if (module_sp && module_sp->GetObjectFile() &&
-              module_sp->GetObjectFile()->GetType() !=
-                  ObjectFile::Type::eTypeCoreFile) {
-            return error;
-          }
-          module_sp.reset();
-        }
+        if (did_create_ptr)
+          *did_create_ptr = true;
+        return {};
       }
     }
   }
 
-  // Give the generic methods, including possibly calling into  DebugSymbols
+  // Give the generic methods, including possibly calling into DebugSymbols
   // framework on macOS systems, a chance.
-  error = PlatformDarwin::GetSharedModule(module_spec, process, module_sp,
-                                          module_search_paths_ptr, old_modules,
-                                          did_create_ptr);
-  if (error.Success() && module_sp.get()) {
-    return error;
-  }
-
-  return error;
+  return PlatformDarwin::GetSharedModule(module_spec, process, module_sp,
+                                         module_search_paths_ptr, old_modules,
+                                         did_create_ptr);
 }
 
 std::vector<lldb_private::FileSpec>