1 files changed, 45 insertions, 19 deletions

diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.cpp
index 859b693477a9..bdd5c29db848 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCClassDescriptorV2.cpp
@@ -1,5 +1,4 @@
-//===-- AppleObjCClassDescriptorV2.cpp -----------------------------*- C++
-//-*-===//
+//===-- AppleObjCClassDescriptorV2.cpp ------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -17,7 +16,7 @@ using namespace lldb_private;
 
 bool ClassDescriptorV2::Read_objc_class(
     Process *process, std::unique_ptr<objc_class_t> &objc_class) const {
-  objc_class.reset(new objc_class_t);
+  objc_class = std::make_unique<objc_class_t>();
 
   bool ret = objc_class->Read(process, m_objc_class_ptr);
 
@@ -198,14 +197,14 @@ bool ClassDescriptorV2::Read_class_row(
     return false;
 
   if (class_row_t_flags & RW_REALIZED) {
-    class_rw.reset(new class_rw_t);
+    class_rw = std::make_unique<class_rw_t>();
 
     if (!class_rw->Read(process, objc_class.m_data_ptr)) {
       class_rw.reset();
       return false;
     }
 
-    class_ro.reset(new class_ro_t);
+    class_ro = std::make_unique<class_ro_t>();
 
     if (!class_ro->Read(process, class_rw->m_ro_ptr)) {
       class_rw.reset();
@@ -213,7 +212,7 @@ bool ClassDescriptorV2::Read_class_row(
       return false;
     }
   } else {
-    class_ro.reset(new class_ro_t);
+    class_ro = std::make_unique<class_ro_t>();
 
     if (!class_ro->Read(process, objc_class.m_data_ptr)) {
       class_ro.reset();
@@ -242,15 +241,20 @@ bool ClassDescriptorV2::method_list_t::Read(Process *process,
 
   lldb::offset_t cursor = 0;
 
-  m_entsize = extractor.GetU32_unchecked(&cursor) & ~(uint32_t)3;
+  uint32_t entsize = extractor.GetU32_unchecked(&cursor);
+  m_is_small = (entsize & 0x80000000) != 0;
+  m_has_direct_selector = (entsize & 0x40000000) != 0;
+  m_entsize = entsize & 0xfffc;
   m_count = extractor.GetU32_unchecked(&cursor);
   m_first_ptr = addr + cursor;
 
   return true;
 }
 
-bool ClassDescriptorV2::method_t::Read(Process *process, lldb::addr_t addr) {
-  size_t size = GetSize(process);
+bool ClassDescriptorV2::method_t::Read(Process *process, lldb::addr_t addr,
+                                       bool is_small, bool has_direct_sel) {
+  size_t ptr_size = process->GetAddressByteSize();
+  size_t size = GetSize(process, is_small);
 
   DataBufferHeap buffer(size, '\0');
   Status error;
@@ -261,13 +265,30 @@ bool ClassDescriptorV2::method_t::Read(Process *process, lldb::addr_t addr) {
   }
 
   DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
-                          process->GetAddressByteSize());
-
+                          ptr_size);
   lldb::offset_t cursor = 0;
 
-  m_name_ptr = extractor.GetAddress_unchecked(&cursor);
-  m_types_ptr = extractor.GetAddress_unchecked(&cursor);
-  m_imp_ptr = extractor.GetAddress_unchecked(&cursor);
+  if (is_small) {
+    uint32_t nameref_offset = extractor.GetU32_unchecked(&cursor);
+    uint32_t types_offset = extractor.GetU32_unchecked(&cursor);
+    uint32_t imp_offset = extractor.GetU32_unchecked(&cursor);
+
+    m_name_ptr = addr + nameref_offset;
+
+    if (!has_direct_sel) {
+      // The SEL offset points to a SELRef. We need to dereference twice.
+      m_name_ptr = process->ReadUnsignedIntegerFromMemory(m_name_ptr, ptr_size,
+                                                          0, error);
+      if (!error.Success())
+        return false;
+    }
+    m_types_ptr = addr + 4 + types_offset;
+    m_imp_ptr = addr + 8 + imp_offset;
+  } else {
+    m_name_ptr = extractor.GetAddress_unchecked(&cursor);
+    m_types_ptr = extractor.GetAddress_unchecked(&cursor);
+    m_imp_ptr = extractor.GetAddress_unchecked(&cursor);
+  }
 
   process->ReadCStringFromMemory(m_name_ptr, m_name, error);
   if (error.Fail()) {
@@ -358,19 +379,24 @@ bool ClassDescriptorV2::Describe(
   if (instance_method_func) {
     std::unique_ptr<method_list_t> base_method_list;
 
-    base_method_list.reset(new method_list_t);
+    base_method_list = std::make_unique<method_list_t>();
     if (!base_method_list->Read(process, class_ro->m_baseMethods_ptr))
       return false;
 
-    if (base_method_list->m_entsize != method_t::GetSize(process))
+    bool is_small = base_method_list->m_is_small;
+    bool has_direct_selector = base_method_list->m_has_direct_selector;
+
+    if (base_method_list->m_entsize != method_t::GetSize(process, is_small))
       return false;
 
     std::unique_ptr<method_t> method;
-    method.reset(new method_t);
+    method = std::make_unique<method_t>();
 
     for (uint32_t i = 0, e = base_method_list->m_count; i < e; ++i) {
-      method->Read(process, base_method_list->m_first_ptr +
-                                (i * base_method_list->m_entsize));
+      method->Read(process,
+                   base_method_list->m_first_ptr +
+                       (i * base_method_list->m_entsize),
+                   is_small, has_direct_selector);
 
       if (instance_method_func(method->m_name.c_str(), method->m_types.c_str()))
         break;