[lldb] Change definition of DisassemblerCreateInstance

[bulbazord]

Summary

DissassemblerCreateInstance is a function pointer whos return type is
Disassembler *. But Disassembler::FindPlugin always returns a
DisassemblerSP, so there's no reason why we can't just create a
DisassemblerSP in the first place.

lldb/include/lldb/lldb-private-interfaces.h

 }
 } // namespace llvm
 
 namespace lldb_private {
 typedef lldb::ABISP (*ABICreateInstance)(lldb::ProcessSP process_sp,
                                          const ArchSpec &arch);
 typedef std::unique_ptr<Architecture> (*ArchitectureCreateInstance)(
     const ArchSpec &arch);
-typedef Disassembler *(*DisassemblerCreateInstance)(const ArchSpec &arch,
+typedef lldb::DisassemblerSP (*DisassemblerCreateInstance)(const ArchSpec &arch,
                                                            const char *flavor);
 typedef DynamicLoader *(*DynamicLoaderCreateInstance)(Process *process,
                                                       bool force);
 typedef lldb::JITLoaderSP (*JITLoaderCreateInstance)(Process *process,
                                                      bool force);
 typedef ObjectContainer *(*ObjectContainerCreateInstance)(
     const lldb::ModuleSP &module_sp, lldb::DataBufferSP &data_sp,
     lldb::offset_t data_offset, const FileSpec *file, lldb::offset_t offset,
     lldb::offset_t length);

lldb/source/Core/Disassembler.cpp

LLDB_SCOPED_TIMERF("Disassembler::FindPlugin (arch = %s, plugin_name = %s)",
                      arch.GetArchitectureName(), plugin_name);
 
   DisassemblerCreateInstance create_callback = nullptr;
 
   if (plugin_name) {
     create_callback =
         PluginManager::GetDisassemblerCreateCallbackForPluginName(plugin_name);
     if (create_callback) {
-      DisassemblerSP disassembler_sp(create_callback(arch, flavor));
-
-      if (disassembler_sp)
-        return disassembler_sp;
+      if (auto disasm_sp = create_callback(arch, flavor))
+        return disasm_sp;
     }
   } else {
     for (uint32_t idx = 0;
          (create_callback = PluginManager::GetDisassemblerCreateCallbackAtIndex(
               idx)) != nullptr;
          ++idx) {
-      DisassemblerSP disassembler_sp(create_callback(arch, flavor));
-
-      if (disassembler_sp)
-        return disassembler_sp;
+      if (auto disasm_sp = create_callback(arch, flavor))
+        return disasm_sp;
     }
   }
   return DisassemblerSP();
 }
 
 DisassemblerSP Disassembler::FindPluginForTarget(const Target &target,
                                                  const ArchSpec &arch,
                                                  const char *flavor,

lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.h

public:
 
   // Static Functions
   static void Initialize();
 
   static void Terminate();
 
   static llvm::StringRef GetPluginNameStatic() { return "llvm-mc"; }
 
-  static lldb_private::Disassembler *
-  CreateInstance(const lldb_private::ArchSpec &arch, const char *flavor);
+  static lldb::DisassemblerSP CreateInstance(const lldb_private::ArchSpec &arch,
+                                             const char *flavor);
 
   size_t DecodeInstructions(const lldb_private::Address &base_addr,
                             const lldb_private::DataExtractor &data,
                             lldb::offset_t data_offset, size_t num_instructions,
                             bool append, bool data_from_file) override;
 
   // PluginInterface protocol
   llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }

lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp

m_alternate_disasm_up = MCDisasmInstance::Create(
         triple_str, cpu, features_str.c_str(), flavor, *this);
     if (!m_alternate_disasm_up)
       m_disasm_up.reset();
   }
 }
 
 DisassemblerLLVMC::~DisassemblerLLVMC() = default;
 
-Disassembler *DisassemblerLLVMC::CreateInstance(const ArchSpec &arch,
+lldb::DisassemblerSP DisassemblerLLVMC::CreateInstance(const ArchSpec &arch,
                                                        const char *flavor) {
   if (arch.GetTriple().getArch() != llvm::Triple::UnknownArch) {
-    std::unique_ptr<DisassemblerLLVMC> disasm_up(
-        new DisassemblerLLVMC(arch, flavor));
-
-    if (disasm_up.get() && disasm_up->IsValid())
-      return disasm_up.release();
+    auto disasm_sp = std::make_shared<DisassemblerLLVMC>(arch, flavor);
+    if (disasm_sp && disasm_sp->IsValid())
+      return disasm_sp;
   }
-  return nullptr;
+  return lldb::DisassemblerSP();
 }
 
 size_t DisassemblerLLVMC::DecodeInstructions(const Address &base_addr,
                                              const DataExtractor &data,
                                              lldb::offset_t data_offset,
                                              size_t num_instructions,
                                              bool append, bool data_from_file) {
   if (!append)