source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntimeV2/AppleObjCRuntimeV2.cpp

//===-- AppleObjCRuntimeV2.cpp --------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "AppleObjCRuntimeV2.h"
#include "AppleObjCTrampolineHandler.h"

#include "lldb/Core/ConstString.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Scalar.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"

#include <vector>

using namespace lldb;
using namespace lldb_private;

static const char *pluginName = "AppleObjCRuntimeV2";
static const char *pluginDesc = "Apple Objective C Language Runtime - Version 2";
static const char *pluginShort = "language.apple.objc.v2";

bool
AppleObjCRuntimeV2::GetObjectDescription (Stream &str, ValueObject &object, ExecutionContextScope *exe_scope)
{
    ExecutionContext exe_ctx;
    exe_scope->Calculate(exe_ctx);
    
    if (!exe_ctx.process)
        return false;
    
    // We need other parts of the exe_ctx, but the processes have to match.
    assert (m_process == exe_ctx.process);
    
    // ObjC objects can only be pointers:
    if (!ClangASTContext::IsPointerType (object.GetOpaqueClangQualType()))
        return NULL;
    
    // Get the function address for the print function.
    const Address *function_address = GetPrintForDebuggerAddr();
    if (!function_address)
        return false;
    
    // Make the argument list: we pass one arg, the address of our pointer, to the print function.
    Scalar scalar;
    
    if (!ClangASTType::GetValueAsScalar (object.GetClangAST(),
                                        object.GetOpaqueClangQualType(),
                                        object.GetDataExtractor(),
                                        0,
                                        object.GetByteSize(),
                                        scalar))
        return NULL;
                        
    Value val(scalar);
    val.SetContext(Value::eContextTypeOpaqueClangQualType, 
                   ClangASTContext::GetVoidPtrType(object.GetClangAST(), false));
                   
    ValueList arg_value_list;
    arg_value_list.PushValue(val);
    
    // This is the return value:
    const char *target_triple = exe_ctx.process->GetTargetTriple().GetCString();
    ClangASTContext *ast_context = exe_ctx.target->GetScratchClangASTContext();
    
    void *return_qualtype = ast_context->GetCStringType(true);
    Value ret;
    ret.SetContext(Value::eContextTypeOpaqueClangQualType, return_qualtype);
    
    // Now we're ready to call the function:
    ClangFunction func(target_triple, ast_context, return_qualtype, *function_address, arg_value_list);
    StreamString error_stream;
    
    lldb::addr_t wrapper_struct_addr = LLDB_INVALID_ADDRESS;
    func.InsertFunction(exe_ctx, wrapper_struct_addr, error_stream);

    ClangFunction::ExecutionResults results 
        = func.ExecuteFunction(exe_ctx, &wrapper_struct_addr, error_stream, true, 1000, true, ret);
    if (results != ClangFunction::eExecutionCompleted)
    {
        str.Printf("Error evaluating Print Object function: %d.\n", results);
        return false;
    }
       
    addr_t result_ptr = ret.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
    
    // FIXME: poor man's strcpy - we should have a "read memory as string interface...
    
    Error error;
    std::vector<char> desc;
    while (1)
    {
        char byte = '\0';
        if (exe_ctx.process->ReadMemory(result_ptr + desc.size(), &byte, 1, error) != 1)
            break;
        
        desc.push_back(byte);

        if (byte == '\0')
            break;
    }
    
    if (!desc.empty())
    {
        str.PutCString(&desc.front());
        return true;
    }
    return false;

}

Address *
AppleObjCRuntimeV2::GetPrintForDebuggerAddr()
{
    if (!m_PrintForDebugger_addr.get())
    {
        ModuleList &modules = m_process->GetTarget().GetImages();
        
        SymbolContextList contexts;
        SymbolContext context;
        
        if((!modules.FindSymbolsWithNameAndType(ConstString ("_NSPrintForDebugger"), eSymbolTypeCode, contexts)) &&
           (!modules.FindSymbolsWithNameAndType(ConstString ("_CFPrintForDebugger"), eSymbolTypeCode, contexts)))
            return NULL;
        
        contexts.GetContextAtIndex(0, context);
        
        m_PrintForDebugger_addr.reset(new Address(context.symbol->GetValue()));
    }
    
    return m_PrintForDebugger_addr.get();
}

lldb::ValueObjectSP
AppleObjCRuntimeV2::GetDynamicValue (lldb::ValueObjectSP in_value, ExecutionContextScope *exe_scope)
{
    lldb::ValueObjectSP ret_sp;
    return ret_sp;
}

bool
AppleObjCRuntimeV2::IsModuleObjCLibrary (const ModuleSP &module_sp)
{
    const FileSpec &module_file_spec = module_sp->GetFileSpec();
    static ConstString ObjCName ("libobjc.A.dylib");
    
    if (module_file_spec)
    {
        if (module_file_spec.GetFilename() == ObjCName)
            return true;
    }
    
    return false;
}

bool
AppleObjCRuntimeV2::ReadObjCLibrary (const ModuleSP &module_sp)
{
    // Maybe check here and if we have a handler already, and the UUID of this module is the same as the one in the
    // current module, then we don't have to reread it?
    m_objc_trampoline_handler_ap.reset(new AppleObjCTrampolineHandler (m_process->GetSP(), module_sp));
    if (m_objc_trampoline_handler_ap.get() != NULL)
    {
        m_read_objc_library = true;
        return true;
    }
    else
        return false;
}

ThreadPlanSP
AppleObjCRuntimeV2::GetStepThroughTrampolinePlan (Thread &thread, bool stop_others)
{
    ThreadPlanSP thread_plan_sp;
    thread_plan_sp = m_objc_trampoline_handler_ap->GetStepThroughDispatchPlan (thread, stop_others);
    return thread_plan_sp;
}

//------------------------------------------------------------------
// Static Functions
//------------------------------------------------------------------
lldb_private::LanguageRuntime *
AppleObjCRuntimeV2::CreateInstance (Process *process, lldb::LanguageType language)
{
    // FIXME: This should be a MacOS or iOS process, and we need to look for the OBJC section to make
    // sure we aren't using the V1 runtime.
    if (language == eLanguageTypeObjC)
        return new AppleObjCRuntimeV2 (process);
    else
        return NULL;
}

void
AppleObjCRuntimeV2::Initialize()
{
    PluginManager::RegisterPlugin (pluginName,
                                   pluginDesc,
                                   CreateInstance);    
}

void
AppleObjCRuntimeV2::Terminate()
{
    PluginManager::UnregisterPlugin (CreateInstance);
}

//------------------------------------------------------------------
// PluginInterface protocol
//------------------------------------------------------------------
const char *
AppleObjCRuntimeV2::GetPluginName()
{
    return pluginName;
}

const char *
AppleObjCRuntimeV2::GetShortPluginName()
{
    return pluginShort;
}

uint32_t
AppleObjCRuntimeV2::GetPluginVersion()
{
    return 1;
}

void
AppleObjCRuntimeV2::GetPluginCommandHelp (const char *command, Stream *strm)
{
}

Error
AppleObjCRuntimeV2::ExecutePluginCommand (Args &command, Stream *strm)
{
    Error error;
    error.SetErrorString("No plug-in command are currently supported.");
    return error;
}

Log *
AppleObjCRuntimeV2::EnablePluginLogging (Stream *strm, Args &command)
{
    return NULL;
}