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//===-- ClangFunction.cpp ---------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
// C++ Includes
// Other libraries and framework includes
#include "clang/Frontend/CodeGenAction.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecordLayout.h"
#include "llvm/ExecutionEngine/JIT.h"
#include "llvm/Module.h"
#include "clang/CodeGen/ModuleBuilder.h"
#include "llvm/ADT/StringRef.h"
// Project includes
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectList.h"
#include "lldb/Interpreter/CommandReturnObject.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Target/ThreadPlanCallFunction.h"
#include "lldb/Core/Log.h"
using namespace lldb_private;
//----------------------------------------------------------------------
// ClangFunction constructor
//----------------------------------------------------------------------
ClangFunction::ClangFunction(const char *target_triple, ClangASTContext *ast_context, void *return_qualtype, const Address& functionAddress, const ValueList &arg_value_list) :
ClangExpression (target_triple, NULL),
m_function_addr (functionAddress),
m_function_ptr (NULL),
m_arg_values (arg_value_list),
m_clang_ast_context (ast_context),
m_function_return_qual_type(return_qualtype),
m_wrapper_function_name ("__lldb_caller_function"),
m_wrapper_struct_name ("__lldb_caller_struct"),
m_return_offset(0),
m_compiled (false),
m_JITted (false)
{
}
ClangFunction::ClangFunction(const char *target_triple, Function &function, ClangASTContext *ast_context, const ValueList &arg_value_list) :
ClangExpression (target_triple, NULL),
m_function_ptr (&function),
m_arg_values (arg_value_list),
m_clang_ast_context (ast_context),
m_function_return_qual_type (NULL),
m_wrapper_function_name ("__lldb_function_caller"),
m_wrapper_struct_name ("__lldb_caller_struct"),
m_return_offset(0),
m_compiled (false),
m_JITted (false)
{
m_function_addr = m_function_ptr->GetAddressRange().GetBaseAddress();
m_function_return_qual_type = m_function_ptr->GetReturnType().GetOpaqueClangQualType();
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
ClangFunction::~ClangFunction()
{
}
unsigned
ClangFunction::CompileFunction (Stream &errors)
{
// FIXME: How does clang tell us there's no return value? We need to handle that case.
unsigned num_errors = 0;
if (!m_compiled)
{
std::string return_type_str = ClangASTContext::GetTypeName(m_function_return_qual_type);
// Cons up the function we're going to wrap our call in, then compile it...
// We declare the function "extern "C"" because the compiler might be in C++
// mode which would mangle the name and then we couldn't find it again...
std::string expression;
expression.append ("extern \"C\" void ");
expression.append (m_wrapper_function_name);
expression.append (" (void *input)\n{\n struct ");
expression.append (m_wrapper_struct_name);
expression.append (" \n {\n");
expression.append (" ");
expression.append (return_type_str);
expression.append (" (*fn_ptr) (");
// Get the number of arguments. If we have a function type and it is prototyped,
// trust that, otherwise use the values we were given.
// FIXME: This will need to be extended to handle Variadic functions. We'll need
// to pull the defined arguments out of the function, then add the types from the
// arguments list for the variable arguments.
size_t num_args = -1;
bool trust_function = false;
// GetArgumentCount returns -1 for an unprototyped function.
if (m_function_ptr)
{
num_args = m_function_ptr->GetArgumentCount();
if (num_args != -1)
trust_function = true;
}
if (num_args == -1)
num_args = m_arg_values.GetSize();
std::string args_buffer; // This one stores the definition of all the args in "struct caller".
std::string args_list_buffer; // This one stores the argument list called from the structure.
for (int i = 0; i < num_args; i++)
{
const char *type_string;
std::string type_stdstr;
if (trust_function)
{
type_string = m_function_ptr->GetArgumentTypeAtIndex(i).GetName().AsCString();
}
else
{
Value *arg_value = m_arg_values.GetValueAtIndex(i);
void *clang_qual_type = arg_value->GetOpaqueClangQualType ();
if (clang_qual_type != NULL)
{
type_stdstr = ClangASTContext::GetTypeName(clang_qual_type);
type_string = type_stdstr.c_str();
}
else
{
errors.Printf("Could not determine type of input value %d.", i);
return 1;
}
}
expression.append (type_string);
if (i < num_args - 1)
expression.append (", ");
char arg_buf[32];
args_buffer.append (" ");
args_buffer.append (type_string);
snprintf(arg_buf, 31, "arg_%d", i);
args_buffer.push_back (' ');
args_buffer.append (arg_buf);
args_buffer.append (";\n");
args_list_buffer.append ("__lldb_fn_data->");
args_list_buffer.append (arg_buf);
if (i < num_args - 1)
args_list_buffer.append (", ");
}
expression.append (");\n"); // Close off the function calling prototype.
expression.append (args_buffer);
expression.append (" ");
expression.append (return_type_str);
expression.append (" return_value;");
expression.append ("\n };\n struct ");
expression.append (m_wrapper_struct_name);
expression.append ("* __lldb_fn_data = (struct ");
expression.append (m_wrapper_struct_name);
expression.append (" *) input;\n");
expression.append (" __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr (");
expression.append (args_list_buffer);
expression.append (");\n}\n");
Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP);
if (log)
log->Printf ("Expression: \n\n%s\n\n", expression.c_str());
// Okay, now compile this expression:
num_errors = ParseBareExpression (expression.c_str(), errors);
m_compiled = (num_errors == 0);
if (m_compiled)
{
using namespace clang;
CompilerInstance *compiler_instance = GetCompilerInstance();
ASTContext &ast_context = compiler_instance->getASTContext();
DeclarationName wrapper_func_name(&ast_context.Idents.get(m_wrapper_function_name.c_str()));
FunctionDecl::lookup_result func_lookup = ast_context.getTranslationUnitDecl()->lookup(wrapper_func_name);
if (func_lookup.first == func_lookup.second)
return false;
FunctionDecl *wrapper_func = dyn_cast<FunctionDecl> (*(func_lookup.first));
if (!wrapper_func)
return false;
DeclarationName wrapper_struct_name(&ast_context.Idents.get(m_wrapper_struct_name.c_str()));
RecordDecl::lookup_result struct_lookup = wrapper_func->lookup(wrapper_struct_name);
if (struct_lookup.first == struct_lookup.second)
return false;
RecordDecl *wrapper_struct = dyn_cast<RecordDecl>(*(struct_lookup.first));
if (!wrapper_struct)
return false;
m_struct_layout = &ast_context.getASTRecordLayout (wrapper_struct);
if (!m_struct_layout)
{
m_compiled = false;
return 1;
}
m_return_offset = m_struct_layout->getFieldOffset(m_struct_layout->getFieldCount() - 1);
m_return_size = (m_struct_layout->getDataSize() - m_return_offset)/8;
}
}
return num_errors;
}
bool
ClangFunction::WriteFunctionWrapper (ExecutionContext &exc_context, Stream &errors)
{
Process *process = exc_context.process;
if (process == NULL)
return false;
if (!m_JITted)
{
// Next we should JIT it and insert the result into the target program.
if (!JITFunction (exc_context, m_wrapper_function_name.c_str()))
return false;
if (!WriteJITCode (exc_context))
return false;
m_JITted = true;
}
// Next get the call address for the function:
m_wrapper_fun_addr = GetFunctionAddress (m_wrapper_function_name.c_str());
if (m_wrapper_fun_addr == LLDB_INVALID_ADDRESS)
return false;
return true;
}
bool
ClangFunction::WriteFunctionArguments (ExecutionContext &exc_context, lldb::addr_t &args_addr_ref, Stream &errors)
{
return WriteFunctionArguments(exc_context, args_addr_ref, m_function_addr, m_arg_values, errors);
}
// FIXME: Assure that the ValueList we were passed in is consistent with the one that defined this function.
bool
ClangFunction::WriteFunctionArguments (ExecutionContext &exc_context, lldb::addr_t &args_addr_ref, Address function_address, ValueList &arg_values, Stream &errors)
{
// Otherwise, allocate space for the argument passing struct, and write it.
// We use the information in the expression parser AST to
// figure out how to do this...
// We should probably transcode this in this object so we can ditch the compiler instance
// and all its associated data, and just keep the JITTed bytes.
Error error;
using namespace clang;
ExecutionResults return_value = eExecutionSetupError;
Process *process = exc_context.process;
if (process == NULL)
return return_value;
uint64_t struct_size = m_struct_layout->getSize()/8; // Clang returns sizes in bytes.
if (args_addr_ref == LLDB_INVALID_ADDRESS)
{
args_addr_ref = process->AllocateMemory(struct_size, lldb::ePermissionsReadable|lldb::ePermissionsWritable, error);
if (args_addr_ref == LLDB_INVALID_ADDRESS)
return false;
m_wrapper_args_addrs.push_back (args_addr_ref);
}
else
{
// Make sure this is an address that we've already handed out.
if (find (m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(), args_addr_ref) == m_wrapper_args_addrs.end())
{
return false;
}
}
// FIXME: This is fake, and just assumes that it matches that architecture.
// Make a data extractor and put the address into the right byte order & size.
uint64_t fun_addr = function_address.GetLoadAddress(exc_context.process);
int first_offset = m_struct_layout->getFieldOffset(0)/8;
process->WriteMemory(args_addr_ref + first_offset, &fun_addr, 8, error);
// FIXME: We will need to extend this for Variadic functions.
Error value_error;
size_t num_args = arg_values.GetSize();
if (num_args != m_arg_values.GetSize())
{
errors.Printf ("Wrong number of arguments - was: %d should be: %d", num_args, m_arg_values.GetSize());
return false;
}
for (int i = 0; i < num_args; i++)
{
// FIXME: We should sanity check sizes.
int offset = m_struct_layout->getFieldOffset(i+1)/8; // Clang sizes are in bytes.
Value *arg_value = arg_values.GetValueAtIndex(i);
// FIXME: For now just do scalars:
// Special case: if it's a pointer, don't do anything (the ABI supports passing cstrings)
if (arg_value->GetValueType() == Value::eValueTypeHostAddress &&
arg_value->GetContextType() == Value::eContextTypeOpaqueClangQualType &&
ClangASTContext::IsPointerType(arg_value->GetValueOpaqueClangQualType()))
continue;
const Scalar &arg_scalar = arg_value->ResolveValue(&exc_context, m_clang_ast_context->getASTContext());
int byte_size = arg_scalar.GetByteSize();
std::vector<uint8_t> buffer;
buffer.resize(byte_size);
DataExtractor value_data;
arg_scalar.GetData (value_data);
value_data.ExtractBytes(0, byte_size, process->GetByteOrder(), buffer.data());
process->WriteMemory(args_addr_ref + offset, buffer.data(), byte_size, error);
}
return true;
}
bool
ClangFunction::InsertFunction (ExecutionContext &exc_context, lldb::addr_t &args_addr_ref, Stream &errors)
{
using namespace clang;
if (CompileFunction(errors) != 0)
return false;
if (!WriteFunctionWrapper(exc_context, errors))
return false;
if (!WriteFunctionArguments(exc_context, args_addr_ref, errors))
return false;
Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP);
if (log)
log->Printf ("Call Address: 0x%llx Struct Address: 0x%llx.\n", m_wrapper_fun_addr, args_addr_ref);
return true;
}
ThreadPlan *
ClangFunction::GetThreadPlanToCallFunction (ExecutionContext &exc_context, lldb::addr_t &args_addr, Stream &errors, bool stop_others, bool discard_on_error)
{
// FIXME: Use the errors Stream for better error reporting.
Process *process = exc_context.process;
if (process == NULL)
{
errors.Printf("Can't call a function without a process.");
return NULL;
}
// Okay, now run the function:
Address wrapper_address (NULL, m_wrapper_fun_addr);
ThreadPlan *new_plan = new ThreadPlanCallFunction (*exc_context.thread,
wrapper_address,
args_addr,
stop_others, discard_on_error);
return new_plan;
}
bool
ClangFunction::FetchFunctionResults (ExecutionContext &exc_context, lldb::addr_t args_addr, Value &ret_value)
{
// Read the return value - it is the last field in the struct:
// FIXME: How does clang tell us there's no return value? We need to handle that case.
std::vector<uint8_t> data_buffer;
data_buffer.resize(m_return_size);
Process *process = exc_context.process;
Error error;
size_t bytes_read = process->ReadMemory(args_addr + m_return_offset/8, data_buffer.data(), m_return_size, error);
if (bytes_read == 0)
{
return false;
}
if (bytes_read < m_return_size)
return false;
DataExtractor data(data_buffer.data(), m_return_size, process->GetByteOrder(), process->GetAddressByteSize());
// FIXME: Assuming an integer scalar for now:
uint32_t offset = 0;
uint64_t return_integer = data.GetMaxU64(&offset, m_return_size);
ret_value.SetContext (Value::eContextTypeOpaqueClangQualType, m_function_return_qual_type);
ret_value.SetValueType(Value::eValueTypeScalar);
ret_value.GetScalar() = return_integer;
return true;
}
void
ClangFunction::DeallocateFunctionResults (ExecutionContext &exc_context, lldb::addr_t args_addr)
{
std::list<lldb::addr_t>::iterator pos;
pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(), args_addr);
if (pos != m_wrapper_args_addrs.end())
m_wrapper_args_addrs.erase(pos);
exc_context.process->DeallocateMemory(args_addr);
}
ClangFunction::ExecutionResults
ClangFunction::ExecuteFunction(ExecutionContext &exc_context, Stream &errors, Value &results)
{
return ExecuteFunction (exc_context, errors, 1000, true, results);
}
ClangFunction::ExecutionResults
ClangFunction::ExecuteFunction(ExecutionContext &exc_context, Stream &errors, bool stop_others, Value &results)
{
return ExecuteFunction (exc_context, NULL, errors, stop_others, NULL, false, results);
}
ClangFunction::ExecutionResults
ClangFunction::ExecuteFunction(
ExecutionContext &exc_context,
Stream &errors,
uint32_t single_thread_timeout_usec,
bool try_all_threads,
Value &results)
{
return ExecuteFunction (exc_context, NULL, errors, true, single_thread_timeout_usec, try_all_threads, results);
}
ClangFunction::ExecutionResults
ClangFunction::ExecuteFunction(
ExecutionContext &exc_context,
lldb::addr_t *args_addr_ptr,
Stream &errors,
bool stop_others,
uint32_t single_thread_timeout_usec,
bool try_all_threads,
Value &results)
{
using namespace clang;
ExecutionResults return_value = eExecutionSetupError;
Process *process = exc_context.process;
lldb::addr_t args_addr;
if (args_addr_ptr != NULL)
args_addr = *args_addr_ptr;
else
args_addr = LLDB_INVALID_ADDRESS;
if (CompileFunction(errors) != 0)
return eExecutionSetupError;
if (args_addr == LLDB_INVALID_ADDRESS)
{
if (!InsertFunction(exc_context, args_addr, errors))
return eExecutionSetupError;
}
lldb::ThreadPlanSP call_plan_sp(GetThreadPlanToCallFunction(exc_context, args_addr, errors, stop_others, false));
ThreadPlanCallFunction *call_plan_ptr = static_cast<ThreadPlanCallFunction *> (call_plan_sp.get());
if (args_addr_ptr != NULL)
*args_addr_ptr = args_addr;
if (call_plan_sp == NULL)
return return_value;
call_plan_sp->SetPrivate(true);
exc_context.thread->QueueThreadPlan(call_plan_sp, true);
// We need to call the function synchronously, so spin waiting for it to return.
// If we get interrupted while executing, we're going to lose our context, and
// won't be able to gather the result at this point.
TimeValue* timeout_ptr = NULL;
TimeValue real_timeout;
if (single_thread_timeout_usec != 0)
{
real_timeout = TimeValue::Now();
real_timeout.OffsetWithMicroSeconds(single_thread_timeout_usec);
timeout_ptr = &real_timeout;
}
process->Resume ();
while (1)
{
lldb::EventSP event_sp;
// Now wait for the process to stop again:
// FIXME: Probably want a time out.
lldb::StateType stop_state = process->WaitForStateChangedEvents (timeout_ptr, event_sp);
if (stop_state == lldb::eStateInvalid && timeout_ptr != NULL)
{
// Right now this is the only way to tell we've timed out...
// We should interrupt the process here...
// Not really sure what to do if Halt fails here...
Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP);
if (log)
log->Printf ("Running function with timeout: %d timed out, trying with all threads enabled.", single_thread_timeout_usec);
if (process->Halt().Success())
{
timeout_ptr = NULL;
lldb::StateType stop_state = process->WaitForStateChangedEvents (timeout_ptr, event_sp);
if (stop_state == lldb::eStateInvalid)
{
errors.Printf ("Got an invalid stop state after halt.");
}
else if (stop_state != lldb::eStateStopped)
{
StreamString s;
event_sp->Dump (&s);
errors.Printf("Didn't get a stopped event after Halting the target, got: \"%s\"", s.GetData());
}
if (try_all_threads)
{
// Between the time that we got the timeout and the time we halted, but target
// might have actually completed the plan. If so, we're done.
if (exc_context.thread->IsThreadPlanDone (call_plan_sp.get()))
{
return_value = eExecutionCompleted;
break;
}
call_plan_ptr->SetStopOthers (false);
process->Resume();
continue;
}
else
return eExecutionInterrupted;
}
}
if (stop_state == lldb::eStateRunning || stop_state == lldb::eStateStepping)
continue;
if (exc_context.thread->IsThreadPlanDone (call_plan_sp.get()))
{
return_value = eExecutionCompleted;
break;
}
else if (exc_context.thread->WasThreadPlanDiscarded (call_plan_sp.get()))
{
return_value = eExecutionDiscarded;
break;
}
else
{
return_value = eExecutionInterrupted;
break;
}
}
if (return_value != eExecutionCompleted)
return return_value;
FetchFunctionResults(exc_context, args_addr, results);
if (args_addr_ptr == NULL)
DeallocateFunctionResults(exc_context, args_addr);
return eExecutionCompleted;
}
ClangFunction::ExecutionResults
ClangFunction::ExecuteFunctionWithABI(ExecutionContext &exc_context, Stream &errors, Value &results)
{
// FIXME: Use the errors Stream for better error reporting.
using namespace clang;
ExecutionResults return_value = eExecutionSetupError;
Process *process = exc_context.process;
if (process == NULL)
{
errors.Printf("Can't call a function without a process.");
return return_value;
}
//unsigned int num_args = m_arg_values.GetSize();
//unsigned int arg_index;
//for (arg_index = 0; arg_index < num_args; ++arg_index)
// m_arg_values.GetValueAtIndex(arg_index)->ResolveValue(&exc_context, GetASTContext());
ThreadPlan *call_plan = exc_context.thread->QueueThreadPlanForCallFunction (false,
m_function_addr,
m_arg_values,
true);
if (call_plan == NULL)
return return_value;
call_plan->SetPrivate(true);
// We need to call the function synchronously, so spin waiting for it to return.
// If we get interrupted while executing, we're going to lose our context, and
// won't be able to gather the result at this point.
process->Resume ();
while (1)
{
lldb::EventSP event_sp;
// Now wait for the process to stop again:
// FIXME: Probably want a time out.
lldb::StateType stop_state = process->WaitForStateChangedEvents (NULL, event_sp);
if (stop_state == lldb::eStateRunning || stop_state == lldb::eStateStepping)
continue;
if (exc_context.thread->IsThreadPlanDone (call_plan))
{
return_value = eExecutionCompleted;
break;
}
else if (exc_context.thread->WasThreadPlanDiscarded (call_plan))
{
return_value = eExecutionDiscarded;
break;
}
else
{
return_value = eExecutionInterrupted;
break;
}
}
return eExecutionCompleted;
}