//===-- 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/AST/ASTContext.h" #include "clang/AST/RecordLayout.h" #include "clang/CodeGen/CodeGenAction.h" #include "clang/CodeGen/ModuleBuilder.h" #include "clang/Frontend/CompilerInstance.h" #include "llvm/ADT/StringRef.h" #include "llvm/ExecutionEngine/ExecutionEngine.h" #include "llvm/Module.h" // Project includes #include "lldb/Expression/ASTStructExtractor.h" #include "lldb/Expression/ClangExpressionParser.h" #include "lldb/Expression/ClangFunction.h" #include "lldb/Symbol/Type.h" #include "lldb/Core/DataExtractor.h" #include "lldb/Core/State.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/RegisterContext.h" #include "lldb/Target/StopInfo.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 ) : m_target_triple (target_triple), m_function_ptr (NULL), m_function_addr (functionAddress), m_function_return_qual_type(return_qualtype), m_clang_ast_context (ast_context), m_wrapper_function_name ("__lldb_caller_function"), m_wrapper_struct_name ("__lldb_caller_struct"), m_wrapper_function_addr (), m_wrapper_args_addrs (), m_arg_values (arg_value_list), m_compiled (false), m_JITted (false) { } ClangFunction::ClangFunction ( const char *target_triple, Function &function, ClangASTContext *ast_context, const ValueList &arg_value_list ) : m_target_triple (target_triple), m_function_ptr (&function), m_function_addr (), m_function_return_qual_type (), m_clang_ast_context (ast_context), m_wrapper_function_name ("__lldb_function_caller"), m_wrapper_struct_name ("__lldb_caller_struct"), m_wrapper_function_addr (), m_wrapper_args_addrs (), m_arg_values (arg_value_list), m_compiled (false), m_JITted (false) { m_function_addr = m_function_ptr->GetAddressRange().GetBaseAddress(); m_function_return_qual_type = m_function_ptr->GetReturnType().GetClangType(); } //---------------------------------------------------------------------- // Destructor //---------------------------------------------------------------------- ClangFunction::~ClangFunction() { } unsigned ClangFunction::CompileFunction (Stream &errors) { if (m_compiled) return 0; // FIXME: How does clang tell us there's no return value? We need to handle that case. unsigned num_errors = 0; 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... m_wrapper_function_text.clear(); m_wrapper_function_text.append ("extern \"C\" void "); m_wrapper_function_text.append (m_wrapper_function_name); m_wrapper_function_text.append (" (void *input)\n{\n struct "); m_wrapper_function_text.append (m_wrapper_struct_name); m_wrapper_function_text.append (" \n {\n"); m_wrapper_function_text.append (" "); m_wrapper_function_text.append (return_type_str); m_wrapper_function_text.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. uint32_t num_args = UINT32_MAX; bool trust_function = false; // GetArgumentCount returns -1 for an unprototyped function. if (m_function_ptr) { int num_func_args = m_function_ptr->GetArgumentCount(); if (num_func_args >= 0) trust_function = true; else num_args = num_func_args; } if (num_args == UINT32_MAX) 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 (size_t 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->GetClangType (); 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; } } m_wrapper_function_text.append (type_string); if (i < num_args - 1) m_wrapper_function_text.append (", "); char arg_buf[32]; args_buffer.append (" "); args_buffer.append (type_string); snprintf(arg_buf, 31, "arg_%zd", 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 (", "); } m_wrapper_function_text.append (");\n"); // Close off the function calling prototype. m_wrapper_function_text.append (args_buffer); m_wrapper_function_text.append (" "); m_wrapper_function_text.append (return_type_str); m_wrapper_function_text.append (" return_value;"); m_wrapper_function_text.append ("\n };\n struct "); m_wrapper_function_text.append (m_wrapper_struct_name); m_wrapper_function_text.append ("* __lldb_fn_data = (struct "); m_wrapper_function_text.append (m_wrapper_struct_name); m_wrapper_function_text.append (" *) input;\n"); m_wrapper_function_text.append (" __lldb_fn_data->return_value = __lldb_fn_data->fn_ptr ("); m_wrapper_function_text.append (args_list_buffer); m_wrapper_function_text.append (");\n}\n"); lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); if (log) log->Printf ("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str()); // Okay, now compile this expression m_parser.reset(new ClangExpressionParser(m_target_triple.c_str(), *this)); num_errors = m_parser->Parse (errors); m_compiled = (num_errors == 0); if (!m_compiled) return num_errors; return num_errors; } bool ClangFunction::WriteFunctionWrapper (ExecutionContext &exe_ctx, Stream &errors) { Process *process = exe_ctx.process; if (!process) return false; if (!m_compiled) return false; if (m_JITted) return true; lldb::addr_t wrapper_function_end; Error jit_error = m_parser->MakeJIT(m_wrapper_function_addr, wrapper_function_end, exe_ctx); if (!jit_error.Success()) return false; return true; } bool ClangFunction::WriteFunctionArguments (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, Stream &errors) { return WriteFunctionArguments(exe_ctx, 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 &exe_ctx, lldb::addr_t &args_addr_ref, Address function_address, ValueList &arg_values, Stream &errors) { // All the information to reconstruct the struct is provided by the // StructExtractor. if (!m_struct_valid) { errors.Printf("Argument information was not correctly parsed, so the function cannot be called."); return false; } Error error; using namespace clang; ExecutionResults return_value = eExecutionSetupError; Process *process = exe_ctx.process; if (process == NULL) return return_value; if (args_addr_ref == LLDB_INVALID_ADDRESS) { args_addr_ref = process->AllocateMemory(m_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(exe_ctx.target); int first_offset = m_member_offsets[0]; 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 (size_t i = 0; i < num_args; i++) { // FIXME: We should sanity check sizes. int offset = m_member_offsets[i+1]; // 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::eContextTypeClangType && ClangASTContext::IsPointerType(arg_value->GetClangType())) continue; const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx, m_clang_ast_context->getASTContext()); int byte_size = arg_scalar.GetByteSize(); std::vector buffer; buffer.resize(byte_size); DataExtractor value_data; arg_scalar.GetData (value_data); value_data.ExtractBytes(0, byte_size, process->GetByteOrder(), &buffer.front()); process->WriteMemory(args_addr_ref + offset, &buffer.front(), byte_size, error); } return true; } bool ClangFunction::InsertFunction (ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, Stream &errors) { using namespace clang; if (CompileFunction(errors) != 0) return false; if (!WriteFunctionWrapper(exe_ctx, errors)) return false; if (!WriteFunctionArguments(exe_ctx, args_addr_ref, errors)) return false; lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); if (log) log->Printf ("Call Address: 0x%llx Struct Address: 0x%llx.\n", m_wrapper_function_addr, args_addr_ref); return true; } ThreadPlan * ClangFunction::GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, lldb::addr_t func_addr, lldb::addr_t &args_addr, Stream &errors, bool stop_others, bool discard_on_error, lldb::addr_t *this_arg) { // FIXME: Use the errors Stream for better error reporting. Process *process = exe_ctx.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, func_addr); ThreadPlan *new_plan = new ThreadPlanCallFunction (*exe_ctx.thread, wrapper_address, args_addr, stop_others, discard_on_error, this_arg); return new_plan; } bool ClangFunction::FetchFunctionResults (ExecutionContext &exe_ctx, 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 data_buffer; data_buffer.resize(m_return_size); Process *process = exe_ctx.process; Error error; size_t bytes_read = process->ReadMemory(args_addr + m_return_offset, &data_buffer.front(), m_return_size, error); if (bytes_read == 0) { return false; } if (bytes_read < m_return_size) return false; DataExtractor data(&data_buffer.front(), 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::eContextTypeClangType, m_function_return_qual_type); ret_value.SetValueType(Value::eValueTypeScalar); ret_value.GetScalar() = return_integer; return true; } void ClangFunction::DeallocateFunctionResults (ExecutionContext &exe_ctx, lldb::addr_t args_addr) { std::list::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); exe_ctx.process->DeallocateMemory(args_addr); } ClangFunction::ExecutionResults ClangFunction::ExecuteFunction(ExecutionContext &exe_ctx, Stream &errors, Value &results) { return ExecuteFunction (exe_ctx, errors, 1000, true, results); } ClangFunction::ExecutionResults ClangFunction::ExecuteFunction(ExecutionContext &exe_ctx, Stream &errors, bool stop_others, Value &results) { const bool try_all_threads = false; const bool discard_on_error = true; return ExecuteFunction (exe_ctx, NULL, errors, stop_others, NULL, try_all_threads, discard_on_error, results); } ClangFunction::ExecutionResults ClangFunction::ExecuteFunction( ExecutionContext &exe_ctx, Stream &errors, uint32_t single_thread_timeout_usec, bool try_all_threads, Value &results) { const bool stop_others = true; const bool discard_on_error = true; return ExecuteFunction (exe_ctx, NULL, errors, stop_others, single_thread_timeout_usec, try_all_threads, discard_on_error, results); } // This is the static function ClangFunction::ExecutionResults ClangFunction::ExecuteFunction ( ExecutionContext &exe_ctx, lldb::addr_t function_address, lldb::addr_t &void_arg, bool stop_others, bool try_all_threads, bool discard_on_error, uint32_t single_thread_timeout_usec, Stream &errors, lldb::addr_t *this_arg) { // Save this value for restoration of the execution context after we run uint32_t tid = exe_ctx.thread->GetIndexID(); // N.B. Running the target may unset the currently selected thread and frame. We don't want to do that either, // so we should arrange to reset them as well. lldb::ThreadSP selected_thread_sp = exe_ctx.process->GetThreadList().GetSelectedThread(); lldb::StackFrameSP selected_frame_sp; uint32_t selected_tid; if (selected_thread_sp != NULL) { selected_tid = selected_thread_sp->GetIndexID(); selected_frame_sp = selected_thread_sp->GetSelectedFrame(); } else { selected_tid = LLDB_INVALID_THREAD_ID; } ClangFunction::ExecutionResults return_value = eExecutionSetupError; lldb::ThreadPlanSP call_plan_sp(ClangFunction::GetThreadPlanToCallFunction(exe_ctx, function_address, void_arg, errors, stop_others, discard_on_error, this_arg)); ThreadPlanCallFunction *call_plan_ptr = static_cast (call_plan_sp.get()); if (call_plan_sp == NULL) return eExecutionSetupError; call_plan_sp->SetPrivate(true); exe_ctx.thread->QueueThreadPlan(call_plan_sp, true); Listener listener("ClangFunction temporary listener"); exe_ctx.process->HijackProcessEvents(&listener); Error resume_error = exe_ctx.process->Resume (); if (!resume_error.Success()) { errors.Printf("Error resuming inferior: \"%s\".\n", resume_error.AsCString()); exe_ctx.process->RestoreProcessEvents(); return eExecutionSetupError; } // 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. // We set the timeout AFTER the resume, since the resume takes some time and we // don't want to charge that to the timeout. 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; } lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); while (1) { lldb::EventSP event_sp; lldb::StateType stop_state = lldb::eStateInvalid; // Now wait for the process to stop again: bool got_event = listener.WaitForEvent (timeout_ptr, event_sp); if (!got_event) { // 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... if (log) if (try_all_threads) log->Printf ("Running function with timeout: %d timed out, trying with all threads enabled.", single_thread_timeout_usec); else log->Printf ("Running function with timeout: %d timed out, abandoning execution.", single_thread_timeout_usec); if (exe_ctx.process->Halt().Success()) { timeout_ptr = NULL; if (log) log->Printf ("Halt succeeded."); // 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. Note, I call WFE here with a short // timeout to got_event = listener.WaitForEvent(NULL, event_sp); if (got_event) { stop_state = Process::ProcessEventData::GetStateFromEvent(event_sp.get()); if (log) { log->Printf ("Stopped with event: %s", StateAsCString(stop_state)); if (stop_state == lldb::eStateStopped && Process::ProcessEventData::GetInterruptedFromEvent(event_sp.get())) log->Printf (" Event was the Halt interruption event."); } if (exe_ctx.thread->IsThreadPlanDone (call_plan_sp.get())) { if (log) log->Printf ("Even though we timed out, the call plan was done. Exiting wait loop."); return_value = eExecutionCompleted; break; } if (try_all_threads && (stop_state == lldb::eStateStopped && Process::ProcessEventData::GetInterruptedFromEvent (event_sp.get()))) { call_plan_ptr->SetStopOthers (false); if (log) log->Printf ("About to resume."); exe_ctx.process->Resume(); continue; } else { exe_ctx.process->RestoreProcessEvents (); return eExecutionInterrupted; } } } } stop_state = Process::ProcessEventData::GetStateFromEvent(event_sp.get()); if (log) log->Printf("Got event: %s.", StateAsCString(stop_state)); if (stop_state == lldb::eStateRunning || stop_state == lldb::eStateStepping) continue; if (exe_ctx.thread->IsThreadPlanDone (call_plan_sp.get())) { return_value = eExecutionCompleted; break; } else if (exe_ctx.thread->WasThreadPlanDiscarded (call_plan_sp.get())) { return_value = eExecutionDiscarded; break; } else { if (log) { StreamString s; event_sp->Dump (&s); StreamString ts; const char *event_explanation; do { const Process::ProcessEventData *event_data = Process::ProcessEventData::GetEventDataFromEvent (event_sp.get()); if (!event_data) { event_explanation = ""; break; } Process *process = event_data->GetProcessSP().get(); if (!process) { event_explanation = ""; break; } ThreadList &thread_list = process->GetThreadList(); uint32_t num_threads = thread_list.GetSize(); uint32_t thread_index; ts.Printf("<%u threads> ", num_threads); for (thread_index = 0; thread_index < num_threads; ++thread_index) { Thread *thread = thread_list.GetThreadAtIndex(thread_index).get(); if (!thread) { ts.Printf(" "); continue; } ts.Printf("<"); RegisterContext *register_context = thread->GetRegisterContext(); if (register_context) ts.Printf("[ip 0x%llx] ", register_context->GetPC()); else ts.Printf("[ip unknown] "); lldb::StopInfoSP stop_info_sp = thread->GetStopInfo(); if (stop_info_sp) { const char *stop_desc = stop_info_sp->GetDescription(); if (stop_desc) ts.PutCString (stop_desc); } ts.Printf(">"); } event_explanation = ts.GetData(); } while (0); if (log) log->Printf("Execution interrupted: %s %s", s.GetData(), event_explanation); } if (discard_on_error && call_plan_sp) { exe_ctx.thread->DiscardThreadPlansUpToPlan (call_plan_sp); } return_value = eExecutionInterrupted; break; } } if (exe_ctx.process) exe_ctx.process->RestoreProcessEvents (); // Thread we ran the function in may have gone away because we ran the target // Check that it's still there. exe_ctx.thread = exe_ctx.process->GetThreadList().FindThreadByIndexID(tid, true).get(); if (exe_ctx.thread) exe_ctx.frame = exe_ctx.thread->GetStackFrameAtIndex(0).get(); // Also restore the current process'es selected frame & thread, since this function calling may // be done behind the user's back. if (selected_tid != LLDB_INVALID_THREAD_ID) { if (exe_ctx.process->GetThreadList().SetSelectedThreadByIndexID (selected_tid)) { // We were able to restore the selected thread, now restore the frame: exe_ctx.process->GetThreadList().GetSelectedThread()->SetSelectedFrame(selected_frame_sp.get()); } } return return_value; } ClangFunction::ExecutionResults ClangFunction::ExecuteFunction( ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr, Stream &errors, bool stop_others, uint32_t single_thread_timeout_usec, bool try_all_threads, bool discard_on_error, Value &results) { using namespace clang; ExecutionResults return_value = eExecutionSetupError; 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(exe_ctx, args_addr, errors)) return eExecutionSetupError; } return_value = ClangFunction::ExecuteFunction(exe_ctx, m_wrapper_function_addr, args_addr, stop_others, try_all_threads, discard_on_error, single_thread_timeout_usec, errors); if (args_addr_ptr != NULL) *args_addr_ptr = args_addr; if (return_value != eExecutionCompleted) return return_value; FetchFunctionResults(exe_ctx, args_addr, results); if (args_addr_ptr == NULL) DeallocateFunctionResults(exe_ctx, args_addr); return eExecutionCompleted; } clang::ASTConsumer * ClangFunction::ASTTransformer (clang::ASTConsumer *passthrough) { return new ASTStructExtractor(passthrough, m_wrapper_struct_name.c_str(), *this); }