//===-- 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/ADT/Triple.h" #include "llvm/ExecutionEngine/ExecutionEngine.h" #include "llvm/IR/Module.h" // Project includes #include "lldb/Expression/ASTStructExtractor.h" #include "lldb/Expression/ClangExpressionParser.h" #include "lldb/Expression/ClangFunction.h" #include "lldb/Expression/IRExecutionUnit.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/Target.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 ( ExecutionContextScope &exe_scope, const ClangASTType &return_type, const Address& functionAddress, const ValueList &arg_value_list ) : m_function_ptr (NULL), m_function_addr (functionAddress), m_function_return_type(return_type), m_wrapper_function_name ("__lldb_caller_function"), m_wrapper_struct_name ("__lldb_caller_struct"), m_wrapper_args_addrs (), m_arg_values (arg_value_list), m_compiled (false), m_JITted (false) { m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess()); // Can't make a ClangFunction without a process. assert (m_jit_process_wp.lock()); } ClangFunction::ClangFunction ( ExecutionContextScope &exe_scope, Function &function, ClangASTContext *ast_context, const ValueList &arg_value_list ) : m_function_ptr (&function), m_function_addr (), m_function_return_type (), m_wrapper_function_name ("__lldb_function_caller"), m_wrapper_struct_name ("__lldb_caller_struct"), m_wrapper_args_addrs (), m_arg_values (arg_value_list), m_compiled (false), m_JITted (false) { m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess()); // Can't make a ClangFunction without a process. assert (m_jit_process_wp.lock()); m_function_addr = m_function_ptr->GetAddressRange().GetBaseAddress(); m_function_return_type = m_function_ptr->GetClangType().GetFunctionReturnType(); } //---------------------------------------------------------------------- // 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 (m_function_return_type.GetTypeName().AsCString("")); // 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. ClangASTType function_clang_type; if (m_function_ptr) { function_clang_type = m_function_ptr->GetClangType(); if (function_clang_type) { int num_func_args = function_clang_type.GetFunctionArgumentCount(); if (num_func_args >= 0) { trust_function = true; 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++) { std::string type_name; if (trust_function) { type_name = function_clang_type.GetFunctionArgumentTypeAtIndex(i).GetTypeName().AsCString(""); } else { ClangASTType clang_qual_type = m_arg_values.GetValueAtIndex(i)->GetClangType (); if (clang_qual_type) { type_name = clang_qual_type.GetTypeName().AsCString(""); } else { errors.Printf("Could not determine type of input value %zu.", i); return 1; } } m_wrapper_function_text.append (type_name); if (i < num_args - 1) m_wrapper_function_text.append (", "); char arg_buf[32]; args_buffer.append (" "); args_buffer.append (type_name); snprintf(arg_buf, 31, "arg_%" PRIu64, (uint64_t)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"); Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS)); if (log) log->Printf ("Expression: \n\n%s\n\n", m_wrapper_function_text.c_str()); // Okay, now compile this expression lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); if (jit_process_sp) { m_parser.reset(new ClangExpressionParser(jit_process_sp.get(), *this)); num_errors = m_parser->Parse (errors); } else { errors.Printf("no process - unable to inject function"); num_errors = 1; } 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.GetProcessPtr(); if (!process) return false; lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); if (process != jit_process_sp.get()) return false; if (!m_compiled) return false; if (m_JITted) return true; bool can_interpret = false; // should stay that way Error jit_error (m_parser->PrepareForExecution (m_jit_start_addr, m_jit_end_addr, m_execution_unit_ap, exe_ctx, can_interpret, eExecutionPolicyAlways)); if (!jit_error.Success()) return false; if (process && m_jit_start_addr) m_jit_process_wp = lldb::ProcessWP(process->shared_from_this()); m_JITted = true; 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.GetProcessPtr(); if (process == NULL) return return_value; lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); if (process != jit_process_sp.get()) return false; 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; } } // TODO: verify fun_addr needs to be a callable address Scalar fun_addr (function_address.GetCallableLoadAddress(exe_ctx.GetTargetPtr())); uint64_t first_offset = m_member_offsets[0]; process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr, process->GetAddressByteSize(), 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: %zu should be: %zu", num_args, m_arg_values.GetSize()); return false; } for (size_t i = 0; i < num_args; i++) { // FIXME: We should sanity check sizes. uint64_t 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::eContextTypeInvalid && arg_value->GetClangType().IsPointerType()) continue; const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx); if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar, arg_scalar.GetByteSize(), error)) return false; } 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; Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP)); if (log) log->Printf ("Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n", m_jit_start_addr, args_addr_ref); return true; } ThreadPlan * ClangFunction::GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, lldb::addr_t args_addr, const EvaluateExpressionOptions &options, Stream &errors) { Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP)); if (log) log->Printf("-- [ClangFunction::GetThreadPlanToCallFunction] Creating thread plan to call function --"); // FIXME: Use the errors Stream for better error reporting. Thread *thread = exe_ctx.GetThreadPtr(); if (thread == NULL) { errors.Printf("Can't call a function without a valid thread."); return NULL; } // Okay, now run the function: Address wrapper_address (m_jit_start_addr); lldb::addr_t args = { args_addr }; ThreadPlan *new_plan = new ThreadPlanCallFunction (*thread, wrapper_address, ClangASTType(), args, options); new_plan->SetIsMasterPlan(true); new_plan->SetOkayToDiscard (false); 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. // FIXME: Create our ThreadPlanCallFunction with the return ClangASTType, and then use GetReturnValueObject // to fetch the value. That way we can fetch any values we need. Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP)); if (log) log->Printf("-- [ClangFunction::FetchFunctionResults] Fetching function results --"); Process *process = exe_ctx.GetProcessPtr(); if (process == NULL) return false; lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); if (process != jit_process_sp.get()) return false; Error error; ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory (args_addr + m_return_offset, m_return_size, 0, error); if (error.Fail()) return false; ret_value.SetClangType(m_function_return_type); ret_value.SetValueType(Value::eValueTypeScalar); 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.GetProcessRef().DeallocateMemory(args_addr); } ExecutionResults ClangFunction::ExecuteFunction( ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr, const EvaluateExpressionOptions &options, Stream &errors, Value &results) { using namespace clang; ExecutionResults return_value = eExecutionSetupError; // ClangFunction::ExecuteFunction execution is always just to get the result. Do make sure we ignore // breakpoints, unwind on error, and don't try to debug it. EvaluateExpressionOptions real_options = options; real_options.SetDebug(false); real_options.SetUnwindOnError(true); real_options.SetIgnoreBreakpoints(true); 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; } Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_EXPRESSIONS | LIBLLDB_LOG_STEP)); if (log) log->Printf("== [ClangFunction::ExecuteFunction] Executing function =="); lldb::ThreadPlanSP call_plan_sp (GetThreadPlanToCallFunction (exe_ctx, args_addr, real_options, errors)); if (!call_plan_sp) return eExecutionSetupError; // we need to make sure we record the fact that we are running an expression here // otherwise this fact will fail to be recorded when fetching an Objective-C object description if (exe_ctx.GetProcessPtr()) exe_ctx.GetProcessPtr()->SetRunningUserExpression(true); return_value = exe_ctx.GetProcessRef().RunThreadPlan (exe_ctx, call_plan_sp, real_options, errors); if (log) { if (return_value != eExecutionCompleted) { log->Printf("== [ClangFunction::ExecuteFunction] Execution completed abnormally =="); } else { log->Printf("== [ClangFunction::ExecuteFunction] Execution completed normally =="); } } if (exe_ctx.GetProcessPtr()) exe_ctx.GetProcessPtr()->SetRunningUserExpression(false); 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) { m_struct_extractor.reset(new ASTStructExtractor(passthrough, m_wrapper_struct_name.c_str(), *this)); return m_struct_extractor.get(); }