contrib/llvm/tools/lldb/source/Expression/FunctionCaller.cpp

   1 //===-- FunctionCaller.cpp ---------------------------------------*- C++-*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // C Includes
  11 // C++ Includes
  12 // Other libraries and framework includes
  13
  14 // Project includes
  15 #include "lldb/Expression/FunctionCaller.h"
  16 #include "lldb/Core/Module.h"
  17 #include "lldb/Core/State.h"
  18 #include "lldb/Core/ValueObject.h"
  19 #include "lldb/Core/ValueObjectList.h"
  20 #include "lldb/Expression/DiagnosticManager.h"
  21 #include "lldb/Expression/IRExecutionUnit.h"
  22 #include "lldb/Interpreter/CommandReturnObject.h"
  23 #include "lldb/Symbol/Function.h"
  24 #include "lldb/Symbol/Type.h"
  25 #include "lldb/Target/ExecutionContext.h"
  26 #include "lldb/Target/Process.h"
  27 #include "lldb/Target/RegisterContext.h"
  28 #include "lldb/Target/Target.h"
  29 #include "lldb/Target/Thread.h"
  30 #include "lldb/Target/ThreadPlan.h"
  31 #include "lldb/Target/ThreadPlanCallFunction.h"
  32 #include "lldb/Utility/DataExtractor.h"
  33 #include "lldb/Utility/Log.h"
  34
  35 using namespace lldb_private;
  36
  37 //----------------------------------------------------------------------
  38 // FunctionCaller constructor
  39 //----------------------------------------------------------------------
  40 FunctionCaller::FunctionCaller(ExecutionContextScope &exe_scope,
  41                                const CompilerType &return_type,
  42                                const Address &functionAddress,
  43                                const ValueList &arg_value_list,
  44                                const char *name)
  45     : Expression(exe_scope), m_execution_unit_sp(), m_parser(),
  46       m_jit_module_wp(), m_name(name ? name : "<unknown>"),
  47       m_function_ptr(NULL), m_function_addr(functionAddress),
  48       m_function_return_type(return_type),
  49       m_wrapper_function_name("__lldb_caller_function"),
  50       m_wrapper_struct_name("__lldb_caller_struct"), m_wrapper_args_addrs(),
  51       m_struct_valid(false), m_arg_values(arg_value_list), m_compiled(false),
  52       m_JITted(false) {
  53   m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());
  54   // Can't make a FunctionCaller without a process.
  55   assert(m_jit_process_wp.lock());
  56 }
  57
  58 //----------------------------------------------------------------------
  59 // Destructor
  60 //----------------------------------------------------------------------
  61 FunctionCaller::~FunctionCaller() {
  62   lldb::ProcessSP process_sp(m_jit_process_wp.lock());
  63   if (process_sp) {
  64     lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());
  65     if (jit_module_sp)
  66       process_sp->GetTarget().GetImages().Remove(jit_module_sp);
  67   }
  68 }
  69
  70 bool FunctionCaller::WriteFunctionWrapper(
  71     ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) {
  72   Process *process = exe_ctx.GetProcessPtr();
  73
  74   if (!process)
  75     return false;
  76
  77   lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
  78
  79   if (process != jit_process_sp.get())
  80     return false;
  81
  82   if (!m_compiled)
  83     return false;
  84
  85   if (m_JITted)
  86     return true;
  87
  88   bool can_interpret = false; // should stay that way
  89
  90   Status jit_error(m_parser->PrepareForExecution(
  91       m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,
  92       can_interpret, eExecutionPolicyAlways));
  93
  94   if (!jit_error.Success()) {
  95     diagnostic_manager.Printf(eDiagnosticSeverityError,
  96                               "Error in PrepareForExecution: %s.",
  97                               jit_error.AsCString());
  98     return false;
  99   }
 100
 101   if (m_parser->GetGenerateDebugInfo()) {
 102     lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());
 103
 104     if (jit_module_sp) {
 105       ConstString const_func_name(FunctionName());
 106       FileSpec jit_file;
 107       jit_file.GetFilename() = const_func_name;
 108       jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());
 109       m_jit_module_wp = jit_module_sp;
 110       process->GetTarget().GetImages().Append(jit_module_sp);
 111     }
 112   }
 113   if (process && m_jit_start_addr)
 114     m_jit_process_wp = process->shared_from_this();
 115
 116   m_JITted = true;
 117
 118   return true;
 119 }
 120
 121 bool FunctionCaller::WriteFunctionArguments(
 122     ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
 123     DiagnosticManager &diagnostic_manager) {
 124   return WriteFunctionArguments(exe_ctx, args_addr_ref, m_arg_values,
 125                                 diagnostic_manager);
 126 }
 127
 128 // FIXME: Assure that the ValueList we were passed in is consistent with the one
 129 // that defined this function.
 130
 131 bool FunctionCaller::WriteFunctionArguments(
 132     ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,
 133     ValueList &arg_values, DiagnosticManager &diagnostic_manager) {
 134   // All the information to reconstruct the struct is provided by the
 135   // StructExtractor.
 136   if (!m_struct_valid) {
 137     diagnostic_manager.PutString(eDiagnosticSeverityError,
 138                                  "Argument information was not correctly "
 139                                  "parsed, so the function cannot be called.");
 140     return false;
 141   }
 142
 143   Status error;
 144   lldb::ExpressionResults return_value = lldb::eExpressionSetupError;
 145
 146   Process *process = exe_ctx.GetProcessPtr();
 147
 148   if (process == NULL)
 149     return return_value;
 150
 151   lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
 152
 153   if (process != jit_process_sp.get())
 154     return false;
 155
 156   if (args_addr_ref == LLDB_INVALID_ADDRESS) {
 157     args_addr_ref = process->AllocateMemory(
 158         m_struct_size, lldb::ePermissionsReadable | lldb::ePermissionsWritable,
 159         error);
 160     if (args_addr_ref == LLDB_INVALID_ADDRESS)
 161       return false;
 162     m_wrapper_args_addrs.push_back(args_addr_ref);
 163   } else {
 164     // Make sure this is an address that we've already handed out.
 165     if (find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
 166              args_addr_ref) == m_wrapper_args_addrs.end()) {
 167       return false;
 168     }
 169   }
 170
 171   // TODO: verify fun_addr needs to be a callable address
 172   Scalar fun_addr(
 173       m_function_addr.GetCallableLoadAddress(exe_ctx.GetTargetPtr()));
 174   uint64_t first_offset = m_member_offsets[0];
 175   process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr,
 176                                process->GetAddressByteSize(), error);
 177
 178   // FIXME: We will need to extend this for Variadic functions.
 179
 180   Status value_error;
 181
 182   size_t num_args = arg_values.GetSize();
 183   if (num_args != m_arg_values.GetSize()) {
 184     diagnostic_manager.Printf(
 185         eDiagnosticSeverityError,
 186         "Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "",
 187         (uint64_t)num_args, (uint64_t)m_arg_values.GetSize());
 188     return false;
 189   }
 190
 191   for (size_t i = 0; i < num_args; i++) {
 192     // FIXME: We should sanity check sizes.
 193
 194     uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes.
 195     Value *arg_value = arg_values.GetValueAtIndex(i);
 196
 197     // FIXME: For now just do scalars:
 198
 199     // Special case: if it's a pointer, don't do anything (the ABI supports
 200     // passing cstrings)
 201
 202     if (arg_value->GetValueType() == Value::eValueTypeHostAddress &&
 203         arg_value->GetContextType() == Value::eContextTypeInvalid &&
 204         arg_value->GetCompilerType().IsPointerType())
 205       continue;
 206
 207     const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx);
 208
 209     if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar,
 210                                       arg_scalar.GetByteSize(), error))
 211       return false;
 212   }
 213
 214   return true;
 215 }
 216
 217 bool FunctionCaller::InsertFunction(ExecutionContext &exe_ctx,
 218                                     lldb::addr_t &args_addr_ref,
 219                                     DiagnosticManager &diagnostic_manager) {
 220   if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
 221     return false;
 222   if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager))
 223     return false;
 224   if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager))
 225     return false;
 226
 227   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
 228   if (log)
 229     log->Printf("Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n",
 230                 m_jit_start_addr, args_addr_ref);
 231
 232   return true;
 233 }
 234
 235 lldb::ThreadPlanSP FunctionCaller::GetThreadPlanToCallFunction(
 236     ExecutionContext &exe_ctx, lldb::addr_t args_addr,
 237     const EvaluateExpressionOptions &options,
 238     DiagnosticManager &diagnostic_manager) {
 239   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
 240                                                   LIBLLDB_LOG_STEP));
 241
 242   if (log)
 243     log->Printf("-- [FunctionCaller::GetThreadPlanToCallFunction] Creating "
 244                 "thread plan to call function \"%s\" --",
 245                 m_name.c_str());
 246
 247   // FIXME: Use the errors Stream for better error reporting.
 248   Thread *thread = exe_ctx.GetThreadPtr();
 249   if (thread == NULL) {
 250     diagnostic_manager.PutString(
 251         eDiagnosticSeverityError,
 252         "Can't call a function without a valid thread.");
 253     return NULL;
 254   }
 255
 256   // Okay, now run the function:
 257
 258   Address wrapper_address(m_jit_start_addr);
 259
 260   lldb::addr_t args = {args_addr};
 261
 262   lldb::ThreadPlanSP new_plan_sp(new ThreadPlanCallFunction(
 263       *thread, wrapper_address, CompilerType(), args, options));
 264   new_plan_sp->SetIsMasterPlan(true);
 265   new_plan_sp->SetOkayToDiscard(false);
 266   return new_plan_sp;
 267 }
 268
 269 bool FunctionCaller::FetchFunctionResults(ExecutionContext &exe_ctx,
 270                                           lldb::addr_t args_addr,
 271                                           Value &ret_value) {
 272   // Read the return value - it is the last field in the struct:
 273   // FIXME: How does clang tell us there's no return value?  We need to handle
 274   // that case.
 275   // FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and
 276   // then use GetReturnValueObject
 277   // to fetch the value.  That way we can fetch any values we need.
 278
 279   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
 280                                                   LIBLLDB_LOG_STEP));
 281
 282   if (log)
 283     log->Printf("-- [FunctionCaller::FetchFunctionResults] Fetching function "
 284                 "results for \"%s\"--",
 285                 m_name.c_str());
 286
 287   Process *process = exe_ctx.GetProcessPtr();
 288
 289   if (process == NULL)
 290     return false;
 291
 292   lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());
 293
 294   if (process != jit_process_sp.get())
 295     return false;
 296
 297   Status error;
 298   ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory(
 299       args_addr + m_return_offset, m_return_size, 0, error);
 300
 301   if (error.Fail())
 302     return false;
 303
 304   ret_value.SetCompilerType(m_function_return_type);
 305   ret_value.SetValueType(Value::eValueTypeScalar);
 306   return true;
 307 }
 308
 309 void FunctionCaller::DeallocateFunctionResults(ExecutionContext &exe_ctx,
 310                                                lldb::addr_t args_addr) {
 311   std::list<lldb::addr_t>::iterator pos;
 312   pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(),
 313                   args_addr);
 314   if (pos != m_wrapper_args_addrs.end())
 315     m_wrapper_args_addrs.erase(pos);
 316
 317   exe_ctx.GetProcessRef().DeallocateMemory(args_addr);
 318 }
 319
 320 lldb::ExpressionResults FunctionCaller::ExecuteFunction(
 321     ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr,
 322     const EvaluateExpressionOptions &options,
 323     DiagnosticManager &diagnostic_manager, Value &results) {
 324   lldb::ExpressionResults return_value = lldb::eExpressionSetupError;
 325
 326   // FunctionCaller::ExecuteFunction execution is always just to get the
 327   // result. Do make sure we ignore breakpoints, unwind on error, and don't try
 328   // to debug it.
 329   EvaluateExpressionOptions real_options = options;
 330   real_options.SetDebug(false);
 331   real_options.SetUnwindOnError(true);
 332   real_options.SetIgnoreBreakpoints(true);
 333
 334   lldb::addr_t args_addr;
 335
 336   if (args_addr_ptr != NULL)
 337     args_addr = *args_addr_ptr;
 338   else
 339     args_addr = LLDB_INVALID_ADDRESS;
 340
 341   if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)
 342     return lldb::eExpressionSetupError;
 343
 344   if (args_addr == LLDB_INVALID_ADDRESS) {
 345     if (!InsertFunction(exe_ctx, args_addr, diagnostic_manager))
 346       return lldb::eExpressionSetupError;
 347   }
 348
 349   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
 350                                                   LIBLLDB_LOG_STEP));
 351
 352   if (log)
 353     log->Printf(
 354         "== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==",
 355         m_name.c_str());
 356
 357   lldb::ThreadPlanSP call_plan_sp = GetThreadPlanToCallFunction(
 358       exe_ctx, args_addr, real_options, diagnostic_manager);
 359   if (!call_plan_sp)
 360     return lldb::eExpressionSetupError;
 361
 362   // We need to make sure we record the fact that we are running an expression
 363   // here otherwise this fact will fail to be recorded when fetching an
 364   // Objective-C object description
 365   if (exe_ctx.GetProcessPtr())
 366     exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
 367
 368   return_value = exe_ctx.GetProcessRef().RunThreadPlan(
 369       exe_ctx, call_plan_sp, real_options, diagnostic_manager);
 370
 371   if (log) {
 372     if (return_value != lldb::eExpressionCompleted) {
 373       log->Printf("== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
 374                   "completed abnormally ==",
 375                   m_name.c_str());
 376     } else {
 377       log->Printf("== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "
 378                   "completed normally ==",
 379                   m_name.c_str());
 380     }
 381   }
 382
 383   if (exe_ctx.GetProcessPtr())
 384     exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
 385
 386   if (args_addr_ptr != NULL)
 387     *args_addr_ptr = args_addr;
 388
 389   if (return_value != lldb::eExpressionCompleted)
 390     return return_value;
 391
 392   FetchFunctionResults(exe_ctx, args_addr, results);
 393
 394   if (args_addr_ptr == NULL)
 395     DeallocateFunctionResults(exe_ctx, args_addr);
 396
 397   return lldb::eExpressionCompleted;
 398 }