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