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