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

   1 //===-- LLVMUserExpression.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
  13 // Project includes
  14 #include "lldb/Expression/LLVMUserExpression.h"
  15 #include "lldb/Core/Module.h"
  16 #include "lldb/Core/StreamFile.h"
  17 #include "lldb/Core/ValueObjectConstResult.h"
  18 #include "lldb/Expression/DiagnosticManager.h"
  19 #include "lldb/Expression/ExpressionSourceCode.h"
  20 #include "lldb/Expression/IRExecutionUnit.h"
  21 #include "lldb/Expression/IRInterpreter.h"
  22 #include "lldb/Expression/Materializer.h"
  23 #include "lldb/Host/HostInfo.h"
  24 #include "lldb/Symbol/Block.h"
  25 #include "lldb/Symbol/ClangASTContext.h"
  26 #include "lldb/Symbol/ClangExternalASTSourceCommon.h"
  27 #include "lldb/Symbol/Function.h"
  28 #include "lldb/Symbol/ObjectFile.h"
  29 #include "lldb/Symbol/SymbolVendor.h"
  30 #include "lldb/Symbol/Type.h"
  31 #include "lldb/Symbol/VariableList.h"
  32 #include "lldb/Target/ExecutionContext.h"
  33 #include "lldb/Target/Process.h"
  34 #include "lldb/Target/StackFrame.h"
  35 #include "lldb/Target/Target.h"
  36 #include "lldb/Target/ThreadPlan.h"
  37 #include "lldb/Target/ThreadPlanCallUserExpression.h"
  38 #include "lldb/Utility/ConstString.h"
  39 #include "lldb/Utility/Log.h"
  40 #include "lldb/Utility/StreamString.h"
  41
  42 using namespace lldb_private;
  43
  44 LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope,
  45                                        llvm::StringRef expr,
  46                                        llvm::StringRef prefix,
  47                                        lldb::LanguageType language,
  48                                        ResultType desired_type,
  49                                        const EvaluateExpressionOptions &options)
  50     : UserExpression(exe_scope, expr, prefix, language, desired_type, options),
  51       m_stack_frame_bottom(LLDB_INVALID_ADDRESS),
  52       m_stack_frame_top(LLDB_INVALID_ADDRESS),
  53       m_allow_cxx(false),
  54       m_allow_objc(false),
  55       m_transformed_text(),
  56       m_execution_unit_sp(), m_materializer_ap(), m_jit_module_wp(),
  57       m_enforce_valid_object(true), m_in_cplusplus_method(false),
  58       m_in_objectivec_method(false), m_in_static_method(false),
  59       m_needs_object_ptr(false), m_target(NULL), m_can_interpret(false),
  60       m_materialized_address(LLDB_INVALID_ADDRESS) {}
  61
  62 LLVMUserExpression::~LLVMUserExpression() {
  63   if (m_target) {
  64     lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());
  65     if (jit_module_sp)
  66       m_target->GetImages().Remove(jit_module_sp);
  67   }
  68 }
  69
  70 lldb::ExpressionResults
  71 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager,
  72                               ExecutionContext &exe_ctx,
  73                               const EvaluateExpressionOptions &options,
  74                               lldb::UserExpressionSP &shared_ptr_to_me,
  75                               lldb::ExpressionVariableSP &result) {
  76   // The expression log is quite verbose, and if you're just tracking the
  77   // execution of the
  78   // expression, it's quite convenient to have these logs come out with the STEP
  79   // log as well.
  80   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
  81                                                   LIBLLDB_LOG_STEP));
  82
  83   if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) {
  84     lldb::addr_t struct_address = LLDB_INVALID_ADDRESS;
  85
  86     if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx,
  87                                        struct_address)) {
  88       diagnostic_manager.Printf(
  89           eDiagnosticSeverityError,
  90           "errored out in %s, couldn't PrepareToExecuteJITExpression",
  91           __FUNCTION__);
  92       return lldb::eExpressionSetupError;
  93     }
  94
  95     lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS;
  96     lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS;
  97
  98     if (m_can_interpret) {
  99       llvm::Module *module = m_execution_unit_sp->GetModule();
 100       llvm::Function *function = m_execution_unit_sp->GetFunction();
 101
 102       if (!module || !function) {
 103         diagnostic_manager.PutString(
 104             eDiagnosticSeverityError,
 105             "supposed to interpret, but nothing is there");
 106         return lldb::eExpressionSetupError;
 107       }
 108
 109       Status interpreter_error;
 110
 111       std::vector<lldb::addr_t> args;
 112
 113       if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {
 114         diagnostic_manager.Printf(eDiagnosticSeverityError,
 115                                   "errored out in %s, couldn't AddArguments",
 116                                   __FUNCTION__);
 117         return lldb::eExpressionSetupError;
 118       }
 119
 120       function_stack_bottom = m_stack_frame_bottom;
 121       function_stack_top = m_stack_frame_top;
 122
 123       IRInterpreter::Interpret(*module, *function, args,
 124                                *m_execution_unit_sp.get(), interpreter_error,
 125                                function_stack_bottom, function_stack_top,
 126                                exe_ctx);
 127
 128       if (!interpreter_error.Success()) {
 129         diagnostic_manager.Printf(eDiagnosticSeverityError,
 130                                   "supposed to interpret, but failed: %s",
 131                                   interpreter_error.AsCString());
 132         return lldb::eExpressionDiscarded;
 133       }
 134     } else {
 135       if (!exe_ctx.HasThreadScope()) {
 136         diagnostic_manager.Printf(eDiagnosticSeverityError,
 137                                   "%s called with no thread selected",
 138                                   __FUNCTION__);
 139         return lldb::eExpressionSetupError;
 140       }
 141
 142       Address wrapper_address(m_jit_start_addr);
 143
 144       std::vector<lldb::addr_t> args;
 145
 146       if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {
 147         diagnostic_manager.Printf(eDiagnosticSeverityError,
 148                                   "errored out in %s, couldn't AddArguments",
 149                                   __FUNCTION__);
 150         return lldb::eExpressionSetupError;
 151       }
 152
 153       lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression(
 154           exe_ctx.GetThreadRef(), wrapper_address, args, options,
 155           shared_ptr_to_me));
 156
 157       StreamString ss;
 158       if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) {
 159         diagnostic_manager.PutString(eDiagnosticSeverityError, ss.GetString());
 160         return lldb::eExpressionSetupError;
 161       }
 162
 163       ThreadPlanCallUserExpression *user_expression_plan =
 164           static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get());
 165
 166       lldb::addr_t function_stack_pointer =
 167           user_expression_plan->GetFunctionStackPointer();
 168
 169       function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize();
 170       function_stack_top = function_stack_pointer;
 171
 172       if (log)
 173         log->Printf(
 174             "-- [UserExpression::Execute] Execution of expression begins --");
 175
 176       if (exe_ctx.GetProcessPtr())
 177         exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
 178
 179       lldb::ExpressionResults execution_result =
 180           exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options,
 181                                                 diagnostic_manager);
 182
 183       if (exe_ctx.GetProcessPtr())
 184         exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
 185
 186       if (log)
 187         log->Printf("-- [UserExpression::Execute] Execution of expression "
 188                     "completed --");
 189
 190       if (execution_result == lldb::eExpressionInterrupted ||
 191           execution_result == lldb::eExpressionHitBreakpoint) {
 192         const char *error_desc = NULL;
 193
 194         if (call_plan_sp) {
 195           lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo();
 196           if (real_stop_info_sp)
 197             error_desc = real_stop_info_sp->GetDescription();
 198         }
 199         if (error_desc)
 200           diagnostic_manager.Printf(eDiagnosticSeverityError,
 201                                     "Execution was interrupted, reason: %s.",
 202                                     error_desc);
 203         else
 204           diagnostic_manager.PutString(eDiagnosticSeverityError,
 205                                        "Execution was interrupted.");
 206
 207         if ((execution_result == lldb::eExpressionInterrupted &&
 208              options.DoesUnwindOnError()) ||
 209             (execution_result == lldb::eExpressionHitBreakpoint &&
 210              options.DoesIgnoreBreakpoints()))
 211           diagnostic_manager.AppendMessageToDiagnostic(
 212               "The process has been returned to the state before expression "
 213               "evaluation.");
 214         else {
 215           if (execution_result == lldb::eExpressionHitBreakpoint)
 216             user_expression_plan->TransferExpressionOwnership();
 217           diagnostic_manager.AppendMessageToDiagnostic(
 218               "The process has been left at the point where it was "
 219               "interrupted, "
 220               "use \"thread return -x\" to return to the state before "
 221               "expression evaluation.");
 222         }
 223
 224         return execution_result;
 225       } else if (execution_result == lldb::eExpressionStoppedForDebug) {
 226         diagnostic_manager.PutString(
 227             eDiagnosticSeverityRemark,
 228             "Execution was halted at the first instruction of the expression "
 229             "function because \"debug\" was requested.\n"
 230             "Use \"thread return -x\" to return to the state before expression "
 231             "evaluation.");
 232         return execution_result;
 233       } else if (execution_result != lldb::eExpressionCompleted) {
 234         diagnostic_manager.Printf(
 235             eDiagnosticSeverityError,
 236             "Couldn't execute function; result was %s",
 237             Process::ExecutionResultAsCString(execution_result));
 238         return execution_result;
 239       }
 240     }
 241
 242     if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result,
 243                              function_stack_bottom, function_stack_top)) {
 244       return lldb::eExpressionCompleted;
 245     } else {
 246       return lldb::eExpressionResultUnavailable;
 247     }
 248   } else {
 249     diagnostic_manager.PutString(
 250         eDiagnosticSeverityError,
 251         "Expression can't be run, because there is no JIT compiled function");
 252     return lldb::eExpressionSetupError;
 253   }
 254 }
 255
 256 bool LLVMUserExpression::FinalizeJITExecution(
 257     DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
 258     lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom,
 259     lldb::addr_t function_stack_top) {
 260   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
 261
 262   if (log)
 263     log->Printf("-- [UserExpression::FinalizeJITExecution] Dematerializing "
 264                 "after execution --");
 265
 266   if (!m_dematerializer_sp) {
 267     diagnostic_manager.Printf(eDiagnosticSeverityError,
 268                               "Couldn't apply expression side effects : no "
 269                               "dematerializer is present");
 270     return false;
 271   }
 272
 273   Status dematerialize_error;
 274
 275   m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom,
 276                                      function_stack_top);
 277
 278   if (!dematerialize_error.Success()) {
 279     diagnostic_manager.Printf(eDiagnosticSeverityError,
 280                               "Couldn't apply expression side effects : %s",
 281                               dematerialize_error.AsCString("unknown error"));
 282     return false;
 283   }
 284
 285   result =
 286       GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope());
 287
 288   if (result)
 289     result->TransferAddress();
 290
 291   m_dematerializer_sp.reset();
 292
 293   return true;
 294 }
 295
 296 bool LLVMUserExpression::PrepareToExecuteJITExpression(
 297     DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
 298     lldb::addr_t &struct_address) {
 299   lldb::TargetSP target;
 300   lldb::ProcessSP process;
 301   lldb::StackFrameSP frame;
 302
 303   if (!LockAndCheckContext(exe_ctx, target, process, frame)) {
 304     diagnostic_manager.PutString(
 305         eDiagnosticSeverityError,
 306         "The context has changed before we could JIT the expression!");
 307     return false;
 308   }
 309
 310   if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) {
 311     if (m_materialized_address == LLDB_INVALID_ADDRESS) {
 312       Status alloc_error;
 313
 314       IRMemoryMap::AllocationPolicy policy =
 315           m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly
 316                           : IRMemoryMap::eAllocationPolicyMirror;
 317
 318       const bool zero_memory = false;
 319
 320       m_materialized_address = m_execution_unit_sp->Malloc(
 321           m_materializer_ap->GetStructByteSize(),
 322           m_materializer_ap->GetStructAlignment(),
 323           lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy,
 324           zero_memory, alloc_error);
 325
 326       if (!alloc_error.Success()) {
 327         diagnostic_manager.Printf(
 328             eDiagnosticSeverityError,
 329             "Couldn't allocate space for materialized struct: %s",
 330             alloc_error.AsCString());
 331         return false;
 332       }
 333     }
 334
 335     struct_address = m_materialized_address;
 336
 337     if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) {
 338       Status alloc_error;
 339
 340       const size_t stack_frame_size = 512 * 1024;
 341
 342       const bool zero_memory = false;
 343
 344       m_stack_frame_bottom = m_execution_unit_sp->Malloc(
 345           stack_frame_size, 8,
 346           lldb::ePermissionsReadable | lldb::ePermissionsWritable,
 347           IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error);
 348
 349       m_stack_frame_top = m_stack_frame_bottom + stack_frame_size;
 350
 351       if (!alloc_error.Success()) {
 352         diagnostic_manager.Printf(
 353             eDiagnosticSeverityError,
 354             "Couldn't allocate space for the stack frame: %s",
 355             alloc_error.AsCString());
 356         return false;
 357       }
 358     }
 359
 360     Status materialize_error;
 361
 362     m_dematerializer_sp = m_materializer_ap->Materialize(
 363         frame, *m_execution_unit_sp, struct_address, materialize_error);
 364
 365     if (!materialize_error.Success()) {
 366       diagnostic_manager.Printf(eDiagnosticSeverityError,
 367                                 "Couldn't materialize: %s",
 368                                 materialize_error.AsCString());
 369       return false;
 370     }
 371   }
 372   return true;
 373 }
 374
 375 lldb::ModuleSP LLVMUserExpression::GetJITModule() {
 376   if (m_execution_unit_sp)
 377     return m_execution_unit_sp->GetJITModule();
 378   return lldb::ModuleSP();
 379 }