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