source/Expression/UserExpression.cpp

   1 //===-- UserExpression.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 #include <stdio.h>
  11 #if HAVE_SYS_TYPES_H
  12 #include <sys/types.h>
  13 #endif
  14
  15 #include <cstdlib>
  16 #include <map>
  17 #include <string>
  18
  19 #include "Plugins/ExpressionParser/Clang/ClangPersistentVariables.h"
  20 #include "lldb/Core/ConstString.h"
  21 #include "lldb/Core/Log.h"
  22 #include "lldb/Core/Module.h"
  23 #include "lldb/Core/StreamFile.h"
  24 #include "lldb/Core/StreamString.h"
  25 #include "lldb/Core/ValueObjectConstResult.h"
  26 #include "lldb/Expression/DiagnosticManager.h"
  27 #include "lldb/Expression/ExpressionSourceCode.h"
  28 #include "lldb/Expression/IRExecutionUnit.h"
  29 #include "lldb/Expression/IRInterpreter.h"
  30 #include "lldb/Expression/Materializer.h"
  31 #include "lldb/Expression/UserExpression.h"
  32 #include "lldb/Host/HostInfo.h"
  33 #include "lldb/Symbol/Block.h"
  34 #include "lldb/Symbol/Function.h"
  35 #include "lldb/Symbol/ObjectFile.h"
  36 #include "lldb/Symbol/SymbolVendor.h"
  37 #include "lldb/Symbol/Type.h"
  38 #include "lldb/Symbol/TypeSystem.h"
  39 #include "lldb/Symbol/VariableList.h"
  40 #include "lldb/Target/ExecutionContext.h"
  41 #include "lldb/Target/Process.h"
  42 #include "lldb/Target/StackFrame.h"
  43 #include "lldb/Target/Target.h"
  44 #include "lldb/Target/ThreadPlan.h"
  45 #include "lldb/Target/ThreadPlanCallUserExpression.h"
  46
  47 using namespace lldb_private;
  48
  49 UserExpression::UserExpression(ExecutionContextScope &exe_scope,
  50                                llvm::StringRef expr, llvm::StringRef prefix,
  51                                lldb::LanguageType language,
  52                                ResultType desired_type,
  53                                const EvaluateExpressionOptions &options)
  54     : Expression(exe_scope), m_expr_text(expr), m_expr_prefix(prefix),
  55       m_language(language), m_desired_type(desired_type), m_options(options) {}
  56
  57 UserExpression::~UserExpression() {}
  58
  59 void UserExpression::InstallContext(ExecutionContext &exe_ctx) {
  60   m_jit_process_wp = exe_ctx.GetProcessSP();
  61
  62   lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP();
  63
  64   if (frame_sp)
  65     m_address = frame_sp->GetFrameCodeAddress();
  66 }
  67
  68 bool UserExpression::LockAndCheckContext(ExecutionContext &exe_ctx,
  69                                          lldb::TargetSP &target_sp,
  70                                          lldb::ProcessSP &process_sp,
  71                                          lldb::StackFrameSP &frame_sp) {
  72   lldb::ProcessSP expected_process_sp = m_jit_process_wp.lock();
  73   process_sp = exe_ctx.GetProcessSP();
  74
  75   if (process_sp != expected_process_sp)
  76     return false;
  77
  78   process_sp = exe_ctx.GetProcessSP();
  79   target_sp = exe_ctx.GetTargetSP();
  80   frame_sp = exe_ctx.GetFrameSP();
  81
  82   if (m_address.IsValid()) {
  83     if (!frame_sp)
  84       return false;
  85     else
  86       return (0 == Address::CompareLoadAddress(m_address,
  87                                                frame_sp->GetFrameCodeAddress(),
  88                                                target_sp.get()));
  89   }
  90
  91   return true;
  92 }
  93
  94 bool UserExpression::MatchesContext(ExecutionContext &exe_ctx) {
  95   lldb::TargetSP target_sp;
  96   lldb::ProcessSP process_sp;
  97   lldb::StackFrameSP frame_sp;
  98
  99   return LockAndCheckContext(exe_ctx, target_sp, process_sp, frame_sp);
 100 }
 101
 102 lldb::addr_t UserExpression::GetObjectPointer(lldb::StackFrameSP frame_sp,
 103                                               ConstString &object_name,
 104                                               Error &err) {
 105   err.Clear();
 106
 107   if (!frame_sp) {
 108     err.SetErrorStringWithFormat(
 109         "Couldn't load '%s' because the context is incomplete",
 110         object_name.AsCString());
 111     return LLDB_INVALID_ADDRESS;
 112   }
 113
 114   lldb::VariableSP var_sp;
 115   lldb::ValueObjectSP valobj_sp;
 116
 117   valobj_sp = frame_sp->GetValueForVariableExpressionPath(
 118       object_name.AsCString(), lldb::eNoDynamicValues,
 119       StackFrame::eExpressionPathOptionCheckPtrVsMember |
 120           StackFrame::eExpressionPathOptionsNoFragileObjcIvar |
 121           StackFrame::eExpressionPathOptionsNoSyntheticChildren |
 122           StackFrame::eExpressionPathOptionsNoSyntheticArrayRange,
 123       var_sp, err);
 124
 125   if (!err.Success() || !valobj_sp.get())
 126     return LLDB_INVALID_ADDRESS;
 127
 128   lldb::addr_t ret = valobj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
 129
 130   if (ret == LLDB_INVALID_ADDRESS) {
 131     err.SetErrorStringWithFormat(
 132         "Couldn't load '%s' because its value couldn't be evaluated",
 133         object_name.AsCString());
 134     return LLDB_INVALID_ADDRESS;
 135   }
 136
 137   return ret;
 138 }
 139
 140 lldb::ExpressionResults UserExpression::Evaluate(
 141     ExecutionContext &exe_ctx, const EvaluateExpressionOptions &options,
 142     llvm::StringRef expr, llvm::StringRef prefix,
 143     lldb::ValueObjectSP &result_valobj_sp, Error &error, uint32_t line_offset,
 144     std::string *fixed_expression, lldb::ModuleSP *jit_module_sp_ptr) {
 145   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
 146                                                   LIBLLDB_LOG_STEP));
 147
 148   lldb_private::ExecutionPolicy execution_policy = options.GetExecutionPolicy();
 149   lldb::LanguageType language = options.GetLanguage();
 150   const ResultType desired_type = options.DoesCoerceToId()
 151                                       ? UserExpression::eResultTypeId
 152                                       : UserExpression::eResultTypeAny;
 153   lldb::ExpressionResults execution_results = lldb::eExpressionSetupError;
 154
 155   Target *target = exe_ctx.GetTargetPtr();
 156   if (!target) {
 157     if (log)
 158       log->Printf("== [UserExpression::Evaluate] Passed a NULL target, can't "
 159                   "run expressions.");
 160     error.SetErrorString("expression passed a null target");
 161     return lldb::eExpressionSetupError;
 162   }
 163
 164   Process *process = exe_ctx.GetProcessPtr();
 165
 166   if (process == NULL || process->GetState() != lldb::eStateStopped) {
 167     if (execution_policy == eExecutionPolicyAlways) {
 168       if (log)
 169         log->Printf("== [UserExpression::Evaluate] Expression may not run, but "
 170                     "is not constant ==");
 171
 172       error.SetErrorString("expression needed to run but couldn't");
 173
 174       return execution_results;
 175     }
 176   }
 177
 178   if (process == NULL || !process->CanJIT())
 179     execution_policy = eExecutionPolicyNever;
 180
 181   // We need to set the expression execution thread here, turns out parse can
 182   // call functions in the process of
 183   // looking up symbols, which will escape the context set by exe_ctx passed to
 184   // Execute.
 185   lldb::ThreadSP thread_sp = exe_ctx.GetThreadSP();
 186   ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
 187       thread_sp);
 188
 189   llvm::StringRef full_prefix;
 190   llvm::StringRef option_prefix(options.GetPrefix());
 191   std::string full_prefix_storage;
 192   if (!prefix.empty() && !option_prefix.empty()) {
 193     full_prefix_storage = prefix;
 194     full_prefix_storage.append(option_prefix);
 195     full_prefix = full_prefix_storage;
 196   } else if (!prefix.empty())
 197     full_prefix = prefix;
 198   else
 199     full_prefix = option_prefix;
 200
 201   // If the language was not specified in the expression command,
 202   // set it to the language in the target's properties if
 203   // specified, else default to the langage for the frame.
 204   if (language == lldb::eLanguageTypeUnknown) {
 205     if (target->GetLanguage() != lldb::eLanguageTypeUnknown)
 206       language = target->GetLanguage();
 207     else if (StackFrame *frame = exe_ctx.GetFramePtr())
 208       language = frame->GetLanguage();
 209   }
 210
 211   lldb::UserExpressionSP user_expression_sp(
 212       target->GetUserExpressionForLanguage(expr, full_prefix, language,
 213                                            desired_type, options, error));
 214   if (error.Fail()) {
 215     if (log)
 216       log->Printf("== [UserExpression::Evaluate] Getting expression: %s ==",
 217                   error.AsCString());
 218     return lldb::eExpressionSetupError;
 219   }
 220
 221   if (log)
 222     log->Printf("== [UserExpression::Evaluate] Parsing expression %s ==",
 223                 expr.str().c_str());
 224
 225   const bool keep_expression_in_memory = true;
 226   const bool generate_debug_info = options.GetGenerateDebugInfo();
 227
 228   if (options.InvokeCancelCallback(lldb::eExpressionEvaluationParse)) {
 229     error.SetErrorString("expression interrupted by callback before parse");
 230     result_valobj_sp = ValueObjectConstResult::Create(
 231         exe_ctx.GetBestExecutionContextScope(), error);
 232     return lldb::eExpressionInterrupted;
 233   }
 234
 235   DiagnosticManager diagnostic_manager;
 236
 237   bool parse_success =
 238       user_expression_sp->Parse(diagnostic_manager, exe_ctx, execution_policy,
 239                                 keep_expression_in_memory, generate_debug_info);
 240
 241   // Calculate the fixed expression always, since we need it for errors.
 242   std::string tmp_fixed_expression;
 243   if (fixed_expression == nullptr)
 244     fixed_expression = &tmp_fixed_expression;
 245
 246   const char *fixed_text = user_expression_sp->GetFixedText();
 247   if (fixed_text != nullptr)
 248     fixed_expression->append(fixed_text);
 249
 250   // If there is a fixed expression, try to parse it:
 251   if (!parse_success) {
 252     execution_results = lldb::eExpressionParseError;
 253     if (fixed_expression && !fixed_expression->empty() &&
 254         options.GetAutoApplyFixIts()) {
 255       lldb::UserExpressionSP fixed_expression_sp(
 256           target->GetUserExpressionForLanguage(fixed_expression->c_str(),
 257                                                full_prefix, language,
 258                                                desired_type, options, error));
 259       DiagnosticManager fixed_diagnostic_manager;
 260       parse_success = fixed_expression_sp->Parse(
 261           fixed_diagnostic_manager, exe_ctx, execution_policy,
 262           keep_expression_in_memory, generate_debug_info);
 263       if (parse_success) {
 264         diagnostic_manager.Clear();
 265         user_expression_sp = fixed_expression_sp;
 266       } else {
 267         // If the fixed expression failed to parse, don't tell the user about,
 268         // that won't help.
 269         fixed_expression->clear();
 270       }
 271     }
 272
 273     if (!parse_success) {
 274       if (!fixed_expression->empty() && target->GetEnableNotifyAboutFixIts()) {
 275         error.SetExpressionErrorWithFormat(
 276             execution_results,
 277             "expression failed to parse, fixed expression suggested:\n  %s",
 278             fixed_expression->c_str());
 279       } else {
 280         if (!diagnostic_manager.Diagnostics().size())
 281           error.SetExpressionError(execution_results,
 282                                    "expression failed to parse, unknown error");
 283         else
 284           error.SetExpressionError(execution_results,
 285                                    diagnostic_manager.GetString().c_str());
 286       }
 287     }
 288   }
 289
 290   if (parse_success) {
 291     // If a pointer to a lldb::ModuleSP was passed in, return the JIT'ed module
 292     // if one was created
 293     if (jit_module_sp_ptr)
 294       *jit_module_sp_ptr = user_expression_sp->GetJITModule();
 295
 296     lldb::ExpressionVariableSP expr_result;
 297
 298     if (execution_policy == eExecutionPolicyNever &&
 299         !user_expression_sp->CanInterpret()) {
 300       if (log)
 301         log->Printf("== [UserExpression::Evaluate] Expression may not run, but "
 302                     "is not constant ==");
 303
 304       if (!diagnostic_manager.Diagnostics().size())
 305         error.SetExpressionError(lldb::eExpressionSetupError,
 306                                  "expression needed to run but couldn't");
 307     } else if (execution_policy == eExecutionPolicyTopLevel) {
 308       error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric);
 309       return lldb::eExpressionCompleted;
 310     } else {
 311       if (options.InvokeCancelCallback(lldb::eExpressionEvaluationExecution)) {
 312         error.SetExpressionError(
 313             lldb::eExpressionInterrupted,
 314             "expression interrupted by callback before execution");
 315         result_valobj_sp = ValueObjectConstResult::Create(
 316             exe_ctx.GetBestExecutionContextScope(), error);
 317         return lldb::eExpressionInterrupted;
 318       }
 319
 320       diagnostic_manager.Clear();
 321
 322       if (log)
 323         log->Printf("== [UserExpression::Evaluate] Executing expression ==");
 324
 325       execution_results =
 326           user_expression_sp->Execute(diagnostic_manager, exe_ctx, options,
 327                                       user_expression_sp, expr_result);
 328
 329       if (execution_results != lldb::eExpressionCompleted) {
 330         if (log)
 331           log->Printf("== [UserExpression::Evaluate] Execution completed "
 332                       "abnormally ==");
 333
 334         if (!diagnostic_manager.Diagnostics().size())
 335           error.SetExpressionError(
 336               execution_results, "expression failed to execute, unknown error");
 337         else
 338           error.SetExpressionError(execution_results,
 339                                    diagnostic_manager.GetString().c_str());
 340       } else {
 341         if (expr_result) {
 342           result_valobj_sp = expr_result->GetValueObject();
 343
 344           if (log)
 345             log->Printf("== [UserExpression::Evaluate] Execution completed "
 346                         "normally with result %s ==",
 347                         result_valobj_sp->GetValueAsCString());
 348         } else {
 349           if (log)
 350             log->Printf("== [UserExpression::Evaluate] Execution completed "
 351                         "normally with no result ==");
 352
 353           error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric);
 354         }
 355       }
 356     }
 357   }
 358
 359   if (options.InvokeCancelCallback(lldb::eExpressionEvaluationComplete)) {
 360     error.SetExpressionError(
 361         lldb::eExpressionInterrupted,
 362         "expression interrupted by callback after complete");
 363     return lldb::eExpressionInterrupted;
 364   }
 365
 366   if (result_valobj_sp.get() == NULL) {
 367     result_valobj_sp = ValueObjectConstResult::Create(
 368         exe_ctx.GetBestExecutionContextScope(), error);
 369   }
 370
 371   return execution_results;
 372 }
 373
 374 lldb::ExpressionResults
 375 UserExpression::Execute(DiagnosticManager &diagnostic_manager,
 376                         ExecutionContext &exe_ctx,
 377                         const EvaluateExpressionOptions &options,
 378                         lldb::UserExpressionSP &shared_ptr_to_me,
 379                         lldb::ExpressionVariableSP &result_var) {
 380   lldb::ExpressionResults expr_result = DoExecute(
 381       diagnostic_manager, exe_ctx, options, shared_ptr_to_me, result_var);
 382   Target *target = exe_ctx.GetTargetPtr();
 383   if (options.GetResultIsInternal() && result_var && target) {
 384     target->GetPersistentExpressionStateForLanguage(m_language)
 385         ->RemovePersistentVariable(result_var);
 386   }
 387   return expr_result;
 388 }