contrib/llvm/tools/lldb/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/Module.h"
  21 #include "lldb/Core/StreamFile.h"
  22 #include "lldb/Core/ValueObjectConstResult.h"
  23 #include "lldb/Expression/DiagnosticManager.h"
  24 #include "lldb/Expression/ExpressionSourceCode.h"
  25 #include "lldb/Expression/IRExecutionUnit.h"
  26 #include "lldb/Expression/IRInterpreter.h"
  27 #include "lldb/Expression/Materializer.h"
  28 #include "lldb/Expression/UserExpression.h"
  29 #include "lldb/Host/HostInfo.h"
  30 #include "lldb/Symbol/Block.h"
  31 #include "lldb/Symbol/Function.h"
  32 #include "lldb/Symbol/ObjectFile.h"
  33 #include "lldb/Symbol/SymbolVendor.h"
  34 #include "lldb/Symbol/Type.h"
  35 #include "lldb/Symbol/TypeSystem.h"
  36 #include "lldb/Symbol/VariableList.h"
  37 #include "lldb/Target/ExecutionContext.h"
  38 #include "lldb/Target/Process.h"
  39 #include "lldb/Target/StackFrame.h"
  40 #include "lldb/Target/Target.h"
  41 #include "lldb/Target/ThreadPlan.h"
  42 #include "lldb/Target/ThreadPlanCallUserExpression.h"
  43 #include "lldb/Utility/ConstString.h"
  44 #include "lldb/Utility/Log.h"
  45 #include "lldb/Utility/StreamString.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                                               Status &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, Status &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 looking up symbols, which will escape the
 183   // context set by exe_ctx passed to Execute.
 184   lldb::ThreadSP thread_sp = exe_ctx.GetThreadSP();
 185   ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher(
 186       thread_sp);
 187
 188   llvm::StringRef full_prefix;
 189   llvm::StringRef option_prefix(options.GetPrefix());
 190   std::string full_prefix_storage;
 191   if (!prefix.empty() && !option_prefix.empty()) {
 192     full_prefix_storage = prefix;
 193     full_prefix_storage.append(option_prefix);
 194     full_prefix = full_prefix_storage;
 195   } else if (!prefix.empty())
 196     full_prefix = prefix;
 197   else
 198     full_prefix = option_prefix;
 199
 200   // If the language was not specified in the expression command, set it to the
 201   // language in the target's properties if specified, else default to the
 202   // langage for the frame.
 203   if (language == lldb::eLanguageTypeUnknown) {
 204     if (target->GetLanguage() != lldb::eLanguageTypeUnknown)
 205       language = target->GetLanguage();
 206     else if (StackFrame *frame = exe_ctx.GetFramePtr())
 207       language = frame->GetLanguage();
 208   }
 209
 210   lldb::UserExpressionSP user_expression_sp(
 211       target->GetUserExpressionForLanguage(expr, full_prefix, language,
 212                                            desired_type, options, error));
 213   if (error.Fail()) {
 214     if (log)
 215       log->Printf("== [UserExpression::Evaluate] Getting expression: %s ==",
 216                   error.AsCString());
 217     return lldb::eExpressionSetupError;
 218   }
 219
 220   if (log)
 221     log->Printf("== [UserExpression::Evaluate] Parsing expression %s ==",
 222                 expr.str().c_str());
 223
 224   const bool keep_expression_in_memory = true;
 225   const bool generate_debug_info = options.GetGenerateDebugInfo();
 226
 227   if (options.InvokeCancelCallback(lldb::eExpressionEvaluationParse)) {
 228     error.SetErrorString("expression interrupted by callback before parse");
 229     result_valobj_sp = ValueObjectConstResult::Create(
 230         exe_ctx.GetBestExecutionContextScope(), error);
 231     return lldb::eExpressionInterrupted;
 232   }
 233
 234   DiagnosticManager diagnostic_manager;
 235
 236   bool parse_success =
 237       user_expression_sp->Parse(diagnostic_manager, exe_ctx, execution_policy,
 238                                 keep_expression_in_memory, generate_debug_info);
 239
 240   // Calculate the fixed expression always, since we need it for errors.
 241   std::string tmp_fixed_expression;
 242   if (fixed_expression == nullptr)
 243     fixed_expression = &tmp_fixed_expression;
 244
 245   const char *fixed_text = user_expression_sp->GetFixedText();
 246   if (fixed_text != nullptr)
 247     fixed_expression->append(fixed_text);
 248
 249   // If there is a fixed expression, try to parse it:
 250   if (!parse_success) {
 251     execution_results = lldb::eExpressionParseError;
 252     if (fixed_expression && !fixed_expression->empty() &&
 253         options.GetAutoApplyFixIts()) {
 254       lldb::UserExpressionSP fixed_expression_sp(
 255           target->GetUserExpressionForLanguage(fixed_expression->c_str(),
 256                                                full_prefix, language,
 257                                                desired_type, options, error));
 258       DiagnosticManager fixed_diagnostic_manager;
 259       parse_success = fixed_expression_sp->Parse(
 260           fixed_diagnostic_manager, exe_ctx, execution_policy,
 261           keep_expression_in_memory, generate_debug_info);
 262       if (parse_success) {
 263         diagnostic_manager.Clear();
 264         user_expression_sp = fixed_expression_sp;
 265       } else {
 266         // If the fixed expression failed to parse, don't tell the user about,
 267         // that won't help.
 268         fixed_expression->clear();
 269       }
 270     }
 271
 272     if (!parse_success) {
 273       if (!fixed_expression->empty() && target->GetEnableNotifyAboutFixIts()) {
 274         error.SetExpressionErrorWithFormat(
 275             execution_results,
 276             "expression failed to parse, fixed expression suggested:\n  %s",
 277             fixed_expression->c_str());
 278       } else {
 279         if (!diagnostic_manager.Diagnostics().size())
 280           error.SetExpressionError(execution_results,
 281                                    "expression failed to parse, unknown error");
 282         else
 283           error.SetExpressionError(execution_results,
 284                                    diagnostic_manager.GetString().c_str());
 285       }
 286     }
 287   }
 288
 289   if (parse_success) {
 290     // If a pointer to a lldb::ModuleSP was passed in, return the JIT'ed module
 291     // if one was created
 292     if (jit_module_sp_ptr)
 293       *jit_module_sp_ptr = user_expression_sp->GetJITModule();
 294
 295     lldb::ExpressionVariableSP expr_result;
 296
 297     if (execution_policy == eExecutionPolicyNever &&
 298         !user_expression_sp->CanInterpret()) {
 299       if (log)
 300         log->Printf("== [UserExpression::Evaluate] Expression may not run, but "
 301                     "is not constant ==");
 302
 303       if (!diagnostic_manager.Diagnostics().size())
 304         error.SetExpressionError(lldb::eExpressionSetupError,
 305                                  "expression needed to run but couldn't");
 306     } else if (execution_policy == eExecutionPolicyTopLevel) {
 307       error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric);
 308       return lldb::eExpressionCompleted;
 309     } else {
 310       if (options.InvokeCancelCallback(lldb::eExpressionEvaluationExecution)) {
 311         error.SetExpressionError(
 312             lldb::eExpressionInterrupted,
 313             "expression interrupted by callback before execution");
 314         result_valobj_sp = ValueObjectConstResult::Create(
 315             exe_ctx.GetBestExecutionContextScope(), error);
 316         return lldb::eExpressionInterrupted;
 317       }
 318
 319       diagnostic_manager.Clear();
 320
 321       if (log)
 322         log->Printf("== [UserExpression::Evaluate] Executing expression ==");
 323
 324       execution_results =
 325           user_expression_sp->Execute(diagnostic_manager, exe_ctx, options,
 326                                       user_expression_sp, expr_result);
 327
 328       if (execution_results != lldb::eExpressionCompleted) {
 329         if (log)
 330           log->Printf("== [UserExpression::Evaluate] Execution completed "
 331                       "abnormally ==");
 332
 333         if (!diagnostic_manager.Diagnostics().size())
 334           error.SetExpressionError(
 335               execution_results, "expression failed to execute, unknown error");
 336         else
 337           error.SetExpressionError(execution_results,
 338                                    diagnostic_manager.GetString().c_str());
 339       } else {
 340         if (expr_result) {
 341           result_valobj_sp = expr_result->GetValueObject();
 342
 343           if (log)
 344             log->Printf("== [UserExpression::Evaluate] Execution completed "
 345                         "normally with result %s ==",
 346                         result_valobj_sp->GetValueAsCString());
 347         } else {
 348           if (log)
 349             log->Printf("== [UserExpression::Evaluate] Execution completed "
 350                         "normally with no result ==");
 351
 352           error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric);
 353         }
 354       }
 355     }
 356   }
 357
 358   if (options.InvokeCancelCallback(lldb::eExpressionEvaluationComplete)) {
 359     error.SetExpressionError(
 360         lldb::eExpressionInterrupted,
 361         "expression interrupted by callback after complete");
 362     return lldb::eExpressionInterrupted;
 363   }
 364
 365   if (result_valobj_sp.get() == NULL) {
 366     result_valobj_sp = ValueObjectConstResult::Create(
 367         exe_ctx.GetBestExecutionContextScope(), error);
 368   }
 369
 370   return execution_results;
 371 }
 372
 373 lldb::ExpressionResults
 374 UserExpression::Execute(DiagnosticManager &diagnostic_manager,
 375                         ExecutionContext &exe_ctx,
 376                         const EvaluateExpressionOptions &options,
 377                         lldb::UserExpressionSP &shared_ptr_to_me,
 378                         lldb::ExpressionVariableSP &result_var) {
 379   lldb::ExpressionResults expr_result = DoExecute(
 380       diagnostic_manager, exe_ctx, options, shared_ptr_to_me, result_var);
 381   Target *target = exe_ctx.GetTargetPtr();
 382   if (options.GetResultIsInternal() && result_var && target) {
 383     target->GetPersistentExpressionStateForLanguage(m_language)
 384         ->RemovePersistentVariable(result_var);
 385   }
 386   return expr_result;
 387 }