1 //===-- UserExpression.cpp ---------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include <stdio.h> 10 #if HAVE_SYS_TYPES_H 11 #include <sys/types.h> 12 #endif 13 14 #include <cstdlib> 15 #include <map> 16 #include <string> 17 18 #include "lldb/Core/Module.h" 19 #include "lldb/Core/StreamFile.h" 20 #include "lldb/Core/ValueObjectConstResult.h" 21 #include "lldb/Expression/DiagnosticManager.h" 22 #include "lldb/Expression/ExpressionVariable.h" 23 #include "lldb/Expression/IRExecutionUnit.h" 24 #include "lldb/Expression/IRInterpreter.h" 25 #include "lldb/Expression/Materializer.h" 26 #include "lldb/Expression/UserExpression.h" 27 #include "lldb/Host/HostInfo.h" 28 #include "lldb/Symbol/Block.h" 29 #include "lldb/Symbol/Function.h" 30 #include "lldb/Symbol/ObjectFile.h" 31 #include "lldb/Symbol/SymbolVendor.h" 32 #include "lldb/Symbol/Type.h" 33 #include "lldb/Symbol/TypeSystem.h" 34 #include "lldb/Symbol/VariableList.h" 35 #include "lldb/Target/ExecutionContext.h" 36 #include "lldb/Target/Process.h" 37 #include "lldb/Target/StackFrame.h" 38 #include "lldb/Target/Target.h" 39 #include "lldb/Target/ThreadPlan.h" 40 #include "lldb/Target/ThreadPlanCallUserExpression.h" 41 #include "lldb/Utility/ConstString.h" 42 #include "lldb/Utility/Log.h" 43 #include "lldb/Utility/StreamString.h" 44 45 using namespace lldb_private; 46 47 UserExpression::UserExpression(ExecutionContextScope &exe_scope, 48 llvm::StringRef expr, llvm::StringRef prefix, 49 lldb::LanguageType language, 50 ResultType desired_type, 51 const EvaluateExpressionOptions &options, 52 ExpressionKind kind) 53 : Expression(exe_scope, kind), m_expr_text(expr), m_expr_prefix(prefix), 54 m_language(language), m_desired_type(desired_type), m_options(options) {} 55 56 UserExpression::~UserExpression() {} 57 58 void UserExpression::InstallContext(ExecutionContext &exe_ctx) { 59 m_jit_process_wp = exe_ctx.GetProcessSP(); 60 61 lldb::StackFrameSP frame_sp = exe_ctx.GetFrameSP(); 62 63 if (frame_sp) 64 m_address = frame_sp->GetFrameCodeAddress(); 65 } 66 67 bool UserExpression::LockAndCheckContext(ExecutionContext &exe_ctx, 68 lldb::TargetSP &target_sp, 69 lldb::ProcessSP &process_sp, 70 lldb::StackFrameSP &frame_sp) { 71 lldb::ProcessSP expected_process_sp = m_jit_process_wp.lock(); 72 process_sp = exe_ctx.GetProcessSP(); 73 74 if (process_sp != expected_process_sp) 75 return false; 76 77 process_sp = exe_ctx.GetProcessSP(); 78 target_sp = exe_ctx.GetTargetSP(); 79 frame_sp = exe_ctx.GetFrameSP(); 80 81 if (m_address.IsValid()) { 82 if (!frame_sp) 83 return false; 84 else 85 return (0 == Address::CompareLoadAddress(m_address, 86 frame_sp->GetFrameCodeAddress(), 87 target_sp.get())); 88 } 89 90 return true; 91 } 92 93 bool UserExpression::MatchesContext(ExecutionContext &exe_ctx) { 94 lldb::TargetSP target_sp; 95 lldb::ProcessSP process_sp; 96 lldb::StackFrameSP frame_sp; 97 98 return LockAndCheckContext(exe_ctx, target_sp, process_sp, frame_sp); 99 } 100 101 lldb::addr_t UserExpression::GetObjectPointer(lldb::StackFrameSP frame_sp, 102 ConstString &object_name, 103 Status &err) { 104 err.Clear(); 105 106 if (!frame_sp) { 107 err.SetErrorStringWithFormat( 108 "Couldn't load '%s' because the context is incomplete", 109 object_name.AsCString()); 110 return LLDB_INVALID_ADDRESS; 111 } 112 113 lldb::VariableSP var_sp; 114 lldb::ValueObjectSP valobj_sp; 115 116 valobj_sp = frame_sp->GetValueForVariableExpressionPath( 117 object_name.AsCString(), lldb::eNoDynamicValues, 118 StackFrame::eExpressionPathOptionCheckPtrVsMember | 119 StackFrame::eExpressionPathOptionsNoFragileObjcIvar | 120 StackFrame::eExpressionPathOptionsNoSyntheticChildren | 121 StackFrame::eExpressionPathOptionsNoSyntheticArrayRange, 122 var_sp, err); 123 124 if (!err.Success() || !valobj_sp.get()) 125 return LLDB_INVALID_ADDRESS; 126 127 lldb::addr_t ret = valobj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS); 128 129 if (ret == LLDB_INVALID_ADDRESS) { 130 err.SetErrorStringWithFormat( 131 "Couldn't load '%s' because its value couldn't be evaluated", 132 object_name.AsCString()); 133 return LLDB_INVALID_ADDRESS; 134 } 135 136 return ret; 137 } 138 139 lldb::ExpressionResults UserExpression::Evaluate( 140 ExecutionContext &exe_ctx, const EvaluateExpressionOptions &options, 141 llvm::StringRef expr, llvm::StringRef prefix, 142 lldb::ValueObjectSP &result_valobj_sp, Status &error, 143 std::string *fixed_expression, lldb::ModuleSP *jit_module_sp_ptr, 144 ValueObject *ctx_obj) { 145 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS | 146 LIBLLDB_LOG_STEP)); 147 148 if (ctx_obj) { 149 static unsigned const ctx_type_mask = 150 lldb::TypeFlags::eTypeIsClass | lldb::TypeFlags::eTypeIsStructUnion; 151 if (!(ctx_obj->GetTypeInfo() & ctx_type_mask)) { 152 LLDB_LOG(log, "== [UserExpression::Evaluate] Passed a context object of " 153 "an invalid type, can't run expressions."); 154 error.SetErrorString("a context object of an invalid type passed"); 155 return lldb::eExpressionSetupError; 156 } 157 } 158 159 lldb_private::ExecutionPolicy execution_policy = options.GetExecutionPolicy(); 160 lldb::LanguageType language = options.GetLanguage(); 161 const ResultType desired_type = options.DoesCoerceToId() 162 ? UserExpression::eResultTypeId 163 : UserExpression::eResultTypeAny; 164 lldb::ExpressionResults execution_results = lldb::eExpressionSetupError; 165 166 Target *target = exe_ctx.GetTargetPtr(); 167 if (!target) { 168 if (log) 169 log->Printf("== [UserExpression::Evaluate] Passed a NULL target, can't " 170 "run expressions."); 171 error.SetErrorString("expression passed a null target"); 172 return lldb::eExpressionSetupError; 173 } 174 175 Process *process = exe_ctx.GetProcessPtr(); 176 177 if (process == nullptr || process->GetState() != lldb::eStateStopped) { 178 if (execution_policy == eExecutionPolicyAlways) { 179 if (log) 180 log->Printf("== [UserExpression::Evaluate] Expression may not run, but " 181 "is not constant =="); 182 183 error.SetErrorString("expression needed to run but couldn't"); 184 185 return execution_results; 186 } 187 } 188 189 if (process == nullptr || !process->CanJIT()) 190 execution_policy = eExecutionPolicyNever; 191 192 // We need to set the expression execution thread here, turns out parse can 193 // call functions in the process of looking up symbols, which will escape the 194 // context set by exe_ctx passed to Execute. 195 lldb::ThreadSP thread_sp = exe_ctx.GetThreadSP(); 196 ThreadList::ExpressionExecutionThreadPusher execution_thread_pusher( 197 thread_sp); 198 199 llvm::StringRef full_prefix; 200 llvm::StringRef option_prefix(options.GetPrefix()); 201 std::string full_prefix_storage; 202 if (!prefix.empty() && !option_prefix.empty()) { 203 full_prefix_storage = prefix; 204 full_prefix_storage.append(option_prefix); 205 full_prefix = full_prefix_storage; 206 } else if (!prefix.empty()) 207 full_prefix = prefix; 208 else 209 full_prefix = option_prefix; 210 211 // If the language was not specified in the expression command, set it to the 212 // language in the target's properties if specified, else default to the 213 // langage for the frame. 214 if (language == lldb::eLanguageTypeUnknown) { 215 if (target->GetLanguage() != lldb::eLanguageTypeUnknown) 216 language = target->GetLanguage(); 217 else if (StackFrame *frame = exe_ctx.GetFramePtr()) 218 language = frame->GetLanguage(); 219 } 220 221 lldb::UserExpressionSP user_expression_sp( 222 target->GetUserExpressionForLanguage(expr, full_prefix, language, 223 desired_type, options, ctx_obj, 224 error)); 225 if (error.Fail()) { 226 if (log) 227 log->Printf("== [UserExpression::Evaluate] Getting expression: %s ==", 228 error.AsCString()); 229 return lldb::eExpressionSetupError; 230 } 231 232 if (log) 233 log->Printf("== [UserExpression::Evaluate] Parsing expression %s ==", 234 expr.str().c_str()); 235 236 const bool keep_expression_in_memory = true; 237 const bool generate_debug_info = options.GetGenerateDebugInfo(); 238 239 if (options.InvokeCancelCallback(lldb::eExpressionEvaluationParse)) { 240 error.SetErrorString("expression interrupted by callback before parse"); 241 result_valobj_sp = ValueObjectConstResult::Create( 242 exe_ctx.GetBestExecutionContextScope(), error); 243 return lldb::eExpressionInterrupted; 244 } 245 246 DiagnosticManager diagnostic_manager; 247 248 bool parse_success = 249 user_expression_sp->Parse(diagnostic_manager, exe_ctx, execution_policy, 250 keep_expression_in_memory, generate_debug_info); 251 252 // Calculate the fixed expression always, since we need it for errors. 253 std::string tmp_fixed_expression; 254 if (fixed_expression == nullptr) 255 fixed_expression = &tmp_fixed_expression; 256 257 const char *fixed_text = user_expression_sp->GetFixedText(); 258 if (fixed_text != nullptr) 259 fixed_expression->append(fixed_text); 260 261 // If there is a fixed expression, try to parse it: 262 if (!parse_success) { 263 execution_results = lldb::eExpressionParseError; 264 if (fixed_expression && !fixed_expression->empty() && 265 options.GetAutoApplyFixIts()) { 266 lldb::UserExpressionSP fixed_expression_sp( 267 target->GetUserExpressionForLanguage(fixed_expression->c_str(), 268 full_prefix, language, 269 desired_type, options, ctx_obj, 270 error)); 271 DiagnosticManager fixed_diagnostic_manager; 272 parse_success = fixed_expression_sp->Parse( 273 fixed_diagnostic_manager, exe_ctx, execution_policy, 274 keep_expression_in_memory, generate_debug_info); 275 if (parse_success) { 276 diagnostic_manager.Clear(); 277 user_expression_sp = fixed_expression_sp; 278 } else { 279 // If the fixed expression failed to parse, don't tell the user about, 280 // that won't help. 281 fixed_expression->clear(); 282 } 283 } 284 285 if (!parse_success) { 286 if (!fixed_expression->empty() && target->GetEnableNotifyAboutFixIts()) { 287 error.SetExpressionErrorWithFormat( 288 execution_results, 289 "expression failed to parse, fixed expression suggested:\n %s", 290 fixed_expression->c_str()); 291 } else { 292 if (!diagnostic_manager.Diagnostics().size()) 293 error.SetExpressionError(execution_results, 294 "expression failed to parse, unknown error"); 295 else 296 error.SetExpressionError(execution_results, 297 diagnostic_manager.GetString().c_str()); 298 } 299 } 300 } 301 302 if (parse_success) { 303 // If a pointer to a lldb::ModuleSP was passed in, return the JIT'ed module 304 // if one was created 305 if (jit_module_sp_ptr) 306 *jit_module_sp_ptr = user_expression_sp->GetJITModule(); 307 308 lldb::ExpressionVariableSP expr_result; 309 310 if (execution_policy == eExecutionPolicyNever && 311 !user_expression_sp->CanInterpret()) { 312 if (log) 313 log->Printf("== [UserExpression::Evaluate] Expression may not run, but " 314 "is not constant =="); 315 316 if (!diagnostic_manager.Diagnostics().size()) 317 error.SetExpressionError(lldb::eExpressionSetupError, 318 "expression needed to run but couldn't"); 319 } else if (execution_policy == eExecutionPolicyTopLevel) { 320 error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric); 321 return lldb::eExpressionCompleted; 322 } else { 323 if (options.InvokeCancelCallback(lldb::eExpressionEvaluationExecution)) { 324 error.SetExpressionError( 325 lldb::eExpressionInterrupted, 326 "expression interrupted by callback before execution"); 327 result_valobj_sp = ValueObjectConstResult::Create( 328 exe_ctx.GetBestExecutionContextScope(), error); 329 return lldb::eExpressionInterrupted; 330 } 331 332 diagnostic_manager.Clear(); 333 334 if (log) 335 log->Printf("== [UserExpression::Evaluate] Executing expression =="); 336 337 execution_results = 338 user_expression_sp->Execute(diagnostic_manager, exe_ctx, options, 339 user_expression_sp, expr_result); 340 341 if (execution_results != lldb::eExpressionCompleted) { 342 if (log) 343 log->Printf("== [UserExpression::Evaluate] Execution completed " 344 "abnormally =="); 345 346 if (!diagnostic_manager.Diagnostics().size()) 347 error.SetExpressionError( 348 execution_results, "expression failed to execute, unknown error"); 349 else 350 error.SetExpressionError(execution_results, 351 diagnostic_manager.GetString().c_str()); 352 } else { 353 if (expr_result) { 354 result_valobj_sp = expr_result->GetValueObject(); 355 356 if (log) 357 log->Printf("== [UserExpression::Evaluate] Execution completed " 358 "normally with result %s ==", 359 result_valobj_sp->GetValueAsCString()); 360 } else { 361 if (log) 362 log->Printf("== [UserExpression::Evaluate] Execution completed " 363 "normally with no result =="); 364 365 error.SetError(UserExpression::kNoResult, lldb::eErrorTypeGeneric); 366 } 367 } 368 } 369 } 370 371 if (options.InvokeCancelCallback(lldb::eExpressionEvaluationComplete)) { 372 error.SetExpressionError( 373 lldb::eExpressionInterrupted, 374 "expression interrupted by callback after complete"); 375 return lldb::eExpressionInterrupted; 376 } 377 378 if (result_valobj_sp.get() == nullptr) { 379 result_valobj_sp = ValueObjectConstResult::Create( 380 exe_ctx.GetBestExecutionContextScope(), error); 381 } 382 383 return execution_results; 384 } 385 386 lldb::ExpressionResults 387 UserExpression::Execute(DiagnosticManager &diagnostic_manager, 388 ExecutionContext &exe_ctx, 389 const EvaluateExpressionOptions &options, 390 lldb::UserExpressionSP &shared_ptr_to_me, 391 lldb::ExpressionVariableSP &result_var) { 392 lldb::ExpressionResults expr_result = DoExecute( 393 diagnostic_manager, exe_ctx, options, shared_ptr_to_me, result_var); 394 Target *target = exe_ctx.GetTargetPtr(); 395 if (options.GetResultIsInternal() && result_var && target) { 396 target->GetPersistentExpressionStateForLanguage(m_language) 397 ->RemovePersistentVariable(result_var); 398 } 399 return expr_result; 400 } 401