1 //===- ExecutionDriver.cpp - Allow execution of LLVM program --------------===// 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 // This file contains code used to execute the program utilizing one of the 10 // various ways of running LLVM bitcode. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "BugDriver.h" 15 #include "ToolRunner.h" 16 #include "llvm/Support/CommandLine.h" 17 #include "llvm/Support/Debug.h" 18 #include "llvm/Support/FileUtilities.h" 19 #include "llvm/Support/Program.h" 20 #include "llvm/Support/SystemUtils.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <fstream> 23 24 using namespace llvm; 25 26 namespace { 27 // OutputType - Allow the user to specify the way code should be run, to test 28 // for miscompilation. 29 // 30 enum OutputType { 31 AutoPick, 32 RunLLI, 33 RunJIT, 34 RunLLC, 35 RunLLCIA, 36 LLC_Safe, 37 CompileCustom, 38 Custom 39 }; 40 41 cl::opt<double> AbsTolerance("abs-tolerance", 42 cl::desc("Absolute error tolerated"), 43 cl::init(0.0)); 44 cl::opt<double> RelTolerance("rel-tolerance", 45 cl::desc("Relative error tolerated"), 46 cl::init(0.0)); 47 48 cl::opt<OutputType> InterpreterSel( 49 cl::desc("Specify the \"test\" i.e. suspect back-end:"), 50 cl::values(clEnumValN(AutoPick, "auto", "Use best guess"), 51 clEnumValN(RunLLI, "run-int", "Execute with the interpreter"), 52 clEnumValN(RunJIT, "run-jit", "Execute with JIT"), 53 clEnumValN(RunLLC, "run-llc", "Compile with LLC"), 54 clEnumValN(RunLLCIA, "run-llc-ia", 55 "Compile with LLC with integrated assembler"), 56 clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"), 57 clEnumValN(CompileCustom, "compile-custom", 58 "Use -compile-command to define a command to " 59 "compile the bitcode. Useful to avoid linking."), 60 clEnumValN(Custom, "run-custom", 61 "Use -exec-command to define a command to execute " 62 "the bitcode. Useful for cross-compilation.")), 63 cl::init(AutoPick)); 64 65 cl::opt<OutputType> SafeInterpreterSel( 66 cl::desc("Specify \"safe\" i.e. known-good backend:"), 67 cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"), 68 clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"), 69 clEnumValN(Custom, "safe-run-custom", 70 "Use -exec-command to define a command to execute " 71 "the bitcode. Useful for cross-compilation.")), 72 cl::init(AutoPick)); 73 74 cl::opt<std::string> SafeInterpreterPath( 75 "safe-path", cl::desc("Specify the path to the \"safe\" backend program"), 76 cl::init("")); 77 78 cl::opt<bool> AppendProgramExitCode( 79 "append-exit-code", 80 cl::desc("Append the exit code to the output so it gets diff'd too"), 81 cl::init(false)); 82 83 cl::opt<std::string> 84 InputFile("input", cl::init("/dev/null"), 85 cl::desc("Filename to pipe in as stdin (default: /dev/null)")); 86 87 cl::list<std::string> 88 AdditionalSOs("additional-so", cl::desc("Additional shared objects to load " 89 "into executing programs")); 90 91 cl::list<std::string> AdditionalLinkerArgs( 92 "Xlinker", cl::desc("Additional arguments to pass to the linker")); 93 94 cl::opt<std::string> CustomCompileCommand( 95 "compile-command", cl::init("llc"), 96 cl::desc("Command to compile the bitcode (use with -compile-custom) " 97 "(default: llc)")); 98 99 cl::opt<std::string> CustomExecCommand( 100 "exec-command", cl::init("simulate"), 101 cl::desc("Command to execute the bitcode (use with -run-custom) " 102 "(default: simulate)")); 103 } 104 105 namespace llvm { 106 // Anything specified after the --args option are taken as arguments to the 107 // program being debugged. 108 cl::list<std::string> InputArgv("args", cl::Positional, 109 cl::desc("<program arguments>..."), 110 cl::ZeroOrMore, cl::PositionalEatsArgs); 111 112 cl::opt<std::string> 113 OutputPrefix("output-prefix", cl::init("bugpoint"), 114 cl::desc("Prefix to use for outputs (default: 'bugpoint')")); 115 } 116 117 namespace { 118 cl::list<std::string> ToolArgv("tool-args", cl::Positional, 119 cl::desc("<tool arguments>..."), cl::ZeroOrMore, 120 cl::PositionalEatsArgs); 121 122 cl::list<std::string> SafeToolArgv("safe-tool-args", cl::Positional, 123 cl::desc("<safe-tool arguments>..."), 124 cl::ZeroOrMore, cl::PositionalEatsArgs); 125 126 cl::opt<std::string> CCBinary("gcc", cl::init(""), 127 cl::desc("The gcc binary to use.")); 128 129 cl::list<std::string> CCToolArgv("gcc-tool-args", cl::Positional, 130 cl::desc("<gcc-tool arguments>..."), 131 cl::ZeroOrMore, cl::PositionalEatsArgs); 132 } 133 134 //===----------------------------------------------------------------------===// 135 // BugDriver method implementation 136 // 137 138 /// initializeExecutionEnvironment - This method is used to set up the 139 /// environment for executing LLVM programs. 140 /// 141 Error BugDriver::initializeExecutionEnvironment() { 142 outs() << "Initializing execution environment: "; 143 144 // Create an instance of the AbstractInterpreter interface as specified on 145 // the command line 146 SafeInterpreter = nullptr; 147 std::string Message; 148 149 if (CCBinary.empty()) { 150 if (ErrorOr<std::string> ClangPath = 151 FindProgramByName("clang", getToolName(), &AbsTolerance)) 152 CCBinary = *ClangPath; 153 else 154 CCBinary = "gcc"; 155 } 156 157 switch (InterpreterSel) { 158 case AutoPick: 159 if (!Interpreter) { 160 InterpreterSel = RunJIT; 161 Interpreter = 162 AbstractInterpreter::createJIT(getToolName(), Message, &ToolArgv); 163 } 164 if (!Interpreter) { 165 InterpreterSel = RunLLC; 166 Interpreter = AbstractInterpreter::createLLC( 167 getToolName(), Message, CCBinary, &ToolArgv, &CCToolArgv); 168 } 169 if (!Interpreter) { 170 InterpreterSel = RunLLI; 171 Interpreter = 172 AbstractInterpreter::createLLI(getToolName(), Message, &ToolArgv); 173 } 174 if (!Interpreter) { 175 InterpreterSel = AutoPick; 176 Message = "Sorry, I can't automatically select an interpreter!\n"; 177 } 178 break; 179 case RunLLI: 180 Interpreter = 181 AbstractInterpreter::createLLI(getToolName(), Message, &ToolArgv); 182 break; 183 case RunLLC: 184 case RunLLCIA: 185 case LLC_Safe: 186 Interpreter = AbstractInterpreter::createLLC( 187 getToolName(), Message, CCBinary, &ToolArgv, &CCToolArgv, 188 InterpreterSel == RunLLCIA); 189 break; 190 case RunJIT: 191 Interpreter = 192 AbstractInterpreter::createJIT(getToolName(), Message, &ToolArgv); 193 break; 194 case CompileCustom: 195 Interpreter = AbstractInterpreter::createCustomCompiler( 196 getToolName(), Message, CustomCompileCommand); 197 break; 198 case Custom: 199 Interpreter = AbstractInterpreter::createCustomExecutor( 200 getToolName(), Message, CustomExecCommand); 201 break; 202 } 203 if (!Interpreter) 204 errs() << Message; 205 else // Display informational messages on stdout instead of stderr 206 outs() << Message; 207 208 std::string Path = SafeInterpreterPath; 209 if (Path.empty()) 210 Path = getToolName(); 211 std::vector<std::string> SafeToolArgs = SafeToolArgv; 212 switch (SafeInterpreterSel) { 213 case AutoPick: 214 // In "llc-safe" mode, default to using LLC as the "safe" backend. 215 if (!SafeInterpreter && InterpreterSel == LLC_Safe) { 216 SafeInterpreterSel = RunLLC; 217 SafeToolArgs.push_back("--relocation-model=pic"); 218 SafeInterpreter = AbstractInterpreter::createLLC( 219 Path.c_str(), Message, CCBinary, &SafeToolArgs, &CCToolArgv); 220 } 221 222 if (!SafeInterpreter && InterpreterSel != RunLLC && 223 InterpreterSel != RunJIT) { 224 SafeInterpreterSel = RunLLC; 225 SafeToolArgs.push_back("--relocation-model=pic"); 226 SafeInterpreter = AbstractInterpreter::createLLC( 227 Path.c_str(), Message, CCBinary, &SafeToolArgs, &CCToolArgv); 228 } 229 if (!SafeInterpreter) { 230 SafeInterpreterSel = AutoPick; 231 Message = "Sorry, I can't automatically select a safe interpreter!\n"; 232 } 233 break; 234 case RunLLC: 235 case RunLLCIA: 236 SafeToolArgs.push_back("--relocation-model=pic"); 237 SafeInterpreter = AbstractInterpreter::createLLC( 238 Path.c_str(), Message, CCBinary, &SafeToolArgs, &CCToolArgv, 239 SafeInterpreterSel == RunLLCIA); 240 break; 241 case Custom: 242 SafeInterpreter = AbstractInterpreter::createCustomExecutor( 243 getToolName(), Message, CustomExecCommand); 244 break; 245 default: 246 Message = "Sorry, this back-end is not supported by bugpoint as the " 247 "\"safe\" backend right now!\n"; 248 break; 249 } 250 if (!SafeInterpreter) { 251 outs() << Message << "\nExiting.\n"; 252 exit(1); 253 } 254 255 cc = CC::create(getToolName(), Message, CCBinary, &CCToolArgv); 256 if (!cc) { 257 outs() << Message << "\nExiting.\n"; 258 exit(1); 259 } 260 261 // If there was an error creating the selected interpreter, quit with error. 262 if (Interpreter == nullptr) 263 return make_error<StringError>("Failed to init execution environment", 264 inconvertibleErrorCode()); 265 return Error::success(); 266 } 267 268 /// Try to compile the specified module, returning false and setting Error if an 269 /// error occurs. This is used for code generation crash testing. 270 Error BugDriver::compileProgram(Module &M) const { 271 // Emit the program to a bitcode file... 272 auto Temp = 273 sys::fs::TempFile::create(OutputPrefix + "-test-program-%%%%%%%.bc"); 274 if (!Temp) { 275 errs() << ToolName 276 << ": Error making unique filename: " << toString(Temp.takeError()) 277 << "\n"; 278 exit(1); 279 } 280 DiscardTemp Discard{*Temp}; 281 if (writeProgramToFile(Temp->FD, M)) { 282 errs() << ToolName << ": Error emitting bitcode to file '" << Temp->TmpName 283 << "'!\n"; 284 exit(1); 285 } 286 287 // Actually compile the program! 288 return Interpreter->compileProgram(Temp->TmpName, Timeout, MemoryLimit); 289 } 290 291 /// This method runs "Program", capturing the output of the program to a file, 292 /// returning the filename of the file. A recommended filename may be 293 /// optionally specified. 294 Expected<std::string> BugDriver::executeProgram(const Module &Program, 295 std::string OutputFile, 296 std::string BitcodeFile, 297 const std::string &SharedObj, 298 AbstractInterpreter *AI) const { 299 if (!AI) 300 AI = Interpreter; 301 assert(AI && "Interpreter should have been created already!"); 302 bool CreatedBitcode = false; 303 if (BitcodeFile.empty()) { 304 // Emit the program to a bitcode file... 305 SmallString<128> UniqueFilename; 306 int UniqueFD; 307 std::error_code EC = sys::fs::createUniqueFile( 308 OutputPrefix + "-test-program-%%%%%%%.bc", UniqueFD, UniqueFilename); 309 if (EC) { 310 errs() << ToolName << ": Error making unique filename: " << EC.message() 311 << "!\n"; 312 exit(1); 313 } 314 BitcodeFile = std::string(UniqueFilename.str()); 315 316 if (writeProgramToFile(BitcodeFile, UniqueFD, Program)) { 317 errs() << ToolName << ": Error emitting bitcode to file '" << BitcodeFile 318 << "'!\n"; 319 exit(1); 320 } 321 CreatedBitcode = true; 322 } 323 324 // Remove the temporary bitcode file when we are done. 325 std::string BitcodePath(BitcodeFile); 326 FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode && !SaveTemps); 327 328 if (OutputFile.empty()) 329 OutputFile = OutputPrefix + "-execution-output-%%%%%%%"; 330 331 // Check to see if this is a valid output filename... 332 SmallString<128> UniqueFile; 333 std::error_code EC = sys::fs::createUniqueFile(OutputFile, UniqueFile); 334 if (EC) { 335 errs() << ToolName << ": Error making unique filename: " << EC.message() 336 << "\n"; 337 exit(1); 338 } 339 OutputFile = std::string(UniqueFile.str()); 340 341 // Figure out which shared objects to run, if any. 342 std::vector<std::string> SharedObjs(AdditionalSOs); 343 if (!SharedObj.empty()) 344 SharedObjs.push_back(SharedObj); 345 346 Expected<int> RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile, 347 OutputFile, AdditionalLinkerArgs, 348 SharedObjs, Timeout, MemoryLimit); 349 if (Error E = RetVal.takeError()) 350 return std::move(E); 351 352 if (*RetVal == -1) { 353 errs() << "<timeout>"; 354 static bool FirstTimeout = true; 355 if (FirstTimeout) { 356 outs() 357 << "\n" 358 "*** Program execution timed out! This mechanism is designed to " 359 "handle\n" 360 " programs stuck in infinite loops gracefully. The -timeout " 361 "option\n" 362 " can be used to change the timeout threshold or disable it " 363 "completely\n" 364 " (with -timeout=0). This message is only displayed once.\n"; 365 FirstTimeout = false; 366 } 367 } 368 369 if (AppendProgramExitCode) { 370 std::ofstream outFile(OutputFile.c_str(), std::ios_base::app); 371 outFile << "exit " << *RetVal << '\n'; 372 outFile.close(); 373 } 374 375 // Return the filename we captured the output to. 376 return OutputFile; 377 } 378 379 /// Used to create reference output with the "safe" backend, if reference output 380 /// is not provided. 381 Expected<std::string> 382 BugDriver::executeProgramSafely(const Module &Program, 383 const std::string &OutputFile) const { 384 return executeProgram(Program, OutputFile, "", "", SafeInterpreter); 385 } 386 387 Expected<std::string> 388 BugDriver::compileSharedObject(const std::string &BitcodeFile) { 389 assert(Interpreter && "Interpreter should have been created already!"); 390 std::string OutputFile; 391 392 // Using the known-good backend. 393 Expected<CC::FileType> FT = 394 SafeInterpreter->OutputCode(BitcodeFile, OutputFile); 395 if (Error E = FT.takeError()) 396 return std::move(E); 397 398 std::string SharedObjectFile; 399 if (Error E = cc->MakeSharedObject(OutputFile, *FT, SharedObjectFile, 400 AdditionalLinkerArgs)) 401 return std::move(E); 402 403 // Remove the intermediate C file 404 sys::fs::remove(OutputFile); 405 406 return SharedObjectFile; 407 } 408 409 /// Calls compileProgram and then records the output into ReferenceOutputFile. 410 /// Returns true if reference file created, false otherwise. Note: 411 /// initializeExecutionEnvironment should be called BEFORE this function. 412 Error BugDriver::createReferenceFile(Module &M, const std::string &Filename) { 413 if (Error E = compileProgram(*Program)) 414 return E; 415 416 Expected<std::string> Result = executeProgramSafely(*Program, Filename); 417 if (Error E = Result.takeError()) { 418 if (Interpreter != SafeInterpreter) { 419 E = joinErrors( 420 std::move(E), 421 make_error<StringError>( 422 "*** There is a bug running the \"safe\" backend. Either" 423 " debug it (for example with the -run-jit bugpoint option," 424 " if JIT is being used as the \"safe\" backend), or fix the" 425 " error some other way.\n", 426 inconvertibleErrorCode())); 427 } 428 return E; 429 } 430 ReferenceOutputFile = *Result; 431 outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n"; 432 return Error::success(); 433 } 434 435 /// This method executes the specified module and diffs the output against the 436 /// file specified by ReferenceOutputFile. If the output is different, 1 is 437 /// returned. If there is a problem with the code generator (e.g., llc 438 /// crashes), this will set ErrMsg. 439 Expected<bool> BugDriver::diffProgram(const Module &Program, 440 const std::string &BitcodeFile, 441 const std::string &SharedObject, 442 bool RemoveBitcode) const { 443 // Execute the program, generating an output file... 444 Expected<std::string> Output = 445 executeProgram(Program, "", BitcodeFile, SharedObject, nullptr); 446 if (Error E = Output.takeError()) 447 return std::move(E); 448 449 std::string Error; 450 bool FilesDifferent = false; 451 if (int Diff = DiffFilesWithTolerance(ReferenceOutputFile, *Output, 452 AbsTolerance, RelTolerance, &Error)) { 453 if (Diff == 2) { 454 errs() << "While diffing output: " << Error << '\n'; 455 exit(1); 456 } 457 FilesDifferent = true; 458 } else { 459 // Remove the generated output if there are no differences. 460 sys::fs::remove(*Output); 461 } 462 463 // Remove the bitcode file if we are supposed to. 464 if (RemoveBitcode) 465 sys::fs::remove(BitcodeFile); 466 return FilesDifferent; 467 } 468 469 bool BugDriver::isExecutingJIT() { return InterpreterSel == RunJIT; } 470