tools/lli/lli.cpp

   1 //===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
   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 // This utility provides a simple wrapper around the LLVM Execution Engines,
  11 // which allow the direct execution of LLVM programs through a Just-In-Time
  12 // compiler, or through an interpreter if no JIT is available for this platform.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/LLVMContext.h"
  17 #include "llvm/Module.h"
  18 #include "llvm/Type.h"
  19 #include "llvm/ADT/Triple.h"
  20 #include "llvm/Bitcode/ReaderWriter.h"
  21 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
  22 #include "llvm/ExecutionEngine/GenericValue.h"
  23 #include "llvm/ExecutionEngine/Interpreter.h"
  24 #include "llvm/ExecutionEngine/JIT.h"
  25 #include "llvm/ExecutionEngine/JITEventListener.h"
  26 #include "llvm/ExecutionEngine/MCJIT.h"
  27 #include "llvm/Support/CommandLine.h"
  28 #include "llvm/Support/IRReader.h"
  29 #include "llvm/Support/ManagedStatic.h"
  30 #include "llvm/Support/MemoryBuffer.h"
  31 #include "llvm/Support/PluginLoader.h"
  32 #include "llvm/Support/PrettyStackTrace.h"
  33 #include "llvm/Support/raw_ostream.h"
  34 #include "llvm/Support/Process.h"
  35 #include "llvm/Support/Signals.h"
  36 #include "llvm/Target/TargetSelect.h"
  37 #include <cerrno>
  38
  39 #ifdef __CYGWIN__
  40 #include <cygwin/version.h>
  41 #if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
  42 #define DO_NOTHING_ATEXIT 1
  43 #endif
  44 #endif
  45
  46 using namespace llvm;
  47
  48 namespace {
  49   cl::opt<std::string>
  50   InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
  51
  52   cl::list<std::string>
  53   InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
  54
  55   cl::opt<bool> ForceInterpreter("force-interpreter",
  56                                  cl::desc("Force interpretation: disable JIT"),
  57                                  cl::init(false));
  58
  59   cl::opt<bool> UseMCJIT(
  60     "use-mcjit", cl::desc("Enable use of the MC-based JIT (if available)"),
  61     cl::init(false));
  62
  63   // Determine optimization level.
  64   cl::opt<char>
  65   OptLevel("O",
  66            cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
  67                     "(default = '-O2')"),
  68            cl::Prefix,
  69            cl::ZeroOrMore,
  70            cl::init(' '));
  71
  72   cl::opt<std::string>
  73   TargetTriple("mtriple", cl::desc("Override target triple for module"));
  74
  75   cl::opt<std::string>
  76   MArch("march",
  77         cl::desc("Architecture to generate assembly for (see --version)"));
  78
  79   cl::opt<std::string>
  80   MCPU("mcpu",
  81        cl::desc("Target a specific cpu type (-mcpu=help for details)"),
  82        cl::value_desc("cpu-name"),
  83        cl::init(""));
  84
  85   cl::list<std::string>
  86   MAttrs("mattr",
  87          cl::CommaSeparated,
  88          cl::desc("Target specific attributes (-mattr=help for details)"),
  89          cl::value_desc("a1,+a2,-a3,..."));
  90
  91   cl::opt<std::string>
  92   EntryFunc("entry-function",
  93             cl::desc("Specify the entry function (default = 'main') "
  94                      "of the executable"),
  95             cl::value_desc("function"),
  96             cl::init("main"));
  97
  98   cl::opt<std::string>
  99   FakeArgv0("fake-argv0",
 100             cl::desc("Override the 'argv[0]' value passed into the executing"
 101                      " program"), cl::value_desc("executable"));
 102
 103   cl::opt<bool>
 104   DisableCoreFiles("disable-core-files", cl::Hidden,
 105                    cl::desc("Disable emission of core files if possible"));
 106
 107   cl::opt<bool>
 108   NoLazyCompilation("disable-lazy-compilation",
 109                   cl::desc("Disable JIT lazy compilation"),
 110                   cl::init(false));
 111 }
 112
 113 static ExecutionEngine *EE = 0;
 114
 115 static void do_shutdown() {
 116   // Cygwin-1.5 invokes DLL's dtors before atexit handler.
 117 #ifndef DO_NOTHING_ATEXIT
 118   delete EE;
 119   llvm_shutdown();
 120 #endif
 121 }
 122
 123 //===----------------------------------------------------------------------===//
 124 // main Driver function
 125 //
 126 int main(int argc, char **argv, char * const *envp) {
 127   sys::PrintStackTraceOnErrorSignal();
 128   PrettyStackTraceProgram X(argc, argv);
 129
 130   LLVMContext &Context = getGlobalContext();
 131   atexit(do_shutdown);  // Call llvm_shutdown() on exit.
 132
 133   // If we have a native target, initialize it to ensure it is linked in and
 134   // usable by the JIT.
 135   InitializeNativeTarget();
 136   InitializeNativeTargetAsmPrinter();
 137
 138   cl::ParseCommandLineOptions(argc, argv,
 139                               "llvm interpreter & dynamic compiler\n");
 140
 141   // If the user doesn't want core files, disable them.
 142   if (DisableCoreFiles)
 143     sys::Process::PreventCoreFiles();
 144
 145   // Load the bitcode...
 146   SMDiagnostic Err;
 147   Module *Mod = ParseIRFile(InputFile, Err, Context);
 148   if (!Mod) {
 149     Err.Print(argv[0], errs());
 150     return 1;
 151   }
 152
 153   // If not jitting lazily, load the whole bitcode file eagerly too.
 154   std::string ErrorMsg;
 155   if (NoLazyCompilation) {
 156     if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
 157       errs() << argv[0] << ": bitcode didn't read correctly.\n";
 158       errs() << "Reason: " << ErrorMsg << "\n";
 159       exit(1);
 160     }
 161   }
 162
 163   EngineBuilder builder(Mod);
 164   builder.setMArch(MArch);
 165   builder.setMCPU(MCPU);
 166   builder.setMAttrs(MAttrs);
 167   builder.setErrorStr(&ErrorMsg);
 168   builder.setEngineKind(ForceInterpreter
 169                         ? EngineKind::Interpreter
 170                         : EngineKind::JIT);
 171
 172   // If we are supposed to override the target triple, do so now.
 173   if (!TargetTriple.empty())
 174     Mod->setTargetTriple(Triple::normalize(TargetTriple));
 175
 176   // Enable MCJIT, if desired.
 177   if (UseMCJIT)
 178     builder.setUseMCJIT(true);
 179
 180   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 181   switch (OptLevel) {
 182   default:
 183     errs() << argv[0] << ": invalid optimization level.\n";
 184     return 1;
 185   case ' ': break;
 186   case '0': OLvl = CodeGenOpt::None; break;
 187   case '1': OLvl = CodeGenOpt::Less; break;
 188   case '2': OLvl = CodeGenOpt::Default; break;
 189   case '3': OLvl = CodeGenOpt::Aggressive; break;
 190   }
 191   builder.setOptLevel(OLvl);
 192
 193   EE = builder.create();
 194   if (!EE) {
 195     if (!ErrorMsg.empty())
 196       errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
 197     else
 198       errs() << argv[0] << ": unknown error creating EE!\n";
 199     exit(1);
 200   }
 201
 202   EE->RegisterJITEventListener(createOProfileJITEventListener());
 203
 204   EE->DisableLazyCompilation(NoLazyCompilation);
 205
 206   // If the user specifically requested an argv[0] to pass into the program,
 207   // do it now.
 208   if (!FakeArgv0.empty()) {
 209     InputFile = FakeArgv0;
 210   } else {
 211     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 212     // might confuse the program.
 213     if (StringRef(InputFile).endswith(".bc"))
 214       InputFile.erase(InputFile.length() - 3);
 215   }
 216
 217   // Add the module's name to the start of the vector of arguments to main().
 218   InputArgv.insert(InputArgv.begin(), InputFile);
 219
 220   // Call the main function from M as if its signature were:
 221   //   int main (int argc, char **argv, const char **envp)
 222   // using the contents of Args to determine argc & argv, and the contents of
 223   // EnvVars to determine envp.
 224   //
 225   Function *EntryFn = Mod->getFunction(EntryFunc);
 226   if (!EntryFn) {
 227     errs() << '\'' << EntryFunc << "\' function not found in module.\n";
 228     return -1;
 229   }
 230
 231   // If the program doesn't explicitly call exit, we will need the Exit
 232   // function later on to make an explicit call, so get the function now.
 233   Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
 234                                                     Type::getInt32Ty(Context),
 235                                                     NULL);
 236
 237   // Reset errno to zero on entry to main.
 238   errno = 0;
 239
 240   // Run static constructors.
 241   EE->runStaticConstructorsDestructors(false);
 242
 243   if (NoLazyCompilation) {
 244     for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
 245       Function *Fn = &*I;
 246       if (Fn != EntryFn && !Fn->isDeclaration())
 247         EE->getPointerToFunction(Fn);
 248     }
 249   }
 250
 251   // Run main.
 252   int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 253
 254   // Run static destructors.
 255   EE->runStaticConstructorsDestructors(true);
 256
 257   // If the program didn't call exit explicitly, we should call it now.
 258   // This ensures that any atexit handlers get called correctly.
 259   if (Function *ExitF = dyn_cast<Function>(Exit)) {
 260     std::vector<GenericValue> Args;
 261     GenericValue ResultGV;
 262     ResultGV.IntVal = APInt(32, Result);
 263     Args.push_back(ResultGV);
 264     EE->runFunction(ExitF, Args);
 265     errs() << "ERROR: exit(" << Result << ") returned!\n";
 266     abort();
 267   } else {
 268     errs() << "ERROR: exit defined with wrong prototype!\n";
 269     abort();
 270   }
 271 }