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
 137   cl::ParseCommandLineOptions(argc, argv,
 138                               "llvm interpreter & dynamic compiler\n");
 139
 140   // If the user doesn't want core files, disable them.
 141   if (DisableCoreFiles)
 142     sys::Process::PreventCoreFiles();
 143
 144   // Load the bitcode...
 145   SMDiagnostic Err;
 146   Module *Mod = ParseIRFile(InputFile, Err, Context);
 147   if (!Mod) {
 148     Err.Print(argv[0], errs());
 149     return 1;
 150   }
 151
 152   // If not jitting lazily, load the whole bitcode file eagerly too.
 153   std::string ErrorMsg;
 154   if (NoLazyCompilation) {
 155     if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
 156       errs() << argv[0] << ": bitcode didn't read correctly.\n";
 157       errs() << "Reason: " << ErrorMsg << "\n";
 158       exit(1);
 159     }
 160   }
 161
 162   EngineBuilder builder(Mod);
 163   builder.setMArch(MArch);
 164   builder.setMCPU(MCPU);
 165   builder.setMAttrs(MAttrs);
 166   builder.setErrorStr(&ErrorMsg);
 167   builder.setEngineKind(ForceInterpreter
 168                         ? EngineKind::Interpreter
 169                         : EngineKind::JIT);
 170
 171   // If we are supposed to override the target triple, do so now.
 172   if (!TargetTriple.empty())
 173     Mod->setTargetTriple(Triple::normalize(TargetTriple));
 174
 175   // Enable MCJIT, if desired.
 176   if (UseMCJIT)
 177     builder.setUseMCJIT(true);
 178
 179   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 180   switch (OptLevel) {
 181   default:
 182     errs() << argv[0] << ": invalid optimization level.\n";
 183     return 1;
 184   case ' ': break;
 185   case '0': OLvl = CodeGenOpt::None; break;
 186   case '1': OLvl = CodeGenOpt::Less; break;
 187   case '2': OLvl = CodeGenOpt::Default; break;
 188   case '3': OLvl = CodeGenOpt::Aggressive; break;
 189   }
 190   builder.setOptLevel(OLvl);
 191
 192   EE = builder.create();
 193   if (!EE) {
 194     if (!ErrorMsg.empty())
 195       errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
 196     else
 197       errs() << argv[0] << ": unknown error creating EE!\n";
 198     exit(1);
 199   }
 200
 201   EE->RegisterJITEventListener(createOProfileJITEventListener());
 202
 203   EE->DisableLazyCompilation(NoLazyCompilation);
 204
 205   // If the user specifically requested an argv[0] to pass into the program,
 206   // do it now.
 207   if (!FakeArgv0.empty()) {
 208     InputFile = FakeArgv0;
 209   } else {
 210     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 211     // might confuse the program.
 212     if (StringRef(InputFile).endswith(".bc"))
 213       InputFile.erase(InputFile.length() - 3);
 214   }
 215
 216   // Add the module's name to the start of the vector of arguments to main().
 217   InputArgv.insert(InputArgv.begin(), InputFile);
 218
 219   // Call the main function from M as if its signature were:
 220   //   int main (int argc, char **argv, const char **envp)
 221   // using the contents of Args to determine argc & argv, and the contents of
 222   // EnvVars to determine envp.
 223   //
 224   Function *EntryFn = Mod->getFunction(EntryFunc);
 225   if (!EntryFn) {
 226     errs() << '\'' << EntryFunc << "\' function not found in module.\n";
 227     return -1;
 228   }
 229
 230   // If the program doesn't explicitly call exit, we will need the Exit
 231   // function later on to make an explicit call, so get the function now.
 232   Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
 233                                                     Type::getInt32Ty(Context),
 234                                                     NULL);
 235
 236   // Reset errno to zero on entry to main.
 237   errno = 0;
 238
 239   // Run static constructors.
 240   EE->runStaticConstructorsDestructors(false);
 241
 242   if (NoLazyCompilation) {
 243     for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
 244       Function *Fn = &*I;
 245       if (Fn != EntryFn && !Fn->isDeclaration())
 246         EE->getPointerToFunction(Fn);
 247     }
 248   }
 249
 250   // Run main.
 251   int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 252
 253   // Run static destructors.
 254   EE->runStaticConstructorsDestructors(true);
 255
 256   // If the program didn't call exit explicitly, we should call it now.
 257   // This ensures that any atexit handlers get called correctly.
 258   if (Function *ExitF = dyn_cast<Function>(Exit)) {
 259     std::vector<GenericValue> Args;
 260     GenericValue ResultGV;
 261     ResultGV.IntVal = APInt(32, Result);
 262     Args.push_back(ResultGV);
 263     EE->runFunction(ExitF, Args);
 264     errs() << "ERROR: exit(" << Result << ") returned!\n";
 265     abort();
 266   } else {
 267     errs() << "ERROR: exit defined with wrong prototype!\n";
 268     abort();
 269   }
 270 }