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/Support/CommandLine.h"
  27 #include "llvm/Support/ManagedStatic.h"
  28 #include "llvm/Support/MemoryBuffer.h"
  29 #include "llvm/Support/PluginLoader.h"
  30 #include "llvm/Support/PrettyStackTrace.h"
  31 #include "llvm/Support/raw_ostream.h"
  32 #include "llvm/System/Process.h"
  33 #include "llvm/System/Signals.h"
  34 #include "llvm/Target/TargetSelect.h"
  35 #include <cerrno>
  36
  37 #ifdef __CYGWIN__
  38 #include <cygwin/version.h>
  39 #if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
  40 #define DO_NOTHING_ATEXIT 1
  41 #endif
  42 #endif
  43
  44 using namespace llvm;
  45
  46 namespace {
  47   cl::opt<std::string>
  48   InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
  49
  50   cl::list<std::string>
  51   InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
  52
  53   cl::opt<bool> ForceInterpreter("force-interpreter",
  54                                  cl::desc("Force interpretation: disable JIT"),
  55                                  cl::init(false));
  56
  57   // Determine optimization level.
  58   cl::opt<char>
  59   OptLevel("O",
  60            cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
  61                     "(default = '-O2')"),
  62            cl::Prefix,
  63            cl::ZeroOrMore,
  64            cl::init(' '));
  65
  66   cl::opt<std::string>
  67   TargetTriple("mtriple", cl::desc("Override target triple for module"));
  68
  69   cl::opt<std::string>
  70   MArch("march",
  71         cl::desc("Architecture to generate assembly for (see --version)"));
  72
  73   cl::opt<std::string>
  74   MCPU("mcpu",
  75        cl::desc("Target a specific cpu type (-mcpu=help for details)"),
  76        cl::value_desc("cpu-name"),
  77        cl::init(""));
  78
  79   cl::list<std::string>
  80   MAttrs("mattr",
  81          cl::CommaSeparated,
  82          cl::desc("Target specific attributes (-mattr=help for details)"),
  83          cl::value_desc("a1,+a2,-a3,..."));
  84
  85   cl::opt<std::string>
  86   EntryFunc("entry-function",
  87             cl::desc("Specify the entry function (default = 'main') "
  88                      "of the executable"),
  89             cl::value_desc("function"),
  90             cl::init("main"));
  91
  92   cl::opt<std::string>
  93   FakeArgv0("fake-argv0",
  94             cl::desc("Override the 'argv[0]' value passed into the executing"
  95                      " program"), cl::value_desc("executable"));
  96
  97   cl::opt<bool>
  98   DisableCoreFiles("disable-core-files", cl::Hidden,
  99                    cl::desc("Disable emission of core files if possible"));
 100
 101   cl::opt<bool>
 102   NoLazyCompilation("disable-lazy-compilation",
 103                   cl::desc("Disable JIT lazy compilation"),
 104                   cl::init(false));
 105 }
 106
 107 static ExecutionEngine *EE = 0;
 108
 109 static void do_shutdown() {
 110   // Cygwin-1.5 invokes DLL's dtors before atexit handler.
 111 #ifndef DO_NOTHING_ATEXIT
 112   delete EE;
 113   llvm_shutdown();
 114 #endif
 115 }
 116
 117 //===----------------------------------------------------------------------===//
 118 // main Driver function
 119 //
 120 int main(int argc, char **argv, char * const *envp) {
 121   sys::PrintStackTraceOnErrorSignal();
 122   PrettyStackTraceProgram X(argc, argv);
 123
 124   LLVMContext &Context = getGlobalContext();
 125   atexit(do_shutdown);  // Call llvm_shutdown() on exit.
 126
 127   // If we have a native target, initialize it to ensure it is linked in and
 128   // usable by the JIT.
 129   InitializeNativeTarget();
 130
 131   cl::ParseCommandLineOptions(argc, argv,
 132                               "llvm interpreter & dynamic compiler\n");
 133
 134   // If the user doesn't want core files, disable them.
 135   if (DisableCoreFiles)
 136     sys::Process::PreventCoreFiles();
 137
 138   // Load the bitcode...
 139   std::string ErrorMsg;
 140   Module *Mod = NULL;
 141   if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFile,&ErrorMsg)){
 142     Mod = getLazyBitcodeModule(Buffer, Context, &ErrorMsg);
 143     if (!Mod) delete Buffer;
 144   }
 145
 146   if (!Mod) {
 147     errs() << argv[0] << ": error loading program '" << InputFile << "': "
 148            << ErrorMsg << "\n";
 149     exit(1);
 150   }
 151
 152   // If not jitting lazily, load the whole bitcode file eagerly too.
 153   if (NoLazyCompilation) {
 154     if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
 155       errs() << argv[0] << ": bitcode didn't read correctly.\n";
 156       errs() << "Reason: " << ErrorMsg << "\n";
 157       exit(1);
 158     }
 159   }
 160
 161   EngineBuilder builder(Mod);
 162   builder.setMArch(MArch);
 163   builder.setMCPU(MCPU);
 164   builder.setMAttrs(MAttrs);
 165   builder.setErrorStr(&ErrorMsg);
 166   builder.setEngineKind(ForceInterpreter
 167                         ? EngineKind::Interpreter
 168                         : EngineKind::JIT);
 169
 170   // If we are supposed to override the target triple, do so now.
 171   if (!TargetTriple.empty())
 172     Mod->setTargetTriple(Triple::normalize(TargetTriple));
 173
 174   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 175   switch (OptLevel) {
 176   default:
 177     errs() << argv[0] << ": invalid optimization level.\n";
 178     return 1;
 179   case ' ': break;
 180   case '0': OLvl = CodeGenOpt::None; break;
 181   case '1': OLvl = CodeGenOpt::Less; break;
 182   case '2': OLvl = CodeGenOpt::Default; break;
 183   case '3': OLvl = CodeGenOpt::Aggressive; break;
 184   }
 185   builder.setOptLevel(OLvl);
 186
 187   EE = builder.create();
 188   if (!EE) {
 189     if (!ErrorMsg.empty())
 190       errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
 191     else
 192       errs() << argv[0] << ": unknown error creating EE!\n";
 193     exit(1);
 194   }
 195
 196   EE->RegisterJITEventListener(createOProfileJITEventListener());
 197
 198   EE->DisableLazyCompilation(NoLazyCompilation);
 199
 200   // If the user specifically requested an argv[0] to pass into the program,
 201   // do it now.
 202   if (!FakeArgv0.empty()) {
 203     InputFile = FakeArgv0;
 204   } else {
 205     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 206     // might confuse the program.
 207     if (StringRef(InputFile).endswith(".bc"))
 208       InputFile.erase(InputFile.length() - 3);
 209   }
 210
 211   // Add the module's name to the start of the vector of arguments to main().
 212   InputArgv.insert(InputArgv.begin(), InputFile);
 213
 214   // Call the main function from M as if its signature were:
 215   //   int main (int argc, char **argv, const char **envp)
 216   // using the contents of Args to determine argc & argv, and the contents of
 217   // EnvVars to determine envp.
 218   //
 219   Function *EntryFn = Mod->getFunction(EntryFunc);
 220   if (!EntryFn) {
 221     errs() << '\'' << EntryFunc << "\' function not found in module.\n";
 222     return -1;
 223   }
 224
 225   // If the program doesn't explicitly call exit, we will need the Exit
 226   // function later on to make an explicit call, so get the function now.
 227   Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
 228                                                     Type::getInt32Ty(Context),
 229                                                     NULL);
 230
 231   // Reset errno to zero on entry to main.
 232   errno = 0;
 233
 234   // Run static constructors.
 235   EE->runStaticConstructorsDestructors(false);
 236
 237   if (NoLazyCompilation) {
 238     for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
 239       Function *Fn = &*I;
 240       if (Fn != EntryFn && !Fn->isDeclaration())
 241         EE->getPointerToFunction(Fn);
 242     }
 243   }
 244
 245   // Run main.
 246   int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 247
 248   // Run static destructors.
 249   EE->runStaticConstructorsDestructors(true);
 250
 251   // If the program didn't call exit explicitly, we should call it now.
 252   // This ensures that any atexit handlers get called correctly.
 253   if (Function *ExitF = dyn_cast<Function>(Exit)) {
 254     std::vector<GenericValue> Args;
 255     GenericValue ResultGV;
 256     ResultGV.IntVal = APInt(32, Result);
 257     Args.push_back(ResultGV);
 258     EE->runFunction(ExitF, Args);
 259     errs() << "ERROR: exit(" << Result << ") returned!\n";
 260     abort();
 261   } else {
 262     errs() << "ERROR: exit defined with wrong prototype!\n";
 263     abort();
 264   }
 265 }