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/ModuleProvider.h"
  19 #include "llvm/Type.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/System/Process.h"
  32 #include "llvm/System/Signals.h"
  33 #include "llvm/Target/TargetSelect.h"
  34 #include <iostream>
  35 #include <cerrno>
  36 using namespace llvm;
  37
  38 namespace {
  39   cl::opt<std::string>
  40   InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
  41
  42   cl::list<std::string>
  43   InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
  44
  45   cl::opt<bool> ForceInterpreter("force-interpreter",
  46                                  cl::desc("Force interpretation: disable JIT"),
  47                                  cl::init(false));
  48
  49   // Determine optimization level.
  50   cl::opt<char>
  51   OptLevel("O",
  52            cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
  53                     "(default = '-O2')"),
  54            cl::Prefix,
  55            cl::ZeroOrMore,
  56            cl::init(' '));
  57
  58   cl::opt<std::string>
  59   TargetTriple("mtriple", cl::desc("Override target triple for module"));
  60
  61   cl::opt<std::string>
  62   EntryFunc("entry-function",
  63             cl::desc("Specify the entry function (default = 'main') "
  64                      "of the executable"),
  65             cl::value_desc("function"),
  66             cl::init("main"));
  67
  68   cl::opt<std::string>
  69   FakeArgv0("fake-argv0",
  70             cl::desc("Override the 'argv[0]' value passed into the executing"
  71                      " program"), cl::value_desc("executable"));
  72
  73   cl::opt<bool>
  74   DisableCoreFiles("disable-core-files", cl::Hidden,
  75                    cl::desc("Disable emission of core files if possible"));
  76
  77   cl::opt<bool>
  78   NoLazyCompilation("disable-lazy-compilation",
  79                   cl::desc("Disable JIT lazy compilation"),
  80                   cl::init(false));
  81 }
  82
  83 static ExecutionEngine *EE = 0;
  84
  85 static void do_shutdown() {
  86   delete EE;
  87   llvm_shutdown();
  88 }
  89
  90 //===----------------------------------------------------------------------===//
  91 // main Driver function
  92 //
  93 int main(int argc, char **argv, char * const *envp) {
  94   sys::PrintStackTraceOnErrorSignal();
  95   PrettyStackTraceProgram X(argc, argv);
  96
  97   LLVMContext Context;
  98   atexit(do_shutdown);  // Call llvm_shutdown() on exit.
  99   cl::ParseCommandLineOptions(argc, argv,
 100                               "llvm interpreter & dynamic compiler\n");
 101
 102   // If the user doesn't want core files, disable them.
 103   if (DisableCoreFiles)
 104     sys::Process::PreventCoreFiles();
 105
 106   // Load the bitcode...
 107   std::string ErrorMsg;
 108   ModuleProvider *MP = NULL;
 109   if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFile,&ErrorMsg)){
 110     MP = getBitcodeModuleProvider(Buffer, Context, &ErrorMsg);
 111     if (!MP) delete Buffer;
 112   }
 113
 114   if (!MP) {
 115     errs() << argv[0] << ": error loading program '" << InputFile << "': "
 116            << ErrorMsg << "\n";
 117     exit(1);
 118   }
 119
 120   // Get the module as the MP could go away once EE takes over.
 121   Module *Mod = NoLazyCompilation
 122     ? MP->materializeModule(&ErrorMsg) : MP->getModule();
 123   if (!Mod) {
 124     errs() << argv[0] << ": bitcode didn't read correctly.\n";
 125     errs() << "Reason: " << ErrorMsg << "\n";
 126     exit(1);
 127   }
 128
 129   // If we are supposed to override the target triple, do so now.
 130   if (!TargetTriple.empty())
 131     Mod->setTargetTriple(TargetTriple);
 132
 133   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 134   switch (OptLevel) {
 135   default:
 136     errs() << argv[0] << ": invalid optimization level.\n";
 137     return 1;
 138   case ' ': break;
 139   case '0': OLvl = CodeGenOpt::None; break;
 140   case '1':
 141   case '2': OLvl = CodeGenOpt::Default; break;
 142   case '3': OLvl = CodeGenOpt::Aggressive; break;
 143   }
 144
 145   // If we have a native target, initialize it to ensure it is linked in and
 146   // usable by the JIT.
 147   InitializeNativeTarget();
 148
 149   EE = ExecutionEngine::create(MP, ForceInterpreter, &ErrorMsg, OLvl);
 150   if (!EE) {
 151     if (!ErrorMsg.empty())
 152       errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
 153     else
 154       errs() << argv[0] << ": unknown error creating EE!\n";
 155     exit(1);
 156   }
 157
 158   EE->RegisterJITEventListener(createMacOSJITEventListener());
 159   EE->RegisterJITEventListener(createOProfileJITEventListener());
 160
 161   if (NoLazyCompilation)
 162     EE->DisableLazyCompilation();
 163
 164   // If the user specifically requested an argv[0] to pass into the program,
 165   // do it now.
 166   if (!FakeArgv0.empty()) {
 167     InputFile = FakeArgv0;
 168   } else {
 169     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 170     // might confuse the program.
 171     if (InputFile.rfind(".bc") == InputFile.length() - 3)
 172       InputFile.erase(InputFile.length() - 3);
 173   }
 174
 175   // Add the module's name to the start of the vector of arguments to main().
 176   InputArgv.insert(InputArgv.begin(), InputFile);
 177
 178   // Call the main function from M as if its signature were:
 179   //   int main (int argc, char **argv, const char **envp)
 180   // using the contents of Args to determine argc & argv, and the contents of
 181   // EnvVars to determine envp.
 182   //
 183   Function *EntryFn = Mod->getFunction(EntryFunc);
 184   if (!EntryFn) {
 185     errs() << '\'' << EntryFunc << "\' function not found in module.\n";
 186     return -1;
 187   }
 188
 189   // If the program doesn't explicitly call exit, we will need the Exit
 190   // function later on to make an explicit call, so get the function now.
 191   Constant *Exit = Mod->getOrInsertFunction("exit", Type::VoidTy,
 192                                                         Type::Int32Ty, NULL);
 193
 194   // Reset errno to zero on entry to main.
 195   errno = 0;
 196
 197   // Run static constructors.
 198   EE->runStaticConstructorsDestructors(false);
 199
 200   if (NoLazyCompilation) {
 201     for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
 202       Function *Fn = &*I;
 203       if (Fn != EntryFn && !Fn->isDeclaration())
 204         EE->getPointerToFunction(Fn);
 205     }
 206   }
 207
 208   // Run main.
 209   int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 210
 211   // Run static destructors.
 212   EE->runStaticConstructorsDestructors(true);
 213
 214   // If the program didn't call exit explicitly, we should call it now.
 215   // This ensures that any atexit handlers get called correctly.
 216   if (Function *ExitF = dyn_cast<Function>(Exit)) {
 217     std::vector<GenericValue> Args;
 218     GenericValue ResultGV;
 219     ResultGV.IntVal = APInt(32, Result);
 220     Args.push_back(ResultGV);
 221     EE->runFunction(ExitF, Args);
 222     errs() << "ERROR: exit(" << Result << ") returned!\n";
 223     abort();
 224   } else {
 225     errs() << "ERROR: exit defined with wrong prototype!\n";
 226     abort();
 227   }
 228 }