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 <cerrno>
  35 using namespace llvm;
  36
  37 namespace {
  38   cl::opt<std::string>
  39   InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
  40
  41   cl::list<std::string>
  42   InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
  43
  44   cl::opt<bool> ForceInterpreter("force-interpreter",
  45                                  cl::desc("Force interpretation: disable JIT"),
  46                                  cl::init(false));
  47
  48   // Determine optimization level.
  49   cl::opt<char>
  50   OptLevel("O",
  51            cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
  52                     "(default = '-O2')"),
  53            cl::Prefix,
  54            cl::ZeroOrMore,
  55            cl::init(' '));
  56
  57   cl::opt<std::string>
  58   TargetTriple("mtriple", cl::desc("Override target triple for module"));
  59
  60   cl::opt<std::string>
  61   EntryFunc("entry-function",
  62             cl::desc("Specify the entry function (default = 'main') "
  63                      "of the executable"),
  64             cl::value_desc("function"),
  65             cl::init("main"));
  66
  67   cl::opt<std::string>
  68   FakeArgv0("fake-argv0",
  69             cl::desc("Override the 'argv[0]' value passed into the executing"
  70                      " program"), cl::value_desc("executable"));
  71
  72   cl::opt<bool>
  73   DisableCoreFiles("disable-core-files", cl::Hidden,
  74                    cl::desc("Disable emission of core files if possible"));
  75
  76   cl::opt<bool>
  77   NoLazyCompilation("disable-lazy-compilation",
  78                   cl::desc("Disable JIT lazy compilation"),
  79                   cl::init(false));
  80 }
  81
  82 static ExecutionEngine *EE = 0;
  83
  84 static void do_shutdown() {
  85   delete EE;
  86   llvm_shutdown();
  87 }
  88
  89 //===----------------------------------------------------------------------===//
  90 // main Driver function
  91 //
  92 int main(int argc, char **argv, char * const *envp) {
  93   sys::PrintStackTraceOnErrorSignal();
  94   PrettyStackTraceProgram X(argc, argv);
  95
  96   LLVMContext &Context = getGlobalContext();
  97   atexit(do_shutdown);  // Call llvm_shutdown() on exit.
  98
  99   // If we have a native target, initialize it to ensure it is linked in and
 100   // usable by the JIT.
 101   InitializeNativeTarget();
 102
 103   cl::ParseCommandLineOptions(argc, argv,
 104                               "llvm interpreter & dynamic compiler\n");
 105
 106   // If the user doesn't want core files, disable them.
 107   if (DisableCoreFiles)
 108     sys::Process::PreventCoreFiles();
 109
 110   // Load the bitcode...
 111   std::string ErrorMsg;
 112   ModuleProvider *MP = NULL;
 113   if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFile,&ErrorMsg)){
 114     MP = getBitcodeModuleProvider(Buffer, Context, &ErrorMsg);
 115     if (!MP) delete Buffer;
 116   }
 117
 118   if (!MP) {
 119     errs() << argv[0] << ": error loading program '" << InputFile << "': "
 120            << ErrorMsg << "\n";
 121     exit(1);
 122   }
 123
 124   // Get the module as the MP could go away once EE takes over.
 125   Module *Mod = NoLazyCompilation
 126     ? MP->materializeModule(&ErrorMsg) : MP->getModule();
 127   if (!Mod) {
 128     errs() << argv[0] << ": bitcode didn't read correctly.\n";
 129     errs() << "Reason: " << ErrorMsg << "\n";
 130     exit(1);
 131   }
 132
 133   EngineBuilder builder(MP);
 134   builder.setErrorStr(&ErrorMsg);
 135   builder.setEngineKind(ForceInterpreter
 136                         ? EngineKind::Interpreter
 137                         : EngineKind::JIT);
 138
 139   // If we are supposed to override the target triple, do so now.
 140   if (!TargetTriple.empty())
 141     Mod->setTargetTriple(TargetTriple);
 142
 143   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 144   switch (OptLevel) {
 145   default:
 146     errs() << argv[0] << ": invalid optimization level.\n";
 147     return 1;
 148   case ' ': break;
 149   case '0': OLvl = CodeGenOpt::None; break;
 150   case '1':
 151   case '2': OLvl = CodeGenOpt::Default; break;
 152   case '3': OLvl = CodeGenOpt::Aggressive; break;
 153   }
 154   builder.setOptLevel(OLvl);
 155
 156   EE = builder.create();
 157   if (!EE) {
 158     if (!ErrorMsg.empty())
 159       errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
 160     else
 161       errs() << argv[0] << ": unknown error creating EE!\n";
 162     exit(1);
 163   }
 164
 165   EE->RegisterJITEventListener(createMacOSJITEventListener());
 166   EE->RegisterJITEventListener(createOProfileJITEventListener());
 167
 168   if (NoLazyCompilation)
 169     EE->DisableLazyCompilation();
 170
 171   // If the user specifically requested an argv[0] to pass into the program,
 172   // do it now.
 173   if (!FakeArgv0.empty()) {
 174     InputFile = FakeArgv0;
 175   } else {
 176     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 177     // might confuse the program.
 178     if (InputFile.rfind(".bc") == InputFile.length() - 3)
 179       InputFile.erase(InputFile.length() - 3);
 180   }
 181
 182   // Add the module's name to the start of the vector of arguments to main().
 183   InputArgv.insert(InputArgv.begin(), InputFile);
 184
 185   // Call the main function from M as if its signature were:
 186   //   int main (int argc, char **argv, const char **envp)
 187   // using the contents of Args to determine argc & argv, and the contents of
 188   // EnvVars to determine envp.
 189   //
 190   Function *EntryFn = Mod->getFunction(EntryFunc);
 191   if (!EntryFn) {
 192     errs() << '\'' << EntryFunc << "\' function not found in module.\n";
 193     return -1;
 194   }
 195
 196   // If the program doesn't explicitly call exit, we will need the Exit
 197   // function later on to make an explicit call, so get the function now.
 198   Constant *Exit = Mod->getOrInsertFunction("exit", Type::VoidTy,
 199                                                         Type::Int32Ty, NULL);
 200
 201   // Reset errno to zero on entry to main.
 202   errno = 0;
 203
 204   // Run static constructors.
 205   EE->runStaticConstructorsDestructors(false);
 206
 207   if (NoLazyCompilation) {
 208     for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
 209       Function *Fn = &*I;
 210       if (Fn != EntryFn && !Fn->isDeclaration())
 211         EE->getPointerToFunction(Fn);
 212     }
 213   }
 214
 215   // Run main.
 216   int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 217
 218   // Run static destructors.
 219   EE->runStaticConstructorsDestructors(true);
 220
 221   // If the program didn't call exit explicitly, we should call it now.
 222   // This ensures that any atexit handlers get called correctly.
 223   if (Function *ExitF = dyn_cast<Function>(Exit)) {
 224     std::vector<GenericValue> Args;
 225     GenericValue ResultGV;
 226     ResultGV.IntVal = APInt(32, Result);
 227     Args.push_back(ResultGV);
 228     EE->runFunction(ExitF, Args);
 229     errs() << "ERROR: exit(" << Result << ") returned!\n";
 230     abort();
 231   } else {
 232     errs() << "ERROR: exit defined with wrong prototype!\n";
 233     abort();
 234   }
 235 }