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/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 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 = getGlobalContext();
  98   atexit(do_shutdown);  // Call llvm_shutdown() on exit.
  99
 100   // If we have a native target, initialize it to ensure it is linked in and
 101   // usable by the JIT.
 102   InitializeNativeTarget();
 103
 104   cl::ParseCommandLineOptions(argc, argv,
 105                               "llvm interpreter & dynamic compiler\n");
 106
 107   // If the user doesn't want core files, disable them.
 108   if (DisableCoreFiles)
 109     sys::Process::PreventCoreFiles();
 110
 111   // Load the bitcode...
 112   std::string ErrorMsg;
 113   ModuleProvider *MP = NULL;
 114   if (MemoryBuffer *Buffer = MemoryBuffer::getFileOrSTDIN(InputFile,&ErrorMsg)){
 115     MP = getBitcodeModuleProvider(Buffer, Context, &ErrorMsg);
 116     if (!MP) delete Buffer;
 117   }
 118
 119   if (!MP) {
 120     errs() << argv[0] << ": error loading program '" << InputFile << "': "
 121            << ErrorMsg << "\n";
 122     exit(1);
 123   }
 124
 125   // Get the module as the MP could go away once EE takes over.
 126   Module *Mod = NoLazyCompilation
 127     ? MP->materializeModule(&ErrorMsg) : MP->getModule();
 128   if (!Mod) {
 129     errs() << argv[0] << ": bitcode didn't read correctly.\n";
 130     errs() << "Reason: " << ErrorMsg << "\n";
 131     exit(1);
 132   }
 133
 134   EngineBuilder builder(MP);
 135   builder.setErrorStr(&ErrorMsg);
 136   builder.setEngineKind(ForceInterpreter
 137                         ? EngineKind::Interpreter
 138                         : EngineKind::JIT);
 139
 140   // If we are supposed to override the target triple, do so now.
 141   if (!TargetTriple.empty())
 142     Mod->setTargetTriple(TargetTriple);
 143
 144   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 145   switch (OptLevel) {
 146   default:
 147     errs() << argv[0] << ": invalid optimization level.\n";
 148     return 1;
 149   case ' ': break;
 150   case '0': OLvl = CodeGenOpt::None; break;
 151   case '1':
 152   case '2': OLvl = CodeGenOpt::Default; break;
 153   case '3': OLvl = CodeGenOpt::Aggressive; break;
 154   }
 155   builder.setOptLevel(OLvl);
 156
 157   EE = builder.create();
 158   if (!EE) {
 159     if (!ErrorMsg.empty())
 160       errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
 161     else
 162       errs() << argv[0] << ": unknown error creating EE!\n";
 163     exit(1);
 164   }
 165
 166   EE->RegisterJITEventListener(createMacOSJITEventListener());
 167   EE->RegisterJITEventListener(createOProfileJITEventListener());
 168
 169   if (NoLazyCompilation)
 170     EE->DisableLazyCompilation();
 171
 172   // If the user specifically requested an argv[0] to pass into the program,
 173   // do it now.
 174   if (!FakeArgv0.empty()) {
 175     InputFile = FakeArgv0;
 176   } else {
 177     // Otherwise, if there is a .bc suffix on the executable strip it off, it
 178     // might confuse the program.
 179     if (InputFile.rfind(".bc") == InputFile.length() - 3)
 180       InputFile.erase(InputFile.length() - 3);
 181   }
 182
 183   // Add the module's name to the start of the vector of arguments to main().
 184   InputArgv.insert(InputArgv.begin(), InputFile);
 185
 186   // Call the main function from M as if its signature were:
 187   //   int main (int argc, char **argv, const char **envp)
 188   // using the contents of Args to determine argc & argv, and the contents of
 189   // EnvVars to determine envp.
 190   //
 191   Function *EntryFn = Mod->getFunction(EntryFunc);
 192   if (!EntryFn) {
 193     errs() << '\'' << EntryFunc << "\' function not found in module.\n";
 194     return -1;
 195   }
 196
 197   // If the program doesn't explicitly call exit, we will need the Exit
 198   // function later on to make an explicit call, so get the function now.
 199   Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
 200                                                     Type::getInt32Ty(Context),
 201                                                     NULL);
 202
 203   // Reset errno to zero on entry to main.
 204   errno = 0;
 205
 206   // Run static constructors.
 207   EE->runStaticConstructorsDestructors(false);
 208
 209   if (NoLazyCompilation) {
 210     for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
 211       Function *Fn = &*I;
 212       if (Fn != EntryFn && !Fn->isDeclaration())
 213         EE->getPointerToFunction(Fn);
 214     }
 215   }
 216
 217   // Run main.
 218   int Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 219
 220   // Run static destructors.
 221   EE->runStaticConstructorsDestructors(true);
 222
 223   // If the program didn't call exit explicitly, we should call it now.
 224   // This ensures that any atexit handlers get called correctly.
 225   if (Function *ExitF = dyn_cast<Function>(Exit)) {
 226     std::vector<GenericValue> Args;
 227     GenericValue ResultGV;
 228     ResultGV.IntVal = APInt(32, Result);
 229     Args.push_back(ResultGV);
 230     EE->runFunction(ExitF, Args);
 231     errs() << "ERROR: exit(" << Result << ") returned!\n";
 232     abort();
 233   } else {
 234     errs() << "ERROR: exit defined with wrong prototype!\n";
 235     abort();
 236   }
 237 }