lli.cpp revision eb59e4d5ac15604643540b3aa1e5628d2d440dfc 
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#define DEBUG_TYPE "lli"
17#include "llvm/IR/LLVMContext.h"
18#include "RemoteMemoryManager.h"
19#include "RemoteTarget.h"
20#include "llvm/ADT/Triple.h"
21#include "llvm/Bitcode/ReaderWriter.h"
22#include "llvm/CodeGen/LinkAllCodegenComponents.h"
23#include "llvm/ExecutionEngine/GenericValue.h"
24#include "llvm/ExecutionEngine/Interpreter.h"
25#include "llvm/ExecutionEngine/JIT.h"
26#include "llvm/ExecutionEngine/JITEventListener.h"
27#include "llvm/ExecutionEngine/JITMemoryManager.h"
28#include "llvm/ExecutionEngine/MCJIT.h"
29#include "llvm/ExecutionEngine/SectionMemoryManager.h"
30#include "llvm/IR/Module.h"
31#include "llvm/IR/Type.h"
32#include "llvm/IRReader/IRReader.h"
33#include "llvm/Support/CommandLine.h"
34#include "llvm/Support/Debug.h"
35#include "llvm/Support/DynamicLibrary.h"
36#include "llvm/Support/Format.h"
37#include "llvm/Support/ManagedStatic.h"
38#include "llvm/Support/MathExtras.h"
39#include "llvm/Support/Memory.h"
40#include "llvm/Support/MemoryBuffer.h"
41#include "llvm/Support/PluginLoader.h"
42#include "llvm/Support/PrettyStackTrace.h"
43#include "llvm/Support/Process.h"
44#include "llvm/Support/Program.h"
45#include "llvm/Support/Signals.h"
46#include "llvm/Support/SourceMgr.h"
47#include "llvm/Support/TargetSelect.h"
48#include "llvm/Support/raw_ostream.h"
49#include "llvm/Transforms/Instrumentation.h"
50#include <cerrno>
51
52#ifdef __CYGWIN__
53#include <cygwin/version.h>
54#if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
55#define DO_NOTHING_ATEXIT 1
56#endif
57#endif
58
59using namespace llvm;
60
61namespace {
62  cl::opt<std::string>
63  InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
64
65  cl::list<std::string>
66  InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
67
68  cl::opt<bool> ForceInterpreter("force-interpreter",
69                                 cl::desc("Force interpretation: disable JIT"),
70                                 cl::init(false));
71
72  cl::opt<bool> UseMCJIT(
73    "use-mcjit", cl::desc("Enable use of the MC-based JIT (if available)"),
74    cl::init(false));
75
76  cl::opt<bool> DebugIR(
77    "debug-ir", cl::desc("Generate debug information to allow debugging IR."),
78    cl::init(false));
79
80  // The MCJIT supports building for a target address space separate from
81  // the JIT compilation process. Use a forked process and a copying
82  // memory manager with IPC to execute using this functionality.
83  cl::opt<bool> RemoteMCJIT("remote-mcjit",
84    cl::desc("Execute MCJIT'ed code in a separate process."),
85    cl::init(false));
86
87  // Manually specify the child process for remote execution. This overrides
88  // the simulated remote execution that allocates address space for child
89  // execution. The child process resides in the disk and communicates with lli
90  // via stdin/stdout pipes.
91  cl::opt<std::string>
92  MCJITRemoteProcess("mcjit-remote-process",
93            cl::desc("Specify the filename of the process to launch "
94                     "for remote MCJIT execution.  If none is specified,"
95                     "\n\tremote execution will be simulated in-process."),
96            cl::value_desc("filename"),
97            cl::init(""));
98
99  // Determine optimization level.
100  cl::opt<char>
101  OptLevel("O",
102           cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
103                    "(default = '-O2')"),
104           cl::Prefix,
105           cl::ZeroOrMore,
106           cl::init(' '));
107
108  cl::opt<std::string>
109  TargetTriple("mtriple", cl::desc("Override target triple for module"));
110
111  cl::opt<std::string>
112  MArch("march",
113        cl::desc("Architecture to generate assembly for (see --version)"));
114
115  cl::opt<std::string>
116  MCPU("mcpu",
117       cl::desc("Target a specific cpu type (-mcpu=help for details)"),
118       cl::value_desc("cpu-name"),
119       cl::init(""));
120
121  cl::list<std::string>
122  MAttrs("mattr",
123         cl::CommaSeparated,
124         cl::desc("Target specific attributes (-mattr=help for details)"),
125         cl::value_desc("a1,+a2,-a3,..."));
126
127  cl::opt<std::string>
128  EntryFunc("entry-function",
129            cl::desc("Specify the entry function (default = 'main') "
130                     "of the executable"),
131            cl::value_desc("function"),
132            cl::init("main"));
133
134  cl::list<std::string>
135  ExtraModules("extra-modules",
136         cl::CommaSeparated,
137         cl::desc("Extra modules to be loaded"),
138         cl::value_desc("<input bitcode 2>,<input bitcode 3>,..."));
139
140  cl::opt<std::string>
141  FakeArgv0("fake-argv0",
142            cl::desc("Override the 'argv[0]' value passed into the executing"
143                     " program"), cl::value_desc("executable"));
144
145  cl::opt<bool>
146  DisableCoreFiles("disable-core-files", cl::Hidden,
147                   cl::desc("Disable emission of core files if possible"));
148
149  cl::opt<bool>
150  NoLazyCompilation("disable-lazy-compilation",
151                  cl::desc("Disable JIT lazy compilation"),
152                  cl::init(false));
153
154  cl::opt<Reloc::Model>
155  RelocModel("relocation-model",
156             cl::desc("Choose relocation model"),
157             cl::init(Reloc::Default),
158             cl::values(
159            clEnumValN(Reloc::Default, "default",
160                       "Target default relocation model"),
161            clEnumValN(Reloc::Static, "static",
162                       "Non-relocatable code"),
163            clEnumValN(Reloc::PIC_, "pic",
164                       "Fully relocatable, position independent code"),
165            clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
166                       "Relocatable external references, non-relocatable code"),
167            clEnumValEnd));
168
169  cl::opt<llvm::CodeModel::Model>
170  CMModel("code-model",
171          cl::desc("Choose code model"),
172          cl::init(CodeModel::JITDefault),
173          cl::values(clEnumValN(CodeModel::JITDefault, "default",
174                                "Target default JIT code model"),
175                     clEnumValN(CodeModel::Small, "small",
176                                "Small code model"),
177                     clEnumValN(CodeModel::Kernel, "kernel",
178                                "Kernel code model"),
179                     clEnumValN(CodeModel::Medium, "medium",
180                                "Medium code model"),
181                     clEnumValN(CodeModel::Large, "large",
182                                "Large code model"),
183                     clEnumValEnd));
184
185  cl::opt<bool>
186  GenerateSoftFloatCalls("soft-float",
187    cl::desc("Generate software floating point library calls"),
188    cl::init(false));
189
190  cl::opt<llvm::FloatABI::ABIType>
191  FloatABIForCalls("float-abi",
192                   cl::desc("Choose float ABI type"),
193                   cl::init(FloatABI::Default),
194                   cl::values(
195                     clEnumValN(FloatABI::Default, "default",
196                                "Target default float ABI type"),
197                     clEnumValN(FloatABI::Soft, "soft",
198                                "Soft float ABI (implied by -soft-float)"),
199                     clEnumValN(FloatABI::Hard, "hard",
200                                "Hard float ABI (uses FP registers)"),
201                     clEnumValEnd));
202  cl::opt<bool>
203// In debug builds, make this default to true.
204#ifdef NDEBUG
205#define EMIT_DEBUG false
206#else
207#define EMIT_DEBUG true
208#endif
209  EmitJitDebugInfo("jit-emit-debug",
210    cl::desc("Emit debug information to debugger"),
211    cl::init(EMIT_DEBUG));
212#undef EMIT_DEBUG
213
214  static cl::opt<bool>
215  EmitJitDebugInfoToDisk("jit-emit-debug-to-disk",
216    cl::Hidden,
217    cl::desc("Emit debug info objfiles to disk"),
218    cl::init(false));
219}
220
221static ExecutionEngine *EE = 0;
222
223static void do_shutdown() {
224  // Cygwin-1.5 invokes DLL's dtors before atexit handler.
225#ifndef DO_NOTHING_ATEXIT
226  delete EE;
227  llvm_shutdown();
228#endif
229}
230
231//===----------------------------------------------------------------------===//
232// main Driver function
233//
234int main(int argc, char **argv, char * const *envp) {
235  sys::PrintStackTraceOnErrorSignal();
236  PrettyStackTraceProgram X(argc, argv);
237
238  LLVMContext &Context = getGlobalContext();
239  atexit(do_shutdown);  // Call llvm_shutdown() on exit.
240
241  // If we have a native target, initialize it to ensure it is linked in and
242  // usable by the JIT.
243  InitializeNativeTarget();
244  InitializeNativeTargetAsmPrinter();
245  InitializeNativeTargetAsmParser();
246
247  cl::ParseCommandLineOptions(argc, argv,
248                              "llvm interpreter & dynamic compiler\n");
249
250  // If the user doesn't want core files, disable them.
251  if (DisableCoreFiles)
252    sys::Process::PreventCoreFiles();
253
254  // Load the bitcode...
255  SMDiagnostic Err;
256  Module *Mod = ParseIRFile(InputFile, Err, Context);
257  if (!Mod) {
258    Err.print(argv[0], errs());
259    return 1;
260  }
261
262  // If not jitting lazily, load the whole bitcode file eagerly too.
263  std::string ErrorMsg;
264  if (NoLazyCompilation) {
265    if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
266      errs() << argv[0] << ": bitcode didn't read correctly.\n";
267      errs() << "Reason: " << ErrorMsg << "\n";
268      exit(1);
269    }
270  }
271
272  if (DebugIR) {
273    if (!UseMCJIT) {
274      errs() << "warning: -debug-ir used without -use-mcjit. Only partial debug"
275        << " information will be emitted by the non-MC JIT engine. To see full"
276        << " source debug information, enable the flag '-use-mcjit'.\n";
277
278    }
279    ModulePass *DebugIRPass = createDebugIRPass();
280    DebugIRPass->runOnModule(*Mod);
281  }
282
283  EngineBuilder builder(Mod);
284  builder.setMArch(MArch);
285  builder.setMCPU(MCPU);
286  builder.setMAttrs(MAttrs);
287  builder.setRelocationModel(RelocModel);
288  builder.setCodeModel(CMModel);
289  builder.setErrorStr(&ErrorMsg);
290  builder.setEngineKind(ForceInterpreter
291                        ? EngineKind::Interpreter
292                        : EngineKind::JIT);
293
294  // If we are supposed to override the target triple, do so now.
295  if (!TargetTriple.empty())
296    Mod->setTargetTriple(Triple::normalize(TargetTriple));
297
298  // Enable MCJIT if desired.
299  RTDyldMemoryManager *RTDyldMM = 0;
300  if (UseMCJIT && !ForceInterpreter) {
301    builder.setUseMCJIT(true);
302    if (RemoteMCJIT)
303      RTDyldMM = new RemoteMemoryManager();
304    else
305      RTDyldMM = new SectionMemoryManager();
306    builder.setMCJITMemoryManager(RTDyldMM);
307  } else {
308    if (RemoteMCJIT) {
309      errs() << "error: Remote process execution requires -use-mcjit\n";
310      exit(1);
311    }
312    builder.setJITMemoryManager(ForceInterpreter ? 0 :
313                                JITMemoryManager::CreateDefaultMemManager());
314  }
315
316  CodeGenOpt::Level OLvl = CodeGenOpt::Default;
317  switch (OptLevel) {
318  default:
319    errs() << argv[0] << ": invalid optimization level.\n";
320    return 1;
321  case ' ': break;
322  case '0': OLvl = CodeGenOpt::None; break;
323  case '1': OLvl = CodeGenOpt::Less; break;
324  case '2': OLvl = CodeGenOpt::Default; break;
325  case '3': OLvl = CodeGenOpt::Aggressive; break;
326  }
327  builder.setOptLevel(OLvl);
328
329  TargetOptions Options;
330  Options.UseSoftFloat = GenerateSoftFloatCalls;
331  if (FloatABIForCalls != FloatABI::Default)
332    Options.FloatABIType = FloatABIForCalls;
333  if (GenerateSoftFloatCalls)
334    FloatABIForCalls = FloatABI::Soft;
335
336  // Remote target execution doesn't handle EH or debug registration.
337  if (!RemoteMCJIT) {
338    Options.JITEmitDebugInfo = EmitJitDebugInfo;
339    Options.JITEmitDebugInfoToDisk = EmitJitDebugInfoToDisk;
340  }
341
342  builder.setTargetOptions(Options);
343
344  EE = builder.create();
345  if (!EE) {
346    if (!ErrorMsg.empty())
347      errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
348    else
349      errs() << argv[0] << ": unknown error creating EE!\n";
350    exit(1);
351  }
352
353  // Load any additional modules specified on the command line.
354  for (unsigned i = 0, e = ExtraModules.size(); i != e; ++i) {
355    Module *XMod = ParseIRFile(ExtraModules[i], Err, Context);
356    if (!XMod) {
357      Err.print(argv[0], errs());
358      return 1;
359    }
360    EE->addModule(XMod);
361  }
362
363  // The following functions have no effect if their respective profiling
364  // support wasn't enabled in the build configuration.
365  EE->RegisterJITEventListener(
366                JITEventListener::createOProfileJITEventListener());
367  EE->RegisterJITEventListener(
368                JITEventListener::createIntelJITEventListener());
369
370  if (!NoLazyCompilation && RemoteMCJIT) {
371    errs() << "warning: remote mcjit does not support lazy compilation\n";
372    NoLazyCompilation = true;
373  }
374  EE->DisableLazyCompilation(NoLazyCompilation);
375
376  // If the user specifically requested an argv[0] to pass into the program,
377  // do it now.
378  if (!FakeArgv0.empty()) {
379    InputFile = FakeArgv0;
380  } else {
381    // Otherwise, if there is a .bc suffix on the executable strip it off, it
382    // might confuse the program.
383    if (StringRef(InputFile).endswith(".bc"))
384      InputFile.erase(InputFile.length() - 3);
385  }
386
387  // Add the module's name to the start of the vector of arguments to main().
388  InputArgv.insert(InputArgv.begin(), InputFile);
389
390  // Call the main function from M as if its signature were:
391  //   int main (int argc, char **argv, const char **envp)
392  // using the contents of Args to determine argc & argv, and the contents of
393  // EnvVars to determine envp.
394  //
395  Function *EntryFn = Mod->getFunction(EntryFunc);
396  if (!EntryFn) {
397    errs() << '\'' << EntryFunc << "\' function not found in module.\n";
398    return -1;
399  }
400
401  // If the program doesn't explicitly call exit, we will need the Exit
402  // function later on to make an explicit call, so get the function now.
403  Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
404                                                    Type::getInt32Ty(Context),
405                                                    NULL);
406
407  // Reset errno to zero on entry to main.
408  errno = 0;
409
410  int Result;
411
412  if (!RemoteMCJIT) {
413    // Run static constructors.
414    if (UseMCJIT && !ForceInterpreter) {
415      // Give MCJIT a chance to apply relocations and set page permissions.
416      EE->finalizeObject();
417    }
418    EE->runStaticConstructorsDestructors(false);
419
420    if (!UseMCJIT && NoLazyCompilation) {
421      for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
422        Function *Fn = &*I;
423        if (Fn != EntryFn && !Fn->isDeclaration())
424          EE->getPointerToFunction(Fn);
425      }
426    }
427
428    // Trigger compilation separately so code regions that need to be
429    // invalidated will be known.
430    (void)EE->getPointerToFunction(EntryFn);
431    // Clear instruction cache before code will be executed.
432    if (RTDyldMM)
433      static_cast<SectionMemoryManager*>(RTDyldMM)->invalidateInstructionCache();
434
435    // Run main.
436    Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
437
438    // Run static destructors.
439    EE->runStaticConstructorsDestructors(true);
440
441    // If the program didn't call exit explicitly, we should call it now.
442    // This ensures that any atexit handlers get called correctly.
443    if (Function *ExitF = dyn_cast<Function>(Exit)) {
444      std::vector<GenericValue> Args;
445      GenericValue ResultGV;
446      ResultGV.IntVal = APInt(32, Result);
447      Args.push_back(ResultGV);
448      EE->runFunction(ExitF, Args);
449      errs() << "ERROR: exit(" << Result << ") returned!\n";
450      abort();
451    } else {
452      errs() << "ERROR: exit defined with wrong prototype!\n";
453      abort();
454    }
455  } else {
456    // else == "if (RemoteMCJIT)"
457
458    // Remote target MCJIT doesn't (yet) support static constructors. No reason
459    // it couldn't. This is a limitation of the LLI implemantation, not the
460    // MCJIT itself. FIXME.
461    //
462    RemoteMemoryManager *MM = static_cast<RemoteMemoryManager*>(RTDyldMM);
463    // Everything is prepared now, so lay out our program for the target
464    // address space, assign the section addresses to resolve any relocations,
465    // and send it to the target.
466
467    OwningPtr<RemoteTarget> Target;
468    if (!MCJITRemoteProcess.empty()) { // Remote execution on a child process
469      if (!RemoteTarget::hostSupportsExternalRemoteTarget()) {
470        errs() << "Warning: host does not support external remote targets.\n"
471               << "  Defaulting to simulated remote execution\n";
472        Target.reset(RemoteTarget::createRemoteTarget());
473      } else {
474        std::string ChildEXE = sys::FindProgramByName(MCJITRemoteProcess);
475        if (ChildEXE == "") {
476          errs() << "Unable to find child target: '\''" << MCJITRemoteProcess << "\'\n";
477          return -1;
478        }
479        Target.reset(RemoteTarget::createExternalRemoteTarget(ChildEXE));
480      }
481    } else {
482      // No child process name provided, use simulated remote execution.
483      Target.reset(RemoteTarget::createRemoteTarget());
484    }
485
486    // Give the memory manager a pointer to our remote target interface object.
487    MM->setRemoteTarget(Target.get());
488
489    // Create the remote target.
490    Target->create();
491
492    // Since we're executing in a (at least simulated) remote address space,
493    // we can't use the ExecutionEngine::runFunctionAsMain(). We have to
494    // grab the function address directly here and tell the remote target
495    // to execute the function.
496    //
497    // Our memory manager will map generated code into the remote address
498    // space as it is loaded and copy the bits over during the finalizeMemory
499    // operation.
500    //
501    // FIXME: argv and envp handling.
502    uint64_t Entry = EE->getFunctionAddress(EntryFn->getName().str());
503
504    DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
505                 << format("%llx", Entry) << "\n");
506
507    if (Target->executeCode(Entry, Result))
508      errs() << "ERROR: " << Target->getErrorMsg() << "\n";
509
510    // Like static constructors, the remote target MCJIT support doesn't handle
511    // this yet. It could. FIXME.
512
513    // Stop the remote target
514    Target->stop();
515  }
516
517  return Result;
518}
519