lli.cpp revision 77b4c69165090dcbf60e20492e41479489f64a6c 
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 "RecordingMemoryManager.h"
18#include "RemoteTarget.h"
19#include "llvm/LLVMContext.h"
20#include "llvm/Module.h"
21#include "llvm/Type.h"
22#include "llvm/ADT/Triple.h"
23#include "llvm/Bitcode/ReaderWriter.h"
24#include "llvm/CodeGen/LinkAllCodegenComponents.h"
25#include "llvm/ExecutionEngine/GenericValue.h"
26#include "llvm/ExecutionEngine/Interpreter.h"
27#include "llvm/ExecutionEngine/JIT.h"
28#include "llvm/ExecutionEngine/JITEventListener.h"
29#include "llvm/ExecutionEngine/JITMemoryManager.h"
30#include "llvm/ExecutionEngine/MCJIT.h"
31#include "llvm/Support/CommandLine.h"
32#include "llvm/Support/IRReader.h"
33#include "llvm/Support/ManagedStatic.h"
34#include "llvm/Support/MemoryBuffer.h"
35#include "llvm/Support/PluginLoader.h"
36#include "llvm/Support/PrettyStackTrace.h"
37#include "llvm/Support/raw_ostream.h"
38#include "llvm/Support/Format.h"
39#include "llvm/Support/Process.h"
40#include "llvm/Support/Signals.h"
41#include "llvm/Support/TargetSelect.h"
42#include "llvm/Support/Debug.h"
43#include "llvm/Support/DynamicLibrary.h"
44#include "llvm/Support/Memory.h"
45#include <cerrno>
46
47#ifdef __linux__
48// These includes used by LLIMCJITMemoryManager::getPointerToNamedFunction()
49// for Glibc trickery. Look comments in this function for more information.
50#ifdef HAVE_SYS_STAT_H
51#include <sys/stat.h>
52#endif
53#include <fcntl.h>
54#include <unistd.h>
55#endif
56
57#ifdef __CYGWIN__
58#include <cygwin/version.h>
59#if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
60#define DO_NOTHING_ATEXIT 1
61#endif
62#endif
63
64using namespace llvm;
65
66namespace {
67  cl::opt<std::string>
68  InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
69
70  cl::list<std::string>
71  InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
72
73  cl::opt<bool> ForceInterpreter("force-interpreter",
74                                 cl::desc("Force interpretation: disable JIT"),
75                                 cl::init(false));
76
77  cl::opt<bool> UseMCJIT(
78    "use-mcjit", cl::desc("Enable use of the MC-based JIT (if available)"),
79    cl::init(false));
80
81  // The MCJIT supports building for a target address space separate from
82  // the JIT compilation process. Use a forked process and a copying
83  // memory manager with IPC to execute using this functionality.
84  cl::opt<bool> RemoteMCJIT("remote-mcjit",
85    cl::desc("Execute MCJIT'ed code in a separate process."),
86    cl::init(false));
87
88  // Determine optimization level.
89  cl::opt<char>
90  OptLevel("O",
91           cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
92                    "(default = '-O2')"),
93           cl::Prefix,
94           cl::ZeroOrMore,
95           cl::init(' '));
96
97  cl::opt<std::string>
98  TargetTriple("mtriple", cl::desc("Override target triple for module"));
99
100  cl::opt<std::string>
101  MArch("march",
102        cl::desc("Architecture to generate assembly for (see --version)"));
103
104  cl::opt<std::string>
105  MCPU("mcpu",
106       cl::desc("Target a specific cpu type (-mcpu=help for details)"),
107       cl::value_desc("cpu-name"),
108       cl::init(""));
109
110  cl::list<std::string>
111  MAttrs("mattr",
112         cl::CommaSeparated,
113         cl::desc("Target specific attributes (-mattr=help for details)"),
114         cl::value_desc("a1,+a2,-a3,..."));
115
116  cl::opt<std::string>
117  EntryFunc("entry-function",
118            cl::desc("Specify the entry function (default = 'main') "
119                     "of the executable"),
120            cl::value_desc("function"),
121            cl::init("main"));
122
123  cl::opt<std::string>
124  FakeArgv0("fake-argv0",
125            cl::desc("Override the 'argv[0]' value passed into the executing"
126                     " program"), cl::value_desc("executable"));
127
128  cl::opt<bool>
129  DisableCoreFiles("disable-core-files", cl::Hidden,
130                   cl::desc("Disable emission of core files if possible"));
131
132  cl::opt<bool>
133  NoLazyCompilation("disable-lazy-compilation",
134                  cl::desc("Disable JIT lazy compilation"),
135                  cl::init(false));
136
137  cl::opt<Reloc::Model>
138  RelocModel("relocation-model",
139             cl::desc("Choose relocation model"),
140             cl::init(Reloc::Default),
141             cl::values(
142            clEnumValN(Reloc::Default, "default",
143                       "Target default relocation model"),
144            clEnumValN(Reloc::Static, "static",
145                       "Non-relocatable code"),
146            clEnumValN(Reloc::PIC_, "pic",
147                       "Fully relocatable, position independent code"),
148            clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
149                       "Relocatable external references, non-relocatable code"),
150            clEnumValEnd));
151
152  cl::opt<llvm::CodeModel::Model>
153  CMModel("code-model",
154          cl::desc("Choose code model"),
155          cl::init(CodeModel::JITDefault),
156          cl::values(clEnumValN(CodeModel::JITDefault, "default",
157                                "Target default JIT code model"),
158                     clEnumValN(CodeModel::Small, "small",
159                                "Small code model"),
160                     clEnumValN(CodeModel::Kernel, "kernel",
161                                "Kernel code model"),
162                     clEnumValN(CodeModel::Medium, "medium",
163                                "Medium code model"),
164                     clEnumValN(CodeModel::Large, "large",
165                                "Large code model"),
166                     clEnumValEnd));
167
168  cl::opt<bool>
169  EnableJITExceptionHandling("jit-enable-eh",
170    cl::desc("Emit exception handling information"),
171    cl::init(false));
172
173  cl::opt<bool>
174  GenerateSoftFloatCalls("soft-float",
175    cl::desc("Generate software floating point library calls"),
176    cl::init(false));
177
178  cl::opt<llvm::FloatABI::ABIType>
179  FloatABIForCalls("float-abi",
180                   cl::desc("Choose float ABI type"),
181                   cl::init(FloatABI::Default),
182                   cl::values(
183                     clEnumValN(FloatABI::Default, "default",
184                                "Target default float ABI type"),
185                     clEnumValN(FloatABI::Soft, "soft",
186                                "Soft float ABI (implied by -soft-float)"),
187                     clEnumValN(FloatABI::Hard, "hard",
188                                "Hard float ABI (uses FP registers)"),
189                     clEnumValEnd));
190  cl::opt<bool>
191// In debug builds, make this default to true.
192#ifdef NDEBUG
193#define EMIT_DEBUG false
194#else
195#define EMIT_DEBUG true
196#endif
197  EmitJitDebugInfo("jit-emit-debug",
198    cl::desc("Emit debug information to debugger"),
199    cl::init(EMIT_DEBUG));
200#undef EMIT_DEBUG
201
202  static cl::opt<bool>
203  EmitJitDebugInfoToDisk("jit-emit-debug-to-disk",
204    cl::Hidden,
205    cl::desc("Emit debug info objfiles to disk"),
206    cl::init(false));
207}
208
209static ExecutionEngine *EE = 0;
210
211static void do_shutdown() {
212  // Cygwin-1.5 invokes DLL's dtors before atexit handler.
213#ifndef DO_NOTHING_ATEXIT
214  delete EE;
215  llvm_shutdown();
216#endif
217}
218
219// Memory manager for MCJIT
220class LLIMCJITMemoryManager : public JITMemoryManager {
221public:
222  SmallVector<sys::MemoryBlock, 16> AllocatedDataMem;
223  SmallVector<sys::MemoryBlock, 16> AllocatedCodeMem;
224  SmallVector<sys::MemoryBlock, 16> FreeCodeMem;
225
226  LLIMCJITMemoryManager() { }
227  ~LLIMCJITMemoryManager();
228
229  virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
230                                       unsigned SectionID);
231
232  virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
233                                       unsigned SectionID);
234
235  virtual void *getPointerToNamedFunction(const std::string &Name,
236                                          bool AbortOnFailure = true);
237
238  // Invalidate instruction cache for code sections. Some platforms with
239  // separate data cache and instruction cache require explicit cache flush,
240  // otherwise JIT code manipulations (like resolved relocations) will get to
241  // the data cache but not to the instruction cache.
242  virtual void invalidateInstructionCache();
243
244  // The MCJITMemoryManager doesn't use the following functions, so we don't
245  // need implement them.
246  virtual void setMemoryWritable() {
247    llvm_unreachable("Unexpected call!");
248  }
249  virtual void setMemoryExecutable() {
250    llvm_unreachable("Unexpected call!");
251  }
252  virtual void setPoisonMemory(bool poison) {
253    llvm_unreachable("Unexpected call!");
254  }
255  virtual void AllocateGOT() {
256    llvm_unreachable("Unexpected call!");
257  }
258  virtual uint8_t *getGOTBase() const {
259    llvm_unreachable("Unexpected call!");
260    return 0;
261  }
262  virtual uint8_t *startFunctionBody(const Function *F,
263                                     uintptr_t &ActualSize){
264    llvm_unreachable("Unexpected call!");
265    return 0;
266  }
267  virtual uint8_t *allocateStub(const GlobalValue* F, unsigned StubSize,
268                                unsigned Alignment) {
269    llvm_unreachable("Unexpected call!");
270    return 0;
271  }
272  virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
273                               uint8_t *FunctionEnd) {
274    llvm_unreachable("Unexpected call!");
275  }
276  virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
277    llvm_unreachable("Unexpected call!");
278    return 0;
279  }
280  virtual uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) {
281    llvm_unreachable("Unexpected call!");
282    return 0;
283  }
284  virtual void deallocateFunctionBody(void *Body) {
285    llvm_unreachable("Unexpected call!");
286  }
287  virtual uint8_t* startExceptionTable(const Function* F,
288                                       uintptr_t &ActualSize) {
289    llvm_unreachable("Unexpected call!");
290    return 0;
291  }
292  virtual void endExceptionTable(const Function *F, uint8_t *TableStart,
293                                 uint8_t *TableEnd, uint8_t* FrameRegister) {
294    llvm_unreachable("Unexpected call!");
295  }
296  virtual void deallocateExceptionTable(void *ET) {
297    llvm_unreachable("Unexpected call!");
298  }
299};
300
301uint8_t *LLIMCJITMemoryManager::allocateDataSection(uintptr_t Size,
302                                                    unsigned Alignment,
303                                                    unsigned SectionID) {
304  if (!Alignment)
305    Alignment = 16;
306  uint8_t *Addr = (uint8_t*)calloc((Size + Alignment - 1)/Alignment, Alignment);
307  AllocatedDataMem.push_back(sys::MemoryBlock(Addr, Size));
308  return Addr;
309}
310
311uint8_t *LLIMCJITMemoryManager::allocateCodeSection(uintptr_t Size,
312                                                    unsigned Alignment,
313                                                    unsigned SectionID) {
314  if (!Alignment)
315    Alignment = 16;
316  unsigned NeedAllocate = Alignment * ((Size + Alignment - 1)/Alignment + 1);
317  uintptr_t Addr = 0;
318  // Look in the list of free code memory regions and use a block there if one
319  // is available.
320  for (int i = 0, e = FreeCodeMem.size(); i != e; ++i) {
321    sys::MemoryBlock &MB = FreeCodeMem[i];
322    if (MB.size() >= NeedAllocate) {
323      Addr = (uintptr_t)MB.base();
324      uintptr_t EndOfBlock = Addr + MB.size();
325      // Align the address.
326      Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
327      // Store cutted free memory block.
328      FreeCodeMem[i] = sys::MemoryBlock((void*)(Addr + Size),
329                                        EndOfBlock - Addr - Size);
330      return (uint8_t*)Addr;
331    }
332  }
333
334  // No pre-allocated free block was large enough. Allocate a new memory region.
335  sys::MemoryBlock MB = sys::Memory::AllocateRWX(NeedAllocate, 0, 0);
336
337  AllocatedCodeMem.push_back(MB);
338  Addr = (uintptr_t)MB.base();
339  uintptr_t EndOfBlock = Addr + MB.size();
340  // Align the address.
341  Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
342  // The AllocateRWX may allocate much more memory than we need. In this case,
343  // we store the unused memory as a free memory block.
344  unsigned FreeSize = EndOfBlock-Addr-Size;
345  if (FreeSize > 16)
346    FreeCodeMem.push_back(sys::MemoryBlock((void*)(Addr + Size), FreeSize));
347
348  // Return aligned address
349  return (uint8_t*)Addr;
350}
351
352void LLIMCJITMemoryManager::invalidateInstructionCache() {
353  for (int i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
354    sys::Memory::InvalidateInstructionCache(AllocatedCodeMem[i].base(),
355                                            AllocatedCodeMem[i].size());
356}
357
358static int jit_noop() {
359  return 0;
360}
361
362void *LLIMCJITMemoryManager::getPointerToNamedFunction(const std::string &Name,
363                                                       bool AbortOnFailure) {
364#if defined(__linux__)
365  //===--------------------------------------------------------------------===//
366  // Function stubs that are invoked instead of certain library calls
367  //
368  // Force the following functions to be linked in to anything that uses the
369  // JIT. This is a hack designed to work around the all-too-clever Glibc
370  // strategy of making these functions work differently when inlined vs. when
371  // not inlined, and hiding their real definitions in a separate archive file
372  // that the dynamic linker can't see. For more info, search for
373  // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
374  if (Name == "stat") return (void*)(intptr_t)&stat;
375  if (Name == "fstat") return (void*)(intptr_t)&fstat;
376  if (Name == "lstat") return (void*)(intptr_t)&lstat;
377  if (Name == "stat64") return (void*)(intptr_t)&stat64;
378  if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
379  if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
380  if (Name == "atexit") return (void*)(intptr_t)&atexit;
381  if (Name == "mknod") return (void*)(intptr_t)&mknod;
382#endif // __linux__
383
384  // We should not invoke parent's ctors/dtors from generated main()!
385  // On Mingw and Cygwin, the symbol __main is resolved to
386  // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
387  // (and register wrong callee's dtors with atexit(3)).
388  // We expect ExecutionEngine::runStaticConstructorsDestructors()
389  // is called before ExecutionEngine::runFunctionAsMain() is called.
390  if (Name == "__main") return (void*)(intptr_t)&jit_noop;
391
392  const char *NameStr = Name.c_str();
393  void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
394  if (Ptr) return Ptr;
395
396  // If it wasn't found and if it starts with an underscore ('_') character,
397  // try again without the underscore.
398  if (NameStr[0] == '_') {
399    Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
400    if (Ptr) return Ptr;
401  }
402
403  if (AbortOnFailure)
404    report_fatal_error("Program used external function '" + Name +
405                      "' which could not be resolved!");
406  return 0;
407}
408
409LLIMCJITMemoryManager::~LLIMCJITMemoryManager() {
410  for (unsigned i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
411    sys::Memory::ReleaseRWX(AllocatedCodeMem[i]);
412  for (unsigned i = 0, e = AllocatedDataMem.size(); i != e; ++i)
413    free(AllocatedDataMem[i].base());
414}
415
416
417void layoutRemoteTargetMemory(RemoteTarget *T, RecordingMemoryManager *JMM) {
418  // Lay out our sections in order, with all the code sections first, then
419  // all the data sections.
420  uint64_t CurOffset = 0;
421  unsigned MaxAlign = T->getPageAlignment();
422  SmallVector<std::pair<const void*, uint64_t>, 16> Offsets;
423  SmallVector<unsigned, 16> Sizes;
424  for (RecordingMemoryManager::const_code_iterator I = JMM->code_begin(),
425                                                   E = JMM->code_end();
426       I != E; ++I) {
427    DEBUG(dbgs() << "code region: size " << I->first.size()
428                 << ", alignment " << I->second << "\n");
429    // Align the current offset up to whatever is needed for the next
430    // section.
431    unsigned Align = I->second;
432    CurOffset = (CurOffset + Align - 1) / Align * Align;
433    // Save off the address of the new section and allocate its space.
434    Offsets.push_back(std::pair<const void*,uint64_t>(I->first.base(), CurOffset));
435    Sizes.push_back(I->first.size());
436    CurOffset += I->first.size();
437  }
438  // Adjust to keep code and data aligned on seperate pages.
439  CurOffset = (CurOffset + MaxAlign - 1) / MaxAlign * MaxAlign;
440  unsigned FirstDataIndex = Offsets.size();
441  for (RecordingMemoryManager::const_data_iterator I = JMM->data_begin(),
442                                                   E = JMM->data_end();
443       I != E; ++I) {
444    DEBUG(dbgs() << "data region: size " << I->first.size()
445                 << ", alignment " << I->second << "\n");
446    // Align the current offset up to whatever is needed for the next
447    // section.
448    unsigned Align = I->second;
449    CurOffset = (CurOffset + Align - 1) / Align * Align;
450    // Save off the address of the new section and allocate its space.
451    Offsets.push_back(std::pair<const void*,uint64_t>(I->first.base(), CurOffset));
452    Sizes.push_back(I->first.size());
453    CurOffset += I->first.size();
454  }
455
456  // Allocate space in the remote target.
457  uint64_t RemoteAddr;
458  if (T->allocateSpace(CurOffset, MaxAlign, RemoteAddr))
459    report_fatal_error(T->getErrorMsg());
460  // Map the section addresses so relocations will get updated in the local
461  // copies of the sections.
462  for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
463    uint64_t Addr = RemoteAddr + Offsets[i].second;
464    EE->mapSectionAddress(const_cast<void*>(Offsets[i].first), Addr);
465
466    DEBUG(dbgs() << "  Mapping local: " << Offsets[i].first
467                 << " to remote: " << format("%#018x", Addr) << "\n");
468
469  }
470  // Now load it all to the target.
471  for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
472    uint64_t Addr = RemoteAddr + Offsets[i].second;
473
474    if (i < FirstDataIndex) {
475      T->loadCode(Addr, Offsets[i].first, Sizes[i]);
476
477      DEBUG(dbgs() << "  loading code: " << Offsets[i].first
478            << " to remote: " << format("%#018x", Addr) << "\n");
479    } else {
480      T->loadData(Addr, Offsets[i].first, Sizes[i]);
481
482      DEBUG(dbgs() << "  loading data: " << Offsets[i].first
483            << " to remote: " << format("%#018x", Addr) << "\n");
484    }
485
486  }
487}
488
489//===----------------------------------------------------------------------===//
490// main Driver function
491//
492int main(int argc, char **argv, char * const *envp) {
493  sys::PrintStackTraceOnErrorSignal();
494  PrettyStackTraceProgram X(argc, argv);
495
496  LLVMContext &Context = getGlobalContext();
497  atexit(do_shutdown);  // Call llvm_shutdown() on exit.
498
499  // If we have a native target, initialize it to ensure it is linked in and
500  // usable by the JIT.
501  InitializeNativeTarget();
502  InitializeNativeTargetAsmPrinter();
503
504  cl::ParseCommandLineOptions(argc, argv,
505                              "llvm interpreter & dynamic compiler\n");
506
507  // If the user doesn't want core files, disable them.
508  if (DisableCoreFiles)
509    sys::Process::PreventCoreFiles();
510
511  // Load the bitcode...
512  SMDiagnostic Err;
513  Module *Mod = ParseIRFile(InputFile, Err, Context);
514  if (!Mod) {
515    Err.print(argv[0], errs());
516    return 1;
517  }
518
519  // If not jitting lazily, load the whole bitcode file eagerly too.
520  std::string ErrorMsg;
521  if (NoLazyCompilation) {
522    if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
523      errs() << argv[0] << ": bitcode didn't read correctly.\n";
524      errs() << "Reason: " << ErrorMsg << "\n";
525      exit(1);
526    }
527  }
528
529  EngineBuilder builder(Mod);
530  builder.setMArch(MArch);
531  builder.setMCPU(MCPU);
532  builder.setMAttrs(MAttrs);
533  builder.setRelocationModel(RelocModel);
534  builder.setCodeModel(CMModel);
535  builder.setErrorStr(&ErrorMsg);
536  builder.setEngineKind(ForceInterpreter
537                        ? EngineKind::Interpreter
538                        : EngineKind::JIT);
539
540  // If we are supposed to override the target triple, do so now.
541  if (!TargetTriple.empty())
542    Mod->setTargetTriple(Triple::normalize(TargetTriple));
543
544  // Enable MCJIT if desired.
545  JITMemoryManager *JMM = 0;
546  if (UseMCJIT && !ForceInterpreter) {
547    builder.setUseMCJIT(true);
548    if (RemoteMCJIT)
549      JMM = new RecordingMemoryManager();
550    else
551      JMM = new LLIMCJITMemoryManager();
552    builder.setJITMemoryManager(JMM);
553  } else {
554    if (RemoteMCJIT) {
555      errs() << "error: Remote process execution requires -use-mcjit\n";
556      exit(1);
557    }
558    builder.setJITMemoryManager(ForceInterpreter ? 0 :
559                                JITMemoryManager::CreateDefaultMemManager());
560  }
561
562  CodeGenOpt::Level OLvl = CodeGenOpt::Default;
563  switch (OptLevel) {
564  default:
565    errs() << argv[0] << ": invalid optimization level.\n";
566    return 1;
567  case ' ': break;
568  case '0': OLvl = CodeGenOpt::None; break;
569  case '1': OLvl = CodeGenOpt::Less; break;
570  case '2': OLvl = CodeGenOpt::Default; break;
571  case '3': OLvl = CodeGenOpt::Aggressive; break;
572  }
573  builder.setOptLevel(OLvl);
574
575  TargetOptions Options;
576  Options.UseSoftFloat = GenerateSoftFloatCalls;
577  if (FloatABIForCalls != FloatABI::Default)
578    Options.FloatABIType = FloatABIForCalls;
579  if (GenerateSoftFloatCalls)
580    FloatABIForCalls = FloatABI::Soft;
581
582  // Remote target execution doesn't handle EH or debug registration.
583  if (!RemoteMCJIT) {
584    Options.JITExceptionHandling = EnableJITExceptionHandling;
585    Options.JITEmitDebugInfo = EmitJitDebugInfo;
586    Options.JITEmitDebugInfoToDisk = EmitJitDebugInfoToDisk;
587  }
588
589  builder.setTargetOptions(Options);
590
591  EE = builder.create();
592  if (!EE) {
593    if (!ErrorMsg.empty())
594      errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
595    else
596      errs() << argv[0] << ": unknown error creating EE!\n";
597    exit(1);
598  }
599
600  // The following functions have no effect if their respective profiling
601  // support wasn't enabled in the build configuration.
602  EE->RegisterJITEventListener(
603                JITEventListener::createOProfileJITEventListener());
604  EE->RegisterJITEventListener(
605                JITEventListener::createIntelJITEventListener());
606
607  if (!NoLazyCompilation && RemoteMCJIT) {
608    errs() << "warning: remote mcjit does not support lazy compilation\n";
609    NoLazyCompilation = true;
610  }
611  EE->DisableLazyCompilation(NoLazyCompilation);
612
613  // If the user specifically requested an argv[0] to pass into the program,
614  // do it now.
615  if (!FakeArgv0.empty()) {
616    InputFile = FakeArgv0;
617  } else {
618    // Otherwise, if there is a .bc suffix on the executable strip it off, it
619    // might confuse the program.
620    if (StringRef(InputFile).endswith(".bc"))
621      InputFile.erase(InputFile.length() - 3);
622  }
623
624  // Add the module's name to the start of the vector of arguments to main().
625  InputArgv.insert(InputArgv.begin(), InputFile);
626
627  // Call the main function from M as if its signature were:
628  //   int main (int argc, char **argv, const char **envp)
629  // using the contents of Args to determine argc & argv, and the contents of
630  // EnvVars to determine envp.
631  //
632  Function *EntryFn = Mod->getFunction(EntryFunc);
633  if (!EntryFn) {
634    errs() << '\'' << EntryFunc << "\' function not found in module.\n";
635    return -1;
636  }
637
638  // If the program doesn't explicitly call exit, we will need the Exit
639  // function later on to make an explicit call, so get the function now.
640  Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
641                                                    Type::getInt32Ty(Context),
642                                                    NULL);
643
644  // Reset errno to zero on entry to main.
645  errno = 0;
646
647  // Remote target MCJIT doesn't (yet) support static constructors. No reason
648  // it couldn't. This is a limitation of the LLI implemantation, not the
649  // MCJIT itself. FIXME.
650  //
651  // Run static constructors.
652  if (!RemoteMCJIT)
653    EE->runStaticConstructorsDestructors(false);
654
655  if (NoLazyCompilation) {
656    for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
657      Function *Fn = &*I;
658      if (Fn != EntryFn && !Fn->isDeclaration())
659        EE->getPointerToFunction(Fn);
660    }
661  }
662
663  int Result;
664  if (RemoteMCJIT) {
665    RecordingMemoryManager *MM = static_cast<RecordingMemoryManager*>(JMM);
666    // Everything is prepared now, so lay out our program for the target
667    // address space, assign the section addresses to resolve any relocations,
668    // and send it to the target.
669    RemoteTarget Target;
670    Target.create();
671
672    // Ask for a pointer to the entry function. This triggers the actual
673    // compilation.
674    (void)EE->getPointerToFunction(EntryFn);
675
676    // Enough has been compiled to execute the entry function now, so
677    // layout the target memory.
678    layoutRemoteTargetMemory(&Target, MM);
679
680    // Since we're executing in a (at least simulated) remote address space,
681    // we can't use the ExecutionEngine::runFunctionAsMain(). We have to
682    // grab the function address directly here and tell the remote target
683    // to execute the function.
684    // FIXME: argv and envp handling.
685    uint64_t Entry = (uint64_t)EE->getPointerToFunction(EntryFn);
686
687    DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at "
688                 << format("%#18x", Entry) << "\n");
689
690    if (Target.executeCode(Entry, Result))
691      errs() << "ERROR: " << Target.getErrorMsg() << "\n";
692
693    Target.stop();
694  } else {
695    // Trigger compilation separately so code regions that need to be
696    // invalidated will be known.
697    (void)EE->getPointerToFunction(EntryFn);
698    // Clear instruction cache before code will be executed.
699    if (JMM)
700      static_cast<LLIMCJITMemoryManager*>(JMM)->invalidateInstructionCache();
701
702    // Run main.
703    Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
704  }
705
706  // Like static constructors, the remote target MCJIT support doesn't handle
707  // this yet. It could. FIXME.
708  if (!RemoteMCJIT) {
709    // Run static destructors.
710    EE->runStaticConstructorsDestructors(true);
711
712    // If the program didn't call exit explicitly, we should call it now.
713    // This ensures that any atexit handlers get called correctly.
714    if (Function *ExitF = dyn_cast<Function>(Exit)) {
715      std::vector<GenericValue> Args;
716      GenericValue ResultGV;
717      ResultGV.IntVal = APInt(32, Result);
718      Args.push_back(ResultGV);
719      EE->runFunction(ExitF, Args);
720      errs() << "ERROR: exit(" << Result << ") returned!\n";
721      abort();
722    } else {
723      errs() << "ERROR: exit defined with wrong prototype!\n";
724      abort();
725    }
726  }
727  return Result;
728}
729