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// In debug builds, make this default to true.
175#ifdef NDEBUG
176#define EMIT_DEBUG false
177#else
178#define EMIT_DEBUG true
179#endif
180  EmitJitDebugInfo("jit-emit-debug",
181    cl::desc("Emit debug information to debugger"),
182    cl::init(EMIT_DEBUG));
183#undef EMIT_DEBUG
184
185  static cl::opt<bool>
186  EmitJitDebugInfoToDisk("jit-emit-debug-to-disk",
187    cl::Hidden,
188    cl::desc("Emit debug info objfiles to disk"),
189    cl::init(false));
190}
191
192static ExecutionEngine *EE = 0;
193
194static void do_shutdown() {
195  // Cygwin-1.5 invokes DLL's dtors before atexit handler.
196#ifndef DO_NOTHING_ATEXIT
197  delete EE;
198  llvm_shutdown();
199#endif
200}
201
202// Memory manager for MCJIT
203class LLIMCJITMemoryManager : public JITMemoryManager {
204public:
205  SmallVector<sys::MemoryBlock, 16> AllocatedDataMem;
206  SmallVector<sys::MemoryBlock, 16> AllocatedCodeMem;
207  SmallVector<sys::MemoryBlock, 16> FreeCodeMem;
208
209  LLIMCJITMemoryManager() { }
210  ~LLIMCJITMemoryManager();
211
212  virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
213                                       unsigned SectionID);
214
215  virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
216                                       unsigned SectionID);
217
218  virtual void *getPointerToNamedFunction(const std::string &Name,
219                                          bool AbortOnFailure = true);
220
221  // Invalidate instruction cache for code sections. Some platforms with
222  // separate data cache and instruction cache require explicit cache flush,
223  // otherwise JIT code manipulations (like resolved relocations) will get to
224  // the data cache but not to the instruction cache.
225  virtual void invalidateInstructionCache();
226
227  // The MCJITMemoryManager doesn't use the following functions, so we don't
228  // need implement them.
229  virtual void setMemoryWritable() {
230    llvm_unreachable("Unexpected call!");
231  }
232  virtual void setMemoryExecutable() {
233    llvm_unreachable("Unexpected call!");
234  }
235  virtual void setPoisonMemory(bool poison) {
236    llvm_unreachable("Unexpected call!");
237  }
238  virtual void AllocateGOT() {
239    llvm_unreachable("Unexpected call!");
240  }
241  virtual uint8_t *getGOTBase() const {
242    llvm_unreachable("Unexpected call!");
243    return 0;
244  }
245  virtual uint8_t *startFunctionBody(const Function *F,
246                                     uintptr_t &ActualSize){
247    llvm_unreachable("Unexpected call!");
248    return 0;
249  }
250  virtual uint8_t *allocateStub(const GlobalValue* F, unsigned StubSize,
251                                unsigned Alignment) {
252    llvm_unreachable("Unexpected call!");
253    return 0;
254  }
255  virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
256                               uint8_t *FunctionEnd) {
257    llvm_unreachable("Unexpected call!");
258  }
259  virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
260    llvm_unreachable("Unexpected call!");
261    return 0;
262  }
263  virtual uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) {
264    llvm_unreachable("Unexpected call!");
265    return 0;
266  }
267  virtual void deallocateFunctionBody(void *Body) {
268    llvm_unreachable("Unexpected call!");
269  }
270  virtual uint8_t* startExceptionTable(const Function* F,
271                                       uintptr_t &ActualSize) {
272    llvm_unreachable("Unexpected call!");
273    return 0;
274  }
275  virtual void endExceptionTable(const Function *F, uint8_t *TableStart,
276                                 uint8_t *TableEnd, uint8_t* FrameRegister) {
277    llvm_unreachable("Unexpected call!");
278  }
279  virtual void deallocateExceptionTable(void *ET) {
280    llvm_unreachable("Unexpected call!");
281  }
282};
283
284uint8_t *LLIMCJITMemoryManager::allocateDataSection(uintptr_t Size,
285                                                    unsigned Alignment,
286                                                    unsigned SectionID) {
287  if (!Alignment)
288    Alignment = 16;
289  uint8_t *Addr = (uint8_t*)calloc((Size + Alignment - 1)/Alignment, Alignment);
290  AllocatedDataMem.push_back(sys::MemoryBlock(Addr, Size));
291  return Addr;
292}
293
294uint8_t *LLIMCJITMemoryManager::allocateCodeSection(uintptr_t Size,
295                                                    unsigned Alignment,
296                                                    unsigned SectionID) {
297  if (!Alignment)
298    Alignment = 16;
299  unsigned NeedAllocate = Alignment * ((Size + Alignment - 1)/Alignment + 1);
300  uintptr_t Addr = 0;
301  // Look in the list of free code memory regions and use a block there if one
302  // is available.
303  for (int i = 0, e = FreeCodeMem.size(); i != e; ++i) {
304    sys::MemoryBlock &MB = FreeCodeMem[i];
305    if (MB.size() >= NeedAllocate) {
306      Addr = (uintptr_t)MB.base();
307      uintptr_t EndOfBlock = Addr + MB.size();
308      // Align the address.
309      Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
310      // Store cutted free memory block.
311      FreeCodeMem[i] = sys::MemoryBlock((void*)(Addr + Size),
312                                        EndOfBlock - Addr - Size);
313      return (uint8_t*)Addr;
314    }
315  }
316
317  // No pre-allocated free block was large enough. Allocate a new memory region.
318  sys::MemoryBlock MB = sys::Memory::AllocateRWX(NeedAllocate, 0, 0);
319
320  AllocatedCodeMem.push_back(MB);
321  Addr = (uintptr_t)MB.base();
322  uintptr_t EndOfBlock = Addr + MB.size();
323  // Align the address.
324  Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
325  // The AllocateRWX may allocate much more memory than we need. In this case,
326  // we store the unused memory as a free memory block.
327  unsigned FreeSize = EndOfBlock-Addr-Size;
328  if (FreeSize > 16)
329    FreeCodeMem.push_back(sys::MemoryBlock((void*)(Addr + Size), FreeSize));
330
331  // Return aligned address
332  return (uint8_t*)Addr;
333}
334
335void LLIMCJITMemoryManager::invalidateInstructionCache() {
336  for (int i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
337    sys::Memory::InvalidateInstructionCache(AllocatedCodeMem[i].base(),
338                                            AllocatedCodeMem[i].size());
339}
340
341void *LLIMCJITMemoryManager::getPointerToNamedFunction(const std::string &Name,
342                                                       bool AbortOnFailure) {
343#if defined(__linux__)
344  //===--------------------------------------------------------------------===//
345  // Function stubs that are invoked instead of certain library calls
346  //
347  // Force the following functions to be linked in to anything that uses the
348  // JIT. This is a hack designed to work around the all-too-clever Glibc
349  // strategy of making these functions work differently when inlined vs. when
350  // not inlined, and hiding their real definitions in a separate archive file
351  // that the dynamic linker can't see. For more info, search for
352  // 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
353  if (Name == "stat") return (void*)(intptr_t)&stat;
354  if (Name == "fstat") return (void*)(intptr_t)&fstat;
355  if (Name == "lstat") return (void*)(intptr_t)&lstat;
356  if (Name == "stat64") return (void*)(intptr_t)&stat64;
357  if (Name == "fstat64") return (void*)(intptr_t)&fstat64;
358  if (Name == "lstat64") return (void*)(intptr_t)&lstat64;
359  if (Name == "atexit") return (void*)(intptr_t)&atexit;
360  if (Name == "mknod") return (void*)(intptr_t)&mknod;
361#endif // __linux__
362
363  const char *NameStr = Name.c_str();
364  void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
365  if (Ptr) return Ptr;
366
367  // If it wasn't found and if it starts with an underscore ('_') character,
368  // try again without the underscore.
369  if (NameStr[0] == '_') {
370    Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
371    if (Ptr) return Ptr;
372  }
373
374  if (AbortOnFailure)
375    report_fatal_error("Program used external function '" + Name +
376                      "' which could not be resolved!");
377  return 0;
378}
379
380LLIMCJITMemoryManager::~LLIMCJITMemoryManager() {
381  for (unsigned i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
382    sys::Memory::ReleaseRWX(AllocatedCodeMem[i]);
383  for (unsigned i = 0, e = AllocatedDataMem.size(); i != e; ++i)
384    free(AllocatedDataMem[i].base());
385}
386
387
388void layoutRemoteTargetMemory(RemoteTarget *T, RecordingMemoryManager *JMM) {
389  // Lay out our sections in order, with all the code sections first, then
390  // all the data sections.
391  uint64_t CurOffset = 0;
392  unsigned MaxAlign = T->getPageAlignment();
393  SmallVector<std::pair<const void*, uint64_t>, 16> Offsets;
394  SmallVector<unsigned, 16> Sizes;
395  for (RecordingMemoryManager::const_code_iterator I = JMM->code_begin(),
396                                                   E = JMM->code_end();
397       I != E; ++I) {
398    DEBUG(dbgs() << "code region: size " << I->first.size()
399                 << ", alignment " << I->second << "\n");
400    // Align the current offset up to whatever is needed for the next
401    // section.
402    unsigned Align = I->second;
403    CurOffset = (CurOffset + Align - 1) / Align * Align;
404    // Save off the address of the new section and allocate its space.
405    Offsets.push_back(std::pair<const void*,uint64_t>(I->first.base(), CurOffset));
406    Sizes.push_back(I->first.size());
407    CurOffset += I->first.size();
408  }
409  // Adjust to keep code and data aligned on seperate pages.
410  CurOffset = (CurOffset + MaxAlign - 1) / MaxAlign * MaxAlign;
411  unsigned FirstDataIndex = Offsets.size();
412  for (RecordingMemoryManager::const_data_iterator I = JMM->data_begin(),
413                                                   E = JMM->data_end();
414       I != E; ++I) {
415    DEBUG(dbgs() << "data region: size " << I->first.size()
416                 << ", alignment " << I->second << "\n");
417    // Align the current offset up to whatever is needed for the next
418    // section.
419    unsigned Align = I->second;
420    CurOffset = (CurOffset + Align - 1) / Align * Align;
421    // Save off the address of the new section and allocate its space.
422    Offsets.push_back(std::pair<const void*,uint64_t>(I->first.base(), CurOffset));
423    Sizes.push_back(I->first.size());
424    CurOffset += I->first.size();
425  }
426
427  // Allocate space in the remote target.
428  uint64_t RemoteAddr;
429  if (T->allocateSpace(CurOffset, MaxAlign, RemoteAddr))
430    report_fatal_error(T->getErrorMsg());
431  // Map the section addresses so relocations will get updated in the local
432  // copies of the sections.
433  for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
434    uint64_t Addr = RemoteAddr + Offsets[i].second;
435    EE->mapSectionAddress(const_cast<void*>(Offsets[i].first), Addr);
436
437    DEBUG(dbgs() << "  Mapping local: " << Offsets[i].first
438                 << " to remote: " << format("%#018x", Addr) << "\n");
439
440  }
441  // Now load it all to the target.
442  for (unsigned i = 0, e = Offsets.size(); i != e; ++i) {
443    uint64_t Addr = RemoteAddr + Offsets[i].second;
444
445    if (i < FirstDataIndex) {
446      T->loadCode(Addr, Offsets[i].first, Sizes[i]);
447
448      DEBUG(dbgs() << "  loading code: " << Offsets[i].first
449            << " to remote: " << format("%#018x", Addr) << "\n");
450    } else {
451      T->loadData(Addr, Offsets[i].first, Sizes[i]);
452
453      DEBUG(dbgs() << "  loading data: " << Offsets[i].first
454            << " to remote: " << format("%#018x", Addr) << "\n");
455    }
456
457  }
458}
459
460//===----------------------------------------------------------------------===//
461// main Driver function
462//
463int main(int argc, char **argv, char * const *envp) {
464  sys::PrintStackTraceOnErrorSignal();
465  PrettyStackTraceProgram X(argc, argv);
466
467  LLVMContext &Context = getGlobalContext();
468  atexit(do_shutdown);  // Call llvm_shutdown() on exit.
469
470  // If we have a native target, initialize it to ensure it is linked in and
471  // usable by the JIT.
472  InitializeNativeTarget();
473  InitializeNativeTargetAsmPrinter();
474
475  cl::ParseCommandLineOptions(argc, argv,
476                              "llvm interpreter & dynamic compiler\n");
477
478  // If the user doesn't want core files, disable them.
479  if (DisableCoreFiles)
480    sys::Process::PreventCoreFiles();
481
482  // Load the bitcode...
483  SMDiagnostic Err;
484  Module *Mod = ParseIRFile(InputFile, Err, Context);
485  if (!Mod) {
486    Err.print(argv[0], errs());
487    return 1;
488  }
489
490  // If not jitting lazily, load the whole bitcode file eagerly too.
491  std::string ErrorMsg;
492  if (NoLazyCompilation) {
493    if (Mod->MaterializeAllPermanently(&ErrorMsg)) {
494      errs() << argv[0] << ": bitcode didn't read correctly.\n";
495      errs() << "Reason: " << ErrorMsg << "\n";
496      exit(1);
497    }
498  }
499
500  EngineBuilder builder(Mod);
501  builder.setMArch(MArch);
502  builder.setMCPU(MCPU);
503  builder.setMAttrs(MAttrs);
504  builder.setRelocationModel(RelocModel);
505  builder.setCodeModel(CMModel);
506  builder.setErrorStr(&ErrorMsg);
507  builder.setEngineKind(ForceInterpreter
508                        ? EngineKind::Interpreter
509                        : EngineKind::JIT);
510
511  // If we are supposed to override the target triple, do so now.
512  if (!TargetTriple.empty())
513    Mod->setTargetTriple(Triple::normalize(TargetTriple));
514
515  // Enable MCJIT if desired.
516  JITMemoryManager *JMM = 0;
517  if (UseMCJIT && !ForceInterpreter) {
518    builder.setUseMCJIT(true);
519    if (RemoteMCJIT)
520      JMM = new RecordingMemoryManager();
521    else
522      JMM = new LLIMCJITMemoryManager();
523    builder.setJITMemoryManager(JMM);
524  } else {
525    if (RemoteMCJIT) {
526      errs() << "error: Remote process execution requires -use-mcjit\n";
527      exit(1);
528    }
529    builder.setJITMemoryManager(ForceInterpreter ? 0 :
530                                JITMemoryManager::CreateDefaultMemManager());
531  }
532
533  CodeGenOpt::Level OLvl = CodeGenOpt::Default;
534  switch (OptLevel) {
535  default:
536    errs() << argv[0] << ": invalid optimization level.\n";
537    return 1;
538  case ' ': break;
539  case '0': OLvl = CodeGenOpt::None; break;
540  case '1': OLvl = CodeGenOpt::Less; break;
541  case '2': OLvl = CodeGenOpt::Default; break;
542  case '3': OLvl = CodeGenOpt::Aggressive; break;
543  }
544  builder.setOptLevel(OLvl);
545
546  // Remote target execution doesn't handle EH or debug registration.
547  if (!RemoteMCJIT) {
548    TargetOptions Options;
549    Options.JITExceptionHandling = EnableJITExceptionHandling;
550    Options.JITEmitDebugInfo = EmitJitDebugInfo;
551    Options.JITEmitDebugInfoToDisk = EmitJitDebugInfoToDisk;
552    builder.setTargetOptions(Options);
553  }
554
555  EE = builder.create();
556  if (!EE) {
557    if (!ErrorMsg.empty())
558      errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
559    else
560      errs() << argv[0] << ": unknown error creating EE!\n";
561    exit(1);
562  }
563
564  // The following functions have no effect if their respective profiling
565  // support wasn't enabled in the build configuration.
566  EE->RegisterJITEventListener(
567                JITEventListener::createOProfileJITEventListener());
568  EE->RegisterJITEventListener(
569                JITEventListener::createIntelJITEventListener());
570
571  if (!NoLazyCompilation && RemoteMCJIT) {
572    errs() << "warning: remote mcjit does not support lazy compilation\n";
573    NoLazyCompilation = true;
574  }
575  EE->DisableLazyCompilation(NoLazyCompilation);
576
577  // If the user specifically requested an argv[0] to pass into the program,
578  // do it now.
579  if (!FakeArgv0.empty()) {
580    InputFile = FakeArgv0;
581  } else {
582    // Otherwise, if there is a .bc suffix on the executable strip it off, it
583    // might confuse the program.
584    if (StringRef(InputFile).endswith(".bc"))
585      InputFile.erase(InputFile.length() - 3);
586  }
587
588  // Add the module's name to the start of the vector of arguments to main().
589  InputArgv.insert(InputArgv.begin(), InputFile);
590
591  // Call the main function from M as if its signature were:
592  //   int main (int argc, char **argv, const char **envp)
593  // using the contents of Args to determine argc & argv, and the contents of
594  // EnvVars to determine envp.
595  //
596  Function *EntryFn = Mod->getFunction(EntryFunc);
597  if (!EntryFn) {
598    errs() << '\'' << EntryFunc << "\' function not found in module.\n";
599    return -1;
600  }
601
602  // If the program doesn't explicitly call exit, we will need the Exit
603  // function later on to make an explicit call, so get the function now.
604  Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
605                                                    Type::getInt32Ty(Context),
606                                                    NULL);
607
608  // Reset errno to zero on entry to main.
609  errno = 0;
610
611  // Remote target MCJIT doesn't (yet) support static constructors. No reason
612  // it couldn't. This is a limitation of the LLI implemantation, not the
613  // MCJIT itself. FIXME.
614  //
615  // Run static constructors.
616  if (!RemoteMCJIT)
617    EE->runStaticConstructorsDestructors(false);
618
619  if (NoLazyCompilation) {
620    for (Module::iterator I = Mod->begin(), E = Mod->end(); I != E; ++I) {
621      Function *Fn = &*I;
622      if (Fn != EntryFn && !Fn->isDeclaration())
623        EE->getPointerToFunction(Fn);
624    }
625  }
626
627  int Result;
628  if (RemoteMCJIT) {
629    RecordingMemoryManager *MM = static_cast<RecordingMemoryManager*>(JMM);
630    // Everything is prepared now, so lay out our program for the target
631    // address space, assign the section addresses to resolve any relocations,
632    // and send it to the target.
633    RemoteTarget Target;
634    Target.create();
635
636    // Ask for a pointer to the entry function. This triggers the actual
637    // compilation.
638    (void)EE->getPointerToFunction(EntryFn);
639
640    // Enough has been compiled to execute the entry function now, so
641    // layout the target memory.
642    layoutRemoteTargetMemory(&Target, MM);
643
644    // Since we're executing in a (at least simulated) remote address space,
645    // we can't use the ExecutionEngine::runFunctionAsMain(). We have to
646    // grab the function address directly here and tell the remote target
647    // to execute the function.
648    // FIXME: argv and envp handling.
649    uint64_t Entry = (uint64_t)EE->getPointerToFunction(EntryFn);
650
651    DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at "
652                 << format("%#18x", Entry) << "\n");
653
654    if (Target.executeCode(Entry, Result))
655      errs() << "ERROR: " << Target.getErrorMsg() << "\n";
656
657    Target.stop();
658  } else {
659    // Trigger compilation separately so code regions that need to be
660    // invalidated will be known.
661    (void)EE->getPointerToFunction(EntryFn);
662    // Clear instruction cache before code will be executed.
663    if (JMM)
664      static_cast<LLIMCJITMemoryManager*>(JMM)->invalidateInstructionCache();
665
666    // Run main.
667    Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
668  }
669
670  // Like static constructors, the remote target MCJIT support doesn't handle
671  // this yet. It could. FIXME.
672  if (!RemoteMCJIT) {
673    // Run static destructors.
674    EE->runStaticConstructorsDestructors(true);
675
676    // If the program didn't call exit explicitly, we should call it now.
677    // This ensures that any atexit handlers get called correctly.
678    if (Function *ExitF = dyn_cast<Function>(Exit)) {
679      std::vector<GenericValue> Args;
680      GenericValue ResultGV;
681      ResultGV.IntVal = APInt(32, Result);
682      Args.push_back(ResultGV);
683      EE->runFunction(ExitF, Args);
684      errs() << "ERROR: exit(" << Result << ") returned!\n";
685      abort();
686    } else {
687      errs() << "ERROR: exit defined with wrong prototype!\n";
688      abort();
689    }
690  }
691  return Result;
692}
693