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/IR/LLVMContext.h"
17#include "RemoteMemoryManager.h"
18#include "RemoteTarget.h"
19#include "RemoteTargetExternal.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/ObjectCache.h"
30#include "llvm/ExecutionEngine/SectionMemoryManager.h"
31#include "llvm/IR/IRBuilder.h"
32#include "llvm/IR/Module.h"
33#include "llvm/IR/Type.h"
34#include "llvm/IR/TypeBuilder.h"
35#include "llvm/IRReader/IRReader.h"
36#include "llvm/Object/Archive.h"
37#include "llvm/Object/ObjectFile.h"
38#include "llvm/Support/CommandLine.h"
39#include "llvm/Support/Debug.h"
40#include "llvm/Support/DynamicLibrary.h"
41#include "llvm/Support/Format.h"
42#include "llvm/Support/ManagedStatic.h"
43#include "llvm/Support/MathExtras.h"
44#include "llvm/Support/Memory.h"
45#include "llvm/Support/MemoryBuffer.h"
46#include "llvm/Support/PluginLoader.h"
47#include "llvm/Support/PrettyStackTrace.h"
48#include "llvm/Support/Process.h"
49#include "llvm/Support/Program.h"
50#include "llvm/Support/Signals.h"
51#include "llvm/Support/SourceMgr.h"
52#include "llvm/Support/TargetSelect.h"
53#include "llvm/Support/raw_ostream.h"
54#include "llvm/Transforms/Instrumentation.h"
55#include <cerrno>
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
66#define DEBUG_TYPE "lli"
67
68namespace {
69  cl::opt<std::string>
70  InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
71
72  cl::list<std::string>
73  InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
74
75  cl::opt<bool> ForceInterpreter("force-interpreter",
76                                 cl::desc("Force interpretation: disable JIT"),
77                                 cl::init(false));
78
79  cl::opt<bool> UseMCJIT(
80    "use-mcjit", cl::desc("Enable use of the MC-based JIT (if available)"),
81    cl::init(false));
82
83  cl::opt<bool> DebugIR(
84    "debug-ir", cl::desc("Generate debug information to allow debugging IR."),
85    cl::init(false));
86
87  // The MCJIT supports building for a target address space separate from
88  // the JIT compilation process. Use a forked process and a copying
89  // memory manager with IPC to execute using this functionality.
90  cl::opt<bool> RemoteMCJIT("remote-mcjit",
91    cl::desc("Execute MCJIT'ed code in a separate process."),
92    cl::init(false));
93
94  // Manually specify the child process for remote execution. This overrides
95  // the simulated remote execution that allocates address space for child
96  // execution. The child process will be executed and will communicate with
97  // lli via stdin/stdout pipes.
98  cl::opt<std::string>
99  ChildExecPath("mcjit-remote-process",
100                cl::desc("Specify the filename of the process to launch "
101                         "for remote MCJIT execution.  If none is specified,"
102                         "\n\tremote execution will be simulated in-process."),
103                cl::value_desc("filename"), cl::init(""));
104
105  // Determine optimization level.
106  cl::opt<char>
107  OptLevel("O",
108           cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
109                    "(default = '-O2')"),
110           cl::Prefix,
111           cl::ZeroOrMore,
112           cl::init(' '));
113
114  cl::opt<std::string>
115  TargetTriple("mtriple", cl::desc("Override target triple for module"));
116
117  cl::opt<std::string>
118  MArch("march",
119        cl::desc("Architecture to generate assembly for (see --version)"));
120
121  cl::opt<std::string>
122  MCPU("mcpu",
123       cl::desc("Target a specific cpu type (-mcpu=help for details)"),
124       cl::value_desc("cpu-name"),
125       cl::init(""));
126
127  cl::list<std::string>
128  MAttrs("mattr",
129         cl::CommaSeparated,
130         cl::desc("Target specific attributes (-mattr=help for details)"),
131         cl::value_desc("a1,+a2,-a3,..."));
132
133  cl::opt<std::string>
134  EntryFunc("entry-function",
135            cl::desc("Specify the entry function (default = 'main') "
136                     "of the executable"),
137            cl::value_desc("function"),
138            cl::init("main"));
139
140  cl::list<std::string>
141  ExtraModules("extra-module",
142         cl::desc("Extra modules to be loaded"),
143         cl::value_desc("input bitcode"));
144
145  cl::list<std::string>
146  ExtraObjects("extra-object",
147         cl::desc("Extra object files to be loaded"),
148         cl::value_desc("input object"));
149
150  cl::list<std::string>
151  ExtraArchives("extra-archive",
152         cl::desc("Extra archive files to be loaded"),
153         cl::value_desc("input archive"));
154
155  cl::opt<bool>
156  EnableCacheManager("enable-cache-manager",
157        cl::desc("Use cache manager to save/load mdoules"),
158        cl::init(false));
159
160  cl::opt<std::string>
161  ObjectCacheDir("object-cache-dir",
162                  cl::desc("Directory to store cached object files "
163                           "(must be user writable)"),
164                  cl::init(""));
165
166  cl::opt<std::string>
167  FakeArgv0("fake-argv0",
168            cl::desc("Override the 'argv[0]' value passed into the executing"
169                     " program"), cl::value_desc("executable"));
170
171  cl::opt<bool>
172  DisableCoreFiles("disable-core-files", cl::Hidden,
173                   cl::desc("Disable emission of core files if possible"));
174
175  cl::opt<bool>
176  NoLazyCompilation("disable-lazy-compilation",
177                  cl::desc("Disable JIT lazy compilation"),
178                  cl::init(false));
179
180  cl::opt<Reloc::Model>
181  RelocModel("relocation-model",
182             cl::desc("Choose relocation model"),
183             cl::init(Reloc::Default),
184             cl::values(
185            clEnumValN(Reloc::Default, "default",
186                       "Target default relocation model"),
187            clEnumValN(Reloc::Static, "static",
188                       "Non-relocatable code"),
189            clEnumValN(Reloc::PIC_, "pic",
190                       "Fully relocatable, position independent code"),
191            clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
192                       "Relocatable external references, non-relocatable code"),
193            clEnumValEnd));
194
195  cl::opt<llvm::CodeModel::Model>
196  CMModel("code-model",
197          cl::desc("Choose code model"),
198          cl::init(CodeModel::JITDefault),
199          cl::values(clEnumValN(CodeModel::JITDefault, "default",
200                                "Target default JIT code model"),
201                     clEnumValN(CodeModel::Small, "small",
202                                "Small code model"),
203                     clEnumValN(CodeModel::Kernel, "kernel",
204                                "Kernel code model"),
205                     clEnumValN(CodeModel::Medium, "medium",
206                                "Medium code model"),
207                     clEnumValN(CodeModel::Large, "large",
208                                "Large code model"),
209                     clEnumValEnd));
210
211  cl::opt<bool>
212  GenerateSoftFloatCalls("soft-float",
213    cl::desc("Generate software floating point library calls"),
214    cl::init(false));
215
216  cl::opt<llvm::FloatABI::ABIType>
217  FloatABIForCalls("float-abi",
218                   cl::desc("Choose float ABI type"),
219                   cl::init(FloatABI::Default),
220                   cl::values(
221                     clEnumValN(FloatABI::Default, "default",
222                                "Target default float ABI type"),
223                     clEnumValN(FloatABI::Soft, "soft",
224                                "Soft float ABI (implied by -soft-float)"),
225                     clEnumValN(FloatABI::Hard, "hard",
226                                "Hard float ABI (uses FP registers)"),
227                     clEnumValEnd));
228  cl::opt<bool>
229// In debug builds, make this default to true.
230#ifdef NDEBUG
231#define EMIT_DEBUG false
232#else
233#define EMIT_DEBUG true
234#endif
235  EmitJitDebugInfo("jit-emit-debug",
236    cl::desc("Emit debug information to debugger"),
237    cl::init(EMIT_DEBUG));
238#undef EMIT_DEBUG
239
240  static cl::opt<bool>
241  EmitJitDebugInfoToDisk("jit-emit-debug-to-disk",
242    cl::Hidden,
243    cl::desc("Emit debug info objfiles to disk"),
244    cl::init(false));
245}
246
247//===----------------------------------------------------------------------===//
248// Object cache
249//
250// This object cache implementation writes cached objects to disk to the
251// directory specified by CacheDir, using a filename provided in the module
252// descriptor. The cache tries to load a saved object using that path if the
253// file exists. CacheDir defaults to "", in which case objects are cached
254// alongside their originating bitcodes.
255//
256class LLIObjectCache : public ObjectCache {
257public:
258  LLIObjectCache(const std::string& CacheDir) : CacheDir(CacheDir) {
259    // Add trailing '/' to cache dir if necessary.
260    if (!this->CacheDir.empty() &&
261        this->CacheDir[this->CacheDir.size() - 1] != '/')
262      this->CacheDir += '/';
263  }
264  virtual ~LLIObjectCache() {}
265
266  void notifyObjectCompiled(const Module *M, const MemoryBuffer *Obj) override {
267    const std::string ModuleID = M->getModuleIdentifier();
268    std::string CacheName;
269    if (!getCacheFilename(ModuleID, CacheName))
270      return;
271    std::string errStr;
272    if (!CacheDir.empty()) { // Create user-defined cache dir.
273      SmallString<128> dir(CacheName);
274      sys::path::remove_filename(dir);
275      sys::fs::create_directories(Twine(dir));
276    }
277    raw_fd_ostream outfile(CacheName.c_str(), errStr, sys::fs::F_None);
278    outfile.write(Obj->getBufferStart(), Obj->getBufferSize());
279    outfile.close();
280  }
281
282  MemoryBuffer* getObject(const Module* M) override {
283    const std::string ModuleID = M->getModuleIdentifier();
284    std::string CacheName;
285    if (!getCacheFilename(ModuleID, CacheName))
286      return nullptr;
287    // Load the object from the cache filename
288    ErrorOr<std::unique_ptr<MemoryBuffer>> IRObjectBuffer =
289        MemoryBuffer::getFile(CacheName.c_str(), -1, false);
290    // If the file isn't there, that's OK.
291    if (!IRObjectBuffer)
292      return nullptr;
293    // MCJIT will want to write into this buffer, and we don't want that
294    // because the file has probably just been mmapped.  Instead we make
295    // a copy.  The filed-based buffer will be released when it goes
296    // out of scope.
297    return MemoryBuffer::getMemBufferCopy(IRObjectBuffer.get()->getBuffer());
298  }
299
300private:
301  std::string CacheDir;
302
303  bool getCacheFilename(const std::string &ModID, std::string &CacheName) {
304    std::string Prefix("file:");
305    size_t PrefixLength = Prefix.length();
306    if (ModID.substr(0, PrefixLength) != Prefix)
307      return false;
308        std::string CacheSubdir = ModID.substr(PrefixLength);
309#if defined(_WIN32)
310        // Transform "X:\foo" => "/X\foo" for convenience.
311        if (isalpha(CacheSubdir[0]) && CacheSubdir[1] == ':') {
312          CacheSubdir[1] = CacheSubdir[0];
313          CacheSubdir[0] = '/';
314        }
315#endif
316    CacheName = CacheDir + CacheSubdir;
317    size_t pos = CacheName.rfind('.');
318    CacheName.replace(pos, CacheName.length() - pos, ".o");
319    return true;
320  }
321};
322
323static ExecutionEngine *EE = nullptr;
324static LLIObjectCache *CacheManager = nullptr;
325
326static void do_shutdown() {
327  // Cygwin-1.5 invokes DLL's dtors before atexit handler.
328#ifndef DO_NOTHING_ATEXIT
329  delete EE;
330  if (CacheManager)
331    delete CacheManager;
332  llvm_shutdown();
333#endif
334}
335
336// On Mingw and Cygwin, an external symbol named '__main' is called from the
337// generated 'main' function to allow static intialization.  To avoid linking
338// problems with remote targets (because lli's remote target support does not
339// currently handle external linking) we add a secondary module which defines
340// an empty '__main' function.
341static void addCygMingExtraModule(ExecutionEngine *EE,
342                                  LLVMContext &Context,
343                                  StringRef TargetTripleStr) {
344  IRBuilder<> Builder(Context);
345  Triple TargetTriple(TargetTripleStr);
346
347  // Create a new module.
348  Module *M = new Module("CygMingHelper", Context);
349  M->setTargetTriple(TargetTripleStr);
350
351  // Create an empty function named "__main".
352  Function *Result;
353  if (TargetTriple.isArch64Bit()) {
354    Result = Function::Create(
355      TypeBuilder<int64_t(void), false>::get(Context),
356      GlobalValue::ExternalLinkage, "__main", M);
357  } else {
358    Result = Function::Create(
359      TypeBuilder<int32_t(void), false>::get(Context),
360      GlobalValue::ExternalLinkage, "__main", M);
361  }
362  BasicBlock *BB = BasicBlock::Create(Context, "__main", Result);
363  Builder.SetInsertPoint(BB);
364  Value *ReturnVal;
365  if (TargetTriple.isArch64Bit())
366    ReturnVal = ConstantInt::get(Context, APInt(64, 0));
367  else
368    ReturnVal = ConstantInt::get(Context, APInt(32, 0));
369  Builder.CreateRet(ReturnVal);
370
371  // Add this new module to the ExecutionEngine.
372  EE->addModule(M);
373}
374
375
376//===----------------------------------------------------------------------===//
377// main Driver function
378//
379int main(int argc, char **argv, char * const *envp) {
380  sys::PrintStackTraceOnErrorSignal();
381  PrettyStackTraceProgram X(argc, argv);
382
383  LLVMContext &Context = getGlobalContext();
384  atexit(do_shutdown);  // Call llvm_shutdown() on exit.
385
386  // If we have a native target, initialize it to ensure it is linked in and
387  // usable by the JIT.
388  InitializeNativeTarget();
389  InitializeNativeTargetAsmPrinter();
390  InitializeNativeTargetAsmParser();
391
392  cl::ParseCommandLineOptions(argc, argv,
393                              "llvm interpreter & dynamic compiler\n");
394
395  // If the user doesn't want core files, disable them.
396  if (DisableCoreFiles)
397    sys::Process::PreventCoreFiles();
398
399  // Load the bitcode...
400  SMDiagnostic Err;
401  Module *Mod = ParseIRFile(InputFile, Err, Context);
402  if (!Mod) {
403    Err.print(argv[0], errs());
404    return 1;
405  }
406
407  if (EnableCacheManager) {
408    if (UseMCJIT) {
409      std::string CacheName("file:");
410      CacheName.append(InputFile);
411      Mod->setModuleIdentifier(CacheName);
412    } else
413      errs() << "warning: -enable-cache-manager can only be used with MCJIT.";
414  }
415
416  // If not jitting lazily, load the whole bitcode file eagerly too.
417  if (NoLazyCompilation) {
418    if (std::error_code EC = Mod->materializeAllPermanently()) {
419      errs() << argv[0] << ": bitcode didn't read correctly.\n";
420      errs() << "Reason: " << EC.message() << "\n";
421      exit(1);
422    }
423  }
424
425  if (DebugIR) {
426    if (!UseMCJIT) {
427      errs() << "warning: -debug-ir used without -use-mcjit. Only partial debug"
428        << " information will be emitted by the non-MC JIT engine. To see full"
429        << " source debug information, enable the flag '-use-mcjit'.\n";
430
431    }
432    ModulePass *DebugIRPass = createDebugIRPass();
433    DebugIRPass->runOnModule(*Mod);
434  }
435
436  std::string ErrorMsg;
437  EngineBuilder builder(Mod);
438  builder.setMArch(MArch);
439  builder.setMCPU(MCPU);
440  builder.setMAttrs(MAttrs);
441  builder.setRelocationModel(RelocModel);
442  builder.setCodeModel(CMModel);
443  builder.setErrorStr(&ErrorMsg);
444  builder.setEngineKind(ForceInterpreter
445                        ? EngineKind::Interpreter
446                        : EngineKind::JIT);
447
448  // If we are supposed to override the target triple, do so now.
449  if (!TargetTriple.empty())
450    Mod->setTargetTriple(Triple::normalize(TargetTriple));
451
452  // Enable MCJIT if desired.
453  RTDyldMemoryManager *RTDyldMM = nullptr;
454  if (UseMCJIT && !ForceInterpreter) {
455    builder.setUseMCJIT(true);
456    if (RemoteMCJIT)
457      RTDyldMM = new RemoteMemoryManager();
458    else
459      RTDyldMM = new SectionMemoryManager();
460    builder.setMCJITMemoryManager(RTDyldMM);
461  } else {
462    if (RemoteMCJIT) {
463      errs() << "error: Remote process execution requires -use-mcjit\n";
464      exit(1);
465    }
466    builder.setJITMemoryManager(ForceInterpreter ? nullptr :
467                                JITMemoryManager::CreateDefaultMemManager());
468  }
469
470  CodeGenOpt::Level OLvl = CodeGenOpt::Default;
471  switch (OptLevel) {
472  default:
473    errs() << argv[0] << ": invalid optimization level.\n";
474    return 1;
475  case ' ': break;
476  case '0': OLvl = CodeGenOpt::None; break;
477  case '1': OLvl = CodeGenOpt::Less; break;
478  case '2': OLvl = CodeGenOpt::Default; break;
479  case '3': OLvl = CodeGenOpt::Aggressive; break;
480  }
481  builder.setOptLevel(OLvl);
482
483  TargetOptions Options;
484  Options.UseSoftFloat = GenerateSoftFloatCalls;
485  if (FloatABIForCalls != FloatABI::Default)
486    Options.FloatABIType = FloatABIForCalls;
487  if (GenerateSoftFloatCalls)
488    FloatABIForCalls = FloatABI::Soft;
489
490  // Remote target execution doesn't handle EH or debug registration.
491  if (!RemoteMCJIT) {
492    Options.JITEmitDebugInfo = EmitJitDebugInfo;
493    Options.JITEmitDebugInfoToDisk = EmitJitDebugInfoToDisk;
494  }
495
496  builder.setTargetOptions(Options);
497
498  EE = builder.create();
499  if (!EE) {
500    if (!ErrorMsg.empty())
501      errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
502    else
503      errs() << argv[0] << ": unknown error creating EE!\n";
504    exit(1);
505  }
506
507  if (EnableCacheManager) {
508    CacheManager = new LLIObjectCache(ObjectCacheDir);
509    EE->setObjectCache(CacheManager);
510  }
511
512  // Load any additional modules specified on the command line.
513  for (unsigned i = 0, e = ExtraModules.size(); i != e; ++i) {
514    Module *XMod = ParseIRFile(ExtraModules[i], Err, Context);
515    if (!XMod) {
516      Err.print(argv[0], errs());
517      return 1;
518    }
519    if (EnableCacheManager) {
520      if (UseMCJIT) {
521        std::string CacheName("file:");
522        CacheName.append(ExtraModules[i]);
523        XMod->setModuleIdentifier(CacheName);
524      }
525      // else, we already printed a warning above.
526    }
527    EE->addModule(XMod);
528  }
529
530  for (unsigned i = 0, e = ExtraObjects.size(); i != e; ++i) {
531    ErrorOr<object::ObjectFile *> Obj =
532        object::ObjectFile::createObjectFile(ExtraObjects[i]);
533    if (!Obj) {
534      Err.print(argv[0], errs());
535      return 1;
536    }
537    EE->addObjectFile(std::unique_ptr<object::ObjectFile>(Obj.get()));
538  }
539
540  for (unsigned i = 0, e = ExtraArchives.size(); i != e; ++i) {
541    ErrorOr<std::unique_ptr<MemoryBuffer>> ArBuf =
542        MemoryBuffer::getFileOrSTDIN(ExtraArchives[i]);
543    if (!ArBuf) {
544      Err.print(argv[0], errs());
545      return 1;
546    }
547    std::error_code EC;
548    object::Archive *Ar = new object::Archive(std::move(ArBuf.get()), EC);
549    if (EC || !Ar) {
550      Err.print(argv[0], errs());
551      return 1;
552    }
553    EE->addArchive(Ar);
554  }
555
556  // If the target is Cygwin/MingW and we are generating remote code, we
557  // need an extra module to help out with linking.
558  if (RemoteMCJIT && Triple(Mod->getTargetTriple()).isOSCygMing()) {
559    addCygMingExtraModule(EE, Context, Mod->getTargetTriple());
560  }
561
562  // The following functions have no effect if their respective profiling
563  // support wasn't enabled in the build configuration.
564  EE->RegisterJITEventListener(
565                JITEventListener::createOProfileJITEventListener());
566  EE->RegisterJITEventListener(
567                JITEventListener::createIntelJITEventListener());
568
569  if (!NoLazyCompilation && RemoteMCJIT) {
570    errs() << "warning: remote mcjit does not support lazy compilation\n";
571    NoLazyCompilation = true;
572  }
573  EE->DisableLazyCompilation(NoLazyCompilation);
574
575  // If the user specifically requested an argv[0] to pass into the program,
576  // do it now.
577  if (!FakeArgv0.empty()) {
578    InputFile = FakeArgv0;
579  } else {
580    // Otherwise, if there is a .bc suffix on the executable strip it off, it
581    // might confuse the program.
582    if (StringRef(InputFile).endswith(".bc"))
583      InputFile.erase(InputFile.length() - 3);
584  }
585
586  // Add the module's name to the start of the vector of arguments to main().
587  InputArgv.insert(InputArgv.begin(), InputFile);
588
589  // Call the main function from M as if its signature were:
590  //   int main (int argc, char **argv, const char **envp)
591  // using the contents of Args to determine argc & argv, and the contents of
592  // EnvVars to determine envp.
593  //
594  Function *EntryFn = Mod->getFunction(EntryFunc);
595  if (!EntryFn) {
596    errs() << '\'' << EntryFunc << "\' function not found in module.\n";
597    return -1;
598  }
599
600  // Reset errno to zero on entry to main.
601  errno = 0;
602
603  int Result;
604
605  if (!RemoteMCJIT) {
606    // If the program doesn't explicitly call exit, we will need the Exit
607    // function later on to make an explicit call, so get the function now.
608    Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
609                                                      Type::getInt32Ty(Context),
610                                                      NULL);
611
612    // Run static constructors.
613    if (UseMCJIT && !ForceInterpreter) {
614      // Give MCJIT a chance to apply relocations and set page permissions.
615      EE->finalizeObject();
616    }
617    EE->runStaticConstructorsDestructors(false);
618
619    if (!UseMCJIT && 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    // Trigger compilation separately so code regions that need to be
628    // invalidated will be known.
629    (void)EE->getPointerToFunction(EntryFn);
630    // Clear instruction cache before code will be executed.
631    if (RTDyldMM)
632      static_cast<SectionMemoryManager*>(RTDyldMM)->invalidateInstructionCache();
633
634    // Run main.
635    Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
636
637    // Run static destructors.
638    EE->runStaticConstructorsDestructors(true);
639
640    // If the program didn't call exit explicitly, we should call it now.
641    // This ensures that any atexit handlers get called correctly.
642    if (Function *ExitF = dyn_cast<Function>(Exit)) {
643      std::vector<GenericValue> Args;
644      GenericValue ResultGV;
645      ResultGV.IntVal = APInt(32, Result);
646      Args.push_back(ResultGV);
647      EE->runFunction(ExitF, Args);
648      errs() << "ERROR: exit(" << Result << ") returned!\n";
649      abort();
650    } else {
651      errs() << "ERROR: exit defined with wrong prototype!\n";
652      abort();
653    }
654  } else {
655    // else == "if (RemoteMCJIT)"
656
657    // Remote target MCJIT doesn't (yet) support static constructors. No reason
658    // it couldn't. This is a limitation of the LLI implemantation, not the
659    // MCJIT itself. FIXME.
660    //
661    RemoteMemoryManager *MM = static_cast<RemoteMemoryManager*>(RTDyldMM);
662    // Everything is prepared now, so lay out our program for the target
663    // address space, assign the section addresses to resolve any relocations,
664    // and send it to the target.
665
666    std::unique_ptr<RemoteTarget> Target;
667    if (!ChildExecPath.empty()) { // Remote execution on a child process
668#ifndef LLVM_ON_UNIX
669      // FIXME: Remove this pointless fallback mode which causes tests to "pass"
670      // on platforms where they should XFAIL.
671      errs() << "Warning: host does not support external remote targets.\n"
672             << "  Defaulting to simulated remote execution\n";
673      Target.reset(new RemoteTarget);
674#else
675      if (!sys::fs::can_execute(ChildExecPath)) {
676        errs() << "Unable to find usable child executable: '" << ChildExecPath
677               << "'\n";
678        return -1;
679      }
680      Target.reset(new RemoteTargetExternal(ChildExecPath));
681#endif
682    } else {
683      // No child process name provided, use simulated remote execution.
684      Target.reset(new RemoteTarget);
685    }
686
687    // Give the memory manager a pointer to our remote target interface object.
688    MM->setRemoteTarget(Target.get());
689
690    // Create the remote target.
691    if (!Target->create()) {
692      errs() << "ERROR: " << Target->getErrorMsg() << "\n";
693      return EXIT_FAILURE;
694    }
695
696    // Since we're executing in a (at least simulated) remote address space,
697    // we can't use the ExecutionEngine::runFunctionAsMain(). We have to
698    // grab the function address directly here and tell the remote target
699    // to execute the function.
700    //
701    // Our memory manager will map generated code into the remote address
702    // space as it is loaded and copy the bits over during the finalizeMemory
703    // operation.
704    //
705    // FIXME: argv and envp handling.
706    uint64_t Entry = EE->getFunctionAddress(EntryFn->getName().str());
707
708    DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
709                 << format("%llx", Entry) << "\n");
710
711    if (!Target->executeCode(Entry, Result))
712      errs() << "ERROR: " << Target->getErrorMsg() << "\n";
713
714    // Like static constructors, the remote target MCJIT support doesn't handle
715    // this yet. It could. FIXME.
716
717    // Stop the remote target
718    Target->stop();
719  }
720
721  return Result;
722}
723