MCJIT.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- MCJIT.cpp - MC-based Just-in-Time 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#include "MCJIT.h"
11#include "llvm/ExecutionEngine/GenericValue.h"
12#include "llvm/ExecutionEngine/JITEventListener.h"
13#include "llvm/ExecutionEngine/JITMemoryManager.h"
14#include "llvm/ExecutionEngine/MCJIT.h"
15#include "llvm/ExecutionEngine/ObjectBuffer.h"
16#include "llvm/ExecutionEngine/ObjectImage.h"
17#include "llvm/ExecutionEngine/SectionMemoryManager.h"
18#include "llvm/IR/DataLayout.h"
19#include "llvm/IR/DerivedTypes.h"
20#include "llvm/IR/Function.h"
21#include "llvm/IR/Mangler.h"
22#include "llvm/IR/Module.h"
23#include "llvm/MC/MCAsmInfo.h"
24#include "llvm/Object/Archive.h"
25#include "llvm/PassManager.h"
26#include "llvm/Support/DynamicLibrary.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/MemoryBuffer.h"
29#include "llvm/Support/MutexGuard.h"
30#include "llvm/Target/TargetLowering.h"
31
32using namespace llvm;
33
34namespace {
35
36static struct RegisterJIT {
37  RegisterJIT() { MCJIT::Register(); }
38} JITRegistrator;
39
40}
41
42extern "C" void LLVMLinkInMCJIT() {
43}
44
45ExecutionEngine *MCJIT::createJIT(Module *M,
46                                  std::string *ErrorStr,
47                                  RTDyldMemoryManager *MemMgr,
48                                  bool GVsWithCode,
49                                  TargetMachine *TM) {
50  // Try to register the program as a source of symbols to resolve against.
51  //
52  // FIXME: Don't do this here.
53  sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
54
55  return new MCJIT(M, TM, MemMgr ? MemMgr : new SectionMemoryManager(),
56                   GVsWithCode);
57}
58
59MCJIT::MCJIT(Module *m, TargetMachine *tm, RTDyldMemoryManager *MM,
60             bool AllocateGVsWithCode)
61  : ExecutionEngine(m), TM(tm), Ctx(0), MemMgr(this, MM), Dyld(&MemMgr),
62    ObjCache(0) {
63
64  OwnedModules.addModule(m);
65  setDataLayout(TM->getDataLayout());
66}
67
68MCJIT::~MCJIT() {
69  MutexGuard locked(lock);
70  // FIXME: We are managing our modules, so we do not want the base class
71  // ExecutionEngine to manage them as well. To avoid double destruction
72  // of the first (and only) module added in ExecutionEngine constructor
73  // we remove it from EE and will destruct it ourselves.
74  //
75  // It may make sense to move our module manager (based on SmallStPtr) back
76  // into EE if the JIT and Interpreter can live with it.
77  // If so, additional functions: addModule, removeModule, FindFunctionNamed,
78  // runStaticConstructorsDestructors could be moved back to EE as well.
79  //
80  Modules.clear();
81  Dyld.deregisterEHFrames();
82
83  LoadedObjectList::iterator it, end;
84  for (it = LoadedObjects.begin(), end = LoadedObjects.end(); it != end; ++it) {
85    ObjectImage *Obj = *it;
86    if (Obj) {
87      NotifyFreeingObject(*Obj);
88      delete Obj;
89    }
90  }
91  LoadedObjects.clear();
92
93
94  SmallVector<object::Archive *, 2>::iterator ArIt, ArEnd;
95  for (ArIt = Archives.begin(), ArEnd = Archives.end(); ArIt != ArEnd; ++ArIt) {
96    object::Archive *A = *ArIt;
97    delete A;
98  }
99  Archives.clear();
100
101  delete TM;
102}
103
104void MCJIT::addModule(Module *M) {
105  MutexGuard locked(lock);
106  OwnedModules.addModule(M);
107}
108
109bool MCJIT::removeModule(Module *M) {
110  MutexGuard locked(lock);
111  return OwnedModules.removeModule(M);
112}
113
114
115
116void MCJIT::addObjectFile(object::ObjectFile *Obj) {
117  ObjectImage *LoadedObject = Dyld.loadObject(Obj);
118  if (!LoadedObject || Dyld.hasError())
119    report_fatal_error(Dyld.getErrorString());
120
121  LoadedObjects.push_back(LoadedObject);
122
123  NotifyObjectEmitted(*LoadedObject);
124}
125
126void MCJIT::addArchive(object::Archive *A) {
127  Archives.push_back(A);
128}
129
130
131void MCJIT::setObjectCache(ObjectCache* NewCache) {
132  MutexGuard locked(lock);
133  ObjCache = NewCache;
134}
135
136ObjectBufferStream* MCJIT::emitObject(Module *M) {
137  MutexGuard locked(lock);
138
139  // This must be a module which has already been added but not loaded to this
140  // MCJIT instance, since these conditions are tested by our caller,
141  // generateCodeForModule.
142
143  PassManager PM;
144
145  M->setDataLayout(TM->getDataLayout());
146  PM.add(new DataLayoutPass(M));
147
148  // The RuntimeDyld will take ownership of this shortly
149  std::unique_ptr<ObjectBufferStream> CompiledObject(new ObjectBufferStream());
150
151  // Turn the machine code intermediate representation into bytes in memory
152  // that may be executed.
153  if (TM->addPassesToEmitMC(PM, Ctx, CompiledObject->getOStream(), false)) {
154    report_fatal_error("Target does not support MC emission!");
155  }
156
157  // Initialize passes.
158  PM.run(*M);
159  // Flush the output buffer to get the generated code into memory
160  CompiledObject->flush();
161
162  // If we have an object cache, tell it about the new object.
163  // Note that we're using the compiled image, not the loaded image (as below).
164  if (ObjCache) {
165    // MemoryBuffer is a thin wrapper around the actual memory, so it's OK
166    // to create a temporary object here and delete it after the call.
167    std::unique_ptr<MemoryBuffer> MB(CompiledObject->getMemBuffer());
168    ObjCache->notifyObjectCompiled(M, MB.get());
169  }
170
171  return CompiledObject.release();
172}
173
174void MCJIT::generateCodeForModule(Module *M) {
175  // Get a thread lock to make sure we aren't trying to load multiple times
176  MutexGuard locked(lock);
177
178  // This must be a module which has already been added to this MCJIT instance.
179  assert(OwnedModules.ownsModule(M) &&
180         "MCJIT::generateCodeForModule: Unknown module.");
181
182  // Re-compilation is not supported
183  if (OwnedModules.hasModuleBeenLoaded(M))
184    return;
185
186  std::unique_ptr<ObjectBuffer> ObjectToLoad;
187  // Try to load the pre-compiled object from cache if possible
188  if (0 != ObjCache) {
189    std::unique_ptr<MemoryBuffer> PreCompiledObject(ObjCache->getObject(M));
190    if (0 != PreCompiledObject.get())
191      ObjectToLoad.reset(new ObjectBuffer(PreCompiledObject.release()));
192  }
193
194  // If the cache did not contain a suitable object, compile the object
195  if (!ObjectToLoad) {
196    ObjectToLoad.reset(emitObject(M));
197    assert(ObjectToLoad.get() && "Compilation did not produce an object.");
198  }
199
200  // Load the object into the dynamic linker.
201  // MCJIT now owns the ObjectImage pointer (via its LoadedObjects list).
202  ObjectImage *LoadedObject = Dyld.loadObject(ObjectToLoad.release());
203  LoadedObjects.push_back(LoadedObject);
204  if (!LoadedObject)
205    report_fatal_error(Dyld.getErrorString());
206
207  // FIXME: Make this optional, maybe even move it to a JIT event listener
208  LoadedObject->registerWithDebugger();
209
210  NotifyObjectEmitted(*LoadedObject);
211
212  OwnedModules.markModuleAsLoaded(M);
213}
214
215void MCJIT::finalizeLoadedModules() {
216  MutexGuard locked(lock);
217
218  // Resolve any outstanding relocations.
219  Dyld.resolveRelocations();
220
221  OwnedModules.markAllLoadedModulesAsFinalized();
222
223  // Register EH frame data for any module we own which has been loaded
224  Dyld.registerEHFrames();
225
226  // Set page permissions.
227  MemMgr.finalizeMemory();
228}
229
230// FIXME: Rename this.
231void MCJIT::finalizeObject() {
232  MutexGuard locked(lock);
233
234  for (ModulePtrSet::iterator I = OwnedModules.begin_added(),
235                              E = OwnedModules.end_added();
236       I != E; ++I) {
237    Module *M = *I;
238    generateCodeForModule(M);
239  }
240
241  finalizeLoadedModules();
242}
243
244void MCJIT::finalizeModule(Module *M) {
245  MutexGuard locked(lock);
246
247  // This must be a module which has already been added to this MCJIT instance.
248  assert(OwnedModules.ownsModule(M) && "MCJIT::finalizeModule: Unknown module.");
249
250  // If the module hasn't been compiled, just do that.
251  if (!OwnedModules.hasModuleBeenLoaded(M))
252    generateCodeForModule(M);
253
254  finalizeLoadedModules();
255}
256
257void *MCJIT::getPointerToBasicBlock(BasicBlock *BB) {
258  report_fatal_error("not yet implemented");
259}
260
261uint64_t MCJIT::getExistingSymbolAddress(const std::string &Name) {
262  Mangler Mang(TM->getDataLayout());
263  SmallString<128> FullName;
264  Mang.getNameWithPrefix(FullName, Name);
265  return Dyld.getSymbolLoadAddress(FullName);
266}
267
268Module *MCJIT::findModuleForSymbol(const std::string &Name,
269                                   bool CheckFunctionsOnly) {
270  MutexGuard locked(lock);
271
272  // If it hasn't already been generated, see if it's in one of our modules.
273  for (ModulePtrSet::iterator I = OwnedModules.begin_added(),
274                              E = OwnedModules.end_added();
275       I != E; ++I) {
276    Module *M = *I;
277    Function *F = M->getFunction(Name);
278    if (F && !F->isDeclaration())
279      return M;
280    if (!CheckFunctionsOnly) {
281      GlobalVariable *G = M->getGlobalVariable(Name);
282      if (G && !G->isDeclaration())
283        return M;
284      // FIXME: Do we need to worry about global aliases?
285    }
286  }
287  // We didn't find the symbol in any of our modules.
288  return NULL;
289}
290
291uint64_t MCJIT::getSymbolAddress(const std::string &Name,
292                                 bool CheckFunctionsOnly)
293{
294  MutexGuard locked(lock);
295
296  // First, check to see if we already have this symbol.
297  uint64_t Addr = getExistingSymbolAddress(Name);
298  if (Addr)
299    return Addr;
300
301  SmallVector<object::Archive*, 2>::iterator I, E;
302  for (I = Archives.begin(), E = Archives.end(); I != E; ++I) {
303    object::Archive *A = *I;
304    // Look for our symbols in each Archive
305    object::Archive::child_iterator ChildIt = A->findSym(Name);
306    if (ChildIt != A->child_end()) {
307      std::unique_ptr<object::Binary> ChildBin;
308      // FIXME: Support nested archives?
309      if (!ChildIt->getAsBinary(ChildBin) && ChildBin->isObject()) {
310        object::ObjectFile *OF = reinterpret_cast<object::ObjectFile *>(
311                                                            ChildBin.release());
312        // This causes the object file to be loaded.
313        addObjectFile(OF);
314        // The address should be here now.
315        Addr = getExistingSymbolAddress(Name);
316        if (Addr)
317          return Addr;
318      }
319    }
320  }
321
322  // If it hasn't already been generated, see if it's in one of our modules.
323  Module *M = findModuleForSymbol(Name, CheckFunctionsOnly);
324  if (!M)
325    return 0;
326
327  generateCodeForModule(M);
328
329  // Check the RuntimeDyld table again, it should be there now.
330  return getExistingSymbolAddress(Name);
331}
332
333uint64_t MCJIT::getGlobalValueAddress(const std::string &Name) {
334  MutexGuard locked(lock);
335  uint64_t Result = getSymbolAddress(Name, false);
336  if (Result != 0)
337    finalizeLoadedModules();
338  return Result;
339}
340
341uint64_t MCJIT::getFunctionAddress(const std::string &Name) {
342  MutexGuard locked(lock);
343  uint64_t Result = getSymbolAddress(Name, true);
344  if (Result != 0)
345    finalizeLoadedModules();
346  return Result;
347}
348
349// Deprecated.  Use getFunctionAddress instead.
350void *MCJIT::getPointerToFunction(Function *F) {
351  MutexGuard locked(lock);
352
353  if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
354    bool AbortOnFailure = !F->hasExternalWeakLinkage();
355    void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
356    addGlobalMapping(F, Addr);
357    return Addr;
358  }
359
360  Module *M = F->getParent();
361  bool HasBeenAddedButNotLoaded = OwnedModules.hasModuleBeenAddedButNotLoaded(M);
362
363  // Make sure the relevant module has been compiled and loaded.
364  if (HasBeenAddedButNotLoaded)
365    generateCodeForModule(M);
366  else if (!OwnedModules.hasModuleBeenLoaded(M))
367    // If this function doesn't belong to one of our modules, we're done.
368    return NULL;
369
370  // FIXME: Should the Dyld be retaining module information? Probably not.
371  //
372  // This is the accessor for the target address, so make sure to check the
373  // load address of the symbol, not the local address.
374  Mangler Mang(TM->getDataLayout());
375  SmallString<128> Name;
376  TM->getNameWithPrefix(Name, F, Mang);
377  return (void*)Dyld.getSymbolLoadAddress(Name);
378}
379
380void *MCJIT::recompileAndRelinkFunction(Function *F) {
381  report_fatal_error("not yet implemented");
382}
383
384void MCJIT::freeMachineCodeForFunction(Function *F) {
385  report_fatal_error("not yet implemented");
386}
387
388void MCJIT::runStaticConstructorsDestructorsInModulePtrSet(
389    bool isDtors, ModulePtrSet::iterator I, ModulePtrSet::iterator E) {
390  for (; I != E; ++I) {
391    ExecutionEngine::runStaticConstructorsDestructors(*I, isDtors);
392  }
393}
394
395void MCJIT::runStaticConstructorsDestructors(bool isDtors) {
396  // Execute global ctors/dtors for each module in the program.
397  runStaticConstructorsDestructorsInModulePtrSet(
398      isDtors, OwnedModules.begin_added(), OwnedModules.end_added());
399  runStaticConstructorsDestructorsInModulePtrSet(
400      isDtors, OwnedModules.begin_loaded(), OwnedModules.end_loaded());
401  runStaticConstructorsDestructorsInModulePtrSet(
402      isDtors, OwnedModules.begin_finalized(), OwnedModules.end_finalized());
403}
404
405Function *MCJIT::FindFunctionNamedInModulePtrSet(const char *FnName,
406                                                 ModulePtrSet::iterator I,
407                                                 ModulePtrSet::iterator E) {
408  for (; I != E; ++I) {
409    if (Function *F = (*I)->getFunction(FnName))
410      return F;
411  }
412  return 0;
413}
414
415Function *MCJIT::FindFunctionNamed(const char *FnName) {
416  Function *F = FindFunctionNamedInModulePtrSet(
417      FnName, OwnedModules.begin_added(), OwnedModules.end_added());
418  if (!F)
419    F = FindFunctionNamedInModulePtrSet(FnName, OwnedModules.begin_loaded(),
420                                        OwnedModules.end_loaded());
421  if (!F)
422    F = FindFunctionNamedInModulePtrSet(FnName, OwnedModules.begin_finalized(),
423                                        OwnedModules.end_finalized());
424  return F;
425}
426
427GenericValue MCJIT::runFunction(Function *F,
428                                const std::vector<GenericValue> &ArgValues) {
429  assert(F && "Function *F was null at entry to run()");
430
431  void *FPtr = getPointerToFunction(F);
432  assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
433  FunctionType *FTy = F->getFunctionType();
434  Type *RetTy = FTy->getReturnType();
435
436  assert((FTy->getNumParams() == ArgValues.size() ||
437          (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
438         "Wrong number of arguments passed into function!");
439  assert(FTy->getNumParams() == ArgValues.size() &&
440         "This doesn't support passing arguments through varargs (yet)!");
441
442  // Handle some common cases first.  These cases correspond to common `main'
443  // prototypes.
444  if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
445    switch (ArgValues.size()) {
446    case 3:
447      if (FTy->getParamType(0)->isIntegerTy(32) &&
448          FTy->getParamType(1)->isPointerTy() &&
449          FTy->getParamType(2)->isPointerTy()) {
450        int (*PF)(int, char **, const char **) =
451          (int(*)(int, char **, const char **))(intptr_t)FPtr;
452
453        // Call the function.
454        GenericValue rv;
455        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
456                                 (char **)GVTOP(ArgValues[1]),
457                                 (const char **)GVTOP(ArgValues[2])));
458        return rv;
459      }
460      break;
461    case 2:
462      if (FTy->getParamType(0)->isIntegerTy(32) &&
463          FTy->getParamType(1)->isPointerTy()) {
464        int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
465
466        // Call the function.
467        GenericValue rv;
468        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
469                                 (char **)GVTOP(ArgValues[1])));
470        return rv;
471      }
472      break;
473    case 1:
474      if (FTy->getNumParams() == 1 &&
475          FTy->getParamType(0)->isIntegerTy(32)) {
476        GenericValue rv;
477        int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
478        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
479        return rv;
480      }
481      break;
482    }
483  }
484
485  // Handle cases where no arguments are passed first.
486  if (ArgValues.empty()) {
487    GenericValue rv;
488    switch (RetTy->getTypeID()) {
489    default: llvm_unreachable("Unknown return type for function call!");
490    case Type::IntegerTyID: {
491      unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
492      if (BitWidth == 1)
493        rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
494      else if (BitWidth <= 8)
495        rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
496      else if (BitWidth <= 16)
497        rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
498      else if (BitWidth <= 32)
499        rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
500      else if (BitWidth <= 64)
501        rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
502      else
503        llvm_unreachable("Integer types > 64 bits not supported");
504      return rv;
505    }
506    case Type::VoidTyID:
507      rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
508      return rv;
509    case Type::FloatTyID:
510      rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
511      return rv;
512    case Type::DoubleTyID:
513      rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
514      return rv;
515    case Type::X86_FP80TyID:
516    case Type::FP128TyID:
517    case Type::PPC_FP128TyID:
518      llvm_unreachable("long double not supported yet");
519    case Type::PointerTyID:
520      return PTOGV(((void*(*)())(intptr_t)FPtr)());
521    }
522  }
523
524  llvm_unreachable("Full-featured argument passing not supported yet!");
525}
526
527void *MCJIT::getPointerToNamedFunction(const std::string &Name,
528                                       bool AbortOnFailure) {
529  if (!isSymbolSearchingDisabled()) {
530    void *ptr = MemMgr.getPointerToNamedFunction(Name, false);
531    if (ptr)
532      return ptr;
533  }
534
535  /// If a LazyFunctionCreator is installed, use it to get/create the function.
536  if (LazyFunctionCreator)
537    if (void *RP = LazyFunctionCreator(Name))
538      return RP;
539
540  if (AbortOnFailure) {
541    report_fatal_error("Program used external function '"+Name+
542                       "' which could not be resolved!");
543  }
544  return 0;
545}
546
547void MCJIT::RegisterJITEventListener(JITEventListener *L) {
548  if (L == NULL)
549    return;
550  MutexGuard locked(lock);
551  EventListeners.push_back(L);
552}
553void MCJIT::UnregisterJITEventListener(JITEventListener *L) {
554  if (L == NULL)
555    return;
556  MutexGuard locked(lock);
557  SmallVector<JITEventListener*, 2>::reverse_iterator I=
558      std::find(EventListeners.rbegin(), EventListeners.rend(), L);
559  if (I != EventListeners.rend()) {
560    std::swap(*I, EventListeners.back());
561    EventListeners.pop_back();
562  }
563}
564void MCJIT::NotifyObjectEmitted(const ObjectImage& Obj) {
565  MutexGuard locked(lock);
566  MemMgr.notifyObjectLoaded(this, &Obj);
567  for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
568    EventListeners[I]->NotifyObjectEmitted(Obj);
569  }
570}
571void MCJIT::NotifyFreeingObject(const ObjectImage& Obj) {
572  MutexGuard locked(lock);
573  for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
574    EventListeners[I]->NotifyFreeingObject(Obj);
575  }
576}
577
578uint64_t LinkingMemoryManager::getSymbolAddress(const std::string &Name) {
579  uint64_t Result = ParentEngine->getSymbolAddress(Name, false);
580  // If the symbols wasn't found and it begins with an underscore, try again
581  // without the underscore.
582  if (!Result && Name[0] == '_')
583    Result = ParentEngine->getSymbolAddress(Name.substr(1), false);
584  if (Result)
585    return Result;
586  return ClientMM->getSymbolAddress(Name);
587}
588