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/MC/MCAsmInfo.h"
22#include "llvm/Support/DynamicLibrary.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include "llvm/Support/MutexGuard.h"
26
27using namespace llvm;
28
29namespace {
30
31static struct RegisterJIT {
32  RegisterJIT() { MCJIT::Register(); }
33} JITRegistrator;
34
35}
36
37extern "C" void LLVMLinkInMCJIT() {
38}
39
40ExecutionEngine *MCJIT::createJIT(Module *M,
41                                  std::string *ErrorStr,
42                                  RTDyldMemoryManager *MemMgr,
43                                  bool GVsWithCode,
44                                  TargetMachine *TM) {
45  // Try to register the program as a source of symbols to resolve against.
46  //
47  // FIXME: Don't do this here.
48  sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
49
50  return new MCJIT(M, TM, MemMgr ? MemMgr : new SectionMemoryManager(),
51                   GVsWithCode);
52}
53
54MCJIT::MCJIT(Module *m, TargetMachine *tm, RTDyldMemoryManager *MM,
55             bool AllocateGVsWithCode)
56  : ExecutionEngine(m), TM(tm), Ctx(0), MemMgr(MM), Dyld(MM),
57    IsLoaded(false), M(m), ObjCache(0) {
58
59  setDataLayout(TM->getDataLayout());
60}
61
62MCJIT::~MCJIT() {
63  if (LoadedObject)
64    NotifyFreeingObject(*LoadedObject.get());
65  delete MemMgr;
66  delete TM;
67}
68
69void MCJIT::setObjectCache(ObjectCache* NewCache) {
70  ObjCache = NewCache;
71}
72
73ObjectBufferStream* MCJIT::emitObject(Module *m) {
74  /// Currently, MCJIT only supports a single module and the module passed to
75  /// this function call is expected to be the contained module.  The module
76  /// is passed as a parameter here to prepare for multiple module support in
77  /// the future.
78  assert(M == m);
79
80  // Get a thread lock to make sure we aren't trying to compile multiple times
81  MutexGuard locked(lock);
82
83  // FIXME: Track compilation state on a per-module basis when multiple modules
84  //        are supported.
85  // Re-compilation is not supported
86  assert(!IsLoaded);
87
88  PassManager PM;
89
90  PM.add(new DataLayout(*TM->getDataLayout()));
91
92  // The RuntimeDyld will take ownership of this shortly
93  OwningPtr<ObjectBufferStream> CompiledObject(new ObjectBufferStream());
94
95  // Turn the machine code intermediate representation into bytes in memory
96  // that may be executed.
97  if (TM->addPassesToEmitMC(PM, Ctx, CompiledObject->getOStream(), false)) {
98    report_fatal_error("Target does not support MC emission!");
99  }
100
101  // Initialize passes.
102  PM.run(*m);
103  // Flush the output buffer to get the generated code into memory
104  CompiledObject->flush();
105
106  // If we have an object cache, tell it about the new object.
107  // Note that we're using the compiled image, not the loaded image (as below).
108  if (ObjCache) {
109    // MemoryBuffer is a thin wrapper around the actual memory, so it's OK
110    // to create a temporary object here and delete it after the call.
111    OwningPtr<MemoryBuffer> MB(CompiledObject->getMemBuffer());
112    ObjCache->notifyObjectCompiled(m, MB.get());
113  }
114
115  return CompiledObject.take();
116}
117
118void MCJIT::loadObject(Module *M) {
119
120  // Get a thread lock to make sure we aren't trying to load multiple times
121  MutexGuard locked(lock);
122
123  // FIXME: Track compilation state on a per-module basis when multiple modules
124  //        are supported.
125  // Re-compilation is not supported
126  if (IsLoaded)
127    return;
128
129  OwningPtr<ObjectBuffer> ObjectToLoad;
130  // Try to load the pre-compiled object from cache if possible
131  if (0 != ObjCache) {
132    OwningPtr<MemoryBuffer> PreCompiledObject(ObjCache->getObject(M));
133    if (0 != PreCompiledObject.get())
134      ObjectToLoad.reset(new ObjectBuffer(PreCompiledObject.take()));
135  }
136
137  // If the cache did not contain a suitable object, compile the object
138  if (!ObjectToLoad) {
139    ObjectToLoad.reset(emitObject(M));
140    assert(ObjectToLoad.get() && "Compilation did not produce an object.");
141  }
142
143  // Load the object into the dynamic linker.
144  // handing off ownership of the buffer
145  LoadedObject.reset(Dyld.loadObject(ObjectToLoad.take()));
146  if (!LoadedObject)
147    report_fatal_error(Dyld.getErrorString());
148
149  // Resolve any relocations.
150  Dyld.resolveRelocations();
151
152  // FIXME: Make this optional, maybe even move it to a JIT event listener
153  LoadedObject->registerWithDebugger();
154
155  NotifyObjectEmitted(*LoadedObject);
156
157  // FIXME: Add support for per-module compilation state
158  IsLoaded = true;
159}
160
161// FIXME: Add a parameter to identify which object is being finalized when
162// MCJIT supports multiple modules.
163// FIXME: Provide a way to separate code emission, relocations and page
164// protection in the interface.
165void MCJIT::finalizeObject() {
166  // If the module hasn't been compiled, just do that.
167  if (!IsLoaded) {
168    // If the call to Dyld.resolveRelocations() is removed from loadObject()
169    // we'll need to do that here.
170    loadObject(M);
171  } else {
172    // Resolve any relocations.
173    Dyld.resolveRelocations();
174  }
175
176  StringRef EHData = Dyld.getEHFrameSection();
177  if (!EHData.empty())
178    MemMgr->registerEHFrames(EHData);
179
180  // Set page permissions.
181  MemMgr->finalizeMemory();
182}
183
184void *MCJIT::getPointerToBasicBlock(BasicBlock *BB) {
185  report_fatal_error("not yet implemented");
186}
187
188void *MCJIT::getPointerToFunction(Function *F) {
189  // FIXME: This should really return a uint64_t since it's a pointer in the
190  // target address space, not our local address space. That's part of the
191  // ExecutionEngine interface, though. Fix that when the old JIT finally
192  // dies.
193
194  // FIXME: Add support for per-module compilation state
195  if (!IsLoaded)
196    loadObject(M);
197
198  if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
199    bool AbortOnFailure = !F->hasExternalWeakLinkage();
200    void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
201    addGlobalMapping(F, Addr);
202    return Addr;
203  }
204
205  // FIXME: Should the Dyld be retaining module information? Probably not.
206  // FIXME: Should we be using the mangler for this? Probably.
207  //
208  // This is the accessor for the target address, so make sure to check the
209  // load address of the symbol, not the local address.
210  StringRef BaseName = F->getName();
211  if (BaseName[0] == '\1')
212    return (void*)Dyld.getSymbolLoadAddress(BaseName.substr(1));
213  return (void*)Dyld.getSymbolLoadAddress((TM->getMCAsmInfo()->getGlobalPrefix()
214                                       + BaseName).str());
215}
216
217void *MCJIT::recompileAndRelinkFunction(Function *F) {
218  report_fatal_error("not yet implemented");
219}
220
221void MCJIT::freeMachineCodeForFunction(Function *F) {
222  report_fatal_error("not yet implemented");
223}
224
225GenericValue MCJIT::runFunction(Function *F,
226                                const std::vector<GenericValue> &ArgValues) {
227  assert(F && "Function *F was null at entry to run()");
228
229  void *FPtr = getPointerToFunction(F);
230  assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
231  FunctionType *FTy = F->getFunctionType();
232  Type *RetTy = FTy->getReturnType();
233
234  assert((FTy->getNumParams() == ArgValues.size() ||
235          (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
236         "Wrong number of arguments passed into function!");
237  assert(FTy->getNumParams() == ArgValues.size() &&
238         "This doesn't support passing arguments through varargs (yet)!");
239
240  // Handle some common cases first.  These cases correspond to common `main'
241  // prototypes.
242  if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
243    switch (ArgValues.size()) {
244    case 3:
245      if (FTy->getParamType(0)->isIntegerTy(32) &&
246          FTy->getParamType(1)->isPointerTy() &&
247          FTy->getParamType(2)->isPointerTy()) {
248        int (*PF)(int, char **, const char **) =
249          (int(*)(int, char **, const char **))(intptr_t)FPtr;
250
251        // Call the function.
252        GenericValue rv;
253        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
254                                 (char **)GVTOP(ArgValues[1]),
255                                 (const char **)GVTOP(ArgValues[2])));
256        return rv;
257      }
258      break;
259    case 2:
260      if (FTy->getParamType(0)->isIntegerTy(32) &&
261          FTy->getParamType(1)->isPointerTy()) {
262        int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
263
264        // Call the function.
265        GenericValue rv;
266        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
267                                 (char **)GVTOP(ArgValues[1])));
268        return rv;
269      }
270      break;
271    case 1:
272      if (FTy->getNumParams() == 1 &&
273          FTy->getParamType(0)->isIntegerTy(32)) {
274        GenericValue rv;
275        int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
276        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
277        return rv;
278      }
279      break;
280    }
281  }
282
283  // Handle cases where no arguments are passed first.
284  if (ArgValues.empty()) {
285    GenericValue rv;
286    switch (RetTy->getTypeID()) {
287    default: llvm_unreachable("Unknown return type for function call!");
288    case Type::IntegerTyID: {
289      unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
290      if (BitWidth == 1)
291        rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
292      else if (BitWidth <= 8)
293        rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
294      else if (BitWidth <= 16)
295        rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
296      else if (BitWidth <= 32)
297        rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
298      else if (BitWidth <= 64)
299        rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
300      else
301        llvm_unreachable("Integer types > 64 bits not supported");
302      return rv;
303    }
304    case Type::VoidTyID:
305      rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
306      return rv;
307    case Type::FloatTyID:
308      rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
309      return rv;
310    case Type::DoubleTyID:
311      rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
312      return rv;
313    case Type::X86_FP80TyID:
314    case Type::FP128TyID:
315    case Type::PPC_FP128TyID:
316      llvm_unreachable("long double not supported yet");
317    case Type::PointerTyID:
318      return PTOGV(((void*(*)())(intptr_t)FPtr)());
319    }
320  }
321
322  llvm_unreachable("Full-featured argument passing not supported yet!");
323}
324
325void *MCJIT::getPointerToNamedFunction(const std::string &Name,
326                                       bool AbortOnFailure) {
327  // FIXME: Add support for per-module compilation state
328  if (!IsLoaded)
329    loadObject(M);
330
331  if (!isSymbolSearchingDisabled() && MemMgr) {
332    void *ptr = MemMgr->getPointerToNamedFunction(Name, false);
333    if (ptr)
334      return ptr;
335  }
336
337  /// If a LazyFunctionCreator is installed, use it to get/create the function.
338  if (LazyFunctionCreator)
339    if (void *RP = LazyFunctionCreator(Name))
340      return RP;
341
342  if (AbortOnFailure) {
343    report_fatal_error("Program used external function '"+Name+
344                       "' which could not be resolved!");
345  }
346  return 0;
347}
348
349void MCJIT::RegisterJITEventListener(JITEventListener *L) {
350  if (L == NULL)
351    return;
352  MutexGuard locked(lock);
353  EventListeners.push_back(L);
354}
355void MCJIT::UnregisterJITEventListener(JITEventListener *L) {
356  if (L == NULL)
357    return;
358  MutexGuard locked(lock);
359  SmallVector<JITEventListener*, 2>::reverse_iterator I=
360      std::find(EventListeners.rbegin(), EventListeners.rend(), L);
361  if (I != EventListeners.rend()) {
362    std::swap(*I, EventListeners.back());
363    EventListeners.pop_back();
364  }
365}
366void MCJIT::NotifyObjectEmitted(const ObjectImage& Obj) {
367  MutexGuard locked(lock);
368  for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
369    EventListeners[I]->NotifyObjectEmitted(Obj);
370  }
371}
372void MCJIT::NotifyFreeingObject(const ObjectImage& Obj) {
373  MutexGuard locked(lock);
374  for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
375    EventListeners[I]->NotifyFreeingObject(Obj);
376  }
377}
378