MCJIT.cpp revision 3574eca1b02600bac4e625297f4ecf745f4c4f32 
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 "MCJITMemoryManager.h"
12#include "llvm/DerivedTypes.h"
13#include "llvm/Function.h"
14#include "llvm/ExecutionEngine/GenericValue.h"
15#include "llvm/ExecutionEngine/JITMemoryManager.h"
16#include "llvm/ExecutionEngine/MCJIT.h"
17#include "llvm/ExecutionEngine/ObjectBuffer.h"
18#include "llvm/ExecutionEngine/ObjectImage.h"
19#include "llvm/MC/MCAsmInfo.h"
20#include "llvm/Support/ErrorHandling.h"
21#include "llvm/Support/DynamicLibrary.h"
22#include "llvm/Support/MemoryBuffer.h"
23#include "llvm/Support/MutexGuard.h"
24#include "llvm/DataLayout.h"
25
26using namespace llvm;
27
28namespace {
29
30static struct RegisterJIT {
31  RegisterJIT() { MCJIT::Register(); }
32} JITRegistrator;
33
34}
35
36extern "C" void LLVMLinkInMCJIT() {
37}
38
39ExecutionEngine *MCJIT::createJIT(Module *M,
40                                  std::string *ErrorStr,
41                                  JITMemoryManager *JMM,
42                                  bool GVsWithCode,
43                                  TargetMachine *TM) {
44  // Try to register the program as a source of symbols to resolve against.
45  //
46  // FIXME: Don't do this here.
47  sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
48
49  return new MCJIT(M, TM, new MCJITMemoryManager(JMM), GVsWithCode);
50}
51
52MCJIT::MCJIT(Module *m, TargetMachine *tm, RTDyldMemoryManager *MM,
53             bool AllocateGVsWithCode)
54  : ExecutionEngine(m), TM(tm), Ctx(0), MemMgr(MM), Dyld(MM),
55    isCompiled(false), M(m)  {
56
57  setDataLayout(TM->getDataLayout());
58}
59
60MCJIT::~MCJIT() {
61  delete MemMgr;
62  delete TM;
63}
64
65void MCJIT::emitObject(Module *m) {
66  /// Currently, MCJIT only supports a single module and the module passed to
67  /// this function call is expected to be the contained module.  The module
68  /// is passed as a parameter here to prepare for multiple module support in
69  /// the future.
70  assert(M == m);
71
72  // Get a thread lock to make sure we aren't trying to compile multiple times
73  MutexGuard locked(lock);
74
75  // FIXME: Track compilation state on a per-module basis when multiple modules
76  //        are supported.
77  // Re-compilation is not supported
78  if (isCompiled)
79    return;
80
81  PassManager PM;
82
83  PM.add(new DataLayout(*TM->getDataLayout()));
84
85  // The RuntimeDyld will take ownership of this shortly
86  OwningPtr<ObjectBufferStream> Buffer(new ObjectBufferStream());
87
88  // Turn the machine code intermediate representation into bytes in memory
89  // that may be executed.
90  if (TM->addPassesToEmitMC(PM, Ctx, Buffer->getOStream(), false)) {
91    report_fatal_error("Target does not support MC emission!");
92  }
93
94  // Initialize passes.
95  PM.run(*m);
96  // Flush the output buffer to get the generated code into memory
97  Buffer->flush();
98
99  // Load the object into the dynamic linker.
100  // handing off ownership of the buffer
101  LoadedObject.reset(Dyld.loadObject(Buffer.take()));
102  if (!LoadedObject)
103    report_fatal_error(Dyld.getErrorString());
104
105  // Resolve any relocations.
106  Dyld.resolveRelocations();
107
108  // FIXME: Make this optional, maybe even move it to a JIT event listener
109  LoadedObject->registerWithDebugger();
110
111  // FIXME: Add support for per-module compilation state
112  isCompiled = true;
113}
114
115void *MCJIT::getPointerToBasicBlock(BasicBlock *BB) {
116  report_fatal_error("not yet implemented");
117}
118
119void *MCJIT::getPointerToFunction(Function *F) {
120  // FIXME: This should really return a uint64_t since it's a pointer in the
121  // target address space, not our local address space. That's part of the
122  // ExecutionEngine interface, though. Fix that when the old JIT finally
123  // dies.
124
125  // FIXME: Add support for per-module compilation state
126  if (!isCompiled)
127    emitObject(M);
128
129  if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
130    bool AbortOnFailure = !F->hasExternalWeakLinkage();
131    void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
132    addGlobalMapping(F, Addr);
133    return Addr;
134  }
135
136  // FIXME: Should the Dyld be retaining module information? Probably not.
137  // FIXME: Should we be using the mangler for this? Probably.
138  //
139  // This is the accessor for the target address, so make sure to check the
140  // load address of the symbol, not the local address.
141  StringRef BaseName = F->getName();
142  if (BaseName[0] == '\1')
143    return (void*)Dyld.getSymbolLoadAddress(BaseName.substr(1));
144  return (void*)Dyld.getSymbolLoadAddress((TM->getMCAsmInfo()->getGlobalPrefix()
145                                       + BaseName).str());
146}
147
148void *MCJIT::recompileAndRelinkFunction(Function *F) {
149  report_fatal_error("not yet implemented");
150}
151
152void MCJIT::freeMachineCodeForFunction(Function *F) {
153  report_fatal_error("not yet implemented");
154}
155
156GenericValue MCJIT::runFunction(Function *F,
157                                const std::vector<GenericValue> &ArgValues) {
158  assert(F && "Function *F was null at entry to run()");
159
160  void *FPtr = getPointerToFunction(F);
161  assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
162  FunctionType *FTy = F->getFunctionType();
163  Type *RetTy = FTy->getReturnType();
164
165  assert((FTy->getNumParams() == ArgValues.size() ||
166          (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
167         "Wrong number of arguments passed into function!");
168  assert(FTy->getNumParams() == ArgValues.size() &&
169         "This doesn't support passing arguments through varargs (yet)!");
170
171  // Handle some common cases first.  These cases correspond to common `main'
172  // prototypes.
173  if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
174    switch (ArgValues.size()) {
175    case 3:
176      if (FTy->getParamType(0)->isIntegerTy(32) &&
177          FTy->getParamType(1)->isPointerTy() &&
178          FTy->getParamType(2)->isPointerTy()) {
179        int (*PF)(int, char **, const char **) =
180          (int(*)(int, char **, const char **))(intptr_t)FPtr;
181
182        // Call the function.
183        GenericValue rv;
184        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
185                                 (char **)GVTOP(ArgValues[1]),
186                                 (const char **)GVTOP(ArgValues[2])));
187        return rv;
188      }
189      break;
190    case 2:
191      if (FTy->getParamType(0)->isIntegerTy(32) &&
192          FTy->getParamType(1)->isPointerTy()) {
193        int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
194
195        // Call the function.
196        GenericValue rv;
197        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
198                                 (char **)GVTOP(ArgValues[1])));
199        return rv;
200      }
201      break;
202    case 1:
203      if (FTy->getNumParams() == 1 &&
204          FTy->getParamType(0)->isIntegerTy(32)) {
205        GenericValue rv;
206        int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
207        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
208        return rv;
209      }
210      break;
211    }
212  }
213
214  // Handle cases where no arguments are passed first.
215  if (ArgValues.empty()) {
216    GenericValue rv;
217    switch (RetTy->getTypeID()) {
218    default: llvm_unreachable("Unknown return type for function call!");
219    case Type::IntegerTyID: {
220      unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
221      if (BitWidth == 1)
222        rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
223      else if (BitWidth <= 8)
224        rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
225      else if (BitWidth <= 16)
226        rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
227      else if (BitWidth <= 32)
228        rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
229      else if (BitWidth <= 64)
230        rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
231      else
232        llvm_unreachable("Integer types > 64 bits not supported");
233      return rv;
234    }
235    case Type::VoidTyID:
236      rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
237      return rv;
238    case Type::FloatTyID:
239      rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
240      return rv;
241    case Type::DoubleTyID:
242      rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
243      return rv;
244    case Type::X86_FP80TyID:
245    case Type::FP128TyID:
246    case Type::PPC_FP128TyID:
247      llvm_unreachable("long double not supported yet");
248    case Type::PointerTyID:
249      return PTOGV(((void*(*)())(intptr_t)FPtr)());
250    }
251  }
252
253  llvm_unreachable("Full-featured argument passing not supported yet!");
254}
255
256void *MCJIT::getPointerToNamedFunction(const std::string &Name,
257                                       bool AbortOnFailure) {
258  // FIXME: Add support for per-module compilation state
259  if (!isCompiled)
260    emitObject(M);
261
262  if (!isSymbolSearchingDisabled() && MemMgr) {
263    void *ptr = MemMgr->getPointerToNamedFunction(Name, false);
264    if (ptr)
265      return ptr;
266  }
267
268  /// If a LazyFunctionCreator is installed, use it to get/create the function.
269  if (LazyFunctionCreator)
270    if (void *RP = LazyFunctionCreator(Name))
271      return RP;
272
273  if (AbortOnFailure) {
274    report_fatal_error("Program used external function '"+Name+
275                       "' which could not be resolved!");
276  }
277  return 0;
278}
279