MCJIT.cpp revision 7803ec3d458ec73372760b838469292cdf38fe67 
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/MCJIT.h"
16#include "llvm/ExecutionEngine/JITMemoryManager.h"
17#include "llvm/MC/MCAsmInfo.h"
18#include "llvm/Support/ErrorHandling.h"
19#include "llvm/Support/DynamicLibrary.h"
20#include "llvm/Support/MemoryBuffer.h"
21#include "llvm/Target/TargetData.h"
22
23using namespace llvm;
24
25namespace {
26
27static struct RegisterJIT {
28  RegisterJIT() { MCJIT::Register(); }
29} JITRegistrator;
30
31}
32
33extern "C" void LLVMLinkInMCJIT() {
34}
35
36ExecutionEngine *MCJIT::createJIT(Module *M,
37                                  std::string *ErrorStr,
38                                  JITMemoryManager *JMM,
39                                  bool GVsWithCode,
40                                  TargetMachine *TM) {
41  // Try to register the program as a source of symbols to resolve against.
42  //
43  // FIXME: Don't do this here.
44  sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
45
46  // If the target supports JIT code generation, create the JIT.
47  if (TargetJITInfo *TJ = TM->getJITInfo())
48    return new MCJIT(M, TM, *TJ, new MCJITMemoryManager(JMM, M), GVsWithCode);
49
50  if (ErrorStr)
51    *ErrorStr = "target does not support JIT code generation";
52  return 0;
53}
54
55MCJIT::MCJIT(Module *m, TargetMachine *tm, TargetJITInfo &tji,
56             RTDyldMemoryManager *MM, bool AllocateGVsWithCode)
57  : ExecutionEngine(m), TM(tm), MemMgr(MM), M(m), OS(Buffer), Dyld(MM) {
58
59  setTargetData(TM->getTargetData());
60  PM.add(new TargetData(*TM->getTargetData()));
61
62  // Turn the machine code intermediate representation into bytes in memory
63  // that may be executed.
64  if (TM->addPassesToEmitMC(PM, Ctx, OS, false)) {
65    report_fatal_error("Target does not support MC emission!");
66  }
67
68  // Initialize passes.
69  // FIXME: When we support multiple modules, we'll want to move the code
70  // gen and finalization out of the constructor here and do it more
71  // on-demand as part of getPointerToFunction().
72  PM.run(*M);
73  // Flush the output buffer so the SmallVector gets its data.
74  OS.flush();
75
76  // Load the object into the dynamic linker.
77  // FIXME: It would be nice to avoid making yet another copy.
78  MemoryBuffer *MB = MemoryBuffer::getMemBufferCopy(StringRef(Buffer.data(),
79                                                              Buffer.size()));
80  if (Dyld.loadObject(MB))
81    report_fatal_error(Dyld.getErrorString());
82  // Resolve any relocations.
83  Dyld.resolveRelocations();
84}
85
86MCJIT::~MCJIT() {
87  delete MemMgr;
88  delete TM;
89}
90
91void *MCJIT::getPointerToBasicBlock(BasicBlock *BB) {
92  report_fatal_error("not yet implemented");
93}
94
95void *MCJIT::getPointerToFunction(Function *F) {
96  if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
97    bool AbortOnFailure = !F->hasExternalWeakLinkage();
98    void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
99    addGlobalMapping(F, Addr);
100    return Addr;
101  }
102
103  // FIXME: Should we be using the mangler for this? Probably.
104  StringRef BaseName = F->getName();
105  if (BaseName[0] == '\1')
106    return (void*)Dyld.getSymbolAddress(BaseName.substr(1));
107  return (void*)Dyld.getSymbolAddress((TM->getMCAsmInfo()->getGlobalPrefix()
108                                       + BaseName).str());
109}
110
111void *MCJIT::recompileAndRelinkFunction(Function *F) {
112  report_fatal_error("not yet implemented");
113}
114
115void MCJIT::freeMachineCodeForFunction(Function *F) {
116  report_fatal_error("not yet implemented");
117}
118
119GenericValue MCJIT::runFunction(Function *F,
120                                const std::vector<GenericValue> &ArgValues) {
121  assert(F && "Function *F was null at entry to run()");
122
123  void *FPtr = getPointerToFunction(F);
124  assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
125  FunctionType *FTy = F->getFunctionType();
126  Type *RetTy = FTy->getReturnType();
127
128  assert((FTy->getNumParams() == ArgValues.size() ||
129          (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
130         "Wrong number of arguments passed into function!");
131  assert(FTy->getNumParams() == ArgValues.size() &&
132         "This doesn't support passing arguments through varargs (yet)!");
133
134  // Handle some common cases first.  These cases correspond to common `main'
135  // prototypes.
136  if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
137    switch (ArgValues.size()) {
138    case 3:
139      if (FTy->getParamType(0)->isIntegerTy(32) &&
140          FTy->getParamType(1)->isPointerTy() &&
141          FTy->getParamType(2)->isPointerTy()) {
142        int (*PF)(int, char **, const char **) =
143          (int(*)(int, char **, const char **))(intptr_t)FPtr;
144
145        // Call the function.
146        GenericValue rv;
147        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
148                                 (char **)GVTOP(ArgValues[1]),
149                                 (const char **)GVTOP(ArgValues[2])));
150        return rv;
151      }
152      break;
153    case 2:
154      if (FTy->getParamType(0)->isIntegerTy(32) &&
155          FTy->getParamType(1)->isPointerTy()) {
156        int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
157
158        // Call the function.
159        GenericValue rv;
160        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
161                                 (char **)GVTOP(ArgValues[1])));
162        return rv;
163      }
164      break;
165    case 1:
166      if (FTy->getNumParams() == 1 &&
167          FTy->getParamType(0)->isIntegerTy(32)) {
168        GenericValue rv;
169        int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
170        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
171        return rv;
172      }
173      break;
174    }
175  }
176
177  // Handle cases where no arguments are passed first.
178  if (ArgValues.empty()) {
179    GenericValue rv;
180    switch (RetTy->getTypeID()) {
181    default: llvm_unreachable("Unknown return type for function call!");
182    case Type::IntegerTyID: {
183      unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
184      if (BitWidth == 1)
185        rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
186      else if (BitWidth <= 8)
187        rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
188      else if (BitWidth <= 16)
189        rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
190      else if (BitWidth <= 32)
191        rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
192      else if (BitWidth <= 64)
193        rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
194      else
195        llvm_unreachable("Integer types > 64 bits not supported");
196      return rv;
197    }
198    case Type::VoidTyID:
199      rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
200      return rv;
201    case Type::FloatTyID:
202      rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
203      return rv;
204    case Type::DoubleTyID:
205      rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
206      return rv;
207    case Type::X86_FP80TyID:
208    case Type::FP128TyID:
209    case Type::PPC_FP128TyID:
210      llvm_unreachable("long double not supported yet");
211    case Type::PointerTyID:
212      return PTOGV(((void*(*)())(intptr_t)FPtr)());
213    }
214  }
215
216  llvm_unreachable("Full-featured argument passing not supported yet!");
217}
218
219void *MCJIT::getPointerToNamedFunction(const std::string &Name,
220                                       bool AbortOnFailure){
221  if (!isSymbolSearchingDisabled()) {
222    void *ptr = MemMgr->getPointerToNamedFunction(Name, false);
223    if (ptr)
224      return ptr;
225  }
226
227  /// If a LazyFunctionCreator is installed, use it to get/create the function.
228  if (LazyFunctionCreator)
229    if (void *RP = LazyFunctionCreator(Name))
230      return RP;
231
232  if (AbortOnFailure) {
233    report_fatal_error("Program used external function '"+Name+
234                      "' which could not be resolved!");
235  }
236  return 0;
237}
238