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