lib/ExecutionEngine/MCJIT/MCJIT.cpp

   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
  23 using namespace llvm;
  24
  25 namespace {
  26
  27 static struct RegisterJIT {
  28   RegisterJIT() { MCJIT::Register(); }
  29 } JITRegistrator;
  30
  31 }
  32
  33 extern "C" void LLVMLinkInMCJIT() {
  34 }
  35
  36 ExecutionEngine *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
  57 MCJIT::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   PM.add(new TargetData(*TM->getTargetData()));
  63
  64   // Turn the machine code intermediate representation into bytes in memory
  65   // that may be executed.
  66   if (TM->addPassesToEmitMC(PM, Ctx, OS, CodeGenOpt::Default, false)) {
  67     report_fatal_error("Target does not support MC emission!");
  68   }
  69
  70   // Initialize passes.
  71   // FIXME: When we support multiple modules, we'll want to move the code
  72   // gen and finalization out of the constructor here and do it more
  73   // on-demand as part of getPointerToFunction().
  74   PM.run(*M);
  75   // Flush the output buffer so the SmallVector gets its data.
  76   OS.flush();
  77
  78   // Load the object into the dynamic linker.
  79   // FIXME: It would be nice to avoid making yet another copy.
  80   MemoryBuffer *MB = MemoryBuffer::getMemBufferCopy(StringRef(Buffer.data(),
  81                                                               Buffer.size()));
  82   if (Dyld.loadObject(MB))
  83     report_fatal_error(Dyld.getErrorString());
  84   // Resolve any relocations.
  85   Dyld.resolveRelocations();
  86 }
  87
  88 MCJIT::~MCJIT() {
  89   delete MemMgr;
  90 }
  91
  92 void *MCJIT::getPointerToBasicBlock(BasicBlock *BB) {
  93   report_fatal_error("not yet implemented");
  94   return 0;
  95 }
  96
  97 void *MCJIT::getPointerToFunction(Function *F) {
  98   if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
  99     bool AbortOnFailure = !F->hasExternalWeakLinkage();
 100     void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
 101     addGlobalMapping(F, Addr);
 102     return Addr;
 103   }
 104
 105   // FIXME: Should we be using the mangler for this? Probably.
 106   StringRef BaseName = F->getName();
 107   if (BaseName[0] == '\1')
 108     return (void*)Dyld.getSymbolAddress(BaseName.substr(1));
 109   return (void*)Dyld.getSymbolAddress((TM->getMCAsmInfo()->getGlobalPrefix()
 110                                        + BaseName).str());
 111 }
 112
 113 void *MCJIT::recompileAndRelinkFunction(Function *F) {
 114   report_fatal_error("not yet implemented");
 115 }
 116
 117 void MCJIT::freeMachineCodeForFunction(Function *F) {
 118   report_fatal_error("not yet implemented");
 119 }
 120
 121 GenericValue MCJIT::runFunction(Function *F,
 122                                 const std::vector<GenericValue> &ArgValues) {
 123   assert(F && "Function *F was null at entry to run()");
 124
 125   void *FPtr = getPointerToFunction(F);
 126   assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
 127   const FunctionType *FTy = F->getFunctionType();
 128   const Type *RetTy = FTy->getReturnType();
 129
 130   assert((FTy->getNumParams() == ArgValues.size() ||
 131           (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
 132          "Wrong number of arguments passed into function!");
 133   assert(FTy->getNumParams() == ArgValues.size() &&
 134          "This doesn't support passing arguments through varargs (yet)!");
 135
 136   // Handle some common cases first.  These cases correspond to common `main'
 137   // prototypes.
 138   if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
 139     switch (ArgValues.size()) {
 140     case 3:
 141       if (FTy->getParamType(0)->isIntegerTy(32) &&
 142           FTy->getParamType(1)->isPointerTy() &&
 143           FTy->getParamType(2)->isPointerTy()) {
 144         int (*PF)(int, char **, const char **) =
 145           (int(*)(int, char **, const char **))(intptr_t)FPtr;
 146
 147         // Call the function.
 148         GenericValue rv;
 149         rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
 150                                  (char **)GVTOP(ArgValues[1]),
 151                                  (const char **)GVTOP(ArgValues[2])));
 152         return rv;
 153       }
 154       break;
 155     case 2:
 156       if (FTy->getParamType(0)->isIntegerTy(32) &&
 157           FTy->getParamType(1)->isPointerTy()) {
 158         int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
 159
 160         // Call the function.
 161         GenericValue rv;
 162         rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
 163                                  (char **)GVTOP(ArgValues[1])));
 164         return rv;
 165       }
 166       break;
 167     case 1:
 168       if (FTy->getNumParams() == 1 &&
 169           FTy->getParamType(0)->isIntegerTy(32)) {
 170         GenericValue rv;
 171         int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
 172         rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
 173         return rv;
 174       }
 175       break;
 176     }
 177   }
 178
 179   // Handle cases where no arguments are passed first.
 180   if (ArgValues.empty()) {
 181     GenericValue rv;
 182     switch (RetTy->getTypeID()) {
 183     default: llvm_unreachable("Unknown return type for function call!");
 184     case Type::IntegerTyID: {
 185       unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
 186       if (BitWidth == 1)
 187         rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
 188       else if (BitWidth <= 8)
 189         rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
 190       else if (BitWidth <= 16)
 191         rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
 192       else if (BitWidth <= 32)
 193         rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
 194       else if (BitWidth <= 64)
 195         rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
 196       else
 197         llvm_unreachable("Integer types > 64 bits not supported");
 198       return rv;
 199     }
 200     case Type::VoidTyID:
 201       rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
 202       return rv;
 203     case Type::FloatTyID:
 204       rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
 205       return rv;
 206     case Type::DoubleTyID:
 207       rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
 208       return rv;
 209     case Type::X86_FP80TyID:
 210     case Type::FP128TyID:
 211     case Type::PPC_FP128TyID:
 212       llvm_unreachable("long double not supported yet");
 213       return rv;
 214     case Type::PointerTyID:
 215       return PTOGV(((void*(*)())(intptr_t)FPtr)());
 216     }
 217   }
 218
 219   assert("Full-featured argument passing not supported yet!");
 220   return GenericValue();
 221 }