lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

   1 //===-- RuntimeDyld.cpp - Run-time dynamic linker for MC-JIT ----*- C++ -*-===//
   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 // Implementation of the MC-JIT runtime dynamic linker.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #define DEBUG_TYPE "dyld"
  15 #include "RuntimeDyldImpl.h"
  16 #include "llvm/Support/Path.h"
  17 using namespace llvm;
  18 using namespace llvm::object;
  19
  20 // Empty out-of-line virtual destructor as the key function.
  21 RTDyldMemoryManager::~RTDyldMemoryManager() {}
  22 RuntimeDyldImpl::~RuntimeDyldImpl() {}
  23
  24 namespace llvm {
  25
  26 void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress,
  27                                       uint8_t *EndAddress) {
  28   // FIXME: DEPRECATED in favor of by-section allocation.
  29   // Allocate memory for the function via the memory manager.
  30   uintptr_t Size = EndAddress - StartAddress + 1;
  31   uintptr_t AllocSize = Size;
  32   uint8_t *Mem = MemMgr->startFunctionBody(Name.data(), AllocSize);
  33   assert(Size >= (uint64_t)(EndAddress - StartAddress + 1) &&
  34          "Memory manager failed to allocate enough memory!");
  35   // Copy the function payload into the memory block.
  36   memcpy(Mem, StartAddress, Size);
  37   MemMgr->endFunctionBody(Name.data(), Mem, Mem + Size);
  38   // Remember where we put it.
  39   unsigned SectionID = Sections.size();
  40   Sections.push_back(sys::MemoryBlock(Mem, Size));
  41
  42   // Default the assigned address for this symbol to wherever this
  43   // allocated it.
  44   SymbolTable[Name] = SymbolLoc(SectionID, 0);
  45   DEBUG(dbgs() << "    allocated to [" << Mem << ", " << Mem + Size << "]\n");
  46 }
  47
  48 // Resolve the relocations for all symbols we currently know about.
  49 void RuntimeDyldImpl::resolveRelocations() {
  50   // Just iterate over the sections we have and resolve all the relocations
  51   // in them. Gross overkill, but it gets the job done.
  52   for (int i = 0, e = Sections.size(); i != e; ++i) {
  53     reassignSectionAddress(i, SectionLoadAddress[i]);
  54   }
  55 }
  56
  57 void RuntimeDyldImpl::mapSectionAddress(void *LocalAddress,
  58                                         uint64_t TargetAddress) {
  59   assert(SectionLocalMemToID.count(LocalAddress) &&
  60          "Attempting to remap address of unknown section!");
  61   unsigned SectionID = SectionLocalMemToID[LocalAddress];
  62   reassignSectionAddress(SectionID, TargetAddress);
  63 }
  64
  65 //===----------------------------------------------------------------------===//
  66 // RuntimeDyld class implementation
  67 RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) {
  68   Dyld = 0;
  69   MM = mm;
  70 }
  71
  72 RuntimeDyld::~RuntimeDyld() {
  73   delete Dyld;
  74 }
  75
  76 bool RuntimeDyld::loadObject(MemoryBuffer *InputBuffer) {
  77   if (!Dyld) {
  78     sys::LLVMFileType type = sys::IdentifyFileType(
  79             InputBuffer->getBufferStart(),
  80             static_cast<unsigned>(InputBuffer->getBufferSize()));
  81     switch (type) {
  82       case sys::ELF_Relocatable_FileType:
  83       case sys::ELF_Executable_FileType:
  84       case sys::ELF_SharedObject_FileType:
  85       case sys::ELF_Core_FileType:
  86         Dyld = new RuntimeDyldELF(MM);
  87         break;
  88       case sys::Mach_O_Object_FileType:
  89       case sys::Mach_O_Executable_FileType:
  90       case sys::Mach_O_FixedVirtualMemorySharedLib_FileType:
  91       case sys::Mach_O_Core_FileType:
  92       case sys::Mach_O_PreloadExecutable_FileType:
  93       case sys::Mach_O_DynamicallyLinkedSharedLib_FileType:
  94       case sys::Mach_O_DynamicLinker_FileType:
  95       case sys::Mach_O_Bundle_FileType:
  96       case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType:
  97       case sys::Mach_O_DSYMCompanion_FileType:
  98         Dyld = new RuntimeDyldMachO(MM);
  99         break;
 100       case sys::Unknown_FileType:
 101       case sys::Bitcode_FileType:
 102       case sys::Archive_FileType:
 103       case sys::COFF_FileType:
 104         report_fatal_error("Incompatible object format!");
 105     }
 106   } else {
 107     if (!Dyld->isCompatibleFormat(InputBuffer))
 108       report_fatal_error("Incompatible object format!");
 109   }
 110
 111   return Dyld->loadObject(InputBuffer);
 112 }
 113
 114 void *RuntimeDyld::getSymbolAddress(StringRef Name) {
 115   return Dyld->getSymbolAddress(Name);
 116 }
 117
 118 void RuntimeDyld::resolveRelocations() {
 119   Dyld->resolveRelocations();
 120 }
 121
 122 void RuntimeDyld::reassignSectionAddress(unsigned SectionID,
 123                                          uint64_t Addr) {
 124   Dyld->reassignSectionAddress(SectionID, Addr);
 125 }
 126
 127 void RuntimeDyld::mapSectionAddress(void *LocalAddress,
 128                                     uint64_t TargetAddress) {
 129   Dyld->mapSectionAddress(LocalAddress, TargetAddress);
 130 }
 131
 132 StringRef RuntimeDyld::getErrorString() {
 133   return Dyld->getErrorString();
 134 }
 135
 136 } // end namespace llvm