llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldCOFF.cpp

   1 //===-- RuntimeDyldCOFF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-==//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Implementation of COFF support for the MC-JIT runtime dynamic linker.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "RuntimeDyldCOFF.h"
  14 #include "Targets/RuntimeDyldCOFFAArch64.h"
  15 #include "Targets/RuntimeDyldCOFFI386.h"
  16 #include "Targets/RuntimeDyldCOFFThumb.h"
  17 #include "Targets/RuntimeDyldCOFFX86_64.h"
  18 #include "llvm/Object/ObjectFile.h"
  19 #include "llvm/Support/FormatVariadic.h"
  20 #include "llvm/TargetParser/Triple.h"
  21
  22 using namespace llvm;
  23 using namespace llvm::object;
  24
  25 #define DEBUG_TYPE "dyld"
  26
  27 namespace {
  28
  29 class LoadedCOFFObjectInfo final
  30     : public LoadedObjectInfoHelper<LoadedCOFFObjectInfo,
  31                                     RuntimeDyld::LoadedObjectInfo> {
  32 public:
  33   LoadedCOFFObjectInfo(
  34       RuntimeDyldImpl &RTDyld,
  35       RuntimeDyld::LoadedObjectInfo::ObjSectionToIDMap ObjSecToIDMap)
  36       : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
  37
  38   OwningBinary<ObjectFile>
  39   getObjectForDebug(const ObjectFile &Obj) const override {
  40     return OwningBinary<ObjectFile>();
  41   }
  42 };
  43 }
  44
  45 namespace llvm {
  46
  47 std::unique_ptr<RuntimeDyldCOFF>
  48 llvm::RuntimeDyldCOFF::create(Triple::ArchType Arch,
  49                               RuntimeDyld::MemoryManager &MemMgr,
  50                               JITSymbolResolver &Resolver) {
  51   switch (Arch) {
  52   default: llvm_unreachable("Unsupported target for RuntimeDyldCOFF.");
  53   case Triple::x86:
  54     return std::make_unique<RuntimeDyldCOFFI386>(MemMgr, Resolver);
  55   case Triple::thumb:
  56     return std::make_unique<RuntimeDyldCOFFThumb>(MemMgr, Resolver);
  57   case Triple::x86_64:
  58     return std::make_unique<RuntimeDyldCOFFX86_64>(MemMgr, Resolver);
  59   case Triple::aarch64:
  60     return std::make_unique<RuntimeDyldCOFFAArch64>(MemMgr, Resolver);
  61   }
  62 }
  63
  64 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
  65 RuntimeDyldCOFF::loadObject(const object::ObjectFile &O) {
  66   if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) {
  67     return std::make_unique<LoadedCOFFObjectInfo>(*this, *ObjSectionToIDOrErr);
  68   } else {
  69     HasError = true;
  70     raw_string_ostream ErrStream(ErrorStr);
  71     logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream);
  72     return nullptr;
  73   }
  74 }
  75
  76 uint64_t RuntimeDyldCOFF::getSymbolOffset(const SymbolRef &Sym) {
  77   // The value in a relocatable COFF object is the offset.
  78   return cantFail(Sym.getValue());
  79 }
  80
  81 uint64_t RuntimeDyldCOFF::getDLLImportOffset(unsigned SectionID, StubMap &Stubs,
  82                                              StringRef Name,
  83                                              bool SetSectionIDMinus1) {
  84   LLVM_DEBUG(dbgs() << "Getting DLLImport entry for " << Name << "... ");
  85   assert(Name.starts_with(getImportSymbolPrefix()) &&
  86          "Not a DLLImport symbol?");
  87   RelocationValueRef Reloc;
  88   Reloc.SymbolName = Name.data();
  89   auto I = Stubs.find(Reloc);
  90   if (I != Stubs.end()) {
  91     LLVM_DEBUG(dbgs() << format("{0:x8}", I->second) << "\n");
  92     return I->second;
  93   }
  94
  95   assert(SectionID < Sections.size() && "SectionID out of range");
  96   auto &Sec = Sections[SectionID];
  97   auto EntryOffset = alignTo(Sec.getStubOffset(), PointerSize);
  98   Sec.advanceStubOffset(EntryOffset + PointerSize - Sec.getStubOffset());
  99   Stubs[Reloc] = EntryOffset;
 100
 101   RelocationEntry RE(SectionID, EntryOffset, PointerReloc, 0, false,
 102                      Log2_64(PointerSize));
 103   // Hack to tell I386/Thumb resolveRelocation that this isn't section relative.
 104   if (SetSectionIDMinus1)
 105     RE.Sections.SectionA = -1;
 106   addRelocationForSymbol(RE, Name.drop_front(getImportSymbolPrefix().size()));
 107
 108   LLVM_DEBUG({
 109     dbgs() << "Creating entry at "
 110            << formatv("{0:x16} + {1:x8} ( {2:x16} )", Sec.getLoadAddress(),
 111                       EntryOffset, Sec.getLoadAddress() + EntryOffset)
 112            << "\n";
 113   });
 114   return EntryOffset;
 115 }
 116
 117 bool RuntimeDyldCOFF::isCompatibleFile(const object::ObjectFile &Obj) const {
 118   return Obj.isCOFF();
 119 }
 120
 121 bool RuntimeDyldCOFF::relocationNeedsDLLImportStub(
 122     const RelocationRef &R) const {
 123   object::symbol_iterator Symbol = R.getSymbol();
 124   Expected<StringRef> TargetNameOrErr = Symbol->getName();
 125   if (!TargetNameOrErr)
 126     return false;
 127
 128   return TargetNameOrErr->starts_with(getImportSymbolPrefix());
 129 }
 130
 131 } // namespace llvm