1 //===-------------- ELF.cpp - JIT linker function for ELF -------------===// 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 // ELF jit-link function. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/ExecutionEngine/JITLink/ELF.h" 15 16 #include "llvm/BinaryFormat/ELF.h" 17 #include "llvm/ExecutionEngine/JITLink/ELF_x86_64.h" 18 #include "llvm/Object/ELF.h" 19 #include "llvm/Support/Endian.h" 20 #include "llvm/Support/Format.h" 21 #include "llvm/Support/MemoryBuffer.h" 22 #include <cstring> 23 24 using namespace llvm; 25 26 #define DEBUG_TYPE "jitlink" 27 28 namespace llvm { 29 namespace jitlink { 30 31 Expected<uint16_t> readTargetMachineArch(StringRef Buffer) { 32 const char *Data = Buffer.data(); 33 34 if (Data[ELF::EI_DATA] == ELF::ELFDATA2LSB) { 35 if (Data[ELF::EI_CLASS] == ELF::ELFCLASS64) { 36 if (auto File = llvm::object::ELF64LEFile::create(Buffer)) { 37 return File->getHeader().e_machine; 38 } else { 39 return File.takeError(); 40 } 41 } else if (Data[ELF::EI_CLASS] == ELF::ELFCLASS32) { 42 if (auto File = llvm::object::ELF32LEFile::create(Buffer)) { 43 return File->getHeader().e_machine; 44 } else { 45 return File.takeError(); 46 } 47 } 48 } 49 50 return ELF::EM_NONE; 51 } 52 53 Expected<std::unique_ptr<LinkGraph>> 54 createLinkGraphFromELFObject(MemoryBufferRef ObjectBuffer) { 55 StringRef Buffer = ObjectBuffer.getBuffer(); 56 if (Buffer.size() < ELF::EI_MAG3 + 1) 57 return make_error<JITLinkError>("Truncated ELF buffer"); 58 59 if (memcmp(Buffer.data(), ELF::ElfMagic, strlen(ELF::ElfMagic)) != 0) 60 return make_error<JITLinkError>("ELF magic not valid"); 61 62 Expected<uint16_t> TargetMachineArch = readTargetMachineArch(Buffer); 63 if (!TargetMachineArch) 64 return TargetMachineArch.takeError(); 65 66 switch (*TargetMachineArch) { 67 case ELF::EM_X86_64: 68 return createLinkGraphFromELFObject_x86_64(std::move(ObjectBuffer)); 69 default: 70 return make_error<JITLinkError>( 71 "Unsupported target machine architecture in ELF object " + 72 ObjectBuffer.getBufferIdentifier()); 73 } 74 } 75 76 void link_ELF(std::unique_ptr<LinkGraph> G, 77 std::unique_ptr<JITLinkContext> Ctx) { 78 switch (G->getTargetTriple().getArch()) { 79 case Triple::x86_64: 80 link_ELF_x86_64(std::move(G), std::move(Ctx)); 81 return; 82 default: 83 Ctx->notifyFailed(make_error<JITLinkError>( 84 "Unsupported target machine architecture in ELF link graph " + 85 G->getName())); 86 return; 87 } 88 } 89 90 } // end namespace jitlink 91 } // end namespace llvm 92