lib/ExecutionEngine/JITLink/MachO.cpp

   1 //===-------------- MachO.cpp - JIT linker function for MachO -------------===//
   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 // MachO jit-link function.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ExecutionEngine/JITLink/MachO.h"
  15
  16 #include "llvm/BinaryFormat/MachO.h"
  17 #include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h"
  18 #include "llvm/Support/Endian.h"
  19 #include "llvm/Support/Format.h"
  20 #include "llvm/Support/MemoryBuffer.h"
  21
  22 using namespace llvm;
  23
  24 #define DEBUG_TYPE "jitlink"
  25
  26 namespace llvm {
  27 namespace jitlink {
  28
  29 void jitLink_MachO(std::unique_ptr<JITLinkContext> Ctx) {
  30
  31   // We don't want to do full MachO validation here. Just parse enough of the
  32   // header to find out what MachO linker to use.
  33
  34   StringRef Data = Ctx->getObjectBuffer().getBuffer();
  35   if (Data.size() < 4) {
  36     Ctx->notifyFailed(make_error<JITLinkError>("Truncated MachO buffer"));
  37     return;
  38   }
  39
  40   uint32_t Magic;
  41   memcpy(&Magic, Data.data(), sizeof(uint32_t));
  42   LLVM_DEBUG({
  43     dbgs() << "jitLink_MachO: magic = " << format("0x%08" PRIx32, Magic)
  44            << ", identifier = \""
  45            << Ctx->getObjectBuffer().getBufferIdentifier() << "\"\n";
  46   });
  47
  48   if (Magic == MachO::MH_MAGIC || Magic == MachO::MH_CIGAM) {
  49     Ctx->notifyFailed(
  50         make_error<JITLinkError>("MachO 32-bit platforms not supported"));
  51     return;
  52   } else if (Magic == MachO::MH_MAGIC_64 || Magic == MachO::MH_CIGAM_64) {
  53     MachO::mach_header_64 Header;
  54
  55     memcpy(&Header, Data.data(), sizeof(MachO::mach_header_64));
  56     if (Magic == MachO::MH_CIGAM_64)
  57       swapStruct(Header);
  58
  59     LLVM_DEBUG({
  60       dbgs() << "jitLink_MachO: cputype = "
  61              << format("0x%08" PRIx32, Header.cputype)
  62              << ", cpusubtype = " << format("0x%08" PRIx32, Header.cpusubtype)
  63              << "\n";
  64     });
  65
  66     switch (Header.cputype) {
  67     case MachO::CPU_TYPE_X86_64:
  68       return jitLink_MachO_x86_64(std::move(Ctx));
  69     }
  70     Ctx->notifyFailed(make_error<JITLinkError>("MachO-64 CPU type not valid"));
  71     return;
  72   }
  73
  74   Ctx->notifyFailed(make_error<JITLinkError>("MachO magic not valid"));
  75 }
  76
  77 } // end namespace jitlink
  78 } // end namespace llvm