MachO.cpp revision 360784 
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_arm64.h"
18#include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h"
19#include "llvm/Support/Endian.h"
20#include "llvm/Support/Format.h"
21#include "llvm/Support/MemoryBuffer.h"
22
23using namespace llvm;
24
25#define DEBUG_TYPE "jitlink"
26
27namespace llvm {
28namespace jitlink {
29
30void jitLink_MachO(std::unique_ptr<JITLinkContext> Ctx) {
31
32  // We don't want to do full MachO validation here. Just parse enough of the
33  // header to find out what MachO linker to use.
34
35  StringRef Data = Ctx->getObjectBuffer().getBuffer();
36  if (Data.size() < 4) {
37    Ctx->notifyFailed(make_error<JITLinkError>("Truncated MachO buffer"));
38    return;
39  }
40
41  uint32_t Magic;
42  memcpy(&Magic, Data.data(), sizeof(uint32_t));
43  LLVM_DEBUG({
44    dbgs() << "jitLink_MachO: magic = " << format("0x%08" PRIx32, Magic)
45           << ", identifier = \""
46           << Ctx->getObjectBuffer().getBufferIdentifier() << "\"\n";
47  });
48
49  if (Magic == MachO::MH_MAGIC || Magic == MachO::MH_CIGAM) {
50    Ctx->notifyFailed(
51        make_error<JITLinkError>("MachO 32-bit platforms not supported"));
52    return;
53  } else if (Magic == MachO::MH_MAGIC_64 || Magic == MachO::MH_CIGAM_64) {
54    MachO::mach_header_64 Header;
55
56    memcpy(&Header, Data.data(), sizeof(MachO::mach_header_64));
57    if (Magic == MachO::MH_CIGAM_64)
58      swapStruct(Header);
59
60    LLVM_DEBUG({
61      dbgs() << "jitLink_MachO: cputype = "
62             << format("0x%08" PRIx32, Header.cputype)
63             << ", cpusubtype = " << format("0x%08" PRIx32, Header.cpusubtype)
64             << "\n";
65    });
66
67    switch (Header.cputype) {
68    case MachO::CPU_TYPE_ARM64:
69      return jitLink_MachO_arm64(std::move(Ctx));
70    case MachO::CPU_TYPE_X86_64:
71      return jitLink_MachO_x86_64(std::move(Ctx));
72    }
73    Ctx->notifyFailed(make_error<JITLinkError>("MachO-64 CPU type not valid"));
74    return;
75  }
76
77  Ctx->notifyFailed(make_error<JITLinkError>("MachO magic not valid"));
78}
79
80} // end namespace jitlink
81} // end namespace llvm
82