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/Format.h"
20 #include "llvm/Support/MemoryBuffer.h"
21 #include "llvm/Support/SwapByteOrder.h"
22 
23 using namespace llvm;
24 
25 #define DEBUG_TYPE "jitlink"
26 
27 namespace llvm {
28 namespace jitlink {
29 
30 Expected<std::unique_ptr<LinkGraph>>
31 createLinkGraphFromMachOObject(MemoryBufferRef ObjectBuffer) {
32   StringRef Data = ObjectBuffer.getBuffer();
33   if (Data.size() < 4)
34     return make_error<JITLinkError>("Truncated MachO buffer \"" +
35                                     ObjectBuffer.getBufferIdentifier() + "\"");
36 
37   uint32_t Magic;
38   memcpy(&Magic, Data.data(), sizeof(uint32_t));
39   LLVM_DEBUG({
40     dbgs() << "jitLink_MachO: magic = " << format("0x%08" PRIx32, Magic)
41            << ", identifier = \"" << ObjectBuffer.getBufferIdentifier()
42            << "\"\n";
43   });
44 
45   if (Magic == MachO::MH_MAGIC || Magic == MachO::MH_CIGAM)
46     return make_error<JITLinkError>("MachO 32-bit platforms not supported");
47   else if (Magic == MachO::MH_MAGIC_64 || Magic == MachO::MH_CIGAM_64) {
48 
49     if (Data.size() < sizeof(MachO::mach_header_64))
50       return make_error<JITLinkError>("Truncated MachO buffer \"" +
51                                       ObjectBuffer.getBufferIdentifier() +
52                                       "\"");
53 
54     // Read the CPU type from the header.
55     uint32_t CPUType;
56     memcpy(&CPUType, Data.data() + 4, sizeof(uint32_t));
57     if (Magic == MachO::MH_CIGAM_64)
58       CPUType = ByteSwap_32(CPUType);
59 
60     LLVM_DEBUG({
61       dbgs() << "jitLink_MachO: cputype = " << format("0x%08" PRIx32, CPUType)
62              << "\n";
63     });
64 
65     switch (CPUType) {
66     case MachO::CPU_TYPE_ARM64:
67       return createLinkGraphFromMachOObject_arm64(std::move(ObjectBuffer));
68     case MachO::CPU_TYPE_X86_64:
69       return createLinkGraphFromMachOObject_x86_64(std::move(ObjectBuffer));
70     }
71     return make_error<JITLinkError>("MachO-64 CPU type not valid");
72   } else
73     return make_error<JITLinkError>("Unrecognized MachO magic value");
74 }
75 
76 void link_MachO(std::unique_ptr<LinkGraph> G,
77                 std::unique_ptr<JITLinkContext> Ctx) {
78 
79   switch (G->getTargetTriple().getArch()) {
80   case Triple::aarch64:
81     return link_MachO_arm64(std::move(G), std::move(Ctx));
82   case Triple::x86_64:
83     return link_MachO_x86_64(std::move(G), std::move(Ctx));
84   default:
85     Ctx->notifyFailed(make_error<JITLinkError>("MachO-64 CPU type not valid"));
86     return;
87   }
88 }
89 
90 } // end namespace jitlink
91 } // end namespace llvm
92