1 //===-------------- MachO.cpp - JIT linker function for MachO -------------===//
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 // MachO jit-link function.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ExecutionEngine/JITLink/MachO.h"
14 
15 #include "llvm/BinaryFormat/MachO.h"
16 #include "llvm/ExecutionEngine/JITLink/MachO_arm64.h"
17 #include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h"
18 #include "llvm/Support/Format.h"
19 #include "llvm/Support/MemoryBuffer.h"
20 #include "llvm/Support/SwapByteOrder.h"
21 
22 using namespace llvm;
23 
24 #define DEBUG_TYPE "jitlink"
25 
26 namespace llvm {
27 namespace jitlink {
28 
29 Expected<std::unique_ptr<LinkGraph>>
30 createLinkGraphFromMachOObject(MemoryBufferRef ObjectBuffer) {
31   StringRef Data = ObjectBuffer.getBuffer();
32   if (Data.size() < 4)
33     return make_error<JITLinkError>("Truncated MachO buffer \"" +
34                                     ObjectBuffer.getBufferIdentifier() + "\"");
35 
36   uint32_t Magic;
37   memcpy(&Magic, Data.data(), sizeof(uint32_t));
38   LLVM_DEBUG({
39     dbgs() << "jitLink_MachO: magic = " << format("0x%08" PRIx32, Magic)
40            << ", identifier = \"" << ObjectBuffer.getBufferIdentifier()
41            << "\"\n";
42   });
43 
44   if (Magic == MachO::MH_MAGIC || Magic == MachO::MH_CIGAM)
45     return make_error<JITLinkError>("MachO 32-bit platforms not supported");
46   else if (Magic == MachO::MH_MAGIC_64 || Magic == MachO::MH_CIGAM_64) {
47 
48     if (Data.size() < sizeof(MachO::mach_header_64))
49       return make_error<JITLinkError>("Truncated MachO buffer \"" +
50                                       ObjectBuffer.getBufferIdentifier() +
51                                       "\"");
52 
53     // Read the CPU type from the header.
54     uint32_t CPUType;
55     memcpy(&CPUType, Data.data() + 4, sizeof(uint32_t));
56     if (Magic == MachO::MH_CIGAM_64)
57       CPUType = llvm::byteswap<uint32_t>(CPUType);
58 
59     LLVM_DEBUG({
60       dbgs() << "jitLink_MachO: cputype = " << format("0x%08" PRIx32, CPUType)
61              << "\n";
62     });
63 
64     switch (CPUType) {
65     case MachO::CPU_TYPE_ARM64:
66       return createLinkGraphFromMachOObject_arm64(ObjectBuffer);
67     case MachO::CPU_TYPE_X86_64:
68       return createLinkGraphFromMachOObject_x86_64(ObjectBuffer);
69     }
70     return make_error<JITLinkError>("MachO-64 CPU type not valid");
71   } else
72     return make_error<JITLinkError>("Unrecognized MachO magic value");
73 }
74 
75 void link_MachO(std::unique_ptr<LinkGraph> G,
76                 std::unique_ptr<JITLinkContext> Ctx) {
77 
78   switch (G->getTargetTriple().getArch()) {
79   case Triple::aarch64:
80     return link_MachO_arm64(std::move(G), std::move(Ctx));
81   case Triple::x86_64:
82     return link_MachO_x86_64(std::move(G), std::move(Ctx));
83   default:
84     Ctx->notifyFailed(make_error<JITLinkError>("MachO-64 CPU type not valid"));
85     return;
86   }
87 }
88 
89 } // end namespace jitlink
90 } // end namespace llvm
91