xref: /llvm-project/llvm/lib/ExecutionEngine/JITLink/COFF.cpp (revision 2ccf7ed277df28651b94bbee9fccefdf22fb074f)
1 //===-------------- COFF.cpp - JIT linker function for COFF -------------===//
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 // COFF jit-link function.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ExecutionEngine/JITLink/COFF.h"
14 
15 #include "llvm/BinaryFormat/COFF.h"
16 #include "llvm/ExecutionEngine/JITLink/COFF_x86_64.h"
17 #include "llvm/Object/COFF.h"
18 #include <cstring>
19 
20 using namespace llvm;
21 
22 #define DEBUG_TYPE "jitlink"
23 
24 namespace llvm {
25 namespace jitlink {
26 
27 static StringRef getMachineName(uint16_t Machine) {
28   switch (Machine) {
29   case COFF::IMAGE_FILE_MACHINE_I386:
30     return "i386";
31   case COFF::IMAGE_FILE_MACHINE_AMD64:
32     return "x86_64";
33   case COFF::IMAGE_FILE_MACHINE_ARMNT:
34     return "ARM";
35   case COFF::IMAGE_FILE_MACHINE_ARM64:
36     return "ARM64";
37   default:
38     return "unknown";
39   }
40 }
41 
42 Expected<std::unique_ptr<LinkGraph>>
43 createLinkGraphFromCOFFObject(MemoryBufferRef ObjectBuffer,
44                               std::shared_ptr<orc::SymbolStringPool> SSP) {
45   StringRef Data = ObjectBuffer.getBuffer();
46 
47   // Check magic
48   auto Magic = identify_magic(ObjectBuffer.getBuffer());
49   if (Magic != file_magic::coff_object)
50     return make_error<JITLinkError>("Invalid COFF buffer");
51 
52   if (Data.size() < sizeof(object::coff_file_header))
53     return make_error<JITLinkError>("Truncated COFF buffer");
54 
55   uint64_t CurPtr = 0;
56   bool IsPE = false;
57 
58   // Check if this is a PE/COFF file.
59   if (Data.size() >= sizeof(object::dos_header) + sizeof(COFF::PEMagic)) {
60     const auto *DH =
61         reinterpret_cast<const object::dos_header *>(Data.data() + CurPtr);
62     if (DH->Magic[0] == 'M' && DH->Magic[1] == 'Z') {
63       // Check the PE magic bytes. ("PE\0\0")
64       CurPtr = DH->AddressOfNewExeHeader;
65       if (memcmp(Data.data() + CurPtr, COFF::PEMagic, sizeof(COFF::PEMagic)) !=
66           0) {
67         return make_error<JITLinkError>("Incorrect PE magic");
68       }
69       CurPtr += sizeof(COFF::PEMagic);
70       IsPE = true;
71     }
72   }
73   if (Data.size() < CurPtr + sizeof(object::coff_file_header))
74     return make_error<JITLinkError>("Truncated COFF buffer");
75 
76   const object::coff_file_header *COFFHeader =
77       reinterpret_cast<const object::coff_file_header *>(Data.data() + CurPtr);
78   const object::coff_bigobj_file_header *COFFBigObjHeader = nullptr;
79 
80   // Deal with bigobj file
81   if (!IsPE && COFFHeader->Machine == COFF::IMAGE_FILE_MACHINE_UNKNOWN &&
82       COFFHeader->NumberOfSections == uint16_t(0xffff) &&
83       Data.size() >= sizeof(object::coff_bigobj_file_header)) {
84     if (Data.size() < sizeof(object::coff_file_header)) {
85       return make_error<JITLinkError>("Truncated COFF buffer");
86     }
87     COFFBigObjHeader =
88         reinterpret_cast<const object::coff_bigobj_file_header *>(Data.data() +
89                                                                   CurPtr);
90 
91     // Verify that we are dealing with bigobj.
92     if (COFFBigObjHeader->Version >= COFF::BigObjHeader::MinBigObjectVersion &&
93         std::memcmp(COFFBigObjHeader->UUID, COFF::BigObjMagic,
94                     sizeof(COFF::BigObjMagic)) == 0) {
95       COFFHeader = nullptr;
96       CurPtr += sizeof(object::coff_bigobj_file_header);
97     } else
98       COFFBigObjHeader = nullptr;
99   }
100 
101   uint16_t Machine =
102       COFFHeader ? COFFHeader->Machine : COFFBigObjHeader->Machine;
103   LLVM_DEBUG({
104     dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no")
105            << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no")
106            << ", identifier = \"" << ObjectBuffer.getBufferIdentifier() << "\" "
107            << "machine = " << getMachineName(Machine) << "\n";
108   });
109 
110   switch (Machine) {
111   case COFF::IMAGE_FILE_MACHINE_AMD64:
112     return createLinkGraphFromCOFFObject_x86_64(ObjectBuffer, std::move(SSP));
113   default:
114     return make_error<JITLinkError>(
115         "Unsupported target machine architecture in COFF object " +
116         ObjectBuffer.getBufferIdentifier() + ": " + getMachineName(Machine));
117   }
118 }
119 
120 void link_COFF(std::unique_ptr<LinkGraph> G,
121                std::unique_ptr<JITLinkContext> Ctx) {
122   switch (G->getTargetTriple().getArch()) {
123   case Triple::x86_64:
124     link_COFF_x86_64(std::move(G), std::move(Ctx));
125     return;
126   default:
127     Ctx->notifyFailed(make_error<JITLinkError>(
128         "Unsupported target machine architecture in COFF link graph " +
129         G->getName()));
130     return;
131   }
132 }
133 
134 } // end namespace jitlink
135 } // end namespace llvm
136