File: | build/source/llvm/lib/ExecutionEngine/JITLink/COFF.cpp |
Warning: | line 98, column 7 Value stored to 'CurPtr' is never read |
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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 "llvm/Support/Endian.h" |
19 | #include "llvm/Support/Format.h" |
20 | #include "llvm/Support/MemoryBuffer.h" |
21 | #include <cstring> |
22 | |
23 | using namespace llvm; |
24 | |
25 | #define DEBUG_TYPE"jitlink" "jitlink" |
26 | |
27 | namespace llvm { |
28 | namespace jitlink { |
29 | |
30 | static StringRef getMachineName(uint16_t Machine) { |
31 | switch (Machine) { |
32 | case COFF::IMAGE_FILE_MACHINE_I386: |
33 | return "i386"; |
34 | case COFF::IMAGE_FILE_MACHINE_AMD64: |
35 | return "x86_64"; |
36 | case COFF::IMAGE_FILE_MACHINE_ARMNT: |
37 | return "ARM"; |
38 | case COFF::IMAGE_FILE_MACHINE_ARM64: |
39 | return "ARM64"; |
40 | default: |
41 | return "unknown"; |
42 | } |
43 | } |
44 | |
45 | Expected<std::unique_ptr<LinkGraph>> |
46 | createLinkGraphFromCOFFObject(MemoryBufferRef ObjectBuffer) { |
47 | StringRef Data = ObjectBuffer.getBuffer(); |
48 | |
49 | // Check magic |
50 | auto Magic = identify_magic(ObjectBuffer.getBuffer()); |
51 | if (Magic != file_magic::coff_object) |
52 | return make_error<JITLinkError>("Invalid COFF buffer"); |
53 | |
54 | if (Data.size() < sizeof(object::coff_file_header)) |
55 | return make_error<JITLinkError>("Truncated COFF buffer"); |
56 | |
57 | uint64_t CurPtr = 0; |
58 | bool IsPE = false; |
59 | |
60 | // Check if this is a PE/COFF file. |
61 | if (Data.size() >= sizeof(object::dos_header) + sizeof(COFF::PEMagic)) { |
62 | const auto *DH = |
63 | reinterpret_cast<const object::dos_header *>(Data.data() + CurPtr); |
64 | if (DH->Magic[0] == 'M' && DH->Magic[1] == 'Z') { |
65 | // Check the PE magic bytes. ("PE\0\0") |
66 | CurPtr = DH->AddressOfNewExeHeader; |
67 | if (memcmp(Data.data() + CurPtr, COFF::PEMagic, sizeof(COFF::PEMagic)) != |
68 | 0) { |
69 | return make_error<JITLinkError>("Incorrect PE magic"); |
70 | } |
71 | CurPtr += sizeof(COFF::PEMagic); |
72 | IsPE = true; |
73 | } |
74 | } |
75 | if (Data.size() < CurPtr + sizeof(object::coff_file_header)) |
76 | return make_error<JITLinkError>("Truncated COFF buffer"); |
77 | |
78 | const object::coff_file_header *COFFHeader = |
79 | reinterpret_cast<const object::coff_file_header *>(Data.data() + CurPtr); |
80 | const object::coff_bigobj_file_header *COFFBigObjHeader = nullptr; |
81 | |
82 | // Deal with bigobj file |
83 | if (!IsPE && COFFHeader->Machine == COFF::IMAGE_FILE_MACHINE_UNKNOWN && |
84 | COFFHeader->NumberOfSections == uint16_t(0xffff) && |
85 | Data.size() >= sizeof(object::coff_bigobj_file_header)) { |
86 | if (Data.size() < sizeof(object::coff_file_header)) { |
87 | return make_error<JITLinkError>("Truncated COFF buffer"); |
88 | } |
89 | COFFBigObjHeader = |
90 | reinterpret_cast<const object::coff_bigobj_file_header *>(Data.data() + |
91 | CurPtr); |
92 | |
93 | // Verify that we are dealing with bigobj. |
94 | if (COFFBigObjHeader->Version >= COFF::BigObjHeader::MinBigObjectVersion && |
95 | std::memcmp(COFFBigObjHeader->UUID, COFF::BigObjMagic, |
96 | sizeof(COFF::BigObjMagic)) == 0) { |
97 | COFFHeader = nullptr; |
98 | CurPtr += sizeof(object::coff_bigobj_file_header); |
Value stored to 'CurPtr' is never read | |
99 | } else |
100 | COFFBigObjHeader = nullptr; |
101 | } |
102 | |
103 | uint16_t Machine = |
104 | COFFHeader ? COFFHeader->Machine : COFFBigObjHeader->Machine; |
105 | LLVM_DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("jitlink")) { { dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no") << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no") << ", identifier = \"" << ObjectBuffer .getBufferIdentifier() << "\" " << "machine = " << getMachineName(Machine) << "\n"; }; } } while (false) |
106 | dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("jitlink")) { { dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no") << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no") << ", identifier = \"" << ObjectBuffer .getBufferIdentifier() << "\" " << "machine = " << getMachineName(Machine) << "\n"; }; } } while (false) |
107 | << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("jitlink")) { { dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no") << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no") << ", identifier = \"" << ObjectBuffer .getBufferIdentifier() << "\" " << "machine = " << getMachineName(Machine) << "\n"; }; } } while (false) |
108 | << ", identifier = \"" << ObjectBuffer.getBufferIdentifier() << "\" "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("jitlink")) { { dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no") << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no") << ", identifier = \"" << ObjectBuffer .getBufferIdentifier() << "\" " << "machine = " << getMachineName(Machine) << "\n"; }; } } while (false) |
109 | << "machine = " << getMachineName(Machine) << "\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("jitlink")) { { dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no") << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no") << ", identifier = \"" << ObjectBuffer .getBufferIdentifier() << "\" " << "machine = " << getMachineName(Machine) << "\n"; }; } } while (false) |
110 | })do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("jitlink")) { { dbgs() << "jitLink_COFF: PE = " << (IsPE ? "yes" : "no") << ", bigobj = " << (COFFBigObjHeader ? "yes" : "no") << ", identifier = \"" << ObjectBuffer .getBufferIdentifier() << "\" " << "machine = " << getMachineName(Machine) << "\n"; }; } } while (false); |
111 | |
112 | switch (Machine) { |
113 | case COFF::IMAGE_FILE_MACHINE_AMD64: |
114 | return createLinkGraphFromCOFFObject_x86_64(ObjectBuffer); |
115 | default: |
116 | return make_error<JITLinkError>( |
117 | "Unsupported target machine architecture in COFF object " + |
118 | ObjectBuffer.getBufferIdentifier() + ": " + getMachineName(Machine)); |
119 | } |
120 | } |
121 | |
122 | void link_COFF(std::unique_ptr<LinkGraph> G, |
123 | std::unique_ptr<JITLinkContext> Ctx) { |
124 | switch (G->getTargetTriple().getArch()) { |
125 | case Triple::x86_64: |
126 | link_COFF_x86_64(std::move(G), std::move(Ctx)); |
127 | return; |
128 | default: |
129 | Ctx->notifyFailed(make_error<JITLinkError>( |
130 | "Unsupported target machine architecture in COFF link graph " + |
131 | G->getName())); |
132 | return; |
133 | } |
134 | } |
135 | |
136 | } // end namespace jitlink |
137 | } // end namespace llvm |