1 //===- Archive.cpp - ar File Format implementation --------------*- C++ -*-===//
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 // This file defines the ArchiveObjectFile class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/Object/Archive.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/Support/MemoryBuffer.h"
17
18 using namespace llvm;
19 using namespace object;
20
21 namespace {
22 const StringRef Magic = "!<arch>\n";
23
24 struct ArchiveMemberHeader {
25 char Name[16];
26 char LastModified[12];
27 char UID[6];
28 char GID[6];
29 char AccessMode[8];
30 char Size[10]; //< Size of data, not including header or padding.
31 char Terminator[2];
32
33 ///! Get the name without looking up long names.
getName__anond85b87e50111::ArchiveMemberHeader34 StringRef getName() const {
35 char EndCond = Name[0] == '/' ? ' ' : '/';
36 StringRef::size_type end = StringRef(Name, sizeof(Name)).find(EndCond);
37 if (end == StringRef::npos)
38 end = sizeof(Name);
39 assert(end <= sizeof(Name) && end > 0);
40 // Don't include the EndCond if there is one.
41 return StringRef(Name, end);
42 }
43
getSize__anond85b87e50111::ArchiveMemberHeader44 uint64_t getSize() const {
45 APInt ret;
46 StringRef(Size, sizeof(Size)).getAsInteger(10, ret);
47 return ret.getZExtValue();
48 }
49 };
50
ToHeader(const char * base)51 const ArchiveMemberHeader *ToHeader(const char *base) {
52 return reinterpret_cast<const ArchiveMemberHeader *>(base);
53 }
54 }
55
getNext() const56 Archive::Child Archive::Child::getNext() const {
57 size_t SpaceToSkip = sizeof(ArchiveMemberHeader) +
58 ToHeader(Data.data())->getSize();
59 // If it's odd, add 1 to make it even.
60 if (SpaceToSkip & 1)
61 ++SpaceToSkip;
62
63 const char *NextLoc = Data.data() + SpaceToSkip;
64
65 // Check to see if this is past the end of the archive.
66 if (NextLoc >= Parent->Data->getBufferEnd())
67 return Child(Parent, StringRef(0, 0));
68
69 size_t NextSize = sizeof(ArchiveMemberHeader) +
70 ToHeader(NextLoc)->getSize();
71
72 return Child(Parent, StringRef(NextLoc, NextSize));
73 }
74
getName(StringRef & Result) const75 error_code Archive::Child::getName(StringRef &Result) const {
76 StringRef name = ToHeader(Data.data())->getName();
77 // Check if it's a special name.
78 if (name[0] == '/') {
79 if (name.size() == 1) { // Linker member.
80 Result = name;
81 return object_error::success;
82 }
83 if (name.size() == 2 && name[1] == '/') { // String table.
84 Result = name;
85 return object_error::success;
86 }
87 // It's a long name.
88 // Get the offset.
89 APInt offset;
90 name.substr(1).getAsInteger(10, offset);
91 const char *addr = Parent->StringTable->Data.begin()
92 + sizeof(ArchiveMemberHeader)
93 + offset.getZExtValue();
94 // Verify it.
95 if (Parent->StringTable == Parent->end_children()
96 || addr < (Parent->StringTable->Data.begin()
97 + sizeof(ArchiveMemberHeader))
98 || addr > (Parent->StringTable->Data.begin()
99 + sizeof(ArchiveMemberHeader)
100 + Parent->StringTable->getSize()))
101 return object_error::parse_failed;
102 Result = addr;
103 return object_error::success;
104 }
105 // It's a simple name.
106 if (name[name.size() - 1] == '/')
107 Result = name.substr(0, name.size() - 1);
108 else
109 Result = name;
110 return object_error::success;
111 }
112
getSize() const113 uint64_t Archive::Child::getSize() const {
114 return ToHeader(Data.data())->getSize();
115 }
116
getBuffer() const117 MemoryBuffer *Archive::Child::getBuffer() const {
118 StringRef name;
119 if (getName(name)) return NULL;
120 return MemoryBuffer::getMemBuffer(Data.substr(sizeof(ArchiveMemberHeader),
121 getSize()),
122 name,
123 false);
124 }
125
getAsBinary(OwningPtr<Binary> & Result) const126 error_code Archive::Child::getAsBinary(OwningPtr<Binary> &Result) const {
127 OwningPtr<Binary> ret;
128 if (error_code ec =
129 createBinary(getBuffer(), ret))
130 return ec;
131 Result.swap(ret);
132 return object_error::success;
133 }
134
Archive(MemoryBuffer * source,error_code & ec)135 Archive::Archive(MemoryBuffer *source, error_code &ec)
136 : Binary(Binary::isArchive, source)
137 , StringTable(Child(this, StringRef(0, 0))) {
138 // Check for sufficient magic.
139 if (!source || source->getBufferSize()
140 < (8 + sizeof(ArchiveMemberHeader) + 2) // Smallest archive.
141 || StringRef(source->getBufferStart(), 8) != Magic) {
142 ec = object_error::invalid_file_type;
143 return;
144 }
145
146 // Get the string table. It's the 3rd member.
147 child_iterator StrTable = begin_children();
148 child_iterator e = end_children();
149 for (int i = 0; StrTable != e && i < 2; ++StrTable, ++i) {}
150
151 // Check to see if there were 3 members, or the 3rd member wasn't named "//".
152 StringRef name;
153 if (StrTable != e && !StrTable->getName(name) && name == "//")
154 StringTable = StrTable;
155
156 ec = object_error::success;
157 }
158
begin_children() const159 Archive::child_iterator Archive::begin_children() const {
160 const char *Loc = Data->getBufferStart() + Magic.size();
161 size_t Size = sizeof(ArchiveMemberHeader) +
162 ToHeader(Loc)->getSize();
163 return Child(this, StringRef(Loc, Size));
164 }
165
end_children() const166 Archive::child_iterator Archive::end_children() const {
167 return Child(this, StringRef(0, 0));
168 }
169
170 namespace llvm {
171
172 } // end namespace llvm
173