1 //===- Archive.cpp - ar File Format implementation --------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the ArchiveObjectFile class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Object/Archive.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/Support/MemoryBuffer.h"
19 using namespace object;
22 const StringRef Magic = "!<arch>\n";
24 struct ArchiveMemberHeader {
26 char LastModified[12];
30 char Size[10]; //< Size of data, not including header or padding.
33 ///! Get the name without looking up long names.
34 StringRef getName() const {
35 char EndCond = Name[0] == '/' ? ' ' : '/';
36 StringRef::size_type end = StringRef(Name, sizeof(Name)).find(EndCond);
37 if (end == StringRef::npos)
39 assert(end <= sizeof(Name) && end > 0);
40 // Don't include the EndCond if there is one.
41 return StringRef(Name, end);
44 uint64_t getSize() const {
46 StringRef(Size, sizeof(Size)).getAsInteger(10, ret);
47 return ret.getZExtValue();
51 const ArchiveMemberHeader *ToHeader(const char *base) {
52 return reinterpret_cast<const ArchiveMemberHeader *>(base);
56 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.
63 const char *NextLoc = Data.data() + SpaceToSkip;
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));
69 size_t NextSize = sizeof(ArchiveMemberHeader) +
70 ToHeader(NextLoc)->getSize();
72 return Child(Parent, StringRef(NextLoc, NextSize));
75 error_code Archive::Child::getName(StringRef &Result) const {
76 StringRef name = ToHeader(Data.data())->getName();
77 // Check if it's a special name.
79 if (name.size() == 1) { // Linker member.
81 return object_error::success;
83 if (name.size() == 2 && name[1] == '/') { // String table.
85 return object_error::success;
90 name.substr(1).getAsInteger(10, offset);
91 const char *addr = Parent->StringTable->Data.begin()
92 + sizeof(ArchiveMemberHeader)
93 + offset.getZExtValue();
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;
103 return object_error::success;
105 // It's a simple name.
106 if (name[name.size() - 1] == '/')
107 Result = name.substr(0, name.size() - 1);
110 return object_error::success;
113 uint64_t Archive::Child::getSize() const {
114 return ToHeader(Data.data())->getSize();
117 MemoryBuffer *Archive::Child::getBuffer() const {
119 if (getName(name)) return NULL;
120 return MemoryBuffer::getMemBuffer(Data.substr(sizeof(ArchiveMemberHeader),
126 error_code Archive::Child::getAsBinary(OwningPtr<Binary> &Result) const {
127 OwningPtr<Binary> ret;
129 createBinary(getBuffer(), ret))
132 return object_error::success;
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;
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);
151 // Check to see if there were 3 members, or the 3rd member wasn't named "//".
153 if (StrTable != e && !StrTable->getName(name) && name == "//")
154 StringTable = StrTable;
156 ec = object_error::success;
159 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));
166 Archive::child_iterator Archive::end_children() const {
167 return Child(this, StringRef(0, 0));
172 } // end namespace llvm