1//===- Archive.h - ar archive file format -----------------------*- C++ -*-===//
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// This file declares the ar archive file format class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_OBJECT_ARCHIVE_H
14#define LLVM_OBJECT_ARCHIVE_H
15
16#include "llvm/ADT/Optional.h"
17#include "llvm/ADT/StringRef.h"
18#include "llvm/ADT/fallible_iterator.h"
19#include "llvm/ADT/iterator_range.h"
20#include "llvm/Object/Binary.h"
21#include "llvm/Support/Chrono.h"
22#include "llvm/Support/Error.h"
23#include "llvm/Support/FileSystem.h"
24#include "llvm/Support/MemoryBuffer.h"
25#include <algorithm>
26#include <cassert>
27#include <cstdint>
28#include <memory>
29#include <string>
30#include <vector>
31
32namespace llvm {
33namespace object {
34
35class Archive;
36
37class ArchiveMemberHeader {
38public:
39 friend class Archive;
40
41 ArchiveMemberHeader(Archive const *Parent, const char *RawHeaderPtr,
42 uint64_t Size, Error *Err);
43 // ArchiveMemberHeader() = default;
44
45 /// Get the name without looking up long names.
46 Expected<StringRef> getRawName() const;
47
48 /// Get the name looking up long names.
49 Expected<StringRef> getName(uint64_t Size) const;
50
51 Expected<uint64_t> getSize() const;
52
53 Expected<sys::fs::perms> getAccessMode() const;
54 Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const;
55
56 StringRef getRawLastModified() const {
57 return StringRef(ArMemHdr->LastModified,
58 sizeof(ArMemHdr->LastModified)).rtrim(' ');
59 }
60
61 Expected<unsigned> getUID() const;
62 Expected<unsigned> getGID() const;
63
64 // This returns the size of the private struct ArMemHdrType
65 uint64_t getSizeOf() const {
66 return sizeof(ArMemHdrType);
67 }
68
69private:
70 struct ArMemHdrType {
71 char Name[16];
72 char LastModified[12];
73 char UID[6];
74 char GID[6];
75 char AccessMode[8];
76 char Size[10]; ///< Size of data, not including header or padding.
77 char Terminator[2];
78 };
79 Archive const *Parent;
80 ArMemHdrType const *ArMemHdr;
81};
82
83class Archive : public Binary {
84 virtual void anchor();
85
86public:
87 class Child {
88 friend Archive;
89 friend ArchiveMemberHeader;
90
91 const Archive *Parent;
92 ArchiveMemberHeader Header;
93 /// Includes header but not padding byte.
94 StringRef Data;
95 /// Offset from Data to the start of the file.
96 uint16_t StartOfFile;
97
98 Expected<bool> isThinMember() const;
99
100 public:
101 Child(const Archive *Parent, const char *Start, Error *Err);
102 Child(const Archive *Parent, StringRef Data, uint16_t StartOfFile);
103
104 bool operator ==(const Child &other) const {
105 assert(!Parent || !other.Parent || Parent == other.Parent);
106 return Data.begin() == other.Data.begin();
107 }
108
109 const Archive *getParent() const { return Parent; }
110 Expected<Child> getNext() const;
111
112 Expected<StringRef> getName() const;
113 Expected<std::string> getFullName() const;
114 Expected<StringRef> getRawName() const { return Header.getRawName(); }
115
116 Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const {
117 return Header.getLastModified();
118 }
119
120 StringRef getRawLastModified() const {
121 return Header.getRawLastModified();
122 }
123
124 Expected<unsigned> getUID() const { return Header.getUID(); }
125 Expected<unsigned> getGID() const { return Header.getGID(); }
126
127 Expected<sys::fs::perms> getAccessMode() const {
128 return Header.getAccessMode();
129 }
130
131 /// \return the size of the archive member without the header or padding.
132 Expected<uint64_t> getSize() const;
133 /// \return the size in the archive header for this member.
134 Expected<uint64_t> getRawSize() const;
135
136 Expected<StringRef> getBuffer() const;
137 uint64_t getChildOffset() const;
138 uint64_t getDataOffset() const { return getChildOffset() + StartOfFile; }
139
140 Expected<MemoryBufferRef> getMemoryBufferRef() const;
141
142 Expected<std::unique_ptr<Binary>>
143 getAsBinary(LLVMContext *Context = nullptr) const;
144 };
145
146 class ChildFallibleIterator {
147 Child C;
148
149 public:
150 ChildFallibleIterator() : C(Child(nullptr, nullptr, nullptr)) {}
151 ChildFallibleIterator(const Child &C) : C(C) {}
152
153 const Child *operator->() const { return &C; }
154 const Child &operator*() const { return C; }
155
156 bool operator==(const ChildFallibleIterator &other) const {
157 // Ignore errors here: If an error occurred during increment then getNext
158 // will have been set to child_end(), and the following comparison should
159 // do the right thing.
160 return C == other.C;
161 }
162
163 bool operator!=(const ChildFallibleIterator &other) const {
164 return !(*this == other);
165 }
166
167 Error inc() {
168 auto NextChild = C.getNext();
169 if (!NextChild)
170 return NextChild.takeError();
171 C = std::move(*NextChild);
172 return Error::success();
173 }
174 };
175
176 using child_iterator = fallible_iterator<ChildFallibleIterator>;
177
178 class Symbol {
179 const Archive *Parent;
180 uint32_t SymbolIndex;
181 uint32_t StringIndex; // Extra index to the string.
182
183 public:
184 Symbol(const Archive *p, uint32_t symi, uint32_t stri)
185 : Parent(p)
186 , SymbolIndex(symi)
187 , StringIndex(stri) {}
188
189 bool operator ==(const Symbol &other) const {
190 return (Parent == other.Parent) && (SymbolIndex == other.SymbolIndex);
191 }
192
193 StringRef getName() const;
194 Expected<Child> getMember() const;
195 Symbol getNext() const;
196 };
197
198 class symbol_iterator {
199 Symbol symbol;
200
201 public:
202 symbol_iterator(const Symbol &s) : symbol(s) {}
203
204 const Symbol *operator->() const { return &symbol; }
205 const Symbol &operator*() const { return symbol; }
206
207 bool operator==(const symbol_iterator &other) const {
208 return symbol == other.symbol;
209 }
210
211 bool operator!=(const symbol_iterator &other) const {
212 return !(*this == other);
213 }
214
215 symbol_iterator& operator++() { // Preincrement
216 symbol = symbol.getNext();
217 return *this;
218 }
219 };
220
221 Archive(MemoryBufferRef Source, Error &Err);
222 static Expected<std::unique_ptr<Archive>> create(MemoryBufferRef Source);
223
224 /// Size field is 10 decimal digits long
225 static const uint64_t MaxMemberSize = 9999999999;
226
227 enum Kind {
228 K_GNU,
229 K_GNU64,
230 K_BSD,
231 K_DARWIN,
232 K_DARWIN64,
233 K_COFF
234 };
235
236 Kind kind() const { return (Kind)Format; }
237 bool isThin() const { return IsThin; }
238
239 child_iterator child_begin(Error &Err, bool SkipInternal = true) const;
240 child_iterator child_end() const;
241 iterator_range<child_iterator> children(Error &Err,
242 bool SkipInternal = true) const {
243 return make_range(child_begin(Err, SkipInternal), child_end());
244 }
245
246 symbol_iterator symbol_begin() const;
247 symbol_iterator symbol_end() const;
248 iterator_range<symbol_iterator> symbols() const {
249 return make_range(symbol_begin(), symbol_end());
250 }
251
252 // Cast methods.
253 static bool classof(Binary const *v) {
254 return v->isArchive();
255 }
256
257 // check if a symbol is in the archive
258 Expected<Optional<Child>> findSym(StringRef name) const;
259
260 bool isEmpty() const;
261 bool hasSymbolTable() const;
262 StringRef getSymbolTable() const { return SymbolTable; }
263 StringRef getStringTable() const { return StringTable; }
264 uint32_t getNumberOfSymbols() const;
265
266 std::vector<std::unique_ptr<MemoryBuffer>> takeThinBuffers() {
267 return std::move(ThinBuffers);
268 }
269
270private:
271 StringRef SymbolTable;
272 StringRef StringTable;
273
274 StringRef FirstRegularData;
275 uint16_t FirstRegularStartOfFile = -1;
276 void setFirstRegular(const Child &C);
277
278 unsigned Format : 3;
279 unsigned IsThin : 1;
280 mutable std::vector<std::unique_ptr<MemoryBuffer>> ThinBuffers;
281};
282
283} // end namespace object
284} // end namespace llvm
285
286#endif // LLVM_OBJECT_ARCHIVE_H
287