1 //===-- llvm/Bitcode/Archive.h - LLVM Bitcode Archive -----------*- 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 header file declares the Archive and ArchiveMember classes that provide
11 // manipulation of LLVM Archive files. The implementation is provided by the
12 // lib/Bitcode/Archive library. This library is used to read and write
13 // archive (*.a) files that contain LLVM bitcode files (or others).
15 //===----------------------------------------------------------------------===//
17 #ifndef TOOLS_LLVM_AR_ARCHIVE_H
18 #define TOOLS_LLVM_AR_ARCHIVE_H
20 #include "llvm/ADT/ilist.h"
21 #include "llvm/ADT/ilist_node.h"
22 #include "llvm/Support/Path.h"
23 #include "llvm/Support/raw_ostream.h"
24 #include "llvm/Support/TimeValue.h"
32 // Forward declare classes
33 class Module; // From VMCore
34 class Archive; // Declared below
35 class ArchiveMemberHeader; // Internal implementation class
36 class LLVMContext; // Global data
38 /// This class is the main class manipulated by users of the Archive class. It
39 /// holds information about one member of the Archive. It is also the element
40 /// stored by the Archive's ilist, the Archive's main abstraction. Because of
41 /// the special requirements of archive files, users are not permitted to
42 /// construct ArchiveMember instances. You should obtain them from the methods
43 /// of the Archive class instead.
44 /// @brief This class represents a single archive member.
45 class ArchiveMember : public ilist_node<ArchiveMember> {
49 /// These flags are used internally by the archive member to specify various
50 /// characteristics of the member. The various "is" methods below provide
51 /// access to the flags. The flags are not user settable.
53 SVR4SymbolTableFlag = 1, ///< Member is a SVR4 symbol table
54 BSD4SymbolTableFlag = 2, ///< Member is a BSD4 symbol table
55 HasLongFilenameFlag = 8, ///< Member uses the long filename syntax
56 StringTableFlag = 16 ///< Member is an ar(1) format string table
63 /// @returns the parent Archive instance
64 /// @brief Get the archive associated with this member
65 Archive* getArchive() const { return parent; }
67 /// @returns the path to the Archive's file
68 /// @brief Get the path to the archive member
69 StringRef getPath() const { return path; }
71 /// The "user" is the owner of the file per Unix security. This may not
72 /// have any applicability on non-Unix systems but is a required component
73 /// of the "ar" file format.
74 /// @brief Get the user associated with this archive member.
75 unsigned getUser() const { return User; }
77 /// The "group" is the owning group of the file per Unix security. This
78 /// may not have any applicability on non-Unix systems but is a required
79 /// component of the "ar" file format.
80 /// @brief Get the group associated with this archive member.
81 unsigned getGroup() const { return Group; }
83 /// The "mode" specifies the access permissions for the file per Unix
84 /// security. This may not have any applicability on non-Unix systems but is
85 /// a required component of the "ar" file format.
86 /// @brief Get the permission mode associated with this archive member.
87 unsigned getMode() const { return Mode; }
89 /// This method returns the time at which the archive member was last
90 /// modified when it was not in the archive.
91 /// @brief Get the time of last modification of the archive member.
92 sys::TimeValue getModTime() const { return ModTime; }
94 /// @returns the size of the archive member in bytes.
95 /// @brief Get the size of the archive member.
96 uint64_t getSize() const { return Size; }
98 /// This method returns the total size of the archive member as it
99 /// appears on disk. This includes the file content, the header, the
100 /// long file name if any, and the padding.
101 /// @brief Get total on-disk member size.
102 unsigned getMemberSize() const;
104 /// This method will return a pointer to the in-memory content of the
105 /// archive member, if it is available. If the data has not been loaded
106 /// into memory, the return value will be null.
107 /// @returns a pointer to the member's data.
108 /// @brief Get the data content of the archive member
109 const char* getData() const { return data; }
111 /// @returns true iff the member is a SVR4 (non-LLVM) symbol table
112 /// @brief Determine if this member is a SVR4 symbol table.
113 bool isSVR4SymbolTable() const { return flags&SVR4SymbolTableFlag; }
115 /// @returns true iff the member is a BSD4.4 (non-LLVM) symbol table
116 /// @brief Determine if this member is a BSD4.4 symbol table.
117 bool isBSD4SymbolTable() const { return flags&BSD4SymbolTableFlag; }
119 /// @returns true iff the archive member is the ar(1) string table
120 /// @brief Determine if this member is the ar(1) string table.
121 bool isStringTable() const { return flags&StringTableFlag; }
123 /// Long filenames are an artifact of the ar(1) file format which allows
124 /// up to sixteen characters in its header and doesn't allow a path
125 /// separator character (/). To avoid this, a "long format" member name is
126 /// allowed that doesn't have this restriction. This method determines if
127 /// that "long format" is used for this member.
128 /// @returns true iff the file name uses the long form
129 /// @brief Determine if the member has a long file name
130 bool hasLongFilename() const { return flags&HasLongFilenameFlag; }
132 /// This method causes the archive member to be replaced with the contents
133 /// of the file specified by \p File. The contents of \p this will be
134 /// updated to reflect the new data from \p File. The \p File must exist and
135 /// be readable on entry to this method.
136 /// @returns true if an error occurred, false otherwise
137 /// @brief Replace contents of archive member with a new file.
138 bool replaceWith(StringRef aFile, std::string* ErrMsg);
144 Archive *parent; ///< Pointer to parent archive
145 std::string path; ///< Path of file containing the member
149 sys::TimeValue ModTime;
151 unsigned flags; ///< Flags about the archive member
152 const char *data; ///< Data for the member
155 /// @name Constructors
158 /// The default constructor is only used by the Archive's iplist when it
159 /// constructs the list's sentry node.
163 /// Used internally by the Archive class to construct an ArchiveMember.
164 /// The contents of the ArchiveMember are filled out by the Archive class.
165 explicit ArchiveMember(Archive *PAR);
167 // So Archive can construct an ArchiveMember
168 friend class llvm::Archive;
172 /// This class defines the interface to LLVM Archive files. The Archive class
173 /// presents the archive file as an ilist of ArchiveMember objects. The members
174 /// can be rearranged in any fashion either by directly editing the ilist or by
175 /// using editing methods on the Archive class (recommended). The Archive
176 /// class also provides several ways of accessing the archive file for various
177 /// purposes such as editing and linking. Full symbol table support is provided
178 /// for loading only those files that resolve symbols. Note that read
179 /// performance of this library is _crucial_ for performance of JIT type
180 /// applications and the linkers. Consequently, the implementation of the class
181 /// is optimized for reading.
187 /// This is the ilist type over which users may iterate to examine
188 /// the contents of the archive
189 /// @brief The ilist type of ArchiveMembers that Archive contains.
190 typedef iplist<ArchiveMember> MembersList;
192 /// @brief Forward mutable iterator over ArchiveMember
193 typedef MembersList::iterator iterator;
195 /// @brief Forward immutable iterator over ArchiveMember
196 typedef MembersList::const_iterator const_iterator;
198 /// @brief Reverse mutable iterator over ArchiveMember
199 typedef std::reverse_iterator<iterator> reverse_iterator;
201 /// @brief Reverse immutable iterator over ArchiveMember
202 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
204 /// @brief The in-memory version of the symbol table
205 typedef std::map<std::string,unsigned> SymTabType;
208 /// @name ilist accessor methods
211 inline iterator begin() { return members.begin(); }
212 inline const_iterator begin() const { return members.begin(); }
213 inline iterator end () { return members.end(); }
214 inline const_iterator end () const { return members.end(); }
216 inline reverse_iterator rbegin() { return members.rbegin(); }
217 inline const_reverse_iterator rbegin() const { return members.rbegin(); }
218 inline reverse_iterator rend () { return members.rend(); }
219 inline const_reverse_iterator rend () const { return members.rend(); }
221 inline size_t size() const { return members.size(); }
222 inline bool empty() const { return members.empty(); }
223 inline const ArchiveMember& front() const { return members.front(); }
224 inline ArchiveMember& front() { return members.front(); }
225 inline const ArchiveMember& back() const { return members.back(); }
226 inline ArchiveMember& back() { return members.back(); }
229 /// @name ilist mutator methods
232 /// This method splices a \p src member from an archive (possibly \p this),
233 /// to a position just before the member given by \p dest in \p this. When
234 /// the archive is written, \p src will be written in its new location.
235 /// @brief Move a member to a new location
236 inline void splice(iterator dest, Archive& arch, iterator src)
237 { return members.splice(dest,arch.members,src); }
239 /// This method erases a \p target member from the archive. When the
240 /// archive is written, it will no longer contain \p target. The associated
241 /// ArchiveMember is deleted.
242 /// @brief Erase a member.
243 inline iterator erase(iterator target) { return members.erase(target); }
246 /// @name Constructors
249 /// Create an empty archive file and associate it with the \p Filename. This
250 /// method does not actually create the archive disk file. It creates an
251 /// empty Archive object. If the writeToDisk method is called, the archive
252 /// file \p Filename will be created at that point, with whatever content
253 /// the returned Archive object has at that time.
254 /// @returns An Archive* that represents the new archive file.
255 /// @brief Create an empty Archive.
256 static Archive *CreateEmpty(
257 StringRef Filename, ///< Name of the archive to (eventually) create.
258 LLVMContext &C ///< Context to use for global information
261 /// Open an existing archive and load its contents in preparation for
262 /// editing. After this call, the member ilist is completely populated based
263 /// on the contents of the archive file. You should use this form of open if
264 /// you intend to modify the archive or traverse its contents (e.g. for
266 /// @brief Open and load an archive file
267 static Archive *OpenAndLoad(
268 StringRef filePath, ///< The file path to open and load
269 LLVMContext &C, ///< The context to use for global information
270 std::string *ErrorMessage ///< An optional error string
273 /// This destructor cleans up the Archive object, releases all memory, and
274 /// closes files. It does nothing with the archive file on disk. If you
275 /// haven't used the writeToDisk method by the time the destructor is
276 /// called, all changes to the archive will be lost.
277 /// @brief Destruct in-memory archive
284 /// @returns the path to the archive file.
285 /// @brief Get the archive path.
286 StringRef getPath() { return archPath; }
288 /// This method is provided so that editing methods can be invoked directly
289 /// on the Archive's iplist of ArchiveMember. However, it is recommended
290 /// that the usual STL style iterator interface be used instead.
291 /// @returns the iplist of ArchiveMember
292 /// @brief Get the iplist of the members
293 MembersList& getMembers() { return members; }
295 /// This method returns the offset in the archive file to the first "real"
296 /// file member. Archive files, on disk, have a signature and might have a
297 /// symbol table that precedes the first actual file member. This method
298 /// allows you to determine what the size of those fields are.
299 /// @returns the offset to the first "real" file member in the archive.
300 /// @brief Get the offset to the first "real" file member in the archive.
301 unsigned getFirstFileOffset() { return firstFileOffset; }
307 /// This method is the only way to get the archive written to disk. It
308 /// creates or overwrites the file specified when \p this was created
309 /// or opened. The arguments provide options for writing the archive. If
310 /// \p CreateSymbolTable is true, the archive is scanned for bitcode files
311 /// and a symbol table of the externally visible function and global
312 /// variable names is created. If \p TruncateNames is true, the names of the
313 /// archive members will have their path component stripped and the file
314 /// name will be truncated at 15 characters. If \p Compress is specified,
315 /// all archive members will be compressed before being written. If
316 /// \p PrintSymTab is true, the symbol table will be printed to std::cout.
317 /// @returns true if an error occurred, \p error set to error message;
318 /// returns false if the writing succeeded.
319 /// @brief Write (possibly modified) archive contents to disk
321 std::string* ErrMessage=0 ///< If non-null, where error msg is set
324 /// This method adds a new file to the archive. The \p filename is examined
325 /// to determine just enough information to create an ArchiveMember object
326 /// which is then inserted into the Archive object's ilist at the location
327 /// given by \p where.
328 /// @returns true if an error occurred, false otherwise
329 /// @brief Add a file to the archive.
330 bool addFileBefore(StringRef filename, ///< The file to be added
331 iterator where, ///< Insertion point
332 std::string *ErrMsg ///< Optional error message location
336 /// @name Implementation
339 /// @brief Construct an Archive for \p filename and optionally map it
341 explicit Archive(StringRef filename, LLVMContext& C);
343 /// @returns A fully populated ArchiveMember or 0 if an error occurred.
344 /// @brief Parse the header of a member starting at \p At
345 ArchiveMember* parseMemberHeader(
346 const char*&At, ///< The pointer to the location we're parsing
347 const char*End, ///< The pointer to the end of the archive
348 std::string* error ///< Optional error message catcher
351 /// @param ErrMessage Set to address of a std::string to get error messages
352 /// @returns false on error
353 /// @brief Check that the archive signature is correct
354 bool checkSignature(std::string* ErrMessage);
356 /// @param ErrMessage Set to address of a std::string to get error messages
357 /// @returns false on error
358 /// @brief Load the entire archive.
359 bool loadArchive(std::string* ErrMessage);
361 /// @param ErrMessage Set to address of a std::string to get error messages
362 /// @returns false on error
363 /// @brief Load just the symbol table.
364 bool loadSymbolTable(std::string* ErrMessage);
366 /// Writes one ArchiveMember to an ofstream. If an error occurs, returns
367 /// false, otherwise true. If an error occurs and error is non-null then
368 /// it will be set to an error message.
369 /// @returns false if writing member succeeded,
370 /// returns true if writing member failed, \p error set to error message.
372 const ArchiveMember& member, ///< The member to be written
373 raw_fd_ostream& ARFile, ///< The file to write member onto
374 std::string* ErrMessage ///< If non-null, place were error msg is set
377 /// @brief Fill in an ArchiveMemberHeader from ArchiveMember.
378 bool fillHeader(const ArchiveMember&mbr,
379 ArchiveMemberHeader& hdr,int sz) const;
381 /// @brief Maps archive into memory
382 bool mapToMemory(std::string* ErrMsg);
384 /// @brief Frees all the members and unmaps the archive file.
385 void cleanUpMemory();
387 /// This type is used to keep track of bitcode modules loaded from the
388 /// symbol table. It maps the file offset to a pair that consists of the
389 /// associated ArchiveMember and the Module.
390 /// @brief Module mapping type
391 typedef std::map<unsigned,std::pair<Module*,ArchiveMember*> >
399 std::string archPath; ///< Path to the archive file we read/write
400 MembersList members; ///< The ilist of ArchiveMember
401 MemoryBuffer *mapfile; ///< Raw Archive contents mapped into memory
402 const char* base; ///< Base of the memory mapped file data
403 std::string strtab; ///< The string table for long file names
404 unsigned firstFileOffset; ///< Offset to first normal file.
405 ModuleMap modules; ///< The modules loaded via symbol lookup.
406 LLVMContext& Context; ///< This holds global data.
411 Archive() LLVM_DELETED_FUNCTION;
412 Archive(const Archive&) LLVM_DELETED_FUNCTION;
413 Archive& operator=(const Archive&) LLVM_DELETED_FUNCTION;
417 } // End llvm namespace