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 BitcodeFlag = 4, ///< Member is bitcode
56 HasLongFilenameFlag = 8, ///< Member uses the long filename syntax
57 StringTableFlag = 16 ///< Member is an ar(1) format string table
64 /// @returns the parent Archive instance
65 /// @brief Get the archive associated with this member
66 Archive* getArchive() const { return parent; }
68 /// @returns the path to the Archive's file
69 /// @brief Get the path to the archive member
70 StringRef getPath() const { return path; }
72 /// The "user" is the owner of the file per Unix security. This may not
73 /// have any applicability on non-Unix systems but is a required component
74 /// of the "ar" file format.
75 /// @brief Get the user associated with this archive member.
76 unsigned getUser() const { return User; }
78 /// The "group" is the owning group of the file per Unix security. This
79 /// may not have any applicability on non-Unix systems but is a required
80 /// component of the "ar" file format.
81 /// @brief Get the group associated with this archive member.
82 unsigned getGroup() const { return Group; }
84 /// The "mode" specifies the access permissions for the file per Unix
85 /// security. This may not have any applicability on non-Unix systems but is
86 /// a required component of the "ar" file format.
87 /// @brief Get the permission mode associated with this archive member.
88 unsigned getMode() const { return Mode; }
90 /// This method returns the time at which the archive member was last
91 /// modified when it was not in the archive.
92 /// @brief Get the time of last modification of the archive member.
93 sys::TimeValue getModTime() const { return ModTime; }
95 /// @returns the size of the archive member in bytes.
96 /// @brief Get the size of the archive member.
97 uint64_t getSize() const { return Size; }
99 /// This method returns the total size of the archive member as it
100 /// appears on disk. This includes the file content, the header, the
101 /// long file name if any, and the padding.
102 /// @brief Get total on-disk member size.
103 unsigned getMemberSize() const;
105 /// This method will return a pointer to the in-memory content of the
106 /// archive member, if it is available. If the data has not been loaded
107 /// into memory, the return value will be null.
108 /// @returns a pointer to the member's data.
109 /// @brief Get the data content of the archive member
110 const char* getData() const { return data; }
112 /// @returns true iff the member is a SVR4 (non-LLVM) symbol table
113 /// @brief Determine if this member is a SVR4 symbol table.
114 bool isSVR4SymbolTable() const { return flags&SVR4SymbolTableFlag; }
116 /// @returns true iff the member is a BSD4.4 (non-LLVM) symbol table
117 /// @brief Determine if this member is a BSD4.4 symbol table.
118 bool isBSD4SymbolTable() const { return flags&BSD4SymbolTableFlag; }
120 /// @returns true iff the archive member is the ar(1) string table
121 /// @brief Determine if this member is the ar(1) string table.
122 bool isStringTable() const { return flags&StringTableFlag; }
124 /// @returns true iff the archive member is a bitcode file.
125 /// @brief Determine if this member is a bitcode file.
126 bool isBitcode() const { return flags&BitcodeFlag; }
128 /// Long filenames are an artifact of the ar(1) file format which allows
129 /// up to sixteen characters in its header and doesn't allow a path
130 /// separator character (/). To avoid this, a "long format" member name is
131 /// allowed that doesn't have this restriction. This method determines if
132 /// that "long format" is used for this member.
133 /// @returns true iff the file name uses the long form
134 /// @brief Determine if the member has a long file name
135 bool hasLongFilename() const { return flags&HasLongFilenameFlag; }
137 /// This method causes the archive member to be replaced with the contents
138 /// of the file specified by \p File. The contents of \p this will be
139 /// updated to reflect the new data from \p File. The \p File must exist and
140 /// be readable on entry to this method.
141 /// @returns true if an error occurred, false otherwise
142 /// @brief Replace contents of archive member with a new file.
143 bool replaceWith(StringRef aFile, std::string* ErrMsg);
149 Archive *parent; ///< Pointer to parent archive
150 std::string path; ///< Path of file containing the member
154 sys::TimeValue ModTime;
156 unsigned flags; ///< Flags about the archive member
157 const char *data; ///< Data for the member
160 /// @name Constructors
163 /// The default constructor is only used by the Archive's iplist when it
164 /// constructs the list's sentry node.
168 /// Used internally by the Archive class to construct an ArchiveMember.
169 /// The contents of the ArchiveMember are filled out by the Archive class.
170 explicit ArchiveMember(Archive *PAR);
172 // So Archive can construct an ArchiveMember
173 friend class llvm::Archive;
177 /// This class defines the interface to LLVM Archive files. The Archive class
178 /// presents the archive file as an ilist of ArchiveMember objects. The members
179 /// can be rearranged in any fashion either by directly editing the ilist or by
180 /// using editing methods on the Archive class (recommended). The Archive
181 /// class also provides several ways of accessing the archive file for various
182 /// purposes such as editing and linking. Full symbol table support is provided
183 /// for loading only those files that resolve symbols. Note that read
184 /// performance of this library is _crucial_ for performance of JIT type
185 /// applications and the linkers. Consequently, the implementation of the class
186 /// is optimized for reading.
192 /// This is the ilist type over which users may iterate to examine
193 /// the contents of the archive
194 /// @brief The ilist type of ArchiveMembers that Archive contains.
195 typedef iplist<ArchiveMember> MembersList;
197 /// @brief Forward mutable iterator over ArchiveMember
198 typedef MembersList::iterator iterator;
200 /// @brief Forward immutable iterator over ArchiveMember
201 typedef MembersList::const_iterator const_iterator;
203 /// @brief Reverse mutable iterator over ArchiveMember
204 typedef std::reverse_iterator<iterator> reverse_iterator;
206 /// @brief Reverse immutable iterator over ArchiveMember
207 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
209 /// @brief The in-memory version of the symbol table
210 typedef std::map<std::string,unsigned> SymTabType;
213 /// @name ilist accessor methods
216 inline iterator begin() { return members.begin(); }
217 inline const_iterator begin() const { return members.begin(); }
218 inline iterator end () { return members.end(); }
219 inline const_iterator end () const { return members.end(); }
221 inline reverse_iterator rbegin() { return members.rbegin(); }
222 inline const_reverse_iterator rbegin() const { return members.rbegin(); }
223 inline reverse_iterator rend () { return members.rend(); }
224 inline const_reverse_iterator rend () const { return members.rend(); }
226 inline size_t size() const { return members.size(); }
227 inline bool empty() const { return members.empty(); }
228 inline const ArchiveMember& front() const { return members.front(); }
229 inline ArchiveMember& front() { return members.front(); }
230 inline const ArchiveMember& back() const { return members.back(); }
231 inline ArchiveMember& back() { return members.back(); }
234 /// @name ilist mutator methods
237 /// This method splices a \p src member from an archive (possibly \p this),
238 /// to a position just before the member given by \p dest in \p this. When
239 /// the archive is written, \p src will be written in its new location.
240 /// @brief Move a member to a new location
241 inline void splice(iterator dest, Archive& arch, iterator src)
242 { return members.splice(dest,arch.members,src); }
244 /// This method erases a \p target member from the archive. When the
245 /// archive is written, it will no longer contain \p target. The associated
246 /// ArchiveMember is deleted.
247 /// @brief Erase a member.
248 inline iterator erase(iterator target) { return members.erase(target); }
251 /// @name Constructors
254 /// Create an empty archive file and associate it with the \p Filename. This
255 /// method does not actually create the archive disk file. It creates an
256 /// empty Archive object. If the writeToDisk method is called, the archive
257 /// file \p Filename will be created at that point, with whatever content
258 /// the returned Archive object has at that time.
259 /// @returns An Archive* that represents the new archive file.
260 /// @brief Create an empty Archive.
261 static Archive *CreateEmpty(
262 StringRef Filename, ///< Name of the archive to (eventually) create.
263 LLVMContext &C ///< Context to use for global information
266 /// Open an existing archive and load its contents in preparation for
267 /// editing. After this call, the member ilist is completely populated based
268 /// on the contents of the archive file. You should use this form of open if
269 /// you intend to modify the archive or traverse its contents (e.g. for
271 /// @brief Open and load an archive file
272 static Archive *OpenAndLoad(
273 StringRef filePath, ///< The file path to open and load
274 LLVMContext &C, ///< The context to use for global information
275 std::string *ErrorMessage ///< An optional error string
278 /// This destructor cleans up the Archive object, releases all memory, and
279 /// closes files. It does nothing with the archive file on disk. If you
280 /// haven't used the writeToDisk method by the time the destructor is
281 /// called, all changes to the archive will be lost.
282 /// @brief Destruct in-memory archive
289 /// @returns the path to the archive file.
290 /// @brief Get the archive path.
291 StringRef getPath() { return archPath; }
293 /// This method is provided so that editing methods can be invoked directly
294 /// on the Archive's iplist of ArchiveMember. However, it is recommended
295 /// that the usual STL style iterator interface be used instead.
296 /// @returns the iplist of ArchiveMember
297 /// @brief Get the iplist of the members
298 MembersList& getMembers() { return members; }
300 /// This method returns the offset in the archive file to the first "real"
301 /// file member. Archive files, on disk, have a signature and might have a
302 /// symbol table that precedes the first actual file member. This method
303 /// allows you to determine what the size of those fields are.
304 /// @returns the offset to the first "real" file member in the archive.
305 /// @brief Get the offset to the first "real" file member in the archive.
306 unsigned getFirstFileOffset() { return firstFileOffset; }
312 /// This method is the only way to get the archive written to disk. It
313 /// creates or overwrites the file specified when \p this was created
314 /// or opened. The arguments provide options for writing the archive. If
315 /// \p CreateSymbolTable is true, the archive is scanned for bitcode files
316 /// and a symbol table of the externally visible function and global
317 /// variable names is created. If \p TruncateNames is true, the names of the
318 /// archive members will have their path component stripped and the file
319 /// name will be truncated at 15 characters. If \p Compress is specified,
320 /// all archive members will be compressed before being written. If
321 /// \p PrintSymTab is true, the symbol table will be printed to std::cout.
322 /// @returns true if an error occurred, \p error set to error message;
323 /// returns false if the writing succeeded.
324 /// @brief Write (possibly modified) archive contents to disk
326 bool TruncateNames=false, ///< Truncate the filename to 15 chars
327 std::string* ErrMessage=0 ///< If non-null, where error msg is set
330 /// This method adds a new file to the archive. The \p filename is examined
331 /// to determine just enough information to create an ArchiveMember object
332 /// which is then inserted into the Archive object's ilist at the location
333 /// given by \p where.
334 /// @returns true if an error occurred, false otherwise
335 /// @brief Add a file to the archive.
336 bool addFileBefore(StringRef filename, ///< The file to be added
337 iterator where, ///< Insertion point
338 std::string *ErrMsg ///< Optional error message location
342 /// @name Implementation
345 /// @brief Construct an Archive for \p filename and optionally map it
347 explicit Archive(StringRef filename, LLVMContext& C);
349 /// @returns A fully populated ArchiveMember or 0 if an error occurred.
350 /// @brief Parse the header of a member starting at \p At
351 ArchiveMember* parseMemberHeader(
352 const char*&At, ///< The pointer to the location we're parsing
353 const char*End, ///< The pointer to the end of the archive
354 std::string* error ///< Optional error message catcher
357 /// @param ErrMessage Set to address of a std::string to get error messages
358 /// @returns false on error
359 /// @brief Check that the archive signature is correct
360 bool checkSignature(std::string* ErrMessage);
362 /// @param ErrMessage Set to address of a std::string to get error messages
363 /// @returns false on error
364 /// @brief Load the entire archive.
365 bool loadArchive(std::string* ErrMessage);
367 /// @param ErrMessage Set to address of a std::string to get error messages
368 /// @returns false on error
369 /// @brief Load just the symbol table.
370 bool loadSymbolTable(std::string* ErrMessage);
372 /// Writes one ArchiveMember to an ofstream. If an error occurs, returns
373 /// false, otherwise true. If an error occurs and error is non-null then
374 /// it will be set to an error message.
375 /// @returns false if writing member succeeded,
376 /// returns true if writing member failed, \p error set to error message.
378 const ArchiveMember& member, ///< The member to be written
379 raw_fd_ostream& ARFile, ///< The file to write member onto
380 bool TruncateNames, ///< Should names be truncated to 11 chars?
381 std::string* ErrMessage ///< If non-null, place were error msg is set
384 /// @brief Fill in an ArchiveMemberHeader from ArchiveMember.
385 bool fillHeader(const ArchiveMember&mbr,
386 ArchiveMemberHeader& hdr,int sz, bool TruncateNames) const;
388 /// @brief Maps archive into memory
389 bool mapToMemory(std::string* ErrMsg);
391 /// @brief Frees all the members and unmaps the archive file.
392 void cleanUpMemory();
394 /// This type is used to keep track of bitcode modules loaded from the
395 /// symbol table. It maps the file offset to a pair that consists of the
396 /// associated ArchiveMember and the Module.
397 /// @brief Module mapping type
398 typedef std::map<unsigned,std::pair<Module*,ArchiveMember*> >
406 std::string archPath; ///< Path to the archive file we read/write
407 MembersList members; ///< The ilist of ArchiveMember
408 MemoryBuffer *mapfile; ///< Raw Archive contents mapped into memory
409 const char* base; ///< Base of the memory mapped file data
410 std::string strtab; ///< The string table for long file names
411 unsigned firstFileOffset; ///< Offset to first normal file.
412 ModuleMap modules; ///< The modules loaded via symbol lookup.
413 LLVMContext& Context; ///< This holds global data.
418 Archive() LLVM_DELETED_FUNCTION;
419 Archive(const Archive&) LLVM_DELETED_FUNCTION;
420 Archive& operator=(const Archive&) LLVM_DELETED_FUNCTION;
424 } // End llvm namespace