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 LLVM_BITCODE_ARCHIVE_H
18 #define LLVM_BITCODE_ARCHIVE_H
20 #include "llvm/ADT/ilist.h"
21 #include "llvm/ADT/ilist_node.h"
22 #include "llvm/System/Path.h"
29 // Forward declare classes
30 class ModuleProvider; // From VMCore
31 class Module; // From VMCore
32 class Archive; // Declared below
33 class ArchiveMemberHeader; // Internal implementation class
34 class LLVMContext; // Global data
36 /// This class is the main class manipulated by users of the Archive class. It
37 /// holds information about one member of the Archive. It is also the element
38 /// stored by the Archive's ilist, the Archive's main abstraction. Because of
39 /// the special requirements of archive files, users are not permitted to
40 /// construct ArchiveMember instances. You should obtain them from the methods
41 /// of the Archive class instead.
42 /// @brief This class represents a single archive member.
43 class ArchiveMember : public ilist_node<ArchiveMember> {
47 /// These flags are used internally by the archive member to specify various
48 /// characteristics of the member. The various "is" methods below provide
49 /// access to the flags. The flags are not user settable.
51 CompressedFlag = 1, ///< Member is a normal compressed file
52 SVR4SymbolTableFlag = 2, ///< Member is a SVR4 symbol table
53 BSD4SymbolTableFlag = 4, ///< Member is a BSD4 symbol table
54 LLVMSymbolTableFlag = 8, ///< Member is an LLVM symbol table
55 BitcodeFlag = 16, ///< Member is bitcode
56 HasPathFlag = 64, ///< Member has a full or partial path
57 HasLongFilenameFlag = 128, ///< Member uses the long filename syntax
58 StringTableFlag = 256 ///< Member is an ar(1) format string table
65 /// @returns the parent Archive instance
66 /// @brief Get the archive associated with this member
67 Archive* getArchive() const { return parent; }
69 /// @returns the path to the Archive's file
70 /// @brief Get the path to the archive member
71 const sys::Path& getPath() const { return path; }
73 /// The "user" is the owner of the file per Unix security. This may not
74 /// have any applicability on non-Unix systems but is a required component
75 /// of the "ar" file format.
76 /// @brief Get the user associated with this archive member.
77 unsigned getUser() const { return info.getUser(); }
79 /// The "group" is the owning group of the file per Unix security. This
80 /// may not have any applicability on non-Unix systems but is a required
81 /// component of the "ar" file format.
82 /// @brief Get the group associated with this archive member.
83 unsigned getGroup() const { return info.getGroup(); }
85 /// The "mode" specifies the access permissions for the file per Unix
86 /// security. This may not have any applicabiity on non-Unix systems but is
87 /// a required component of the "ar" file format.
88 /// @brief Get the permission mode associated with this archive member.
89 unsigned getMode() const { return info.getMode(); }
91 /// This method returns the time at which the archive member was last
92 /// modified when it was not in the archive.
93 /// @brief Get the time of last modification of the archive member.
94 sys::TimeValue getModTime() const { return info.getTimestamp(); }
96 /// @returns the size of the archive member in bytes.
97 /// @brief Get the size of the archive member.
98 uint64_t getSize() const { return info.getSize(); }
100 /// This method returns the total size of the archive member as it
101 /// appears on disk. This includes the file content, the header, the
102 /// long file name if any, and the padding.
103 /// @brief Get total on-disk member size.
104 unsigned getMemberSize() const;
106 /// This method will return a pointer to the in-memory content of the
107 /// archive member, if it is available. If the data has not been loaded
108 /// into memory, the return value will be null.
109 /// @returns a pointer to the member's data.
110 /// @brief Get the data content of the archive member
111 const void* getData() const { return data; }
113 /// This method determines if the member is a regular compressed file.
114 /// @returns true iff the archive member is a compressed regular file.
115 /// @brief Determine if the member is a compressed regular file.
116 bool isCompressed() const { return flags&CompressedFlag; }
118 /// @returns true iff the member is a SVR4 (non-LLVM) symbol table
119 /// @brief Determine if this member is a SVR4 symbol table.
120 bool isSVR4SymbolTable() const { return flags&SVR4SymbolTableFlag; }
122 /// @returns true iff the member is a BSD4.4 (non-LLVM) symbol table
123 /// @brief Determine if this member is a BSD4.4 symbol table.
124 bool isBSD4SymbolTable() const { return flags&BSD4SymbolTableFlag; }
126 /// @returns true iff the archive member is the LLVM symbol table
127 /// @brief Determine if this member is the LLVM symbol table.
128 bool isLLVMSymbolTable() const { return flags&LLVMSymbolTableFlag; }
130 /// @returns true iff the archive member is the ar(1) string table
131 /// @brief Determine if this member is the ar(1) string table.
132 bool isStringTable() const { return flags&StringTableFlag; }
134 /// @returns true iff the archive member is a bitcode file.
135 /// @brief Determine if this member is a bitcode file.
136 bool isBitcode() const { return flags&BitcodeFlag; }
138 /// @returns true iff the file name contains a path (directory) component.
139 /// @brief Determine if the member has a path
140 bool hasPath() const { return flags&HasPathFlag; }
142 /// Long filenames are an artifact of the ar(1) file format which allows
143 /// up to sixteen characters in its header and doesn't allow a path
144 /// separator character (/). To avoid this, a "long format" member name is
145 /// allowed that doesn't have this restriction. This method determines if
146 /// that "long format" is used for this member.
147 /// @returns true iff the file name uses the long form
148 /// @brief Determin if the member has a long file name
149 bool hasLongFilename() const { return flags&HasLongFilenameFlag; }
151 /// This method returns the status info (like Unix stat(2)) for the archive
152 /// member. The status info provides the file's size, permissions, and
153 /// modification time. The contents of the Path::StatusInfo structure, other
154 /// than the size and modification time, may not have utility on non-Unix
156 /// @returns the status info for the archive member
157 /// @brief Obtain the status info for the archive member
158 const sys::FileStatus &getFileStatus() const { return info; }
160 /// This method causes the archive member to be replaced with the contents
161 /// of the file specified by \p File. The contents of \p this will be
162 /// updated to reflect the new data from \p File. The \p File must exist and
163 /// be readable on entry to this method.
164 /// @returns true if an error occurred, false otherwise
165 /// @brief Replace contents of archive member with a new file.
166 bool replaceWith(const sys::Path &aFile, std::string* ErrMsg);
172 Archive* parent; ///< Pointer to parent archive
173 sys::PathWithStatus path; ///< Path of file containing the member
174 sys::FileStatus info; ///< Status info (size,mode,date)
175 unsigned flags; ///< Flags about the archive member
176 const void* data; ///< Data for the member
179 /// @name Constructors
182 /// The default constructor is only used by the Archive's iplist when it
183 /// constructs the list's sentry node.
187 /// Used internally by the Archive class to construct an ArchiveMember.
188 /// The contents of the ArchiveMember are filled out by the Archive class.
189 explicit ArchiveMember(Archive *PAR);
191 // So Archive can construct an ArchiveMember
192 friend class llvm::Archive;
196 /// This class defines the interface to LLVM Archive files. The Archive class
197 /// presents the archive file as an ilist of ArchiveMember objects. The members
198 /// can be rearranged in any fashion either by directly editing the ilist or by
199 /// using editing methods on the Archive class (recommended). The Archive
200 /// class also provides several ways of accessing the archive file for various
201 /// purposes such as editing and linking. Full symbol table support is provided
202 /// for loading only those files that resolve symbols. Note that read
203 /// performance of this library is _crucial_ for performance of JIT type
204 /// applications and the linkers. Consequently, the implementation of the class
205 /// is optimized for reading.
211 /// This is the ilist type over which users may iterate to examine
212 /// the contents of the archive
213 /// @brief The ilist type of ArchiveMembers that Archive contains.
214 typedef iplist<ArchiveMember> MembersList;
216 /// @brief Forward mutable iterator over ArchiveMember
217 typedef MembersList::iterator iterator;
219 /// @brief Forward immutable iterator over ArchiveMember
220 typedef MembersList::const_iterator const_iterator;
222 /// @brief Reverse mutable iterator over ArchiveMember
223 typedef std::reverse_iterator<iterator> reverse_iterator;
225 /// @brief Reverse immutable iterator over ArchiveMember
226 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
228 /// @brief The in-memory version of the symbol table
229 typedef std::map<std::string,unsigned> SymTabType;
232 /// @name ilist accessor methods
235 inline iterator begin() { return members.begin(); }
236 inline const_iterator begin() const { return members.begin(); }
237 inline iterator end () { return members.end(); }
238 inline const_iterator end () const { return members.end(); }
240 inline reverse_iterator rbegin() { return members.rbegin(); }
241 inline const_reverse_iterator rbegin() const { return members.rbegin(); }
242 inline reverse_iterator rend () { return members.rend(); }
243 inline const_reverse_iterator rend () const { return members.rend(); }
245 inline size_t size() const { return members.size(); }
246 inline bool empty() const { return members.empty(); }
247 inline const ArchiveMember& front() const { return members.front(); }
248 inline ArchiveMember& front() { return members.front(); }
249 inline const ArchiveMember& back() const { return members.back(); }
250 inline ArchiveMember& back() { return members.back(); }
253 /// @name ilist mutator methods
256 /// This method splices a \p src member from an archive (possibly \p this),
257 /// to a position just before the member given by \p dest in \p this. When
258 /// the archive is written, \p src will be written in its new location.
259 /// @brief Move a member to a new location
260 inline void splice(iterator dest, Archive& arch, iterator src)
261 { return members.splice(dest,arch.members,src); }
263 /// This method erases a \p target member from the archive. When the
264 /// archive is written, it will no longer contain \p target. The associated
265 /// ArchiveMember is deleted.
266 /// @brief Erase a member.
267 inline iterator erase(iterator target) { return members.erase(target); }
270 /// @name Constructors
273 /// Create an empty archive file and associate it with the \p Filename. This
274 /// method does not actually create the archive disk file. It creates an
275 /// empty Archive object. If the writeToDisk method is called, the archive
276 /// file \p Filename will be created at that point, with whatever content
277 /// the returned Archive object has at that time.
278 /// @returns An Archive* that represents the new archive file.
279 /// @brief Create an empty Archive.
280 static Archive* CreateEmpty(
281 const sys::Path& Filename,///< Name of the archive to (eventually) create.
282 LLVMContext& C ///< Context to use for global information
285 /// Open an existing archive and load its contents in preparation for
286 /// editing. After this call, the member ilist is completely populated based
287 /// on the contents of the archive file. You should use this form of open if
288 /// you intend to modify the archive or traverse its contents (e.g. for
290 /// @brief Open and load an archive file
291 static Archive* OpenAndLoad(
292 const sys::Path& filePath, ///< The file path to open and load
293 LLVMContext& C, ///< The context to use for global information
294 std::string* ErrorMessage ///< An optional error string
297 /// This method opens an existing archive file from \p Filename and reads in
298 /// its symbol table without reading in any of the archive's members. This
299 /// reduces both I/O and cpu time in opening the archive if it is to be used
300 /// solely for symbol lookup (e.g. during linking). The \p Filename must
301 /// exist and be an archive file or an exception will be thrown. This form
302 /// of opening the archive is intended for read-only operations that need to
303 /// locate members via the symbol table for link editing. Since the archve
304 /// members are not read by this method, the archive will appear empty upon
305 /// return. If editing operations are performed on the archive, they will
306 /// completely replace the contents of the archive! It is recommended that
307 /// if this form of opening the archive is used that only the symbol table
308 /// lookup methods (getSymbolTable, findModuleDefiningSymbol, and
309 /// findModulesDefiningSymbols) be used.
310 /// @throws std::string if an error occurs opening the file
311 /// @returns an Archive* that represents the archive file.
312 /// @brief Open an existing archive and load its symbols.
313 static Archive* OpenAndLoadSymbols(
314 const sys::Path& Filename, ///< Name of the archive file to open
315 LLVMContext& C, ///< The context to use for global info
316 std::string* ErrorMessage=0 ///< An optional error string
319 /// This destructor cleans up the Archive object, releases all memory, and
320 /// closes files. It does nothing with the archive file on disk. If you
321 /// haven't used the writeToDisk method by the time the destructor is
322 /// called, all changes to the archive will be lost.
323 /// @throws std::string if an error occurs
324 /// @brief Destruct in-memory archive
331 /// @returns the path to the archive file.
332 /// @brief Get the archive path.
333 const sys::Path& getPath() { return archPath; }
335 /// This method is provided so that editing methods can be invoked directly
336 /// on the Archive's iplist of ArchiveMember. However, it is recommended
337 /// that the usual STL style iterator interface be used instead.
338 /// @returns the iplist of ArchiveMember
339 /// @brief Get the iplist of the members
340 MembersList& getMembers() { return members; }
342 /// This method allows direct query of the Archive's symbol table. The
343 /// symbol table is a std::map of std::string (the symbol) to unsigned (the
344 /// file offset). Note that for efficiency reasons, the offset stored in
345 /// the symbol table is not the actual offset. It is the offset from the
346 /// beginning of the first "real" file member (after the symbol table). Use
347 /// the getFirstFileOffset() to obtain that offset and add this value to the
348 /// offset in the symbol table to obtain the real file offset. Note that
349 /// there is purposefully no interface provided by Archive to look up
350 /// members by their offset. Use the findModulesDefiningSymbols and
351 /// findModuleDefiningSymbol methods instead.
352 /// @returns the Archive's symbol table.
353 /// @brief Get the archive's symbol table
354 const SymTabType& getSymbolTable() { return symTab; }
356 /// This method returns the offset in the archive file to the first "real"
357 /// file member. Archive files, on disk, have a signature and might have a
358 /// symbol table that precedes the first actual file member. This method
359 /// allows you to determine what the size of those fields are.
360 /// @returns the offset to the first "real" file member in the archive.
361 /// @brief Get the offset to the first "real" file member in the archive.
362 unsigned getFirstFileOffset() { return firstFileOffset; }
364 /// This method will scan the archive for bitcode modules, interpret them
365 /// and return a vector of the instantiated modules in \p Modules. If an
366 /// error occurs, this method will return true. If \p ErrMessage is not null
367 /// and an error occurs, \p *ErrMessage will be set to a string explaining
368 /// the error that occurred.
369 /// @returns true if an error occurred
370 /// @brief Instantiate all the bitcode modules located in the archive
371 bool getAllModules(std::vector<Module*>& Modules, std::string* ErrMessage);
373 /// This accessor looks up the \p symbol in the archive's symbol table and
374 /// returns the associated module that defines that symbol. This method can
375 /// be called as many times as necessary. This is handy for linking the
376 /// archive into another module based on unresolved symbols. Note that the
377 /// ModuleProvider returned by this accessor should not be deleted by the
378 /// caller. It is managed internally by the Archive class. It is possible
379 /// that multiple calls to this accessor will return the same ModuleProvider
380 /// instance because the associated module defines multiple symbols.
381 /// @returns The ModuleProvider* found or null if the archive does not
382 /// contain a module that defines the \p symbol.
383 /// @brief Look up a module by symbol name.
384 ModuleProvider* findModuleDefiningSymbol(
385 const std::string& symbol, ///< Symbol to be sought
386 std::string* ErrMessage ///< Error message storage, if non-zero
389 /// This method is similar to findModuleDefiningSymbol but allows lookup of
390 /// more than one symbol at a time. If \p symbols contains a list of
391 /// undefined symbols in some module, then calling this method is like
392 /// making one complete pass through the archive to resolve symbols but is
393 /// more efficient than looking at the individual members. Note that on
394 /// exit, the symbols resolved by this method will be removed from \p
395 /// symbols to ensure they are not re-searched on a subsequent call. If
396 /// you need to retain the list of symbols, make a copy.
397 /// @brief Look up multiple symbols in the archive.
398 bool findModulesDefiningSymbols(
399 std::set<std::string>& symbols, ///< Symbols to be sought
400 std::set<ModuleProvider*>& modules, ///< The modules matching \p symbols
401 std::string* ErrMessage ///< Error msg storage, if non-zero
404 /// This method determines whether the archive is a properly formed llvm
405 /// bitcode archive. It first makes sure the symbol table has been loaded
406 /// and has a non-zero size. If it does, then it is an archive. If not,
407 /// then it tries to load all the bitcode modules of the archive. Finally,
408 /// it returns whether it was successfull.
409 /// @returns true if the archive is a proper llvm bitcode archive
410 /// @brief Determine whether the archive is a proper llvm bitcode archive.
411 bool isBitcodeArchive();
417 /// This method is the only way to get the archive written to disk. It
418 /// creates or overwrites the file specified when \p this was created
419 /// or opened. The arguments provide options for writing the archive. If
420 /// \p CreateSymbolTable is true, the archive is scanned for bitcode files
421 /// and a symbol table of the externally visible function and global
422 /// variable names is created. If \p TruncateNames is true, the names of the
423 /// archive members will have their path component stripped and the file
424 /// name will be truncated at 15 characters. If \p Compress is specified,
425 /// all archive members will be compressed before being written. If
426 /// \p PrintSymTab is true, the symbol table will be printed to std::cout.
427 /// @returns true if an error occurred, \p error set to error message
428 /// @returns false if the writing succeeded.
429 /// @brief Write (possibly modified) archive contents to disk
431 bool CreateSymbolTable=false, ///< Create Symbol table
432 bool TruncateNames=false, ///< Truncate the filename to 15 chars
433 bool Compress=false, ///< Compress files
434 std::string* ErrMessage=0 ///< If non-null, where error msg is set
437 /// This method adds a new file to the archive. The \p filename is examined
438 /// to determine just enough information to create an ArchiveMember object
439 /// which is then inserted into the Archive object's ilist at the location
440 /// given by \p where.
441 /// @returns true if an error occured, false otherwise
442 /// @brief Add a file to the archive.
444 const sys::Path& filename, ///< The file to be added
445 iterator where, ///< Insertion point
446 std::string* ErrMsg ///< Optional error message location
450 /// @name Implementation
453 /// @brief Construct an Archive for \p filename and optionally map it
455 explicit Archive(const sys::Path& filename, LLVMContext& C);
457 /// @param data The symbol table data to be parsed
458 /// @param len The length of the symbol table data
459 /// @param error Set to address of a std::string to get error messages
460 /// @returns false on error
461 /// @brief Parse the symbol table at \p data.
462 bool parseSymbolTable(const void* data,unsigned len,std::string* error);
464 /// @returns A fully populated ArchiveMember or 0 if an error occurred.
465 /// @brief Parse the header of a member starting at \p At
466 ArchiveMember* parseMemberHeader(
467 const char*&At, ///< The pointer to the location we're parsing
468 const char*End, ///< The pointer to the end of the archive
469 std::string* error ///< Optional error message catcher
472 /// @param ErrMessage Set to address of a std::string to get error messages
473 /// @returns false on error
474 /// @brief Check that the archive signature is correct
475 bool checkSignature(std::string* ErrMessage);
477 /// @param ErrMessage Set to address of a std::string to get error messages
478 /// @returns false on error
479 /// @brief Load the entire archive.
480 bool loadArchive(std::string* ErrMessage);
482 /// @param ErrMessage Set to address of a std::string to get error messages
483 /// @returns false on error
484 /// @brief Load just the symbol table.
485 bool loadSymbolTable(std::string* ErrMessage);
487 /// @brief Write the symbol table to an ofstream.
488 void writeSymbolTable(std::ofstream& ARFile);
490 /// Writes one ArchiveMember to an ofstream. If an error occurs, returns
491 /// false, otherwise true. If an error occurs and error is non-null then
492 /// it will be set to an error message.
493 /// @returns false Writing member succeeded
494 /// @returns true Writing member failed, \p error set to error message
496 const ArchiveMember& member, ///< The member to be written
497 std::ofstream& ARFile, ///< The file to write member onto
498 bool CreateSymbolTable, ///< Should symbol table be created?
499 bool TruncateNames, ///< Should names be truncated to 11 chars?
500 bool ShouldCompress, ///< Should the member be compressed?
501 std::string* ErrMessage ///< If non-null, place were error msg is set
504 /// @brief Fill in an ArchiveMemberHeader from ArchiveMember.
505 bool fillHeader(const ArchiveMember&mbr,
506 ArchiveMemberHeader& hdr,int sz, bool TruncateNames) const;
508 /// @brief Maps archive into memory
509 bool mapToMemory(std::string* ErrMsg);
511 /// @brief Frees all the members and unmaps the archive file.
512 void cleanUpMemory();
514 /// This type is used to keep track of bitcode modules loaded from the
515 /// symbol table. It maps the file offset to a pair that consists of the
516 /// associated ArchiveMember and the ModuleProvider.
517 /// @brief Module mapping type
518 typedef std::map<unsigned,std::pair<ModuleProvider*,ArchiveMember*> >
526 sys::Path archPath; ///< Path to the archive file we read/write
527 MembersList members; ///< The ilist of ArchiveMember
528 MemoryBuffer *mapfile; ///< Raw Archive contents mapped into memory
529 const char* base; ///< Base of the memory mapped file data
530 SymTabType symTab; ///< The symbol table
531 std::string strtab; ///< The string table for long file names
532 unsigned symTabSize; ///< Size in bytes of symbol table
533 unsigned firstFileOffset; ///< Offset to first normal file.
534 ModuleMap modules; ///< The modules loaded via symbol lookup.
535 ArchiveMember* foreignST; ///< This holds the foreign symbol table.
536 LLVMContext& Context; ///< This holds global data.
541 Archive(); ///< Do not implement
542 Archive(const Archive&); ///< Do not implement
543 Archive& operator=(const Archive&); ///< Do not implement
547 } // End llvm namespace