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Diffstat (limited to 'include/llvm/Bitcode/Archive.h')
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diff --git a/include/llvm/Bitcode/Archive.h b/include/llvm/Bitcode/Archive.h new file mode 100644 index 0000000..a3631ac --- /dev/null +++ b/include/llvm/Bitcode/Archive.h @@ -0,0 +1,545 @@ +//===-- llvm/Bitcode/Archive.h - LLVM Bitcode Archive -----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This header file declares the Archive and ArchiveMember classes that provide +// manipulation of LLVM Archive files. The implementation is provided by the +// lib/Bitcode/Archive library. This library is used to read and write +// archive (*.a) files that contain LLVM bitcode files (or others). +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_BITCODE_ARCHIVE_H +#define LLVM_BITCODE_ARCHIVE_H + +#include "llvm/ADT/ilist.h" +#include "llvm/ADT/ilist_node.h" +#include "llvm/System/Path.h" +#include <map> +#include <set> +#include <fstream> + +namespace llvm { + class MemoryBuffer; + +// Forward declare classes +class ModuleProvider; // From VMCore +class Module; // From VMCore +class Archive; // Declared below +class ArchiveMemberHeader; // Internal implementation class + +/// This class is the main class manipulated by users of the Archive class. It +/// holds information about one member of the Archive. It is also the element +/// stored by the Archive's ilist, the Archive's main abstraction. Because of +/// the special requirements of archive files, users are not permitted to +/// construct ArchiveMember instances. You should obtain them from the methods +/// of the Archive class instead. +/// @brief This class represents a single archive member. +class ArchiveMember : public ilist_node<ArchiveMember> { + /// @name Types + /// @{ + public: + /// These flags are used internally by the archive member to specify various + /// characteristics of the member. The various "is" methods below provide + /// access to the flags. The flags are not user settable. + enum Flags { + CompressedFlag = 1, ///< Member is a normal compressed file + SVR4SymbolTableFlag = 2, ///< Member is a SVR4 symbol table + BSD4SymbolTableFlag = 4, ///< Member is a BSD4 symbol table + LLVMSymbolTableFlag = 8, ///< Member is an LLVM symbol table + BitcodeFlag = 16, ///< Member is bitcode + HasPathFlag = 64, ///< Member has a full or partial path + HasLongFilenameFlag = 128, ///< Member uses the long filename syntax + StringTableFlag = 256 ///< Member is an ar(1) format string table + }; + + /// @} + /// @name Accessors + /// @{ + public: + /// @returns the parent Archive instance + /// @brief Get the archive associated with this member + Archive* getArchive() const { return parent; } + + /// @returns the path to the Archive's file + /// @brief Get the path to the archive member + const sys::Path& getPath() const { return path; } + + /// The "user" is the owner of the file per Unix security. This may not + /// have any applicability on non-Unix systems but is a required component + /// of the "ar" file format. + /// @brief Get the user associated with this archive member. + unsigned getUser() const { return info.getUser(); } + + /// The "group" is the owning group of the file per Unix security. This + /// may not have any applicability on non-Unix systems but is a required + /// component of the "ar" file format. + /// @brief Get the group associated with this archive member. + unsigned getGroup() const { return info.getGroup(); } + + /// The "mode" specifies the access permissions for the file per Unix + /// security. This may not have any applicabiity on non-Unix systems but is + /// a required component of the "ar" file format. + /// @brief Get the permission mode associated with this archive member. + unsigned getMode() const { return info.getMode(); } + + /// This method returns the time at which the archive member was last + /// modified when it was not in the archive. + /// @brief Get the time of last modification of the archive member. + sys::TimeValue getModTime() const { return info.getTimestamp(); } + + /// @returns the size of the archive member in bytes. + /// @brief Get the size of the archive member. + uint64_t getSize() const { return info.getSize(); } + + /// This method returns the total size of the archive member as it + /// appears on disk. This includes the file content, the header, the + /// long file name if any, and the padding. + /// @brief Get total on-disk member size. + unsigned getMemberSize() const; + + /// This method will return a pointer to the in-memory content of the + /// archive member, if it is available. If the data has not been loaded + /// into memory, the return value will be null. + /// @returns a pointer to the member's data. + /// @brief Get the data content of the archive member + const void* getData() const { return data; } + + /// This method determines if the member is a regular compressed file. + /// @returns true iff the archive member is a compressed regular file. + /// @brief Determine if the member is a compressed regular file. + bool isCompressed() const { return flags&CompressedFlag; } + + /// @returns true iff the member is a SVR4 (non-LLVM) symbol table + /// @brief Determine if this member is a SVR4 symbol table. + bool isSVR4SymbolTable() const { return flags&SVR4SymbolTableFlag; } + + /// @returns true iff the member is a BSD4.4 (non-LLVM) symbol table + /// @brief Determine if this member is a BSD4.4 symbol table. + bool isBSD4SymbolTable() const { return flags&BSD4SymbolTableFlag; } + + /// @returns true iff the archive member is the LLVM symbol table + /// @brief Determine if this member is the LLVM symbol table. + bool isLLVMSymbolTable() const { return flags&LLVMSymbolTableFlag; } + + /// @returns true iff the archive member is the ar(1) string table + /// @brief Determine if this member is the ar(1) string table. + bool isStringTable() const { return flags&StringTableFlag; } + + /// @returns true iff the archive member is a bitcode file. + /// @brief Determine if this member is a bitcode file. + bool isBitcode() const { return flags&BitcodeFlag; } + + /// @returns true iff the file name contains a path (directory) component. + /// @brief Determine if the member has a path + bool hasPath() const { return flags&HasPathFlag; } + + /// Long filenames are an artifact of the ar(1) file format which allows + /// up to sixteen characters in its header and doesn't allow a path + /// separator character (/). To avoid this, a "long format" member name is + /// allowed that doesn't have this restriction. This method determines if + /// that "long format" is used for this member. + /// @returns true iff the file name uses the long form + /// @brief Determin if the member has a long file name + bool hasLongFilename() const { return flags&HasLongFilenameFlag; } + + /// This method returns the status info (like Unix stat(2)) for the archive + /// member. The status info provides the file's size, permissions, and + /// modification time. The contents of the Path::StatusInfo structure, other + /// than the size and modification time, may not have utility on non-Unix + /// systems. + /// @returns the status info for the archive member + /// @brief Obtain the status info for the archive member + const sys::FileStatus &getFileStatus() const { return info; } + + /// This method causes the archive member to be replaced with the contents + /// of the file specified by \p File. The contents of \p this will be + /// updated to reflect the new data from \p File. The \p File must exist and + /// be readable on entry to this method. + /// @returns true if an error occurred, false otherwise + /// @brief Replace contents of archive member with a new file. + bool replaceWith(const sys::Path &aFile, std::string* ErrMsg); + + /// @} + /// @name Data + /// @{ + private: + Archive* parent; ///< Pointer to parent archive + sys::PathWithStatus path; ///< Path of file containing the member + sys::FileStatus info; ///< Status info (size,mode,date) + unsigned flags; ///< Flags about the archive member + const void* data; ///< Data for the member + + /// @} + /// @name Constructors + /// @{ + public: + /// The default constructor is only used by the Archive's iplist when it + /// constructs the list's sentry node. + ArchiveMember(); + + private: + /// Used internally by the Archive class to construct an ArchiveMember. + /// The contents of the ArchiveMember are filled out by the Archive class. + explicit ArchiveMember(Archive *PAR); + + // So Archive can construct an ArchiveMember + friend class llvm::Archive; + /// @} +}; + +/// This class defines the interface to LLVM Archive files. The Archive class +/// presents the archive file as an ilist of ArchiveMember objects. The members +/// can be rearranged in any fashion either by directly editing the ilist or by +/// using editing methods on the Archive class (recommended). The Archive +/// class also provides several ways of accessing the archive file for various +/// purposes such as editing and linking. Full symbol table support is provided +/// for loading only those files that resolve symbols. Note that read +/// performance of this library is _crucial_ for performance of JIT type +/// applications and the linkers. Consequently, the implementation of the class +/// is optimized for reading. +class Archive { + + /// @name Types + /// @{ + public: + /// This is the ilist type over which users may iterate to examine + /// the contents of the archive + /// @brief The ilist type of ArchiveMembers that Archive contains. + typedef iplist<ArchiveMember> MembersList; + + /// @brief Forward mutable iterator over ArchiveMember + typedef MembersList::iterator iterator; + + /// @brief Forward immutable iterator over ArchiveMember + typedef MembersList::const_iterator const_iterator; + + /// @brief Reverse mutable iterator over ArchiveMember + typedef std::reverse_iterator<iterator> reverse_iterator; + + /// @brief Reverse immutable iterator over ArchiveMember + typedef std::reverse_iterator<const_iterator> const_reverse_iterator; + + /// @brief The in-memory version of the symbol table + typedef std::map<std::string,unsigned> SymTabType; + + /// @} + /// @name ilist accessor methods + /// @{ + public: + inline iterator begin() { return members.begin(); } + inline const_iterator begin() const { return members.begin(); } + inline iterator end () { return members.end(); } + inline const_iterator end () const { return members.end(); } + + inline reverse_iterator rbegin() { return members.rbegin(); } + inline const_reverse_iterator rbegin() const { return members.rbegin(); } + inline reverse_iterator rend () { return members.rend(); } + inline const_reverse_iterator rend () const { return members.rend(); } + + inline size_t size() const { return members.size(); } + inline bool empty() const { return members.empty(); } + inline const ArchiveMember& front() const { return members.front(); } + inline ArchiveMember& front() { return members.front(); } + inline const ArchiveMember& back() const { return members.back(); } + inline ArchiveMember& back() { return members.back(); } + + /// @} + /// @name ilist mutator methods + /// @{ + public: + /// This method splices a \p src member from an archive (possibly \p this), + /// to a position just before the member given by \p dest in \p this. When + /// the archive is written, \p src will be written in its new location. + /// @brief Move a member to a new location + inline void splice(iterator dest, Archive& arch, iterator src) + { return members.splice(dest,arch.members,src); } + + /// This method erases a \p target member from the archive. When the + /// archive is written, it will no longer contain \p target. The associated + /// ArchiveMember is deleted. + /// @brief Erase a member. + inline iterator erase(iterator target) { return members.erase(target); } + + /// @} + /// @name Constructors + /// @{ + public: + /// Create an empty archive file and associate it with the \p Filename. This + /// method does not actually create the archive disk file. It creates an + /// empty Archive object. If the writeToDisk method is called, the archive + /// file \p Filename will be created at that point, with whatever content + /// the returned Archive object has at that time. + /// @returns An Archive* that represents the new archive file. + /// @brief Create an empty Archive. + static Archive* CreateEmpty( + const sys::Path& Filename ///< Name of the archive to (eventually) create. + ); + + /// Open an existing archive and load its contents in preparation for + /// editing. After this call, the member ilist is completely populated based + /// on the contents of the archive file. You should use this form of open if + /// you intend to modify the archive or traverse its contents (e.g. for + /// printing). + /// @brief Open and load an archive file + static Archive* OpenAndLoad( + const sys::Path& filePath, ///< The file path to open and load + std::string* ErrorMessage ///< An optional error string + ); + + /// This method opens an existing archive file from \p Filename and reads in + /// its symbol table without reading in any of the archive's members. This + /// reduces both I/O and cpu time in opening the archive if it is to be used + /// solely for symbol lookup (e.g. during linking). The \p Filename must + /// exist and be an archive file or an exception will be thrown. This form + /// of opening the archive is intended for read-only operations that need to + /// locate members via the symbol table for link editing. Since the archve + /// members are not read by this method, the archive will appear empty upon + /// return. If editing operations are performed on the archive, they will + /// completely replace the contents of the archive! It is recommended that + /// if this form of opening the archive is used that only the symbol table + /// lookup methods (getSymbolTable, findModuleDefiningSymbol, and + /// findModulesDefiningSymbols) be used. + /// @throws std::string if an error occurs opening the file + /// @returns an Archive* that represents the archive file. + /// @brief Open an existing archive and load its symbols. + static Archive* OpenAndLoadSymbols( + const sys::Path& Filename, ///< Name of the archive file to open + std::string* ErrorMessage=0 ///< An optional error string + ); + + /// This destructor cleans up the Archive object, releases all memory, and + /// closes files. It does nothing with the archive file on disk. If you + /// haven't used the writeToDisk method by the time the destructor is + /// called, all changes to the archive will be lost. + /// @throws std::string if an error occurs + /// @brief Destruct in-memory archive + ~Archive(); + + /// @} + /// @name Accessors + /// @{ + public: + /// @returns the path to the archive file. + /// @brief Get the archive path. + const sys::Path& getPath() { return archPath; } + + /// This method is provided so that editing methods can be invoked directly + /// on the Archive's iplist of ArchiveMember. However, it is recommended + /// that the usual STL style iterator interface be used instead. + /// @returns the iplist of ArchiveMember + /// @brief Get the iplist of the members + MembersList& getMembers() { return members; } + + /// This method allows direct query of the Archive's symbol table. The + /// symbol table is a std::map of std::string (the symbol) to unsigned (the + /// file offset). Note that for efficiency reasons, the offset stored in + /// the symbol table is not the actual offset. It is the offset from the + /// beginning of the first "real" file member (after the symbol table). Use + /// the getFirstFileOffset() to obtain that offset and add this value to the + /// offset in the symbol table to obtain the real file offset. Note that + /// there is purposefully no interface provided by Archive to look up + /// members by their offset. Use the findModulesDefiningSymbols and + /// findModuleDefiningSymbol methods instead. + /// @returns the Archive's symbol table. + /// @brief Get the archive's symbol table + const SymTabType& getSymbolTable() { return symTab; } + + /// This method returns the offset in the archive file to the first "real" + /// file member. Archive files, on disk, have a signature and might have a + /// symbol table that precedes the first actual file member. This method + /// allows you to determine what the size of those fields are. + /// @returns the offset to the first "real" file member in the archive. + /// @brief Get the offset to the first "real" file member in the archive. + unsigned getFirstFileOffset() { return firstFileOffset; } + + /// This method will scan the archive for bitcode modules, interpret them + /// and return a vector of the instantiated modules in \p Modules. If an + /// error occurs, this method will return true. If \p ErrMessage is not null + /// and an error occurs, \p *ErrMessage will be set to a string explaining + /// the error that occurred. + /// @returns true if an error occurred + /// @brief Instantiate all the bitcode modules located in the archive + bool getAllModules(std::vector<Module*>& Modules, std::string* ErrMessage); + + /// This accessor looks up the \p symbol in the archive's symbol table and + /// returns the associated module that defines that symbol. This method can + /// be called as many times as necessary. This is handy for linking the + /// archive into another module based on unresolved symbols. Note that the + /// ModuleProvider returned by this accessor should not be deleted by the + /// caller. It is managed internally by the Archive class. It is possible + /// that multiple calls to this accessor will return the same ModuleProvider + /// instance because the associated module defines multiple symbols. + /// @returns The ModuleProvider* found or null if the archive does not + /// contain a module that defines the \p symbol. + /// @brief Look up a module by symbol name. + ModuleProvider* findModuleDefiningSymbol( + const std::string& symbol, ///< Symbol to be sought + std::string* ErrMessage ///< Error message storage, if non-zero + ); + + /// This method is similar to findModuleDefiningSymbol but allows lookup of + /// more than one symbol at a time. If \p symbols contains a list of + /// undefined symbols in some module, then calling this method is like + /// making one complete pass through the archive to resolve symbols but is + /// more efficient than looking at the individual members. Note that on + /// exit, the symbols resolved by this method will be removed from \p + /// symbols to ensure they are not re-searched on a subsequent call. If + /// you need to retain the list of symbols, make a copy. + /// @brief Look up multiple symbols in the archive. + bool findModulesDefiningSymbols( + std::set<std::string>& symbols, ///< Symbols to be sought + std::set<ModuleProvider*>& modules, ///< The modules matching \p symbols + std::string* ErrMessage ///< Error msg storage, if non-zero + ); + + /// This method determines whether the archive is a properly formed llvm + /// bitcode archive. It first makes sure the symbol table has been loaded + /// and has a non-zero size. If it does, then it is an archive. If not, + /// then it tries to load all the bitcode modules of the archive. Finally, + /// it returns whether it was successfull. + /// @returns true if the archive is a proper llvm bitcode archive + /// @brief Determine whether the archive is a proper llvm bitcode archive. + bool isBitcodeArchive(); + + /// @} + /// @name Mutators + /// @{ + public: + /// This method is the only way to get the archive written to disk. It + /// creates or overwrites the file specified when \p this was created + /// or opened. The arguments provide options for writing the archive. If + /// \p CreateSymbolTable is true, the archive is scanned for bitcode files + /// and a symbol table of the externally visible function and global + /// variable names is created. If \p TruncateNames is true, the names of the + /// archive members will have their path component stripped and the file + /// name will be truncated at 15 characters. If \p Compress is specified, + /// all archive members will be compressed before being written. If + /// \p PrintSymTab is true, the symbol table will be printed to std::cout. + /// @returns true if an error occurred, \p error set to error message + /// @returns false if the writing succeeded. + /// @brief Write (possibly modified) archive contents to disk + bool writeToDisk( + bool CreateSymbolTable=false, ///< Create Symbol table + bool TruncateNames=false, ///< Truncate the filename to 15 chars + bool Compress=false, ///< Compress files + std::string* ErrMessage=0 ///< If non-null, where error msg is set + ); + + /// This method adds a new file to the archive. The \p filename is examined + /// to determine just enough information to create an ArchiveMember object + /// which is then inserted into the Archive object's ilist at the location + /// given by \p where. + /// @returns true if an error occured, false otherwise + /// @brief Add a file to the archive. + bool addFileBefore( + const sys::Path& filename, ///< The file to be added + iterator where, ///< Insertion point + std::string* ErrMsg ///< Optional error message location + ); + + /// @} + /// @name Implementation + /// @{ + protected: + /// @brief Construct an Archive for \p filename and optionally map it + /// into memory. + explicit Archive(const sys::Path& filename); + + /// @param data The symbol table data to be parsed + /// @param len The length of the symbol table data + /// @param error Set to address of a std::string to get error messages + /// @returns false on error + /// @brief Parse the symbol table at \p data. + bool parseSymbolTable(const void* data,unsigned len,std::string* error); + + /// @returns A fully populated ArchiveMember or 0 if an error occurred. + /// @brief Parse the header of a member starting at \p At + ArchiveMember* parseMemberHeader( + const char*&At, ///< The pointer to the location we're parsing + const char*End, ///< The pointer to the end of the archive + std::string* error ///< Optional error message catcher + ); + + /// @param ErrMessage Set to address of a std::string to get error messages + /// @returns false on error + /// @brief Check that the archive signature is correct + bool checkSignature(std::string* ErrMessage); + + /// @param ErrMessage Set to address of a std::string to get error messages + /// @returns false on error + /// @brief Load the entire archive. + bool loadArchive(std::string* ErrMessage); + + /// @param ErrMessage Set to address of a std::string to get error messages + /// @returns false on error + /// @brief Load just the symbol table. + bool loadSymbolTable(std::string* ErrMessage); + + /// @brief Write the symbol table to an ofstream. + void writeSymbolTable(std::ofstream& ARFile); + + /// Writes one ArchiveMember to an ofstream. If an error occurs, returns + /// false, otherwise true. If an error occurs and error is non-null then + /// it will be set to an error message. + /// @returns false Writing member succeeded + /// @returns true Writing member failed, \p error set to error message + bool writeMember( + const ArchiveMember& member, ///< The member to be written + std::ofstream& ARFile, ///< The file to write member onto + bool CreateSymbolTable, ///< Should symbol table be created? + bool TruncateNames, ///< Should names be truncated to 11 chars? + bool ShouldCompress, ///< Should the member be compressed? + std::string* ErrMessage ///< If non-null, place were error msg is set + ); + + /// @brief Fill in an ArchiveMemberHeader from ArchiveMember. + bool fillHeader(const ArchiveMember&mbr, + ArchiveMemberHeader& hdr,int sz, bool TruncateNames) const; + + /// @brief Maps archive into memory + bool mapToMemory(std::string* ErrMsg); + + /// @brief Frees all the members and unmaps the archive file. + void cleanUpMemory(); + + /// This type is used to keep track of bitcode modules loaded from the + /// symbol table. It maps the file offset to a pair that consists of the + /// associated ArchiveMember and the ModuleProvider. + /// @brief Module mapping type + typedef std::map<unsigned,std::pair<ModuleProvider*,ArchiveMember*> > + ModuleMap; + + + /// @} + /// @name Data + /// @{ + protected: + sys::Path archPath; ///< Path to the archive file we read/write + MembersList members; ///< The ilist of ArchiveMember + MemoryBuffer *mapfile; ///< Raw Archive contents mapped into memory + const char* base; ///< Base of the memory mapped file data + SymTabType symTab; ///< The symbol table + std::string strtab; ///< The string table for long file names + unsigned symTabSize; ///< Size in bytes of symbol table + unsigned firstFileOffset; ///< Offset to first normal file. + ModuleMap modules; ///< The modules loaded via symbol lookup. + ArchiveMember* foreignST; ///< This holds the foreign symbol table. + /// @} + /// @name Hidden + /// @{ + private: + Archive(); ///< Do not implement + Archive(const Archive&); ///< Do not implement + Archive& operator=(const Archive&); ///< Do not implement + /// @} +}; + +} // End llvm namespace + +#endif |
