First version of the interface to Archive files. This introduces the

llvm::Archive class to provide for reading, writing, indexing and search
functions on standard ar(1) format files that contain bytecode modules.

Implementation to follow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17487 91177308-0d34-0410-b5e6-96231b3b80d8
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Reid Spencer 2004-11-05 09:19:17 +00:00
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//===-- llvm/Bytecode/Archive.h - LLVM Bytecode Archive ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header file defines the interface to LLVM Archive files. The interface
// is provided by the Archive class implemented by the lib/Bytecode/Archive
// library. This library is used to read and write archive (*.a) files that
// contain LLVM bytecode files (or others). It provides rudimentary capabilities
// to construct an archive file from a set of files, read the archive members
// into memory, search the archive for member files that fulfill unresolved
// symbols, and extract the archive back to the file system. 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
// library is optimized for reading.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_BYTECODE_ARCHIVER_H
#define LLVM_BYTECODE_ARCHIVER_H
#include "llvm/System/Path.h"
#include <map>
namespace llvm {
class ModuleProvider;
class Module;
/// This class represents an archive file. It abstracts away the file format,
/// and logical operations that can be done on an archive file. It also provides
/// utilities for controlling the runtime loading/reading of the archive file
/// to provide efficient access mechanisms for JIT systems and linkers.
class Archive {
/// @name Types
/// @{
public:
/// The user's interface to the archive symbol table. This multimap allows
/// symbols to be looked up and modules to be instantiated from the file
/// lazily via the ModuleProvider::materializeModule method.
typedef std::map<std::string,ModuleProvider*> SymTab;
/// This typedef is just shorthand for a vector of Path names
typedef std::vector<sys::Path> PathList;
/// This typedef is just shorthand for a vector of Modules
typedef std::vector<Module*> ModuleList;
/// This typedef is just shorthand for a vector of ModuleProvider
typedef std::vector<ModuleProvider*> ModuleProviderList;
/// This typedef is just shorthand for a vector of strings
typedef std::vector<std::string> StringList;
/// @}
/// @name Constructors
/// @{
public:
/// Create an empty archive file, \p Filename. The returned Archive object
/// will have no file members and an empty symbol table. The actual archive
/// file is not created until either the flush() method is called or the
/// returned Archive object is destructed.
/// @throws std::string if an error occurs
/// @returns An Archive* that represents the new archive file.
/// @brief Create an empty archive file.
static Archive* CreateEmpty(
const sys::Path& Filename ///< Name of archive file
);
/// Create a new archive file, \p Filename, from the LLVM modules \p Modules.
/// The module's externally visible linkage symbols will be added to the
/// archive's symbol table. The names of the file members will be obtained
/// from the Module::getModuleId() method. If that name is not unique, it will
/// be made unique by appending a monotonically increasng integer to it. If
/// \p StripName is non-empty, it specifies a prefix to be stripped from the
/// name of the file members. This allows archives with relative path names
/// to be created. The actual archive file is not created until either the
/// flush() method is called or the returned Archive object is destructed.
/// @returns An Archive* that that represents the newly created archive file.
/// @throws std::string if an error occurs
/// @brief Create an archive file from modules.
static Archive* CreateFromModules(
const sys::Path& Filename, ///< Name of archive file
const ModuleList& Modules, ///< Modules to be put in archive
const std::string& StripName="" ///< Prefix to strip from member names
);
/// Create a new archive file, \p Filename, from a set of existing \p Files.
/// Each entry in \p Files will be added to the archive. If any file is an
/// llvm bytecode file, its externally visible linkage symbols will be added
/// to the archive's symbol table. If any of the paths in \p Files refer to
/// directories, those directories will be ignored. Full path names to
/// files must be provided. However, if \p StripName is non-empty, it
/// specifies a prefix string to be removed from each path before it is
/// written as the name of the file member. Any path names that do not have
/// the \p StripName as a prefix will be saved with the full path name
/// provided in \p Files. This permits archives relative to a top level
/// directory to be created.
/// @throws std::string if an error occurs
/// @brief Create an archive file from files.
static Archive* CreateFromFiles(
const sys::Path& Filename, ///< Name of archive file
const PathList& Files, ///< File paths to be put in archive
const std::string& StripName="" ///< Prefix path name to strip from names
);
/// Open an existing archive file from \p Filename. The necessary
/// arrangements to read the file are made, but nothing much is actually
/// read from the file. Use the Accessor methods below to lazily obtain
/// those portions of the file that are of interest.
/// @throws std::string if an error occurs
/// @brief Open an existing archive.
static Archive* Open(
const sys::Path& Filename ///< Name of the archive file
);
/// This destructor "finalizes" the archive. Regardless of whether the
/// archive was created or opened, all memory associated with the archive
/// is released, including any SymTab* returned by the getSymbolTable()
/// method, any ModuleProviders and their associated Modules returned by
/// any interface method, etc. Additionally, if the archive was created
/// using one of the Create* methods, the archive is written to disk in
/// its final format. After this method exits, none of the memory
/// associated with the archive is valid. It is the user's responsibility
/// to ensure that all references to such memory is removed before the
/// Archive is destructed.
/// @throws std::string if an error occurs
/// @brief Destruct in-memory archive
~Archive();
/// @}
/// @name Accessors
/// @{
public:
/// 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 is constant and it may refer
/// to the same ModuleProvider object returned by this accessor in a
/// previous call (because the associated module defines both symbols). To
/// use the returned ModuleProvider* you must make a copy and call the
/// materializeModule method on the copy.
/// @throws std::string if an error occurs
/// @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.
const ModuleProvider* findModuleContainingSymbol(
const std::string& symbol ///< Symbol to be sought
) const;
/// Return the list of all the paths for the file members in the archive.
/// This is handy for generating the table of contents of the archive. Note
/// that the PathList object is cleared before it is populated. Any previous
/// contents will be lost.
/// @throw std::string if an error occurs
/// @returns nothing
/// @brief Get all the paths in the archive
void getAllPaths(
PathList& Paths ///< The list of paths returned
);
/// This method returns a caller readable SymTab object which is a std::map
/// of symbol names to ModuleProviders. Callers can traverse this symbol
/// table, look up specific symbols, etc. and materialize any Modules they
/// want with the associated ModuleProviders. It is unnecessary to call
/// this accessor more than once as the same object is alway returned, even
/// if changes have been made.
/// @returns a constant SymTab* that is the same for every invocation. The
/// caller should not attempt to free or modify this SymTab object, just use
/// it.
/// @brief Get the archive's symbol table.
const SymTab* getSymbolTable();
/// Extract the contents of the archive back to the file system using \p
/// RootDir as the directory at the root of the extraction. Each file
/// member is written back as a separate file. If \p flat is false, then
/// directories are created as necessary to restore the files to the correct
/// sub-directory of \p root as specified in the full path of the file
/// member. Otherwise, paths are ignored and all file members will be
/// extracted to the \p root directory using only the filename portion of
/// the path (directories ignored). If \p symtab is true, the archive's
/// symbol table will also be extracted to a file named __SYMTAB.
/// @returns nothing
/// @throws std::string if an error occurs
/// @brief Extract archive contents to a file.
void extractAllToDirectory(
const sys::Path& RootDir, ///< The root directory for extraction
bool Flat = true, ///< false = recreate directory structure
bool Symtab = false ///< true = extract symbol table too
);
/// Extract one file in the archive back to the file system using \p RootDir
/// as the directory at the root of the extraction. The file \p name is
/// extracted and placed into \p RootDir. If \p Flat is false, then any
/// intermediate directory names in the file member's path will also be
/// created. Otherwise, the member's file is created in RootDir ignoring
/// the leading path and using only the member's file name.
/// @throws std::string if an error occurs.
/// @returns nothing
/// @brief Extract a single archive file.
void extractOneFileToDirectory(
const sys::Path& RootDir, ///< The root directory for extraction
const sys::Path& name, ///< Name of file to extract
bool Flat = true ///< false = recreate directories
);
/// @}
/// @name Mutators
/// @{
public:
/// Each entry in \p Files will be added to the archive. If any file is an
/// llvm bytecode file, its externally visible linkage symbols will be added
/// to the archive's symbol table. If any of the paths in \p Files refer to
/// directories, those directories will be ignored. Full path names to
/// files must be provided. However, if \p StripName is non-empty, it
/// specifies a prefix string to be removed from each path before it is
/// written as the name of the file member. Any path names that do not have
/// the \p StripName as a prefix will be saved with the full path name
/// provided. This permits archives relative to a top level directory
/// to be created.
/// @throws std::string if an error occurs
/// @returns nothing
/// @brief Add a set of files to the archive.
void addFiles(
const PathList& Files, ///< The names of files to add to archive
const std::string& StripName="" ///< Prefix path to strip from names
);
/// Add a set of Modules to the archive. Names of member files will
/// be taken from the Module identifier (Module::getModuleIdentifier) if it
/// is unique. Non-unique member names will be made unique by appending a
/// number. The symbol table will be augmented with the global symbols of
/// all the modules provided. If \p StripName is non-empty, it
/// specifies a prefix string to be removed from each moduleId before it is
/// written as the name of the file member. Any path names that do not have
/// the \p StripName as a prefix will be saved with the full path name
/// provided. This permits archives relative to a top level directory to
/// be created.
/// @throws std::string if an error occurs
/// @returns nothing
/// @brief Add a set of modules to the archive.
void addModules(
const ModuleList& Modules, ///< The modules to add to the archive
const std::string& StripName="" ///< Prefix path to strip from names
);
/// @}
};
} // End llvm namespace
// vim: sw=2 ai
#endif