From 5be572d3b4e08f3cbd05ed9339939b48d408570f Mon Sep 17 00:00:00 2001 From: Reid Spencer Date: Mon, 13 Dec 2004 02:58:05 +0000 Subject: [PATCH] Completely rewrite the interface to be class based llvm-svn: 18848 --- include/llvm/Linker.h | 348 ++++++++++++++++++++++++++++++------------ 1 file changed, 250 insertions(+), 98 deletions(-) diff --git a/include/llvm/Linker.h b/include/llvm/Linker.h index 5c6a2924e05..1b8e7516b44 100644 --- a/include/llvm/Linker.h +++ b/include/llvm/Linker.h @@ -14,120 +14,272 @@ #ifndef LLVM_LINKER_H #define LLVM_LINKER_H -#include "llvm/Support/CommandLine.h" -#include +#include "llvm/System/Path.h" #include -#include namespace llvm { class Module; -/// This type is used to pass the linkage items (libraries and files) to -/// the LinkItems function. It is composed of string/bool pairs. The string -/// provides the name of the file or library (as with the -l option). The bool -/// should be true for libraries, false for files, signifying "isLibrary". -/// @brief A list of string/bool pairs -typedef std::vector > LinkItemList; +/// This class provides the core functionality of linking in LLVM. It retains a +/// Module object which is the composite of the modules and libraries linked +/// into it. The composite Module can be retrieved via the getModule() method. +/// In this case the Linker still retains ownership of the Module. If the +/// releaseModule() method is used, the ownership of the Module is transferred +/// to the caller and the Linker object is only suitable for destruction. +/// The Linker can link Modules from memory, bytecode files, or bytecode +/// archives. It retains a set of search paths in which to find any libraries +/// presented to it. By default, the linker will generate error and warning +/// messages to std::cerr but this capability can be turned off with the +/// QuietWarnings and QuietErrors flags. It can also be instructed to verbosely +/// print out the linking actions it is taking with the Verbose flag. +/// @brief The LLVM Linker. +class Linker { -/// This function can be used to link a set of linkage items into a module. A -/// linkage item is one of the three things identified by the LinkItemKind -/// enumeration. This function allows linking to preserve the order of -/// specification associated with a command line, or for other purposes. Each -/// item will be linked in turn as it occurs in \p Items. Note that library -/// path items will only be in effect after they have been processed. -/// @returns The aggregated/linked Module. -/// @throws nothing -Module* LinkItems ( - const char * progname, ///< Name of the program being linked (for output) - const LinkItemList& Items, // Set of libraries/files to link in - const std::vector& LibPaths, // Paths to search for libraries - bool Verbose, ///< Link verbosely, indicating each action - bool Native ///< Linking is for a native executable -); + /// @name Types + /// @{ + public: + /// This type is used to pass the linkage items (libraries and files) to + /// the LinkItems function. It is composed of string/bool pairs. The string + /// provides the name of the file or library (as with the -l option). The + /// bool should be true for libraries and false for files, signifying + /// "isLibrary". + /// @brief A list of linkage items + typedef std::vector > ItemList; -/// This function provides some utility for tools that need to build the list -/// of link items from a triplet of command line options: Files, Libraries, and -/// LibraryPaths. The command line ordering is preserved by this function even -/// though the options are split into three separate cl::list. The -/// resulting \p OutList is suitable for use with LinkItems. -/// @see LinkItems -/// @throws nothing -void BuildLinkItems( - LinkItemList& OutList, - const cl::list& Files, ///< List of files to put in list - const cl::list& Libs ///< List of libraries to put in list -); + /// This enumeration is used to control various optional features of the + /// linker. + enum ControlFlags { + Verbose = 1, ///< Print to std::cerr what steps the linker is taking + QuietWarnings = 2, ///< Don't print errors and warnings to std::cerr. + QuietErrors = 4, ///< Indicate that this link is for a native executable + }; -/// This is the heart of the linker. The \p Src module is linked into the \p -/// Dest module. If an error occurs, true is returned, otherwise false. If \p -/// ErrorMsg is not null and an error occurs, \p *ErrorMsg will be set to a -/// readable string that indicates the nature of the error. Note that this can -/// destroy the Src module in arbitrary ways. -/// -/// @returns true if there's an error -/// @brief Link two modules together -bool LinkModules( - Module* Dest, ///< Module into which \p Src is linked - Module* Src, ///< Module linked into \p Dest - std::string* ErrorMsg ///< Optional error message string -); + /// @} + /// @name Constructors + /// @{ + public: + /// Construct the Linker with an empty module which will be given the + /// name \p progname. \p progname will also be used for error messages. + /// @brief Construct with empty module + Linker(const std::string& progname, unsigned Flags = 0 ); -/// This function links the bytecode \p Files into the \p HeadModule. Note that -/// this does not do any linking of unresolved symbols. The \p Files are all -/// completely linked into \p HeadModule regardless of unresolved symbols. This -/// function just loads each bytecode file and calls LinkModules on them. -/// @returns true if an error occurs, false otherwise -bool LinkFiles ( - const char * progname, ///< Name of the program being linked (for output) - Module * HeadModule, ///< Main (resulting) module to be linked into - const std::vector & Files, ///< Files to link in - bool Verbose ///< Link verbosely, indicating each action -); + /// Construct the Linker with a previously defined module, \p aModule. Use + /// \p progname for the name of the program in error messages. + /// @brief Construct with existing module + Linker(const std::string& progname, Module* aModule, unsigned Flags = 0); -/// This function links one archive, \p Filename, that contains bytecode into -/// \p HeadModule. If an error occurs, true is returned, otherwise false. If -/// \p ErrorMsg is not null and an error occurs, \p *ErrorMsg will be set to a -/// readable string that indicates the nature of the error. -/// @returns true if there's an error -/// @brief Link in one archive. -bool LinkInArchive( - Module* HeadModule, ///< Main (resulting) module to be linked into - const std::string& Filename, ///< Filename of the archive to link - std::string* ErrorMsg, ///< Error message if an error occurs. - bool Verbose ///< Link verbosely, indicating each action -); + /// Destruct the Linker. + /// @brief Destructor + ~Linker(); -/// This function provides the ability to handle the -L and -l options on a -/// linker's command line. It will link into \p HeadModule any modules found in -/// the \p Libraries (which might be found in the \p LibPaths). -/// @brief Link libraries into a module -void LinkLibraries ( - const char * progname, ///< Name of the program being linked (for output) - Module* HeadModule, ///< Main (resulting) module to be linked into - const std::vector & Libraries, ///< Set of libraries to link in - const std::vector & LibPaths, ///< Set of library paths - bool Verbose, ///< Link verbosely, indicating each action - bool Native ///< Linking is for a native executable -); + /// @} + /// @name Accessors + /// @{ + public: + /// This method gets the composite module into which linking is being + /// done. The Composite module starts out empty and accumulates modules + /// linked into it via the various LinkIn* methods. This method does not + /// release the Module to the caller. The Linker retains ownership and will + /// destruct the Module when the Linker is destructed. + /// @see releaseModule + /// @brief Get the linked/composite module. + Module* getModule() const { return Composite; } -/// This function looks at Module \p M and returns a set of strings, -/// \p DefinedSymbols, that is the publicly visible defined symbols in -/// module \p M. -void GetAllDefinedSymbols (Module *M, std::set &DefinedSymbols); + /// This method releases the composite Module into which linking is being + /// done. Ownership of the composite Module is transferred to the caller who + /// must arrange for its destruct. After this method is called, the Linker + /// terminates the linking session for the returned Module. It will no + /// longer utilize the returned Module but instead resets itself for + /// subsequent linking as if the constructor had been called. The Linker's + /// LibPaths and flags to be reset, and memory will be released. + /// @brief Release the linked/composite module. + Module* releaseModule(); -/// This function looks at Module \p M and returns a set of strings, -/// \p UnefinedSymbols, that is the publicly visible undefined symbols in -/// module \p M. -void GetAllUndefinedSymbols(Module *M, std::set &UndefinedSymbols); + /// This method gets the list of libraries that form the path that the + /// Linker will search when it is presented with a library name. + /// @brief Get the Linkers library path + const std::vector& getLibPaths() const { return LibPaths; } -/// This function looks through a set of \p Paths to find a library with the -/// name \p Filename. If \p SharedObjectOnly is true, it only finds a match -/// if the file is a shared library. -std::string FindLib(const std::string &Filename, - const std::vector &Paths, - bool SharedObjectOnly = false); + /// This method returns an error string suitable for printing to the user. + /// The return value will be empty unless an error occurred in one of the + /// LinkIn* methods. In those cases, the LinkIn* methods will have returned + /// true, indicating an error occurred. At most one error is retained so + /// this function always returns the last error that occurred. Note that if + /// the Quiet control flag is not set, the error string will have already + /// been printed to std::cerr. + /// @brief Get the text of the last error that occurred. + const std::string& getLastError() const { return Error; } + + /// @} + /// @name Mutators + /// @{ + public: + /// Add a path to the list of paths that the Linker will search. The Linker + /// accumulates the set of libraries added + /// library paths for the target platform. The standard libraries will + /// always be searched last. The added libraries will be searched in the + /// order added. + /// @brief Add a path. + void addPath(const sys::Path& path); + + /// Add a set of paths to the list of paths that the linker will search. The + /// Linker accumulates the set of libraries added. The \p paths will be + /// added to the end of the Linker's list. Order will be retained. + /// @brief Add a set of paths. + void addPaths(const std::vector& paths); + + /// This method augments the Linker's list of library paths with the system + /// paths of the host operating system, include LLVM_LIB_SEARCH_PATH. + /// @brief Add the system paths. + void addSystemPaths(); + + /// Control optional linker behavior by setting a group of flags. The flags + /// are defined in the ControlFlags enumeration. + /// @see ControlFlags + /// @brief Set control flags. + void setFlags(unsigned flags) { Flags = flags; } + + /// This method is the main interface to the linker. It can be used to + /// link a set of linkage items into a module. A linkage item is either a + /// file name with fully qualified path, or a library for which the Linker's + /// LibraryPath will be utilized to locate the library. The bool value in + /// the LinkItemKind should be set to true for libraries. This function + /// allows linking to preserve the order of specification associated with + /// the command line, or for other purposes. Each item will be linked in + /// turn as it occurs in \p Items. + /// @returns true if an error occurred, false otherwise + /// @see LinkItemKind + /// @see getLastError + /// @throws nothing + bool LinkInItems ( + const ItemList& Items // Set of libraries/files to link in + ); + + /// This function links the bytecode \p Files into the composite module. + /// Note that this does not do any linking of unresolved symbols. The \p + /// Files are all completely linked into \p HeadModule regardless of + /// unresolved symbols. This function just loads each bytecode file and + /// calls LinkInModule on them. + /// @returns true if an error occurs, false otherwise + /// @see getLastError + /// @brief Link in multiple files. + bool LinkInFiles ( + const std::vector & Files ///< Files to link in + ); + + /// This function links a single bytecode file, \p File, into the composite + /// module. Note that this does not attempt to resolve symbols. This method + /// just loads the bytecode file and calls LinkInModule on it. If an error + /// occurs, the Linker's error string is set. + /// @returns true if an error occurs, false otherwise + /// @see getLastError + /// @brief Link in a single file. + bool LinkInFile( + const sys::Path& File ///< File to link in. + ); + + /// This function provides a way to selectively link in a set of modules, + /// found in libraries, based on the unresolved symbols in the composite + /// module. Each item in \p Libraries should be the base name of a library, + /// as if given with the -l option of a linker tool. The Linker's LibPaths + /// are searched for the \p Libraries and any found will be linked in with + /// LinkInArchive. If an error occurs, the Linker's error string is set. + /// @see LinkInArchive + /// @see getLastError + /// @returns true if an error occurs, false otherwise + /// @brief Link libraries into the module + bool LinkInLibraries ( + const std::vector & Libraries ///< Libraries to link in + ); + + /// This function provides a way to selectively link in a set of modules, + /// found in one library, based on the unresolved symbols in the composite + /// module.The \p Library should be the base name of a library, as if given + /// with the -l option of a linker tool. The Linker's LibPaths are searched + /// for the \P Library and if found, it will be linked in with via the + /// LinkInArchive method. If an error occurs, the Linker's error string is + /// set. + /// @see LinkInArchive + /// @see getLastError + /// @returns true if an error occurs, false otherwise + /// @brief Link one library into the module + bool LinkInLibrary ( + const std::string& Library ///< The library to link in + ); + + /// This function links one bytecode archive, \p Filename, into the module. + /// The archive is searched to resolve outstanding symbols. Any modules in + /// the archive that resolve outstanding symbols will be linked in. The + /// library is searched repeatedly until no more modules that resolve + /// symbols can be found. If an error occurs, the error string is set. + /// To speed up this function, ensure the the archive has been processed + /// llvm-ranlib or the S option was given to llvm-ar when the archive was + /// created. These tools add a symbol table to the archive which makes the + /// search for undefined symbols much faster. + /// @see getLastError + /// @returns true if an error occurs, otherwise false. + /// @brief Link in one archive. + bool LinkInArchive( + const sys::Path& Filename ///< Filename of the archive to link + ); + + /// This method links the \p Src module into the Linker's Composite module + /// by calling LinkModules. All the other LinkIn* methods eventually + /// result in calling this method to link a Module into the Linker's + /// composite. + /// @see LinkModules + /// @returns True if an error occurs, false otherwise. + /// @brief Link in a module. + bool LinkInModule( + Module* Src ///< Module linked into \p Dest + ) { return LinkModules(Composite, Src, &Error); } + + /// This is the heart of the linker. This method will take unconditional + /// control of the \p Src module and link it into the \p Dest module. The + /// \p Src module will be destructed or subsumed by this method. In either + /// case it is not usable by the caller after this method is invoked. Only + /// the \p Dest module will remain. The \p Src module is linked into the + /// Linker's composite module such that types, global variables, functions, + /// and etc. are matched and resolved. If an error occurs, this function + /// returns true and ErrorMsg is set to a descriptive message about the + /// error. + /// @returns True if an error occurs, false otherwise. + /// @brief Generically link two modules together. + static bool LinkModules(Module* Dest, Module* Src, std::string* ErrorMsg); + + /// This function looks through the Linker's LibPaths to find a library with + /// the name \p Filename. If the library cannot be found, the returned path + /// will be empty (i.e. sys::Path::isEmpty() will return true). + /// @returns A sys::Path to the found library + /// @brief Find a library from its short name. + sys::Path FindLib(const std::string &Filename); + + /// @} + /// @name Implementation + /// @{ + private: + /// Read in and parse the bytecode file named by FN and return the + /// Module it contains (wrapped in an auto_ptr), or 0 if an error occurs. + std::auto_ptr LoadObject(const sys::Path& FN); + + bool warning(const std::string& message); + bool error(const std::string& message); + void verbose(const std::string& message); + + /// @} + /// @name Data + /// @{ + private: + Module* Composite; ///< The composite module linked together + std::vector LibPaths; ///< The library search paths + unsigned Flags; ///< Flags to control optional behavior. + std::string Error; ///< Text of error that occurred. + std::string ProgramName; ///< Name of the program being linked + /// @} +}; + } // End llvm namespace #endif