-//===- llvm/Transforms/Linker.h - Module Linker Interface --------*- C++ -*--=//
+//===- llvm/Linker.h - Module Linker Interface ------------------*- C++ -*-===//
//
-// This file defines the interface to the module linker.
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
+//
+// This file defines the interface to the module/file/archive linker.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LINKER_H
+#define LLVM_LINKER_H
-#ifndef LLVM_TRANSFORMATIONS_LINKER_H
-#define LLVM_TRANSFORMATIONS_LINKER_H
+#include <memory>
+#include <vector>
+#include "llvm/ADT/StringRef.h"
+
+namespace llvm {
+ namespace sys { class Path; }
-#include <string>
class Module;
+class LLVMContext;
+/// 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, bitcode files, or bitcode
+/// 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 stderr 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 {
-// LinkModules - This function links two modules together, with the resulting
-// left module modified to be the composite of the two input modules. If an
-// error occurs, true is returned and ErrorMsg (if not null) is set to indicate
-// the problem.
-//
-bool LinkModules(Module *Dest, const Module *Src, std::string *ErrorMsg = 0);
+ /// @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<std::pair<std::string,bool> > ItemList;
-#endif
+ /// This enumeration is used to control various optional features of the
+ /// linker.
+ enum ControlFlags {
+ Verbose = 1, ///< Print to stderr what steps the linker is taking
+ QuietWarnings = 2, ///< Don't print warnings to stderr.
+ QuietErrors = 4 ///< Don't print errors to stderr.
+ };
+
+ /// @}
+ /// @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(StringRef progname, ///< name of tool running linker
+ StringRef modulename, ///< name of linker's end-result module
+ LLVMContext &C, ///< Context for global info
+ unsigned Flags = 0 ///< ControlFlags (one or more |'d together)
+ );
+
+ /// 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(StringRef progname, Module* aModule, unsigned Flags = 0);
+
+ /// Destruct the Linker.
+ /// @brief Destructor
+ ~Linker();
+
+ /// @}
+ /// @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 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 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<sys::Path>& getLibPaths() const { return LibPaths; }
+
+ /// 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 stderr.
+ /// @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<std::string>& 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
+ ItemList& NativeItems ///< Output list of native files/libs
+ );
+
+ /// This function links the bitcode \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 bitcode 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<sys::Path> & Files ///< Files to link in
+ );
+
+ /// This function links a single bitcode file, \p File, into the composite
+ /// module. Note that this does not attempt to resolve symbols. This method
+ /// just loads the bitcode 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.
+ bool &is_native ///< Indicates if the file is native object file
+ );
+
+ /// 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<std::string> & 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 (
+ StringRef Library, ///< The library to link in
+ bool& is_native ///< Indicates if lib a native library
+ );
+
+ /// This function links one bitcode 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 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
+ bool& is_native ///< Indicates if archive is a native archive
+ );
+
+ /// 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
+ std::string* ErrorMsg = 0 /// Error/diagnostic string
+ ) {
+ return LinkModules(Composite, Src, ErrorMsg );
+ }
+
+ /// 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(StringRef Filename);
+
+ /// @}
+ /// @name Implementation
+ /// @{
+ private:
+ /// Read in and parse the bitcode file named by FN and return the
+ /// Module it contains (wrapped in an auto_ptr), or 0 if an error occurs.
+ std::auto_ptr<Module> LoadObject(const sys::Path& FN);
+
+ bool warning(StringRef message);
+ bool error(StringRef message);
+ void verbose(StringRef message);
+
+ /// @}
+ /// @name Data
+ /// @{
+ private:
+ LLVMContext& Context; ///< The context for global information
+ Module* Composite; ///< The composite module linked together
+ std::vector<sys::Path> 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
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