X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FLinker%2FLinkArchives.cpp;h=551cc8c390d86594de9813ec264ef9b488b5a5b7;hb=f45a82890e34984ad1e1e259f8fb902caddfb0b1;hp=296d87b0eb4979486cd4cbbb6157714e224773b2;hpb=7f7d16b62f9789c378a489a65ad51d50687c4c36;p=oota-llvm.git diff --git a/lib/Linker/LinkArchives.cpp b/lib/Linker/LinkArchives.cpp index 296d87b0eb4..551cc8c390d 100644 --- a/lib/Linker/LinkArchives.cpp +++ b/lib/Linker/LinkArchives.cpp @@ -1,93 +1,27 @@ -//===- Linker.cpp - Link together LLVM objects and libraries --------------===// -// +//===- lib/Linker/LinkArchives.cpp - Link LLVM objects and libraries ------===// +// // The LLVM Compiler Infrastructure // -// This file was developed by the LLVM research group and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. -// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// //===----------------------------------------------------------------------===// // -// This file contains routines to handle linking together LLVM bytecode files, +// This file contains routines to handle linking together LLVM bitcode files, // and to handle annoying things like static libraries. // //===----------------------------------------------------------------------===// -#include "gccld.h" +#include "llvm/Linker.h" #include "llvm/Module.h" -#include "llvm/PassManager.h" -#include "llvm/Bytecode/Reader.h" -#include "llvm/Bytecode/WriteBytecodePass.h" -#include "llvm/Target/TargetData.h" -#include "llvm/Transforms/IPO.h" -#include "llvm/Transforms/Scalar.h" -#include "llvm/Transforms/Utils/Linker.h" -#include "Support/CommandLine.h" -#include "Support/FileUtilities.h" -#include "Support/Signals.h" -#include "Support/SystemUtils.h" -#include -#include +#include "llvm/ModuleProvider.h" +#include "llvm/ADT/SetOperations.h" +#include "llvm/Bitcode/Archive.h" +#include "llvm/Config/config.h" #include #include using namespace llvm; -/// FindLib - Try to convert Filename into the name of a file that we can open, -/// if it does not already name a file we can open, by first trying to open -/// Filename, then libFilename. for each of a set of several common -/// library suffixes, in each of the directories in Paths and the directory -/// named by the value of the environment variable LLVM_LIB_SEARCH_PATH. Returns -/// an empty string if no matching file can be found. -/// -std::string llvm::FindLib(const std::string &Filename, - const std::vector &Paths, - bool SharedObjectOnly) { - // Determine if the pathname can be found as it stands. - if (FileOpenable(Filename)) - return Filename; - - // If that doesn't work, convert the name into a library name. - std::string LibName = "lib" + Filename; - - // Iterate over the directories in Paths to see if we can find the library - // there. - for (unsigned Index = 0; Index != Paths.size(); ++Index) { - std::string Directory = Paths[Index] + "/"; - - if (!SharedObjectOnly && FileOpenable(Directory + LibName + ".bc")) - return Directory + LibName + ".bc"; - - if (FileOpenable(Directory + LibName + SHLIBEXT)) - return Directory + LibName + SHLIBEXT; - - if (!SharedObjectOnly && FileOpenable(Directory + LibName + ".a")) - return Directory + LibName + ".a"; - } - - // One last hope: Check LLVM_LIB_SEARCH_PATH. - char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH"); - if (SearchPath == NULL) - return std::string(); - - LibName = std::string(SearchPath) + "/" + LibName; - if (FileOpenable(LibName)) - return LibName; - - return std::string(); -} - -/// GetAllDefinedSymbols - Modifies its parameter DefinedSymbols to contain the -/// name of each externally-visible symbol defined in M. -/// -void llvm::GetAllDefinedSymbols(Module *M, - std::set &DefinedSymbols) { - for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) - if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage()) - DefinedSymbols.insert(I->getName()); - for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I) - if (I->hasName() && !I->isExternal() && !I->hasInternalLinkage()) - DefinedSymbols.insert(I->getName()); -} - /// GetAllUndefinedSymbols - calculates the set of undefined symbols that still /// exist in an LLVM module. This is a bit tricky because there may be two /// symbols with the same name but different LLVM types that will be resolved to @@ -100,27 +34,46 @@ void llvm::GetAllDefinedSymbols(Module *M, /// UndefinedSymbols - A set of C++ strings containing the name of all /// undefined symbols. /// -void -llvm::GetAllUndefinedSymbols(Module *M, - std::set &UndefinedSymbols) { +static void +GetAllUndefinedSymbols(Module *M, std::set &UndefinedSymbols) { std::set DefinedSymbols; - UndefinedSymbols.clear(); // Start out empty - + UndefinedSymbols.clear(); + + // If the program doesn't define a main, try pulling one in from a .a file. + // This is needed for programs where the main function is defined in an + // archive, such f2c'd programs. + Function *Main = M->getFunction("main"); + if (Main == 0 || Main->isDeclaration()) + UndefinedSymbols.insert("main"); + for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) if (I->hasName()) { - if (I->isExternal()) + if (I->isDeclaration()) UndefinedSymbols.insert(I->getName()); - else if (!I->hasInternalLinkage()) + else if (!I->hasLocalLinkage()) { + assert(!I->hasDLLImportLinkage() + && "Found dllimported non-external symbol!"); DefinedSymbols.insert(I->getName()); + } } - for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I) + + for (Module::global_iterator I = M->global_begin(), E = M->global_end(); + I != E; ++I) if (I->hasName()) { - if (I->isExternal()) + if (I->isDeclaration()) UndefinedSymbols.insert(I->getName()); - else if (!I->hasInternalLinkage()) + else if (!I->hasLocalLinkage()) { + assert(!I->hasDLLImportLinkage() + && "Found dllimported non-external symbol!"); DefinedSymbols.insert(I->getName()); + } } - + + for (Module::alias_iterator I = M->alias_begin(), E = M->alias_end(); + I != E; ++I) + if (I->hasName()) + DefinedSymbols.insert(I->getName()); + // Prune out any defined symbols from the undefined symbols set... for (std::set::iterator I = UndefinedSymbols.begin(); I != UndefinedSymbols.end(); ) @@ -130,289 +83,119 @@ llvm::GetAllUndefinedSymbols(Module *M, ++I; // Keep this symbol in the undefined symbols list } - -/// LoadObject - Read in and parse the bytecode file named by FN and return the -/// module it contains (wrapped in an auto_ptr), or 0 and set ErrorMessage if an -/// error occurs. -/// -std::auto_ptr llvm::LoadObject(const std::string &FN, - std::string &ErrorMessage) { - std::string ParserErrorMessage; - Module *Result = ParseBytecodeFile(FN, &ParserErrorMessage); - if (Result) return std::auto_ptr(Result); - ErrorMessage = "Bytecode file '" + FN + "' could not be loaded"; - if (ParserErrorMessage.size()) ErrorMessage += ": " + ParserErrorMessage; - return std::auto_ptr(); -} - /// LinkInArchive - opens an archive library and link in all objects which /// provide symbols that are currently undefined. /// /// Inputs: -/// M - The module in which to link the archives. /// Filename - The pathname of the archive. -/// Verbose - Flags whether verbose messages should be printed. -/// -/// Outputs: -/// ErrorMessage - A C++ string detailing what error occurred, if any. /// /// Return Value: /// TRUE - An error occurred. /// FALSE - No errors. -/// -static bool LinkInArchive(Module *M, - const std::string &Filename, - std::string &ErrorMessage, - bool Verbose) -{ - // Find all of the symbols currently undefined in the bytecode program. +bool +Linker::LinkInArchive(const sys::Path &Filename, bool &is_native) { + // Make sure this is an archive file we're dealing with + if (!Filename.isArchive()) + return error("File '" + Filename.toString() + "' is not an archive."); + + // Open the archive file + verbose("Linking archive file '" + Filename.toString() + "'"); + + // Find all of the symbols currently undefined in the bitcode program. // If all the symbols are defined, the program is complete, and there is // no reason to link in any archive files. std::set UndefinedSymbols; - GetAllUndefinedSymbols(M, UndefinedSymbols); + GetAllUndefinedSymbols(Composite, UndefinedSymbols); + if (UndefinedSymbols.empty()) { - if (Verbose) std::cerr << " No symbols undefined, don't link library!\n"; + verbose("No symbols undefined, skipping library '" + + Filename.toString() + "'"); return false; // No need to link anything in! } - // Load in the archive objects. - if (Verbose) std::cerr << " Loading archive file '" << Filename << "'\n"; - std::vector Objects; - if (ReadArchiveFile(Filename, Objects, &ErrorMessage)) - return true; - - // Figure out which symbols are defined by all of the modules in the archive. - std::vector > DefinedSymbols; - DefinedSymbols.resize(Objects.size()); - for (unsigned i = 0; i != Objects.size(); ++i) { - GetAllDefinedSymbols(Objects[i], DefinedSymbols[i]); - } - - // While we are linking in object files, loop. - bool Linked = true; - while (Linked) { - Linked = false; + std::string ErrMsg; + std::auto_ptr AutoArch ( + Archive::OpenAndLoadSymbols(Filename,&ErrMsg)); - for (unsigned i = 0; i != Objects.size(); ++i) { - // Consider whether we need to link in this module... we only need to - // link it in if it defines some symbol which is so far undefined. - // - const std::set &DefSymbols = DefinedSymbols[i]; + Archive* arch = AutoArch.get(); - bool ObjectRequired = false; - - // - // If the object defines main() and the program currently has main() - // undefined, then automatically link in the module. Otherwise, look to - // see if it defines a symbol that is currently undefined. - // - if ((M->getMainFunction() == NULL) && - ((DefSymbols.find ("main")) != DefSymbols.end())) { - ObjectRequired = true; - } else { - for (std::set::iterator I = UndefinedSymbols.begin(), - E = UndefinedSymbols.end(); I != E; ++I) - if (DefSymbols.count(*I)) { - if (Verbose) - std::cerr << " Found object '" - << Objects[i]->getModuleIdentifier () - << "' providing symbol '" << *I << "'...\n"; - ObjectRequired = true; - break; - } - } - - // We DO need to link this object into the program... - if (ObjectRequired) { - if (LinkModules(M, Objects[i], &ErrorMessage)) - return true; // Couldn't link in the right object file... - - // Since we have linked in this object, delete it from the list of - // objects to consider in this archive file. - std::swap(Objects[i], Objects.back()); - std::swap(DefinedSymbols[i], DefinedSymbols.back()); - Objects.pop_back(); - DefinedSymbols.pop_back(); - --i; // Do not skip an entry - - // The undefined symbols set should have shrunk. - GetAllUndefinedSymbols(M, UndefinedSymbols); - Linked = true; // We have linked something in! - } - } + if (!arch) + return error("Cannot read archive '" + Filename.toString() + + "': " + ErrMsg); + if (!arch->isBitcodeArchive()) { + is_native = true; + return false; } - - return false; -} - -/// LinkInFile - opens a bytecode file and links in all objects which -/// provide symbols that are currently undefined. -/// -/// Inputs: -/// HeadModule - The module in which to link the bytecode file. -/// Filename - The pathname of the bytecode file. -/// Verbose - Flags whether verbose messages should be printed. -/// -/// Outputs: -/// ErrorMessage - A C++ string detailing what error occurred, if any. -/// -/// Return Value: -/// TRUE - An error occurred. -/// FALSE - No errors. -/// -static bool LinkInFile(Module *HeadModule, - const std::string &Filename, - std::string &ErrorMessage, - bool Verbose) -{ - std::auto_ptr M(LoadObject(Filename, ErrorMessage)); - if (M.get() == 0) return true; - bool Result = LinkModules(HeadModule, M.get(), &ErrorMessage); - if (Verbose) std::cerr << "Linked in bytecode file '" << Filename << "'\n"; - return Result; -} - -/// LinkFiles - takes a module and a list of files and links them all together. -/// It locates the file either in the current directory, as its absolute -/// or relative pathname, or as a file somewhere in LLVM_LIB_SEARCH_PATH. -/// -/// Inputs: -/// progname - The name of the program (infamous argv[0]). -/// HeadModule - The module under which all files will be linked. -/// Files - A vector of C++ strings indicating the LLVM bytecode filenames -/// to be linked. The names can refer to a mixture of pure LLVM -/// bytecode files and archive (ar) formatted files. -/// Verbose - Flags whether verbose output should be printed while linking. -/// -/// Outputs: -/// HeadModule - The module will have the specified LLVM bytecode files linked -/// in. -/// -/// Return value: -/// FALSE - No errors. -/// TRUE - Some error occurred. -/// -bool llvm::LinkFiles(const char *progname, Module *HeadModule, - const std::vector &Files, bool Verbose) { - // String in which to receive error messages. - std::string ErrorMessage; - - // Full pathname of the file - std::string Pathname; - - // Get the library search path from the environment - char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH"); - - for (unsigned i = 0; i < Files.size(); ++i) { - // Determine where this file lives. - if (FileOpenable(Files[i])) { - Pathname = Files[i]; - } else { - if (SearchPath == NULL) { - std::cerr << progname << ": Cannot find linker input file '" - << Files[i] << "'\n"; - std::cerr << progname - << ": Warning: Your LLVM_LIB_SEARCH_PATH is unset.\n"; - return true; - } - - Pathname = std::string(SearchPath)+"/"+Files[i]; - if (!FileOpenable(Pathname)) { - std::cerr << progname << ": Cannot find linker input file '" - << Files[i] << "'\n"; - return true; - } + is_native = false; + + // Save a set of symbols that are not defined by the archive. Since we're + // entering a loop, there's no point searching for these multiple times. This + // variable is used to "set_subtract" from the set of undefined symbols. + std::set NotDefinedByArchive; + + // Save the current set of undefined symbols, because we may have to make + // multiple passes over the archive: + std::set CurrentlyUndefinedSymbols; + + do { + CurrentlyUndefinedSymbols = UndefinedSymbols; + + // Find the modules we need to link into the target module + std::set Modules; + if (!arch->findModulesDefiningSymbols(UndefinedSymbols, Modules, &ErrMsg)) + return error("Cannot find symbols in '" + Filename.toString() + + "': " + ErrMsg); + + // If we didn't find any more modules to link this time, we are done + // searching this archive. + if (Modules.empty()) + break; + + // Any symbols remaining in UndefinedSymbols after + // findModulesDefiningSymbols are ones that the archive does not define. So + // we add them to the NotDefinedByArchive variable now. + NotDefinedByArchive.insert(UndefinedSymbols.begin(), + UndefinedSymbols.end()); + + // Loop over all the ModuleProviders that we got back from the archive + for (std::set::iterator I=Modules.begin(), E=Modules.end(); + I != E; ++I) { + + // Get the module we must link in. + std::string moduleErrorMsg; + std::auto_ptr AutoModule((*I)->releaseModule( &moduleErrorMsg )); + if (!moduleErrorMsg.empty()) + return error("Could not load a module: " + moduleErrorMsg); + + Module* aModule = AutoModule.get(); + + if (aModule != NULL) { + verbose(" Linking in module: " + aModule->getModuleIdentifier()); + + // Link it in + if (LinkInModule(aModule, &moduleErrorMsg)) { + return error("Cannot link in module '" + + aModule->getModuleIdentifier() + "': " + moduleErrorMsg); + } + } } - - // A user may specify an ar archive without -l, perhaps because it - // is not installed as a library. Detect that and link the library. - if (IsArchive(Pathname)) { - if (Verbose) - std::cerr << "Trying to link archive '" << Pathname << "'\n"; - - if (LinkInArchive(HeadModule, Pathname, ErrorMessage, Verbose)) { - PrintAndReturn(progname, ErrorMessage, - ": Error linking in archive '" + Pathname + "'"); - return true; - } - } else if (IsBytecode(Pathname)) { - if (Verbose) - std::cerr << "Trying to link bytecode file '" << Pathname << "'\n"; - - if (LinkInFile(HeadModule, Pathname, ErrorMessage, Verbose)) { - PrintAndReturn(progname, ErrorMessage, - ": Error linking in bytecode file '" + Pathname + "'"); - return true; - } - } - } + + // Get the undefined symbols from the aggregate module. This recomputes the + // symbols we still need after the new modules have been linked in. + GetAllUndefinedSymbols(Composite, UndefinedSymbols); + + // At this point we have two sets of undefined symbols: UndefinedSymbols + // which holds the undefined symbols from all the modules, and + // NotDefinedByArchive which holds symbols we know the archive doesn't + // define. There's no point searching for symbols that we won't find in the + // archive so we subtract these sets. + set_subtract(UndefinedSymbols, NotDefinedByArchive); + + // If there's no symbols left, no point in continuing to search the + // archive. + if (UndefinedSymbols.empty()) + break; + } while (CurrentlyUndefinedSymbols != UndefinedSymbols); return false; } - -/// LinkLibraries - takes the specified library files and links them into the -/// main bytecode object file. -/// -/// Inputs: -/// progname - The name of the program (infamous argv[0]). -/// HeadModule - The module into which all necessary libraries will be linked. -/// Libraries - The list of libraries to link into the module. -/// LibPaths - The list of library paths in which to find libraries. -/// Verbose - Flags whether verbose messages should be printed. -/// Native - Flags whether native code is being generated. -/// -/// Outputs: -/// HeadModule - The module will have all necessary libraries linked in. -/// -/// Return value: -/// FALSE - No error. -/// TRUE - Error. -/// -void llvm::LinkLibraries(const char *progname, Module *HeadModule, - const std::vector &Libraries, - const std::vector &LibPaths, - bool Verbose, bool Native) { - // String in which to receive error messages. - std::string ErrorMessage; - - for (unsigned i = 0; i < Libraries.size(); ++i) { - // Determine where this library lives. - std::string Pathname = FindLib(Libraries[i], LibPaths); - if (Pathname.empty()) { - // If the pathname does not exist, then continue to the next one if - // we're doing a native link and give an error if we're doing a bytecode - // link. - if (!Native) { - std::cerr << progname << ": WARNING: Cannot find library -l" - << Libraries[i] << "\n"; - continue; - } - } - - // A user may specify an ar archive without -l, perhaps because it - // is not installed as a library. Detect that and link the library. - if (IsArchive(Pathname)) { - if (Verbose) - std::cerr << "Trying to link archive '" << Pathname << "' (-l" - << Libraries[i] << ")\n"; - - if (LinkInArchive(HeadModule, Pathname, ErrorMessage, Verbose)) { - std::cerr << progname << ": " << ErrorMessage - << ": Error linking in archive '" << Pathname << "' (-l" - << Libraries[i] << ")\n"; - exit(1); - } - } else if (IsBytecode(Pathname)) { - if (Verbose) - std::cerr << "Trying to link bytecode file '" << Pathname - << "' (-l" << Libraries[i] << ")\n"; - - if (LinkInFile(HeadModule, Pathname, ErrorMessage, Verbose)) { - std::cerr << progname << ": " << ErrorMessage - << ": error linking in bytecode file '" << Pathname << "' (-l" - << Libraries[i] << ")\n"; - exit(1); - } - } - } -}