X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FLinker%2FLinkArchives.cpp;h=fcaa7af3d5f001050974f65ab306997e4080090e;hb=2b0e300342cee213d3df41bf72d84316651805bb;hp=59570526e18507a1ec5e0b61136ff79c3d2c1de4;hpb=e676313966c3ede37644dbf2e49aa06f0c8b242a;p=oota-llvm.git diff --git a/lib/Linker/LinkArchives.cpp b/lib/Linker/LinkArchives.cpp index 59570526e18..fcaa7af3d5f 100644 --- a/lib/Linker/LinkArchives.cpp +++ b/lib/Linker/LinkArchives.cpp @@ -1,15 +1,14 @@ -//===- gccld.cpp - LLVM 'ld' compatible linker ----------------------------===// +//===- Linker.cpp - Link together LLVM objects and libraries --------------===// +// +// The LLVM Compiler Infrastructure // -// This utility is intended to be compatible with GCC, and follows standard -// system 'ld' conventions. As such, the default output file is ./a.out. -// Additionally, this program outputs a shell script that is used to invoke LLI -// to execute the program. In this manner, the generated executable (a.out for -// example), is directly executable, whereas the bytecode file actually lives in -// the a.out.bc file generated by this program. Also, Force is on by default. +// 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. +// +//===----------------------------------------------------------------------===// // -// Note that if someone (or a script) deletes the executable program generated, -// the .bc file will be left around. Considering that this is a temporary hack, -// I'm not too worried about this. +// This file contains routines to handle linking together LLVM bytecode files, +// and to handle annoying things like static libraries. // //===----------------------------------------------------------------------===// @@ -21,87 +20,30 @@ #include "llvm/Target/TargetData.h" #include "llvm/Transforms/IPO.h" #include "llvm/Transforms/Scalar.h" -#include "llvm/Transforms/Utils/Linker.h" +#include "llvm/Support/Linker.h" +#include "Config/config.h" #include "Support/CommandLine.h" #include "Support/FileUtilities.h" -#include "Support/Signals.h" +#include "llvm/System/Signals.h" #include "Support/SystemUtils.h" -#include "Config/stdlib.h" #include #include #include #include - -// -// Function: FileExists () -// -// Description: -// Determine if the specified filename exists and is readable. -// -// Inputs: -// FN - The name of the file. -// -// Outputs: -// None. -// -// Return Value: -// TRUE - The file exists and is readable. -// FALSE - The file does not exist or is unreadable. -// -static inline bool FileExists(const std::string &FN) { - return access(FN.c_str(), R_OK | F_OK) != -1; -} - -// -// Function: IsArchive () -// -// Description: -// Determine if the specified file is an ar archive. It determines this by -// checking the magic string at the beginning of the file. -// -// Inputs: -// filename - A C++ string containing the name of the file. -// -// Outputs: -// None. -// -// Return value: -// TRUE - The file is an archive. -// FALSE - The file is not an archive. -// -static inline bool IsArchive(const std::string &filename) -{ - std::string ArchiveMagic("!\012"); - char buf[1 + ArchiveMagic.size()]; - std::ifstream f(filename.c_str()); - f.read(buf, ArchiveMagic.size()); - buf[ArchiveMagic.size()] = '\0'; - return ArchiveMagic == buf; -} - -// -// Function: FindLib () -// -// Description: -// This function locates a particular library. It will prepend and append -// various directories, prefixes, and suffixes until it can find the library. -// -// Inputs: -// Filename - Name of the file to find. -// Paths - List of directories to search. -// -// Outputs: -// None. -// -// Return value: -// The name of the file is returned. -// If the file is not found, an empty string is returned. -// -static std::string -FindLib(const std::string &Filename, const std::vector &Paths) -{ +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.[suffix] 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 (FileExists(Filename)) + if (FileOpenable(Filename)) return Filename; // If that doesn't work, convert the name into a library name. @@ -112,13 +54,13 @@ FindLib(const std::string &Filename, const std::vector &Paths) for (unsigned Index = 0; Index != Paths.size(); ++Index) { std::string Directory = Paths[Index] + "/"; - if (FileExists(Directory + LibName + ".bc")) + if (!SharedObjectOnly && FileOpenable(Directory + LibName + ".bc")) return Directory + LibName + ".bc"; - if (FileExists(Directory + LibName + ".so")) - return Directory + LibName + ".so"; + if (FileOpenable(Directory + LibName + SHLIBEXT)) + return Directory + LibName + SHLIBEXT; - if (FileExists(Directory + LibName + ".a")) + if (!SharedObjectOnly && FileOpenable(Directory + LibName + ".a")) return Directory + LibName + ".a"; } @@ -128,31 +70,17 @@ FindLib(const std::string &Filename, const std::vector &Paths) return std::string(); LibName = std::string(SearchPath) + "/" + LibName; - if (FileExists(LibName)) + if (FileOpenable(LibName)) return LibName; return std::string(); } -// -// Function: GetAllDefinedSymbols () -// -// Description: -// Find all of the defined symbols in the specified module. -// -// Inputs: -// M - The module in which to find defined symbols. -// -// Outputs: -// DefinedSymbols - A set of C++ strings that will contain the name of all -// defined symbols. -// -// Return value: -// None. -// -void -GetAllDefinedSymbols(Module *M, std::set &DefinedSymbols) -{ +/// 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()); @@ -161,28 +89,21 @@ GetAllDefinedSymbols(Module *M, std::set &DefinedSymbols) DefinedSymbols.insert(I->getName()); } -// -// Function: GetAllUndefinedSymbols () -// -// Description: -// This 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 each other but -// aren't currently (thus we need to treat it as resolved). -// -// Inputs: -// M - The module in which to find undefined symbols. -// -// Outputs: -// UndefinedSymbols - A set of C++ strings containing the name of all -// undefined symbols. -// -// Return value: -// None. -// +/// 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 +/// each other but aren't currently (thus we need to treat it as resolved). +/// +/// Inputs: +/// M - The module in which to find undefined symbols. +/// +/// Outputs: +/// UndefinedSymbols - A set of C++ strings containing the name of all +/// undefined symbols. +/// void -GetAllUndefinedSymbols(Module *M, std::set &UndefinedSymbols) -{ +llvm::GetAllUndefinedSymbols(Module *M, + std::set &UndefinedSymbols) { std::set DefinedSymbols; UndefinedSymbols.clear(); // Start out empty @@ -211,61 +132,43 @@ GetAllUndefinedSymbols(Module *M, std::set &UndefinedSymbols) } -// -// Function: LoadObject () -// -// Description: -// Read the specified bytecode object file. -// -// Inputs: -// FN - The name of the file to load. -// -// Outputs: -// OutErrorMessage - The error message to give back to the caller. -// -// Return Value: -// A pointer to a module represening the bytecode file is returned. -// If an error occurs, the pointer is 0. -// -std::auto_ptr -LoadObject(const std::string & FN, std::string &OutErrorMessage) { - std::string ErrorMessage; - Module *Result = ParseBytecodeFile(FN, &ErrorMessage); +/// 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); - OutErrorMessage = "Bytecode file '" + FN + "' corrupt!"; - if (ErrorMessage.size()) OutErrorMessage += ": " + ErrorMessage; + ErrorMessage = "Bytecode file '" + FN + "' could not be loaded"; + if (ParserErrorMessage.size()) ErrorMessage += ": " + ParserErrorMessage; return std::auto_ptr(); } -// -// Function: LinkInArchive () -// -// Description: -// This function will open 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. -// +/// 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. // 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); if (UndefinedSymbols.empty()) { @@ -273,17 +176,13 @@ static bool LinkInArchive(Module *M, return false; // No need to link anything in! } - // // Load in the archive objects. - // - if (Verbose) std::cerr << " Loading '" << Filename << "'\n"; + 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) { @@ -302,15 +201,28 @@ static bool LinkInArchive(Module *M, const std::set &DefSymbols = DefinedSymbols[i]; bool ObjectRequired = false; - for (std::set::iterator I = UndefinedSymbols.begin(), - E = UndefinedSymbols.end(); I != E; ++I) - if (DefSymbols.count(*I)) { - if (Verbose) - std::cerr << " Found object providing symbol '" << *I << "'...\n"; - ObjectRequired = true; - break; - } - + + // + // 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)) @@ -334,25 +246,21 @@ static bool LinkInArchive(Module *M, return false; } -// -// Function: LinkInFile () -// -// Description: -// This function will open an archive library and link in all objects which -// provide symbols that are currently undefined. -// -// Inputs: -// HeadModule - 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. -// +/// 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, @@ -360,40 +268,33 @@ static bool LinkInFile(Module *HeadModule, { std::auto_ptr M(LoadObject(Filename, ErrorMessage)); if (M.get() == 0) return true; - if (Verbose) std::cerr << "Linking in '" << Filename << "'\n"; - return LinkModules(HeadModule, M.get(), &ErrorMessage); + bool Result = LinkModules(HeadModule, M.get(), &ErrorMessage); + if (Verbose) std::cerr << "Linked in bytecode file '" << Filename << "'\n"; + return Result; } -// -// Function: LinkFiles () -// -// Description: -// This function takes a module and a list of files and links them all -// together. It locates the file either in the current directory, as it's -// 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 LinkFiles(const char *progname, - Module *HeadModule, - const std::vector &Files, - bool Verbose) -{ +/// 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; @@ -403,19 +304,23 @@ bool LinkFiles(const char *progname, // Get the library search path from the environment char *SearchPath = getenv("LLVM_LIB_SEARCH_PATH"); - for (unsigned i = 1; i < Files.size(); ++i) { + for (unsigned i = 0; i < Files.size(); ++i) { // Determine where this file lives. - if (FileExists(Files[i])) { + if (FileOpenable(Files[i])) { Pathname = Files[i]; } else { if (SearchPath == NULL) { - std::cerr << "Cannot find " << Files[i]; + 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 (!FileExists(Pathname)) { - std::cerr << "Cannot find " << Files[i]; + if (!FileOpenable(Pathname)) { + std::cerr << progname << ": Cannot find linker input file '" + << Files[i] << "'\n"; return true; } } @@ -424,20 +329,20 @@ bool LinkFiles(const char *progname, // is not installed as a library. Detect that and link the library. if (IsArchive(Pathname)) { if (Verbose) - std::cerr << "Linking archive '" << Files[i] << "'\n"; + std::cerr << "Trying to link archive '" << Pathname << "'\n"; if (LinkInArchive(HeadModule, Pathname, ErrorMessage, Verbose)) { - PrintAndReturn(progname, ErrorMessage, - ": Error linking in '" + Files[i] + "'"); + std::cerr << progname << ": Error linking in archive '" << Pathname + << "': " << ErrorMessage << "\n"; return true; } - } else { + } else if (IsBytecode(Pathname)) { if (Verbose) - std::cerr << "Linking file '" << Files[i] << "'\n"; + std::cerr << "Trying to link bytecode file '" << Pathname << "'\n"; if (LinkInFile(HeadModule, Pathname, ErrorMessage, Verbose)) { - PrintAndReturn(progname, ErrorMessage, - ": error linking in '" + Files[i] + "'"); + std::cerr << progname << ": Error linking in bytecode file '" + << Pathname << "': " << ErrorMessage << "\n"; return true; } } @@ -446,39 +351,32 @@ bool LinkFiles(const char *progname, return false; } -// -// Function: LinkLibraries () -// -// Description: -// This function 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. -// -bool LinkLibraries(const char *progname, - Module *HeadModule, - const std::vector &Libraries, - const std::vector &LibPaths, - bool Verbose, - bool Native) -{ +/// 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 = 1; i < Libraries.size(); ++i) { + for (unsigned i = 0; i < Libraries.size(); ++i) { // Determine where this library lives. std::string Pathname = FindLib(Libraries[i], LibPaths); if (Pathname.empty()) { @@ -486,8 +384,9 @@ bool LinkLibraries(const char *progname, // we're doing a native link and give an error if we're doing a bytecode // link. if (!Native) { - PrintAndReturn(progname, "Cannot find " + Libraries[i]); - return true; + std::cerr << progname << ": WARNING: Cannot find library -l" + << Libraries[i] << "\n"; + continue; } } @@ -495,24 +394,26 @@ bool LinkLibraries(const char *progname, // is not installed as a library. Detect that and link the library. if (IsArchive(Pathname)) { if (Verbose) - std::cerr << "Linking archive '" << Libraries[i] << "'\n"; + std::cerr << "Trying to link archive '" << Pathname << "' (-l" + << Libraries[i] << ")\n"; if (LinkInArchive(HeadModule, Pathname, ErrorMessage, Verbose)) { - PrintAndReturn(progname, ErrorMessage, - ": Error linking in '" + Libraries[i] + "'"); - return true; + std::cerr << progname << ": " << ErrorMessage + << ": Error linking in archive '" << Pathname << "' (-l" + << Libraries[i] << ")\n"; + exit(1); } - } else { + } else if (IsBytecode(Pathname)) { if (Verbose) - std::cerr << "Linking file '" << Libraries[i] << "'\n"; + std::cerr << "Trying to link bytecode file '" << Pathname + << "' (-l" << Libraries[i] << ")\n"; if (LinkInFile(HeadModule, Pathname, ErrorMessage, Verbose)) { - PrintAndReturn(progname, ErrorMessage, - ": error linking in '" + Libraries[i] + "'"); - return true; + std::cerr << progname << ": " << ErrorMessage + << ": error linking in bytecode file '" << Pathname << "' (-l" + << Libraries[i] << ")\n"; + exit(1); } } } - - return false; }