LLVM API Documentation

Linker.cpp

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00001 //===- lib/Linker/Linker.cpp - Basic Linker functionality  ----------------===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by Reid Spencer and is distributed under the
00006 // University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file contains basic Linker functionality that all usages will need.
00011 //
00012 //===----------------------------------------------------------------------===//
00013 
00014 #include "llvm/Linker.h"
00015 #include "llvm/Module.h"
00016 #include "llvm/Bytecode/Reader.h"
00017 #include "llvm/Config/config.h"
00018 #include <iostream>
00019 
00020 using namespace llvm;
00021 
00022 Linker::Linker(const std::string& progname, const std::string& modname, unsigned flags)
00023   : Composite(0)
00024   , LibPaths()
00025   , Flags(flags)
00026   , Error()
00027   , ProgramName(progname)
00028 {
00029   Composite = new Module(modname);
00030 }
00031 
00032 Linker::Linker(const std::string& progname, Module* aModule, unsigned flags)
00033   : Composite(aModule)
00034   , LibPaths()
00035   , Flags(flags)
00036   , Error()
00037   , ProgramName(progname)
00038 {
00039 }
00040 
00041 Linker::~Linker() {
00042   delete Composite;
00043 }
00044 
00045 bool
00046 Linker::error(const std::string& message) {
00047   Error = message;
00048   if (!(Flags&QuietErrors)) {
00049     std::cerr << ProgramName << ": error: " << message << "\n";
00050   }
00051   return true;
00052 }
00053 
00054 bool
00055 Linker::warning(const std::string& message) {
00056   Error = message;
00057   if (!(Flags&QuietErrors)) {
00058     std::cerr << ProgramName << ": warning: " << message << "\n";
00059   }
00060   return false;
00061 }
00062 
00063 void
00064 Linker::verbose(const std::string& message) {
00065   if (Flags&Verbose) {
00066     std::cerr << "  " << message << "\n";
00067   }
00068 }
00069 
00070 void
00071 Linker::addPath(const sys::Path& path) {
00072   LibPaths.push_back(path);
00073 }
00074 
00075 void
00076 Linker::addPaths(const std::vector<std::string>& paths) {
00077   for (unsigned i = 0; i != paths.size(); ++i) {
00078     sys::Path aPath;
00079     aPath.set(paths[i]);
00080     LibPaths.push_back(aPath);
00081   }
00082 }
00083 
00084 void
00085 Linker::addSystemPaths() {
00086   sys::Path::GetBytecodeLibraryPaths(LibPaths);
00087   LibPaths.insert(LibPaths.begin(),sys::Path("./"));
00088 }
00089 
00090 Module*
00091 Linker::releaseModule() {
00092   Module* result = Composite;
00093   LibPaths.clear();
00094   Error.clear();
00095   Composite = 0;
00096   Flags = 0;
00097   return result;
00098 }
00099 
00100 // LoadObject - Read in and parse the bytecode file named by FN and return the
00101 // module it contains (wrapped in an auto_ptr), or auto_ptr<Module>() and set
00102 // Error if an error occurs.
00103 std::auto_ptr<Module>
00104 Linker::LoadObject(const sys::Path &FN) {
00105   std::string ParseErrorMessage;
00106   Module *Result = ParseBytecodeFile(FN.toString(), &ParseErrorMessage);
00107   if (Result)
00108     return std::auto_ptr<Module>(Result);
00109   Error = "Bytecode file '" + FN.toString() + "' could not be loaded";
00110   if (ParseErrorMessage.size())
00111     Error += ": " + ParseErrorMessage;
00112   return std::auto_ptr<Module>();
00113 }
00114 
00115 // IsLibrary - Determine if "Name" is a library in "Directory". Return
00116 // a non-empty sys::Path if its found, an empty one otherwise.
00117 static inline sys::Path IsLibrary(const std::string& Name,
00118                                   const sys::Path& Directory) {
00119 
00120   sys::Path FullPath(Directory);
00121 
00122   // Make sure the directory actually is a directory in the file system.
00123   if (FullPath.isDirectory())
00124   {
00125     // Try the libX.a form
00126     FullPath.appendComponent("lib" + Name);
00127     FullPath.appendSuffix("a");
00128     if (FullPath.isArchive())
00129       return FullPath;
00130 
00131     // Try the libX.bca form
00132     FullPath.eraseSuffix();
00133     FullPath.appendSuffix("bca");
00134     if (FullPath.isArchive())
00135       return FullPath;
00136 
00137     // Try the libX.so (or .dylib) form
00138     FullPath.eraseSuffix();
00139     FullPath.appendSuffix(&(LTDL_SHLIB_EXT[1]));
00140     if (FullPath.isDynamicLibrary())  // Native shared library?
00141       return FullPath;
00142     if (FullPath.isBytecodeFile())    // .so file containing bytecode?
00143       return FullPath;
00144 
00145     // Not found .. fall through
00146   }
00147 
00148   // Indicate that the library was not found in the directory.
00149   FullPath.clear();
00150   return FullPath;
00151 }
00152 
00153 /// FindLib - Try to convert Filename into the name of a file that we can open,
00154 /// if it does not already name a file we can open, by first trying to open
00155 /// Filename, then libFilename.[suffix] for each of a set of several common
00156 /// library suffixes, in each of the directories in LibPaths. Returns an empty
00157 /// Path if no matching file can be found.
00158 ///
00159 sys::Path
00160 Linker::FindLib(const std::string &Filename) {
00161   // Determine if the pathname can be found as it stands.
00162   sys::Path FilePath(Filename);
00163   if (FilePath.canRead() &&
00164       (FilePath.isArchive() || FilePath.isDynamicLibrary()))
00165     return FilePath;
00166 
00167   // Iterate over the directories in Paths to see if we can find the library
00168   // there.
00169   for (unsigned Index = 0; Index != LibPaths.size(); ++Index) {
00170     sys::Path Directory(LibPaths[Index]);
00171     sys::Path FullPath = IsLibrary(Filename,Directory);
00172     if (!FullPath.isEmpty())
00173       return FullPath;
00174   }
00175   return sys::Path();
00176 }