lib/System/Path.cpp

   1 //===-- Path.cpp - Implement OS Path Concept --------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 //  This header file implements the operating system Path concept.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/System/Path.h"
  15 #include "llvm/Config/config.h"
  16 #include <cassert>
  17 #include <cstring>
  18 #include <ostream>
  19 using namespace llvm;
  20 using namespace sys;
  21
  22 //===----------------------------------------------------------------------===//
  23 //=== WARNING: Implementation here must contain only TRULY operating system
  24 //===          independent code.
  25 //===----------------------------------------------------------------------===//
  26
  27 bool Path::operator==(const Path &that) const {
  28   return path == that.path;
  29 }
  30
  31 bool Path::operator<(const Path& that) const {
  32   return path < that.path;
  33 }
  34
  35 Path
  36 Path::GetLLVMConfigDir() {
  37   Path result;
  38 #ifdef LLVM_ETCDIR
  39   if (result.set(LLVM_ETCDIR))
  40     return result;
  41 #endif
  42   return GetLLVMDefaultConfigDir();
  43 }
  44
  45 LLVMFileType
  46 sys::IdentifyFileType(const char *magic, unsigned length) {
  47   assert(magic && "Invalid magic number string");
  48   assert(length >=4 && "Invalid magic number length");
  49   switch ((unsigned char)magic[0]) {
  50     case 0xDE:  // 0x0B17C0DE = BC wraper
  51       if (magic[1] == (char)0xC0 && magic[2] == (char)0x17 &&
  52           magic[3] == (char)0x0B)
  53         return Bitcode_FileType;
  54       break;
  55     case 'B':
  56       if (magic[1] == 'C' && magic[2] == (char)0xC0 && magic[3] == (char)0xDE)
  57         return Bitcode_FileType;
  58       break;
  59     case '!':
  60       if (length >= 8)
  61         if (memcmp(magic,"!<arch>\n",8) == 0)
  62           return Archive_FileType;
  63       break;
  64
  65     case '\177':
  66       if (magic[1] == 'E' && magic[2] == 'L' && magic[3] == 'F') {
  67         if (length >= 18 && magic[17] == 0)
  68           switch (magic[16]) {
  69             default: break;
  70             case 1: return ELF_Relocatable_FileType;
  71             case 2: return ELF_Executable_FileType;
  72             case 3: return ELF_SharedObject_FileType;
  73             case 4: return ELF_Core_FileType;
  74           }
  75       }
  76       break;
  77
  78     case 0xCA:
  79       if (magic[1] == char(0xFE) && magic[2] == char(0xBA) &&
  80           magic[3] == char(0xBE)) {
  81         // This is complicated by an overlap with Java class files.
  82         // See the Mach-O section in /usr/share/file/magic for details.
  83         if (length >= 8 && magic[7] < 43)
  84           // FIXME: Universal Binary of any type.
  85           return Mach_O_DynamicallyLinkedSharedLib_FileType;
  86       }
  87       break;
  88
  89     case 0xFE:
  90     case 0xCE: {
  91       uint16_t type = 0;
  92       if (magic[0] == char(0xFE) && magic[1] == char(0xED) &&
  93           magic[2] == char(0xFA) && magic[3] == char(0xCE)) {
  94         /* Native endian */
  95         if (length >= 16) type = magic[14] << 8 | magic[15];
  96       } else if (magic[0] == char(0xCE) && magic[1] == char(0xFA) &&
  97                  magic[2] == char(0xED) && magic[3] == char(0xFE)) {
  98         /* Reverse endian */
  99         if (length >= 14) type = magic[13] << 8 | magic[12];
 100       }
 101       switch (type) {
 102         default: break;
 103         case 1: return Mach_O_Object_FileType;
 104         case 2: return Mach_O_Executable_FileType;
 105         case 3: return Mach_O_FixedVirtualMemorySharedLib_FileType;
 106         case 4: return Mach_O_Core_FileType;
 107         case 5: return Mach_O_PreloadExectuable_FileType;
 108         case 6: return Mach_O_DynamicallyLinkedSharedLib_FileType;
 109         case 7: return Mach_O_DynamicLinker_FileType;
 110         case 8: return Mach_O_Bundle_FileType;
 111         case 9: return Mach_O_DynamicallyLinkedSharedLibStub_FileType;
 112         case 10: break; // FIXME: MH_DSYM companion file with only debug.
 113       }
 114       break;
 115     }
 116     case 0xF0: // PowerPC Windows
 117     case 0x83: // Alpha 32-bit
 118     case 0x84: // Alpha 64-bit
 119     case 0x66: // MPS R4000 Windows
 120     case 0x50: // mc68K
 121     case 0x4c: // 80386 Windows
 122       if (magic[1] == 0x01)
 123         return COFF_FileType;
 124
 125     case 0x90: // PA-RISC Windows
 126     case 0x68: // mc68K Windows
 127       if (magic[1] == 0x02)
 128         return COFF_FileType;
 129       break;
 130     case 0x64: // x86-64 Windows.
 131       if (magic[1] == char(0x86))
 132         return COFF_FileType;
 133       break;
 134
 135     default:
 136       break;
 137   }
 138   return Unknown_FileType;
 139 }
 140
 141 bool
 142 Path::isArchive() const {
 143   return hasMagicNumber("!<arch>\012");
 144 }
 145
 146 bool
 147 Path::isDynamicLibrary() const {
 148   std::string Magic;
 149   if (getMagicNumber(Magic, 64))
 150     switch (IdentifyFileType(Magic.c_str(),
 151                              static_cast<unsigned>(Magic.length()))) {
 152       default: return false;
 153       case Mach_O_FixedVirtualMemorySharedLib_FileType:
 154       case Mach_O_DynamicallyLinkedSharedLib_FileType:
 155       case Mach_O_DynamicallyLinkedSharedLibStub_FileType:
 156       case ELF_SharedObject_FileType:
 157       case COFF_FileType:  return true;
 158     }
 159
 160   return false;
 161 }
 162
 163 bool
 164 Path::isObjectFile() const {
 165   std::string Magic;
 166   if (getMagicNumber(Magic, 64))
 167     if (IdentifyFileType(Magic.c_str(),
 168                          static_cast<unsigned>(Magic.length()))
 169         != Unknown_FileType) {
 170       // Everything in LLVMFileType is currently an object file.
 171       return true;
 172     }
 173
 174   return false;
 175 }
 176
 177 Path
 178 Path::FindLibrary(std::string& name) {
 179   std::vector<sys::Path> LibPaths;
 180   GetSystemLibraryPaths(LibPaths);
 181   for (unsigned i = 0; i < LibPaths.size(); ++i) {
 182     sys::Path FullPath(LibPaths[i]);
 183     FullPath.appendComponent("lib" + name + LTDL_SHLIB_EXT);
 184     if (FullPath.isDynamicLibrary())
 185       return FullPath;
 186     FullPath.eraseSuffix();
 187     FullPath.appendSuffix("a");
 188     if (FullPath.isArchive())
 189       return FullPath;
 190   }
 191   return sys::Path();
 192 }
 193
 194 StringRef Path::GetDLLSuffix() {
 195   return &(LTDL_SHLIB_EXT[1]);
 196 }
 197
 198 bool
 199 Path::appendSuffix(StringRef suffix) {
 200   if (!suffix.empty()) {
 201     std::string save(path);
 202     path.append(".");
 203     path.append(suffix);
 204     if (!isValid()) {
 205       path = save;
 206       return false;
 207     }
 208   }
 209
 210   return true;
 211 }
 212
 213 bool
 214 Path::isBitcodeFile() const {
 215   std::string actualMagic;
 216   if (!getMagicNumber(actualMagic, 4))
 217     return false;
 218   LLVMFileType FT =
 219     IdentifyFileType(actualMagic.c_str(),
 220                      static_cast<unsigned>(actualMagic.length()));
 221   return FT == Bitcode_FileType;
 222 }
 223
 224 bool Path::hasMagicNumber(StringRef Magic) const {
 225   std::string actualMagic;
 226   if (getMagicNumber(actualMagic, static_cast<unsigned>(Magic.size())))
 227     return Magic == actualMagic;
 228   return false;
 229 }
 230
 231 static void getPathList(const char*path, std::vector<Path>& Paths) {
 232   const char* at = path;
 233   const char* delim = strchr(at, PathSeparator);
 234   Path tmpPath;
 235   while (delim != 0) {
 236     std::string tmp(at, size_t(delim-at));
 237     if (tmpPath.set(tmp))
 238       if (tmpPath.canRead())
 239         Paths.push_back(tmpPath);
 240     at = delim + 1;
 241     delim = strchr(at, PathSeparator);
 242   }
 243
 244   if (*at != 0)
 245     if (tmpPath.set(std::string(at)))
 246       if (tmpPath.canRead())
 247         Paths.push_back(tmpPath);
 248 }
 249
 250 static StringRef getDirnameCharSep(StringRef path, const char *Sep) {
 251   assert(Sep[0] != '\0' && Sep[1] == '\0' &&
 252          "Sep must be a 1-character string literal.");
 253   if (path.empty())
 254     return ".";
 255
 256   // If the path is all slashes, return a single slash.
 257   // Otherwise, remove all trailing slashes.
 258
 259   signed pos = static_cast<signed>(path.size()) - 1;
 260
 261   while (pos >= 0 && path[pos] == Sep[0])
 262     --pos;
 263
 264   if (pos < 0)
 265     return path[0] == Sep[0] ? Sep : ".";
 266
 267   // Any slashes left?
 268   signed i = 0;
 269
 270   while (i < pos && path[i] != Sep[0])
 271     ++i;
 272
 273   if (i == pos) // No slashes?  Return "."
 274     return ".";
 275
 276   // There is at least one slash left.  Remove all trailing non-slashes.
 277   while (pos >= 0 && path[pos] != Sep[0])
 278     --pos;
 279
 280   // Remove any trailing slashes.
 281   while (pos >= 0 && path[pos] == Sep[0])
 282     --pos;
 283
 284   if (pos < 0)
 285     return path[0] == Sep[0] ? Sep : ".";
 286
 287   return path.substr(0, pos+1);
 288 }
 289
 290 // Include the truly platform-specific parts of this class.
 291 #if defined(LLVM_ON_UNIX)
 292 #include "Unix/Path.inc"
 293 #endif
 294 #if defined(LLVM_ON_WIN32)
 295 #include "Win32/Path.inc"
 296 #endif
 297