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
 131     default:
 132       break;
 133   }
 134   return Unknown_FileType;
 135 }
 136
 137 bool
 138 Path::isArchive() const {
 139   if (canRead())
 140     return hasMagicNumber("!<arch>\012");
 141   return false;
 142 }
 143
 144 bool
 145 Path::isDynamicLibrary() const {
 146   if (canRead()) {
 147     std::string Magic;
 148     if (getMagicNumber(Magic, 64))
 149       switch (IdentifyFileType(Magic.c_str(),
 150                                static_cast<unsigned>(Magic.length()))) {
 151         default: return false;
 152         case Mach_O_FixedVirtualMemorySharedLib_FileType:
 153         case Mach_O_DynamicallyLinkedSharedLib_FileType:
 154         case Mach_O_DynamicallyLinkedSharedLibStub_FileType:
 155         case ELF_SharedObject_FileType:
 156         case COFF_FileType:  return true;
 157       }
 158   }
 159   return false;
 160 }
 161
 162 Path
 163 Path::FindLibrary(std::string& name) {
 164   std::vector<sys::Path> LibPaths;
 165   GetSystemLibraryPaths(LibPaths);
 166   for (unsigned i = 0; i < LibPaths.size(); ++i) {
 167     sys::Path FullPath(LibPaths[i]);
 168     FullPath.appendComponent("lib" + name + LTDL_SHLIB_EXT);
 169     if (FullPath.isDynamicLibrary())
 170       return FullPath;
 171     FullPath.eraseSuffix();
 172     FullPath.appendSuffix("a");
 173     if (FullPath.isArchive())
 174       return FullPath;
 175   }
 176   return sys::Path();
 177 }
 178
 179 StringRef Path::GetDLLSuffix() {
 180   return LTDL_SHLIB_EXT;
 181 }
 182
 183 bool
 184 Path::isBitcodeFile() const {
 185   std::string actualMagic;
 186   if (!getMagicNumber(actualMagic, 4))
 187     return false;
 188   LLVMFileType FT =
 189     IdentifyFileType(actualMagic.c_str(),
 190                      static_cast<unsigned>(actualMagic.length()));
 191   return FT == Bitcode_FileType;
 192 }
 193
 194 bool Path::hasMagicNumber(StringRef Magic) const {
 195   std::string actualMagic;
 196   if (getMagicNumber(actualMagic, static_cast<unsigned>(Magic.size())))
 197     return Magic == actualMagic;
 198   return false;
 199 }
 200
 201 static void getPathList(const char*path, std::vector<Path>& Paths) {
 202   const char* at = path;
 203   const char* delim = strchr(at, PathSeparator);
 204   Path tmpPath;
 205   while (delim != 0) {
 206     std::string tmp(at, size_t(delim-at));
 207     if (tmpPath.set(tmp))
 208       if (tmpPath.canRead())
 209         Paths.push_back(tmpPath);
 210     at = delim + 1;
 211     delim = strchr(at, PathSeparator);
 212   }
 213
 214   if (*at != 0)
 215     if (tmpPath.set(std::string(at)))
 216       if (tmpPath.canRead())
 217         Paths.push_back(tmpPath);
 218 }
 219
 220 static StringRef getDirnameCharSep(StringRef path, const char *Sep) {
 221   assert(Sep[0] != '\0' && Sep[1] == '\0' &&
 222          "Sep must be a 1-character string literal.");
 223   if (path.empty())
 224     return ".";
 225
 226   // If the path is all slashes, return a single slash.
 227   // Otherwise, remove all trailing slashes.
 228
 229   signed pos = static_cast<signed>(path.size()) - 1;
 230
 231   while (pos >= 0 && path[pos] == Sep[0])
 232     --pos;
 233
 234   if (pos < 0)
 235     return path[0] == Sep[0] ? Sep : ".";
 236
 237   // Any slashes left?
 238   signed i = 0;
 239
 240   while (i < pos && path[i] != Sep[0])
 241     ++i;
 242
 243   if (i == pos) // No slashes?  Return "."
 244     return ".";
 245
 246   // There is at least one slash left.  Remove all trailing non-slashes.
 247   while (pos >= 0 && path[pos] != Sep[0])
 248     --pos;
 249
 250   // Remove any trailing slashes.
 251   while (pos >= 0 && path[pos] == Sep[0])
 252     --pos;
 253
 254   if (pos < 0)
 255     return path[0] == Sep[0] ? Sep : ".";
 256
 257   return path.substr(0, pos+1);
 258 }
 259
 260 // Include the truly platform-specific parts of this class.
 261 #if defined(LLVM_ON_UNIX)
 262 #include "Unix/Path.inc"
 263 #endif
 264 #if defined(LLVM_ON_WIN32)
 265 #include "Win32/Path.inc"
 266 #endif
 267