lib/Support/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/Support/Path.h"
  15 #include "llvm/Support/FileSystem.h"
  16 #include "llvm/Config/config.h"
  17 #include "llvm/Support/FileSystem.h"
  18 #include "llvm/Support/Endian.h"
  19 #include <cassert>
  20 #include <cstring>
  21 #include <ostream>
  22 using namespace llvm;
  23 using namespace sys;
  24 namespace {
  25 using support::ulittle32_t;
  26 }
  27
  28 //===----------------------------------------------------------------------===//
  29 //=== WARNING: Implementation here must contain only TRULY operating system
  30 //===          independent code.
  31 //===----------------------------------------------------------------------===//
  32
  33 bool Path::operator==(const Path &that) const {
  34   return path == that.path;
  35 }
  36
  37 bool Path::operator<(const Path& that) const {
  38   return path < that.path;
  39 }
  40
  41 Path
  42 Path::GetLLVMConfigDir() {
  43   Path result;
  44 #ifdef LLVM_ETCDIR
  45   if (result.set(LLVM_ETCDIR))
  46     return result;
  47 #endif
  48   return GetLLVMDefaultConfigDir();
  49 }
  50
  51 LLVMFileType
  52 sys::IdentifyFileType(const char *magic, unsigned length) {
  53   assert(magic && "Invalid magic number string");
  54   assert(length >=4 && "Invalid magic number length");
  55   switch ((unsigned char)magic[0]) {
  56     case 0xDE:  // 0x0B17C0DE = BC wraper
  57       if (magic[1] == (char)0xC0 && magic[2] == (char)0x17 &&
  58           magic[3] == (char)0x0B)
  59         return Bitcode_FileType;
  60       break;
  61     case 'B':
  62       if (magic[1] == 'C' && magic[2] == (char)0xC0 && magic[3] == (char)0xDE)
  63         return Bitcode_FileType;
  64       break;
  65     case '!':
  66       if (length >= 8)
  67         if (memcmp(magic,"!<arch>\n",8) == 0)
  68           return Archive_FileType;
  69       break;
  70
  71     case '\177':
  72       if (magic[1] == 'E' && magic[2] == 'L' && magic[3] == 'F') {
  73         if (length >= 18 && magic[17] == 0)
  74           switch (magic[16]) {
  75             default: break;
  76             case 1: return ELF_Relocatable_FileType;
  77             case 2: return ELF_Executable_FileType;
  78             case 3: return ELF_SharedObject_FileType;
  79             case 4: return ELF_Core_FileType;
  80           }
  81       }
  82       break;
  83
  84     case 0xCA:
  85       if (magic[1] == char(0xFE) && magic[2] == char(0xBA) &&
  86           magic[3] == char(0xBE)) {
  87         // This is complicated by an overlap with Java class files.
  88         // See the Mach-O section in /usr/share/file/magic for details.
  89         if (length >= 8 && magic[7] < 43)
  90           // FIXME: Universal Binary of any type.
  91           return Mach_O_DynamicallyLinkedSharedLib_FileType;
  92       }
  93       break;
  94
  95       // The two magic numbers for mach-o are:
  96       // 0xfeedface - 32-bit mach-o
  97       // 0xfeedfacf - 64-bit mach-o
  98     case 0xFE:
  99     case 0xCE:
 100     case 0xCF: {
 101       uint16_t type = 0;
 102       if (magic[0] == char(0xFE) && magic[1] == char(0xED) &&
 103           magic[2] == char(0xFA) &&
 104           (magic[3] == char(0xCE) || magic[3] == char(0xCF))) {
 105         /* Native endian */
 106         if (length >= 16) type = magic[14] << 8 | magic[15];
 107       } else if ((magic[0] == char(0xCE) || magic[0] == char(0xCF)) &&
 108                  magic[1] == char(0xFA) && magic[2] == char(0xED) &&
 109                  magic[3] == char(0xFE)) {
 110         /* Reverse endian */
 111         if (length >= 14) type = magic[13] << 8 | magic[12];
 112       }
 113       switch (type) {
 114         default: break;
 115         case 1: return Mach_O_Object_FileType;
 116         case 2: return Mach_O_Executable_FileType;
 117         case 3: return Mach_O_FixedVirtualMemorySharedLib_FileType;
 118         case 4: return Mach_O_Core_FileType;
 119         case 5: return Mach_O_PreloadExecutable_FileType;
 120         case 6: return Mach_O_DynamicallyLinkedSharedLib_FileType;
 121         case 7: return Mach_O_DynamicLinker_FileType;
 122         case 8: return Mach_O_Bundle_FileType;
 123         case 9: return Mach_O_DynamicallyLinkedSharedLibStub_FileType;
 124         case 10: break; // FIXME: MH_DSYM companion file with only debug.
 125       }
 126       break;
 127     }
 128     case 0xF0: // PowerPC Windows
 129     case 0x83: // Alpha 32-bit
 130     case 0x84: // Alpha 64-bit
 131     case 0x66: // MPS R4000 Windows
 132     case 0x50: // mc68K
 133     case 0x4c: // 80386 Windows
 134       if (magic[1] == 0x01)
 135         return COFF_FileType;
 136
 137     case 0x90: // PA-RISC Windows
 138     case 0x68: // mc68K Windows
 139       if (magic[1] == 0x02)
 140         return COFF_FileType;
 141       break;
 142
 143     case 0x4d: // Possible MS-DOS stub on Windows PE file
 144       if (magic[1] == 0x5a) {
 145         uint32_t off = *reinterpret_cast<const ulittle32_t *>(magic + 0x3c);
 146         // PE/COFF file, either EXE or DLL.
 147         if (off < length && memcmp(magic + off, "PE\0\0",4) == 0)
 148           return COFF_FileType;
 149       }
 150       break;
 151
 152     case 0x64: // x86-64 Windows.
 153       if (magic[1] == char(0x86))
 154         return COFF_FileType;
 155       break;
 156
 157     default:
 158       break;
 159   }
 160   return Unknown_FileType;
 161 }
 162
 163 bool
 164 Path::isArchive() const {
 165   LLVMFileType type;
 166   if (fs::identify_magic(str(), type))
 167     return false;
 168   return type == Archive_FileType;
 169 }
 170
 171 bool
 172 Path::isDynamicLibrary() const {
 173   LLVMFileType type;
 174   if (fs::identify_magic(str(), type))
 175     return false;
 176   switch (type) {
 177     default: return false;
 178     case Mach_O_FixedVirtualMemorySharedLib_FileType:
 179     case Mach_O_DynamicallyLinkedSharedLib_FileType:
 180     case Mach_O_DynamicallyLinkedSharedLibStub_FileType:
 181     case ELF_SharedObject_FileType:
 182     case COFF_FileType:  return true;
 183   }
 184 }
 185
 186 bool
 187 Path::isObjectFile() const {
 188   LLVMFileType type;
 189   if (fs::identify_magic(str(), type) || type == Unknown_FileType)
 190     return false;
 191   return true;
 192 }
 193
 194 Path
 195 Path::FindLibrary(std::string& name) {
 196   std::vector<sys::Path> LibPaths;
 197   GetSystemLibraryPaths(LibPaths);
 198   for (unsigned i = 0; i < LibPaths.size(); ++i) {
 199     sys::Path FullPath(LibPaths[i]);
 200     FullPath.appendComponent("lib" + name + LTDL_SHLIB_EXT);
 201     if (FullPath.isDynamicLibrary())
 202       return FullPath;
 203     FullPath.eraseSuffix();
 204     FullPath.appendSuffix("a");
 205     if (FullPath.isArchive())
 206       return FullPath;
 207   }
 208   return sys::Path();
 209 }
 210
 211 StringRef Path::GetDLLSuffix() {
 212   return &(LTDL_SHLIB_EXT[1]);
 213 }
 214
 215 void
 216 Path::appendSuffix(StringRef suffix) {
 217   if (!suffix.empty()) {
 218     path.append(".");
 219     path.append(suffix);
 220   }
 221 }
 222
 223 bool
 224 Path::isBitcodeFile() const {
 225   LLVMFileType type;
 226   if (fs::identify_magic(str(), type))
 227     return false;
 228   return type == Bitcode_FileType;
 229 }
 230
 231 bool Path::hasMagicNumber(StringRef Magic) const {
 232   std::string actualMagic;
 233   if (getMagicNumber(actualMagic, static_cast<unsigned>(Magic.size())))
 234     return Magic == actualMagic;
 235   return false;
 236 }
 237
 238 static void getPathList(const char*path, std::vector<Path>& Paths) {
 239   const char* at = path;
 240   const char* delim = strchr(at, PathSeparator);
 241   Path tmpPath;
 242   while (delim != 0) {
 243     std::string tmp(at, size_t(delim-at));
 244     if (tmpPath.set(tmp))
 245       if (tmpPath.canRead())
 246         Paths.push_back(tmpPath);
 247     at = delim + 1;
 248     delim = strchr(at, PathSeparator);
 249   }
 250
 251   if (*at != 0)
 252     if (tmpPath.set(std::string(at)))
 253       if (tmpPath.canRead())
 254         Paths.push_back(tmpPath);
 255 }
 256
 257 static StringRef getDirnameCharSep(StringRef path, const char *Sep) {
 258   assert(Sep[0] != '\0' && Sep[1] == '\0' &&
 259          "Sep must be a 1-character string literal.");
 260   if (path.empty())
 261     return ".";
 262
 263   // If the path is all slashes, return a single slash.
 264   // Otherwise, remove all trailing slashes.
 265
 266   signed pos = static_cast<signed>(path.size()) - 1;
 267
 268   while (pos >= 0 && path[pos] == Sep[0])
 269     --pos;
 270
 271   if (pos < 0)
 272     return path[0] == Sep[0] ? Sep : ".";
 273
 274   // Any slashes left?
 275   signed i = 0;
 276
 277   while (i < pos && path[i] != Sep[0])
 278     ++i;
 279
 280   if (i == pos) // No slashes?  Return "."
 281     return ".";
 282
 283   // There is at least one slash left.  Remove all trailing non-slashes.
 284   while (pos >= 0 && path[pos] != Sep[0])
 285     --pos;
 286
 287   // Remove any trailing slashes.
 288   while (pos >= 0 && path[pos] == Sep[0])
 289     --pos;
 290
 291   if (pos < 0)
 292     return path[0] == Sep[0] ? Sep : ".";
 293
 294   return path.substr(0, pos+1);
 295 }
 296
 297 // Include the truly platform-specific parts of this class.
 298 #if defined(LLVM_ON_UNIX)
 299 #include "Unix/Path.inc"
 300 #endif
 301 #if defined(LLVM_ON_WIN32)
 302 #include "Windows/Path.inc"
 303 #endif