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>
22using namespace llvm;
23using namespace sys;
24namespace {
25using support::ulittle32_t;
26}
27
28//===----------------------------------------------------------------------===//
29//=== WARNING: Implementation here must contain only TRULY operating system
30//===          independent code.
31//===----------------------------------------------------------------------===//
32
33bool Path::operator==(const Path &that) const {
34  return path == that.path;
35}
36
37bool Path::operator<(const Path& that) const {
38  return path < that.path;
39}
40
41LLVMFileType
42sys::IdentifyFileType(const char *magic, unsigned length) {
43  assert(magic && "Invalid magic number string");
44  assert(length >=4 && "Invalid magic number length");
45  switch ((unsigned char)magic[0]) {
46    case 0xDE:  // 0x0B17C0DE = BC wraper
47      if (magic[1] == (char)0xC0 && magic[2] == (char)0x17 &&
48          magic[3] == (char)0x0B)
49        return Bitcode_FileType;
50      break;
51    case 'B':
52      if (magic[1] == 'C' && magic[2] == (char)0xC0 && magic[3] == (char)0xDE)
53        return Bitcode_FileType;
54      break;
55    case '!':
56      if (length >= 8)
57        if (memcmp(magic,"!<arch>\n",8) == 0)
58          return Archive_FileType;
59      break;
60
61    case '\177':
62      if (magic[1] == 'E' && magic[2] == 'L' && magic[3] == 'F') {
63        bool Data2MSB = magic[5] == 2;
64        unsigned high = Data2MSB ? 16 : 17;
65        unsigned low  = Data2MSB ? 17 : 16;
66        if (length >= 18 && magic[high] == 0)
67          switch (magic[low]) {
68            default: break;
69            case 1: return ELF_Relocatable_FileType;
70            case 2: return ELF_Executable_FileType;
71            case 3: return ELF_SharedObject_FileType;
72            case 4: return ELF_Core_FileType;
73          }
74      }
75      break;
76
77    case 0xCA:
78      if (magic[1] == char(0xFE) && magic[2] == char(0xBA) &&
79          magic[3] == char(0xBE)) {
80        // This is complicated by an overlap with Java class files.
81        // See the Mach-O section in /usr/share/file/magic for details.
82        if (length >= 8 && magic[7] < 43)
83          // FIXME: Universal Binary of any type.
84          return Mach_O_DynamicallyLinkedSharedLib_FileType;
85      }
86      break;
87
88      // The two magic numbers for mach-o are:
89      // 0xfeedface - 32-bit mach-o
90      // 0xfeedfacf - 64-bit mach-o
91    case 0xFE:
92    case 0xCE:
93    case 0xCF: {
94      uint16_t type = 0;
95      if (magic[0] == char(0xFE) && magic[1] == char(0xED) &&
96          magic[2] == char(0xFA) &&
97          (magic[3] == char(0xCE) || magic[3] == char(0xCF))) {
98        /* Native endian */
99        if (length >= 16) type = magic[14] << 8 | magic[15];
100      } else if ((magic[0] == char(0xCE) || magic[0] == char(0xCF)) &&
101                 magic[1] == char(0xFA) && magic[2] == char(0xED) &&
102                 magic[3] == char(0xFE)) {
103        /* Reverse endian */
104        if (length >= 14) type = magic[13] << 8 | magic[12];
105      }
106      switch (type) {
107        default: break;
108        case 1: return Mach_O_Object_FileType;
109        case 2: return Mach_O_Executable_FileType;
110        case 3: return Mach_O_FixedVirtualMemorySharedLib_FileType;
111        case 4: return Mach_O_Core_FileType;
112        case 5: return Mach_O_PreloadExecutable_FileType;
113        case 6: return Mach_O_DynamicallyLinkedSharedLib_FileType;
114        case 7: return Mach_O_DynamicLinker_FileType;
115        case 8: return Mach_O_Bundle_FileType;
116        case 9: return Mach_O_DynamicallyLinkedSharedLibStub_FileType;
117        case 10: return Mach_O_DSYMCompanion_FileType;
118      }
119      break;
120    }
121    case 0xF0: // PowerPC Windows
122    case 0x83: // Alpha 32-bit
123    case 0x84: // Alpha 64-bit
124    case 0x66: // MPS R4000 Windows
125    case 0x50: // mc68K
126    case 0x4c: // 80386 Windows
127      if (magic[1] == 0x01)
128        return COFF_FileType;
129
130    case 0x90: // PA-RISC Windows
131    case 0x68: // mc68K Windows
132      if (magic[1] == 0x02)
133        return COFF_FileType;
134      break;
135
136    case 0x4d: // Possible MS-DOS stub on Windows PE file
137      if (magic[1] == 0x5a) {
138        uint32_t off = *reinterpret_cast<const ulittle32_t *>(magic + 0x3c);
139        // PE/COFF file, either EXE or DLL.
140        if (off < length && memcmp(magic + off, "PE\0\0",4) == 0)
141          return COFF_FileType;
142      }
143      break;
144
145    case 0x64: // x86-64 Windows.
146      if (magic[1] == char(0x86))
147        return COFF_FileType;
148      break;
149
150    default:
151      break;
152  }
153  return Unknown_FileType;
154}
155
156bool
157Path::isArchive() const {
158  fs::file_magic type;
159  if (fs::identify_magic(str(), type))
160    return false;
161  return type == fs::file_magic::archive;
162}
163
164bool
165Path::isDynamicLibrary() const {
166  fs::file_magic type;
167  if (fs::identify_magic(str(), type))
168    return false;
169  switch (type) {
170    default: return false;
171    case fs::file_magic::macho_fixed_virtual_memory_shared_lib:
172    case fs::file_magic::macho_dynamically_linked_shared_lib:
173    case fs::file_magic::macho_dynamically_linked_shared_lib_stub:
174    case fs::file_magic::elf_shared_object:
175    case fs::file_magic::pecoff_executable:  return true;
176  }
177}
178
179bool
180Path::isObjectFile() const {
181  fs::file_magic type;
182  if (fs::identify_magic(str(), type) || type == fs::file_magic::unknown)
183    return false;
184  return true;
185}
186
187Path
188Path::FindLibrary(std::string& name) {
189  std::vector<sys::Path> LibPaths;
190  GetSystemLibraryPaths(LibPaths);
191  for (unsigned i = 0; i < LibPaths.size(); ++i) {
192    sys::Path FullPath(LibPaths[i]);
193    FullPath.appendComponent("lib" + name + LTDL_SHLIB_EXT);
194    if (FullPath.isDynamicLibrary())
195      return FullPath;
196    FullPath.eraseSuffix();
197    FullPath.appendSuffix("a");
198    if (FullPath.isArchive())
199      return FullPath;
200  }
201  return sys::Path();
202}
203
204StringRef Path::GetDLLSuffix() {
205  return &(LTDL_SHLIB_EXT[1]);
206}
207
208void
209Path::appendSuffix(StringRef suffix) {
210  if (!suffix.empty()) {
211    path.append(".");
212    path.append(suffix);
213  }
214}
215
216bool
217Path::isBitcodeFile() const {
218  fs::file_magic type;
219  if (fs::identify_magic(str(), type))
220    return false;
221  return type == fs::file_magic::bitcode;
222}
223
224bool 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
231static 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
250static 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 "Windows/Path.inc"
296#endif
297