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