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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 
operator ==(const Path & that) const33 bool Path::operator==(const Path &that) const {
34   return path == that.path;
35 }
36 
operator <(const Path & that) const37 bool Path::operator<(const Path& that) const {
38   return path < that.path;
39 }
40 
41 Path
GetLLVMConfigDir()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
IdentifyFileType(const char * magic,unsigned length)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
isArchive() const164 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
isDynamicLibrary() const172 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
isObjectFile() const187 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
FindLibrary(std::string & name)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 
GetDLLSuffix()211 StringRef Path::GetDLLSuffix() {
212   return &(LTDL_SHLIB_EXT[1]);
213 }
214 
215 void
appendSuffix(StringRef suffix)216 Path::appendSuffix(StringRef suffix) {
217   if (!suffix.empty()) {
218     path.append(".");
219     path.append(suffix);
220   }
221 }
222 
223 bool
isBitcodeFile() const224 Path::isBitcodeFile() const {
225   LLVMFileType type;
226   if (fs::identify_magic(str(), type))
227     return false;
228   return type == Bitcode_FileType;
229 }
230 
hasMagicNumber(StringRef Magic) const231 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 
getPathList(const char * path,std::vector<Path> & Paths)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 
getDirnameCharSep(StringRef path,const char * Sep)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
304