1 //===- llvm/unittest/Support/Path.cpp - Path tests ------------------------===//
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 #include "llvm/Support/Path.h"
11 #include "llvm/Support/ErrorHandling.h"
12 #include "llvm/Support/FileSystem.h"
13 #include "llvm/Support/MemoryBuffer.h"
14 #include "llvm/Support/raw_ostream.h"
15 #include "gtest/gtest.h"
16 
17 using namespace llvm;
18 using namespace llvm::sys;
19 
20 #define ASSERT_NO_ERROR(x) \
21   if (error_code ASSERT_NO_ERROR_ec = x) { \
22     SmallString<128> MessageStorage; \
23     raw_svector_ostream Message(MessageStorage); \
24     Message << #x ": did not return errc::success.\n" \
25             << "error number: " << ASSERT_NO_ERROR_ec.value() << "\n" \
26             << "error message: " << ASSERT_NO_ERROR_ec.message() << "\n"; \
27     GTEST_FATAL_FAILURE_(MessageStorage.c_str()); \
28   } else {}
29 
30 namespace {
31 
32 TEST(is_separator, Works) {
33   EXPECT_TRUE(path::is_separator('/'));
34   EXPECT_FALSE(path::is_separator('\0'));
35   EXPECT_FALSE(path::is_separator('-'));
36   EXPECT_FALSE(path::is_separator(' '));
37 
38 #ifdef LLVM_ON_WIN32
39   EXPECT_TRUE(path::is_separator('\\'));
40 #else
41   EXPECT_FALSE(path::is_separator('\\'));
42 #endif
43 }
44 
45 TEST(Support, Path) {
46   SmallVector<StringRef, 40> paths;
47   paths.push_back("");
48   paths.push_back(".");
49   paths.push_back("..");
50   paths.push_back("foo");
51   paths.push_back("/");
52   paths.push_back("/foo");
53   paths.push_back("foo/");
54   paths.push_back("/foo/");
55   paths.push_back("foo/bar");
56   paths.push_back("/foo/bar");
57   paths.push_back("//net");
58   paths.push_back("//net/foo");
59   paths.push_back("///foo///");
60   paths.push_back("///foo///bar");
61   paths.push_back("/.");
62   paths.push_back("./");
63   paths.push_back("/..");
64   paths.push_back("../");
65   paths.push_back("foo/.");
66   paths.push_back("foo/..");
67   paths.push_back("foo/./");
68   paths.push_back("foo/./bar");
69   paths.push_back("foo/..");
70   paths.push_back("foo/../");
71   paths.push_back("foo/../bar");
72   paths.push_back("c:");
73   paths.push_back("c:/");
74   paths.push_back("c:foo");
75   paths.push_back("c:/foo");
76   paths.push_back("c:foo/");
77   paths.push_back("c:/foo/");
78   paths.push_back("c:/foo/bar");
79   paths.push_back("prn:");
80   paths.push_back("c:\\");
81   paths.push_back("c:foo");
82   paths.push_back("c:\\foo");
83   paths.push_back("c:foo\\");
84   paths.push_back("c:\\foo\\");
85   paths.push_back("c:\\foo/");
86   paths.push_back("c:/foo\\bar");
87 
88   for (SmallVector<StringRef, 40>::const_iterator i = paths.begin(),
89                                                   e = paths.end();
90                                                   i != e;
91                                                   ++i) {
92     for (sys::path::const_iterator ci = sys::path::begin(*i),
93                                    ce = sys::path::end(*i);
94                                    ci != ce;
95                                    ++ci) {
96       ASSERT_FALSE(ci->empty());
97     }
98 
99 #if 0 // Valgrind is whining about this.
100     outs() << "    Reverse Iteration: [";
101     for (sys::path::reverse_iterator ci = sys::path::rbegin(*i),
102                                      ce = sys::path::rend(*i);
103                                      ci != ce;
104                                      ++ci) {
105       outs() << *ci << ',';
106     }
107     outs() << "]\n";
108 #endif
109 
110     path::has_root_path(*i);
111     path::root_path(*i);
112     path::has_root_name(*i);
113     path::root_name(*i);
114     path::has_root_directory(*i);
115     path::root_directory(*i);
116     path::has_parent_path(*i);
117     path::parent_path(*i);
118     path::has_filename(*i);
119     path::filename(*i);
120     path::has_stem(*i);
121     path::stem(*i);
122     path::has_extension(*i);
123     path::extension(*i);
124     path::is_absolute(*i);
125     path::is_relative(*i);
126 
127     SmallString<128> temp_store;
128     temp_store = *i;
129     ASSERT_NO_ERROR(fs::make_absolute(temp_store));
130     temp_store = *i;
131     path::remove_filename(temp_store);
132 
133     temp_store = *i;
134     path::replace_extension(temp_store, "ext");
135     StringRef filename(temp_store.begin(), temp_store.size()), stem, ext;
136     stem = path::stem(filename);
137     ext  = path::extension(filename);
138     EXPECT_EQ(*(--sys::path::end(filename)), (stem + ext).str());
139 
140     path::native(*i, temp_store);
141   }
142 }
143 
144 TEST(Support, RelativePathIterator) {
145   SmallString<64> Path(StringRef("c/d/e/foo.txt"));
146   typedef SmallVector<StringRef, 4> PathComponents;
147   PathComponents ExpectedPathComponents;
148   PathComponents ActualPathComponents;
149 
150   StringRef(Path).split(ExpectedPathComponents, "/");
151 
152   for (path::const_iterator I = path::begin(Path), E = path::end(Path); I != E;
153        ++I) {
154     ActualPathComponents.push_back(*I);
155   }
156 
157   ASSERT_EQ(ExpectedPathComponents.size(), ActualPathComponents.size());
158 
159   for (size_t i = 0; i <ExpectedPathComponents.size(); ++i) {
160     EXPECT_EQ(ExpectedPathComponents[i].str(), ActualPathComponents[i].str());
161   }
162 }
163 
164 TEST(Support, AbsolutePathIterator) {
165   SmallString<64> Path(StringRef("/c/d/e/foo.txt"));
166   typedef SmallVector<StringRef, 4> PathComponents;
167   PathComponents ExpectedPathComponents;
168   PathComponents ActualPathComponents;
169 
170   StringRef(Path).split(ExpectedPathComponents, "/");
171 
172   // The root path will also be a component when iterating
173   ExpectedPathComponents[0] = "/";
174 
175   for (path::const_iterator I = path::begin(Path), E = path::end(Path); I != E;
176        ++I) {
177     ActualPathComponents.push_back(*I);
178   }
179 
180   ASSERT_EQ(ExpectedPathComponents.size(), ActualPathComponents.size());
181 
182   for (size_t i = 0; i <ExpectedPathComponents.size(); ++i) {
183     EXPECT_EQ(ExpectedPathComponents[i].str(), ActualPathComponents[i].str());
184   }
185 }
186 
187 #ifdef LLVM_ON_WIN32
188 TEST(Support, AbsolutePathIteratorWin32) {
189   SmallString<64> Path(StringRef("c:\\c\\e\\foo.txt"));
190   typedef SmallVector<StringRef, 4> PathComponents;
191   PathComponents ExpectedPathComponents;
192   PathComponents ActualPathComponents;
193 
194   StringRef(Path).split(ExpectedPathComponents, "\\");
195 
196   // The root path (which comes after the drive name) will also be a component
197   // when iterating.
198   ExpectedPathComponents.insert(ExpectedPathComponents.begin()+1, "\\");
199 
200   for (path::const_iterator I = path::begin(Path), E = path::end(Path); I != E;
201        ++I) {
202     ActualPathComponents.push_back(*I);
203   }
204 
205   ASSERT_EQ(ExpectedPathComponents.size(), ActualPathComponents.size());
206 
207   for (size_t i = 0; i <ExpectedPathComponents.size(); ++i) {
208     EXPECT_EQ(ExpectedPathComponents[i].str(), ActualPathComponents[i].str());
209   }
210 }
211 #endif // LLVM_ON_WIN32
212 
213 TEST(Support, HomeDirectory) {
214 #ifdef LLVM_ON_UNIX
215   // This test only makes sense on Unix if $HOME is set.
216   if (::getenv("HOME")) {
217 #endif
218     SmallString<128> HomeDir;
219     EXPECT_TRUE(path::home_directory(HomeDir));
220     EXPECT_FALSE(HomeDir.empty());
221 #ifdef LLVM_ON_UNIX
222   }
223 #endif
224 }
225 
226 class FileSystemTest : public testing::Test {
227 protected:
228   /// Unique temporary directory in which all created filesystem entities must
229   /// be placed. It is recursively removed at the end of each test.
230   SmallString<128> TestDirectory;
231 
232   virtual void SetUp() {
233     ASSERT_NO_ERROR(
234         fs::createUniqueDirectory("file-system-test", TestDirectory));
235     // We don't care about this specific file.
236     errs() << "Test Directory: " << TestDirectory << '\n';
237     errs().flush();
238   }
239 
240   virtual void TearDown() {
241     ASSERT_NO_ERROR(fs::remove(TestDirectory.str()));
242   }
243 };
244 
245 TEST_F(FileSystemTest, Unique) {
246   // Create a temp file.
247   int FileDescriptor;
248   SmallString<64> TempPath;
249   ASSERT_NO_ERROR(
250       fs::createTemporaryFile("prefix", "temp", FileDescriptor, TempPath));
251 
252   // The same file should return an identical unique id.
253   fs::UniqueID F1, F2;
254   ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath), F1));
255   ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath), F2));
256   ASSERT_EQ(F1, F2);
257 
258   // Different files should return different unique ids.
259   int FileDescriptor2;
260   SmallString<64> TempPath2;
261   ASSERT_NO_ERROR(
262       fs::createTemporaryFile("prefix", "temp", FileDescriptor2, TempPath2));
263 
264   fs::UniqueID D;
265   ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath2), D));
266   ASSERT_NE(D, F1);
267   ::close(FileDescriptor2);
268 
269   ASSERT_NO_ERROR(fs::remove(Twine(TempPath2)));
270 
271   // Two paths representing the same file on disk should still provide the
272   // same unique id.  We can test this by making a hard link.
273   ASSERT_NO_ERROR(fs::create_hard_link(Twine(TempPath), Twine(TempPath2)));
274   fs::UniqueID D2;
275   ASSERT_NO_ERROR(fs::getUniqueID(Twine(TempPath2), D2));
276   ASSERT_EQ(D2, F1);
277 
278   ::close(FileDescriptor);
279 
280   SmallString<128> Dir1;
281   ASSERT_NO_ERROR(
282      fs::createUniqueDirectory("dir1", Dir1));
283   ASSERT_NO_ERROR(fs::getUniqueID(Dir1.c_str(), F1));
284   ASSERT_NO_ERROR(fs::getUniqueID(Dir1.c_str(), F2));
285   ASSERT_EQ(F1, F2);
286 
287   SmallString<128> Dir2;
288   ASSERT_NO_ERROR(
289      fs::createUniqueDirectory("dir2", Dir2));
290   ASSERT_NO_ERROR(fs::getUniqueID(Dir2.c_str(), F2));
291   ASSERT_NE(F1, F2);
292 }
293 
294 TEST_F(FileSystemTest, TempFiles) {
295   // Create a temp file.
296   int FileDescriptor;
297   SmallString<64> TempPath;
298   ASSERT_NO_ERROR(
299       fs::createTemporaryFile("prefix", "temp", FileDescriptor, TempPath));
300 
301   // Make sure it exists.
302   bool TempFileExists;
303   ASSERT_NO_ERROR(sys::fs::exists(Twine(TempPath), TempFileExists));
304   EXPECT_TRUE(TempFileExists);
305 
306   // Create another temp tile.
307   int FD2;
308   SmallString<64> TempPath2;
309   ASSERT_NO_ERROR(fs::createTemporaryFile("prefix", "temp", FD2, TempPath2));
310   ASSERT_TRUE(TempPath2.endswith(".temp"));
311   ASSERT_NE(TempPath.str(), TempPath2.str());
312 
313   fs::file_status A, B;
314   ASSERT_NO_ERROR(fs::status(Twine(TempPath), A));
315   ASSERT_NO_ERROR(fs::status(Twine(TempPath2), B));
316   EXPECT_FALSE(fs::equivalent(A, B));
317 
318   ::close(FD2);
319 
320   // Remove Temp2.
321   ASSERT_NO_ERROR(fs::remove(Twine(TempPath2), TempFileExists));
322   EXPECT_TRUE(TempFileExists);
323 
324   error_code EC = fs::status(TempPath2.c_str(), B);
325   EXPECT_EQ(EC, errc::no_such_file_or_directory);
326   EXPECT_EQ(B.type(), fs::file_type::file_not_found);
327 
328   // Make sure Temp2 doesn't exist.
329   ASSERT_NO_ERROR(fs::exists(Twine(TempPath2), TempFileExists));
330   EXPECT_FALSE(TempFileExists);
331 
332   SmallString<64> TempPath3;
333   ASSERT_NO_ERROR(fs::createTemporaryFile("prefix", "", TempPath3));
334   ASSERT_FALSE(TempPath3.endswith("."));
335 
336   // Create a hard link to Temp1.
337   ASSERT_NO_ERROR(fs::create_hard_link(Twine(TempPath), Twine(TempPath2)));
338   bool equal;
339   ASSERT_NO_ERROR(fs::equivalent(Twine(TempPath), Twine(TempPath2), equal));
340   EXPECT_TRUE(equal);
341   ASSERT_NO_ERROR(fs::status(Twine(TempPath), A));
342   ASSERT_NO_ERROR(fs::status(Twine(TempPath2), B));
343   EXPECT_TRUE(fs::equivalent(A, B));
344 
345   // Remove Temp1.
346   ::close(FileDescriptor);
347   ASSERT_NO_ERROR(fs::remove(Twine(TempPath), TempFileExists));
348   EXPECT_TRUE(TempFileExists);
349 
350   // Remove the hard link.
351   ASSERT_NO_ERROR(fs::remove(Twine(TempPath2), TempFileExists));
352   EXPECT_TRUE(TempFileExists);
353 
354   // Make sure Temp1 doesn't exist.
355   ASSERT_NO_ERROR(fs::exists(Twine(TempPath), TempFileExists));
356   EXPECT_FALSE(TempFileExists);
357 
358 #ifdef LLVM_ON_WIN32
359   // Path name > 260 chars should get an error.
360   const char *Path270 =
361     "abcdefghijklmnopqrstuvwxyz9abcdefghijklmnopqrstuvwxyz8"
362     "abcdefghijklmnopqrstuvwxyz7abcdefghijklmnopqrstuvwxyz6"
363     "abcdefghijklmnopqrstuvwxyz5abcdefghijklmnopqrstuvwxyz4"
364     "abcdefghijklmnopqrstuvwxyz3abcdefghijklmnopqrstuvwxyz2"
365     "abcdefghijklmnopqrstuvwxyz1abcdefghijklmnopqrstuvwxyz0";
366   EXPECT_EQ(fs::createUniqueFile(Twine(Path270), FileDescriptor, TempPath),
367             windows_error::path_not_found);
368 #endif
369 }
370 
371 TEST_F(FileSystemTest, DirectoryIteration) {
372   error_code ec;
373   for (fs::directory_iterator i(".", ec), e; i != e; i.increment(ec))
374     ASSERT_NO_ERROR(ec);
375 
376   // Create a known hierarchy to recurse over.
377   bool existed;
378   ASSERT_NO_ERROR(fs::create_directories(Twine(TestDirectory)
379                   + "/recursive/a0/aa1", existed));
380   ASSERT_NO_ERROR(fs::create_directories(Twine(TestDirectory)
381                   + "/recursive/a0/ab1", existed));
382   ASSERT_NO_ERROR(fs::create_directories(Twine(TestDirectory)
383                   + "/recursive/dontlookhere/da1", existed));
384   ASSERT_NO_ERROR(fs::create_directories(Twine(TestDirectory)
385                   + "/recursive/z0/za1", existed));
386   ASSERT_NO_ERROR(fs::create_directories(Twine(TestDirectory)
387                   + "/recursive/pop/p1", existed));
388   typedef std::vector<std::string> v_t;
389   v_t visited;
390   for (fs::recursive_directory_iterator i(Twine(TestDirectory)
391          + "/recursive", ec), e; i != e; i.increment(ec)){
392     ASSERT_NO_ERROR(ec);
393     if (path::filename(i->path()) == "p1") {
394       i.pop();
395       // FIXME: recursive_directory_iterator should be more robust.
396       if (i == e) break;
397     }
398     if (path::filename(i->path()) == "dontlookhere")
399       i.no_push();
400     visited.push_back(path::filename(i->path()));
401   }
402   v_t::const_iterator a0 = std::find(visited.begin(), visited.end(), "a0");
403   v_t::const_iterator aa1 = std::find(visited.begin(), visited.end(), "aa1");
404   v_t::const_iterator ab1 = std::find(visited.begin(), visited.end(), "ab1");
405   v_t::const_iterator dontlookhere = std::find(visited.begin(), visited.end(),
406                                                "dontlookhere");
407   v_t::const_iterator da1 = std::find(visited.begin(), visited.end(), "da1");
408   v_t::const_iterator z0 = std::find(visited.begin(), visited.end(), "z0");
409   v_t::const_iterator za1 = std::find(visited.begin(), visited.end(), "za1");
410   v_t::const_iterator pop = std::find(visited.begin(), visited.end(), "pop");
411   v_t::const_iterator p1 = std::find(visited.begin(), visited.end(), "p1");
412 
413   // Make sure that each path was visited correctly.
414   ASSERT_NE(a0, visited.end());
415   ASSERT_NE(aa1, visited.end());
416   ASSERT_NE(ab1, visited.end());
417   ASSERT_NE(dontlookhere, visited.end());
418   ASSERT_EQ(da1, visited.end()); // Not visited.
419   ASSERT_NE(z0, visited.end());
420   ASSERT_NE(za1, visited.end());
421   ASSERT_NE(pop, visited.end());
422   ASSERT_EQ(p1, visited.end()); // Not visited.
423 
424   // Make sure that parents were visited before children. No other ordering
425   // guarantees can be made across siblings.
426   ASSERT_LT(a0, aa1);
427   ASSERT_LT(a0, ab1);
428   ASSERT_LT(z0, za1);
429 
430   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/a0/aa1"));
431   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/a0/ab1"));
432   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/a0"));
433   ASSERT_NO_ERROR(
434       fs::remove(Twine(TestDirectory) + "/recursive/dontlookhere/da1"));
435   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/dontlookhere"));
436   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/pop/p1"));
437   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/pop"));
438   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/z0/za1"));
439   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive/z0"));
440   ASSERT_NO_ERROR(fs::remove(Twine(TestDirectory) + "/recursive"));
441 }
442 
443 const char archive[] = "!<arch>\x0A";
444 const char bitcode[] = "\xde\xc0\x17\x0b";
445 const char coff_object[] = "\x00\x00......";
446 const char coff_import_library[] = "\x00\x00\xff\xff....";
447 const char elf_relocatable[] = { 0x7f, 'E', 'L', 'F', 1, 2, 1, 0, 0,
448                                  0,    0,   0,   0,   0, 0, 0, 0, 1 };
449 const char macho_universal_binary[] = "\xca\xfe\xba\xbe...\0x00";
450 const char macho_object[] = "\xfe\xed\xfa\xce..........\x00\x01";
451 const char macho_executable[] = "\xfe\xed\xfa\xce..........\x00\x02";
452 const char macho_fixed_virtual_memory_shared_lib[] =
453     "\xfe\xed\xfa\xce..........\x00\x03";
454 const char macho_core[] = "\xfe\xed\xfa\xce..........\x00\x04";
455 const char macho_preload_executable[] = "\xfe\xed\xfa\xce..........\x00\x05";
456 const char macho_dynamically_linked_shared_lib[] =
457     "\xfe\xed\xfa\xce..........\x00\x06";
458 const char macho_dynamic_linker[] = "\xfe\xed\xfa\xce..........\x00\x07";
459 const char macho_bundle[] = "\xfe\xed\xfa\xce..........\x00\x08";
460 const char macho_dsym_companion[] = "\xfe\xed\xfa\xce..........\x00\x0a";
461 const char windows_resource[] = "\x00\x00\x00\x00\x020\x00\x00\x00\xff";
462 
463 TEST_F(FileSystemTest, Magic) {
464   struct type {
465     const char *filename;
466     const char *magic_str;
467     size_t magic_str_len;
468     fs::file_magic magic;
469   } types[] = {
470 #define DEFINE(magic)                                           \
471     { #magic, magic, sizeof(magic), fs::file_magic::magic }
472     DEFINE(archive),
473     DEFINE(bitcode),
474     DEFINE(coff_object),
475     DEFINE(coff_import_library),
476     DEFINE(elf_relocatable),
477     DEFINE(macho_universal_binary),
478     DEFINE(macho_object),
479     DEFINE(macho_executable),
480     DEFINE(macho_fixed_virtual_memory_shared_lib),
481     DEFINE(macho_core),
482     DEFINE(macho_preload_executable),
483     DEFINE(macho_dynamically_linked_shared_lib),
484     DEFINE(macho_dynamic_linker),
485     DEFINE(macho_bundle),
486     DEFINE(macho_dsym_companion),
487     DEFINE(windows_resource)
488 #undef DEFINE
489     };
490 
491   // Create some files filled with magic.
492   for (type *i = types, *e = types + (sizeof(types) / sizeof(type)); i != e;
493                                                                      ++i) {
494     SmallString<128> file_pathname(TestDirectory);
495     path::append(file_pathname, i->filename);
496     std::string ErrMsg;
497     raw_fd_ostream file(file_pathname.c_str(), ErrMsg, sys::fs::F_Binary);
498     ASSERT_FALSE(file.has_error());
499     StringRef magic(i->magic_str, i->magic_str_len);
500     file << magic;
501     file.close();
502     bool res = false;
503     ASSERT_NO_ERROR(fs::has_magic(file_pathname.c_str(), magic, res));
504     EXPECT_TRUE(res);
505     EXPECT_EQ(i->magic, fs::identify_magic(magic));
506     ASSERT_NO_ERROR(fs::remove(Twine(file_pathname)));
507   }
508 }
509 
510 #ifdef LLVM_ON_WIN32
511 TEST_F(FileSystemTest, CarriageReturn) {
512   SmallString<128> FilePathname(TestDirectory);
513   std::string ErrMsg;
514   path::append(FilePathname, "test");
515 
516   {
517     raw_fd_ostream File(FilePathname.c_str(), ErrMsg);
518     EXPECT_EQ(ErrMsg, "");
519     File << '\n';
520   }
521   {
522     OwningPtr<MemoryBuffer> Buf;
523     MemoryBuffer::getFile(FilePathname.c_str(), Buf);
524     EXPECT_EQ(Buf->getBuffer(), "\r\n");
525   }
526 
527   {
528     raw_fd_ostream File(FilePathname.c_str(), ErrMsg, sys::fs::F_Binary);
529     EXPECT_EQ(ErrMsg, "");
530     File << '\n';
531   }
532   {
533     OwningPtr<MemoryBuffer> Buf;
534     MemoryBuffer::getFile(FilePathname.c_str(), Buf);
535     EXPECT_EQ(Buf->getBuffer(), "\n");
536   }
537   ASSERT_NO_ERROR(fs::remove(Twine(FilePathname)));
538 }
539 #endif
540 
541 TEST_F(FileSystemTest, FileMapping) {
542   // Create a temp file.
543   int FileDescriptor;
544   SmallString<64> TempPath;
545   ASSERT_NO_ERROR(
546       fs::createTemporaryFile("prefix", "temp", FileDescriptor, TempPath));
547   // Map in temp file and add some content
548   error_code EC;
549   StringRef Val("hello there");
550   {
551     fs::mapped_file_region mfr(FileDescriptor,
552                                true,
553                                fs::mapped_file_region::readwrite,
554                                4096,
555                                0,
556                                EC);
557     ASSERT_NO_ERROR(EC);
558     std::copy(Val.begin(), Val.end(), mfr.data());
559     // Explicitly add a 0.
560     mfr.data()[Val.size()] = 0;
561     // Unmap temp file
562   }
563 
564   // Map it back in read-only
565   fs::mapped_file_region mfr(Twine(TempPath),
566                              fs::mapped_file_region::readonly,
567                              0,
568                              0,
569                              EC);
570   ASSERT_NO_ERROR(EC);
571 
572   // Verify content
573   EXPECT_EQ(StringRef(mfr.const_data()), Val);
574 
575   // Unmap temp file
576 
577 #if LLVM_HAS_RVALUE_REFERENCES
578   fs::mapped_file_region m(Twine(TempPath),
579                              fs::mapped_file_region::readonly,
580                              0,
581                              0,
582                              EC);
583   ASSERT_NO_ERROR(EC);
584   const char *Data = m.const_data();
585   fs::mapped_file_region mfrrv(llvm_move(m));
586   EXPECT_EQ(mfrrv.const_data(), Data);
587 #endif
588 }
589 } // anonymous namespace
590