1 //===- llvm/unittest/Support/ReplaceFileTest.cpp - unit tests -------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/Support/Errc.h" 10 #include "llvm/Support/ErrorHandling.h" 11 #include "llvm/Support/FileSystem.h" 12 #include "llvm/Support/MemoryBuffer.h" 13 #include "llvm/Support/Path.h" 14 #include "llvm/Support/Process.h" 15 #include "gtest/gtest.h" 16 17 using namespace llvm; 18 using namespace llvm::sys; 19 20 #define ASSERT_NO_ERROR(x) \ 21 do { \ 22 if (std::error_code ASSERT_NO_ERROR_ec = x) { \ 23 errs() << #x ": did not return errc::success.\n" \ 24 << "error number: " << ASSERT_NO_ERROR_ec.value() << "\n" \ 25 << "error message: " << ASSERT_NO_ERROR_ec.message() << "\n"; \ 26 } \ 27 } while (false) 28 29 namespace { 30 std::error_code CreateFileWithContent(const SmallString<128> &FilePath, 31 const StringRef &content) { 32 int FD = 0; 33 if (std::error_code ec = fs::openFileForWrite(FilePath, FD)) 34 return ec; 35 36 const bool ShouldClose = true; 37 raw_fd_ostream OS(FD, ShouldClose); 38 OS << content; 39 40 return std::error_code(); 41 } 42 43 class ScopedFD { 44 int FD; 45 46 ScopedFD(const ScopedFD &) = delete; 47 ScopedFD &operator=(const ScopedFD &) = delete; 48 49 public: 50 explicit ScopedFD(int Descriptor) : FD(Descriptor) {} 51 ~ScopedFD() { Process::SafelyCloseFileDescriptor(FD); } 52 }; 53 54 bool FDHasContent(int FD, StringRef Content) { 55 auto Buffer = 56 MemoryBuffer::getOpenFile(sys::fs::convertFDToNativeFile(FD), "", -1); 57 assert(Buffer); 58 return Buffer.get()->getBuffer() == Content; 59 } 60 61 bool FileHasContent(StringRef File, StringRef Content) { 62 int FD = 0; 63 auto EC = fs::openFileForRead(File, FD); 64 (void)EC; 65 assert(!EC); 66 ScopedFD EventuallyCloseIt(FD); 67 return FDHasContent(FD, Content); 68 } 69 70 TEST(rename, FileOpenedForReadingCanBeReplaced) { 71 // Create unique temporary directory for this test. 72 SmallString<128> TestDirectory; 73 ASSERT_NO_ERROR(fs::createUniqueDirectory( 74 "FileOpenedForReadingCanBeReplaced-test", TestDirectory)); 75 76 // Add a couple of files to the test directory. 77 SmallString<128> SourceFileName(TestDirectory); 78 path::append(SourceFileName, "source"); 79 80 SmallString<128> TargetFileName(TestDirectory); 81 path::append(TargetFileName, "target"); 82 83 ASSERT_NO_ERROR(CreateFileWithContent(SourceFileName, "!!source!!")); 84 ASSERT_NO_ERROR(CreateFileWithContent(TargetFileName, "!!target!!")); 85 86 { 87 // Open the target file for reading. 88 int ReadFD = 0; 89 ASSERT_NO_ERROR(fs::openFileForRead(TargetFileName, ReadFD)); 90 ScopedFD EventuallyCloseIt(ReadFD); 91 92 // Confirm we can replace the file while it is open. 93 EXPECT_TRUE(!fs::rename(SourceFileName, TargetFileName)); 94 95 // We should still be able to read the old data through the existing 96 // descriptor. 97 EXPECT_TRUE(FDHasContent(ReadFD, "!!target!!")); 98 99 // The source file should no longer exist 100 EXPECT_FALSE(fs::exists(SourceFileName)); 101 } 102 103 // If we obtain a new descriptor for the target file, we should find that it 104 // contains the content that was in the source file. 105 EXPECT_TRUE(FileHasContent(TargetFileName, "!!source!!")); 106 107 // Rename the target file back to the source file name to confirm that rename 108 // still works if the destination does not already exist. 109 EXPECT_TRUE(!fs::rename(TargetFileName, SourceFileName)); 110 EXPECT_FALSE(fs::exists(TargetFileName)); 111 ASSERT_TRUE(fs::exists(SourceFileName)); 112 113 // Clean up. 114 ASSERT_NO_ERROR(fs::remove(SourceFileName)); 115 ASSERT_NO_ERROR(fs::remove(TestDirectory.str())); 116 } 117 118 TEST(rename, ExistingTemp) { 119 // Test that existing .tmpN files don't get deleted by the Windows 120 // sys::fs::rename implementation. 121 SmallString<128> TestDirectory; 122 ASSERT_NO_ERROR( 123 fs::createUniqueDirectory("ExistingTemp-test", TestDirectory)); 124 125 SmallString<128> SourceFileName(TestDirectory); 126 path::append(SourceFileName, "source"); 127 128 SmallString<128> TargetFileName(TestDirectory); 129 path::append(TargetFileName, "target"); 130 131 SmallString<128> TargetTmp0FileName(TestDirectory); 132 path::append(TargetTmp0FileName, "target.tmp0"); 133 134 SmallString<128> TargetTmp1FileName(TestDirectory); 135 path::append(TargetTmp1FileName, "target.tmp1"); 136 137 ASSERT_NO_ERROR(CreateFileWithContent(SourceFileName, "!!source!!")); 138 ASSERT_NO_ERROR(CreateFileWithContent(TargetFileName, "!!target!!")); 139 ASSERT_NO_ERROR(CreateFileWithContent(TargetTmp0FileName, "!!target.tmp0!!")); 140 141 { 142 // Use mapped_file_region to make sure that the destination file is mmap'ed. 143 // This will cause SetInformationByHandle to fail when renaming to the 144 // destination, and we will follow the code path that tries to give target 145 // a temporary name. 146 int TargetFD; 147 std::error_code EC; 148 ASSERT_NO_ERROR(fs::openFileForRead(TargetFileName, TargetFD)); 149 ScopedFD X(TargetFD); 150 sys::fs::mapped_file_region MFR(sys::fs::convertFDToNativeFile(TargetFD), 151 sys::fs::mapped_file_region::readonly, 10, 152 0, EC); 153 ASSERT_FALSE(EC); 154 155 ASSERT_NO_ERROR(fs::rename(SourceFileName, TargetFileName)); 156 157 #ifdef _WIN32 158 // Make sure that target was temporarily renamed to target.tmp1 on Windows. 159 // This is signified by a permission denied error as opposed to no such file 160 // or directory when trying to open it. 161 int Tmp1FD; 162 EXPECT_EQ(errc::permission_denied, 163 fs::openFileForRead(TargetTmp1FileName, Tmp1FD)); 164 #endif 165 } 166 167 EXPECT_TRUE(FileHasContent(TargetTmp0FileName, "!!target.tmp0!!")); 168 169 ASSERT_NO_ERROR(fs::remove(TargetFileName)); 170 ASSERT_NO_ERROR(fs::remove(TargetTmp0FileName)); 171 ASSERT_NO_ERROR(fs::remove(TestDirectory.str())); 172 } 173 174 } // anonymous namespace 175