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 = MemoryBuffer::getOpenFile(FD, "", -1); 56 assert(Buffer); 57 return Buffer.get()->getBuffer() == Content; 58 } 59 60 bool FileHasContent(StringRef File, StringRef Content) { 61 int FD = 0; 62 auto EC = fs::openFileForRead(File, FD); 63 (void)EC; 64 assert(!EC); 65 ScopedFD EventuallyCloseIt(FD); 66 return FDHasContent(FD, Content); 67 } 68 69 TEST(rename, FileOpenedForReadingCanBeReplaced) { 70 // Create unique temporary directory for this test. 71 SmallString<128> TestDirectory; 72 ASSERT_NO_ERROR(fs::createUniqueDirectory( 73 "FileOpenedForReadingCanBeReplaced-test", TestDirectory)); 74 75 // Add a couple of files to the test directory. 76 SmallString<128> SourceFileName(TestDirectory); 77 path::append(SourceFileName, "source"); 78 79 SmallString<128> TargetFileName(TestDirectory); 80 path::append(TargetFileName, "target"); 81 82 ASSERT_NO_ERROR(CreateFileWithContent(SourceFileName, "!!source!!")); 83 ASSERT_NO_ERROR(CreateFileWithContent(TargetFileName, "!!target!!")); 84 85 { 86 // Open the target file for reading. 87 int ReadFD = 0; 88 ASSERT_NO_ERROR(fs::openFileForRead(TargetFileName, ReadFD)); 89 ScopedFD EventuallyCloseIt(ReadFD); 90 91 // Confirm we can replace the file while it is open. 92 EXPECT_TRUE(!fs::rename(SourceFileName, TargetFileName)); 93 94 // We should still be able to read the old data through the existing 95 // descriptor. 96 EXPECT_TRUE(FDHasContent(ReadFD, "!!target!!")); 97 98 // The source file should no longer exist 99 EXPECT_FALSE(fs::exists(SourceFileName)); 100 } 101 102 // If we obtain a new descriptor for the target file, we should find that it 103 // contains the content that was in the source file. 104 EXPECT_TRUE(FileHasContent(TargetFileName, "!!source!!")); 105 106 // Rename the target file back to the source file name to confirm that rename 107 // still works if the destination does not already exist. 108 EXPECT_TRUE(!fs::rename(TargetFileName, SourceFileName)); 109 EXPECT_FALSE(fs::exists(TargetFileName)); 110 ASSERT_TRUE(fs::exists(SourceFileName)); 111 112 // Clean up. 113 ASSERT_NO_ERROR(fs::remove(SourceFileName)); 114 ASSERT_NO_ERROR(fs::remove(TestDirectory.str())); 115 } 116 117 TEST(rename, ExistingTemp) { 118 // Test that existing .tmpN files don't get deleted by the Windows 119 // sys::fs::rename implementation. 120 SmallString<128> TestDirectory; 121 ASSERT_NO_ERROR( 122 fs::createUniqueDirectory("ExistingTemp-test", TestDirectory)); 123 124 SmallString<128> SourceFileName(TestDirectory); 125 path::append(SourceFileName, "source"); 126 127 SmallString<128> TargetFileName(TestDirectory); 128 path::append(TargetFileName, "target"); 129 130 SmallString<128> TargetTmp0FileName(TestDirectory); 131 path::append(TargetTmp0FileName, "target.tmp0"); 132 133 SmallString<128> TargetTmp1FileName(TestDirectory); 134 path::append(TargetTmp1FileName, "target.tmp1"); 135 136 ASSERT_NO_ERROR(CreateFileWithContent(SourceFileName, "!!source!!")); 137 ASSERT_NO_ERROR(CreateFileWithContent(TargetFileName, "!!target!!")); 138 ASSERT_NO_ERROR(CreateFileWithContent(TargetTmp0FileName, "!!target.tmp0!!")); 139 140 { 141 // Use mapped_file_region to make sure that the destination file is mmap'ed. 142 // This will cause SetInformationByHandle to fail when renaming to the 143 // destination, and we will follow the code path that tries to give target 144 // a temporary name. 145 int TargetFD; 146 std::error_code EC; 147 ASSERT_NO_ERROR(fs::openFileForRead(TargetFileName, TargetFD)); 148 ScopedFD X(TargetFD); 149 sys::fs::mapped_file_region MFR( 150 TargetFD, sys::fs::mapped_file_region::readonly, 10, 0, EC); 151 ASSERT_FALSE(EC); 152 153 ASSERT_NO_ERROR(fs::rename(SourceFileName, TargetFileName)); 154 155 #ifdef _WIN32 156 // Make sure that target was temporarily renamed to target.tmp1 on Windows. 157 // This is signified by a permission denied error as opposed to no such file 158 // or directory when trying to open it. 159 int Tmp1FD; 160 EXPECT_EQ(errc::permission_denied, 161 fs::openFileForRead(TargetTmp1FileName, Tmp1FD)); 162 #endif 163 } 164 165 EXPECT_TRUE(FileHasContent(TargetTmp0FileName, "!!target.tmp0!!")); 166 167 ASSERT_NO_ERROR(fs::remove(TargetFileName)); 168 ASSERT_NO_ERROR(fs::remove(TargetTmp0FileName)); 169 ASSERT_NO_ERROR(fs::remove(TestDirectory.str())); 170 } 171 172 } // anonymous namespace 173