1 //===- llvm/unittest/Support/ReplaceFileTest.cpp - unit 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/Errc.h"
11 #include "llvm/Support/ErrorHandling.h"
12 #include "llvm/Support/FileSystem.h"
13 #include "llvm/Support/MemoryBuffer.h"
14 #include "llvm/Support/Path.h"
15 #include "llvm/Support/Process.h"
16 #include "gtest/gtest.h"
17
18 using namespace llvm;
19 using namespace llvm::sys;
20
21 #define ASSERT_NO_ERROR(x) \
22 do { \
23 if (std::error_code ASSERT_NO_ERROR_ec = x) { \
24 errs() << #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 } \
28 } while (false)
29
30 namespace {
CreateFileWithContent(const SmallString<128> & FilePath,const StringRef & content)31 std::error_code CreateFileWithContent(const SmallString<128> &FilePath,
32 const StringRef &content) {
33 int FD = 0;
34 if (std::error_code ec = fs::openFileForWrite(FilePath, FD, fs::F_None))
35 return ec;
36
37 const bool ShouldClose = true;
38 raw_fd_ostream OS(FD, ShouldClose);
39 OS << content;
40
41 return std::error_code();
42 }
43
44 class ScopedFD {
45 int FD;
46
47 ScopedFD(const ScopedFD &) = delete;
48 ScopedFD &operator=(const ScopedFD &) = delete;
49
50 public:
ScopedFD(int Descriptor)51 explicit ScopedFD(int Descriptor) : FD(Descriptor) {}
~ScopedFD()52 ~ScopedFD() { Process::SafelyCloseFileDescriptor(FD); }
53 };
54
TEST(rename,FileOpenedForReadingCanBeReplaced)55 TEST(rename, FileOpenedForReadingCanBeReplaced) {
56 // Create unique temporary directory for this test.
57 SmallString<128> TestDirectory;
58 ASSERT_NO_ERROR(fs::createUniqueDirectory(
59 "FileOpenedForReadingCanBeReplaced-test", TestDirectory));
60
61 // Add a couple of files to the test directory.
62 SmallString<128> SourceFileName(TestDirectory);
63 path::append(SourceFileName, "source");
64
65 SmallString<128> TargetFileName(TestDirectory);
66 path::append(TargetFileName, "target");
67
68 ASSERT_NO_ERROR(CreateFileWithContent(SourceFileName, "!!source!!"));
69 ASSERT_NO_ERROR(CreateFileWithContent(TargetFileName, "!!target!!"));
70
71 {
72 // Open the target file for reading.
73 int ReadFD = 0;
74 ASSERT_NO_ERROR(fs::openFileForRead(TargetFileName, ReadFD));
75 ScopedFD EventuallyCloseIt(ReadFD);
76
77 // Confirm we can replace the file while it is open.
78 EXPECT_TRUE(!fs::rename(SourceFileName, TargetFileName));
79
80 // We should still be able to read the old data through the existing
81 // descriptor.
82 auto Buffer = MemoryBuffer::getOpenFile(ReadFD, TargetFileName, -1);
83 ASSERT_TRUE(static_cast<bool>(Buffer));
84 EXPECT_EQ(Buffer.get()->getBuffer(), "!!target!!");
85
86 // The source file should no longer exist
87 EXPECT_FALSE(fs::exists(SourceFileName));
88 }
89
90 {
91 // If we obtain a new descriptor for the target file, we should find that it
92 // contains the content that was in the source file.
93 int ReadFD = 0;
94 ASSERT_NO_ERROR(fs::openFileForRead(TargetFileName, ReadFD));
95 ScopedFD EventuallyCloseIt(ReadFD);
96 auto Buffer = MemoryBuffer::getOpenFile(ReadFD, TargetFileName, -1);
97 ASSERT_TRUE(static_cast<bool>(Buffer));
98
99 EXPECT_EQ(Buffer.get()->getBuffer(), "!!source!!");
100 }
101
102 // Rename the target file back to the source file name to confirm that rename
103 // still works if the destination does not already exist.
104 EXPECT_TRUE(!fs::rename(TargetFileName, SourceFileName));
105 EXPECT_FALSE(fs::exists(TargetFileName));
106 ASSERT_TRUE(fs::exists(SourceFileName));
107
108 // Clean up.
109 ASSERT_NO_ERROR(fs::remove(SourceFileName));
110 ASSERT_NO_ERROR(fs::remove(TestDirectory.str()));
111 }
112
113 } // anonymous namespace
114