1//===- llvm/Support/FileUtilities.h - File System Utilities -----*- C++ -*-===//
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// This file defines a family of utility functions which are useful for doing
10// various things with files.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_FILEUTILITIES_H
15#define LLVM_SUPPORT_FILEUTILITIES_H
16
17#include "llvm/ADT/StringRef.h"
18#include "llvm/Support/Error.h"
19#include "llvm/Support/FileSystem.h"
20
21#include <system_error>
22
23namespace llvm {
24
25 /// DiffFilesWithTolerance - Compare the two files specified, returning 0 if
26 /// the files match, 1 if they are different, and 2 if there is a file error.
27 /// This function allows you to specify an absolute and relative FP error that
28 /// is allowed to exist. If you specify a string to fill in for the error
29 /// option, it will set the string to an error message if an error occurs, or
30 /// if the files are different.
31 ///
32 int DiffFilesWithTolerance(StringRef FileA,
33 StringRef FileB,
34 double AbsTol, double RelTol,
35 std::string *Error = nullptr);
36
37
38 /// FileRemover - This class is a simple object meant to be stack allocated.
39 /// If an exception is thrown from a region, the object removes the filename
40 /// specified (if deleteIt is true).
41 ///
42 class FileRemover {
43 SmallString<128> Filename;
44 bool DeleteIt;
45 public:
46 FileRemover() : DeleteIt(false) {}
47
48 explicit FileRemover(const Twine& filename, bool deleteIt = true)
49 : DeleteIt(deleteIt) {
50 filename.toVector(Out&: Filename);
51 }
52
53 ~FileRemover() {
54 if (DeleteIt) {
55 // Ignore problems deleting the file.
56 sys::fs::remove(path: Filename);
57 }
58 }
59
60 /// setFile - Give ownership of the file to the FileRemover so it will
61 /// be removed when the object is destroyed. If the FileRemover already
62 /// had ownership of a file, remove it first.
63 void setFile(const Twine& filename, bool deleteIt = true) {
64 if (DeleteIt) {
65 // Ignore problems deleting the file.
66 sys::fs::remove(path: Filename);
67 }
68
69 Filename.clear();
70 filename.toVector(Out&: Filename);
71 DeleteIt = deleteIt;
72 }
73
74 /// releaseFile - Take ownership of the file away from the FileRemover so it
75 /// will not be removed when the object is destroyed.
76 void releaseFile() { DeleteIt = false; }
77 };
78
79 /// FilePermssionsApplier helps to copy permissions from an input file to
80 /// an output one. It memorizes the status of the input file and can apply
81 /// permissions and dates to the output file.
82 class FilePermissionsApplier {
83 public:
84 static Expected<FilePermissionsApplier> create(StringRef InputFilename);
85
86 /// Apply stored permissions to the \p OutputFilename.
87 /// Copy LastAccess and ModificationTime if \p CopyDates is true.
88 /// Overwrite stored permissions if \p OverwritePermissions is specified.
89 Error
90 apply(StringRef OutputFilename, bool CopyDates = false,
91 std::optional<sys::fs::perms> OverwritePermissions = std::nullopt);
92
93 private:
94 FilePermissionsApplier(StringRef InputFilename, sys::fs::file_status Status)
95 : InputFilename(InputFilename), InputStatus(Status) {}
96
97 StringRef InputFilename;
98 sys::fs::file_status InputStatus;
99 };
100} // End llvm namespace
101
102#endif
103