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/Compiler.h"
19#include "llvm/Support/Error.h"
20#include "llvm/Support/FileSystem.h"
21
22#include <system_error>
23
24namespace llvm {
25
26/// DiffFilesWithTolerance - Compare the two files specified, returning 0 if
27/// the files match, 1 if they are different, and 2 if there is a file error.
28/// This function allows you to specify an absolute and relative FP error that
29/// is allowed to exist. If you specify a string to fill in for the error
30/// option, it will set the string to an error message if an error occurs, or
31/// if the files are different.
32///
33LLVM_ABI int DiffFilesWithTolerance(StringRef FileA, StringRef FileB,
34 double AbsTol, double RelTol,
35 std::string *Error = nullptr);
36
37/// FileRemover - This class is a simple object meant to be stack allocated.
38/// If an exception is thrown from a region, the object removes the filename
39/// specified (if deleteIt is true).
40///
41class FileRemover {
42 SmallString<128> Filename;
43 bool DeleteIt;
44
45public:
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.
82class FilePermissionsApplier {
83public:
84 LLVM_ABI static Expected<FilePermissionsApplier>
85 create(StringRef InputFilename);
86
87 /// Apply stored permissions to the \p OutputFilename.
88 /// Copy LastAccess and ModificationTime if \p CopyDates is true.
89 /// Overwrite stored permissions if \p OverwritePermissions is specified.
90 LLVM_ABI Error
91 apply(StringRef OutputFilename, bool CopyDates = false,
92 std::optional<sys::fs::perms> OverwritePermissions = std::nullopt);
93
94private:
95 FilePermissionsApplier(StringRef InputFilename, sys::fs::file_status Status)
96 : InputFilename(InputFilename), InputStatus(Status) {}
97
98 StringRef InputFilename;
99 sys::fs::file_status InputStatus;
100};
101} // namespace llvm
102
103#endif
104