FileUtilities.h revision 353358 
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/Support/FileSystem.h"
18#include "llvm/Support/Path.h"
19
20namespace llvm {
21
22  /// DiffFilesWithTolerance - Compare the two files specified, returning 0 if
23  /// the files match, 1 if they are different, and 2 if there is a file error.
24  /// This function allows you to specify an absolute and relative FP error that
25  /// is allowed to exist.  If you specify a string to fill in for the error
26  /// option, it will set the string to an error message if an error occurs, or
27  /// if the files are different.
28  ///
29  int DiffFilesWithTolerance(StringRef FileA,
30                             StringRef FileB,
31                             double AbsTol, double RelTol,
32                             std::string *Error = nullptr);
33
34
35  /// FileRemover - This class is a simple object meant to be stack allocated.
36  /// If an exception is thrown from a region, the object removes the filename
37  /// specified (if deleteIt is true).
38  ///
39  class FileRemover {
40    SmallString<128> Filename;
41    bool DeleteIt;
42  public:
43    FileRemover() : DeleteIt(false) {}
44
45    explicit FileRemover(const Twine& filename, bool deleteIt = true)
46      : DeleteIt(deleteIt) {
47      filename.toVector(Filename);
48    }
49
50    ~FileRemover() {
51      if (DeleteIt) {
52        // Ignore problems deleting the file.
53        sys::fs::remove(Filename);
54      }
55    }
56
57    /// setFile - Give ownership of the file to the FileRemover so it will
58    /// be removed when the object is destroyed.  If the FileRemover already
59    /// had ownership of a file, remove it first.
60    void setFile(const Twine& filename, bool deleteIt = true) {
61      if (DeleteIt) {
62        // Ignore problems deleting the file.
63        sys::fs::remove(Filename);
64      }
65
66      Filename.clear();
67      filename.toVector(Filename);
68      DeleteIt = deleteIt;
69    }
70
71    /// releaseFile - Take ownership of the file away from the FileRemover so it
72    /// will not be removed when the object is destroyed.
73    void releaseFile() { DeleteIt = false; }
74  };
75} // End llvm namespace
76
77#endif
78