1 //===- ToolOutputFile.h - Output files for compiler-like tools --*- 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 the ToolOutputFile class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_SUPPORT_TOOLOUTPUTFILE_H
14 #define LLVM_SUPPORT_TOOLOUTPUTFILE_H
15 
16 #include "llvm/Support/raw_ostream.h"
17 #include <optional>
18 
19 namespace llvm {
20 
21 /// This class contains a raw_fd_ostream and adds a few extra features commonly
22 /// needed for compiler-like tool output files:
23 ///   - The file is automatically deleted if the process is killed.
24 ///   - The file is automatically deleted when the ToolOutputFile
25 ///     object is destroyed unless the client calls keep().
26 class ToolOutputFile {
27   /// This class is declared before the raw_fd_ostream so that it is constructed
28   /// before the raw_fd_ostream is constructed and destructed after the
29   /// raw_fd_ostream is destructed. It installs cleanups in its constructor and
30   /// uninstalls them in its destructor.
31   class CleanupInstaller {
32   public:
33     /// The name of the file.
34     std::string Filename;
35 
36     /// The flag which indicates whether we should not delete the file.
37     bool Keep;
38 
getFilename()39     StringRef getFilename() { return Filename; }
40     explicit CleanupInstaller(StringRef Filename);
41     ~CleanupInstaller();
42   } Installer;
43 
44   /// Storage for the stream, if we're owning our own stream. This is
45   /// intentionally declared after Installer.
46   std::optional<raw_fd_ostream> OSHolder;
47 
48   /// The actual stream to use.
49   raw_fd_ostream *OS;
50 
51 public:
52   /// This constructor's arguments are passed to raw_fd_ostream's
53   /// constructor.
54   ToolOutputFile(StringRef Filename, std::error_code &EC,
55                  sys::fs::OpenFlags Flags);
56 
57   ToolOutputFile(StringRef Filename, int FD);
58 
59   /// Return the contained raw_fd_ostream.
os()60   raw_fd_ostream &os() { return *OS; }
61 
62   /// Return the filename initialized with.
getFilename()63   StringRef getFilename() { return Installer.getFilename(); }
64 
65   /// Indicate that the tool's job wrt this output file has been successful and
66   /// the file should not be deleted.
keep()67   void keep() { Installer.Keep = true; }
68 
outputFilename()69   const std::string &outputFilename() { return Installer.Filename; }
70 };
71 
72 } // end llvm namespace
73 
74 #endif
75