1 //===- ToolOutputFile.h - Output files for compiler-like tools -----------===//
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/ADT/Optional.h"
17 #include "llvm/Support/raw_ostream.h"
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     /// The name of the file.
33     std::string Filename;
34   public:
35     /// The flag which indicates whether we should not delete the file.
36     bool Keep;
37 
38     StringRef getFilename() { return Filename; }
39     explicit CleanupInstaller(StringRef Filename);
40     ~CleanupInstaller();
41   } Installer;
42 
43   /// Storage for the stream, if we're owning our own stream. This is
44   /// intentionally declared after Installer.
45   Optional<raw_fd_ostream> OSHolder;
46 
47   /// The actual stream to use.
48   raw_fd_ostream *OS;
49 
50 public:
51   /// This constructor's arguments are passed to raw_fd_ostream's
52   /// constructor.
53   ToolOutputFile(StringRef Filename, std::error_code &EC,
54                  sys::fs::OpenFlags Flags);
55 
56   ToolOutputFile(StringRef Filename, int FD);
57 
58   /// Return the contained raw_fd_ostream.
59   raw_fd_ostream &os() { return *OS; }
60 
61   /// Return the filename initialized with.
62   StringRef getFilename() { return Installer.getFilename(); }
63 
64   /// Indicate that the tool's job wrt this output file has been successful and
65   /// the file should not be deleted.
66   void keep() { Installer.Keep = true; }
67 };
68 
69 } // end llvm namespace
70 
71 #endif
72