1 //===- Support/FileUtilities.h - File System Utilities ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a family of utility functions which are useful for doing
11 // various things with files.
13 //===----------------------------------------------------------------------===//
15 #ifndef SUPPORT_FILEUTILITIES_H
16 #define SUPPORT_FILEUTILITIES_H
22 /// CheckMagic - Returns true IFF the file named FN begins with Magic. FN must
23 /// name a readable file.
25 bool CheckMagic (const std::string &FN, const std::string &Magic);
27 /// IsArchive - Returns true IFF the file named FN appears to be a "ar" library
28 /// archive. The file named FN must exist.
30 bool IsArchive (const std::string &FN);
32 /// IsBytecode - Returns true IFF the file named FN appears to be an LLVM
33 /// bytecode file. The file named FN must exist.
35 bool IsBytecode (const std::string &FN);
37 /// IsSharedObject - Returns trus IFF the file named FN appears to be a shared
38 /// object with an ELF header. The file named FN must exist.
40 bool IsSharedObject(const std::string &FN);
42 /// FileOpenable - Returns true IFF Filename names an existing regular file
43 /// which we can successfully open.
45 bool FileOpenable(const std::string &Filename);
47 /// DiffFiles - Compare the two files specified, returning true if they are
48 /// different or if there is a file error. If you specify a string to fill in
49 /// for the error option, it will set the string to an error message if an error
50 /// occurs, allowing the caller to distinguish between a failed diff and a file
53 bool DiffFiles(const std::string &FileA, const std::string &FileB,
54 std::string *Error = 0);
57 /// MoveFileOverIfUpdated - If the file specified by New is different than Old,
58 /// or if Old does not exist, move the New file over the Old file. Otherwise,
59 /// remove the New file.
61 void MoveFileOverIfUpdated(const std::string &New, const std::string &Old);
63 /// removeFile - Delete the specified file
65 void removeFile(const std::string &Filename);
67 /// getUniqueFilename - Return a filename with the specified prefix. If the
68 /// file does not exist yet, return it, otherwise add a suffix to make it
71 std::string getUniqueFilename(const std::string &FilenameBase);
73 /// MakeFileExecutable - This method turns on whatever access attributes are
74 /// needed to make the specified file executable. It returns true on success.
75 /// In case of failure, the file's access attributes are unspecified.
77 bool MakeFileExecutable(const std::string &Filename);
79 /// MakeFileReadable - This method turns on whatever access attributes are
80 /// needed to make the specified file readable. It returns true on success.
81 /// In case of failure, the file's access attributes are unspecified.
83 bool MakeFileReadable(const std::string &Filename);
85 /// getFileSize - Return the size of the specified file in bytes, or -1 if the
86 /// file cannot be read or does not exist.
87 long long getFileSize(const std::string &Filename);
90 /// getFileTimestamp - Get the last modified time for the specified file in an
91 /// unspecified format. This is useful to allow checking to see if a file was
92 /// updated since that last time the timestampt was aquired. If the file does
93 /// not exist or there is an error getting the time-stamp, zero is returned.
94 unsigned long long getFileTimestamp(const std::string &Filename);
96 /// ReadFileIntoAddressSpace - Attempt to map the specific file into the
97 /// address space of the current process for reading. If this succeeds,
98 /// return the address of the buffer and the length of the file mapped. On
99 /// failure, return null.
100 void *ReadFileIntoAddressSpace(const std::string &Filename, unsigned &Length);
102 /// UnmapFileFromAddressSpace - Remove the specified file from the current
104 void UnmapFileFromAddressSpace(void *Buffer, unsigned Length);
107 /// FDHandle - Simple handle class to make sure a file descriptor gets closed
108 /// when the object is destroyed. This handle acts similarly to an
109 /// std::auto_ptr, in that the copy constructor and assignment operators
110 /// transfer ownership of the handle. This means that FDHandle's do not have
116 FDHandle() : FD(-1) {}
117 FDHandle(int fd) : FD(fd) {}
118 FDHandle(FDHandle &RHS) : FD(RHS.FD) {
119 RHS.FD = -1; // Transfer ownership
124 /// get - Get the current file descriptor, without releasing ownership of it.
125 int get() const { return FD; }
126 operator int() const { return FD; }
128 FDHandle &operator=(int fd) throw();
130 FDHandle &operator=(FDHandle &RHS) {
132 RHS.FD = -1; // Transfer ownership
133 return operator=(fd);
136 /// release - Take ownership of the file descriptor away from the FDHandle
137 /// object, so that the file is not closed when the FDHandle is destroyed.
145 /// FileRemover - This class is a simple object meant to be stack allocated.
146 /// If an exception is thrown from a region, the object removes the filename
147 /// specified (if deleteIt is true).
150 std::string Filename;
153 FileRemover(const std::string &filename, bool deleteIt = true)
154 : Filename(filename), DeleteIt(deleteIt) {}
157 if (DeleteIt) removeFile(Filename);
160 /// releaseFile - Take ownership of the file away from the FileRemover so it
161 /// will not be removed when the object is destroyed.
162 void releaseFile() { DeleteIt = false; }
164 } // End llvm namespace