1 //===- Support/FileUtilities.cpp - File System Utilities ------------------===//
3 // This file implements a family of utility functions which are useful for doing
4 // various things with files.
6 //===----------------------------------------------------------------------===//
8 #include "Support/FileUtilities.h"
13 /// DiffFiles - Compare the two files specified, returning true if they are
14 /// different or if there is a file error. If you specify a string to fill in
15 /// for the error option, it will set the string to an error message if an error
16 /// occurs, allowing the caller to distinguish between a failed diff and a file
19 bool DiffFiles(const std::string &FileA, const std::string &FileB,
21 std::ifstream FileAStream(FileA.c_str());
23 if (Error) *Error = "Couldn't open file '" + FileA + "'";
27 std::ifstream FileBStream(FileB.c_str());
29 if (Error) *Error = "Couldn't open file '" + FileB + "'";
33 // Compare the two files...
36 C1 = FileAStream.get();
37 C2 = FileBStream.get();
38 if (C1 != C2) return true;
45 /// MoveFileOverIfUpdated - If the file specified by New is different than Old,
46 /// or if Old does not exist, move the New file over the Old file. Otherwise,
47 /// remove the New file.
49 void MoveFileOverIfUpdated(const std::string &New, const std::string &Old) {
50 if (DiffFiles(New, Old)) {
51 if (std::rename(New.c_str(), Old.c_str()))
52 std::cerr << "Error renaming '" << New << "' to '" << Old << "'!\n";
54 std::remove(New.c_str());
58 /// removeFile - Delete the specified file
60 void removeFile(const std::string &Filename) {
61 std::remove(Filename.c_str());
64 /// getUniqueFilename - Return a filename with the specified prefix. If the
65 /// file does not exist yet, return it, otherwise add a suffix to make it
68 std::string getUniqueFilename(const std::string &FilenameBase) {
69 if (!std::ifstream(FilenameBase.c_str()))
70 return FilenameBase; // Couldn't open the file? Use it!
72 // Create a pattern for mkstemp...
73 char *FNBuffer = new char[FilenameBase.size()+8];
74 strcpy(FNBuffer, FilenameBase.c_str());
75 strcpy(FNBuffer+FilenameBase.size(), "-XXXXXX");
77 // Agree on a temporary file name to use....
79 if ((TempFD = mkstemp(FNBuffer)) == -1) {
80 std::cerr << "bugpoint: ERROR: Cannot create temporary file in the current "
85 // We don't need to hold the temp file descriptor... we will trust that noone
86 // will overwrite/delete the file while we are working on it...
88 std::string Result(FNBuffer);