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"
9 #include "Config/unistd.h"
14 /// DiffFiles - Compare the two files specified, returning true if they are
15 /// different or if there is a file error. If you specify a string to fill in
16 /// for the error option, it will set the string to an error message if an error
17 /// occurs, allowing the caller to distinguish between a failed diff and a file
20 bool DiffFiles(const std::string &FileA, const std::string &FileB,
22 std::ifstream FileAStream(FileA.c_str());
24 if (Error) *Error = "Couldn't open file '" + FileA + "'";
28 std::ifstream FileBStream(FileB.c_str());
30 if (Error) *Error = "Couldn't open file '" + FileB + "'";
34 // Compare the two files...
37 C1 = FileAStream.get();
38 C2 = FileBStream.get();
39 if (C1 != C2) return true;
46 /// MoveFileOverIfUpdated - If the file specified by New is different than Old,
47 /// or if Old does not exist, move the New file over the Old file. Otherwise,
48 /// remove the New file.
50 void MoveFileOverIfUpdated(const std::string &New, const std::string &Old) {
51 if (DiffFiles(New, Old)) {
52 if (std::rename(New.c_str(), Old.c_str()))
53 std::cerr << "Error renaming '" << New << "' to '" << Old << "'!\n";
55 std::remove(New.c_str());
59 /// removeFile - Delete the specified file
61 void removeFile(const std::string &Filename) {
62 std::remove(Filename.c_str());
65 /// getUniqueFilename - Return a filename with the specified prefix. If the
66 /// file does not exist yet, return it, otherwise add a suffix to make it
69 std::string getUniqueFilename(const std::string &FilenameBase) {
70 if (!std::ifstream(FilenameBase.c_str()))
71 return FilenameBase; // Couldn't open the file? Use it!
73 // Create a pattern for mkstemp...
74 char *FNBuffer = new char[FilenameBase.size()+8];
75 strcpy(FNBuffer, FilenameBase.c_str());
76 strcpy(FNBuffer+FilenameBase.size(), "-XXXXXX");
78 // Agree on a temporary file name to use....
80 if ((TempFD = mkstemp(FNBuffer)) == -1) {
81 std::cerr << "bugpoint: ERROR: Cannot create temporary file in the current "
86 // We don't need to hold the temp file descriptor... we will trust that noone
87 // will overwrite/delete the file while we are working on it...
89 std::string Result(FNBuffer);