forked from OSchip/llvm-project
93 lines
2.8 KiB
C++
93 lines
2.8 KiB
C++
//===- Support/FileUtilities.cpp - File System Utilities ------------------===//
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//
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// This file implements a family of utility functions which are useful for doing
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// various things with files.
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//
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//===----------------------------------------------------------------------===//
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#include "Support/FileUtilities.h"
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#include "Config/unistd.h"
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#include <fstream>
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#include <iostream>
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#include <cstdio>
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/// DiffFiles - Compare the two files specified, returning true if they are
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/// different or if there is a file error. If you specify a string to fill in
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/// for the error option, it will set the string to an error message if an error
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/// occurs, allowing the caller to distinguish between a failed diff and a file
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/// system error.
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///
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bool DiffFiles(const std::string &FileA, const std::string &FileB,
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std::string *Error) {
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std::ifstream FileAStream(FileA.c_str());
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if (!FileAStream) {
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if (Error) *Error = "Couldn't open file '" + FileA + "'";
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return true;
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}
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std::ifstream FileBStream(FileB.c_str());
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if (!FileBStream) {
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if (Error) *Error = "Couldn't open file '" + FileB + "'";
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return true;
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}
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// Compare the two files...
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int C1, C2;
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do {
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C1 = FileAStream.get();
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C2 = FileBStream.get();
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if (C1 != C2) return true;
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} while (C1 != EOF);
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return false;
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}
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/// MoveFileOverIfUpdated - If the file specified by New is different than Old,
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/// or if Old does not exist, move the New file over the Old file. Otherwise,
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/// remove the New file.
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///
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void MoveFileOverIfUpdated(const std::string &New, const std::string &Old) {
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if (DiffFiles(New, Old)) {
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if (std::rename(New.c_str(), Old.c_str()))
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std::cerr << "Error renaming '" << New << "' to '" << Old << "'!\n";
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} else {
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std::remove(New.c_str());
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}
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}
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/// removeFile - Delete the specified file
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///
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void removeFile(const std::string &Filename) {
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std::remove(Filename.c_str());
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}
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/// getUniqueFilename - Return a filename with the specified prefix. If the
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/// file does not exist yet, return it, otherwise add a suffix to make it
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/// unique.
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///
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std::string getUniqueFilename(const std::string &FilenameBase) {
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if (!std::ifstream(FilenameBase.c_str()))
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return FilenameBase; // Couldn't open the file? Use it!
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// Create a pattern for mkstemp...
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char *FNBuffer = new char[FilenameBase.size()+8];
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strcpy(FNBuffer, FilenameBase.c_str());
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strcpy(FNBuffer+FilenameBase.size(), "-XXXXXX");
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// Agree on a temporary file name to use....
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int TempFD;
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if ((TempFD = mkstemp(FNBuffer)) == -1) {
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std::cerr << "bugpoint: ERROR: Cannot create temporary file in the current "
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<< " directory!\n";
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exit(1);
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}
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// We don't need to hold the temp file descriptor... we will trust that noone
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// will overwrite/delete the file while we are working on it...
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close(TempFD);
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std::string Result(FNBuffer);
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delete[] FNBuffer;
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return Result;
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}
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