[llvm-commits] CVS: llvm/lib/Support/FileUtilities.cpp

[Chris Lattner]

Changes in directory llvm/lib/Support:

FileUtilities.cpp added (r1.1)

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Log message:

Check in the implementation of the FileUtilities!


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Diffs of the changes:

Index: llvm/lib/Support/FileUtilities.cpp
diff -c /dev/null llvm/lib/Support/FileUtilities.cpp:1.1
*** /dev/null	Fri Aug  1 16:16:26 2003
--- llvm/lib/Support/FileUtilities.cpp	Fri Aug  1 16:16:14 2003
***************
*** 0 ****
--- 1,56 ----
+ //===- Support/FileUtilities.cpp - File System Utilities ------------------===//
+ //
+ // This file implements a family of utility functions which are useful for doing
+ // various things with files.
+ //
+ //===----------------------------------------------------------------------===//
+ 
+ #include "Support/FileUtilities.h"
+ #include <fstream>
+ #include <iostream>
+ #include <cstdio>
+ 
+ /// DiffFiles - Compare the two files specified, returning true if they are
+ /// different or if there is a file error.  If you specify a string to fill in
+ /// for the error option, it will set the string to an error message if an error
+ /// occurs, allowing the caller to distinguish between a failed diff and a file
+ /// system error.
+ ///
+ bool DiffFiles(const std::string &FileA, const std::string &FileB,
+                std::string *Error) {
+   std::ifstream FileAStream(FileA.c_str());
+   if (!FileAStream) {
+     if (Error) *Error = "Couldn't open file '" + FileA + "'";
+     return true;
+   }
+ 
+   std::ifstream FileBStream(FileB.c_str());
+   if (!FileBStream) {
+     if (Error) *Error = "Couldn't open file '" + FileB + "'";
+     return true;
+   }
+ 
+   // Compare the two files...
+   int C1, C2;
+   do {
+     C1 = FileAStream.get();
+     C2 = FileBStream.get();
+     if (C1 != C2) return true;
+   } while (C1 != EOF);
+ 
+   return false;
+ }
+ 
+ 
+ /// MoveFileOverIfUpdated - If the file specified by New is different than Old,
+ /// or if Old does not exist, move the New file over the Old file.  Otherwise,
+ /// remove the New file.
+ ///
+ void MoveFileOverIfUpdated(const std::string &New, const std::string &Old) {
+   if (DiffFiles(New, Old)) {
+     if (std::rename(New.c_str(), Old.c_str()))
+       std::cerr << "Error renaming '" << New << "' to '" << Old << "'!\n";
+   } else {
+     std::remove(New.c_str());
+   }  
+ }