X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2FFileUtilities.cpp;h=1736b0d5c31e2b0d99f23bb7158d624a990ab9b9;hb=92f7e8d92581e031beeee3dc6c170f5c2cc7ea18;hp=5255df64e5fe0a64235a10c9e81ec9d47ab4af73;hpb=772192cf36edeaed9366382914f820e1d81c605a;p=oota-llvm.git

diff --git a/lib/Support/FileUtilities.cpp b/lib/Support/FileUtilities.cpp
index 5255df64e5f..1736b0d5c31 100644
--- a/lib/Support/FileUtilities.cpp
+++ b/lib/Support/FileUtilities.cpp
@@ -1,10 +1,10 @@
 //===- Support/FileUtilities.cpp - File System Utilities ------------------===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by the LLVM research group and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+//
 //===----------------------------------------------------------------------===//
 //
 // This file implements a family of utility functions which are useful for doing
@@ -14,52 +14,253 @@
 
 #include "llvm/Support/FileUtilities.h"
 #include "llvm/System/Path.h"
-#include <fstream>
-#include <iostream>
-
+#include "llvm/System/MappedFile.h"
+#include "llvm/ADT/StringExtras.h"
+#include <cstring>
+#include <cctype>
 using namespace llvm;
 
-/// 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 llvm::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;
+static bool isNumberChar(char C) {
+  switch (C) {
+  case '0': case '1': case '2': case '3': case '4':
+  case '5': case '6': case '7': case '8': case '9':
+  case '.': case '+': case '-':
+  case 'D':  // Strange exponential notation.
+  case 'd':  // Strange exponential notation.
+  case 'e':
+  case 'E': return true;
+  default: return false;
   }
+}
+
+static char *BackupNumber(char *Pos, char *FirstChar) {
+  // If we didn't stop in the middle of a number, don't backup.
+  if (!isNumberChar(*Pos)) return Pos;
+
+  // Otherwise, return to the start of the number.
+  while (Pos > FirstChar && isNumberChar(Pos[-1]))
+    --Pos;
+  return Pos;
+}
+
+/// CompareNumbers - compare two numbers, returning true if they are different.
+static bool CompareNumbers(char *&F1P, char *&F2P, char *F1End, char *F2End,
+                           double AbsTolerance, double RelTolerance,
+                           std::string *ErrorMsg) {
+  char *F1NumEnd, *F2NumEnd;
+  double V1 = 0.0, V2 = 0.0;
+
+  // If one of the positions is at a space and the other isn't, chomp up 'til
+  // the end of the space.
+  while (isspace(*F1P) && F1P != F1End)
+    ++F1P;
+  while (isspace(*F2P) && F2P != F2End)
+    ++F2P;
 
-  std::ifstream FileBStream(FileB.c_str());
-  if (!FileBStream) {
-    if (Error) *Error = "Couldn't open file '" + FileB + "'";
+  // If we stop on numbers, compare their difference.  Note that some ugliness
+  // is built into this to permit support for numbers that use "D" or "d" as
+  // their exponential marker, e.g. "1.234D45".  This occurs in 200.sixtrack in
+  // spec2k.
+  if (isNumberChar(*F1P) && isNumberChar(*F2P)) {
+    bool isDNotation;
+    do {
+      isDNotation = false;
+      V1 = strtod(F1P, &F1NumEnd);
+      V2 = strtod(F2P, &F2NumEnd);
+
+      if (*F1NumEnd == 'D' || *F1NumEnd == 'd') {
+        *F1NumEnd = 'e';  // Strange exponential notation!
+        isDNotation = true;
+      }
+      if (*F2NumEnd == 'D' || *F2NumEnd == 'd') {
+        *F2NumEnd = 'e';  // Strange exponential notation!
+        isDNotation = true;
+      }
+    } while (isDNotation);
+  } else {
+    // Otherwise, the diff failed.
+    F1NumEnd = F1P;
+    F2NumEnd = F2P;
+  }
+
+  if (F1NumEnd == F1P || F2NumEnd == F2P) {
+    if (ErrorMsg) {
+      *ErrorMsg = "FP Comparison failed, not a numeric difference between '";
+      *ErrorMsg += F1P[0];
+      *ErrorMsg += "' and '";
+      *ErrorMsg += F2P[0];
+      *ErrorMsg += "'";
+    }
     return true;
   }
 
-  // Compare the two files...
-  int C1, C2;
-  do {
-    C1 = FileAStream.get();
-    C2 = FileBStream.get();
-    if (C1 != C2) return true;
-  } while (C1 != EOF);
+  // Check to see if these are inside the absolute tolerance
+  if (AbsTolerance < std::abs(V1-V2)) {
+    // Nope, check the relative tolerance...
+    double Diff;
+    if (V2)
+      Diff = std::abs(V1/V2 - 1.0);
+    else if (V1)
+      Diff = std::abs(V2/V1 - 1.0);
+    else
+      Diff = 0;  // Both zero.
+    if (Diff > RelTolerance) {
+      if (ErrorMsg) {
+        *ErrorMsg = "Compared: " + ftostr(V1) + " and " + ftostr(V2) + "\n";
+        *ErrorMsg += "abs. diff = " + ftostr(std::abs(V1-V2)) + 
+                     " rel.diff = " + ftostr(Diff) + "\n";
+        *ErrorMsg += "Out of tolerance: rel/abs: " + ftostr(RelTolerance) +
+                     "/" + ftostr(AbsTolerance);
+      }
+      return true;
+    }
+  }
 
+  // Otherwise, advance our read pointers to the end of the numbers.
+  F1P = F1NumEnd;  F2P = F2NumEnd;
   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.
+// PadFileIfNeeded - If the files are not identical, we will have to be doing
+// numeric comparisons in here.  There are bad cases involved where we (i.e.,
+// strtod) might run off the beginning or end of the file if it starts or ends
+// with a number.  Because of this, if needed, we pad the file so that it starts
+// and ends with a null character.
+static void PadFileIfNeeded(char *&FileStart, char *&FileEnd, char *&FP) {
+  if (FileStart-FileEnd < 2 ||
+      isNumberChar(FileStart[0]) || isNumberChar(FileEnd[-1])) {
+    unsigned FileLen = FileEnd-FileStart;
+    char *NewFile = new char[FileLen+2];
+    NewFile[0] = 0;              // Add null padding
+    NewFile[FileLen+1] = 0;      // Add null padding
+    memcpy(NewFile+1, FileStart, FileLen);
+    FP = NewFile+(FP-FileStart)+1;
+    FileStart = NewFile+1;
+    FileEnd = FileStart+FileLen;
+  }
+}
+
+/// DiffFilesWithTolerance - Compare the two files specified, returning 0 if the
+/// files match, 1 if they are different, and 2 if there is a file error.  This
+/// function differs from DiffFiles in that you can specify an absolete and
+/// relative FP error that is allowed to exist.  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.
 ///
-void llvm::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());
-  }  
+int llvm::DiffFilesWithTolerance(const sys::PathWithStatus &FileA,
+                                 const sys::PathWithStatus &FileB,
+                                 double AbsTol, double RelTol,
+                                 std::string *Error) {
+  const sys::FileStatus *FileAStat = FileA.getFileStatus(false, Error);
+  if (!FileAStat)
+    return 2;
+  const sys::FileStatus *FileBStat = FileB.getFileStatus(false, Error);
+  if (!FileBStat)
+    return 2;
+
+  // Check for zero length files because some systems croak when you try to
+  // mmap an empty file.
+  size_t A_size = FileAStat->getSize();
+  size_t B_size = FileBStat->getSize();
+
+  // If they are both zero sized then they're the same
+  if (A_size == 0 && B_size == 0)
+    return 0;
+
+  // If only one of them is zero sized then they can't be the same
+  if ((A_size == 0 || B_size == 0)) {
+    if (Error)
+      *Error = "Files differ: one is zero-sized, the other isn't";
+    return 1;
+  }
+
+  // Now its safe to mmap the files into memory becasue both files
+  // have a non-zero size.
+  sys::MappedFile F1;
+  if (F1.open(FileA, sys::MappedFile::READ_ACCESS, Error))
+    return 2;
+  sys::MappedFile F2;
+  if (F2.open(FileB, sys::MappedFile::READ_ACCESS, Error))
+    return 2;
+  if (!F1.map(Error))
+    return 2;
+  if (!F2.map(Error))
+    return 2;
+
+  // Okay, now that we opened the files, scan them for the first difference.
+  char *File1Start = F1.charBase();
+  char *File2Start = F2.charBase();
+  char *File1End = File1Start+A_size;
+  char *File2End = File2Start+B_size;
+  char *F1P = File1Start;
+  char *F2P = File2Start;
+
+  if (A_size == B_size) {
+    // Are the buffers identical?
+    if (std::memcmp(File1Start, File2Start, A_size) == 0)
+      return 0;
+
+    if (AbsTol == 0 && RelTol == 0) {
+      if (Error)
+        *Error = "Files differ without tolerance allowance";
+      return 1;   // Files different!
+    }
+  }
+
+  char *OrigFile1Start = File1Start;
+  char *OrigFile2Start = File2Start;
+
+  // If the files need padding, do so now.
+  PadFileIfNeeded(File1Start, File1End, F1P);
+  PadFileIfNeeded(File2Start, File2End, F2P);
+
+  bool CompareFailed = false;
+  while (1) {
+    // Scan for the end of file or next difference.
+    while (F1P < File1End && F2P < File2End && *F1P == *F2P)
+      ++F1P, ++F2P;
+
+    if (F1P >= File1End || F2P >= File2End) break;
+
+    // Okay, we must have found a difference.  Backup to the start of the
+    // current number each stream is at so that we can compare from the
+    // beginning.
+    F1P = BackupNumber(F1P, File1Start);
+    F2P = BackupNumber(F2P, File2Start);
+
+    // Now that we are at the start of the numbers, compare them, exiting if
+    // they don't match.
+    if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) {
+      CompareFailed = true;
+      break;
+    }
+  }
+
+  // Okay, we reached the end of file.  If both files are at the end, we
+  // succeeded.
+  bool F1AtEnd = F1P >= File1End;
+  bool F2AtEnd = F2P >= File2End;
+  if (!CompareFailed && (!F1AtEnd || !F2AtEnd)) {
+    // Else, we might have run off the end due to a number: backup and retry.
+    if (F1AtEnd && isNumberChar(F1P[-1])) --F1P;
+    if (F2AtEnd && isNumberChar(F2P[-1])) --F2P;
+    F1P = BackupNumber(F1P, File1Start);
+    F2P = BackupNumber(F2P, File2Start);
+
+    // Now that we are at the start of the numbers, compare them, exiting if
+    // they don't match.
+    if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error))
+      CompareFailed = true;
+
+    // If we found the end, we succeeded.
+    if (F1P < File1End || F2P < File2End)
+      CompareFailed = true;
+  }
+
+  if (OrigFile1Start != File1Start)
+    delete[] (File1Start-1);   // Back up past null byte
+  if (OrigFile2Start != File2Start)
+    delete[] (File2Start-1);   // Back up past null byte
+  return CompareFailed;
 }