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FileUtilities.cpp
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1 //===- Support/FileUtilities.cpp - File System Utilities ------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements a family of utility functions which are useful for doing
11 // various things with files.
12 //
13 //===----------------------------------------------------------------------===//
14 
16 #include "llvm/ADT/OwningPtr.h"
17 #include "llvm/ADT/SmallString.h"
19 #include "llvm/Support/Path.h"
22 #include <cctype>
23 #include <cstdlib>
24 #include <cstring>
25 using namespace llvm;
26 
27 static bool isSignedChar(char C) {
28  return (C == '+' || C == '-');
29 }
30 
31 static bool isExponentChar(char C) {
32  switch (C) {
33  case 'D': // Strange exponential notation.
34  case 'd': // Strange exponential notation.
35  case 'e':
36  case 'E': return true;
37  default: return false;
38  }
39 }
40 
41 static bool isNumberChar(char C) {
42  switch (C) {
43  case '0': case '1': case '2': case '3': case '4':
44  case '5': case '6': case '7': case '8': case '9':
45  case '.': return true;
46  default: return isSignedChar(C) || isExponentChar(C);
47  }
48 }
49 
50 static const char *BackupNumber(const char *Pos, const char *FirstChar) {
51  // If we didn't stop in the middle of a number, don't backup.
52  if (!isNumberChar(*Pos)) return Pos;
53 
54  // Otherwise, return to the start of the number.
55  bool HasPeriod = false;
56  while (Pos > FirstChar && isNumberChar(Pos[-1])) {
57  // Backup over at most one period.
58  if (Pos[-1] == '.') {
59  if (HasPeriod)
60  break;
61  HasPeriod = true;
62  }
63 
64  --Pos;
65  if (Pos > FirstChar && isSignedChar(Pos[0]) && !isExponentChar(Pos[-1]))
66  break;
67  }
68  return Pos;
69 }
70 
71 /// EndOfNumber - Return the first character that is not part of the specified
72 /// number. This assumes that the buffer is null terminated, so it won't fall
73 /// off the end.
74 static const char *EndOfNumber(const char *Pos) {
75  while (isNumberChar(*Pos))
76  ++Pos;
77  return Pos;
78 }
79 
80 /// CompareNumbers - compare two numbers, returning true if they are different.
81 static bool CompareNumbers(const char *&F1P, const char *&F2P,
82  const char *F1End, const char *F2End,
83  double AbsTolerance, double RelTolerance,
84  std::string *ErrorMsg) {
85  const char *F1NumEnd, *F2NumEnd;
86  double V1 = 0.0, V2 = 0.0;
87 
88  // If one of the positions is at a space and the other isn't, chomp up 'til
89  // the end of the space.
90  while (isspace(static_cast<unsigned char>(*F1P)) && F1P != F1End)
91  ++F1P;
92  while (isspace(static_cast<unsigned char>(*F2P)) && F2P != F2End)
93  ++F2P;
94 
95  // If we stop on numbers, compare their difference.
96  if (!isNumberChar(*F1P) || !isNumberChar(*F2P)) {
97  // The diff failed.
98  F1NumEnd = F1P;
99  F2NumEnd = F2P;
100  } else {
101  // Note that some ugliness is built into this to permit support for numbers
102  // that use "D" or "d" as their exponential marker, e.g. "1.234D45". This
103  // occurs in 200.sixtrack in spec2k.
104  V1 = strtod(F1P, const_cast<char**>(&F1NumEnd));
105  V2 = strtod(F2P, const_cast<char**>(&F2NumEnd));
106 
107  if (*F1NumEnd == 'D' || *F1NumEnd == 'd') {
108  // Copy string into tmp buffer to replace the 'D' with an 'e'.
109  SmallString<200> StrTmp(F1P, EndOfNumber(F1NumEnd)+1);
110  // Strange exponential notation!
111  StrTmp[static_cast<unsigned>(F1NumEnd-F1P)] = 'e';
112 
113  V1 = strtod(&StrTmp[0], const_cast<char**>(&F1NumEnd));
114  F1NumEnd = F1P + (F1NumEnd-&StrTmp[0]);
115  }
116 
117  if (*F2NumEnd == 'D' || *F2NumEnd == 'd') {
118  // Copy string into tmp buffer to replace the 'D' with an 'e'.
119  SmallString<200> StrTmp(F2P, EndOfNumber(F2NumEnd)+1);
120  // Strange exponential notation!
121  StrTmp[static_cast<unsigned>(F2NumEnd-F2P)] = 'e';
122 
123  V2 = strtod(&StrTmp[0], const_cast<char**>(&F2NumEnd));
124  F2NumEnd = F2P + (F2NumEnd-&StrTmp[0]);
125  }
126  }
127 
128  if (F1NumEnd == F1P || F2NumEnd == F2P) {
129  if (ErrorMsg) {
130  *ErrorMsg = "FP Comparison failed, not a numeric difference between '";
131  *ErrorMsg += F1P[0];
132  *ErrorMsg += "' and '";
133  *ErrorMsg += F2P[0];
134  *ErrorMsg += "'";
135  }
136  return true;
137  }
138 
139  // Check to see if these are inside the absolute tolerance
140  if (AbsTolerance < std::abs(V1-V2)) {
141  // Nope, check the relative tolerance...
142  double Diff;
143  if (V2)
144  Diff = std::abs(V1/V2 - 1.0);
145  else if (V1)
146  Diff = std::abs(V2/V1 - 1.0);
147  else
148  Diff = 0; // Both zero.
149  if (Diff > RelTolerance) {
150  if (ErrorMsg) {
151  raw_string_ostream(*ErrorMsg)
152  << "Compared: " << V1 << " and " << V2 << '\n'
153  << "abs. diff = " << std::abs(V1-V2) << " rel.diff = " << Diff << '\n'
154  << "Out of tolerance: rel/abs: " << RelTolerance << '/'
155  << AbsTolerance;
156  }
157  return true;
158  }
159  }
160 
161  // Otherwise, advance our read pointers to the end of the numbers.
162  F1P = F1NumEnd; F2P = F2NumEnd;
163  return false;
164 }
165 
166 /// DiffFilesWithTolerance - Compare the two files specified, returning 0 if the
167 /// files match, 1 if they are different, and 2 if there is a file error. This
168 /// function differs from DiffFiles in that you can specify an absolete and
169 /// relative FP error that is allowed to exist. If you specify a string to fill
170 /// in for the error option, it will set the string to an error message if an
171 /// error occurs, allowing the caller to distinguish between a failed diff and a
172 /// file system error.
173 ///
175  StringRef NameB,
176  double AbsTol, double RelTol,
177  std::string *Error) {
178  // Now its safe to mmap the files into memory because both files
179  // have a non-zero size.
181  if (error_code ec = MemoryBuffer::getFile(NameA, F1)) {
182  if (Error)
183  *Error = ec.message();
184  return 2;
185  }
187  if (error_code ec = MemoryBuffer::getFile(NameB, F2)) {
188  if (Error)
189  *Error = ec.message();
190  return 2;
191  }
192 
193  // Okay, now that we opened the files, scan them for the first difference.
194  const char *File1Start = F1->getBufferStart();
195  const char *File2Start = F2->getBufferStart();
196  const char *File1End = F1->getBufferEnd();
197  const char *File2End = F2->getBufferEnd();
198  const char *F1P = File1Start;
199  const char *F2P = File2Start;
200  uint64_t A_size = F1->getBufferSize();
201  uint64_t B_size = F2->getBufferSize();
202 
203  // Are the buffers identical? Common case: Handle this efficiently.
204  if (A_size == B_size &&
205  std::memcmp(File1Start, File2Start, A_size) == 0)
206  return 0;
207 
208  // Otherwise, we are done a tolerances are set.
209  if (AbsTol == 0 && RelTol == 0) {
210  if (Error)
211  *Error = "Files differ without tolerance allowance";
212  return 1; // Files different!
213  }
214 
215  bool CompareFailed = false;
216  while (1) {
217  // Scan for the end of file or next difference.
218  while (F1P < File1End && F2P < File2End && *F1P == *F2P)
219  ++F1P, ++F2P;
220 
221  if (F1P >= File1End || F2P >= File2End) break;
222 
223  // Okay, we must have found a difference. Backup to the start of the
224  // current number each stream is at so that we can compare from the
225  // beginning.
226  F1P = BackupNumber(F1P, File1Start);
227  F2P = BackupNumber(F2P, File2Start);
228 
229  // Now that we are at the start of the numbers, compare them, exiting if
230  // they don't match.
231  if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) {
232  CompareFailed = true;
233  break;
234  }
235  }
236 
237  // Okay, we reached the end of file. If both files are at the end, we
238  // succeeded.
239  bool F1AtEnd = F1P >= File1End;
240  bool F2AtEnd = F2P >= File2End;
241  if (!CompareFailed && (!F1AtEnd || !F2AtEnd)) {
242  // Else, we might have run off the end due to a number: backup and retry.
243  if (F1AtEnd && isNumberChar(F1P[-1])) --F1P;
244  if (F2AtEnd && isNumberChar(F2P[-1])) --F2P;
245  F1P = BackupNumber(F1P, File1Start);
246  F2P = BackupNumber(F2P, File2Start);
247 
248  // Now that we are at the start of the numbers, compare them, exiting if
249  // they don't match.
250  if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error))
251  CompareFailed = true;
252 
253  // If we found the end, we succeeded.
254  if (F1P < File1End || F2P < File2End)
255  CompareFailed = true;
256  }
257 
258  return CompareFailed;
259 }
const char * getBufferStart() const
Definition: MemoryBuffer.h:51
int abs(int j);
static const char * BackupNumber(const char *Pos, const char *FirstChar)
double strtod(const char *nptr, char **endptr);
static const char * EndOfNumber(const char *Pos)
static bool CompareNumbers(const char *&F1P, const char *&F2P, const char *F1End, const char *F2End, double AbsTolerance, double RelTolerance, std::string *ErrorMsg)
CompareNumbers - compare two numbers, returning true if they are different.
int memcmp(const void *s1, const void *s2, size_t n);
static bool isNumberChar(char C)
static bool isSignedChar(char C)
static error_code getFile(Twine Filename, OwningPtr< MemoryBuffer > &result, int64_t FileSize=-1, bool RequiresNullTerminator=true)
size_t getBufferSize() const
Definition: MemoryBuffer.h:53
const char * getBufferEnd() const
Definition: MemoryBuffer.h:52
int DiffFilesWithTolerance(StringRef FileA, StringRef FileB, double AbsTol, double RelTol, std::string *Error=0)
static bool isExponentChar(char C)