LLVM  9.0.0svn
FileUtilities.cpp
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1 //===- Support/FileUtilities.cpp - File System Utilities ------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements a family of utility functions which are useful for doing
10 // various things with files.
11 //
12 //===----------------------------------------------------------------------===//
13 
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/Support/ErrorOr.h"
19 #include <cctype>
20 #include <cmath>
21 #include <cstdint>
22 #include <cstdlib>
23 #include <cstring>
24 #include <memory>
25 #include <system_error>
26 
27 using namespace llvm;
28 
29 static bool isSignedChar(char C) {
30  return (C == '+' || C == '-');
31 }
32 
33 static bool isExponentChar(char C) {
34  switch (C) {
35  case 'D': // Strange exponential notation.
36  case 'd': // Strange exponential notation.
37  case 'e':
38  case 'E': return true;
39  default: return false;
40  }
41 }
42 
43 static bool isNumberChar(char C) {
44  switch (C) {
45  case '0': case '1': case '2': case '3': case '4':
46  case '5': case '6': case '7': case '8': case '9':
47  case '.': return true;
48  default: return isSignedChar(C) || isExponentChar(C);
49  }
50 }
51 
52 static const char *BackupNumber(const char *Pos, const char *FirstChar) {
53  // If we didn't stop in the middle of a number, don't backup.
54  if (!isNumberChar(*Pos)) return Pos;
55 
56  // Otherwise, return to the start of the number.
57  bool HasPeriod = false;
58  while (Pos > FirstChar && isNumberChar(Pos[-1])) {
59  // Backup over at most one period.
60  if (Pos[-1] == '.') {
61  if (HasPeriod)
62  break;
63  HasPeriod = true;
64  }
65 
66  --Pos;
67  if (Pos > FirstChar && isSignedChar(Pos[0]) && !isExponentChar(Pos[-1]))
68  break;
69  }
70  return Pos;
71 }
72 
73 /// EndOfNumber - Return the first character that is not part of the specified
74 /// number. This assumes that the buffer is null terminated, so it won't fall
75 /// off the end.
76 static const char *EndOfNumber(const char *Pos) {
77  while (isNumberChar(*Pos))
78  ++Pos;
79  return Pos;
80 }
81 
82 /// CompareNumbers - compare two numbers, returning true if they are different.
83 static bool CompareNumbers(const char *&F1P, const char *&F2P,
84  const char *F1End, const char *F2End,
85  double AbsTolerance, double RelTolerance,
86  std::string *ErrorMsg) {
87  const char *F1NumEnd, *F2NumEnd;
88  double V1 = 0.0, V2 = 0.0;
89 
90  // If one of the positions is at a space and the other isn't, chomp up 'til
91  // the end of the space.
92  while (isspace(static_cast<unsigned char>(*F1P)) && F1P != F1End)
93  ++F1P;
94  while (isspace(static_cast<unsigned char>(*F2P)) && F2P != F2End)
95  ++F2P;
96 
97  // If we stop on numbers, compare their difference.
98  if (!isNumberChar(*F1P) || !isNumberChar(*F2P)) {
99  // The diff failed.
100  F1NumEnd = F1P;
101  F2NumEnd = F2P;
102  } else {
103  // Note that some ugliness is built into this to permit support for numbers
104  // that use "D" or "d" as their exponential marker, e.g. "1.234D45". This
105  // occurs in 200.sixtrack in spec2k.
106  V1 = strtod(F1P, const_cast<char**>(&F1NumEnd));
107  V2 = strtod(F2P, const_cast<char**>(&F2NumEnd));
108 
109  if (*F1NumEnd == 'D' || *F1NumEnd == 'd') {
110  // Copy string into tmp buffer to replace the 'D' with an 'e'.
111  SmallString<200> StrTmp(F1P, EndOfNumber(F1NumEnd)+1);
112  // Strange exponential notation!
113  StrTmp[static_cast<unsigned>(F1NumEnd-F1P)] = 'e';
114 
115  V1 = strtod(&StrTmp[0], const_cast<char**>(&F1NumEnd));
116  F1NumEnd = F1P + (F1NumEnd-&StrTmp[0]);
117  }
118 
119  if (*F2NumEnd == 'D' || *F2NumEnd == 'd') {
120  // Copy string into tmp buffer to replace the 'D' with an 'e'.
121  SmallString<200> StrTmp(F2P, EndOfNumber(F2NumEnd)+1);
122  // Strange exponential notation!
123  StrTmp[static_cast<unsigned>(F2NumEnd-F2P)] = 'e';
124 
125  V2 = strtod(&StrTmp[0], const_cast<char**>(&F2NumEnd));
126  F2NumEnd = F2P + (F2NumEnd-&StrTmp[0]);
127  }
128  }
129 
130  if (F1NumEnd == F1P || F2NumEnd == F2P) {
131  if (ErrorMsg) {
132  *ErrorMsg = "FP Comparison failed, not a numeric difference between '";
133  *ErrorMsg += F1P[0];
134  *ErrorMsg += "' and '";
135  *ErrorMsg += F2P[0];
136  *ErrorMsg += "'";
137  }
138  return true;
139  }
140 
141  // Check to see if these are inside the absolute tolerance
142  if (AbsTolerance < std::abs(V1-V2)) {
143  // Nope, check the relative tolerance...
144  double Diff;
145  if (V2)
146  Diff = std::abs(V1/V2 - 1.0);
147  else if (V1)
148  Diff = std::abs(V2/V1 - 1.0);
149  else
150  Diff = 0; // Both zero.
151  if (Diff > RelTolerance) {
152  if (ErrorMsg) {
153  raw_string_ostream(*ErrorMsg)
154  << "Compared: " << V1 << " and " << V2 << '\n'
155  << "abs. diff = " << std::abs(V1-V2) << " rel.diff = " << Diff << '\n'
156  << "Out of tolerance: rel/abs: " << RelTolerance << '/'
157  << AbsTolerance;
158  }
159  return true;
160  }
161  }
162 
163  // Otherwise, advance our read pointers to the end of the numbers.
164  F1P = F1NumEnd; F2P = F2NumEnd;
165  return false;
166 }
167 
168 /// DiffFilesWithTolerance - Compare the two files specified, returning 0 if the
169 /// files match, 1 if they are different, and 2 if there is a file error. This
170 /// function differs from DiffFiles in that you can specify an absolete and
171 /// relative FP error that is allowed to exist. If you specify a string to fill
172 /// in for the error option, it will set the string to an error message if an
173 /// error occurs, allowing the caller to distinguish between a failed diff and a
174 /// file system error.
175 ///
177  StringRef NameB,
178  double AbsTol, double RelTol,
179  std::string *Error) {
180  // Now its safe to mmap the files into memory because both files
181  // have a non-zero size.
183  if (std::error_code EC = F1OrErr.getError()) {
184  if (Error)
185  *Error = EC.message();
186  return 2;
187  }
188  MemoryBuffer &F1 = *F1OrErr.get();
189 
191  if (std::error_code EC = F2OrErr.getError()) {
192  if (Error)
193  *Error = EC.message();
194  return 2;
195  }
196  MemoryBuffer &F2 = *F2OrErr.get();
197 
198  // Okay, now that we opened the files, scan them for the first difference.
199  const char *File1Start = F1.getBufferStart();
200  const char *File2Start = F2.getBufferStart();
201  const char *File1End = F1.getBufferEnd();
202  const char *File2End = F2.getBufferEnd();
203  const char *F1P = File1Start;
204  const char *F2P = File2Start;
205  uint64_t A_size = F1.getBufferSize();
206  uint64_t B_size = F2.getBufferSize();
207 
208  // Are the buffers identical? Common case: Handle this efficiently.
209  if (A_size == B_size &&
210  std::memcmp(File1Start, File2Start, A_size) == 0)
211  return 0;
212 
213  // Otherwise, we are done a tolerances are set.
214  if (AbsTol == 0 && RelTol == 0) {
215  if (Error)
216  *Error = "Files differ without tolerance allowance";
217  return 1; // Files different!
218  }
219 
220  bool CompareFailed = false;
221  while (true) {
222  // Scan for the end of file or next difference.
223  while (F1P < File1End && F2P < File2End && *F1P == *F2P) {
224  ++F1P;
225  ++F2P;
226  }
227 
228  if (F1P >= File1End || F2P >= File2End) break;
229 
230  // Okay, we must have found a difference. Backup to the start of the
231  // current number each stream is at so that we can compare from the
232  // beginning.
233  F1P = BackupNumber(F1P, File1Start);
234  F2P = BackupNumber(F2P, File2Start);
235 
236  // Now that we are at the start of the numbers, compare them, exiting if
237  // they don't match.
238  if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) {
239  CompareFailed = true;
240  break;
241  }
242  }
243 
244  // Okay, we reached the end of file. If both files are at the end, we
245  // succeeded.
246  bool F1AtEnd = F1P >= File1End;
247  bool F2AtEnd = F2P >= File2End;
248  if (!CompareFailed && (!F1AtEnd || !F2AtEnd)) {
249  // Else, we might have run off the end due to a number: backup and retry.
250  if (F1AtEnd && isNumberChar(F1P[-1])) --F1P;
251  if (F2AtEnd && isNumberChar(F2P[-1])) --F2P;
252  F1P = BackupNumber(F1P, File1Start);
253  F2P = BackupNumber(F2P, File2Start);
254 
255  // Now that we are at the start of the numbers, compare them, exiting if
256  // they don't match.
257  if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error))
258  CompareFailed = true;
259 
260  // If we found the end, we succeeded.
261  if (F1P < File1End || F2P < File2End)
262  CompareFailed = true;
263  }
264 
265  return CompareFailed;
266 }
uint64_t CallInst * C
Represents either an error or a value T.
Definition: ErrorOr.h:56
This class represents lattice values for constants.
Definition: AllocatorList.h:23
static const char * BackupNumber(const char *Pos, const char *FirstChar)
size_t getBufferSize() const
Definition: MemoryBuffer.h:61
static const char * EndOfNumber(const char *Pos)
EndOfNumber - Return the first character that is not part of the specified number.
int DiffFilesWithTolerance(StringRef FileA, StringRef FileB, double AbsTol, double RelTol, std::string *Error=nullptr)
DiffFilesWithTolerance - Compare the two files specified, returning 0 if the files match...
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:25
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.
std::error_code getError() const
Definition: ErrorOr.h:159
static bool isNumberChar(char C)
static bool isSignedChar(char C)
This interface provides simple read-only access to a block of memory, and provides simple methods for...
Definition: MemoryBuffer.h:41
const char * getBufferEnd() const
Definition: MemoryBuffer.h:60
Merge contiguous icmps into a memcmp
Definition: MergeICmps.cpp:881
APFloat abs(APFloat X)
Returns the absolute value of the argument.
Definition: APFloat.h:1212
const char * getBufferStart() const
Definition: MemoryBuffer.h:59
Provides ErrorOr<T> smart pointer.
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFile(const Twine &Filename, int64_t FileSize=-1, bool RequiresNullTerminator=true, bool IsVolatile=false)
Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null.
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:482
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
static bool isExponentChar(char C)
reference get()
Definition: ErrorOr.h:156