1 //===- Support/FileUtilities.cpp - File System Utilities ------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a family of utility functions which are useful for doing
11 // various things with files.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Support/FileUtilities.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/Support/MemoryBuffer.h"
18 #include "llvm/Support/Path.h"
19 #include "llvm/Support/raw_ostream.h"
23 #include <system_error>
26 static bool isSignedChar(char C) {
27 return (C == '+' || C == '-');
30 static bool isExponentChar(char C) {
32 case 'D': // Strange exponential notation.
33 case 'd': // Strange exponential notation.
35 case 'E': return true;
36 default: return false;
40 static bool isNumberChar(char C) {
42 case '0': case '1': case '2': case '3': case '4':
43 case '5': case '6': case '7': case '8': case '9':
44 case '.': return true;
45 default: return isSignedChar(C) || isExponentChar(C);
49 static const char *BackupNumber(const char *Pos, const char *FirstChar) {
50 // If we didn't stop in the middle of a number, don't backup.
51 if (!isNumberChar(*Pos)) return Pos;
53 // Otherwise, return to the start of the number.
54 bool HasPeriod = false;
55 while (Pos > FirstChar && isNumberChar(Pos[-1])) {
56 // Backup over at most one period.
64 if (Pos > FirstChar && isSignedChar(Pos[0]) && !isExponentChar(Pos[-1]))
70 /// EndOfNumber - Return the first character that is not part of the specified
71 /// number. This assumes that the buffer is null terminated, so it won't fall
73 static const char *EndOfNumber(const char *Pos) {
74 while (isNumberChar(*Pos))
79 /// CompareNumbers - compare two numbers, returning true if they are different.
80 static bool CompareNumbers(const char *&F1P, const char *&F2P,
81 const char *F1End, const char *F2End,
82 double AbsTolerance, double RelTolerance,
83 std::string *ErrorMsg) {
84 const char *F1NumEnd, *F2NumEnd;
85 double V1 = 0.0, V2 = 0.0;
87 // If one of the positions is at a space and the other isn't, chomp up 'til
88 // the end of the space.
89 while (isspace(static_cast<unsigned char>(*F1P)) && F1P != F1End)
91 while (isspace(static_cast<unsigned char>(*F2P)) && F2P != F2End)
94 // If we stop on numbers, compare their difference.
95 if (!isNumberChar(*F1P) || !isNumberChar(*F2P)) {
100 // Note that some ugliness is built into this to permit support for numbers
101 // that use "D" or "d" as their exponential marker, e.g. "1.234D45". This
102 // occurs in 200.sixtrack in spec2k.
103 V1 = strtod(F1P, const_cast<char**>(&F1NumEnd));
104 V2 = strtod(F2P, const_cast<char**>(&F2NumEnd));
106 if (*F1NumEnd == 'D' || *F1NumEnd == 'd') {
107 // Copy string into tmp buffer to replace the 'D' with an 'e'.
108 SmallString<200> StrTmp(F1P, EndOfNumber(F1NumEnd)+1);
109 // Strange exponential notation!
110 StrTmp[static_cast<unsigned>(F1NumEnd-F1P)] = 'e';
112 V1 = strtod(&StrTmp[0], const_cast<char**>(&F1NumEnd));
113 F1NumEnd = F1P + (F1NumEnd-&StrTmp[0]);
116 if (*F2NumEnd == 'D' || *F2NumEnd == 'd') {
117 // Copy string into tmp buffer to replace the 'D' with an 'e'.
118 SmallString<200> StrTmp(F2P, EndOfNumber(F2NumEnd)+1);
119 // Strange exponential notation!
120 StrTmp[static_cast<unsigned>(F2NumEnd-F2P)] = 'e';
122 V2 = strtod(&StrTmp[0], const_cast<char**>(&F2NumEnd));
123 F2NumEnd = F2P + (F2NumEnd-&StrTmp[0]);
127 if (F1NumEnd == F1P || F2NumEnd == F2P) {
129 *ErrorMsg = "FP Comparison failed, not a numeric difference between '";
131 *ErrorMsg += "' and '";
138 // Check to see if these are inside the absolute tolerance
139 if (AbsTolerance < std::abs(V1-V2)) {
140 // Nope, check the relative tolerance...
143 Diff = std::abs(V1/V2 - 1.0);
145 Diff = std::abs(V2/V1 - 1.0);
147 Diff = 0; // Both zero.
148 if (Diff > RelTolerance) {
150 raw_string_ostream(*ErrorMsg)
151 << "Compared: " << V1 << " and " << V2 << '\n'
152 << "abs. diff = " << std::abs(V1-V2) << " rel.diff = " << Diff << '\n'
153 << "Out of tolerance: rel/abs: " << RelTolerance << '/'
160 // Otherwise, advance our read pointers to the end of the numbers.
161 F1P = F1NumEnd; F2P = F2NumEnd;
165 /// DiffFilesWithTolerance - Compare the two files specified, returning 0 if the
166 /// files match, 1 if they are different, and 2 if there is a file error. This
167 /// function differs from DiffFiles in that you can specify an absolete and
168 /// relative FP error that is allowed to exist. If you specify a string to fill
169 /// in for the error option, it will set the string to an error message if an
170 /// error occurs, allowing the caller to distinguish between a failed diff and a
171 /// file system error.
173 int llvm::DiffFilesWithTolerance(StringRef NameA,
175 double AbsTol, double RelTol,
176 std::string *Error) {
177 // Now its safe to mmap the files into memory because both files
178 // have a non-zero size.
179 ErrorOr<std::unique_ptr<MemoryBuffer>> F1OrErr = MemoryBuffer::getFile(NameA);
180 if (std::error_code EC = F1OrErr.getError()) {
182 *Error = EC.message();
185 MemoryBuffer &F1 = *F1OrErr.get();
187 ErrorOr<std::unique_ptr<MemoryBuffer>> F2OrErr = MemoryBuffer::getFile(NameB);
188 if (std::error_code EC = F2OrErr.getError()) {
190 *Error = EC.message();
193 MemoryBuffer &F2 = *F2OrErr.get();
195 // Okay, now that we opened the files, scan them for the first difference.
196 const char *File1Start = F1.getBufferStart();
197 const char *File2Start = F2.getBufferStart();
198 const char *File1End = F1.getBufferEnd();
199 const char *File2End = F2.getBufferEnd();
200 const char *F1P = File1Start;
201 const char *F2P = File2Start;
202 uint64_t A_size = F1.getBufferSize();
203 uint64_t B_size = F2.getBufferSize();
205 // Are the buffers identical? Common case: Handle this efficiently.
206 if (A_size == B_size &&
207 std::memcmp(File1Start, File2Start, A_size) == 0)
210 // Otherwise, we are done a tolerances are set.
211 if (AbsTol == 0 && RelTol == 0) {
213 *Error = "Files differ without tolerance allowance";
214 return 1; // Files different!
217 bool CompareFailed = false;
219 // Scan for the end of file or next difference.
220 while (F1P < File1End && F2P < File2End && *F1P == *F2P)
223 if (F1P >= File1End || F2P >= File2End) break;
225 // Okay, we must have found a difference. Backup to the start of the
226 // current number each stream is at so that we can compare from the
228 F1P = BackupNumber(F1P, File1Start);
229 F2P = BackupNumber(F2P, File2Start);
231 // Now that we are at the start of the numbers, compare them, exiting if
233 if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) {
234 CompareFailed = true;
239 // Okay, we reached the end of file. If both files are at the end, we
241 bool F1AtEnd = F1P >= File1End;
242 bool F2AtEnd = F2P >= File2End;
243 if (!CompareFailed && (!F1AtEnd || !F2AtEnd)) {
244 // Else, we might have run off the end due to a number: backup and retry.
245 if (F1AtEnd && isNumberChar(F1P[-1])) --F1P;
246 if (F2AtEnd && isNumberChar(F2P[-1])) --F2P;
247 F1P = BackupNumber(F1P, File1Start);
248 F2P = BackupNumber(F2P, File2Start);
250 // Now that we are at the start of the numbers, compare them, exiting if
252 if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error))
253 CompareFailed = true;
255 // If we found the end, we succeeded.
256 if (F1P < File1End || F2P < File2End)
257 CompareFailed = true;
260 return CompareFailed;