LLVM  10.0.0svn
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/ScopeExit.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/Support/Error.h"
18 #include "llvm/Support/ErrorOr.h"
20 #include "llvm/Support/Path.h"
22 #include <cctype>
23 #include <cmath>
24 #include <cstdint>
25 #include <cstdlib>
26 #include <cstring>
27 #include <memory>
28 #include <system_error>
29 
30 using namespace llvm;
31 
32 static bool isSignedChar(char C) {
33  return (C == '+' || C == '-');
34 }
35 
36 static bool isExponentChar(char C) {
37  switch (C) {
38  case 'D': // Strange exponential notation.
39  case 'd': // Strange exponential notation.
40  case 'e':
41  case 'E': return true;
42  default: return false;
43  }
44 }
45 
46 static bool isNumberChar(char C) {
47  switch (C) {
48  case '0': case '1': case '2': case '3': case '4':
49  case '5': case '6': case '7': case '8': case '9':
50  case '.': return true;
51  default: return isSignedChar(C) || isExponentChar(C);
52  }
53 }
54 
55 static const char *BackupNumber(const char *Pos, const char *FirstChar) {
56  // If we didn't stop in the middle of a number, don't backup.
57  if (!isNumberChar(*Pos)) return Pos;
58 
59  // Otherwise, return to the start of the number.
60  bool HasPeriod = false;
61  while (Pos > FirstChar && isNumberChar(Pos[-1])) {
62  // Backup over at most one period.
63  if (Pos[-1] == '.') {
64  if (HasPeriod)
65  break;
66  HasPeriod = true;
67  }
68 
69  --Pos;
70  if (Pos > FirstChar && isSignedChar(Pos[0]) && !isExponentChar(Pos[-1]))
71  break;
72  }
73  return Pos;
74 }
75 
76 /// EndOfNumber - Return the first character that is not part of the specified
77 /// number. This assumes that the buffer is null terminated, so it won't fall
78 /// off the end.
79 static const char *EndOfNumber(const char *Pos) {
80  while (isNumberChar(*Pos))
81  ++Pos;
82  return Pos;
83 }
84 
85 /// CompareNumbers - compare two numbers, returning true if they are different.
86 static bool CompareNumbers(const char *&F1P, const char *&F2P,
87  const char *F1End, const char *F2End,
88  double AbsTolerance, double RelTolerance,
89  std::string *ErrorMsg) {
90  const char *F1NumEnd, *F2NumEnd;
91  double V1 = 0.0, V2 = 0.0;
92 
93  // If one of the positions is at a space and the other isn't, chomp up 'til
94  // the end of the space.
95  while (isspace(static_cast<unsigned char>(*F1P)) && F1P != F1End)
96  ++F1P;
97  while (isspace(static_cast<unsigned char>(*F2P)) && F2P != F2End)
98  ++F2P;
99 
100  // If we stop on numbers, compare their difference.
101  if (!isNumberChar(*F1P) || !isNumberChar(*F2P)) {
102  // The diff failed.
103  F1NumEnd = F1P;
104  F2NumEnd = F2P;
105  } else {
106  // Note that some ugliness is built into this to permit support for numbers
107  // that use "D" or "d" as their exponential marker, e.g. "1.234D45". This
108  // occurs in 200.sixtrack in spec2k.
109  V1 = strtod(F1P, const_cast<char**>(&F1NumEnd));
110  V2 = strtod(F2P, const_cast<char**>(&F2NumEnd));
111 
112  if (*F1NumEnd == 'D' || *F1NumEnd == 'd') {
113  // Copy string into tmp buffer to replace the 'D' with an 'e'.
114  SmallString<200> StrTmp(F1P, EndOfNumber(F1NumEnd)+1);
115  // Strange exponential notation!
116  StrTmp[static_cast<unsigned>(F1NumEnd-F1P)] = 'e';
117 
118  V1 = strtod(&StrTmp[0], const_cast<char**>(&F1NumEnd));
119  F1NumEnd = F1P + (F1NumEnd-&StrTmp[0]);
120  }
121 
122  if (*F2NumEnd == 'D' || *F2NumEnd == 'd') {
123  // Copy string into tmp buffer to replace the 'D' with an 'e'.
124  SmallString<200> StrTmp(F2P, EndOfNumber(F2NumEnd)+1);
125  // Strange exponential notation!
126  StrTmp[static_cast<unsigned>(F2NumEnd-F2P)] = 'e';
127 
128  V2 = strtod(&StrTmp[0], const_cast<char**>(&F2NumEnd));
129  F2NumEnd = F2P + (F2NumEnd-&StrTmp[0]);
130  }
131  }
132 
133  if (F1NumEnd == F1P || F2NumEnd == F2P) {
134  if (ErrorMsg) {
135  *ErrorMsg = "FP Comparison failed, not a numeric difference between '";
136  *ErrorMsg += F1P[0];
137  *ErrorMsg += "' and '";
138  *ErrorMsg += F2P[0];
139  *ErrorMsg += "'";
140  }
141  return true;
142  }
143 
144  // Check to see if these are inside the absolute tolerance
145  if (AbsTolerance < std::abs(V1-V2)) {
146  // Nope, check the relative tolerance...
147  double Diff;
148  if (V2)
149  Diff = std::abs(V1/V2 - 1.0);
150  else if (V1)
151  Diff = std::abs(V2/V1 - 1.0);
152  else
153  Diff = 0; // Both zero.
154  if (Diff > RelTolerance) {
155  if (ErrorMsg) {
156  raw_string_ostream(*ErrorMsg)
157  << "Compared: " << V1 << " and " << V2 << '\n'
158  << "abs. diff = " << std::abs(V1-V2) << " rel.diff = " << Diff << '\n'
159  << "Out of tolerance: rel/abs: " << RelTolerance << '/'
160  << AbsTolerance;
161  }
162  return true;
163  }
164  }
165 
166  // Otherwise, advance our read pointers to the end of the numbers.
167  F1P = F1NumEnd; F2P = F2NumEnd;
168  return false;
169 }
170 
171 /// DiffFilesWithTolerance - Compare the two files specified, returning 0 if the
172 /// files match, 1 if they are different, and 2 if there is a file error. This
173 /// function differs from DiffFiles in that you can specify an absolete and
174 /// relative FP error that is allowed to exist. If you specify a string to fill
175 /// in for the error option, it will set the string to an error message if an
176 /// error occurs, allowing the caller to distinguish between a failed diff and a
177 /// file system error.
178 ///
180  StringRef NameB,
181  double AbsTol, double RelTol,
182  std::string *Error) {
183  // Now its safe to mmap the files into memory because both files
184  // have a non-zero size.
186  if (std::error_code EC = F1OrErr.getError()) {
187  if (Error)
188  *Error = EC.message();
189  return 2;
190  }
191  MemoryBuffer &F1 = *F1OrErr.get();
192 
194  if (std::error_code EC = F2OrErr.getError()) {
195  if (Error)
196  *Error = EC.message();
197  return 2;
198  }
199  MemoryBuffer &F2 = *F2OrErr.get();
200 
201  // Okay, now that we opened the files, scan them for the first difference.
202  const char *File1Start = F1.getBufferStart();
203  const char *File2Start = F2.getBufferStart();
204  const char *File1End = F1.getBufferEnd();
205  const char *File2End = F2.getBufferEnd();
206  const char *F1P = File1Start;
207  const char *F2P = File2Start;
208  uint64_t A_size = F1.getBufferSize();
209  uint64_t B_size = F2.getBufferSize();
210 
211  // Are the buffers identical? Common case: Handle this efficiently.
212  if (A_size == B_size &&
213  std::memcmp(File1Start, File2Start, A_size) == 0)
214  return 0;
215 
216  // Otherwise, we are done a tolerances are set.
217  if (AbsTol == 0 && RelTol == 0) {
218  if (Error)
219  *Error = "Files differ without tolerance allowance";
220  return 1; // Files different!
221  }
222 
223  bool CompareFailed = false;
224  while (true) {
225  // Scan for the end of file or next difference.
226  while (F1P < File1End && F2P < File2End && *F1P == *F2P) {
227  ++F1P;
228  ++F2P;
229  }
230 
231  if (F1P >= File1End || F2P >= File2End) break;
232 
233  // Okay, we must have found a difference. Backup to the start of the
234  // current number each stream is at so that we can compare from the
235  // beginning.
236  F1P = BackupNumber(F1P, File1Start);
237  F2P = BackupNumber(F2P, File2Start);
238 
239  // Now that we are at the start of the numbers, compare them, exiting if
240  // they don't match.
241  if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error)) {
242  CompareFailed = true;
243  break;
244  }
245  }
246 
247  // Okay, we reached the end of file. If both files are at the end, we
248  // succeeded.
249  bool F1AtEnd = F1P >= File1End;
250  bool F2AtEnd = F2P >= File2End;
251  if (!CompareFailed && (!F1AtEnd || !F2AtEnd)) {
252  // Else, we might have run off the end due to a number: backup and retry.
253  if (F1AtEnd && isNumberChar(F1P[-1])) --F1P;
254  if (F2AtEnd && isNumberChar(F2P[-1])) --F2P;
255  F1P = BackupNumber(F1P, File1Start);
256  F2P = BackupNumber(F2P, File2Start);
257 
258  // Now that we are at the start of the numbers, compare them, exiting if
259  // they don't match.
260  if (CompareNumbers(F1P, F2P, File1End, File2End, AbsTol, RelTol, Error))
261  CompareFailed = true;
262 
263  // If we found the end, we succeeded.
264  if (F1P < File1End || F2P < File2End)
265  CompareFailed = true;
266  }
267 
268  return CompareFailed;
269 }
270 
272  OS << "atomic_write_error: ";
273  switch (Error) {
275  OS << "failed_to_create_uniq_file";
276  return;
278  OS << "output_stream_error";
279  return;
281  OS << "failed_to_rename_temp_file";
282  return;
283  }
284  llvm_unreachable("unknown atomic_write_error value in "
285  "failed_to_rename_temp_file::log()");
286 }
287 
289  StringRef FinalPath, StringRef Buffer) {
290  return writeFileAtomically(TempPathModel, FinalPath,
291  [&Buffer](llvm::raw_ostream &OS) {
292  OS.write(Buffer.data(), Buffer.size());
293  return llvm::Error::success();
294  });
295 }
296 
298  StringRef TempPathModel, StringRef FinalPath,
300  SmallString<128> GeneratedUniqPath;
301  int TempFD;
302  if (sys::fs::createUniqueFile(TempPathModel.str(), TempFD,
303  GeneratedUniqPath)) {
304  return llvm::make_error<AtomicFileWriteError>(
306  }
307  llvm::FileRemover RemoveTmpFileOnFail(GeneratedUniqPath);
308 
309  raw_fd_ostream OS(TempFD, /*shouldClose=*/true);
310  if (llvm::Error Err = Writer(OS)) {
311  return Err;
312  }
313 
314  OS.close();
315  if (OS.has_error()) {
316  OS.clear_error();
317  return llvm::make_error<AtomicFileWriteError>(
319  }
320 
321  if (const std::error_code Error =
322  sys::fs::rename(/*from=*/GeneratedUniqPath.c_str(),
323  /*to=*/FinalPath.str().c_str())) {
324  return llvm::make_error<AtomicFileWriteError>(
326  }
327 
328  RemoveTmpFileOnFail.releaseFile();
329  return Error::success();
330 }
331 
uint64_t CallInst * C
Represents either an error or a value T.
Definition: ErrorOr.h:56
LLVM_NODISCARD std::string str() const
str - Get the contents as an std::string.
Definition: StringRef.h:232
This class represents lattice values for constants.
Definition: AllocatorList.h:23
std::error_code createUniqueFile(const Twine &Model, int &ResultFD, SmallVectorImpl< char > &ResultPath, unsigned Mode=all_read|all_write)
Create a uniquely named file.
Definition: Path.cpp:767
static const char * BackupNumber(const char *Pos, const char *FirstChar)
size_t getBufferSize() const
Definition: MemoryBuffer.h:61
void log(raw_ostream &OS) const override
Print an error message to an output stream.
FileRemover - This class is a simple object meant to be stack allocated.
Definition: FileUtilities.h:42
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...
LLVM_NODISCARD size_t size() const
size - Get the string size.
Definition: StringRef.h:144
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)
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
bool has_error() const
Return the value of the flag in this raw_fd_ostream indicating whether an output error has been encou...
Definition: raw_ostream.h:472
raw_ostream & write(unsigned char C)
std::error_code rename(const Twine &from, const Twine &to)
Rename from to to.
static ErrorSuccess success()
Create a success value.
Definition: Error.h:326
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
A raw_ostream that writes to a file descriptor.
Definition: raw_ostream.h:384
Merge contiguous icmps into a memcmp
Definition: MergeICmps.cpp:927
const char * c_str()
Definition: SmallString.h:269
APFloat abs(APFloat X)
Returns the absolute value of the argument.
Definition: APFloat.h:1228
const char * getBufferStart() const
Definition: MemoryBuffer.h:59
void close()
Manually flush the stream and close the file.
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.
LLVM_NODISCARD const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:136
llvm::Error writeFileAtomically(StringRef TempPathModel, StringRef FinalPath, StringRef Buffer)
Creates a unique file with name according to the given TempPathModel, writes content of Buffer to the...
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:503
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
print Print MemDeps of function
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
void clear_error()
Set the flag read by has_error() to false.
Definition: raw_ostream.h:483