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llvm-mirror/lib/Support/FileUtilities.cpp
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

267 lines
8.7 KiB
C++

//===- Support/FileUtilities.cpp - File System Utilities ------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements a family of utility functions which are useful for doing
// various things with files.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/FileUtilities.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <cctype>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <memory>
#include <system_error>
using namespace llvm;
static bool isSignedChar(char C) {
return (C == '+' || C == '-');
}
static bool isExponentChar(char C) {
switch (C) {
case 'D': // Strange exponential notation.
case 'd': // Strange exponential notation.
case 'e':
case 'E': return true;
default: return false;
}
}
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 '.': return true;
default: return isSignedChar(C) || isExponentChar(C);
}
}
static const char *BackupNumber(const char *Pos, const 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.
bool HasPeriod = false;
while (Pos > FirstChar && isNumberChar(Pos[-1])) {
// Backup over at most one period.
if (Pos[-1] == '.') {
if (HasPeriod)
break;
HasPeriod = true;
}
--Pos;
if (Pos > FirstChar && isSignedChar(Pos[0]) && !isExponentChar(Pos[-1]))
break;
}
return Pos;
}
/// EndOfNumber - Return the first character that is not part of the specified
/// number. This assumes that the buffer is null terminated, so it won't fall
/// off the end.
static const char *EndOfNumber(const char *Pos) {
while (isNumberChar(*Pos))
++Pos;
return Pos;
}
/// CompareNumbers - compare two numbers, returning true if they are different.
static bool CompareNumbers(const char *&F1P, const char *&F2P,
const char *F1End, const char *F2End,
double AbsTolerance, double RelTolerance,
std::string *ErrorMsg) {
const 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(static_cast<unsigned char>(*F1P)) && F1P != F1End)
++F1P;
while (isspace(static_cast<unsigned char>(*F2P)) && F2P != F2End)
++F2P;
// If we stop on numbers, compare their difference.
if (!isNumberChar(*F1P) || !isNumberChar(*F2P)) {
// The diff failed.
F1NumEnd = F1P;
F2NumEnd = F2P;
} else {
// 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.
V1 = strtod(F1P, const_cast<char**>(&F1NumEnd));
V2 = strtod(F2P, const_cast<char**>(&F2NumEnd));
if (*F1NumEnd == 'D' || *F1NumEnd == 'd') {
// Copy string into tmp buffer to replace the 'D' with an 'e'.
SmallString<200> StrTmp(F1P, EndOfNumber(F1NumEnd)+1);
// Strange exponential notation!
StrTmp[static_cast<unsigned>(F1NumEnd-F1P)] = 'e';
V1 = strtod(&StrTmp[0], const_cast<char**>(&F1NumEnd));
F1NumEnd = F1P + (F1NumEnd-&StrTmp[0]);
}
if (*F2NumEnd == 'D' || *F2NumEnd == 'd') {
// Copy string into tmp buffer to replace the 'D' with an 'e'.
SmallString<200> StrTmp(F2P, EndOfNumber(F2NumEnd)+1);
// Strange exponential notation!
StrTmp[static_cast<unsigned>(F2NumEnd-F2P)] = 'e';
V2 = strtod(&StrTmp[0], const_cast<char**>(&F2NumEnd));
F2NumEnd = F2P + (F2NumEnd-&StrTmp[0]);
}
}
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;
}
// 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) {
raw_string_ostream(*ErrorMsg)
<< "Compared: " << V1 << " and " << V2 << '\n'
<< "abs. diff = " << std::abs(V1-V2) << " rel.diff = " << Diff << '\n'
<< "Out of tolerance: rel/abs: " << RelTolerance << '/'
<< AbsTolerance;
}
return true;
}
}
// Otherwise, advance our read pointers to the end of the numbers.
F1P = F1NumEnd; F2P = F2NumEnd;
return false;
}
/// 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.
///
int llvm::DiffFilesWithTolerance(StringRef NameA,
StringRef NameB,
double AbsTol, double RelTol,
std::string *Error) {
// Now its safe to mmap the files into memory because both files
// have a non-zero size.
ErrorOr<std::unique_ptr<MemoryBuffer>> F1OrErr = MemoryBuffer::getFile(NameA);
if (std::error_code EC = F1OrErr.getError()) {
if (Error)
*Error = EC.message();
return 2;
}
MemoryBuffer &F1 = *F1OrErr.get();
ErrorOr<std::unique_ptr<MemoryBuffer>> F2OrErr = MemoryBuffer::getFile(NameB);
if (std::error_code EC = F2OrErr.getError()) {
if (Error)
*Error = EC.message();
return 2;
}
MemoryBuffer &F2 = *F2OrErr.get();
// Okay, now that we opened the files, scan them for the first difference.
const char *File1Start = F1.getBufferStart();
const char *File2Start = F2.getBufferStart();
const char *File1End = F1.getBufferEnd();
const char *File2End = F2.getBufferEnd();
const char *F1P = File1Start;
const char *F2P = File2Start;
uint64_t A_size = F1.getBufferSize();
uint64_t B_size = F2.getBufferSize();
// Are the buffers identical? Common case: Handle this efficiently.
if (A_size == B_size &&
std::memcmp(File1Start, File2Start, A_size) == 0)
return 0;
// Otherwise, we are done a tolerances are set.
if (AbsTol == 0 && RelTol == 0) {
if (Error)
*Error = "Files differ without tolerance allowance";
return 1; // Files different!
}
bool CompareFailed = false;
while (true) {
// 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;
}
return CompareFailed;
}