//===- Support/FileUtilities.cpp - File System Utilities ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <cctype>
#include <cstdlib>
#include <cstring>
#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;
}
std::unique_ptr<MemoryBuffer> F1 = std::move(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;
}
std::unique_ptr<MemoryBuffer> F2 = std::move(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 (1) {
// 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;
}