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// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "Input.h"
#include <algorithm>
#include <cassert>
#include <cstring>
namespace pp
{
Input::Input() : mCount(0), mString(0)
{
}
Input::~Input()
{
}
Input::Input(size_t count, const char *const string[], const int length[])
: mCount(count), mString(string)
{
mLength.reserve(mCount);
for (size_t i = 0; i < mCount; ++i)
{
int len = length ? length[i] : -1;
mLength.push_back(len < 0 ? std::strlen(mString[i]) : len);
}
}
const char *Input::skipChar()
{
// This function should only be called when there is a character to skip.
assert(mReadLoc.cIndex < mLength[mReadLoc.sIndex]);
++mReadLoc.cIndex;
if (mReadLoc.cIndex == mLength[mReadLoc.sIndex])
{
++mReadLoc.sIndex;
mReadLoc.cIndex = 0;
}
if (mReadLoc.sIndex >= mCount)
{
return nullptr;
}
return mString[mReadLoc.sIndex] + mReadLoc.cIndex;
}
size_t Input::read(char *buf, size_t maxSize, int *lineNo)
{
size_t nRead = 0;
// The previous call to read might have stopped copying the string when encountering a line
// continuation. Check for this possibility first.
if (mReadLoc.sIndex < mCount && maxSize > 0)
{
const char *c = mString[mReadLoc.sIndex] + mReadLoc.cIndex;
if ((*c) == '\\')
{
c = skipChar();
if (c != nullptr && (*c) == '\n')
{
// Line continuation of backslash + newline.
skipChar();
// Fake an EOF if the line number would overflow.
if (*lineNo == INT_MAX)
{
return 0;
}
++(*lineNo);
}
else if (c != nullptr && (*c) == '\r')
{
// Line continuation. Could be backslash + '\r\n' or just backslash + '\r'.
c = skipChar();
if (c != nullptr && (*c) == '\n')
{
skipChar();
}
// Fake an EOF if the line number would overflow.
if (*lineNo == INT_MAX)
{
return 0;
}
++(*lineNo);
}
else
{
// Not line continuation, so write the skipped backslash to buf.
*buf = '\\';
++nRead;
}
}
}
size_t maxRead = maxSize;
while ((nRead < maxRead) && (mReadLoc.sIndex < mCount))
{
size_t size = mLength[mReadLoc.sIndex] - mReadLoc.cIndex;
size = std::min(size, maxSize);
for (size_t i = 0; i < size; ++i)
{
// Stop if a possible line continuation is encountered.
// It will be processed on the next call on input, which skips it
// and increments line number if necessary.
if (*(mString[mReadLoc.sIndex] + mReadLoc.cIndex + i) == '\\')
{
size = i;
maxRead = nRead + size; // Stop reading right before the backslash.
}
}
std::memcpy(buf + nRead, mString[mReadLoc.sIndex] + mReadLoc.cIndex, size);
nRead += size;
mReadLoc.cIndex += size;
// Advance string if we reached the end of current string.
if (mReadLoc.cIndex == mLength[mReadLoc.sIndex])
{
++mReadLoc.sIndex;
mReadLoc.cIndex = 0;
}
}
return nRead;
}
} // namespace pp