blob: 7bdf1271ac25f9819efee27e9bb8d936ae656512 [file] [log] [blame]
//===- LineIterator.cpp - Implementation of line iteration ----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/LineIterator.h"
#include "llvm/Support/MemoryBuffer.h"
using namespace llvm;
static bool isAtLineEnd(const char *P) {
if (*P == '\n')
return true;
if (*P == '\r' && *(P + 1) == '\n')
return true;
return false;
}
static bool skipIfAtLineEnd(const char *&P) {
if (*P == '\n') {
++P;
return true;
}
if (*P == '\r' && *(P + 1) == '\n') {
P += 2;
return true;
}
return false;
}
line_iterator::line_iterator(const MemoryBuffer &Buffer, bool SkipBlanks,
char CommentMarker)
: line_iterator(Buffer.getMemBufferRef(), SkipBlanks, CommentMarker) {}
line_iterator::line_iterator(const MemoryBufferRef &Buffer, bool SkipBlanks,
char CommentMarker)
: Buffer(Buffer.getBufferSize() ? Optional<MemoryBufferRef>(Buffer) : None),
CommentMarker(CommentMarker), SkipBlanks(SkipBlanks), LineNumber(1),
CurrentLine(Buffer.getBufferSize() ? Buffer.getBufferStart() : nullptr,
0) {
// Ensure that if we are constructed on a non-empty memory buffer that it is
// a null terminated buffer.
if (Buffer.getBufferSize()) {
assert(Buffer.getBufferEnd()[0] == '\0');
// Make sure we don't skip a leading newline if we're keeping blanks
if (SkipBlanks || !isAtLineEnd(Buffer.getBufferStart()))
advance();
}
}
void line_iterator::advance() {
assert(Buffer && "Cannot advance past the end!");
const char *Pos = CurrentLine.end();
assert(Pos == Buffer->getBufferStart() || isAtLineEnd(Pos) || *Pos == '\0');
if (skipIfAtLineEnd(Pos))
++LineNumber;
if (!SkipBlanks && isAtLineEnd(Pos)) {
// Nothing to do for a blank line.
} else if (CommentMarker == '\0') {
// If we're not stripping comments, this is simpler.
while (skipIfAtLineEnd(Pos))
++LineNumber;
} else {
// Skip comments and count line numbers, which is a bit more complex.
for (;;) {
if (isAtLineEnd(Pos) && !SkipBlanks)
break;
if (*Pos == CommentMarker)
do {
++Pos;
} while (*Pos != '\0' && !isAtLineEnd(Pos));
if (!skipIfAtLineEnd(Pos))
break;
++LineNumber;
}
}
if (*Pos == '\0') {
// We've hit the end of the buffer, reset ourselves to the end state.
Buffer = None;
CurrentLine = StringRef();
return;
}
// Measure the line.
size_t Length = 0;
while (Pos[Length] != '\0' && !isAtLineEnd(&Pos[Length])) {
++Length;
}
CurrentLine = StringRef(Pos, Length);
}