| //===- 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); |
| } |