98 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			98 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===- 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),
 | |
|       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);
 | |
| }
 |