//===- LineIterator.cpp - Implementation of line iteration ----------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #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) : Buffer(Buffer.getBufferSize() ? &Buffer : nullptr), 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 = nullptr; CurrentLine = StringRef(); return; } // Measure the line. size_t Length = 0; while (Pos[Length] != '\0' && !isAtLineEnd(&Pos[Length])) { ++Length; } CurrentLine = StringRef(Pos, Length); } |