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The MRI scripts have to work with CRLF, and in general it is probably a good idea to support this in a core utility like LineIterator. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221153 91177308-0d34-0410-b5e6-96231b3b80d8
95 lines
2.6 KiB
C++
95 lines
2.6 KiB
C++
//===- LineIterator.cpp - Implementation of line iteration ----------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Support/LineIterator.h"
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#include "llvm/Support/MemoryBuffer.h"
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using namespace llvm;
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static bool isAtLineEnd(const char *P) {
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if (*P == '\n')
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return true;
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if (*P == '\r' && *(P + 1) == '\n')
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return true;
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return false;
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}
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static bool skipIfAtLineEnd(const char *&P) {
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if (*P == '\n') {
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++P;
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return true;
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}
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if (*P == '\r' && *(P + 1) == '\n') {
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P += 2;
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return true;
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}
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return false;
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}
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line_iterator::line_iterator(const MemoryBuffer &Buffer, bool SkipBlanks,
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char CommentMarker)
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: Buffer(Buffer.getBufferSize() ? &Buffer : nullptr),
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CommentMarker(CommentMarker), SkipBlanks(SkipBlanks), LineNumber(1),
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CurrentLine(Buffer.getBufferSize() ? Buffer.getBufferStart() : nullptr,
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0) {
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// Ensure that if we are constructed on a non-empty memory buffer that it is
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// a null terminated buffer.
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if (Buffer.getBufferSize()) {
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assert(Buffer.getBufferEnd()[0] == '\0');
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// Make sure we don't skip a leading newline if we're keeping blanks
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if (SkipBlanks || !isAtLineEnd(Buffer.getBufferStart()))
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advance();
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}
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}
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void line_iterator::advance() {
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assert(Buffer && "Cannot advance past the end!");
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const char *Pos = CurrentLine.end();
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assert(Pos == Buffer->getBufferStart() || isAtLineEnd(Pos) || *Pos == '\0');
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if (skipIfAtLineEnd(Pos))
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++LineNumber;
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if (!SkipBlanks && isAtLineEnd(Pos)) {
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// Nothing to do for a blank line.
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} else if (CommentMarker == '\0') {
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// If we're not stripping comments, this is simpler.
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while (skipIfAtLineEnd(Pos))
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++LineNumber;
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} else {
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// Skip comments and count line numbers, which is a bit more complex.
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for (;;) {
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if (isAtLineEnd(Pos) && !SkipBlanks)
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break;
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if (*Pos == CommentMarker)
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do {
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++Pos;
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} while (*Pos != '\0' && !isAtLineEnd(Pos));
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if (!skipIfAtLineEnd(Pos))
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break;
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++LineNumber;
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}
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}
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if (*Pos == '\0') {
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// We've hit the end of the buffer, reset ourselves to the end state.
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Buffer = nullptr;
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CurrentLine = StringRef();
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return;
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}
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// Measure the line.
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size_t Length = 0;
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while (Pos[Length] != '\0' && !isAtLineEnd(&Pos[Length])) {
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++Length;
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}
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CurrentLine = StringRef(Pos, Length);
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}
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