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5ff21b4111
This is an iterator which you can build around a MemoryBuffer. It will iterate through the non-empty, non-comment lines of the buffer as a forward iterator. It should be small and reasonably fast (although it could be made much faster if anyone cares, I don't really...). This will be used to more simply support the text-based sample profile file format, and is largely based on the original patch by Diego. I've re-worked the style of it and separated it from the work of producing a MemoryBuffer from a file which both simplifies the interface and makes it easier to test. The style of the API follows the C++ standard naming conventions to fit in better with iterators in general, much like the Path and FileSystem interfaces follow standard-based naming conventions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198068 91177308-0d34-0410-b5e6-96231b3b80d8
69 lines
1.9 KiB
C++
69 lines
1.9 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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line_iterator::line_iterator(const MemoryBuffer &Buffer, char CommentMarker)
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: Buffer(Buffer.getBufferSize() ? &Buffer : 0),
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CommentMarker(CommentMarker), LineNumber(1),
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CurrentLine(Buffer.getBufferSize() ? Buffer.getBufferStart() : 0, 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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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() || *Pos == '\n' || *Pos == '\0');
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size_t Length = 0;
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if (CommentMarker == '\0') {
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// If we're not stripping comments, this is simpler.
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while (Pos[Length] == '\n')
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++Length;
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Pos += Length;
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LineNumber += Length;
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Length = 0;
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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 (*Pos == CommentMarker)
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do {
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++Pos;
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} while (*Pos != '\0' && *Pos != '\n');
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if (*Pos != '\n')
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break;
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++Pos;
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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 = 0;
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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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do {
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++Length;
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} while (Pos[Length] != '\0' && Pos[Length] != '\n');
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CurrentLine = StringRef(Pos, Length);
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}
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