1 files changed, 107 insertions, 0 deletions
diff --git a/src/tools/clangbackend/source/utf8positionfromlinecolumn.cpp b/src/tools/clangbackend/source/utf8positionfromlinecolumn.cpp
new file mode 100644
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+++ b/src/tools/clangbackend/source/utf8positionfromlinecolumn.cpp
@@ -0,0 +1,107 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "utf8positionfromlinecolumn.h"
+
+#include <QtGlobal>
+
+namespace ClangBackEnd {
+
+Utf8PositionFromLineColumn::Utf8PositionFromLineColumn(const char *utf8Text)
+    : m_utf8Text(utf8Text)
+    , m_currentByte(utf8Text)
+{
+}
+
+bool Utf8PositionFromLineColumn::find(uint line, uint column)
+{
+    if (!m_utf8Text || *m_utf8Text == '\0' || line == 0 || column == 0)
+        return false;
+
+    return advanceToLine(line)
+        && advanceToColumn(column);
+}
+
+uint Utf8PositionFromLineColumn::position() const
+{
+    return m_previousByte - m_utf8Text;
+}
+
+bool Utf8PositionFromLineColumn::advanceToLine(uint line)
+{
+    if (line == 1)
+        return true;
+
+    uint currentLine = 1;
+    do {
+        if (*m_currentByte == '\n' && ++currentLine == line) {
+            advanceCodePoint();
+            return true;
+        }
+    } while (advanceCodePoint());
+
+    return false;
+}
+
+bool Utf8PositionFromLineColumn::advanceToColumn(uint column)
+{
+    while (column) {
+        if (advanceCodePoint(/*stopOnNewLine=*/ true))
+            --column;
+        else
+            break;
+    }
+
+    return column == 0;
+}
+
+static bool isByteOfMultiByteCodePoint(unsigned char byte)
+{
+    return byte & 0x80; // Check if most significant bit is set
+}
+
+bool Utf8PositionFromLineColumn::advanceCodePoint(bool stopOnNewLine)
+{
+    if (Q_UNLIKELY(*m_currentByte == '\0') || (stopOnNewLine && *m_currentByte == '\n'))
+        return false;
+
+    m_previousByte = m_currentByte;
+
+    // Process multi-byte UTF-8 code point (non-latin1)
+    if (Q_UNLIKELY(isByteOfMultiByteCodePoint(*m_currentByte))) {
+        unsigned trailingBytesCurrentCodePoint = 1;
+        for (unsigned char c = (*m_currentByte) << 2; isByteOfMultiByteCodePoint(c); c <<= 1)
+            ++trailingBytesCurrentCodePoint;
+        m_currentByte += trailingBytesCurrentCodePoint + 1;
+
+    // Process single-byte UTF-8 code point (latin1)
+    } else {
+        ++m_currentByte;
+    }
+
+    return true;
+}
+
+} // namespace ClangBackEnd