[C++] Rewrite of the preprocessor.

This rewrite fixes a couple of issues with the pre-processor. It now
supports:
- macros in macro bodies
- stringification of parameters [cpp.stringize]
- the concatenation operator [cpp.concat]
- #include MACRO_HERE
- defined() inside macro bodies used in pp-conditions.

Change-Id: Ifdb78041fb6afadf44f939a4bd66ce2832b8601f
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/libs/cplusplus/PPToken.h

@@ -0,0 +1,106 @@
+#ifndef CPLUSPLUS_INTERNAL_PPTOKEN_H
+#define CPLUSPLUS_INTERNAL_PPTOKEN_H
+
+#include <CPlusPlus.h>
+#include <Token.h>
+
+#include <QByteArray>
+
+namespace CPlusPlus {
+namespace Internal {
+
+class CPLUSPLUS_EXPORT ByteArrayRef
+{
+public:
+    ByteArrayRef();
+
+    ByteArrayRef(const QByteArray *ref)
+        : m_ref(ref)
+        , m_offset(0)
+        , m_length(ref->length())
+    {}
+
+    ByteArrayRef(const QByteArray *ref, int offset, int length)
+        : m_ref(ref)
+        , m_offset(offset)
+        , m_length(length)
+    {
+        Q_ASSERT(ref);
+        Q_ASSERT(offset >= 0);
+        Q_ASSERT(length >= 0);
+        Q_ASSERT(offset + length <= ref->size());
+    }
+
+    inline const char *start() const
+    { return m_ref ? m_ref->constData() + m_offset : 0; }
+
+    inline int length() const
+    { return m_length; }
+
+    inline int size() const
+    { return length(); }
+
+    inline char at(int pos) const
+    { return m_ref && pos >= 0 && pos < m_length ? m_ref->at(m_offset + pos) : '\0'; }
+
+    inline char operator[](int pos) const
+    { return at(pos); }
+
+    QByteArray toByteArray() const
+    { return m_ref ? QByteArray(m_ref->constData() + m_offset, m_length) : QByteArray(); }
+
+    bool operator==(const QByteArray &other) const
+    { return m_ref ? (m_length == other.length() && !qstrncmp(m_ref->constData() + m_offset, other.constData(), m_length)) : false; }
+    bool operator!=(const QByteArray &other) const
+    { return !this->operator==(other); }
+
+    bool startsWith(const char *ch) const;
+
+    int count(char c) const;
+
+private:
+    const QByteArray *m_ref;
+    int m_offset;
+    int m_length;
+};
+
+inline bool operator==(const QByteArray &other, const ByteArrayRef &ref)
+{ return ref == other; }
+
+inline bool operator!=(const QByteArray &other, const ByteArrayRef &ref)
+{ return ref != other; }
+
+class CPLUSPLUS_EXPORT PPToken: public Token
+{
+public:
+    PPToken();
+
+    PPToken(const QByteArray &src)
+        : m_src(src)
+    {}
+
+    void setSource(const QByteArray &src)
+    { m_src = src; }
+
+    const QByteArray &source() const
+    { return m_src; }
+
+    const char *start() const
+    { return m_src.constData() + offset; }
+
+    ByteArrayRef asByteArrayRef() const
+    { return ByteArrayRef(&m_src, offset, length()); }
+
+    bool isValid() const
+    { return !m_src.isEmpty(); }
+
+    void squeeze();
+
+private:
+    QByteArray m_src;
+};
+
+} // namespace Internal
+} // namespace CPlusPlus
+
+#endif // CPLUSPLUS_INTERNAL_PPTOKEN_H