QDoc: Remove `QmlCodeParser::m_parser`

As part of producing a documentation set, QDoc parses a series of
user-defined input source files in various languages to extract the
user-provided documentation and certain source-code level elements.

For QML source files, the `QmlCodeParser` class is used, taking care of
reading the QML code and build an internal representation for some of
its elements.

`QmlCodeParser` uses the `QQmlJs` parsing api to do so.
As part of using the `QQmlJs` parsing api, `QmlCodeParser` has to build
a `QQmlJs::Engine`, `QQmlJs::Lexer` and `QQmlJsEngine::Parser`.

Currently, `QmlCodeParser` stores the engine and parser elements as
instance members.
For example, for the `QQmlJs::Parser` instance, a member
variable `m_parser` is used as storage.
Supposedly, this is intended as a way to avoid building the three
elements more than once.

Building a `QQmlJs::Parser` more than once does not provide any
meaningful overhead, moreover not in the code path where it is used.
Furthermore, `m_parser` is used only a few times, in
`QmlCodeParser::parseSourceFile`, the entry point for parsing a QML
source file.

Hence, to reduce the scope of `m_parser` and avoid requiring an
out-of-scope initialization for it, `m_parser` is now removed in favor
of a local instance in `QmlCodeParser::parseSourceFile`.

The initialization and deletion of `m_parser` in
`QmlCodeParser::initializeParser` and `QmlCodeParser::terminateParser`
was removed as a consequence of the removal of the member.

As `QmlCodeParser::initializeParser` and
`QmlCodeParser::terminateParser` were only taking care of `m_parser`,
their implementation is now removed as dead code.
As `initializeParser` and `terminateParser`are required to be
implemented, by `CodeParser`, `QmlCodeParser` base class, due to their
pure virtual nature, an empty implementation was added to
"qmlcodeparser.h".

Similarly, the constructor for `QmlCodeParser` was only taking care of
initializing `m_parser` and is now removed in favor of a defaulted
implementation.

Change-Id: Id07e6d9cf8083c83482232606fb9a2611dcce420
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

0 files changed, 0 insertions, 0 deletions