Fix alignment-warnings about Q_DECLARE_PRIVATE's casts

Q_DECLARE_PRIVATE gets used in the declaration of the public class,
where the private class is typically visible only as a forward-decl,
with no knowledge of what it's based on; consequently, the macro is
obliged to use reinterpret_cast<>, which is subject to warnings when
the compiler *can* see both types and their alignments differ.  The
same applies to Q_DECLARE_PRIVATE_D.

So suppress gcc's -Wcast-align around the d_func() return statements.
(If we get similar problems with other compilers we can add their
suppressions likewise; but, for now, we've only seen this on MIPS64,
where we use gcc.)  This tripped over one use of Q_DECLARE_PRIVATE in
a private Q_SLOTS: section; for some reason, gcc didn't like the
semicolon on the friend declaration.  Changing the context to plain
private fixed that.

Fixes: QTBUG-72885
Change-Id: I5edc11d46bd4eb820713adede79d53191a7e2736
Reviewed-by: Liang Qi <liang.qi@qt.io>
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>
Reviewed-by: Boxiang Sun <daetalusun@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/network/access/qnetworkreplyfileimpl_p.h b/src/network/access/qnetworkreplyfileimpl_p.h
index 55aece0bed..48d82abd3f 100644
--- a/src/network/access/qnetworkreplyfileimpl_p.h
+++ b/src/network/access/qnetworkreplyfileimpl_p.h
@@ -80,6 +80,7 @@ public:
 private Q_SLOTS:
     void fileOpenFinished(bool isOpen);
 
+private:
     Q_DECLARE_PRIVATE(QNetworkReplyFileImpl)
 };