They were lacking it since the start of the public history, and
porting to std::snprintf() (which has the warning) as part of making
Qt compile with QT_NO_SNPRINTF has turned up surprisingly many
-Wformat warnings, so enable the warning for the remaining (non-tree)
users.
Backporting aggressively, as this might unearth security bugs in user
code.
[ChangeLog][QtCore][q(v)snprintf] Added attributes for GCC-compatible
compilers to detect format/argument mismatches. If this throws warnings
for your calls now, don't ignore them. printf() format mistakes could
be security-relevant. You may also find that you relied on undocumented
behavior, such as that certain implementations (Windows, Android, WASM)
of qsnprintf() support char16_t* instead of wchar_t* for %ls. In that
case, you should port to qUtf16Printable() and QString::asprintf(), or
suppress the warning and port away from the platform dependence at your
earliest convenience.
Task-number: QTBUG-127110
Pick-to: 6.7 6.5 6.2 5.15
Change-Id: I5c1fd9b2d5d2d55c68773f33edfd76acacd2408c
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Jason McDonald <macadder1@gmail.com>
(cherry picked from commit 64416d3cf645187385d8ad90bc44d9c8e9ce864f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
42c467a11d