From a99b78bf51c21465f59f6b7a0a4883c42dc8092f Mon Sep 17 00:00:00 2001 From: Marc Mutz Date: Mon, 24 Mar 2025 12:11:04 +0100 Subject: [PATCH] qcompare.h: standardize on Coverity-friendly ctors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Coverity complained that the Qt::strong_ordering(std::strong_ordering) ctor may leave m_order uninitialized, which is true if you assume that 'stdorder' could be anything else but {less, greater, equal}, which, however, should not happen™. Standardize on the pattern that QPartialOrdering(Qt::partial_ordering) was using: init m_order to equivalent, and then check for the other possible states. I would have preferred adding 'else Q_UNREACHABLE()', but these are constexpr functions, so we'd need the GCC 8 protection, and then the else would have a body longer than one line, and I don't know whether violating the coding style and adding {} only on the else would fly with reviewers, so that's done in a follow-up. Amends several changes (this code has seen a lot of churn over time). Coverity-Id: 475148 Change-Id: I3d88cdaaffbdfb8720161470b5f89046a3a15088 Reviewed-by: Ivan Solovev Reviewed-by: Thiago Macieira (cherry picked from commit f6d878d5ce4d6e41c088698bd337cf7f4438433e) Reviewed-by: Qt Cherry-pick Bot (cherry picked from commit da619f9e0b855d1c4b72820ed304ae8229f76829) --- src/corelib/global/qcompare.h | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/src/corelib/global/qcompare.h b/src/corelib/global/qcompare.h index 9e1afe7527e..f2c87c0551c 100644 --- a/src/corelib/global/qcompare.h +++ b/src/corelib/global/qcompare.h @@ -143,11 +143,10 @@ public: #ifdef __cpp_lib_three_way_comparison constexpr Q_IMPLICIT partial_ordering(std::partial_ordering stdorder) noexcept + : m_order{} // == equivalent { if (stdorder == std::partial_ordering::less) m_order = static_cast(QtPrivate::Ordering::Less); - else if (stdorder == std::partial_ordering::equivalent) - m_order = static_cast(QtPrivate::Ordering::Equivalent); else if (stdorder == std::partial_ordering::greater) m_order = static_cast(QtPrivate::Ordering::Greater); else if (stdorder == std::partial_ordering::unordered) @@ -337,11 +336,10 @@ public: #ifdef __cpp_lib_three_way_comparison constexpr Q_IMPLICIT weak_ordering(std::weak_ordering stdorder) noexcept + : m_order{} // == equivalent { if (stdorder == std::weak_ordering::less) m_order = static_cast(QtPrivate::Ordering::Less); - else if (stdorder == std::weak_ordering::equivalent) - m_order = static_cast(QtPrivate::Ordering::Equivalent); else if (stdorder == std::weak_ordering::greater) m_order = static_cast(QtPrivate::Ordering::Greater); } @@ -533,13 +531,10 @@ public: #ifdef __cpp_lib_three_way_comparison constexpr Q_IMPLICIT strong_ordering(std::strong_ordering stdorder) noexcept + : m_order{} // == equivalent { if (stdorder == std::strong_ordering::less) m_order = static_cast(QtPrivate::Ordering::Less); - else if (stdorder == std::strong_ordering::equivalent) - m_order = static_cast(QtPrivate::Ordering::Equivalent); - else if (stdorder == std::strong_ordering::equal) - m_order = static_cast(QtPrivate::Ordering::Equal); else if (stdorder == std::strong_ordering::greater) m_order = static_cast(QtPrivate::Ordering::Greater); } @@ -802,11 +797,10 @@ public: #ifdef __cpp_lib_three_way_comparison constexpr Q_IMPLICIT QPartialOrdering(std::partial_ordering stdorder) noexcept + : m_order{} // == equivalent { if (stdorder == std::partial_ordering::less) m_order = static_cast(QtPrivate::Ordering::Less); - else if (stdorder == std::partial_ordering::equivalent) - m_order = static_cast(QtPrivate::Ordering::Equivalent); else if (stdorder == std::partial_ordering::greater) m_order = static_cast(QtPrivate::Ordering::Greater); else if (stdorder == std::partial_ordering::unordered)