QProcessEnvironment: Use new comparison helper macros

QProcessEnvironment had operator==() and operator!=() defined as public
member functions, so use QT_CORE_REMOVED_SINCE and removed_api.cpp to
get rid of these methods and replace them with a hidden friend.

Use QT_TEST_ALL_EQUALITY_OPS macro in unit-tests.

Use new \compares command in the documentation to describe the
comparison operators provided by QProcessEnvironment.

Task-number: QTBUG-120303
Change-Id: I4c57f6cfb9589e82a37eea6993e079212b34cecd
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

src/corelib/compat/removed_api.cpp

@@ -938,6 +938,15 @@ bool QFileInfo::operator==(const QFileInfo &fileinfo) const
     return comparesEqual(*this, fileinfo);
 }
 
+#if QT_CONFIG(processenvironment)
+#include "qprocess.h" // inlined API
+
+bool QProcessEnvironment::operator==(const QProcessEnvironment &other) const
+{
+    return comparesEqual(*this, other);
+}
+#endif // QT_CONFIG(processenvironment)
+
 // #include "qotherheader.h"
 // // implement removed functions from qotherheader.h
 // order sections alphabetically to reduce chances of merge conflicts

src/corelib/io/qprocess.cpp

@@ -35,6 +35,8 @@ QT_BEGIN_NAMESPACE
     \reentrant
     \since 4.6
 
+    \compares equality
+
     A process's environment is composed of a set of key=value pairs known as
     environment variables. The QProcessEnvironment class wraps that concept
     and allows easy manipulation of those variables. It's meant to be used
@@ -184,15 +186,17 @@ QProcessEnvironment &QProcessEnvironment::operator=(const QProcessEnvironment &o
 */
 
 /*!
-    \fn bool QProcessEnvironment::operator !=(const QProcessEnvironment &other) const
+    \fn bool QProcessEnvironment::operator!=(const QProcessEnvironment &lhs, const QProcessEnvironment &rhs)
 
-    Returns \c true if this and the \a other QProcessEnvironment objects are different.
+    Returns \c true if the process environment objects \a lhs and \a rhs are different.
 
     \sa operator==()
 */
 
 /*!
-    Returns \c true if this and the \a other QProcessEnvironment objects are equal.
+   \fn bool QProcessEnvironment::operator==(const QProcessEnvironment &lhs, const QProcessEnvironment &rhs)
+
+    Returns \c true if the process environment objects \a lhs and \a rhs are equal.
 
     Two QProcessEnvironment objects are considered equal if they have the same
     set of key=value pairs. The comparison of keys is done case-sensitive on
@@ -200,12 +204,12 @@ QProcessEnvironment &QProcessEnvironment::operator=(const QProcessEnvironment &o
 
     \sa operator!=(), contains()
 */
-bool QProcessEnvironment::operator==(const QProcessEnvironment &other) const
+bool comparesEqual(const QProcessEnvironment &lhs, const QProcessEnvironment &rhs)
 {
-    if (d == other.d)
+    if (lhs.d == rhs.d)
         return true;
 
-    return d && other.d && d->vars == other.d->vars;
+    return lhs.d && rhs.d && lhs.d->vars == rhs.d->vars;
 }
 
 /*!

src/corelib/io/qprocess.h

@@ -5,6 +5,7 @@
 #ifndef QPROCESS_H
 #define QPROCESS_H
 
+#include <QtCore/qcompare.h>
 #include <QtCore/qiodevice.h>
 #include <QtCore/qstringlist.h>
 #include <QtCore/qshareddata.h>
@@ -41,9 +42,11 @@ public:
 
     void swap(QProcessEnvironment &other) noexcept { d.swap(other.d); }
 
+#if QT_CORE_REMOVED_SINCE(6, 8)
     bool operator==(const QProcessEnvironment &other) const;
     inline bool operator!=(const QProcessEnvironment &other) const
-    { return !(*this == other); }
+    { return !operator==(other); }
+#endif
 
     bool isEmpty() const;
     [[nodiscard]] bool inheritsFromParent() const;
@@ -63,6 +66,9 @@ public:
     static QProcessEnvironment systemEnvironment();
 
 private:
+    friend Q_CORE_EXPORT bool comparesEqual(const QProcessEnvironment &lhs,
+                                            const QProcessEnvironment &rhs);
+    Q_DECLARE_EQUALITY_COMPARABLE(QProcessEnvironment)
     friend class QProcessPrivate;
     friend class QProcessEnvironmentPrivate;
     QSharedDataPointer<QProcessEnvironmentPrivate> d;

tests/auto/corelib/io/qprocessenvironment/CMakeLists.txt

@@ -14,4 +14,6 @@ endif()
 qt_internal_add_test(tst_qprocessenvironment
     SOURCES
         tst_qprocessenvironment.cpp
+    LIBRARIES
+        Qt::TestPrivate
 )

tests/auto/corelib/io/qprocessenvironment/tst_qprocessenvironment.cpp

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
 #include <QTest>
+#include <QtTest/private/qcomparisontesthelper_p.h>
 #include <QObject>
 #include <QProcessEnvironment>
 
@@ -9,6 +10,7 @@ class tst_QProcessEnvironment: public QObject
 {
     Q_OBJECT
 private slots:
+    void compareCompiles();
     void operator_eq();
     void clearAndIsEmpty();
     void clearAndInheritsFromParent();
@@ -23,6 +25,11 @@ private slots:
     void putenv();
 };
 
+void tst_QProcessEnvironment::compareCompiles()
+{
+    QTestPrivate::testEqualityOperatorsCompile<QProcessEnvironment>();
+}
+
 void tst_QProcessEnvironment::operator_eq()
 {
     QProcessEnvironment e1;
@@ -35,8 +42,7 @@ void tst_QProcessEnvironment::operator_eq()
     QCOMPARE(e1, e2);
 
     auto parentEnv = QProcessEnvironment(QProcessEnvironment::InheritFromParent);
-    QVERIFY(parentEnv != e2);
-    QVERIFY(e2 != parentEnv);
+    QT_TEST_EQUALITY_OPS(parentEnv, e2, false);
 
     e1.clear();
     QCOMPARE(e1, e2);
@@ -45,16 +51,15 @@ void tst_QProcessEnvironment::operator_eq()
     QCOMPARE(e1, e2);
 
     e1.insert("FOO", "bar");
-    QVERIFY(e1 != e2);
+    QT_TEST_EQUALITY_OPS(e1, e2, false);
 
     e2.insert("FOO", "bar");
     QCOMPARE(e1, e2);
 
     e2.insert("FOO", "baz");
-    QVERIFY(e1 != e2);
+    QT_TEST_EQUALITY_OPS(e1, e2, false);
 
-    QVERIFY(e2 != parentEnv);
-    QVERIFY(parentEnv != e2);
+    QT_TEST_EQUALITY_OPS(e2, parentEnv, false);
 }
 
 void tst_QProcessEnvironment::clearAndIsEmpty()