Bump required Qt version to 5.6

It seems natural to use the LTS release as the minimum required version,
and we get rid of a number of #ifdefs.

[ChangeLog] Building qbs now requires Qt 5.6

Change-Id: I327ebb179a20e6372fa5ae765e0f3753fb9e9efa
Reviewed-by: Jake Petroules <jake.petroules@qt.io>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

9 files changed, 10 insertions, 52 deletions

diff --git a/README b/README
index f3614ca2c..105eff1cb 100644
--- a/README
+++ b/README
@@ -10,12 +10,12 @@ Windows XP SP2 or later
 macOS 10.7 or later
 Linux (tested on Debian 6/7 and Ubuntu 13)
 
-Building the sources requires Qt 5.4.0 or later.
+Building the sources requires Qt 5.6.0 or later.
 
 Build Instructions
 ==================
 Prerequisites:
-   * Qt 5.4.0 or later
+   * Qt 5.6.0 or later
    * On Windows:
      -  MinGW or Visual Studio
    * On macOS: Xcode
diff --git a/doc/qbs.qdoc b/doc/qbs.qdoc
index 0d3d576f2..7a644a53d 100644
--- a/doc/qbs.qdoc
+++ b/doc/qbs.qdoc
@@ -115,7 +115,7 @@
 
     \title System Requirements
 
-    To build \QBS from the source, you need Qt 5.4.0, or later
+    To build \QBS from the source, you need Qt 5.6.0, or later
 
 */
 
diff --git a/qbs-resources/imports/QbsProduct.qbs b/qbs-resources/imports/QbsProduct.qbs
index 7605ba783..fae3336b3 100644
--- a/qbs-resources/imports/QbsProduct.qbs
+++ b/qbs-resources/imports/QbsProduct.qbs
@@ -4,7 +4,7 @@ import QbsFunctions
 Product {
     Depends { name: "qbsbuildconfig" }
     Depends { name: "Qt.core" }
-    property string minimumQtVersion: "5.4.0"
+    property string minimumQtVersion: "5.6.0"
     property bool install: true
     cpp.defines: {
         var res = ["QT_NO_CAST_FROM_ASCII", "QT_NO_PROCESS_COMBINED_ARGUMENT_START"];
diff --git a/qbs.pro b/qbs.pro
index af6ba896a..43c668c98 100644
--- a/qbs.pro
+++ b/qbs.pro
@@ -23,9 +23,9 @@ defineTest(minQtVersion) {
     return(false)
 }
 
-!minQtVersion(5, 4, 0) {
+!minQtVersion(5, 6, 0) {
     message("Cannot build qbs with Qt version $${QT_VERSION}.")
-    error("Use at least Qt 5.4.0.")
+    error("Use at least Qt 5.6.0.")
 }
 
 TEMPLATE = subdirs
diff --git a/src/lib/corelib/buildgraph/rulecommands.cpp b/src/lib/corelib/buildgraph/rulecommands.cpp
index ce50bcfcf..73f5fcfc3 100644
--- a/src/lib/corelib/buildgraph/rulecommands.cpp
+++ b/src/lib/corelib/buildgraph/rulecommands.cpp
@@ -219,16 +219,6 @@ void ProcessCommand::getEnvironmentFromList(const QStringList &envList)
     }
 }
 
-static bool processEnvironmentsAreEqual(const QProcessEnvironment &env1,
-                                        const QProcessEnvironment &env2)
-{
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
-    return env1 == env2;
-#else // qtbase/8b5cdc20be
-    return env1.toStringList() == env2.toStringList();
-#endif
-}
-
 bool ProcessCommand::equals(const AbstractCommand *otherAbstractCommand) const
 {
     if (!AbstractCommand::equals(otherAbstractCommand))
@@ -245,7 +235,7 @@ bool ProcessCommand::equals(const AbstractCommand *otherAbstractCommand) const
             && m_responseFileUsagePrefix == other->m_responseFileUsagePrefix
             && m_stdoutFilePath == other->m_stdoutFilePath
             && m_stderrFilePath == other->m_stderrFilePath
-            && processEnvironmentsAreEqual(m_environment, other->m_environment);
+            && m_environment == other->m_environment;
 }
 
 void ProcessCommand::fillFromScriptValue(const QScriptValue *scriptValue, const CodeLocation &codeLocation)
diff --git a/src/lib/corelib/jsextensions/propertylistutils.mm b/src/lib/corelib/jsextensions/propertylistutils.mm
index a8cda4d12..4ab5831a1 100644
--- a/src/lib/corelib/jsextensions/propertylistutils.mm
+++ b/src/lib/corelib/jsextensions/propertylistutils.mm
@@ -45,27 +45,6 @@
 #include <QtCore/qstring.h>
 #include <QtCore/qvariant.h>
 
-static inline QDateTime QDateTime_fromNSDate(const NSDate *date)
-{
-#if QT_VERSION >= QT_VERSION_CHECK(5, 5, 0)
-    return QDateTime::fromNSDate(date);
-#else
-    if (!date)
-        return QDateTime();
-    return QDateTime::fromMSecsSinceEpoch(static_cast<qint64>([date timeIntervalSince1970] * 1000));
-#endif
-}
-
-static inline NSDate *QDateTime_toNSDate(const QDateTime &qdatetime)
-{
-#if QT_VERSION >= QT_VERSION_CHECK(5, 5, 0)
-    return qdatetime.toNSDate();
-#else
-    return [NSDate
-        dateWithTimeIntervalSince1970:static_cast<NSTimeInterval>(qdatetime.toMSecsSinceEpoch()) / 1000];
-#endif
-}
-
 static QVariant fromObject(id obj);
 static QVariantMap fromDictionary(NSDictionary *dict);
 static QVariantList fromArray(NSArray *array);
@@ -84,7 +63,7 @@ static QVariant fromObject(id obj)
     } else if ([obj isKindOfClass:[NSData class]]) {
         value = QByteArray::fromNSData(obj);
     } else if ([obj isKindOfClass:[NSDate class]]) {
-        value = QDateTime_fromNSDate(obj);
+        value = QDateTime::fromNSDate(obj);
     } else if ([obj isKindOfClass:[NSNumber class]]) {
         if (strcmp([(NSNumber *)obj objCType], @encode(BOOL)) == 0) {
             value = static_cast<bool>([obj boolValue]);
@@ -160,7 +139,7 @@ static id toObject(const QVariant &variant)
         return variant.toByteArray().toNSData();
     } else if (variant.type() == QVariant::Date ||
                variant.type() == QVariant::DateTime) {
-        return QDateTime_toNSDate(variant.toDateTime());
+        return variant.toDateTime().toNSDate();
     } else if (variant.type() == QVariant::Bool) {
         return variant.toBool()
                 ? [NSNumber numberWithBool:YES]
diff --git a/src/lib/corelib/tools/buildgraphlocker.cpp b/src/lib/corelib/tools/buildgraphlocker.cpp
index fa87b9105..eec88bcfe 100644
--- a/src/lib/corelib/tools/buildgraphlocker.cpp
+++ b/src/lib/corelib/tools/buildgraphlocker.cpp
@@ -55,11 +55,6 @@
 namespace qbs {
 namespace Internal {
 
-static bool hasQtBug45497()
-{
-    return Version::fromString(QLatin1String(qVersion())) < Version(5, 5, 1);
-}
-
 static bool hasQtBug53392()
 {
     if (!HostOsInfo::isWindowsHost())
@@ -102,7 +97,7 @@ BuildGraphLocker::BuildGraphLocker(const QString &buildGraphFilePath, const Logg
             QString hostName;
             QString appName;
             if (m_lockFile.getLockInfo(&pid, &hostName, &appName)) {
-                if ((!hasQtBug45497() && !hasQtBug53392()) || appName == processNameByPid(pid)) {
+                if ((!hasQtBug53392()) || appName == processNameByPid(pid)) {
                     throw ErrorInfo(Tr::tr("Cannot lock build graph file '%1': "
                                            "Already locked by '%2' (PID %3).")
                                     .arg(buildGraphFilePath, appName).arg(pid));
diff --git a/src/lib/corelib/tools/set.h b/src/lib/corelib/tools/set.h
index e9af40b42..67a65aa67 100644
--- a/src/lib/corelib/tools/set.h
+++ b/src/lib/corelib/tools/set.h
@@ -70,10 +70,8 @@ template<typename T> class Set
 public:
     using const_iterator = typename QVector<T>::const_iterator;
     using iterator = typename QVector<T>::iterator;
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     using reverse_iterator = typename QVector<T>::reverse_iterator;
     using const_reverse_iterator = typename QVector<T>::const_reverse_iterator;
-#endif
     using size_type = typename QVector<T>::size_type;
     using value_type = T;
     using difference_type = typename QVector<T>::difference_type;
@@ -84,14 +82,12 @@ public:
 
     iterator begin() { return m_data.begin(); }
     iterator end() { return m_data.end(); }
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     reverse_iterator rbegin() { return m_data.rbegin(); }
     reverse_iterator rend() { return m_data.rend(); }
     const_reverse_iterator rbegin() const { return m_data.rbegin(); }
     const_reverse_iterator rend() const { return m_data.rend(); }
     const_reverse_iterator crbegin() const { return m_data.crbegin(); }
     const_reverse_iterator crend() const { return m_data.crend(); }
-#endif
     const_iterator begin() const { return m_data.begin(); }
     const_iterator end() const { return m_data.end(); }
     const_iterator cbegin() const { return m_data.cbegin(); }
diff --git a/src/lib/corelib/tools/tst_tools.cpp b/src/lib/corelib/tools/tst_tools.cpp
index bb4ba469d..1689668e0 100644
--- a/src/lib/corelib/tools/tst_tools.cpp
+++ b/src/lib/corelib/tools/tst_tools.cpp
@@ -702,7 +702,6 @@ void TestTools::set_insert()
 
 void TestTools::set_reverseIterators()
 {
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     Set<int> s;
     s << 1 << 17 << 61 << 127 << 911;
     std::vector<int> v(s.begin(), s.end());
@@ -714,7 +713,6 @@ void TestTools::set_reverseIterators()
     QVERIFY(std::equal(s.rbegin(), s.rend(), v.begin()));
     QVERIFY(std::equal(s.crbegin(), s.crend(), v.begin()));
     QVERIFY(std::equal(cs.rbegin(), cs.rend(), v.begin()));
-#endif
 }
 
 void TestTools::set_stlIterator()