Use unchecked substring methods in date-time code

Change-Id: I38b9aaa0335c6168706c2508ed1117fd908e679c
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Andreas Buhr <andreas.buhr@qt.io>

2 files changed, 31 insertions, 33 deletions

diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp
index c1e56ced07..506430e154 100644
--- a/src/corelib/time/qdatetime.cpp
+++ b/src/corelib/time/qdatetime.cpp
@@ -233,19 +233,19 @@ static ParsedRfcDateTime rfcDateImpl(QStringView s)
             || (when.size() == 8 ? when[5] != colon : when.size() > 5)) {
             return result;
         }
-        const int hour = when.left(2).toInt(&ok);
+        const int hour = when.first(2).toInt(&ok);
         if (!ok)
             return result;
-        const int minute = when.mid(3, 2).toInt(&ok);
+        const int minute = when.sliced(3, 2).toInt(&ok);
         if (!ok)
             return result;
-        const auto secs = when.size() == 8 ? when.right(2).toInt(&ok) : 0;
+        const auto secs = when.size() == 8 ? when.last(2).toInt(&ok) : 0;
         if (!ok)
             return result;
         time = QTime(hour, minute, secs);
     }
 
-    // Offset: [±hhmm]
+    // Offset: [±hh[mm]]
     int offset = 0;
     if (words.size()) {
         const QStringView zone = words.takeFirst();
@@ -256,10 +256,10 @@ static ParsedRfcDateTime rfcDateImpl(QStringView s)
             negate = true;
         else if (zone[0] != u'+')
             return result;
-        const int hour = zone.mid(1, 2).toInt(&ok);
+        const int hour = zone.sliced(1, 2).toInt(&ok);
         if (!ok)
             return result;
-        const auto minute = zone.size() > 3 ? zone.mid(3, 2).toInt(&ok) : 0;
+        const auto minute = zone.size() == 5 ? zone.last(2).toInt(&ok) : 0;
         if (!ok)
             return result;
         offset = (hour * 60 + minute) * 60;
@@ -308,7 +308,7 @@ static int fromOffsetString(QStringView offsetString, bool *valid) noexcept
         return 0;
 
     // Split the hour and minute parts
-    const QStringView time = offsetString.mid(1);
+    const QStringView time = offsetString.sliced(1);
     qsizetype hhLen = time.indexOf(u':');
     qsizetype mmIndex;
     if (hhLen == -1)
@@ -316,13 +316,13 @@ static int fromOffsetString(QStringView offsetString, bool *valid) noexcept
     else
         mmIndex = hhLen + 1;
 
-    const QStringView hhRef = time.left(qMin(hhLen, time.size()));
+    const QStringView hhRef = time.first(qMin(hhLen, time.size()));
     bool ok = false;
     const int hour = hhRef.toInt(&ok);
     if (!ok)
         return 0;
 
-    const QStringView mmRef = time.mid(qMin(mmIndex, time.size()));
+    const QStringView mmRef = time.sliced(qMin(mmIndex, time.size()));
     const int minute = mmRef.isEmpty() ? 0 : mmRef.toInt(&ok);
     if (!ok || minute < 0 || minute > 59)
         return 0;
@@ -1503,9 +1503,9 @@ QDate QDate::fromString(QStringView string, Qt::DateFormat format)
         // Semi-strict parsing, must be long enough and have punctuators as separators
         if (string.size() >= 10 && string.at(4).isPunct() && string.at(7).isPunct()
                 && (string.size() == 10 || !string.at(10).isDigit())) {
-            const ParsedInt year = readInt(string.mid(0, 4));
-            const ParsedInt month = readInt(string.mid(5, 2));
-            const ParsedInt day = readInt(string.mid(8, 2));
+            const ParsedInt year = readInt(string.first(4));
+            const ParsedInt month = readInt(string.sliced(5, 2));
+            const ParsedInt day = readInt(string.sliced(8, 2));
             if (year.ok && year.value > 0 && year.value <= 9999 && month.ok && day.ok)
                 return QDate(year.value, month.value, day.value);
         }
@@ -4791,14 +4791,14 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
         if (size < 10)
             return QDateTime();
 
-        QDate date = QDate::fromString(string.left(10), Qt::ISODate);
+        QDate date = QDate::fromString(string.first(10), Qt::ISODate);
         if (!date.isValid())
             return QDateTime();
         if (size == 10)
             return date.startOfDay();
 
         Qt::TimeSpec spec = Qt::LocalTime;
-        QStringView isoString = string.mid(10); // trim "yyyy-MM-dd"
+        QStringView isoString = string.sliced(10); // trim "yyyy-MM-dd"
 
         // Must be left with T (or space) and at least one digit for the hour:
         if (isoString.size() < 2
@@ -4809,7 +4809,7 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
                  || isoString.startsWith(u' '))) {
             return QDateTime();
         }
-        isoString = isoString.mid(1); // trim 'T' (or space)
+        isoString = isoString.sliced(1); // trim 'T' (or space)
 
         int offset = 0;
         // Check end of string for Time Zone definition, either Z for UTC or [+-]HH:mm for Offset
@@ -4829,10 +4829,10 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
 
             if (found) {
                 bool ok;
-                offset = fromOffsetString(isoString.mid(signIndex), &ok);
+                offset = fromOffsetString(isoString.sliced(signIndex), &ok);
                 if (!ok)
                     return QDateTime();
-                isoString = isoString.left(signIndex);
+                isoString = isoString.first(signIndex);
                 spec = Qt::OffsetFromUTC;
             }
         }
@@ -4883,11 +4883,9 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
         if (!ok || !month || !day) {
             month = fromShortMonthName(parts.at(2));
             if (month) {
-                QStringView  dayStr = parts.at(1);
-                if (dayStr.endsWith(u'.')) {
-                    dayStr = dayStr.left(dayStr.size() - 1);
-                    day = dayStr.toInt(&ok);
-                }
+                QStringView dayPart = parts.at(1);
+                if (dayPart.endsWith(u'.'))
+                    day = dayPart.chopped(1).toInt(&ok);
             }
         }
 
@@ -4909,7 +4907,7 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
         QStringView tz = parts.at(5);
         if (!tz.startsWith(QLatin1String("GMT"), Qt::CaseInsensitive))
             return QDateTime();
-        tz = tz.mid(3);
+        tz = tz.sliced(3);
         if (!tz.isEmpty()) {
             int offset = fromOffsetString(tz, &ok);
             if (!ok)
diff --git a/src/corelib/time/qdatetimeparser.cpp b/src/corelib/time/qdatetimeparser.cpp
index d64b593809..df07e68999 100644
--- a/src/corelib/time/qdatetimeparser.cpp
+++ b/src/corelib/time/qdatetimeparser.cpp
@@ -499,7 +499,7 @@ bool QDateTimeParser::parseFormat(QStringView newFormat)
                 if (parserType != QMetaType::QTime) {
                     const SectionNode sn = { MonthSection, i - add, countRepeat(newFormat, i, 4), 0 };
                     newSectionNodes.append(sn);
-                    newSeparators.append(unquote(newFormat.mid(index, i - index)));
+                    newSeparators.append(unquote(newFormat.first(i).sliced(index)));
                     i += sn.count - 1;
                     index = i + 1;
                     newDisplay |= MonthSection;
@@ -825,7 +825,7 @@ QDateTimeParser::parseSection(const QDateTime &currentValue, int sectionIndex, i
             int last = -1, used = -1;
 
             Q_ASSERT(sectiontextSize <= sectionmaxsize);
-            QStringView digitsStr = sectionTextRef.left(sectiontextSize);
+            QStringView digitsStr = sectionTextRef.first(sectiontextSize);
             for (int digits = sectiontextSize; digits >= 1; --digits) {
                 digitsStr.truncate(digits);
                 int tmp = int(loc.toUInt(digitsStr, &ok));
@@ -838,7 +838,7 @@ QDateTimeParser::parseSection(const QDateTime &currentValue, int sectionIndex, i
                     }
                 }
                 if (ok && tmp <= absMax) {
-                    QDTPDEBUG << sectionTextRef.left(digits) << tmp << digits;
+                    QDTPDEBUG << sectionTextRef.first(digits) << tmp << digits;
                     last = tmp;
                     used = digits;
                     break;
@@ -1185,11 +1185,11 @@ QDateTimeParser::scanString(const QDateTime &defaultValue, bool fixup) const
             current = &zoneOffset;
             if (sect.used > 0) {
                 // Synchronize with what findTimeZone() found:
-                QStringView zoneName = QStringView{m_text}.mid(pos, sect.used);
+                QStringView zoneName = QStringView{m_text}.sliced(pos, sect.used);
                 Q_ASSERT(!zoneName.isEmpty()); // sect.used > 0
 
                 const QStringView offsetStr = zoneName.startsWith(QLatin1String("UTC"))
-                                             ? zoneName.mid(3) : zoneName;
+                                             ? zoneName.sliced(3) : zoneName;
                 const bool isUtcOffset = offsetStr.startsWith(QLatin1Char('+'))
                                          || offsetStr.startsWith(QLatin1Char('-'));
                 const bool isUtc = zoneName == QLatin1String("Z")
@@ -1246,8 +1246,8 @@ QDateTimeParser::scanString(const QDateTime &defaultValue, bool fixup) const
         isSet |= sn.type;
     }
 
-    if (QStringView{m_text}.mid(pos) != separators.last()) {
-        QDTPDEBUG << "invalid because" << QStringView{m_text}.mid(pos)
+    if (QStringView{m_text}.sliced(pos) != separators.last()) {
+        QDTPDEBUG << "invalid because" << QStringView{m_text}.sliced(pos)
                   << "!=" << separators.last() << pos;
         return StateNode();
     }
@@ -1625,13 +1625,13 @@ QDateTimeParser::ParsedSection QDateTimeParser::findUtcOffset(QStringView str) c
     const bool startsWithUtc = str.startsWith(QLatin1String("UTC"));
     // Get rid of UTC prefix if it exists
     if (startsWithUtc)
-        str = str.mid(3);
+        str = str.sliced(3);
 
     const bool negativeSign = str.startsWith(QLatin1Char('-'));
     // Must start with a sign:
     if (!negativeSign && !str.startsWith(QLatin1Char('+')))
         return ParsedSection();
-    str = str.mid(1);  // drop sign
+    str = str.sliced(1);  // drop sign
 
     const int colonPosition = str.indexOf(QLatin1Char(':'));
     // Colon that belongs to offset is at most at position 2 (hh:mm)
@@ -1658,7 +1658,7 @@ QDateTimeParser::ParsedSection QDateTimeParser::findUtcOffset(QStringView str) c
     str.truncate(i);  // The rest of the string is not part of the UTC offset
 
     bool isInt = false;
-    const int hours = str.mid(0, hoursLength).toInt(&isInt);
+    const int hours = str.first(hoursLength).toInt(&isInt);
     if (!isInt)
         return ParsedSection();
     const QStringView minutesStr = str.mid(hasColon ? colonPosition + 1 : 2, 2);