Commit Graph

5704 Commits (8a18466e38779b63c19e281e92031cebaedbcba5)

Author SHA1 Message Date
Ahmad Samir 93f54f0aa4 ContainerApiSymmetry: verify Qt containers member erase returns iterator
For QSet, the key_type is const, so can't test assiging to it.

Pick-to: 6.4
Change-Id: I9d363ef3fe52646b937d6a422227b19c48fdaf1f
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 21:53:02 +02:00
Mårten Nordheim e35cf5ebdc QByteArrayView: Add mid/left/right
Because they are too convenient to leave out.

Change-Id: I844cfb794ce0f575c2c65075d9051b0b878a434f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-12-02 20:53:01 +01:00
Mate Barany f192ddad8b QString: overload prepend with QUtf8StringView
Add the missing overload.

[ChangeLog][QtCore][QString] Added prepend(QUtf8StringView)
overload.

Task-number: QTBUG-103302
Change-Id: I3f74e884e514ebc0b15a13b074584d8272a02f41
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 16:04:14 +01:00
Mate Barany f046589e14 QString: overload insert with QUtf8StringView
Overloading insert is a bit tricky since the size might change after
the conversion so either the tail has to be moved twice or a temporary
buffer is needed. For now, add an ineffective but simple overload as in
the case of the const char *s overload, and do the performance
optimization in a follow-up task (QTBUG-108546).

[ChangeLog][QtCore][QString] Added insert(QUtf8StringView) overload.

Task-number: QTBUG-103302
Change-Id: If01c216ff626da29abb43eb68d4de82824f3bfba
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-12-02 16:04:11 +01:00
Mate Barany 2ffdb3bcdd QString: overload the += operator to handle QUtf8StringView
The += operator is already overloaded to handle QStringView and
QLatin1String - add the missing QUtf8StringView overload.

[ChangeLog][QtCore][QString] Added operator+=(QUtf8StringView)
overload.

Task-number: QTBUG-103302
Change-Id: Iec6940bad7866310c826a130b98accebc3c82aa8
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 16:04:06 +01:00
Mate Barany d2e1d73bf1 QString: overload append to accept QUtf8StringView
Add the missing overload, among other things it is needed to
implement QTBUG-103302.

[ChangeLog][QtCore][QString] Added append(QUtf8StringView)
overload.

Task-number: QTBUG-103302
Change-Id: I576f73c1919e3a1f1a315d0f82c708e835686eb1
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 16:04:01 +01:00
Øystein Heskestad b977ae371a Add In-place utf-8 case-insensitive comparisons
Also add optimizations for more string comparisons and add tests and
benchmarks.

[ChangeLog][QtCore][QString] Added utf-8 case-insensitive comparisons

Fixes: QTBUG-100235
Change-Id: I7c0809c6d80c00e9a5d0e8ac3ebb045cf7004a30
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-12-02 11:35:49 +01:00
Mate Barany 8c0ed7422c Refactor\Extend tst_QString::prepend_data with additional test cases
During the implementation of QString::append(QUtf8StringView) it has
become apparent that the testing is insufficient as it did not warn
about an extra growth. The following tests have been added that append:
- y-umlaut and greek letter small theta (2 UTF-8 code units => 1 UTF-16)
- devanagri letter ssa (3 UTF-8 code units => 1 UTF-16)
- chakma digit zero (4 UTF-8 code units => 2 UTF-16 code units)
- some combinations of the above

Pick-to: 6.4 6.2
Task-number: QTBUG-103302
Change-Id: I981213c296bafc81663b08c0f1f339bbd8a96485
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 10:34:52 +00:00
Mate Barany bc9e1c5c27 Refactor\Extend tst_QString::insert_data with additional test cases
During the implementation of QString::append(QUtf8StringView) it has
become apparent that the testing is insufficient as it did not warn
about an extra growth. The following tests have been added that append:
- y-umlaut and greek letter small theta (2 UTF-8 code units => 1 UTF-16)
- devanagri letter ssa (3 UTF-8 code units => 1 UTF-16)
- chakma digit zero (4 UTF-8 code units => 2 UTF-16 code units)
- some combinations of the above

Pick-to: 6.4 6.2
Task-number: QTBUG-103302
Change-Id: I3d81cf10b7eb74433ce5bea9b92ce6bce1230dcd
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 10:34:49 +00:00
Mate Barany 4e5f874063 Refactor\Extend tst_QString::append_data with additional test cases
During the implementation of QString::append(QUtf8StringView) it has
become apparent that the testing is insufficient as it did not warn
about an extra growth. The following tests have been added that append:
- y-umlaut and greek letter small theta (2 UTF-8 code units => 1 UTF-16)
- devanagri letter ssa (3 UTF-8 code units => 1 UTF-16)
- chakma digit zero (4 UTF-8 code units => 2 UTF-16 code units)
- some combinations of the above

Note that this also affects operator_pluseq_data, which is basically
a wrapper around append_data.

Pick-to: 6.4 6.2
Task-number: QTBUG-103302
Change-Id: I09ed950e3f0e71ae9ae85a455f42e130887f1109
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
2022-12-02 11:34:47 +01:00
Patrick Stewart 4fb96669e3 QBindable: Make ordinary Q_PROPERTYs bindable
Implements an adaptor from the notification signal of a Q_PROPERTY to
QBindable. The Q_PROPERTY does not need to be BINDABLE, but can still
be bound or used in a binding.

[ChangeLog][Core][Q_PROPERTY] Q_PROPERTYs without BINDABLE can be wrapped in QBindable to make them usable in bindings

Change-Id: Id0ca5444b93a371ba8720a38f3607925d393d98a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2022-11-30 21:21:03 +00:00
Fabian Kosmale cf17206a9d tst_QByteArrayLarge::initTestCase: Skip tests under ASAN
Change-Id: I0095346fed64d588940f9eddd7ce370e0fecb940
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-30 04:50:37 +01:00
Marc Mutz 39473f9210 Make XmlStringRef convertible to QAnyStringView/QStringView
Both QStringView and QAnyStringView implicitly convert from any
container with a fitting value_type, and working std::data, std::size,
std::begin and std::end.

Add these missing operations (and complementary ones) to XmlStringRef,
so it implicitly converts to QStringView and QAnyStringView, too.

Add a check to that effect and remove the now-superfluous operator
QStringView().

Task-number: QTBUG-103302
Change-Id: I89d586cf64447a82022e06d546d7ee8339fc6dc7
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2022-11-29 20:03:06 +00:00
Thiago Macieira f6f1ee63dc qfloat16: make it a built-in metatype
I've reserved the IDs for int128, uint128, bfloat16, and float128,
because the mask in qvariant.cpp's qIsNumericType() requires primitives
to be less than 64 to operate properly.

Added a QMetaType/QDataStream test to confirm it is indeed built-in.

Change-Id: I3d74c753055744deb8acfffd17247f7f57bada02
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
2022-11-28 10:59:35 -08:00
Thiago Macieira 5838074912 qfloat16: add QTextStream & QDebug streaming operators
Change-Id: Ieba79baf5ac34264a988fffd172655bdcaf12a59
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
2022-11-28 10:59:34 -08:00
Thiago Macieira c53bf1b45e qfloat16: add QDataStream tests
Change-Id: I3d74c753055744deb8acfffd172494bf935864b8
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
2022-11-28 10:59:31 -08:00
Thiago Macieira 99c7f0419e qfloat16: add support for native _Float16 (C2x extended floating point)
The C++ equivalent is std::float16_t, defined in P1467[1], and is coming
with GCC 13 both in native mode (for x86, using AVX512FP16) and in
emulated mode. The C and C++ types will be the same type (<stdfloat>
simply typedefs).

qfloat16 will need to remain a wrapper with an integer member to keep
ABI with previous Qt versions. Because it is a trivially-copyable small
type, it gets currently passed in registers; the presence of the integer
member means it gets passed in general-purpose registers, while a single
_Float16 member would be passed in a floating-point register. See:
https://gcc.godbolt.org/z/8fEendjff

[1] https://wg21.link/p1467

Change-Id: I8a5b6425b64a4e319b94fffd161be56397cb48e6
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
2022-11-28 10:59:20 -08:00
Marc Mutz 5812c36cd5 tst_QStringApiSymmetry: add checks for QByteArrayView
... where checks for QByteArray existed before.

The checks we can't add are
- left/right/mid (legacy APIs not implemented in QBAV)
- several relational operators, d/t ambiguities. Created
  QTBUG-108805 to track these.

Task-number: QTBUG-108805
Pick-to: 6.4 6.2
Change-Id: I30cc9b29a228d69d32af51234f2c28221478a75c
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
2022-11-27 17:14:28 +01:00
Marc Mutz d1a37ab099 tst_QString: check empty regex can replace in empty/null string
It's not intuitive, so check lest people break it.

Pick-to: 6.4 6.2
Change-Id: I2435cd69be7b77a6ae59cdc7b5fb99658cfc42fd
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-27 17:14:28 +01:00
Ulf Hermann 6aa02bdeaf QLocale: Have qstrntod() return end of parsed string also on underflow
Underflows should be treated the same as overflows.

Fixes: QTBUG-108628
Change-Id: I23aa7bbe1d103778cefca08bd3e584e72f306583
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
2022-11-25 10:55:39 +01:00
Edward Welbourne 6c435e5dd4 Restore end-of-parse reporting to qstrntod()
Rework QSimpleParsedNumber to store a qsizetype whose sign serves as
ok flag (positive is ok, zero and negative are not) and magnitude is
the number of characters used. This replaces an endptr that was set to
null to indicate !ok, but that deprived us of end-of-parse
information, which is needed for number-parsing. In particular, JS's
parsing of numbers accepts overflow (where qstrntod() flags it as
invalid) as infinity; so qstrntod() does need to say how long the
overflowing (but JS-valid, none the less) number-text was.

Modify all callers of functions using this (recently-introduced) type
and add tests that fail without this fix.

Fixes: QTBUG-108628
Change-Id: I416cd213e1fb8101b1af5a6d43615b970a5db9b4
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
2022-11-24 10:06:53 +01:00
Marc Mutz 0786405857 tst_QMap: remove unused std::as_const clone
Amends d273076b44.

Pick-to: 6.4 6.2
Change-Id: Icfff438223ed10756f15e25ea52cccdf93dd47a2
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
2022-11-18 18:02:21 +01:00
Ahmad Samir d9637d0781 QString: don't detach in removeStringImpl()
- If this string is not shared, modify it directly
- If this string is shared, instead of detaching copy the characters
  from this string, except the ones that are going to be removed, to a
  new string and swap it. This is more efficient than detaching, which
  would copy the whole string including the characters that are going
  to be removed.

This affects:
remove(const QString &str, Qt::CaseSensitivity cs)
remove(QLatin1StringView str, Qt::CaseSensitivity cs)

Adjust the unittests to test both code paths.

[ChangeLog][QtCore][QString] Improved the performance of
QString::remove() by avoiding unnecessary data copying. Now, if this
string is (implicitly) shared with another, instead of copying
everything and then removing what we don't want, the characters from
this string are copied to the destination, except the ones that need to
be removed.

Task-number: QTBUG-106181
Change-Id: Id8eba59a44bab641cc8aa662eb45063faf201183
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-17 02:15:28 +00:00
Ahmad Samir d27360818d QString: add unittest to verify erase() returns a QString::iterator
Not a const_iterator.

Change-Id: I0a9db7cdd956541e0be6e748b084b502fcc1e563
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-17 04:15:28 +02:00
Ahmad Samir 4d84843822 QString, QByteArray: add removeAt/First/Last() convenience methods
Requested in codereview.qt-project.org/c/qt/qtbase/+/441770

[ChangeLog][QtCore][Text] Add removeAt/First/Last() convenience methods to
QString and QByteArray

Change-Id: I48a803e456e70cc51d51726a5e3aa7c125aedb1c
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-16 18:25:35 +02:00
Edward Welbourne da5dd84858 Add more tests of QLocale and "single character" data that aren't
This tests that strings using the first Unicode code-point of such a
multi-character token don't get recognized as "valid" number strings.
This would catch an implementation issue if the parsing code
mistakenly matched against only the first code-point of each "single
character" token.

It also adds tests of integer formatting, with multi-character sign,
and reworks some QStringView().toString()s to use u"..."_s.

Task-number: QTBUG-107801
Change-Id: I7b868ce2955bb322b3ecfc200438a21437090a0c
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-11 16:32:53 +01:00
Johannes Kauffmann c958e5daf1 tests: fix build with -no-feature-concurrent
Pick-to: 6.2 6.4
Change-Id: I91602931bfb63e7d6659599a26e00e0bc4f854ab
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2022-11-09 20:33:49 +01:00
Thiago Macieira 64dc886db7 tst_QVariant: convert some test functions to table-driven
Most of them were easy to change. The pair one was a bit of a stretch,
but still worked. I've removed the lines on QPair, since QPair is
std::pair in Qt 6.

Change-Id: I3d74c753055744deb8acfffd17246ec98c583d08
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2022-11-09 04:05:50 -07:00
Thiago Macieira bdc8778d7a QVariant: add support for numeric comparisons for char16_t and char32_t
Change-Id: I3d74c753055744deb8acfffd17248af45fd20556
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2022-11-09 04:05:50 -07:00
Thiago Macieira cf0a1c2e51 QVariant: fix comparison of enums to numerics
qIsNumericType does not return true for enum types, which meant we never
called numericCompare() or numericEquals() when one of the types was an
enum.

Task-number: QTBUG-108188
Change-Id: I3d74c753055744deb8acfffd172449c68af19367
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2022-11-09 04:05:50 -07:00
Thiago Macieira 393d5efda3 QVariant: make a major simplification in the numeric comparison
The code implementing the C++ rules of type promotion and conversion
was too pedantic. There's no need to follow the letter of the standard,
not when we can now assume that everything is two's complement (this was
true for all architectures we supported when I wrote this code in 2014,
but wasn't required by the standard).

So we can reduce this to fewer comparisons and fewer rules, using the
size of the type, not just the type ID.

Change-Id: I3d74c753055744deb8acfffd172446b02444c0c0
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2022-11-09 04:05:50 -07:00
Samuel Mira d53ea82950 Android: Fix incorrect fullscreen dimensions
The insets used to calculate the correct height were not the best
choice. It used display cutout insets which would work correctly on
most devices, but in the case of an emulator or a device without a
camera, it could fail to calculate correctly.

Task-number: QTBUG-107604
Task-number: QTBUG-107709
Task-number: QTBUG-107523
Pick-to: 6.4 6.4.1 6.2 5.15
Change-Id: I8c4da83ae7359a0c133dbeb02dbd2cd260565f78
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>
2022-11-07 09:06:34 +00:00
Thiago Macieira f642bdf69e QByteArray: move the high-memory-using and slot tests away
Otherwise, tst_QByteArray takes 97 seconds on my laptop to run. Makes
design iteration difficult.

Pick-to: 6.4
Change-Id: I07ec23f3cb174fb197c3fffd17220e6737907415
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
2022-11-05 11:15:40 -07:00
Ahmad Samir 7000e2dd5c QByteArray: add erase() unittests
Basic unitttest and one to verify erase returns iterator, not
const_iterator.

Change-Id: I44c3b82b4686ff3809648063376f5e36fb7e181d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-04 09:32:01 +02:00
Ahmad Samir b8b675014f QString: don't detach in remove(QChar ch, Qt::CaseSensitivity cs)
- If the string isn't shared, don't call detach(), instead remove characters
  matching ch, and resize()
- If the string is shared, create a new string, and copy all characters
  except the ones that would be removed, see task for details

Update unittets so that calls to this overload of remove() test both code
paths (replace() calls remove(QChar, cs) internally).

Drive-by change: use QCOMPARE() instead of QTEST()

Task-number: QTBUG-106181
Change-Id: I1fa08cf29baac2560fca62861fc4a81967b54e92
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-04 03:06:30 +02:00
Ahmad Samir 358b7a9e74 QByteArray: don't detach in remove()
- If this bytearray isn't shared call d->erase() as needed
- if it's shared, instead of detaching, create a new bytearray, and copy
  all characters except for the ones that would be removed

See task for details.

Adjust unittest to test both code paths.

Task-number: QTBUG-106182
Change-Id: I806e4d1707004345a2472e056905fbf675f765ab
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-04 03:06:29 +02:00
Marc Mutz 1c6bf3e09e Port from container::count() and length() to size() - V5
This is a semantic patch using ClangTidyTransformator as in
qtbase/df9d882d41b741fef7c5beeddb0abe9d904443d8, but extended to
handle typedefs and accesses through pointers, too:

    const std::string o = "object";

    auto hasTypeIgnoringPointer = [](auto type) { return anyOf(hasType(type), hasType(pointsTo(type))); };

    auto derivedFromAnyOfClasses = [&](ArrayRef<StringRef> classes) {
        auto exprOfDeclaredType = [&](auto decl) {
            return expr(hasTypeIgnoringPointer(hasUnqualifiedDesugaredType(recordType(hasDeclaration(decl))))).bind(o);
        };
        return exprOfDeclaredType(cxxRecordDecl(isSameOrDerivedFrom(hasAnyName(classes))));
    };

    auto renameMethod = [&] (ArrayRef<StringRef> classes,
                            StringRef from, StringRef to) {
        return makeRule(cxxMemberCallExpr(on(derivedFromAnyOfClasses(classes)),
                            callee(cxxMethodDecl(hasName(from), parameterCountIs(0)))),
                        changeTo(cat(access(o, cat(to)), "()")),
                        cat("use '", to, "' instead of '", from, "'"));
    };

    renameMethod(<classes>, "count", "size");
    renameMethod(<classes>, "length", "size");

except that the on() matcher has been replaced by one that doesn't
ignoreParens().

a.k.a qt-port-to-std-compatible-api V5 with config Scope: 'Container'.

Added two NOLINTNEXTLINEs in tst_qbitarray and tst_qcontiguouscache,
to avoid porting calls that explicitly test count().

Change-Id: Icfb8808c2ff4a30187e9935a51cad26987451c22
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
2022-11-03 14:59:24 +01:00
Ahmad Samir f41089ba3d QString: don't detach in remove(pos, len)
- If this string isn't shared, don't call detach, instead use ->erase() as
  needed
- If this string is shared, create a new string, and copy all elements
  except the ones that would be removed, see task for details

Update unittest to test both code paths.

Task-number: QTBUG-106181
Change-Id: I4c73ff17a6fa89ddcf6966f9c5bf789753f6d39e
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-03 14:22:51 +02:00
Ahmad Samir dcfab7e28e QString, QByteArray: add erase(iterator) method
Fixes: QTBUG-106182
Change-Id: Idc74cc643b90252838ca1a9ca40a330315da421f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-03 14:22:51 +02:00
Marc Mutz 8acec4dbe6 Long live QUtf8::convertFromLatin1()!
With the introduction of QAnyStringView, overloading based on UTF-8
and Latin-1 is becoming more common. Often, the two overloads can
share the processing backend, because we're only interested in the
US-ASCII subset of each.

But if they can't, we need a faster way to convert L1 into UTF-8 than
going via UTF-16. This is where the new private API comes in.

Eventually, we should have the converse operation, too, to complete
the set of direct conversions between the possible three
QAnyStringView encodings L1/U8/U16, but this direction is easier to
code (there are no error cases) and more immediately useful, so
provide L1->U8 alone for now.

Change-Id: I3f7e1a9c89979d0eb604cb9e42dedf3d514fca2c
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-02 17:21:28 +01:00
Ahmad Samir 96f7404b54 QFileInfo: add unittest for setFileTime()
Borrowed from tst_qtemporaryfile with some changes.

Change-Id: I596ddd0ac8dbe10edd63e481198064dcec15d3e6
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-01 21:33:15 +02:00
Giuseppe D'Angelo fb4bc5fa26 QHash: tame HasQHashSingleArgOverload ODR violations
qhashfunctions.h defines a catch-all 2-arguments qHash(T, seed)
in order to support datatypes that implement a 1-argument overload
of qHash (i.e. qHash(Type)). The catch-all calls the 1-argument
overload and XORs the result with the seed.

The catch-all is constrained on the existence of such a 1-argument
overload. This is done in order to make the catch-all SFINAE-friendly;
otherwise merely instantiating the catch-all would trigger a hard error.
Such an error would make it impossible to build a type trait that
detects if one can call qHash(T, size_t) for a given type T.

The constraint itself is called HasQHashSingleArgOverload and lives in a
private namespace.

It has been observed that HasQHashSingleArgOverload misbehaves for
some datatypes. For instance, HasQHashSingleArgOverload<int> is actually
false, despite qHash(123) being perfectly callable. (The second argument
of qHash(int, size_t) is defaulted, so the call *is* possible.)

--

Why is HasQHashSingleArgOverload<int> false?

This has to do with how HasQHashSingleArgOverload<T> is implemented: as
a detection trait that checks if qHash(declval<T>()) is callable.

The detection itself is not a problem. Consider this code:

  template <typename T>
    constexpr bool HasQHashSingleArgOverload = /* magic */;

  class MyClass {};
  size_t qHash(MyClass);

  static_assert(HasQHashSingleArgOverload<MyClass>); // OK

Here, the static_assert passes, even if qHash(MyClass) (and MyClass
itself) were not defined at all when HasQHashSingleArgOverload was
defined.

This is nothing but 2-phase lookup at work ([temp.dep.res]): the
detection inside HasQHashSingleArgOverload takes into account the qHash
overloads available when HasQHashSingleArgOverload was declared, as well
as any other overload declared before the "point of instantiation". This
means that qHash(MyClass) will be visible and detected.

Let's try something slightly different:

  template <typename T>
    constexpr bool HasQHashSingleArgOverload = /* magic */;

  size_t qHash(int);

  static_assert(HasQHashSingleArgOverload<int>); // ERROR

This one *does not work*. How is it possible? The answer is that 2-phase
name lookup combines the names found at definition time with the names
_found at instantiation time using argument-dependent lookup only_.
`int` is a fundamental type and does not participate in ADL. In the
example, HasQHashSingleArgOverload has actually no qHash overloads to
even consider, and therefore its detection fails.

You can restore detection by moving the declaration of the qHash(int)
overload *before* the definition of HasQHashSingleArgOverload, so it's
captured at definition time:

  size_t qHash(int);

  template <typename T>
    constexpr bool HasQHashSingleArgOverload = /* magic */;

  static_assert(HasQHashSingleArgOverload<int>); // OK!

This is why HasQHashSingleArgOverload<int> is currently returning
`false`: because HasQHashSingleArgOverload is defined *before* all the
qHash(fundamental_type) overloads in qhashfunctions.h.

--

Now consider this variation of the above, where we keep the qHash(int)
overload after the detector (so, it's not found), but also prepend an
Evil class implicitly convertible from int:

  struct Evil { Evil(int); };
  size_t qHash(Evil);

  template <typename T> constexpr bool HasQHashSingleArgOverload = /* magic */;

  size_t qHash(int);

  static_assert(HasQHashSingleArgOverload<int>); // OK

Now the static_assert passes. HasQHashSingleArgOverload is still not
considering qHash(int) (it's declared after), but it's considering
qHash(Evil). Can you call *that* one with an int? Yes, after a
conversion to Evil.

This is extremely fragile and likely an ODR violation (if not ODR, then
likely falls into [temp.dep.candidate/1]).

--

Does this "really matter" for a type like `int`? The answer is no. If
HasQHashSingleArgOverload<int> is true, then a call like

  qHash(42, 123uz);

will have two overloads in its overloads set:

1) qHash(int, size_t)
2) qHash(T, size_t), i.e. the catch-all template. To be pedantic,
qHash<int>(const int &, size_t), that is, the instantiation of the
catch-all after template type deduction for T (= int)
([over.match.funcs.general/8]).

Although it may look like this is ambiguous as both calls have perfect
matches for the arguments, 1) is actually a better match than 2) because
it is not a template specialization ([over.match.best/2.4]).

In other words: qHash(int, size_t) is *always* called when the argument
is `int`, no matter the value of HasQHashSingleArgOverload<int>. The
catch-all template may be added or not to the overload set, but it's
a worse match anyways.

--

Now, let's consider this code:

  enum MyEnum { E1, E2, E3 };
  qHash(E1, 42uz);

This code compiles, although we do not define any qHash overload
specifically for enumeration types (nor one is defined by MyEnum's
author).

Which qHash overload gets called?  Again there are two possible
overloads available:

1) qHash(int, size_t). E1 can be converted to `int` ([conv.prom/3]),
and this overload selected.

2) qHash(T, size_t), which after instantiation, is qHash<MyEnum>(const
MyEnum &, size_t).

In this case, 2) is a better match than 1), because it does not require
any conversion for the arguments.

Is 2) a viable overload? Unfortunately the answer here is "it depends",
because it's subject to what we've learned before: since the catch-all
is constrained by the HasQHashSingleArgOverload trait, names introduced
before the trait may exclude or include the overload.

This code:

  #include <qhashfunctions.h>

  enum MyEnum { E1, E2, E3 };
  qHash(E1, 42uz);
  static_assert(HasQHashSingleArgOverload<MyEnum>); // ERROR

will fail the static_assert. This means that only qHash(int, size_t) is
in the overload set.

However, this code:

  struct Evil { Evil(int); };
  size_t qHash(Evil);

  #include <qhashfunctions.h>

  enum MyEnum { E1, E2, E3 };
  qHash(E1, 42uz);
  static_assert(HasQHashSingleArgOverload<MyEnum>); // OK

will pass the static_assert. qHash(Evil) can be called with an object of
type MyEnum after an user-defined conversion sequence
([over.best.ics.general], [over.ics.user]: a standard conversion
sequence, made of a lvalue-to-rvalue conversion + a integral promotion,
followed by a conversion by constructor [class.conv.ctor]).
Therefore, HasQHashSingleArgOverload<MyEnum> is true here; the catch-all
template is added to the overload set; and it's a best match for the
qHash(E1, 42uz) call.

--

Is this a problem? **Yes**, and a huge one: the catch-all template does
not yield the same value as the qHash(int, size_t) overload. This means
that calculating hash values (e.g. QHash, QSet) will have different
results depending on include ordering!

A translation unit TU1 may have

  #include <QSet>
  #include <Evil>

  QSet<MyEnum> calculateSet { /* ... */ }

And another translation unit TU2 may have

  #include <Evil>
  #include <QSet> // different order

  void use() {
    QSet<MyEnum> set = calculateSet();
  }

And now the two TUs cannot exchange QHash/QSet objects as they would
hash the contents differently.

--

`Evil` actually exists in Qt. The bug report specifies QKeySequence,
which has an implicit constructor from int, but one can concoct infinite
other examples.

--

Congratulations if you've read so far.

=========================
=== PROPOSED SOLUTION ===
=========================

1) Move the HasQHashSingleArgOverload detection after declaring the
overloads for all the fundamental types (which we already do anyways).
This means that HasQHashSingleArgOverload<fundamental_type> will now
be true. It also means that the catch-all becomes available for all
fundamental types, but as discussed before, for all of them we have
better matches anyways.

2) For unscoped enumeration types, this means however an ABI break: the
catch-all template becomes always the best match. Code compiled before
this change would call qHash(int, size_t), and code compiled after this
change would call the catch-all qHash<Enum>(Enum, size_t); as discussed
before, the two don't yield the same results, so mixing old code and new
code will break.

In order to restore the old behavior, add a qHash overload for
enumeration types that forwards the implementation to the integer
overloads (using qToUnderlying¹).

(Here I'm considering the "old", correct behavior the one that one gets
by simply including QHash/QSet, declaring an enumeration and calling
qHash on it. In other words, without having Evil around before including
QHash.)

This avoids an ABI break for most enumeration types, for which one
does not explicitly define a qHash overload. It however *introduces*
an ABI break for enumeration types for which there is a single-argument
qHash(E) overload. This is because

- before this change, the catch-all template was called, and that
in turn called qHash(E) and XOR'ed the result with the seed;
- after this change, the newly introduced qHash overload for
enumerations gets called. It's very likely that it would not give
the same result as before.

I don't have a solution for this, so we'll have to accept the ABI
break.

Note that if one defines a two-arguments overload for an enum type,
then nothing changes there (the overload is still the best match).

3) Make plans to kill the catch-all template, for Qt 7.0 at the latest.
We've asked users to provide a two-args qHash overload for a very long
time, it's time to stop working around that.

4) Make plans to switch from overloading qHash to specializing std::hash
(or equivalent). Specializations don't overload, and we'd get rid of
all these troubles with implicit conversions.

--

¹ To nitpick, qToUnderlying may select a *different* overload than
the one selected by an implicit conversion.

That's because an unscoped enumeration without a fixed underlying type
is allowed to have an underlying type U, and implicitly convert to V,
with U and V being two different types (!).

U is "an integral type that can represent all the enumerator values"
([dcl.enum/7]). V is selected in a specific list in a specific order
([conv.prom]/3). This means that in theory a compiler can take enum E {
E1, E2 }, give it `unsigned long long` as underlying type, and still
allow for a conversion to `int`.

As far as I know, no compiler we use does something as crazy as that,
but if it's a concern, it needs to be fixed.

[ChangeLog][Deprecation Notice] Support for overloads of qHash with only
one argument is going to be removed in Qt 7. Users are encouraged to
upgrade to the two-arguments overload. Please refer to the QHash
documentation for more information.

[ChangeLog][Potentially Binary-Incompatible Changes] If an enumeration
type for which a single-argument qHash overload has been declared is
being used as a key type in QHash, QMultiHash or QSet, then objects of
these types are no longer binary compatible with code compiled against
an earlier version of Qt. It is very unlikely that such qHash overloads
exist, because enumeration types work out of the box as keys Qt
unordered associative containers; users do not need to define qHash
overloads for their custom enumerations. Note that there is no binary
incompatibity if a *two* arguments qHash overload has been declared
instead.

Fixes: QTBUG-108032
Fixes: QTBUG-107033
Pick-to: 6.2 6.4
Change-Id: I2ebffb2820c553e5fdc3a341019433793a58e3ab
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-11-01 01:52:13 +02:00
Johannes Kauffmann a9fa999f79 tests: fix configuring with -no-feature-gui
Pick-to: 6.2 6.4
Change-Id: I99765d38c9c37f1fe17b15f7736e4c78c7ffac20
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2022-10-29 01:04:09 +02:00
Thiago Macieira b56b77b68a QOperatingSystemVersion: add tests for the globals
Task-number: QTBUG-107907
Pick-to: 6.4
Change-Id: I07ec23f3cb174fb197c3fffd1721a85112010ec9
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
2022-10-28 14:42:40 -07:00
Edward Welbourne 429ad095b2 Add tests of QLocale verifying some "single-characters" aren't
Some of the entries in QLocale's single_character_data[] table are
not, in fact, single characters; some RTL languages include
bidi-markers in some of the fields, some locales use some denotation
of "times ten to the power" as the exponent separator. There may be
further complications, but let's just get some tests in that verify we
are correctly serializing numbers in these locales. Include some
parsing tests to show that we are indeed failing them.

Task-number: QTBUG-107801
Change-Id: Iab9bfcea5fdcfcb991451920c9531e0e67d02913
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Ievgenii Meshcheriakov <ievgenii.meshcheriakov@qt.io>
2022-10-28 23:42:39 +02:00
Thiago Macieira bdee2c9760 QString::asprintf: fix handling of a present-but-empty precision
%.f should be handled like %.0f. You probably don't want it for strings,
though.

Fixes: QTBUG-107991
Pick-to: 6.2 6.4
Change-Id: I07ec23f3cb174fb197c3fffd1721a941fbcf15e1
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
2022-10-28 14:42:39 -07:00
Thiago Macieira bfd8463f4d QOperatingSystemVersion: fix ABI problem with dllimport on Windows
I'm not entirely sure whether this is a toolchain bug or if this is
intended. This commit ODR-uses all the static inline variables in
QOperatingSystemVersion so they are added to the list of exported
symbols in QtCore.

On Windows:

$ objdump -p bin/Qt6Core.dll | grep Windows11E
        [2534] _ZN23QOperatingSystemVersion9Windows11E

On Linux:

$ eu-readelf --dyn-syms lib/libQt6Core.so | grep Windows11E
 1985: 0000000000575430     16 OBJECT  GNU_UNIQUE PROTECTED     18 _ZN23QOperatingSystemVersion9Windows11E@@Qt_6

Pick-to: 6.4
Change-Id: Ia317fd249bcd80dbd02c198803a3a61178c0c219
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
2022-10-28 09:41:17 -07:00
Yuhang Zhao 32774f13d9 QWinRegistryKey: Fix how we handle the default value, take 2
It seems the value name correction is not needed at all,
and we must not do such correction.

Amends commit 738e05a55a

Task-number: QTBUG-107794
Change-Id: I903a762aafab4b55275beb8438e6769285821567
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
2022-10-28 09:27:13 +00:00
Thiago Macieira c2445aeadb tst_QFile: remove unused variable on Windows
Removes a warning in the build.

Pick-to: 6.4
Change-Id: I07ec23f3cb174fb197c3fffd17215c40b40333cb
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
2022-10-25 18:33:14 -07:00
Ahmad Samir 997713283e QFile: remove unconditional QTest::qWait calls
The whole unittest still passes on my machine.

Before:
tests/auto/corelib/io/qfile/tst_qfile    =  19.30 sec*proc (1 test)

After:
tests/auto/corelib/io/qfile/tst_qfile    =   4.28 sec*proc (1 test)

Change-Id: I46fd51abeaecacd44cac1c56e76871fde2a44a52
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
2022-10-25 21:18:17 +02:00