Having already caught some bugs in real code because of unchecked calls
to QFile::open, this commit marks QFile::open (and open() in other
file-I/O classes) as [[nodiscard]].
Since it's going to raise warnings, the plan is to keep the existing
behavior up to and including the next LTS. Then the warnings will switch
on by default. All of this is protected by system of macros to opt-in or
opt-out the behavioral change at any time.
A possible counter-argument for doing this is that QFile::open is also
used for opening files in the the resource system, and that opening
"cannot fail". It clearly can, if the resource is moved away or renamed;
code should at a minimum use a Q_ASSERT in debug builds. Another
counter-argument is the opening of file handles or descriptors; but
again, that opening may fail in case the handle has been closed or if
the flags are incompatible.
---
Why not marking *every* open() override? Because some are not meant to
be called directly -- for instance sockets are supposed to be open via
calls to `connectToHost` or similar.
One notable exception is QIODevice::open() itself. Although rarely
called directly by user code (which just calls open() on a specific
subclass, which likely has an override), it may be called:
1) By code that just takes a `QIODevice *` and does something with it.
That code is arguably more rare than code using QFile directly.
Still, being "generic" code, they have an extra responsibility when
making sure to handle a possible opening failure.
2) By QIODevice subclasses, which are even more rare. However, they
usually ignore the return from QIODevice::open() as it's
unconditionally true. (QIODevice::open() doesn't use the protected
virtual pattern.)
I'll try and tackle QIODevice in a future commit.
[ChangeLog][QtCore][QFileDevice] The open() functions of file-related
I/O classes (such as QFile, QSaveFile, QTemporaryFile) can now be marked
with the "nodiscard" attribute, in order to prevent a category of bugs
where the return value of open() is not checked and the file is then
used. In order to avoid warnings in existing code, the marking can be
opted in or out, by defining QT_USE_NODISCARD_FILE_OPEN or the
QT_NO_USE_NODISCARD_FILE_OPEN macros. By default, Qt will automatically
enable nodiscard on these functions starting from Qt 6.10.
Change-Id: Ied940e1c0a37344f5200b2c51b05cd1afcb2557d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
All file under doc/snippet should be
license as Documentation snippets
and according to QUIP-18 [1]
this is LicenseRef-Qt-Commercial OR BSD-3-Clause
[1]: https://contribute.qt-project.org/quips/18
Pick-to: 6.7
Task-number: QTBUG-121787
Change-Id: I76eedfb6b15c4091f726a5652e3530001d7cdaf7
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Upcoming changes to QDoc require API entities to be fully qualified;
previously, QDoc maintained a list of 'open namespaces' that were
part of matching the documented entity with its declaration, but
that concept does not work for parallelized parsing where the order
of processing can be arbitrary.
Change-Id: I18dbe83716831451ef02153b24e94a70c3cf87a7
Reviewed-by: Luca Di Sera <luca.disera@qt.io>
The docs claim that QThreadPool always creates at least one thread.
However, the user can (usually by mistake) request zero or a negative
number of threads.
The maxThreadCount() function is simply returning the value, that was
requested by the user.
Since it's a public API, it is used in several places in QtConcurrent,
where it is assumed that the value is always positive. This can lead
to a crash if the user sets zero as a maxThreadCount.
Update all such places with std::max(maxThreadCount(), 1).
Prefer this approach over changing the return value of
maxThreadCount(), because its behavior is documented and tested.
Amends 885eff0537.
Fixes: QTBUG-120335
Pick-to: 6.7 6.6 6.5 6.2
Change-Id: Id3b2087cec7fbc7a2d42febca6586f2dacffe444
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Upcoming changes to QDoc require accurate definition for
template arguments in \fn commands.
Task-number: QTBUG-118080
Change-Id: Ia905211d2b2bc5b49e5f9b50f2407544e939779d
Reviewed-by: Luca Di Sera <luca.disera@qt.io>
Remove or replace links to examples that were removed or moved under
manual tests.
Replace code snippets that were quoting the now-missing examples.
Fix documentation of QSet::removeIf().
Fix typo in documentation macro: Unknown command '\examplecateogry'.
Add qtopengl, qtshadertools dependencies to Qt Widgets documentation
project to enable correct linking to those topics.
Mark all documentation sets in qtbase as free of warnings.
Pick-to: 6.6 6.5
Change-Id: I058cd5f2063aa933ea310bceff906f05422a7cb2
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
The latter is a better choice if you don't need the result QFuture.
Describe the QThreadPool::start() overload in prose, since the
signature changed in 6.6 from std::function<void()> to Callable
auto&&. The chosen wording is compatible with both.
Pick-to: 6.6 6.5 6.2 5.15
Fixes: QTBUG-111875
Change-Id: I9f67c2f7e4b221602bf1c35b72e5d38898a4f0c9
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Use the new Q_NODISCARD_X macro to point users that ignore the QFuture
returned from QtConcurrent::run() to QThreadPool::start(), which does
the same thing, but doesn't return a future, so is better suited for
the fire-and-forget use-case the OP of and commentators on
QTBUG-111875 cited.
Can't pick to older branches, since Q_NODISCARD_X is 6.7+.
Task-number: QTBUG-111875
Change-Id: If0bf920ecc0fb59b9a9a9931ea9dc30f7abff1b7
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Rewritten to be a bit simpler, added a few more yield/YieldProcessor
alternatives, added RISC-V support.
[ChangeLog][QtCore] Added qYieldCpu() function.
Fixes: QTBUG-103014
Change-Id: I53335f845a1345299031fffd176f59032e7400f5
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
It's clean now, keep it as such.
Enabling it for QtCore is still OK, because it just hides a function
template declared in a header.
Change-Id: I8e7dfae179732ba04241a6a3258c2d722e8259df
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The most common limit for the maximum number of allowed documentation
warnings is zero. Use a global value for 'warninglimit', adopted by
all Qt module documentation projects that include the configuration
from qtbase/doc/global.
This allows for a temporary increase of the limit across all modules as
needed - for example, when updating the QDoc binary that the CI
provisions to a version that introduces new types of documentation
warnings.
Increase this base limit temporarily to 10 to help re-enable
documentation testing in CI as it's currently disabled.
Task-number: QTBUG-113326
Change-Id: I8b66951ca9324bcfaec3b5a7ec2cff544c62feb0
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
A number of users have explored the behavior and complained about it.
Lets add a \note explaining this. The function in charge is
QThreadPool::stealAndRunRunnable(QRunnable *), which is a private
function, exclusively used by:
QFutureInterfaceBase::waitForResult()
QFutureInterfaceBase::waitForFinished()
also update the documentation to reflect these changes accordingly.
Fixes: QTBUG-112351
Pick-to: 6.6 6.5 6.2 5.15
Change-Id: I839858cb449063d8af9bef64d2f35a6816a419b0
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
If we have a rvalue reference to an unshared QVariant, we can avoid
potentially expensive copies, and use move semantics instead.
[ChangeLog][QtCore][QVariant] Added rvalue QVariant overloads of qvariant_cast<T>() and QVariant::value<T>().
[ChangeLog][Potentially Source-Incompatible Changes][QVariant] It is no
longer possible to take the address of a specialization of
qvariant_cast; consider using a lambda function instead.
Change-Id: Ifc74991eadcc31387b755c45484224a3200bb0ba
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Creating a continuation with QtFuture::Launch::Async policy does not
work well with the example, because it still needs to update the UI
once the async continuation is finished. If the user decides to
close the application while the async continuation is executed,
the next continuation will be accessing data from the destroyed
Images object.
Fix it by using QtConcurrent::run() to do the "heavy" work in a
separate thread, and use a QFutureWatcher to handle the results of
the async execution. Update the example documentation accordingly.
After this patch the example still shows the usage of continuations
and onCanceled()/onFailed() handlers. However, it now does not
illustrate the usage of different launch policies and continuation
contexts. It might not be a big issue, because the QFuture
documentation describes these topics rather extensively.
Fixes: QTBUG-103514
Pick-to: 6.5
Change-Id: I8142535064ff7a4e8007a5c0a8fe7709d6d942ec
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
MSVC warns due to assignment of std::distance's return value (__int64)
to int when warning C4244 is enabled.
Pick-to: 6.5
Change-Id: I78360ec1bbe861b96d6875af3a29b77f419a3843
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
The QtConcurrent examples were only discoverable from the
"All Qt Examples" page, which was very inconvenient.
This patch adds a separate page for all Qt Concurrent examples, and
links to it from the module's main page.
Pick-to: 6.5
Change-Id: Iecabd9e21033605c1ec74232ce4f3d68b0c78d82
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Jaishree Vyas <jaishree.vyas@qt.io>
To allow the user to customize the C++ code that QDoc sees, so as to be
able to work-around some limitations on QDoc itself, QDoc defines two
symbols: Q_QDOC and Q_CLANG_QDOC, both of which are "true" during an
entire execution of QDoc.
At a certain point in time, QDoc allowed the user the choice between a
custom C++ parser and a Clang based one.
The Q_QDOC symbol would always be defined while the Q_CLANG_QDOC symbol
would be defined only when the Clang based parser was chosen.
In more recent times, QDoc always uses a Clang based parser, such that
both Q_CLANG_QDOC and Q_QDOC are always defined, making them equivalent.
To avoid using different symbols, and the possible confusion and
fragmentation that derives from it, all usages of Q_CLANG_QDOC are now
replaced by the equivalent usages of Q_QDOC.
Change-Id: I5810abb9ad1016a4c5bbea99acd03381b8514b3f
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
CMakeLists.txt and .cmake files of significant size
(more than 2 lines according to our check in tst_license.pl)
now have the copyright and license header.
Existing copyright statements remain intact
Task-number: QTBUG-88621
Change-Id: I3b98cdc55ead806ec81ce09af9271f9b95af97fa
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
resultsMapSize is modified inside the runReduce() method, and the
writes are protected via mutex lock. However, reads of resultsMapSize
through shouldThrottle()/shouldStartThread() (that can be called by
multiple threads) are done without a lock. Added the missing locks.
Task-number: QTBUG-104787
Pick-to: 6.4 6.3 6.2 5.15
Change-Id: I700e7b66e67025bc7f570bc8ad69409b82675049
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
This makes header files self-contained and reduces the number of
'sources of truth' for syncqt procedure.
Change-Id: I7f5865abc69934603139d23e1b5452da46ccb110
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
QtConcurrent map- and filter-reduce functions take an initial value,
which can be of any type that is convertable to the result type. The
side-effect of this is that the enum values passed as ReduceOptions can
be treated as an initial value (if they are convertable to the result
type) which will result into a wrong overload call. To avoid this, added
additional check to make sure that the initial value type doesn't match
with ReduceOption enum.
Note that this required including the qtconcurrentreducekernel.h header
in qtconcurrentfunctionwrappers.h (which contains compiler checks for
QtConcurrent) for accessing ReduceOption enum, so I had to get rid of
qtconcurrentfunctionwrappers.h include from qtconcurrentreducekernel.h
to avoid circular header includes. This, in turn, required moving the
QtPrivate::SequenceHolder helper type to qtconcurrentreducekernel.h,
which didn't belong to qtconcurrentfunctionwrappers.h anyway.
Pick-to: 6.3 6.2
Fixes: QTBUG-102999
Change-Id: Ieaa8ef2e4bd82ce2ada2e0af9a47b87b51d59e87
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Replace the current license disclaimer in files by
a SPDX-License-Identifier.
Files that have to be modified by hand are modified.
License files are organized under LICENSES directory.
Task-number: QTBUG-67283
Change-Id: Id880c92784c40f3bbde861c0d93f58151c18b9f1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
cf043a785a unified QtConcurrent::run() and
QtConcurrent::runWithPromise(). Remove the last mentions of
runWithPromise. Also did some minor cosmetic improvements.
Pick-to: 6.3
Change-Id: Ie3b39600978ccfa4a009d3ff68567a348dc7b166
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
QThreadPool automatically deletes the runnable after it finishes running
the task. In case QThreadPool is nullptr, we should delete the runnable
manually. This amends 87b93c29be.
Pick-to: 6.3 6.2 5.15
Change-Id: Id7e4ed3d4d6de05990edf62e4099852983debc64
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
When an application is about to be closed and all the
destructors are called, if there isQtConcurrent::run on
the way, it crashes as the internal threadpool pointer
is nullptr.
Fixes: QTBUG-98901
Pick-to: 6.2 6.3
Change-Id: Idd84d1518fc6a225263e6666a0f1de2ccef79c82
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>
Using REQUIRED as a prefix instead of suffix works better with
OPTIONAL_COMPONENTS, and is also the order in the CMake manual.
Task-number: QTBUG-98867
Pick-to: 6.2
Change-Id: I1ab68408b95d8edf06272a3b9fceccd8d8e597fc
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
This should restrict changes that
introduce new warnings.
Change-Id: I7e4b5d9d5d84b7c336509c380bc7e6d86e360f4a
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
This patch removes most of the checks that are made using C++20
__cpp_* macros for features available in C++17 and earlier.
Library feature check macros (__cpp_lib_*) are unaffected.
Change-Id: I557b2bd0d4ff09b13837555e9880eb28e0355f64
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
The code for deducing the type of output sequence was assuming that the
input sequence is always a template class and was trying to use the
corresponding container type for the output sequence. Fixed the
deduction code, to assume that the output sequence has the same type as
the input sequence, when it's not a template class. Also added tests to
verify that all QtConcurrent functions support non-template input
sequences.
Fixes: QTBUG-30617
Pick-to: 6.2 6.1
Change-Id: I486fe99f3207cfff5dcceb3712cc7de863067edb
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
customFilters defined in .qdocconf are not supported anymore by Qt
Assistant since Qt 5.13. Therefore remove them from all .qdocconf files,
also to avoid cargo-culting them to new help modules.
Task-number: QTBUG-95987
Change-Id: I664391460637d2e859348da0338e1a4a3ee9f570
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Wrap the overloaded methods in qOverload(), to make the examples
compile.
Also remove the extra whitespaces when declaring nested templates.
Pick-to: 6.1 6.2
Change-Id: If438caa6d705d9036dae45278fb26e080918da89
Reviewed-by: Karsten Heimrich <karsten.heimrich@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
The QtConcurrent::RunFunctionTask class keeps a variable to store the
result of QtConcurrent::run when it becomes available, so that it can be
reported afterwards. This requires the result type to be
default-constructible. However there's no need in storing the result, it
can be reported immediately after it becomes available.
Pick-to: 6.1 6.2
Fixes: QTBUG-95214
Change-Id: I95f3dbff0ab41eaa81b104a8834b37d10a0d193a
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
After 6ebe3d0f08 users don't have to
specify the result type when using functors for as a reductor.
Task-number: QTBUG-88448
Change-Id: I065fed11c1a66833ba0aac3d18e7ff0545247be1
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
QStringList is a typedef for QList<QString>, so it doesn't need special
handling.
Change-Id: Ib371f9fa49d9d45da7956287dd0f5b6c0224f439
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
QtConcurrent reduce functions were requiring to explicitly pass the
the result type when passing functors as reductor. This was because of
inability to deduce the result type from the functors. The result type
of the QtConcurrent reduce functions should match with the type of the
fist argument of the operator() when a functor is passed. Reused the
ArgResolver type trait (already used for QFuture and QtConcurrent::run)
to find out the result type in that case.
Task-number: QTBUG-88448
Change-Id: Ief0eeee197df8cb9c30f3403d71978f36e4fb0f2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Replace the hardcoded cpp exports with a generated one where it's
applicable.
Task-number: QTBUG-90492
Change-Id: Idc160b594987b2c765e75bd669aae851b4366282
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
After 79fd1cb2c6 the methods for running
QtConcurrent algorithms in the blocking mode aren't used anymore. Since
ThreadEngineBase and ThreadEngineStarter classes aren't meant to be used
externally, it should be fine to remove startBlocking() methods now.
Removed the unused code and adjusted the tests accordingly.
Change-Id: Ifb13820ce207869d6f720bcb5be8d35bb355fe33
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
This seems to cause errors when compiling with gcc-11. Although this is
most likely a compiler bug, specifiying the template parameter type in
this case isn't necessary.
Fixes: QTBUG-91909
Fixes: QTBUG-90568
Pick-to: 6.0 6.1 5.15
Change-Id: Ib231257ccb2e16cc533f23ca5840d31e26a66d53
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Giuseppe D'Angelo
Dennis Oberst
Lucie Gérard
Topi Reinio
Ivan Solovev
Marc Mutz
Thiago Macieira
Fabian Kosmale
Jaishree Vyas
Hamish Moffatt
Mårten Nordheim
Friedemann Kleint
Luca Di Sera
Sona Kurazyan
Alexey Edelev
Kai Köhne
Tianlu Shao
Venugopal Shivashankar
Jonas Kvinge
Ievgenii Meshcheriakov