qt5base-lts/tests
Alexandru Croitor 47b879aa0b CMake: Place resources into static libraries, not object libraries
Take 2.
Re-land previously reverted commit, due to not handling resource names
that are not valid c++ identifiers. Now we sanitize the resource names
just like rcc does by replacing non-alphanumeric characters with
underscores.

Original commit message.

During the Qt 5 -> Qt 6 and qmake -> CMake porting time frame, it was
decided to keep resources in an object file (object library), rather
than putting them directly into a static library when doing a static
Qt build, so that the build system can take care of linking the
object file directly into the executable and thus not forcing
project developers to manually initialize resources with
the Q_INIT_RESOURCE() macro in project code.

This worked for most qmake and cmake projects, but it created
difficulties for other build systems, in the sense that these projects
would have to manually link to the resource object files, otherwise
they would get link time errors about undefined resource symbols,
assuming they kept the Q_INIT_RESOURCE() calls.
If the project code didn't contain Q_INIT_RESOURCE calls, the
situation would be even worse, the linker would not error out,
and the missing resources would only be discovered at runtime.

It's also an issue in CMake projects that try to link to the
library files directly instead of using the library target names,
which means the object files would not be automatically linked in.
Many projects try to do that because we don't yet offer a convenient
way to install libraries and reuse them in other projects (the SDK
case), so projects end up shipping only the libraries, without the
resource object files.

We can improve the situation by moving the resources back into their
associated static libraries, and only keeping a static initializer as
a separate object file / object library, which references the actual
resource initializer symbol, to ensure it does not get discarded
during linking.

This way, projects that link using targets get no behavior difference,
whereas projects linking to static libraries directly can still
successfully build as long as their sources have all the necessary
Q_INIT_RESOURCE calls.

To ensure the resource symbols do not get discarded, we use a few new
private macros. We declare the resource init symbols we want to keep as
extern symbols and then assign the symbol addresses to volatile
variables.
This prevents discarding the symbols with the compilers / linkers we
care about.

It comes at the cost of an additional static initializer per resource,
but we would get the same + a bigger performance hit if we just used
Q_INIT_RESOURCE twice (once in the object lib and once in project
code), which internally needs to traverse a linked list of all
resources to check if a resource was initialized or not.

For GHS / Integrity, we also need to use a GHS-specific pragma to keep
the symbols, which we currently use in qtdeclarative to ensure qml
plugin symbols are not discarded.

The same macros will be used in a qtdeclarative change to prevent
discarding of resources when linking to static qml plugins.

A cmake-based test case is added to verify that linking to static
libraries directly, without linking to the resource initializer
object libraries, works fine as long as the project code calls
Q_INIT_RESOURCE for the relevant resource.

This reverts commit bc88bb34ca.

Fixes: QTBUG-91448
Task-number: QTBUG-110243
Change-Id: Idce69db0cf79d3e32916750bfa61774ced977a7e
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
2023-08-14 14:05:32 +02:00
..
auto CMake: Place resources into static libraries, not object libraries 2023-08-14 14:05:32 +02:00
baseline Baseline tests: wait longer before taking a screen snapshot 2023-04-20 15:17:25 +02:00
benchmarks QByteArray: use new assign() in operator=(const char *) 2023-08-11 14:11:44 +02:00
global tst_bic: Add linux-gcc-ia32 bic data for QtXml 2013-01-16 08:25:28 +01:00
libfuzzer Change the license of all CMakeLists.txt and *.cmake files to BSD 2022-08-23 23:58:42 +02:00
manual embeddedintoforeignindow test: port itemwindow.h away from Q_FOREACH 2023-08-09 23:57:22 +02:00
shared Add embeddedwindows manual test 2023-08-07 22:59:19 +02:00
testserver Use SPDX license identifiers 2022-05-16 16:37:38 +02:00
CMakeLists.txt Rid of 'special case' markers 2023-04-13 18:30:58 +02:00
README Doc: Fix references to Qt Test 2013-01-30 01:35:06 +01:00

This directory contains autotests and benchmarks based on Qt Test. In order
to run the autotests reliably, you need to configure a desktop to match the
test environment that these tests are written for.

Linux X11:

   * The user must be logged in to an active desktop; you can't run the
     autotests without a valid DISPLAY that allows X11 connections.

   * The tests are run against a KDE3 or KDE4 desktop.

   * Window manager uses "click to focus", and not "focus follows mouse". Many
     tests move the mouse cursor around and expect this to not affect focus
     and activation.

   * Disable "click to activate", i.e., when a window is opened, the window
     manager should automatically activate it (give it input focus) and not
     wait for the user to click the window.