I want to test out QT WebAssembly for my scientific program.
Therefore, I installed emscripten.
$em++ --version
returns
emcc (Emscripten gcc/clang-like replacement) 1.38.30 (commit a5082b232617c762cb65832429f896c838df2483)...
Then I installed Qt using the Qt WebInstaller.
In my installation directory I have a wasm_32 folder which contains bin and qmake:
$ ~/Qt_web/5.13.2/wasm_32/bin/qmake --version
return
QMake version 3.1
Using Qt version 5.13.2 in /home/myName/Qt_web/5.13.2/wasm_32/lib
However, when I start Qt creator, click on Projects I see a Kit called: Qt 5.13.2 WebAssembly but I cannot select it (it is grayed out).
When I click on manage Kits I saw that there is no C and C++ compiler selected for Qt 5.13.2.WebAssembly.
I also get an warning when I change to Qt Versions. The warning says:
ABI detection failed: Make sure to use a matching compiler when building. No qmlscene installed.
This is a list of all compilers which are selectable:
Question:
I do not really understand what emscripten has to do with all that. Is emscripten a compiler? If yes should it have been auto-selected by the Qt 5.13.2 WebAssembly kit?
How does a proper Qt WebAssembly kit look like?
If I select gcc as my compiler I get an error saying:
/home/myName/Qt_web/5.13.2/wasm_32/plugins/platforms/libqwasm.a:-1: error: error adding symbols: File format not recognized
EDIT:
When I open the qt maintenance tool and look at the installed packages I get the following:
EDIT2:
After changing to Qt Creator 4.11.0-beta2 (4.10.83) I was able to follow parts of this description. I was able to select the Plugin, but I still can not change the Device type.
Maybe it has to do with this error that I get now:
EDIT3:
seems as if my emscripten compiler has some problems.
Is the compiler located in:
emscripten/emsdk/clang/e1.38.30_64bit/clang++
emscripten/emsdk/clang/e1.38.30_64bit/clang
One thing I noticed is that If I use add in QtCreator >> Kits >> Compilers and I select Add >> WebAssembly >> C It generates a new entry in Manual >> C++ >> Emscripten Compiler and not in Manual >> C >> Emscripten Compiler. Is this a problem?
EDIT
This is how my Compilers page looks like:
You need to copy the .emscripten file from emsdk directory to your home (/home/myUsername).
You need to fix the paths in the file manually (See example below).
Notice that .emscripten file , at least in the version (1.39.8) i am using, is a python script (maybe a bug?)
example file before edit:
import os
emsdk_path = os.path.dirname(os.environ.get('EM_CONFIG')).replace('\\', '/')
NODE_JS = emsdk_path + '/node/12.18.1_64bit/bin/node'
LLVM_ROOT = emsdk_path + '/upstream/bin'
BINARYEN_ROOT = emsdk_path + '/upstream'
EMSCRIPTEN_ROOT = emsdk_path + '/upstream/emscripten'
TEMP_DIR = emsdk_path + '/tmp'
COMPILER_ENGINE = NODE_JS
JS_ENGINES = [NODE_JS]
after edit:
import os
emsdk_path = os.path.dirname(os.environ.get('EM_CONFIG')).replace('\\', '/')
NODE_JS = '/home/myUsername/node/12.18.1_64bit/bin/node'
LLVM_ROOT = '/home/myUsername/upstream/bin'
BINARYEN_ROOT = '/home/myUsername/upstream'
EMSCRIPTEN_ROOT = '/home/myUsername/upstream/emscripten'
TEMP_DIR = '/home/myUsername/tmp'
COMPILER_ENGINE = NODE_JS
JS_ENGINES = [NODE_JS]
When above steps are completed qt creator was able to detect the Emscripten Compiler with no errors.
Have you try in the kits tab to set your compiler with this values?
Compiler:
C compiler x86 64 e1.38.27_bit
C++ compiler x86 64 e1.38.27_bit
Qt version:
path to you qmake built with webassembly, for example webassembly binaries or your custom binaries.
Qt mkspec:
wasm-emscripten
Hope this information helps, if you face any other problem let me know.
Related
I am developing a QT GUI for my application using QT Creator (4.11.0).
Recently, our IT updated my OS to Ubuntu 20.04 (from 18.04) - maybe the error is related to that.
I have not touched to project in some month but yesterday wanted to continue developing it.
However, within the IDE there are now thousands of errors highlighted at almost every line of my code. (with highlighted I mean that there is this red background and a red dot beside the line number)
On the very top, it says:
Warning: The code model could not parse an included file, which might lead to incorrect code completion and highlighting, for example.
cstddef:50:10: fatal error: 'stddef.h' file not found
...
The errors that are listed in the IDE are very wired like:
type `QMainWindow`is not a direct or virtual base of `MainWindow` (my class is called `MainWindow`)
I'm pretty sure it is not related to my code:
the code compiles and works fine - it is really just the IDE that is highlighting errors at every line of my code.
I have the same code on a Windows Computer and there no errors are listed in the IDE.
even if I start a brand new QT Widget project the errors appear within the template code provided by the QT Creator.
Since the GCC version changed with the update of the OS, I thought maybe I have to define a new KIT but this also did not help.
Is there anything I can do to fix the issue?
Do I have to reinstall the QT Creator?
I know, pictures are not very well-liked but here I think it might help to understand what I mean with "IDE is highlighting errors":
1. First
~/.profile :
CPATH="/usr/include/clang/10/include:$CPATH"
C_INCLUDE_PATH="/usr/include/clang/10/include:$C_INCLUDE_PATH"
CPLUS_INCLUDE_PATH="/usr/include/clang/10/include:$CPLUS_INCLUDE_PATH"
export CPATH
export C_INCLUDE_PATH
export CPLUS_INCLUDE_PATH
maybe /usr/include/clang/10/include see in you file system.
2. Second
Logout / login.
3. Third
Specifying Build Settings (Projects -> Build -> in every config build) in Build Environment section: [unset] CPATH, C_INCLUDE_PATH and CPLUS_INCLUDE_PATH
or [edit] replace this variable with the necessary values
I fixed this issue by sudo apt install clang-8.
Source: https://bugs.launchpad.net/ubuntu/+source/qtcreator/+bug/1890434
So here I am, compiling my CMake-based C++ Projects in my terminal like there's not tomorrow with gcc-7.2.0 on Xubuntu 16.04 (via ppa)
Everything works fine and the new features add considerable value to my codebase.
However, trying to compile the very same project in qtcreator with the same compiler yields me errors like the following
: error: expected ‘)’ before ‘;’ token
if (auto event = events_.find(eventName); event == end(events_)) {
^
: error: ‘else’ without a previous ‘if’
} else {
^
if trying to compile initializer-ifs. I tried to manually pick gcc-7 in the build&run section in qtCreators options but without success. So my question is this:
What do I have to adjust in the IDE to make it conform to this latest standard?
If you're compiling Cmake projects in Qt creator, just be sure there is a line like this in your CMakeLists.txt:
set(CMAKE_CXX_STANDARD 17)
To use gcc-7.2.0, be sure it is listed in the Compilers tab of the Build & Run section in Tools/Option. Then, in Kits tab, select the kit you configured your project with, and select gcc-7.2.0 as the the kit's compiler.
If you're using qmake, instead, add this line to your pro file:
QMAKE_CXXFLAGS += -std=c++17
Currently I can build my program using boost build in different platforms by setting the toolset and parameters in the command line. For example :
Linux
b2
MacOS
b2 toolset=clang cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++"
Is there a way to create a rule in the Jamroot file to decide which compiler to use based on the operating system? I am looking for something along these lines:
import os ;
if [ os.on-macos ] {
using clang : <cxxflags>"-stdlib=libc++" <linkflags>"-stdlib=libc++c ;"
}
in linux it automatically decides to use gcc but in the mac if I don't specify the clang toolset it will try (without success) to compile it with gcc.
Just for reference, here is my current jamroot (any suggestions also appreciated):
# Project requirements (note, if running on a Mac you have to build foghorn with clang with libc++)
project myproject
: requirements <cxxflags>-std=c++11 <linkflags>-std=c++11 ;
# Build binaries in src
lib boost_program_options ;
exe app
: src/main.cpp src/utils src/tools boost_program_options
;
How abou using a Jamroot? I have the following in mine. It selects between two GCC versions on Linux, depending on what's in an environmen variable, and chooses vacpp on AIX.
if [ os.name ] = LINUX
{
switch [ modules.peek : ODSHOME ]
{
case *gcc-4* : using gcc : 4.4 : g++-4.4 ;
case *gcc-3.3* : using gcc : 3.3 : g++-3.3 ;
case * : error Only gcc v4 and gcc v3.3 supported. ;
}
}
else if [ os.name ] = AIX
{
using vacpp ;
}
else
{
error Only Linux and AIX supported at present. ;
}
After a long time I have found out that there is really no way (apart from very hacky) to do this. The goal of Boost.Build is to let the toolset option for the user to define.
The user has several ways to specify the toolset:
in the command line with --toolset=gcc for example
in the user configuration by setting it in the user-config.jam for all projects compiled by the user
in the site configuration by setting it in the site-config.jam for all users
the user-config.jam can be in the user's $HOME or in the boost build path.
the site-config.jam should be in the /etc directory, but could also be in the two locations above.
In summary, setup your site-config or user-config for a pleasant experience, and write a nice README file for users trying to compile your program.
Hope this helps someone else.
I am using Qt 4.8.1, MinGW compiler and Qt Creator, all on windows 7. I want to add an encryption/ decryption library to my project. After searching the web for couple days I found QCA. Fortunately I found a pre-built version using the same C++ compiler I am using, and a pre-built version of the needed plugins.
I followed the instructions to add the QCA library to my project. I used a code like this to encrypt using AES:
QCA::Initializer init = QCA::Initializer();
//Here where the execution stops
QCA::SymmetricKey key = QCA::SymmetricKey(16);
QCA::InitializationVector iv = QCA::InitializationVector(16);
QCA::Cipher cipher = QCA::Cipher(QString("aes128"), QCA::Cipher::CBC,
QCA::Cipher::DefaultPadding, QCA::Encode,
key, iv);
if (!QCA::isSupported("aes128-cbc-pkcs7"))
{
qDebug() << "AES128 is not supported";
return;
}
The code compiles just fine but when I run the application stops with unknown reason.
I really got tired from this bug, if anybody can help it will be very very very appreciated.
For future programmers that might get stuck on this
QCA loads the plugins at runtime, so even if it compiles fine, if the plugin is not in a searchable folder, it won't load.
You can check if that's the problem by calling qDebug() << QCA::supportedFeatures();. If the plugins are not being loaded, you'll get something like:
("random", "md5", "sha1", "keystorelist")
You should be able to see the folders QCA is looking up by calling:
qDebug("%s", QCA::pluginDiagnosticText().toUtf8().constData());
Apparently, plugins must be placed in a subdirectory called crypto in the libs root directory.
You can check for all the paths where Qt looks for libraries using:
qDebug() << QCoreApplication::instance()->libraryPaths();
This documentation might have some useful information: http://doc.qt.io/qt-4.8/qpluginloader.html
I'm trying to use ChangeWindowAttributes() function in Qt Creator project on Mac OS X.
But I can't build the project.
What I've tried:
#include <MacWindows.h>
Result (compiler): File not found
#include <Carbon/Carbon.h>
// Or the same:
#include </Developer/Headers/FlatCarbon/MacWindows.h>
Result (compiler): ChangeWindowAttributes was not declared in this scope
#include <Carbon/Carbon.h>
extern OSStatus ChangeWindowAttributes (
WindowRef window,
WindowAttributes setTheseAttributes,
WindowAttributes clearTheseAttributes
);
// And in *.pro file:
LIBS += -framework Carbon
Result (linker): Undefined Symbols ChangeWindowAttributes( ...
Where am I wrong?
According Google it seems that everybody already knows how to include it, so there are no guides anywhere. Maybe someone here also has a link to the guide or something?
By default, QT Creator build your project in your Mac's CPU architecture. The libraries themselves come in x86 and x86_64 universal binaries. This is if you are using the prebuild SDK from Nokia.
If you are running 64-bit capable OS/Mac combination, like 10.6 on a new Intel Mac, it will build it in x86_64. Carbon calls are still available to your code but only those marked as 64-bit compatible one. Open MacWindows.h and find ChangeWindowAttributes. You will see in the comment:
* Availability:
* Mac OS X: in version 10.0 and later in Carbon.framework [32-bit only]
* CarbonLib: in CarbonLib 1.0 and later
* Non-Carbon CFM: not available
If you have to call this (and other 32-bit only) function, you'll have to force Creator to build it in 32-bit (x86). Add these lines to your .pro file:
CONFIG -= x86_64
CONFIG += x86
Clean all and rebuild.