Replies: 6 comments 7 replies
-
|
See issue #7 Purego is not magic, it only allows dlsym/LoadLibrary of some C ABI library. But Qt is a C++ library, and the C++ ABI is compiler-defined, and function names are mangled. So, this requires either
|
Beta Was this translation helpful? Give feedback.
-
package main
import (
"github.com/ebitengine/purego"
"golang.org/x/sys/windows"
"runtime"
"syscall"
"unsafe"
)
func main() {
runtime.LockOSThread()
a := NewApp(0, []string{"", ""})
qWidget := NewQWidget()
b := NewQPushButton("button", qWidget)
b.OnPressed(func() {
})
b.Show()
qWidget.Show()
a.Exec()
}
var (
QApplication_newProc *syscall.Proc
QWidget_newProc *syscall.Proc
QWidget_showProc *syscall.Proc
QPushButton_newProc *syscall.Proc
QPushButton_showProc *syscall.Proc
QPushButton_connect_pressedProc *syscall.Proc
QApplication_execProc *syscall.Proc
miqt_exec_callbackProc *syscall.Proc
)
func init() {
check(windows.SetDllDirectory("."))
dll := syscall.MustLoadDLL("purego.dll")
QApplication_newProc = dll.MustFindProc("QApplication_new")
QWidget_newProc = dll.MustFindProc("QWidget_new")
QWidget_showProc = dll.MustFindProc("QWidget_show")
QPushButton_newProc = dll.MustFindProc("QPushButton_new")
QPushButton_showProc = dll.MustFindProc("QPushButton_show")
QPushButton_connect_pressedProc = dll.MustFindProc("QPushButton_connect_pressed")
QApplication_execProc = dll.MustFindProc("QApplication_exec")
miqt_exec_callbackProc = dll.MustFindProc("miqt_exec_callback")
}
type App struct {
handle uintptr //todo add more fields from C++ class members
}
func NewApp(argc int, argv []string) *App {
// 设置参数数量
argcPtr := uintptr(unsafe.Pointer(&argc))
// 为argv创建指针。如果没有参数，可以设置为nil
var argvPtr uintptr
if argv != nil && len(argv) > 0 {
argvPtr = uintptr(unsafe.Pointer(&argv[0])) // 获取argv的指针
} else {
argvPtr = 0 // 或者使用nil
}
// 调用外部函数
r1, _, err := QApplication_newProc.Call(argcPtr, argvPtr)
check(err)
return &App{
handle: r1,
}
}
func (a *App) Exec() {
QApplication_execProc.Call(a.handle)
}
func check(err error) {
if err != nil {
//panic(err)
}
}
type QWidget struct {
handle uintptr //todo add more fields from C++ class members
}
func NewQWidget() *QWidget {
r1, _, err := QWidget_newProc.Call()
check(err)
return &QWidget{
handle: r1,
}
}
func (w *QWidget) Show() {
QWidget_showProc.Call(w.handle)
}
type QPushButton struct {
handle uintptr //todo add more fields from C++ class members
}
func NewQPushButton(text string, parent *QWidget) *QPushButton {
title := [256]byte{}
copy(title[:], []byte(text))
r1, _, err := QPushButton_newProc.Call(
uintptr(unsafe.Pointer(&title)),
uintptr(unsafe.Pointer(parent.handle)),
)
check(err)
return &QPushButton{
handle: r1,
}
}
func (b *QPushButton) Show() {
QPushButton_showProc.Call(b.handle)
}
func (b *QPushButton) OnPressed(callback func()) {
return
purego.NewCallback(callback) //todo
QPushButton_connect_pressedProc.Call(b.handle)
}
|
Beta Was this translation helpful? Give feedback.
-
|
Nice! 🤩 I'm glad it worked! This is similar to the approach in kitech/qt.go: CGO is not needed, but an extra There does also exist a way to remove the purego.dll file. The If you want to add the By the way, I got some earlier emails from GitHub with your messages. Your english skill is excellent. @rcalixte was doing some similar work to make C and Zig binding versions of MIQT, he may also be interested. |
Beta Was this translation helpful? Give feedback.
-
|
That's what I've been regretting, not sure if there will be side effects like virtual functions of cpp's class performing destruction memory operations and all that, as well as assuming that qt introduces some of the cpp stl stuff, as you mentioned in the readme with all those maps, hashes, containers, etc., but you said that it should work on Android, so I'm going to give it a try anyway. I'm very new to cpp templates and hopefully the templates inside qt won't have side effects on cabi:panic, memory leaks, synchronization of events within a trip, etc., but hopefully it will work as always. Also, I'm not proficient in clang ast node traversal, so it would be great if you could easily add the dynamic library export prefixes for each platform to all gen_xxxx.h headers generated by miqt, so I can test them directly. You need to define the prefix syntax of the api export using macros according to each platform to make it compatible with all platforms. |
Beta Was this translation helpful? Give feedback.
-
|
Hi, still can't debug it after testing, also, not sure if it's possible to load so on android. do you have a static version of qt6.8 compiled by vs2022 on your side? |
Beta Was this translation helpful? Give feedback.
-
|
It's definitely possible to load The MIQT loader already uses something like
I don't have it. The person at https://build-qt.fsu0413.me/zh-cn/ is usually quite good about making such builds, but, he has only Qt 6.7 so far. In my opinion, MSYS2 is easier than VS. |
Beta Was this translation helpful? Give feedback.
-
I have tried to compile miqt demo under msys2 and it can be compiled successfully. As you mentioned, the first compilation is very time consuming, but when I copied the qt lib downloaded from the msys2 environment to a directory on Windows 11 to test it, neither using clion+cmake to test the cpp demo nor Goland to compile the miqt demo succeeded, suggesting that all the dependencies such as zlib dependencies don't seem to be embedded in the qt lib.into the qt lib. Finally I decided to try the purego approach, which eliminates the need for a pkg config, c and c++ compilers, and compiles very quickly, but when I tested for debugging with Goland, the plugin directory for the dynamic libraries for the platform was not initialized, and adding the directory to the path of the system environment variable didn't help. In the end I think the only way to debug is to link the static version of qt. By the way, the gcc compiled qt lib works fine in msys2, but when copying the compiled miqt demo binary to run in win11, it gives me an error about the missing libc++ dynamic library, and then I found the dll and copied it to the demo directory to no avail. But the qt compiled by vs2022 works fine. I feel that the static version of qt library+purego mode of vs2022 loads the cabi dynamic library exported by miqt, so that I can get the best development experience, and the debugging function should also work properly. |
Beta Was this translation helpful? Give feedback.
-
|
Yes, for the dynamic-linked MSYS2 build, many more dll files must be copied. You can use It's really a lot:
But, many of them are part of Windows, so copying them is not required. It's likely this is why your VS2022 build did not require any additional dll files: because the VS2022 runtime was installed at a systemwide level. Additionally to the imports declared in the EXE file and visible to ldd, Qt also requires to load its own plugin files (e.g. Qt C++ has the "windeployqt" tool that can find all such dll files automatically, but I think for Miqt it must be discovered manually. A statically linked Qt is much simpler. But because Qt is LGPL, static linking would require to make the application open-source. This can be unacceptable for some cases, so Miqt must support both ways. Although, statically linking the binding ("purego.lib / purego.a") and dynamically linking the remaining Qt libraries is acceptable. |
Beta Was this translation helpful? Give feedback.
-
|
Finally ready for debugging, need static qt library |
Beta Was this translation helpful? Give feedback.
-
|
i forked a rep for make static qt 6.9 use action The next step is to add static lib compilation for android, I don't know how to implement this inside action. The last step is to copy miqt's c abi bindings to generate code to implement dynamic libraries in pre-compiled c abi format for all platforms inside action. |
Beta Was this translation helpful? Give feedback.
-
|
Hello, I have a question for you. All the testing I've done so far has been under Windows, is there a way to use parse cmake or something else instead of pkg config to parse the compilation parameters, I'm guessing it should parse out the header file directory, compilation parameters and lib directory which are the configurations passed to clang to dump ast. I'll try copying the .pc file of the qt lib under Linux first. For now I need to get bindgen running before I can further change the header file export api operation. If you have time to spare, please check every one of my commits, thanks. |
Beta Was this translation helpful? Give feedback.
-
|
The pkg-config
The genbindings program still looks only at Clang's AST, so you need the Clang compiler for this part. If you have any difficulty running genbindings, a possible solution is to use the Docker container with all dependencies ready: https://github.com/mappu/miqt/blob/master/docker/genbindings.Dockerfile . This is the same container that runs in CI. It installs many extra things for all Qt 5 and Qt 6 libraries, but, the most important part is only I run genbindings from Linux, in this way. Then afterwards I make sure that the result still works OK on Windows, using only the cross-platform parts of Qt. If you start from Windows, some It's a holiday season, so I can check the repository only after a few weeks. I'm really interested to see your work, |
Beta Was this translation helpful? Give feedback.
-
thx, i will try. |
Beta Was this translation helpful? Give feedback.
Uh oh!
There was an error while loading. Please reload this page.
-
use https://github.com/ebitengine/purego
Beta Was this translation helpful? Give feedback.
All reactions