What am I doing wrong?
1. I write some code in Qt Creator, it works.
2. I save all, copy the folder with all the files in it to another location for safekeeping.
3. Then I write more code. This additional code doesn't work and I've gone too far to undo it.
4. So I close Qt, delete that folder, move the earlier one back to where it was originally, and load the older version.
But Qt still gives me the same errors that the newer code gave me, and won't run. It seems to remember this newer (bad) code even though it no longer appears anywhere in Qt - and the problem persists over computer reboot. I feel I'm missing something very obvious, but Mr Google can't help at all.
Try Build->Rebuild all. Your IDE is probably caching some of the previous results for performance reasons. I had the problem once using Qt Creator, and it solved it for me.
Delete the build folder. All that the build system knows about is the built files being newer than your now even older sources*. So a build won't succeed since plenty of intermediate files are wrong.
By the way, you really should be using version control, not moving folder around. I suggest git via smartgit, but that's just my personal preference. It's effortless.
* A build system could remember the absolute timestamps of the source used in the build and rebuild if they change, not only if the sources are newer than the results.
Related
I've got a problem for which I would very much like a solution please:
All I'm trying to do is use wxWidgets in Visual Studio 2012 (in C++), and make it accessible to my code project. That shouldn't be so hard, should it? But as usual, even though there are programming tutorials for it, wxWidgets is evidently one of those things that has no proper documentation just to simply get it running, or if it does then I sure can't find it.
I downloaded the installer for Windows and installed it. When it finished, it gave me a message that said:
wxWidgets was installed successfully!
Please note: before using wxWidgets in your application,
you must build the library using the same compiler you
use for building your program.
Please see docs/msw/install.md file in the installation
directory for the detailed instructions about how to build
wxWidgets and use it from your application.
It should be noted that I think I remember something on the website or somewhere saying that I can just include a header file into my project and forego the DLL altogether (which is what I'd prefer to do, if possible), though I may possibly be misremembering that or confusing it with something else.
Anyway, when I opened the docs/msw/install.md file, I found (amongst other things) these instructions:
--- From the IDE
Ready to use project files are provided for VC++ versions 8, 9,
10, 11, 12, 14, 15, 16 and 17 (also known as MSVS 2005, 2008, 2010, 2012,
2013, 2015, 2017, 2019 and 2022 respectively).
Simply open wx_vcN.sln (for N=8, 9, 10, 11, 12, 14, 15, 16 or 17) file,
select the appropriate configuration (Debug or Release, static or DLL)
and build the solution. Notice that when building a DLL configuration,
you may need to perform the build several times because the projects
are not always built in the correct order, and this may result in link
errors. Simply do the build again, up to 3 times, to fix this.
Of course, it doesn't even say WHERE the "wx_vcN.sln" files are, but I ran a file search and found them in C:\wxWidgets-3.1.6\build\msw and I opened the one called wx_vc11.sln, because that seems to be the one that corresponds to VS2012, right?
Anyway, it took a LONG time to load, because it had to keep scanning through thousands of files and so forth, but when it was finally finished, I did the "Rebuild All" command thrice in a row, like it says to do (which also took a while).
But I'm not sure where it even put the actual DLL file. It says that it's in C:\wxWidgets-3.1.6\build\msw....\lib\vc_lib\wxmsw31ud_xrc.lib, but where the hell is "...."? It doesn't even bother to specify the entire path! What kind of nonsense is that?! I just want the file so that I can put it into my project! Or better yet, just a .h file that takes care of everything would be great. Supposedly there's one to include called "wx/wx.h", which then includes everything else, I think, but I don't know if that one indirectly also requires a DLL.
I always have problems with DLLs, anyway, though I'll use one if I absolutely have to. You'd think it would be the easiest thing to import a DLL into a project, but for some reason, I've never been able to find any sort of tutorial that explains a specific, step-by-step way to do it which is guaranteed to work, so on the rare occasion that I actually need to use a DLL (99% of the time I can just rely on my own code and the .h files included with Visual Studio), I always end up muddling through it until it FINALLY works by sheer accident (if I'm lucky). Mostly, it just reports errors for one reason or another, that it's not properly included or compatible, or that the header files that I'm using which reference it keep showing the same errors, as though I hadn't even imported the DLL file at all! I've been programming for about 30 years, and I work on things like AI and compression and cryptographic algorithms. I don't say this to brag, but to point out that if someone as experienced as me has trouble getting a DLL to attach properly to a roject, then there's something severely wrong with the whole process, or the documentation for it! I HATE using DLLS, because it's always a HUGE chore, but I'll do it if there's absolutely no other way (though I'd appreciate step-by-step instructions, if you don't mind).
But enough about that. In any case, I have an example project in which wxWidgets is being used in conjunction with Vulkan, and though it has compilation errors (because Vulkan didn't properly install on my machine (when I try to run the sample programs it says they're missing DLLs - big surprise) and as it turns out, I don't think it's compatible with my video card, anyway (which might possibly be why it didn't install properly), so I think I'll have to resort to OpenGL instead - PLEASE tell me that's compatible with wxWidgets!), but even in that example project, it has errors where it's trying to include and use wxWidgets stuff (like "wx/wx.h"), even though that's supposed to be a complete and already working project! I can't find any DLL files or the header files in question anywhere in the project directories!
So anyway, there's got to be an easier way to get this all set up, just to the point that I can make a simple test program using wxWidgets, and compile it. I'd REALLY like to be able to get at least that much working sometime tomorrow morning, so I'd greatly appreciate any help you can give me! Thank you.
#ThisIsMe,
First of all you need to educate yourself on properly using C++.
When you acquire the C++ code it contains of 2 portion - header file and source code.
Header file is what you call a declaration you declare you classes there - class name, member variable and method.
In the source files You define what you declared and you put an actual code there.
Now with that in mind:
wxWidgets contains both header and source files. When you downloaded the installer and did the installation it just copied the "text file" (headers and sources) into the folder of you choice.
Now as you can imagine text files are not executable - you need to compile them into the binary files And that is exactly what you did. (I don't know why you did it 3 times though - I guess you got an errors after building 1st and 2nd time).
Now, you said you have a project that (either uses wxWidgets or you want to incorporate wxWidgets into - which one is it, BTW?). The answer to this question will help direct you to a proper solution.
Now, you said that you tried the Vulkan and it fails to run the demo. How did it fails? Did it produce an error? What was it? Did it even run?
Now wxWidgets does support OpenGL as can be seen by looking at the documentation and checking the different samples that comes with the library, but I'm just curious if what you are seeing from Vulkan is really an incompatibility with the Video Card.
So, we need you to answer the questions I put and so we can help you further. Just keep in mind - C++ is not for the beginner programmers and if you are struggling with understanding the difference between compilation, installation , headers and sources - it will be very hard for you.
Maybe you should start with something simpler - like wxPython and forget about C++ for now.
My current task is to set up a working environment for an application using (static) Qt and VTK, under Windows 10.
I successfully installed the Qt 5.11.1 static and now want to build VTK. Any version of VTK does, as long as it is compatible to Qt 5.11.1, and the Qt Modules (VTK_Group_Qt) have to be build. For my version, I decided on VTK 8.1.1, but as said, any version would do.
I used the CMake GUI to configure VTK, using MinGW Makefiles (I use a MinGW64), which worked. Then I wanted to proceed generating the Makefile, having turned on VTK_Group_Qt. The paths and version of Qt were already correctly recognized:
Qt5Core_DIR C:/build_environment/qt-everywhere-src-5.11.1/qtbase/lib/cmake/Qt5Core
Qt5Gui_DIR C:/build_environment/qt-everywhere-src-5.11.1/qtbase/lib/cmake/Qt5Gui
Qt5Widgets_DIR C:/build_environment/qt-everywhere-src-5.11.1/qtbase/lib/cmake/Qt5Widgets
Qt5_DIR C:/build_environment/qt-everywhere-src-5.11.1/qtbase/lib/cmake/Qt5
Made sure that all of those exist. After that, I hit Generate and got the following error:
The imported target "Qt5::Core" references the file
"C:/build_environment/qt-everywhere-src-5.11.1/qtbase/.../qt-everywhere-src-5.11.1/qtbase//mkspecs/win32-g++"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
* An install or uninstall procedure did not complete successfully.
* The installation package was faulty and contained
"C:/build_environment/qt-everywhere-src-5.11.1/qtbase/lib/cmake/Qt5Core/qt5CoreConfigExtras.cmake"
but not all the files it references
Now, we see that it goes one folder upwards from qtbase and then into the very folder it currently is in, which of course is not a legitimate path. That is, for some reason it tries to go up and then down again, but not with the right amount of folders.
I could try to move the contents of my Qt installation so that the path would be legitimate, but I'd consider that to be pretty much of a smell. Fiddling around in a folder structure that should be correct is not what I understand to be a good solution. I'd rather be willed to change one of the .cmake files of Qt, but that would also be more of a makeshift approach than a real solution as far as I am concerned.
One thing I tried so far was to look at all the CMake variables (checking Advanced in the CMake GUI) in order to see if everything appear to be in order, and especially to see if that faulty path to mkspecs is to be found somewhere there. Found nothing of particular interest.
Does anybody have an idea what went wrong? Tell me if additional information is required. In parallel, I will try to build other versions of VTK, but I'm not too confident that this will solve the issue.
I found a solution which I want to present here, but I consider it a makeshift approach rather than an actual solution, and I hope to see a better answer.
I went to qt-everywhere-src-5.11.1/qtbase/lib/cmake/Qt5Core/ and changed the file Qt5CoreConfigExtrasMkspecDir.cmake (after making a copy).
The original file contains a single line
set(_qt5_corelib_extra_includes "${_qt5Core_install_prefix}/.../qt-everywhere-src-5.11.1/qtbase//mkspecs/win32-g++")
which leads to the faulty path. I changed it to
set(_qt5_corelib_extra_includes "${_qt5Core_install_prefix}/mkspecs/win32-g++")
And it now works fine. Still, I don't feel good about having to change a file of Qt, since I consider the answer the question "Is this famous library at fault?" to be "Most likely I used it wrong."
A possible explanation would be that I used the wrong install prefix when configuring Qt, but shouldn't I be allowed to put any valid writeable path in there? Plus, the prefix is still in the cmake file and thus has some validity.
While this is an answer since it fixed the problem, I'd really like to read comments about what could have originally went wrong.
Recently I obtained a solution which has been created on another person's machine. I have been banging my head into the monitor in the past 2 days trying to fully migrate the solution to my machine. I have been manually changing the directory addresses of the solution and have not been able to compile the solution although I think I have corrected more than 100 paths as of now. Here's my first attempts to migrate the solution to my machine and resolve the issue of not being able to open any of the files.
Now I can open all the files in each project on my machine (after manually changing their paths). However, I am still getting the same errors and I'm not able to compile the project. Below is a picture of the errors I'm getting:
And here's the output log when trying to compile the project. So I wonder, can someone give me some advise on how I should go about doing the whole process automatically? In the output log I see there is a F:\Virtual ... path which indicates the solution been created on a virtual machine. However, I am not using a virtual machine and am not able to find the file file containing that path (F:...) so that I can change it to the correct one (I even do not know what the correct one should be since I am not using a VM).
If you are not able to help me through the description I gave or the output log file, you can download the whole solution from here and then give me some instructions on how I should go about compiling and using it. I really appreciate your help.
Chances are that someone went rogue on the project file, because normally all paths are defined in a way that is relative to the project or solution, making them portable.
In order to fix this, I see two options, either set up the project files from scratch or keep on hacking on them until they compile. Whichever path you take, keep in mind that VS supports placeholders like $(SolutionDir) you can refer to when setting up paths. If that doesn't work, please try to extract a minimal example.
Also, make sure you have a version control system set up, so you can retrace your steps. This should be standard in any software development, but considering the state of the project I wouldn't be surprised to find other, hairy places there.
I experienced this problem in VS2010 before, and solved it looking at this SO question. However, now that I upgraded my VS to SP1, it appeared again. I tried to solve it the same way, enabling C++ projects logging and using DebugView. But I can't get to see any output in DebugView, no matter what I do. I also tried raising the Build output verbosity (Tools->Options->Projects and Solutions->Build And Run), but couldn't find any clue.
As in the original problem, the projects reported as out of date are always unmanaged C++ projects. The solution has C#, VB.NET, C++/CLI and C++ projects. What I'm trying to run is a VB.NET exe which uses some C++ projects through C++/CLI wrappers.
Any hint on how to troubleshoot this?
UPDATE: Solved it with a clean checkout. However, it's a shame that there is no longer a way to troubleshoot this kind of errors...
Is it possible you were testing with the date in the future and saved a source file in the future? While clean/rebuild all should fix this, VS seems to go batty and stay there until I resave the file in the present.
Another last-ditch thing that sometimes solves these problems that works 'like a reboot' if you have just the source-code in version control: Check everything in, close VS and anything using files in your project, move all your project folders to a backup folder, and do a force-get latest version of each. Sometimes 'clean project' doesn't cut it.
If that doesn't work and you can't find a missing .h ... You can always fire up Process Monitor, set a filter, and dig in there.
Admittely all just stabs in the dark. Hope one hits the burgler! ;-)
After a compiler upgrade you should do a rebuild-all, if you haven't done that already.
For native C++ projects you can get "project out of date", but still nothing to build, if you have some include files in your project that doesn't actually exits. Like if you have deleted some unused .h files, but they are still part of the project.
we work under Linux/Eclipse/C++ using Eclipse's "native" C++ projects (.cproject). the system comprises from several C++ projects all kept under svn version control, using integrated subclipse plugin.
we want to have a script that would checkout, compile and package the system, without us needing to drive this process manually from eclipse, as we do now.
I see that there are generated makefile and support files (sources.mk, subdir.mk etc.), scattered around, which are not under version control (probably the subclipse plugin is "clever" enough to exclude them). I guess I can put them under svn and use in the script we need.
however, this feels shaky. have anybody tried it? Are there any issues to expect? Are there recommended ways to achieve what we need?
N.B. I don't believe that an idea of adopting another build system will be accepted nicely, unless it's SUPER-smooth. We are a small company of 4 developers running full-steam ahead, and any additional overhead or learning curve will not appreciated :)
thanks a lot in advance!
I would not recommend putting things that are generated in an external tool into version control. My favorite phrase for this tactic is "version the recipe, not the cake". Instead, you should use a third party tool like your script to manipulate Eclipse appropriately to generate these files from your sources, and then compile them. This avoids the risk of having one of these automatically generated files be out of sync with your root sources.
I'm not sure what your threshold for "super-smooth" is, but you might want to take a look at Maven2, which has a plugin for Eclipse projects to do just this.
I know that this is a big problem (I had exactly the same; in addition: maintaining a build-workspace in svn is a real pain!)
Problems I see:
You will get into problems as soon as somebody adds or changes project settings files but doesn't trigger a new build for all possible platforms! (makefiles aren't updated).
There is no overall make file so you can not easily use the build order of your projects that Eclipse had calculated
BTW: I wrote an Eclipse plugin that builds up a workspace from a given (textual) list of projects and then triggers the build. That's possible but also not an easy task.
Unfortunately I can't post the plugin somewhere because I wrote it for my former employer...