I've been searching arround StackOverflow but seems I can't find the exact explanation for my problem:
I am running a GUI Application compiled under Visual Studio 2012. As it is a GUI application, sometimes it's quite hard to Debug it normally, so I need to printout some values while executing. I've done a couple of printf but the problem is that, as it is a GUI application there is no Console available while debugging it. I need to debug and have a Console to display these output values from printf. I know under CodeBlocks it is possible to do so, however the project is quite big to have to migrate everything to gcc CodeBlocks.
Could anyone tell me how to display such console or how to workaround the problem and have a similar result?
Thank you very much
Windows applicaton can't be both GUI and console.
There is a workaround however:
If you applicatop is based on MFC use TRACE macro.
Otherwise make your own wrapper around OutputDebugString function.
Both will output to Visual Studio's 'Output' pane when you launch our program under debugger
An of course you can always output diagnostic messages to good old log file.
Related
I am making app to increase productivity in our company. It reads the whole .csv file and puts its contents to a table in .pdf format. I am using QT as GUI library and PoDoFo as .pdf library.
The thing is, after I let user select .csv file to get data from and path to save generated .pdf, the program crashes in two minutes or so. It varies from case to case. I was able to "track" the issue down to the QFileDialog.
It doesn't matter if I created it on the stack, or dynamically still the same thing happens. From the moment you press "Choose" in the GUI, which opens up file dialog, program will crash in something around a two minutes giving this in Visual Studio Community 2017
I was able to create minimalistic code, to reproduce the error. I am using Windows 7 Pro, Microsoft Visual Studio Community 2017, compiling 32-bit debug
.h,.cpp,.ui files: https://www.dropbox.com/sh/cf057p4lnumesol/AAD39zDJnrxGChXAuE7y27Kra?dl=0
Any help would be appreciated, I've spent 5 days of my free time trying to figure this out. Thanks
EDIT: I understand that the "Frame not in module" means that visual studio doesn't have debugging symbols for the part of code where crash occurred, since I did not built qt myself, that makes sense.
EDIT2: I am using QT Visual Studio Tools addon version 2.3.2
Qt version is 5.12.2
EDIT3: Crashes only occurs when compiling for 32-bit arch.
EDIT4: Crash is happening only if using native file dialog. If option QFileDialog::DontUseNativeDialog is set, then no crash occurrs.
Not sure if this is related, but I had an issue where if I gave a path to the FileDialog it would grind away for a few seconds because it was somehow interpreting it as a network path. To fix this I gave it a path that had a prefix of "file://". To accomplish this I did this:
QUrl().fromLocalFile(cell_info->progDir()).toString()
The original path came from cell_info->progDir(). Somehow that path was a regular windows specific path. Once I wrapped it in the from LocalFile call it produced what I needed for all platforms I was using it with.
Again, I have no idea if this is related to your issue, but it sounds fishy like it is grinding away in the background on something. If this is not related feel free to ignore.
Most IDE's I've seen (NetBeans, QtCreator, XCode, CodeBlocks, Eclipse) provide an out-of-the-box method to view standard output either in one of its embedded window or external console or in a log BUT Visual Studio.
I really don't want to allocate a separate console as it is suggested at THIS question. I'd also prefer not to redirect it to a file as it is suggested at THIS question (output file is not created with the suggested console command (2>output.txt)). Please don't give answers that modify the codebase like using OutputDebugString.
If displaying standard output inside VS this way is not possible, a working solution of the other two alternatives would still be welcomed, namely using external console (which I tried using without seeing the output in it) or a log file.
If it is only for debugging purposes, you might find Debug Breakpoints/Tracepoint actions helpful.
They enable to log custom strings with expressions (i.e. variables) to the visual studio console.
For a non-console windows application, by default (i.e. without changing your codebase, as you are requesting) all output to stdout is lost..
The dev environment in question consists of:
Windows 7
MinGW (g++)
CMake
Qt Creator
The problem is that Qt Creator, a lovely IDE as far as I can tell, does not display programs' command-line output. It seems to have its own proprietary debug pane, but it doesn't give me, for example, runtime errors. It just tells me that the program has failed and gives me the exit code. I'm using Creator only for its C++ capabilities, and not using Qt in any way, so the proprietary pane is useless to me.
So I ask this: Can something be done? Am I missing something really, stupidly obvious like a built-in command line? Or, if not, can I at least use some filthy and/or repulsive hack to get it to display the Windows command prompt upon running a program?
Last thing; I did do some research, and found a way to edit the Qt project file to display the prompt, but... I'm using CMake, not Qt projects. So that doesn't answer my question. If I can do something similar with CMakeLists.txt, that would be wonderful. But Google has failed me on that front, so I'm not holding out too much hope.
EDIT:
I'm specifically worried about runtime errors. cout and printf are rerouted to Qt Creator's window, so that's fine. I don't get runtime errors unless the debugger catches them, and the frequency of that is less than ideal.
Windows GUI programs don't have standard output.
In Windows there are two possible entry points in the standard runtime. The console one and the windows one. The console one will inherit console window from parent process or create a new one and connect the standard input/output/error streams to it, while the windows one will leave them unconnected unless they were explicitly redirected by the invoking process. A Qt application is (probably; you could have console Qt-Core application) a GUI application and Qt Creator (nor any other Windows IDE) does not redirect the output explicitly. Therefore the standard output is not open at all and the writes are being discarded.
However windows have separate logging facility for debugging purpose. This is what you see in the debug window. You can write to it using the native OutputDebugString API. I am sure you can also direct the Qt debug log there.
Note, that when it tells you the program has exited with status 0, it means the program ran, which in turn means it compiled successfully and thus there were no errors from g++. There may have been warnings, in which case you should see them in the appropriate other window. Compiler and program output are different things; the IDE does read the compiler output.
I feel like this is a stupid question, but I can't seem to figure out the answer. I've currently got a C++ application that's loading & utilizing a DLL (I compiled both the application & the DLL with VS 2010). I'm positive it's using the DLL, because a) if I rename the DLL, I get a not found exception, and b) it's displaying output that only comes from (and I can change it to see the output change) inside the DLL.
My problem is that in Visual Studio's Modules window while debugging, the DLL does not appear to be loaded. Because of this, obviously its got no symbols and I can't set breakpoints... But this doesn't make any sense to me as it's clearly using the DLL.
I've seen several other similar questions, and the answer has generally been too look at whether the code is native, managed, or mixed, and set the "Attach to Process" field accordingly. I've tried all the options there, and made sure my Debugger Type is set to "Mixed" (though I've tried it with Native & Managed as well, just to verify none of these solve the issue).
Does anyone have any suggestions?
Thanks in advance!
This happened to me and I found the project->properties->Debug page and clicked the box to Enable native code debugging. I was doing a C# project accessing a C++ / native dll
budward
I have some ideas:
check output windows it the DLL symbols are missing.
Make sure dllname.pdb file exist beside the DLL
make sure visual studio solution has two projects (EXE,DLL) projects
switch to DEBUG mode instead of RELEASE mode.
run process explorer (download it from MS) and check the path of the DLL that is bonded to the EXE in runtime.
Finally the ultimate solution:
Open Process Explorer and search for your DLL name.
Find which EXE is using it.
Goto VS and attach your debugger to that EXE.
I hope any of those fix your issue
I'm a hobbyist developer and have a background with Java (IDE of choice was Eclipse). I'm using Visual Studio Express 2010 and wanting to learn C++.
Few questions:
I create a "HelloWorld" in C++ and compiles/runs in VS/Windows. When I try to compile it under Linux/GCC, it obviously throws tons of errors. Default windows console project includes windows specific files; but if just create an "Empty Project" it throws tons of linker/build errors. What's the best practices here to keep my code portable?
Why is it creating 47 files for 8 lines of code?
How do you format code? You can do Edit->Format Selection, but the hotkeys don't work?
How do I output to VS's 'Output' Window? ( like eclipse does when you run a console java app )
It keeps reverting my "Project Location" to my "home directory" every time I restart. How do you change it? Is it a bug? Because it's Express edition?
Is there a way to keep it from switching to Debug view when it runs?
I create a "HelloWorld" in C++ and
compiles/runs in VS/Windows. When I
try to compile it under Linux/GCC, it
obviously throws tons of errors.
Default windows console project
includes windows specific files; but
if just create an "Empty Project" it
throws tons of linker/build errors.
What's the best practices here to keep
my code portable?
For portable code, avoid VS wizards entirely. Use Make/NMake if you're starting with rocks and sticks, or the portable build system of your preference (Ant, CMake, etc.) Some of these will spit out a VS solution/project file for you to use.
Why is it creating 47 files for 8
lines of code?
Wizards are magical like that.
How do you format code? You can do
Edit->Format Selection, but the
hotkeys don't work?
Ctrl-K Ctrl-F (under Edit, Advanced)
How do I output to VS's 'Output'
Window? ( like eclipse does when you
run a console java app )
Lookup OutputDebugString() for the debug window. Output window should get all cout/cerr output.
It keeps reverting my "Project
Location" to my "home directory" every
time I restart. How do you change it?
Is it a bug? Because it's Express
edition?
Probably hidden in options somewhere - don't know that one, sorry.
Is there a way to keep it from
switching to Debug view when it runs?
Launch using Ctrl+F5 to run without the debugger attached.
Have fun!
I create a "HelloWorld" in C++ and compiles/runs in VS/Windows. When I try to compile it under Linux/GCC, it obviously throws tons of errors. Default windows console project includes windows specific files; but if just create an "Empty Project" it throws tons of linker/build errors. What's the best practices here to keep my code portable?
It's fairly difficult to keep your code truly portable if you're writing Windows applications. Standard C++ will obviously work on either platform, but Linux can't run Windows applications, and vice versa. Remember that console applications are also considered Windows applications. They're not any more "pure" just because they are text-based, rather than graphical. Windows applications have their own entry point, different from the standard main function found in ANSI C++ (technically, main is still there, but it's hidden and called internally by the Windows libraries).
The best thing to do is not to link to any of the Windows headers. Unfortunately, you won't be very satisfied with the results. About all that you'll be able to generate is library code. You can't get a UI on the screen unless you use the Windows functions to do it.
An "Empty Project" is just what it says—empty. I assume the build errors are because you're trying to call functions that aren't defined anywhere. You'll find that you need to include windows.h to get off the ground, which instantly makes your code non-portable.
Why is it creating 47 files for 8 lines of code?
This is obviously an exaggeration; none of the wizards produce anywhere near that many code files. Especially not the "Empty Project", which doesn't create any at all.
A Win32 console application includes the following 5 files:
stdafx.h and stdafx.cpp — these files are used to enable "precompiled headers", meaning that Visual Studio will compile all of your headers once, and only recompile them when they change, rather than recompiling them each time you build the project. This used to provide enormous speed boosts, and still does on large projects. You probably don't need or care about this for small projects, but it's not a bad idea to get familiar with their usage if you're going to be developing in Visual Studio.
A targetver.h file, whose only purpose is to specify the earliest version of Windows that you want your application to run on. This is necessary because later versions of Windows add additional functionality that wasn't available in previous versions. Your app won't run if you link to functions or libraries that don't exist. Set this up once and then forget about it.
A <projectname>.cpp file, which is the implementation code for your application. This is pretty standard stuff—it includes the _tmain function, which is the entry point for a console app.
A ReadMe.txt file, which you can immediately delete. It contains some introductory information and describes the files that have been added to your project. (Yes, reading this yourself could have answered this question.)
A Win32 application would have a few more files, but most of the same ones as well. In particular, you'll see a resource file (with the extension .rc) that contains the icons, dialogs, bitmaps, cursors, etc. used in your program.
If you don't like this structure, you can either forgo the use of a wizard, or modify it yourself. There's nothing set in stone about it.
How do you format code? You can do Edit->Format Selection, but the hotkeys don't work?
Formatting code works fine. I'm not sure why people are telling you that Visual Studio doesn't support this, or that you'll need a third-party plug-in. There's no "Format Document" command as there is in C#, but the "Format Selection" command works just fine. The only difference is, you have to select something in order for it to be enabled.
The default keyboard extension for that command is CtrlK, Ctrl+F. It also works fine, right out of the box. My typical workflow is to hit Ctrl+A first to select all.
How do I output to VS's 'Output' Window? ( like eclipse does when you run a console java app )
I don't know what Eclipse does, nor do I know anything about Java. What do you want this to do? When and what things do you want to get written to the "Output" window? A console application will run in a console window, not in the "Output" window. That's not what it's for.
It's intended for debugging purposes. The OutputDebugString function is one way of utilizing it. The output of the standard cerr keyword should be automatically redirected to the "Output" window.
It keeps reverting my "Project Location" to my "home directory" every time I restart. How do you change it? Is it a bug? Because it's Express edition?
This isn't a bug, it's a feature. Visual Studio is designed for working with projects and solutions, not one-off code files. So by default, it prompts you to specify a project folder, a location to store your files. And what better place for the default location than your home folder?
If you don't like that location, you can change it. Under the "Tools" menu, select "Options". Expand the "Projects and Solutions" category, and click the "General" item. Then, change the path of the "Projects location" (the top textbox). Couldn't get much simpler than that.
Is there a way to keep it from switching to Debug view when it runs?
I frankly don't understand how this question makes any sense at all. When you run an application with the debugger attached, Visual Studio switches to a different window layout specifically optimized for debugging. I just answered a similar question. The upshot is that there's no way of telling Visual Studio to use the same window layout for both design and debug view, but I also can't imagine why you'd want to, either. Different things are useful, depending on what you're currently doing.
The two window layouts are customizable, and your changes are remembered. I've customized mine heavily from the defaults; it's very likely that your tastes vary as well. There are lots of great features, like the "Locals" window, which shows a listing of all the values of the local variables in scope at the point where you break into your program's execution.
Also remember that the default "Debug" and "Release" build configurations have nothing to do with whether or not Visual Studio automatically attaches the debugger to your application's process. If you want to start your app without the debugger attached, select "Start without Debugging" from the Debug menu, or press Ctrl+F5. There are lots of side effects to this though, and it's probably not what you wanted. Without the debugger attached, you lose most of what Visual Studio provides to you as an IDE. You might as well just run the app from Windows Explorer without even launching VS.
Finally, if you prefer Eclipse (or at least are already accustomed to its nuances and prefer not to learn Visual Studio's), you can still use it for C++ development. Download it here.
If you're just wanting to learn C++ and you don't necessarily care about the platform, I would probably avoid using Visual Studio to start with. Visual Studio provides some functionality for managing projects and builds, but honestly, I think you're better off learning how to manage code files and use the compiler on the command line first, then working up from there.
If you're on Windows, I'd recommend installing Cygwin and getting the GNU compiler tools through the Cygwin setup utility (gcc or g++).
This is a bit of an opinionated answer, but my experience with C++ on Windows leads me to believe that you'd be better served trying to learn C++ from more of a unix-like angle. Windows C++ adds a whole layer of crap that will just confuse you when you're getting started.