Null pointer while trying to read xml with boost - c++

I stumbled upon an interesting problem. I have managed to reduce the problem to the following code:
boost::property_tree::ptree properties;
boost::property_tree::read_xml("Additional Dependencies\\properties.xml", properties);
xml:
<Properties>
<PictureGenerator>
<miniatureHeight>4</miniatureHeight>
<miniatureWidth>4</miniatureWidth>
<imageHeight>8</imageHeight>
<imageWidth>8</imageWidth>
<ImagePath>Additional Dependencies\</ImagePath>
<Miniatures>
<Image>0.bmp</Image>
<Image>1.bmp</Image>
<!--<Image>2.bmp</Image>
<Image>3.bmp</Image>
<Image>4.bmp</Image>-->
</Miniatures>
</PictureGenerator>
</Properties>
When i build the project in Release mode, everything runs perfectly.
In Debug mode I get the following error:
Unhandled exception at 0x779e8e19 in my_project.exe: 0xC0000005: Access violation writing location 0x00000014.
I am using VS2010.
Upon further inspection the error is thrown in the read_xml_internal function while trying to create a vector from a basic_istream.
At first I thought that I gave the wrong path, but I works perfectly in Release mode.

I have found the source of the problem.
I have reproduced the same error with istream, and it turned out that I had a wrong property page set for Debug.
The problem was the property:
C/C++ -> Code Generation -> Runtime Libary as Multi-threaded
I have changed it to Multi-threaded Debug Dll and it works perfectly.

Related

Qt Creator and MSVC - Ignoring specific exception types on debugging?

I'm currently using Qt Creator 4.4.1 with Qt 5.9.2 and the MSVC 2015 32/64 Bit compilers to create a DLL on Windows 7.
In Qt Creator under
Projects -> Build & Run -> Desktop Qt 5.9.2 MSVC2015 xxbit -> Run -> Executable
I've specified the host application, that loads my DLL, so when I hit F5 this app gets executed and loads my DLL without a flaw.
However, on loading, the main app raises an exception which I have no hands-on, making Qt Creator showing up a message box with the following content:
The inferior stopped because it triggered an exception.
Stopped in thread 0 by: Exception at 0x60251637, code 0xc0000005: write access violation at: 0x1, flags=0x0 (first chance).
I now have to close the message box and hit F5 again to proceed.
Because I have to do this for every test run, again and again, it becomes really annoying. So, is there a simplest way to tell CDB from Qt Creator to ignore only that specific type of exception?
Look at the call stack, find the relevant code and see what it does. You should find a try ... catch ... around that line. See whether you can avoid the exception in some way, typically by introducing an if ... else ....
If you cannot avoid it, and you made sure it's really safe to ignore it, start CDB with command line argument -c "sxn c0000005" or the equivalent -c "sxn av", where AV is short for "access violation". You can use sx to see all exception settings.
I encountered the same problem, the problem may be caused by the variable is not initialized, for example:
QLable *lable;
If you forget to allocate memory for this variable, it will cause this error.
lable = new QLable(this);
I think you should check your variables.

SFML 2.2 Unhandled exception at 0x00007FFA622C21F9(sfml-system-2.dll)

I'm trying to build a game in sfml under windows 10.It shows successful at the time of building.whenever i debug the solution it shows the error message like:
Unhandled exception at 0x00007FFA622C21F9 (sfml-system-2.dll) in picpuz2.exe: 0xC0000005: Access violation reading location 0x0000000000000019.
Under call stack the program stopped at the code:
window.create(sf::VideoMode(300, 300, 32), "PICPUZ");
This is my code:
Please follow the tutorials closely. If you are doing a debug build, you should link with the dlls that end in -d for debug.
For example sfml-system-d-2.dll
Linking release and/or debug to the wrong configuration (release to debug or debug to release) will result in unpredictable crashes.

v8::Isolate::New null access violation

I'm using V8 32-bit Version 4.10.253 compiled with Visual Studio 2015.
I'm trying to run the example that Google has at:
Chrome V8 - Getting Started
But when I try to run it, I get:
Exception thrown at 0x00000000 in V8Test.exe: 0xC0000005: Access
violation executing location 0x00000000.
I get this when the following is executed:
Isolate* isolate = Isolate::New(create_params);
My project settings:
To get the project to compile in debug, I set the runtime library to:
Multi-threaded Debug /MTd.
I include the v8 include directory under additional include directories.
Lastly, I include the following libraries:
icuuc.lib icui18n.lib v8_libplatform.lib v8_external_snapshot.lib
v8_base_3.lib v8_base_2.lib v8_base_1.lib v8_base_0.lib v8_libbase.lib
winmm.lib
Anyone know what I'm doing wrong? Thanks in advance.
Ok, I feel stupid. I didn't finish reading the rest of the tutorial. You must copy all the .bin files where your executable is stored. Specifically:
natives_blob.bin
snapshot_blob.bin
V8 will crash at Isolate::New if you do not.

OpenCV Build ok, debug throws error, runs fine from .exe

Using Visual Studio 2010, OpenCV 2.2.2, Windows 7 64x
My code builds successfully then when it goes into debug I get the following error:
First-chance exception at 0x75f0c41f in MachineVisionHW0.exe: Microsoft C++ exception: cv::Exception at memory location 0x002dec90..
Unhandled exception at 0x75f0c41f in MachineVisionHW0.exe: Microsoft C++ exception: cv::Exception at memory location 0x002dec90..
Then I end debug, go to the file directory and run the built executable and it runs fine. Does anybody know how to fix this? It isn't keeping me from building my code, but it is incredibly inconvenient. I will include an example of the code that is doing this below.
int main(){
cv::Mat image1 = cv::imread("img1.JPG", CV_LOAD_IMAGE_GRAYSCALE);
cv::namedWindow("Sample1");
cv::imshow("Sample1", image1);
cv::waitKey(0);
return 1;
}
Do you get the unhandled exception before main?
If not, then your code is somehow doing something to raise the exception. Put a breakpoint on the first line, then hit F5, then once at the breakpoint, step through the code one line at a time to see which one causes the exception, F10 key to do this.
My gut feeling is that when running from the debugger, the cv::imread is failing since it is not finding the img1.jpg from the expected location, the current working directory is that of the solution file, not of the debug output build dir. You can do a quick test and copy the img1.jpg to the dir containing the sln file and see if that fixes the problem.

Is there a simpler Windows C++ Subversion API or an example .vcproj for minimal_client.c?

Following on the tails of my previous (answered) question...
SharpSvn makes calling the Subversion client API simple:
SvnClient client = new SvnClient();
client.Authentication.DefaultCredentials = new NetworkCredential(username, password);
client.CheckOut(new Uri("http://xxx.yyy.zzz.aaa/svn/repository"), workingCopyDir);
On the other hand, calling the client API from C/C++, as shown in minimal_client.c requires coding "closer to the metal", as it were, on Subversion.
Are there Windows libraries for C++ in Visual Studio 2003 that present a simpler interface than what minimal_client uses?
If there are not, is there a VS2003 C++ project (a .vcproj file) that demonstrates getting minimal_client to run? I'm able to compile minimal_client.c and link it using the following libraries:
libsvn_client-1.lib libsvn_delta-1.lib libsvn_diff-1.lib libsvn_fs-1.lib libsvn_fs_base-1.lib libsvn_fs_fs-1.lib libsvn_ra-1.lib libsvn_ra_local-1.lib libsvn_ra_svn-1.lib libsvn_repos-1.lib libsvn_subr-1.lib libsvn_wc-1.lib libapr-1.lib libaprutil-1.lib xml.lib libneon.lib
but when I run my application (in the debugger or start the release build without debugging), it runs for about 20 seconds without hitting the first line of main() and then throws this exception:
An unhandled exception of type
'System.TypeLoadException' occurred in
Unknown Module.
Additional information: Could not load
type apr_pool_t from assembly
minimal_client,
Version=1.0.3477.16033,
Culture=neutral, PublicKeyToken=null.
I've tried various combination of libsvn_.lib and svn_.lib to no avail.
Any thoughts on what I'm doing wrong?
EDIT: I started fresh with a "Win32 Console Project" (still in VS2003) and I am now able to debug the first few lines of my app. But now, on this line:
if (svn_cmdline_init ("minimal_client", stderr) != EXIT_SUCCESS)
I get a different exception (in the debugger or start the release build without debugging):
Unhandled exception at 0x7c91b21a in
Win32ConsoleProject_minimal_client.exe:
0xC0000005: Access violation writing
location 0x00000010.
EDIT: This thread explains that this error is a CRT mismatch between svn and stderr in my app. If I don't want to build Svn so they match (I don't want to), I can pass NULL instead of stderr (provided I'm willing to do without messages that would go to stderr) When I did this, my app ran all the way through correctly.
It seems that C++ wrappers are not overflowing the 'net. However, you may want to try SVNCPP, which can be yoinked from RapidSVN.
See http://rapidsvn.tigris.org/ for details (note: I've not tried it).
Can you upgrade to Visual C++ 2005 ? If so, you could just go using SharpSvn with C++/CLI.
Or even maybe stick to VC2003 and go SharpSvn with Managed C++ ? (not that I have any knowledge on the how od even the if)
edit: oh well, SharpSvn's homepage explicitely states that VC++ 2005 SP1 is required...