I'm using visual studio code with the c++ extension and gnu debugger on ubuntu 14.04.
I'm setting a watch expression in my program, which works as expected, but I'd like to trigger the debugger to break when that condition becomes true. How can you do that with visual studio code? The documentation is pretty thin on this subject.
Why don't you add a block that you can break at?
For example, make a condition:
while(true)
{
//stuff is happening
if(condition_happened)
{
std::cout<<"things happened"<<std::endl; //break here
}
}
Related
Hi I have a big problem: We created a program in C++/Qt 4.8.4 /Qt Creator 2.8.1 years ago that while executing runs another executable (written and compiled in FORTRAN). Everything worked well.
We recompiled our Fortran-Code with the new version of Visual studio and now suddenly it doesn`t work any more. I looked into my C++-Code and found the position where the program crashes:
std::string Executable = ApplicationName.toStdString();
bool RunOK= system((Executable+" > "+"X.out2").c_str());
QString ExeName = (Executable+" > "+"X.out2").c_str();
QString tf = QString::number(qweee);
if(system((Executable+" > "+"X.out2").c_str()))
{
msg.showMessage("msg.showMessage("An XXX error occured during calculation......((Executable+ > +X.out2).c_str(): "+ExeName +"......(system((Executable+ > +X.out2).c_str()): "+ QString::number(RunOK));
if(QFile(OutputFiles[0]).exists())
QFile(OutputFiles[0]).remove();
}
Somehow system((Executable+" > "+"X.out2").c_str()) gets to be true which didn`t happen before.
This seems to happen either in the c_str-command or in the system()-command.
We had some missing dll-issues before. Is this another dll-problem and if so which?
Can anybody help us on this?
Thank you
The return value of system is an integer, not a boolean. Its value is only defined for one very special case, system(nullptr). That's not the case here. So whether you get a zero or non-zero result depends on your particular C++ implementation, which has indeed changed. ("New visual studio version"). You can't rely on non-zero means error
c_str() is not a suspect at all.
When using CLion I have found the output sometimes cuts off.
For example when running the code:
main.cpp
#include <stdio.h>
int main() {
int i;
for (i = 0; i < 1000; i++) {
printf("%d\n", i);
}
fflush(stdout); // Shouldn't be needed as each line ends with "\n"
return 0;
}
Expected Output
The expected output is obviously the numbers 0-999 on each on a new line
Actual Output
After executing the code multiple times within CLion, the output often changes:
Sometimes it executes perfectly and shows all the numbers 0-999
Sometimes it cuts off at different points (e.g. 0-840)
Sometimes it doesn't output anything
The return code is always 0!
Screenshot
Running the code in a terminal (i.e. not in CLion itself)
However, the code outputs the numbers 0-999 perfectly when compiling and running the code using the terminal.
I have spent so much time on this thinking it was a problem with my code and a memory issue until I finally realised that this was just an issue with CLion.
OS: Ubuntu 14.04 LTS
Version: 2016.1
Build: #CL-145.258
Update
A suitable workaround is to run the code in debug mode (thanks to #olaf).
The consensus is that this is an IDE issue. Therefore, I have reported the bug.
A suitable workaround is to execute the code in debug mode (no breakpoint required).
I will update this question, as soon as this bug is fixed.
Update 1
WARNING: You should not change information in registry unless you have been asked specifically by JetBrains. Registry is not in the main menu for a reason! Use the following solution at your own risk!!!
JetBrains have contacted me and provided a suitable solution:
Go to the Find Action Dialog box (CTRL+SHIFT+A)
Search for "Registry..."
Untick run.processes.with.pty
Should then work fine!
Update 2
The bug has been added here:
https://youtrack.jetbrains.com/issue/CPP-6254
Feel free to upvote it!
I have a C++ program which works well when I compile with no additional options. However, whenever I use cmake -DCMAKE_BUILD_TYPE=Release there is a very specific part of the code which stops working.
Concretely, I have an interface for a Boost Fibonacci Heap. I am calling this function:
narrow_band_.push(myObject);
And this function does the following:
inline void myHeap::push (myStruct & c) {
handles_[c.getIndex()] = heap_.push(c);
}
where heap_ is:
boost::heap::fibonacci_heap<myStruct, boost::heap::compare<compare_func>> heap_;
For some reason the heap_size is not being modified, therefore the rest of the code does not work because the next step is to extract the minimum from the heap and it is always empty.
In Debug mode it works ok. Thank you for your help.
EDIT - Additional info
I have also found this problem: I have a set of code which do simple math operations. In Release mode the results are incorrect. If I just do cout of a couple of variables to check their values, the result changes, which is still incorrect but quite strange.
I solved the problem. It was funny but in this case it was not initialization/timing issues common in the Release mode. It was that the return statement was missing in a couple of functions. In debug mode the output was perfect but in the release mode that failed. I had warnings deactivated, that is why I did not see it before.
I'm not sure why, but for a mysterious reason my c++ application doesn't wait anymore when it reaches cvWaitKey(0) it just passes this line, like this function doesn't do anything!
I also tried cvWaitKey(100000) it doesn't work either...
void main() {
cvWaitKey(0);
return;
}
My project is a little complex, I'm using Visual Studio 2010 and It includes opencv ffmpeg pthread winsocks and some other libraries.
Can you guess why this happens?
Have you called cvNamedWindow yet? It will not work without cvNamedWindow.
I've had the issue myself a few times, but I can only speculate on what causes this. I can offer a work-around though:
while(1){
int key=cvWaitKey(10);
if(key==27) break;
}
This will block until ESC is pressed.
Why am I getting this behavior right after the if block? Am I missing something?
for (;;)
if (/*...*/)
{
// statements
}
// statements indented to match the if indentation instead of the for loop;
Visual Studio 2010 appears to be riddled with editor bugs. Indentation is particularly hosed.
Just wait until it starts moving your cursor to the beginning of the line every time you type a ':'.
If you close the file and reopen it that sometimes fixes the issue...for a little while anyway.
About the only way to keep VS doing indentation reasonably is to always use a block to enclose the statement controlled by a for, if, while, etc. In your case that would mean:
for (;;)
{
if (/* ... */)
{
// ...
}
}
// further statements here indented to match for loop.