debug

C/C++: How do you set GDB debug flag (-g) with cmake? 1

 in C / C++ / Programming  tagged cmake / debug / debug metadata / gdb / RelwithDebInfo / symbol table by

Solution 1: Modify the CMakeLists.txt file

Add the following line to your CMakeLists.txt file to set the compilation mode to Debug (non-optimized code with debug symbols):

set(CMAKE_BUILD_TYPE Debug)

Add the following line to your CMakeLists.txt file to set the compilation mode to RelWithDebInfo (optimized code with debug symbols):

set(CMAKE_BUILD_TYPE RelWithDebInfo)

Solution 2: Add a command line argument to your cmake command:

Modify as follows your cmake command to set the compilation mode to Debug (non-optimized code with debug symbols):

cmake -DCMAKE_BUILD_TYPE=Debug <path and other arguments>

Modify as follows your cmake command to set the compilation mode to RelWithDebInfo (optimized code with debug symbols):

cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo <path and other arguments>

Bonus material:

The difference between Debug and RelwithDebInfo modes is that RelwithDebInfo optimizes the code similarly to the behavior of Release mode. It produces fully optimized code, but also creates the symbol table and the debug metadata to give the debugger as much input as it is possible to map the execution back to the original code at any time.

Code build with RelwithDebInfo mode should not have it’s performance degraded in comparison to Release mode, as the symbol table and debug metadata that are generated do not live in the executable code section, so they should not affect the performance when the code is run without a debugger attached.

Debugging Trick Using Variadic Macros in C and C++

 in C / C++ / Programming  tagged C++ / cpp / debug / macro / variadic by

Following you can find a very practical trick that allows you to enable/disable all prints to the screen with as little effort as possible while not dramatically increasing the overall code size to do this.

For C:  Place on the top of your code or on a header file the following:

#define ENABLE_DEBUG

#ifdef ENABLE_DEBUG
    #define XDEBUG(...) printf(__VA_ARGS__)
#else
    #define XDEBUG(...)  /**/
#endif

and then inside the code whenever you want to print some debug information do as follows:

XDEBUG("Max Weight %d, Total Trips %d\n", minMax, trips);

For C++:  Place on the top of your code or on a header file the following:

#define ENABLE_DEBUG

#ifdef ENABLE_DEBUG
    #define XDEBUG cout
#else
    #define XDEBUG if(0) cerr
#endif

and then inside the code whenever you want to print some debug information do as follows:

XDEBUG << "We got " << disks << " disks\n";