Debugging Tipps

Debugging could be confusing especially when interoperating across different languages. Thus, we utilize the following tools for our development process that can largely reveal some hidden information.

• gdb for low-level wrapper in C
• Debugger.jl for high-level wrapper within Julia

Calling lower-level wrapper functions in C

It is sometimes desirable to be able to call the lower-level functions directly in C. In order to do this, wee need to correctly link against the compiled debug mode Ginkgo dynamic library called libginkgod when using gcc.

Followingly is an example program where we accessed the underlying Ginkgo library through the implemented C API, resided within the Ginkgo library that we have cloned locally from Github.

//play_field.c
#include "/path/to/ginkgo/include/ginkgo/c_api.h"
#include <stdio.h>

int main() {

    ginkgo_version_get();

    // create an executor
    gko_executor exec = ginkgo_executor_omp_create();

    // create an dimensional object
    struct gko_dim2_st size = ginkgo_dim2_create(3, 4);

    // create a dense matrix
    gko_matrix_dense_f32 mat = ginkgo_matrix_dense_f32_create(exec, size);

    // printf() displays the string inside quotation
    printf("Number of stored elements: %zu\n", ginkgo_matrix_dense_f32_get_num_stored_elements(mat));
    return 0;
}

For the compilation process, this play_field.c file needs to be linked properly using the following command:

gcc -o play_field play_field.c -L/path/to/ginkgo/build/lib -lginkgod -Wl,-rpath=/path/to/ginkgo/build/lib -lginkgo_ompd -lginkgo_cudad -lginkgo_referenced -lginkgo_hipd -lginkgo_dpcppd -lginkgo_deviced /usr/lib/libhwloc.so /usr/lib/libmpi_cxx.so /usr/lib/libmpi.so

This is also helpful for verifying that the gcc compiler can properly proceed with our implemented C API.