Maybe use Perl to expand your source code instead of C macros? I'm sure it wouldn't be too hard to search and replace the expression.

Most likely you want to look at Text::Balanced to parse the bracketed expressions. The rest should be some basic string manipulation.

If you have concrete problems with your Perl code, please post it and some small but relevant input and output data, and how it fails for you.

i want to define a macro where i can print a variable's name and value

#define DBG(x) printf("DEBUG >> "#x" == %d\n",(x))
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See Quoting macro arguments

Example:

#include <stdio.h>
#define DBG(x) printf("DEBUG >> "#x" == %d\n",(x))

int main() {
    int u4_heap_mem_size = 8890;

    DBG(u4_heap_mem_size+1);    // prints  DEBUG >> u4_heap_mem_size+1
+ == 8891
    
    return 0;
}
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Removed because not really answering the question