Q: Is there any way to list a macro in core files using GDB like if in a core file, we have a function then we list the function like
list <function_name>

but while doing the same thing with a macro it's stating like 
Function <macro_name> not defined.

can somebody help ?

A: 
list a macro in core files using GDB

Note that neither function names, nor macro names are contained in the core file. They are contained in the executable.
To allow GDB to show macros, you must compile your executable with appropriate level of debug info (-g3 for GCC if using DWARF platform), then use macro expand GDB command.
Note that recompiling executable may render the existing core unusable, unless you can rebuild it from exact same sources. In particular, if the original executable was compiled with optimization (e.g. with -O2), then you must use the exact same options (just add -g3 to the compile lines).
