I am able to generate todo list for .sh and .py files using doxygen-bash.sed file and with below Doxyfile changes.
FILE_PATTERNS=.sh
FILTER_PATTERNS =
.sh=./doxygen-bash.sed
EXTENSION_MAPPING = sh=C

But i am not sure How to do the same for Makefile becase Makefile does not have extension.

Here is my Makefile:

include ../head.mk

define CUT_MODULES :=
uss_engine
endef

define TEST_MODULES +=
endef

define SEARCH_PATH :=
endef

@file

@todo MACH2-982 Remove this suppression.

CPPFLAGS += -Wno-error
CPPFLAGS += -include math.h

include ../foot.mk

The bold lines above my changes with doxygen-bash.sed file. But i am not what to do in Doxyfile changes.