In /usr/bin/gccmakedep line 14:
LN="ln"
^-- SC2034: LN appears unused. Verify use (or export if used externally).


In /usr/bin/gccmakedep line 19:
trap "${RM} ${TMP}*; exit 1" 1 2 15
      ^---^ SC2064: Use single quotes, otherwise this expands now rather than when signalled.
            ^----^ SC2064: Use single quotes, otherwise this expands now rather than when signalled.


In /usr/bin/gccmakedep line 20:
trap "${RM} ${TMP}*; exit 0" 1 2 13
      ^---^ SC2064: Use single quotes, otherwise this expands now rather than when signalled.
            ^----^ SC2064: Use single quotes, otherwise this expands now rather than when signalled.
                                 ^-- SC2172: Trapping signals by number is not well defined. Prefer signal names.


In /usr/bin/gccmakedep line 30:
    if [ "$endmarker"x != x -a "$endmarker" = "$1" ]; then
                            ^-- SC2166: Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.


In /usr/bin/gccmakedep line 36:
		qarg=`echo "$1" | sed "s/'/'\\\\\\\\''/g"`
                     ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
		qarg=$(echo "$1" | sed "s/'/'\\\\\\\\''/g")


In /usr/bin/gccmakedep line 62:
				makefile="`cat ${TMP}arg`"
                                          ^-------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
				makefile="$(cat ${TMP}arg)"


In /usr/bin/gccmakedep line 67:
			    endmarker=`echo $1 | sed 's/^\-\-//'`
                                      ^-------------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                                            ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
			    endmarker=$(echo "$1" | sed 's/^\-\-//')

For more information:
  https://www.shellcheck.net/wiki/SC2034 -- LN appears unused. Verify use (or...
  https://www.shellcheck.net/wiki/SC2064 -- Use single quotes, otherwise this...
  https://www.shellcheck.net/wiki/SC2166 -- Prefer [ p ] && [ q ] as [ p -a q...