/usr/bin/gccmakedep is in xutils-dev 1:7.7+5ubuntu1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | #!/bin/sh
#
# makedepend which uses 'gcc -M'
#
# $XFree86: xc/config/util/gccmdep.cpp,v 3.10tsi Exp $
#
# Based on mdepend.cpp and code supplied by Hongjiu Lu <hjl@nynexst.com>
#
TMP=mdep$$.tmp
CC="gcc"
RM="rm -f"
LN="ln"
MV="mv"
${RM} ${TMP}
trap "${RM} ${TMP}*; exit 1" 1 2 15
trap "${RM} ${TMP}*; exit 0" 1 2 13
files=
makefile=
endmarker=
magic_string='# DO NOT DELETE'
append=n
args=
while [ $# != 0 ]; do
    if [ "$endmarker"x != x -a "$endmarker" = "$1" ]; then
	endmarker=
    else
	case "$1" in
	    -D*|-I*|-U*)
# arg may contain single quotes
		qarg=`echo "$1" | sed "s/'/'\\\\\\\\''/g"`
                args="$args '$qarg'"
		;;
	    -g*|-O*)
		;;
	    *)
		if [ "$endmarker"x = x ]; then
		    case $1 in
# ignore these flags
			-w|-o|-cc)
			    shift
			    ;;
			-v)
			    ;;
			-s)
			    magic_string="$2"
			    shift
			    ;;
			-f*)
			    if [ "$1" = "-f-" ]; then
				makefile="-"
			    elif [ "$1" = "-f" ]; then
				makefile="$2"
				shift
			    else
				echo "$1" | sed 's/^\-f//' >${TMP}arg
				makefile="`cat ${TMP}arg`"
				rm -f ${TMP}arg
			    fi
			    ;;
			--*)
			    endmarker=`echo $1 | sed 's/^\-\-//'`
			    if [ "$endmarker"x = x ]; then
				endmarker="--"
			    fi
			    ;;
			-a)
			    append=y
			    ;;
			-*)
			    echo "Unknown option '$1' ignored" 1>&2
			    ;;
			*)
# filename may contain blanks
			    files="$files '$1'"
			    ;;
		    esac
		fi
		;;
	esac
    fi
    shift
done
if [ x"$files" = x ]; then
# Nothing to do
    exit 0
fi
case "$makefile" in
    '')
	if [ -r makefile ]; then
	    makefile=makefile
	elif [ -r Makefile ]; then
	    makefile=Makefile
	else
	    echo 'no makefile or Makefile found' 1>&2
	    exit 1
	fi
	;;
esac
if [ X"$makefile" != X- ]; then
    if [ x"$append" = xn ]; then
        sed -e "/^$magic_string/,\$d" < $makefile > $TMP
        echo "$magic_string" >> $TMP
    else
        cp $makefile $TMP
    fi
fi
CMD="$CC -M $args $files"
if [ X"$makefile" != X- ]; then
    CMD="$CMD >> $TMP"
fi
# Do not wildcard expand '*' in args
eval "$CMD"
if [ X"$makefile" != X- ]; then
    $RM ${makefile}.bak
    $MV $makefile ${makefile}.bak
    $MV $TMP $makefile
fi
$RM ${TMP}*
exit 0
 |