optclash

#!/bin/sh

export LC_ALL=C

defname=libtcc.c

# $1 is the line number, $2... is the actual source line
extract_opts() { awk '/tcc_options\[\]/ {x=1}; x; x && $2~/^}/ {exit}'; }

case $1 in -h|--help)
    echo "Usage: $0 [INFILE]"
    echo "Detect tcc_options[] clashes in $defname-like INFILE."
    echo "If INFILE is missing, use $defname at the same dir as this script."
    echo "Clashes are reported as longer-overrides, or longer-unreachable."
    exit
esac

f=${1-$(dirname "$0")/$defname}
[ -r "$f" ] || { >&2 echo "$0: can't read -- $f"; exit 1; }

nl -b a <"$f" | extract_opts | tr \" ' ' | awk '$2=="{"' | sort -b -k 3 |
# "<line-num> { <unquoted-opt> <rest-of-line>"  sorted-up by opt
# unavoidable O(N^2). the sort simplifies the awk code - only test prior opts.
awk '
    {
        n=$1; opt=$3; h=/HAS_ARG/
        for (pn in prevs) {  # pn: line-num
            po = prevs[pn]   # po: opt-with-has-arg
            if (index(opt,po) == 1) {
                clash=1
                printf("-%s%s (%d) %s -%s... (%s)\n", opt,h?"...":"",n,
                       n>pn? "is not reachable! by":"overrides", po,pn)
            }
        }
    }
    h   {prevs[n] = opt}
    END {if (clash) exit 1; print "no clashes"}
'