# two classes of PRIO may not have the same number ----------------------------
tcc 2>&1
prio {
    class (1);
    class (1);
}
EOF
ERROR
<stdin>:2: duplicate class ID 0x1
# two classes of CBQ may not have the same number -----------------------------
tcc 2>&1
#include "tcngreg.def"

cbq (CBQ_PARAMS) {
    class (3,rate 2Mbps) {
	class (3,rate 1Mbps);
    }
}
EOF
ERROR
<stdin>:4: duplicate class ID 0x3
# variable scoping was outside-in ---------------------------------------------
tcc 2>/dev/null | sed '/.*classid /s///p;d'
$n = 2;
prio {
    $n = 1;
    class ($n)
	on fw element (1);
}
EOF
1:1
# existing variable did shadow forward-reference ------------------------------
tcc 2>/dev/null | sed '/.*classid /s///p;d'
$c = 5;
prio (priomap $c) {
    $c = class if 1;
}
EOF
1:1
# "drop" without selector prints warning --------------------------------------
echo 'prio { drop; }' | tcc 2>&1 >/dev/null
<stdin>:1: warning: ignoring "drop" without selector near ";"
