compiler warnings on the buildfarm

What is the official stance on handling compiler warnings?
I got a bit curious today on how many warnings our builds are generating
on the buildfarm.
I have hacked up a small script that (in a very primitive way) parses
the "make" stage logfiles of all unix boxes reporting on HEAD and prints
the number of lines that appear to be either diagnostics or warnings
emited during a build with the following results:

animal: mongoose warnings: 2379
animal: warthog warnings: 1368
animal: kudu warnings: 748
animal: turnip_moth warnings: 736
animal: gypsy_moth warnings: 736
animal: winter_moth warnings: 700
animal: ghost_moth warnings: 700
animal: dot_moth warnings: 700
animal: codlin_moth warnings: 700
animal: dugong warnings: 371
animal: emu warnings: 265
animal: orangutan warnings: 198
animal: spoonbill warnings: 126
animal: zebra warnings: 124
animal: tucuxi warnings: 124
animal: lionfish warnings: 87
animal: wildebeest warnings: 77
animal: rook warnings: 76
animal: rosella warnings: 74
animal: dragonfly warnings: 72
animal: wombat warnings: 71
animal: Shad warnings: 71
animal: quagga warnings: 71
animal: caracara warnings: 71
animal: bobcat warnings: 71
animal: barasingha warnings: 71
animal: grebe warnings: 50
animal: eel warnings: 43
animal: thrush warnings: 32
animal: salamander warnings: 27
animal: clownfish warnings: 26
animal: osprey warnings: 24
animal: luna_moth warnings: 15
animal: emperor_moth warnings: 15
animal: canary warnings: 14
animal: impala warnings: 9
animal: jackal warnings: 7
animal: bear warnings: 6
animal: viper warnings: 5
animal: cuckoo warnings: 5
animal: cardinal warnings: 5
animal: boodie warnings: 5
animal: aubrac warnings: 5
animal: sponge warnings: 3
animal: dungbeetle warnings: 3
animal: tapir warnings: 0
animal: platypus warnings: 0
animal: ermine warnings: 0

a lot of those are simply noise (like the LOOP VECTORIZED stuff from the
icc boxes or the "statement not reached" spam from the sun compilers)
but others might indicate real issues.
To find warnings that might be a real problem we might want to look into
suppressing those - if possible - using compiler switches.

comments ?

Stefan