Flag to suppress orphan instance warnings

Since everyone is all abuzz about orphan instances: can we have a flag to disable orphan instance warnings? -fno-warn-orphan-instances apparently doesn't exist. It's not a big deal, but I don't care about the warnings and would rather not expend brain cycles on ignoring them.

Trac metadata

Trac field	Value
Version	6.8.3
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
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Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown

changed weight to 5

added Tfeature request Trac import labels

closed

You're in luck, -fno-warn-orphans already exists!

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Trac field	Value
Resolution	Unresolved → ResolvedWorksForMe

reopened

Thanks -- serves me right for not reading the manual. However, there's still a documentation problem: Section 5.6.12 of the users' guide mentions the flag -fwarn-orphan-modules, which doesn't seem to exist. I'm not sure whether that's supposed to mean the same thing as -fwarn-orphans, but in any case, that should be fixed. (I would fix it myself if all of my source trees weren't currently hosed.)

Trac metadata

Trac field	Value
Type	FeatureRequest → Bug
Resolution	ResolvedWorksForMe → Unresolved
Component	Compiler → Documentation

added Tbug documentation labels and removed Tfeature request label

I take it back: -fno-warn-orphans seems to be silently ignored (if I pass it, I still see the orphan warning messages), so that should be fixed too.

Trac metadata

Trac field	Value
Component	Documentation → Compiler

Replying to [ticket:2515#comment:25198 tim]:

I take it back: -fno-warn-orphans seems to be silently ignored (if I pass it, I still see the orphan warning messages), so that should be fixed too.

Hmm, that's interesting, it works for me in 6.8.2, both when specified on the ghc command line and in a pragma {-# OPTIONS_GHC -fno-warn-orphans #-}.

Replying to [ticket:2515#comment:25199 duncan]:

Replying to [ticket:2515#comment:25198 tim]:

I take it back: -fno-warn-orphans seems to be silently ignored (if I pass it, I still see the orphan warning messages), so that should be fixed too.

Hmm, that's interesting, it works for me in 6.8.2, both when specified on the ghc command line and in a pragma {-# OPTIONS_GHC -fno-warn-orphans #-}.

I realized my problem -- I had an OPTIONS_GHC pragma in the module I was compiling, which included -Wall, and was giving -fno-warn-orphans on the command line, so -Wall was overriding -fno-warn-orphans. I find this a little confusing, but I guess it must be documented somewhere.

Anyway, my "...still a documentation problem" comment still applies.

Trac metadata

Trac field	Value
Component	Compiler → Documentation

closed

Right, good point. I've fixed the docs; pushing shortly.

Simon

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

Trac metadata

Trac field	Value
Architecture	Unknown → Unknown/Multiple

Trac metadata

Trac field	Value
Operating system	Unknown → Unknown/Multiple

mentioned in issue #3820 (closed)

Trac metadata

Trac field	Value
TypeOfFailure	- → OtherFailure

Trac metadata

Trac field	Value
Related	- → #10150

added Tfeature request label

added Pnormal label