Re: [GHC] #3449: Unavoidable unused bindings warnings in boot files
#3449: Unavoidable unused bindings warnings in boot files ---+ Reporter: heatsink | Owner: igloo Type: bug | Status: closed Priority: normal| Milestone: 6.14.1 Component: Compiler |Version: 6.10.4 Resolution: fixed | Keywords: Difficulty: Unknown | Os: Unknown/Multiple Testcase: T3449 | Architecture: Unknown/Multiple Failure: None/Unknown | ---+ Changes (by igloo): * status: new = closed * testcase: = T3449 * resolution: = fixed Comment: Fixed. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3449#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3449: Unavoidable unused bindings warnings in boot files
#3449: Unavoidable unused bindings warnings in boot files -+-- Reporter: heatsink |Owner: igloo Type: bug | Status: new Priority: normal|Milestone: 6.14.1 Component: Compiler | Version: 6.10.4 Keywords:| Difficulty: Unknown Os: Unknown/Multiple | Testcase: Architecture: Unknown/Multiple | Failure: None/Unknown -+-- Changes (by igloo): * owner: = igloo * failure: = None/Unknown -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3449#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #3449: Unavoidable unused bindings warnings in boot files
#3449: Unavoidable unused bindings warnings in boot files -+-- Reporter: heatsink |Owner: Type: bug | Status: new Priority: normal|Milestone: 6.14.1 Component: Compiler | Version: 6.10.4 Severity: minor | Resolution: Keywords:| Difficulty: Unknown Testcase:| Os: Unknown/Multiple Architecture: Unknown/Multiple | -+-- Changes (by igloo): * difficulty: = Unknown * milestone: = 6.14.1 Comment: Thanks for the report. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3449#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #3449: Unavoidable unused bindings warnings in boot files
#3449: Unavoidable unused bindings warnings in boot files
-+--
Reporter: heatsink | Owner:
Type: bug | Status: new
Priority: normal| Component: Compiler
Version: 6.10.4| Severity: minor
Keywords:| Testcase:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
-+--
The {{{-fwarn-unused-binds}}} flag produces warnings for bindings that
cannot, in fact, be deleted from hs-boot files. It would be nice not to
see these warnings. Definitions in .hs-boot files must match the
definitions in .hs files, but .hs-boot files don't necessarily use or
export the same identifiers that the .hs file does.
Running {{{ghc -c A.hs-boot -fwarn-unused-binds}}} produces warnings for
this hs-boot file, regardless of whether the identifiers are exported in
the hs file.
{{{
{- A.hs-boot -}
{-# OPTIONS_GHC -XTypeFamilies #-} -- to demonstrate associated type
warnings
module A(Foo, HasFoo) where
newtype Foo = Foo {unFoo :: Int}
class HasFoo a where
data Foo' a
getFoo :: a - Foo
}}}
For identifiers defined on the RHS of an equal sign or 'where'---namely,
data constructors, field names, class methods, and associated types---I
suggest silencing unused binding warnings in the boot file. The rationale
is that you should be allowed to copy an entire definition into the boot
file, and regard a binding as unused only if it appears unused in the .hs
file.
See also #3283.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/3449
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler___
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: Unused bindings
Thanks, this is a known shortcoming. We'll either fix the docs or the implementation! --Sigbjorn Sven Panne writes: GHC-3.01 can generate some really useful warnings, but some of those generated by -fwarn-unused-binds (which is switched on via -Wall, too) are plainly wrong. Silly, but short example: .. -- Foo.hs -- module Foo(Bar(..)) where data Bar = MkBar instance Show Bar where showsPrec _ = baz baz :: Bar - ShowS baz MkBar = showString "MkBar" --- panne@liesl: ghc -fwarn-unused-binds -c Foo.hs Foo.hs:9: Warning: `baz' is bound but not used ghc: module version changed to 1; reason: no old .hi file GHC doesn't seem to take instance declarations into account when complaining... :-(
