Re: [GHC] #16078: Hide -Weverything warnings for GHCi internals

18 Jan 2019

      #16078: Hide -Weverything warnings for GHCi internals
-------------------------------------+-------------------------------------
        Reporter:  crockeea          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:
       Component:  GHCi              |              Version:  8.7
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  error/warning at compile-time      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by crockeea):

 * version:  8.6.2 => 8.7

Old description:
...
Consider
Bar.hs
{{{
module Bar where
}}}
Main.hs
{{{
import Bar
main :: IO ()
main = print ""
}}}
`stack ghci Main.hs --ghc-options -Weverything` produces
{{{
...
GHCi, version 8.6.2: http://www.haskell.org/ghc/  :? for help
<interactive>:1:1: warning: [-Wmissing-local-signatures]
    Polymorphic local binding with no type signature:
      _compileParsedExpr :: forall a. GHC.Types.IO a -> GHC.Types.IO a
<interactive>:1:1: warning: [-Wmissing-import-lists]
    The module `Prelude' does not have an explicit import list
Loaded GHCi configuration from C:\Users\ericcro\Desktop\VPC-Key-
Distribution\src\.ghci
<no location info>: warning: [-Wmissing-home-modules]
    Modules are not listed in command line but needed for compilation:
        Bar
[1 of 2] Compiling Bar              ( Bar.hs, interpreted )
...
}}}
Those three errors have nothing to do with my code, and seem to be
related to the internals of how GHCi works. It would be nice to hide all
three.
New description:

 Consider

 Bar.hs
 {{{
 module Bar where
 }}}

 Main.hs
 {{{
 import Bar

 main :: IO ()
 main = print ""
 }}}

 `ghci Main.hs -Weverything` produces

 {{{
 ...
 GHCi, version 8.7.20190113: http://www.haskell.org/ghc/  :? for help

 <interactive>:1:1: warning: [-Wmissing-local-signatures]
     Polymorphic local binding with no type signature:
       _compileParsedExpr :: forall a. GHC.Types.IO a -> GHC.Types.IO a

 <interactive>:1:1: warning: [-Wmissing-import-lists]
     The module `Prelude' does not have an explicit import list

 <no location info>: warning: [-Wmissing-home-modules]
     Modules are not listed in command line but needed for compilation:
         Bar
 [1 of 2] Compiling Bar              ( Bar.hs, interpreted )
 ...
 }}}

 Those three errors have nothing to do with my code, and seem to be related
 to the internals of how GHCi works. It would be nice to hide all three.

--

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16078#comment:4
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