[GHC] #9417: Pattern synonyms across modules broken in Haddock

6 Aug 2014

      #9417: Pattern synonyms across modules broken in Haddock
-------------------------------------+-------------------------------------
       Reporter:  Fuuzetsu           |                   Owner:
           Type:  bug                |                  Status:  new
       Priority:  normal             |               Milestone:
      Component:  Compiler           |                 Version:  7.9
       Keywords:                     |        Operating System:
   Architecture:  Unknown/Multiple   |  Unknown/Multiple
     Difficulty:  Unknown            |         Type of failure:
     Blocked By:                     |  None/Unknown
Related Tickets:                     |               Test Case:
                                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
 Create modules as follows

 {{{#!hs
 -- PatSymDef.hs

 {-# Language PatternSynonyms #-}
 module PatSymDef where

 pattern Some a = Just a
 }}}

 {{{#!hs
 -- PatSymUse.hs

 {-# Language PatternSynonyms #-}
 module PatSymUse where

 import PatSymDef

 f :: Maybe Int -> Int
 f (Some a) = a
 f Nothing = 0
 }}}

 Then run Haddock against them:

 {{{
 [nix-shell:~/programming/haddock]$ ./dist/build/haddock/haddock -h
 /tmp/PatSymUse.hs /tmp/PatSymDef.hs  -o /tmp
 Haddock coverage:
 Warning: Not found in environment: Some
   50% (  1 /  2) in 'PatSymDef'

 /tmp/PatSymUse.hs:9:4:
     Can't find interface-file declaration for data constructor Some
       Probable cause: bug in .hi-boot file, or inconsistent .hi file
       Use -ddump-if-trace to get an idea of which file caused the error
     In the pattern: Some a
     In an equation for ‘f’: f (Some a) = a
 }}}

 Here with -ddump-if-trace:

 {{{
 [nix-shell:~/programming/haddock]$ ./dist/build/haddock/haddock -h
 /tmp/PatSymUse.hs /tmp/PatSymDef.hs -o /tmp --optghc='-ddump-if-trace'
 Haddock coverage:
 Considering whether to load base:Prelude
 Reading interface for base:Prelude;
     reason: Prelude is directly imported
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/Prelude.hi
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/Prelude.dyn_hi
 updating EPS_
 updating EPS_
 Considering whether to load base:GHC.Base {- SYSTEM -}
 Reading interface for base:GHC.Base;
     reason: Loading orphan modules (base:GHC.Base)
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/GHC/Base.hi
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/GHC/Base.dyn_hi
 updating EPS_
 Considering whether to load base:GHC.Float {- SYSTEM -}
 Reading interface for base:GHC.Float;
     reason: Loading orphan modules (base:GHC.Float)
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/GHC/Float.hi
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/GHC/Float.dyn_hi
 updating EPS_
 Considering whether to load base:GHC.Real {- SYSTEM -}
 Reading interface for base:GHC.Real;
     reason: Loading orphan modules (base:GHC.Real)
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/GHC/Real.hi
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/GHC/Real.dyn_hi
 updating EPS_
 loadHiBootInterface main@main:PatSymDef
 Considering whether to load base:Data.Maybe {- SYSTEM -}
 Reading interface for base:Data.Maybe;
     reason: The name ‘Data.Maybe.Just’ is mentioned explicitly
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/Data/Maybe.hi
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/base_DiPQ1siqG3SBjHauL3L03p/Data/Maybe.dyn_hi
 updating EPS_
 Starting fork { Declaration for Maybe
 Loading decl for Data.Maybe.Maybe
 updating EPS_
 Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -}
 Reading interface for ghc-prim:GHC.Prim;
     reason: Need home interface for wired-in thing *
 updating EPS_
 Start interface-file tc_con_decl Nothing
 Done interface-file tc_con_decl Data.Maybe.Nothing
 Start interface-file tc_con_decl Just
 Done interface-file tc_con_decl Data.Maybe.Just
 tcIfaceDecl4 Data.Maybe.Maybe
 } ending fork Declaration for Maybe
 Starting fork { Constructor Data.Maybe.Nothing
 } ending fork Constructor Data.Maybe.Nothing
 Starting fork { Constructor Data.Maybe.Just
 } ending fork Constructor Data.Maybe.Just

 ==================== Interface statistics ====================
 Renamer stats: 6 interfaces read
                1 type/class/variable imported, out of 776 read
                0 instance decls imported, out of 42 read
                0 rule decls imported, out of 53 read

 Need decl for PatSymDef.Some
 Considering whether to load main@main:PatSymDef {- SYSTEM -}
 Warning: Not found in environment: Some
   50% (  1 /  2) in 'PatSymDef'
 Considering whether to load base:Prelude
 Considering whether to load main@main:PatSymDef
 updating EPS_
 Considering whether to load base:GHC.Base {- SYSTEM -}
 Considering whether to load base:GHC.Float {- SYSTEM -}
 Considering whether to load base:GHC.Real {- SYSTEM -}
 loadHiBootInterface main@main:PatSymUse
 Considering whether to load base:Data.Maybe {- SYSTEM -}
 Considering whether to load ghc-prim:GHC.Types {- SYSTEM -}
 Reading interface for ghc-prim:GHC.Types;
     reason: The name ‘GHC.Types.Int’ is mentioned explicitly
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/ghcpr_BE58KUgBe9ELCsPXiJ1Q2r/GHC/Types.hi
 readIFace /nix/store/m347lhn3g6sh2s9pv7kz68qs2jyhzphg-
 ghc-7.9.20140805/lib/ghc-7.9.20140805/ghcpr_BE58KUgBe9ELCsPXiJ1Q2r/GHC/Types.dyn_hi
 updating EPS_
 Considering whether to load ghc-prim:GHC.Types {- SYSTEM -}
 Considering whether to load main@main:PatSymDef {- SYSTEM -}
 Considering whether to load base:Data.Maybe {- SYSTEM -}
 Considering whether to load ghc-prim:GHC.Types {- SYSTEM -}
 Considering whether to load ghc-prim:GHC.Types {- SYSTEM -}
 Need decl for PatSymDef.Some
 Considering whether to load main@main:PatSymDef {- SYSTEM -}

 /tmp/PatSymUse.hs:9:4:
     Can't find interface-file declaration for data constructor Some
       Probable cause: bug in .hi-boot file, or inconsistent .hi file
       Use -ddump-if-trace to get an idea of which file caused the error
     In the pattern: Some a
     In an equation for ‘f’: f (Some a) = a
 }}}

 Originally reported to me against Haddock 2.14.3, GHC 7.8.3 and I can
 confirm both there and on yesterday's GHC HEAD.

 It'd be great if whoever is involved with pattern synonyms could take a
 look.

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9417
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