Skip to content

GitLab

  • Projects
  • Groups
  • Snippets
  • Help
    • Loading...
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
  • Sign in / Register
GHC
GHC
  • Project overview
    • Project overview
    • Details
    • Activity
    • Releases
  • Repository
    • Repository
    • Files
    • Commits
    • Branches
    • Tags
    • Contributors
    • Graph
    • Compare
    • Locked Files
  • Issues 4,320
    • Issues 4,320
    • List
    • Boards
    • Labels
    • Service Desk
    • Milestones
    • Iterations
  • Merge Requests 359
    • Merge Requests 359
  • Requirements
    • Requirements
    • List
  • CI / CD
    • CI / CD
    • Pipelines
    • Jobs
    • Schedules
  • Security & Compliance
    • Security & Compliance
    • Dependency List
    • License Compliance
  • Operations
    • Operations
    • Incidents
    • Environments
  • Analytics
    • Analytics
    • CI / CD
    • Code Review
    • Insights
    • Issue
    • Repository
    • Value Stream
  • Wiki
    • Wiki
  • Snippets
    • Snippets
  • Members
    • Members
  • Collapse sidebar
  • Activity
  • Graph
  • Create a new issue
  • Jobs
  • Commits
  • Issue Boards
  • Glasgow Haskell Compiler
  • GHCGHC
  • Issues
  • #2213

Closed
Open
Opened Apr 11, 2008 by dons@trac-dons

Confusing flags for rewrite rules

Functions exported via rewrite rules are incorrectly flagged as "defined but not used" when -Wall is enabled:

module M ({- rules -}) where

eq :: Eq a => a -> a -> Bool
eq = (==)

{-# RULES
    "rule 1" forall x. x == y = y `eq` x
  #-}

Will emit a bogus:

  M.hs:4:0: Warning: Defined but not used: `eq'
Trac metadata
Trac field Value
Version 6.8.2
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC rules, warnings
Operating system Unknown
Architecture Unknown
Edited Mar 09, 2019 by Simon Peyton Jones
Assignee
Assign to
6.10 branch
Milestone
6.10 branch
Assign milestone
Time tracking
None
Due date
None
Reference: ghc/ghc#2213