#8258: GHC accepts `data Foo where` in H2010 mode -------------------------------------+------------------------------------- Reporter: hvr | Owner: sighingnow Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.0.4 (Parser) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC accepts | Test Case: parser/T8258, invalid program | parser/T8258NoGADTs Blocked By: | Blocking: 11384 Related Tickets: | Differential Rev(s): Phab:D4350 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"8936ab69d18669bab3ca4edf40458f88ae5903f0/ghc" 8936ab6/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="8936ab69d18669bab3ca4edf40458f88ae5903f0" Raise parse error for `data T where`. Empty GADTs data declarations can't be identified in type checker. This patch adds additional checks in parser and raise a parse error when encounter empty GADTs declarations but extension `GADTs` is not enabled. Only empty declarations are checked in parser to avoid affecting existing error messages related to missing GADTs extension. This patch should fix issue 8258. Signed-off-by: HE, Tao <sighingnow@gmail.com> Test Plan: make test TEST="T8258 T8258NoGADTs" Reviewers: bgamari, mpickering, alanz, RyanGlScott Reviewed By: bgamari, RyanGlScott Subscribers: adamse, RyanGlScott, rwbarton, thomie, mpickering, carter GHC Trac Issues: #8258 Differential Revision: https://phabricator.haskell.org/D4350 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8258#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler