[GHC] #16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: Component: GHCi | Version: 8.9 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC accepts Unknown/Multiple | invalid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- If you try something nonsensical like `id @Maybe` in GHCi 8.6.3, it will be properly rejected: {{{ $ ghci -XTypeApplications GHCi, version 8.6.3: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci λ> :t id @Maybe <interactive>:1:5: error: • Expecting one more argument to ‘Maybe’ Expected a type, but ‘Maybe’ has kind ‘* -> *’ • In the type ‘Maybe’ In the expression: id @Maybe }}} On GHC HEAD, however, this is seemingly accepted! {{{ $ ~/Software/ghc/inplace/bin/ghc-stage2 --interactive -XTypeApplications GHCi, version 8.9.20190224: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci λ> :t id @Maybe λ> }}} No error message, just... a newline. Quite bizarre. Even more bizarrely, this phenomenon doesn't appear to happen with `:kind`: {{{ λ> :set -XDataKinds -XPolyKinds λ> type Id (a :: k) = a λ> :k Id @Maybe <interactive>:1:5: error: • Expecting one more argument to ‘Maybe’ Expected a type, but ‘Maybe’ has kind ‘* -> *’ • In the first argument of ‘Id’, namely ‘Maybe’ In the type ‘Id @Maybe’ }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16376 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: Component: GHCi | Version: 8.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by int-index): * cc: int-index (added) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16376#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: Component: GHCi | Version: 8.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * cc: simonpj (added) Comment: This regression was introduced in commit [https://gitlab.haskell.org/ghc/ghc/commit/5c1f268e2744fab2d36e64c16385899545... 5c1f268e2744fab2d36e64c163858995451d7095] (`Fail fast in solveLocalEqualities`). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16376#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: Component: GHCi | Version: 8.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Combining this with `-fdefer-type-errors` leads to a panic: {{{ GHCi, version 8.9.20190227: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci λ> :set -XTypeApplications -fdefer-type-errors λ> f = id @Maybe <interactive>:2:9: warning: [-Wdeferred-type-errors] • Expecting one more argument to ‘Maybe’ Expected a type, but ‘Maybe’ has kind ‘* -> *’ • In the type ‘Maybe’ In the expression: id @Maybe In an equation for ‘f’: f = id @Maybe ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.9.20190227 for x86_64-unknown-linux): nameModule internal f_a1BS Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1159:37 in ghc:Outputable pprPanic, called at compiler/basicTypes/Name.hs:249:3 in ghc:Name }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16376#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: Component: GHCi | Version: 8.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): comment:3 reveals another bug: see #16404 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16376#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: highest | Milestone: 8.10.1 Component: GHCi | Version: 8.9 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC accepts | Test Case: invalid program | ghci/scripts/T16376 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => closed * testcase: => ghci/scripts/T16376 * resolution: => fixed * milestone: => 8.10.1 Comment: Fixed in [https://gitlab.haskell.org/ghc/ghc/commit/5be7ad7861c8d39f60b7101fd8d8e816ff... 5be7ad78]. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16376#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16376: GHCi HEAD silently accepts ill-kinded visible type applications with :type
-------------------------------------+-------------------------------------
Reporter: RyanGlScott | Owner: (none)
Type: bug | Status: closed
Priority: highest | Milestone: 8.10.1
Component: GHCi | Version: 8.9
Resolution: fixed | Keywords:
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: GHC accepts | Test Case:
invalid program | ghci/scripts/T16376
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
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