Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the --+- Reporter: ChrisN | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler (Type checker) |Version: 7.6.1 Resolution: fixed| Keywords: Kinds, kindfunresult Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Compile-time crash | Difficulty: Unknown Testcase: typecheck/should_fail/T7368, T7368a | Blockedby: Blocking: |Related: --+- Changes (by igloo): * status: merge = closed * resolution: = fixed Comment: Merged as c4b2ac3775323948b7a6abdb241a4ad02afa7141 -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the
+---
Reporter: ChrisN | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) | Version: 7.6.1
Keywords: Kinds, kindfunresult | Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time crash
Difficulty: Unknown |Testcase:
typecheck/should_fail/T7368
Blockedby: |Blocking:
Related: |
+---
Comment(by simonpj@…):
commit be5cc2e33aa8e54299527af9b91e659d54c4cde5
{{{
Author: Simon Peyton Jones simo...@microsoft.com
Date: Wed Dec 19 23:49:47 2012 +
Fix TcUnify.matchExpectedTyConApp so that it returns types of
compatible kinds
This fixes Trac #7368. The problem was that we were matching
Bad w ~ f (Bad f)
where (f :: * - *). Thta leads to (w ~ Bad f), which is
ill-kinded, but matchExpectedTyConApp was returning the (Bad f)
as the argument type, and that was being used to instanatiate
w in the data constructor type, which is very bad.
The code also becomes simpler and easier to understand, which is
an excellent thing.
compiler/typecheck/TcUnify.lhs | 81
1 files changed, 40 insertions(+), 41 deletions(-)
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:6
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Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the +--- Reporter: ChrisN | Owner: Type: bug | Status: merge Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.6.1 Keywords: Kinds, kindfunresult | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time crash Difficulty: Unknown |Testcase: typecheck/should_fail/T7368, T7368a Blockedby: |Blocking: Related: | +--- Changes (by simonpj): * status: new = merge * testcase: typecheck/should_fail/T7368 = typecheck/should_fail/T7368, T7368a Comment: Fixed! New test case added. Thanks for reporting this. Simon -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the
+---
Reporter: ChrisN | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) | Version: 7.6.1
Keywords: Kinds, kindfunresult | Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time crash
Difficulty: Unknown |Testcase:
typecheck/should_fail/T7368
Blockedby: |Blocking:
Related: |
+---
Comment(by arkeet):
I don't know if this should be a separate bug, but the following (ill-
typed) code produces the same error, both on 7.6.1 and on HEAD:
{{{
{-# LANGUAGE Rank2Types #-}
newtype Bad f = Bad (forall a. (f a - a))
fun :: f (Bad f) - Bad f
fun (Bad x) = Bad x
}}}
{{{
[1 of 1] Compiling Main ( bad.hs, bad.o )
ghc: panic! (the 'impossible' happened)
(GHC version 7.7.20121127 for x86_64-unknown-linux):
kindFunResult ghc-prim:GHC.Prim.*{(w) tc 34d}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:5
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Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the +--- Reporter: ChrisN | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.6.1 Keywords: Kinds, kindfunresult | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time crash Difficulty: Unknown |Testcase: typecheck/should_fail/T7368 Blockedby: |Blocking: Related: | +--- Comment(by simonpj): Ugh. So it does. I'll investigate. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the
+---
Reporter: ChrisN | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler (Type checker)
Version: 7.7 | Keywords: Kinds, kindfunresult
Os: Unknown/Multiple| Architecture: Unknown/Multiple
Failure: Compile-time crash | Testcase:
Blockedby: | Blocking:
Related: |
+---
Comment(by ChrisN):
Sorry, some odd formatting there.
That code should be:
{{{
module Test where
f = b (l () )
l :: b a - c b
l = undefined
b :: (a - b) - c
b = undefined
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:1
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Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the
+---
Reporter: ChrisN | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) | Version: 7.7
Keywords: Kinds, kindfunresult | Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time crash
Difficulty: Unknown |Testcase:
Blockedby: |Blocking:
Related: |
+---
Changes (by simonpj):
* difficulty: = Unknown
Old description:
This code:
-
f = b (l () )
l :: b a - c b
l = undefined
b :: (a - b) - c
b = undefined
-
Produces the following panic:
/tmp/Test.hs:4:10:
Couldn't match kind `* - *' with `*'
Expected type: a0 - b0
Actual type: a0 - b0
Kind incompatibility when matching types:
b_k :: * - *
b0 :: *
In the return type of a call of `l'
In the first argument of `b', namely `(l ())'
/tmp/Test.hs:4:13:ghc: panic! (the 'impossible' happened)
(GHC version 7.7.20120909 for x86_64-unknown-linux):
kindFunResult ghc-prim:GHC.Prim.*{(w) tc 34d}
I don't think this is the same as #6039 since that test code produces a
parse error when I try to compile it (and it is listed as fixed).
New description:
This code:
{{{
f = b (l () )
l :: b a - c b
l = undefined
b :: (a - b) - c
b = undefined
}}}
Produces the following panic:
{{{
/tmp/Test.hs:4:10:
Couldn't match kind `* - *' with `*'
Expected type: a0 - b0
Actual type: a0 - b0
Kind incompatibility when matching types:
b_k :: * - *
b0 :: *
In the return type of a call of `l'
In the first argument of `b', namely `(l ())'
/tmp/Test.hs:4:13:ghc: panic! (the 'impossible' happened)
(GHC version 7.7.20120909 for x86_64-unknown-linux):
kindFunResult ghc-prim:GHC.Prim.*{(w) tc 34d}
}}}
I don't think this is the same as #6039 since that test code produces a
parse error when I try to compile it (and it is listed as fixed).
--
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:2
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Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the
+---
Reporter: ChrisN | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) | Version: 7.6.1
Keywords: Kinds, kindfunresult | Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time crash
Difficulty: Unknown |Testcase:
typecheck/should_fail/T7368
Blockedby: |Blocking:
Related: |
+---
Changes (by simonpj):
* testcase: = typecheck/should_fail/T7368
* version: 7.7 = 7.6.1
Comment:
Good bug. Yes 7.6.1 fails, thus
{{{
T7368.hs:3:10:
Couldn't match kind `* - *' with `*'
Expected type: a0 - b0
Actual type: a0 - b0
Kind incompatibility when matching types:
b_w :: * - *
b0 :: *
In the return type of a call of `l'
In the first argument of `b', namely `(l ())'
T7368.hs:3:13:ghc-stage1: panic! (the 'impossible' happened)
(GHC version 7.6.1.20121011 for x86_64-unknown-linux):
kindFunResult ghc-prim:GHC.Prim.*{(w) tc 34d}
}}}
However HEAD (will be 7.8) is (happily) ok:
{{{
T7368.hs:3:10:
Couldn't match kind `* - *' with `*'
When matching types
c0 :: (* - *) - *
(-) a0 :: * - *
Expected type: a0 - b0
Actual type: c0 b1
In the return type of a call of `l'
Probable cause: `l' is applied to too many arguments
In the first argument of `b', namely `(l ())'
In the expression: b (l ())
T7368.hs:3:13:
Couldn't match type `()' with `b0 a1'
Expected type: b1 a1
Actual type: ()
In the first argument of `l', namely `()'
In the first argument of `b', namely `(l ())'
In the expression: b (l ())
}}}
I don't know where exactly the problem lies in 7.6, and I'm very swamped,
so I'm going to leave this open and unfixed. If it turns out to bite some
mission-critical package I can look into fixing it in 7.6, I'd prefer not
to have to do that.
I have added a regression test though.
Simon
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:3
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Re: [GHC] #7368: kindFunResult panic in the
#7368: kindFunResult panic in the +--- Reporter: ChrisN | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.6.1 Keywords: Kinds, kindfunresult | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time crash Difficulty: Unknown |Testcase: typecheck/should_fail/T7368 Blockedby: |Blocking: Related: | +--- Comment(by ChrisN): Fine, I don't think it's a big deal anyway since I can only get it to crop up in programs with kind errors. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7368#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
