[GHC] #13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple PatternSynonyms | Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- `purescript-0.10.7` fails to build with GHC HEAD at the moment due to an apparent regression in the way pattern synonyms and overloaded strings interact. Here is a simplified example: {{{#!hs {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE PatternSynonyms #-} module Bug where import Data.ByteString newtype ProperName = ProperName { runProperName :: ByteString -- purescript actually uses the Text type, but this works -- just as well for the purposes of illustrating the bug } newtype ModuleName = ModuleName [ProperName] pattern TypeDataSymbol :: ModuleName pattern TypeDataSymbol = ModuleName [ProperName "Type",ProperName "Data", ProperName "Symbol"] }}} Compiling this with GHC 7.10.3 or 8.0.2 works without issue. In GHC HEAD, if you compile this with optimization enabled, it'll trigger a GHC panic: {{{ $ ~/Software/ghc5/inplace/bin/ghc-stage2 -O1 -fforce-recomp Bug.hs [1 of 1] Compiling Bug ( Bug.hs, Bug.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.1.20170303 for x86_64-unknown-linux): isUnliftedType r_a28T :: TYPE rep_a28S Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1191:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1195:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1961:10 in ghc:Type }}} The presence of optimization is crucial for reproducing this bug, as compiling it with `-O0` does not trigger the panic. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Aha. Thanks. Easy fix validating now. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD
-------------------------------------+-------------------------------------
Reporter: RyanGlScott | Owner: (none)
Type: bug | Status: new
Priority: highest | Milestone: 8.2.1
Component: Compiler | Version: 8.1
Resolution: | Keywords:
| PatternSynonyms
Operating System: Unknown/Multiple | Architecture:
Type of failure: Compile-time | Unknown/Multiple
crash or panic | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Simon Peyton Jones
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: fixed | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash or panic | polykinds/T13394 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * testcase: => polykinds/T13394 * resolution: => fixed -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash or panic | polykinds/T13394 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: closed => new * resolution: fixed => Comment: Thanks, Simon. But you didn't include the original program as the test case! Rather, you included a slightly tweaked program that doesn't have as many list elements in `TypeDataSymbol`. This is crucial, as the original program still fails with a GHC panic even after 8e053700f9357c1b9030c406130062795ae5015c: {{{ $ ~/Software/ghc2/inplace/bin/ghc-stage2 -O1 -fforce-recomp Bug.hs [1 of 1] Compiling Bug ( Bug.hs, Bug.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.1.20170307 for x86_64-unknown-linux): runtimeRepPrimRep typePrimRep (r_a28P :: TYPE rep_a28O) rep_a28O Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1191:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1195:37 in ghc:Outputable pprPanic, called at compiler/simplStg/RepType.hs:360:5 in ghc:RepType }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD
-------------------------------------+-------------------------------------
Reporter: RyanGlScott | Owner: (none)
Type: bug | Status: new
Priority: highest | Milestone: 8.2.1
Component: Compiler | Version: 8.1
Resolution: | Keywords:
| PatternSynonyms
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: Compile-time | Test Case:
crash or panic | polykinds/T13394
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Simon Peyton Jones
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: fixed | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash or panic | polykinds/T13394, T13394a Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * testcase: polykinds/T13394 => polykinds/T13394, T13394a * status: new => closed * resolution: => fixed Comment: OK, ''now'' it should be fixed. There was a second bug! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: highest | Milestone: 8.2.2 Component: Compiler | Version: 8.1 Resolution: fixed | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash or panic | polykinds/T13394, T13394a Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * milestone: 8.2.1 => 8.2.2 Comment: I've merged comment:5 to `ghc-8.2` with 704cbae29ee09431cfbd6b1566a6ec6856f125fc. This will be present in 8.2.2. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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