December 2017 - ghc-tickets

[GHC] #14498: GHC internal error: "not in scope during TC but it passed the renamer"
by GHC 18 Dec '17

18 Dec '17

#14498: GHC internal error: "not in scope during TC but it passed the renamer" -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# Language PatternSynonyms, ViewPatterns, GADTs, ConstraintKinds, RankNTypes, KindSignatures, PolyKinds, ScopedTypeVariables, DataKinds #-} import Type.Reflection import Data.Kind data Dict c where Dict :: c => Dict c asTypeable :: TypeRep a -> Dict (Typeable a) asTypeable rep = withTypeable rep Dict pattern Typeable :: () => Typeable a => TypeRep a pattern Typeable <- (asTypeable -> Dict) where Typeable = typeRep data N = O | S N type SN = (TypeRep :: N -> Type) pattern SO = (Typeable :: TypeRep (O::N)) pattern SS :: forall (t :: k'). () => forall (a :: kk -> k') (n :: kk). (t ~ a n) => TypeRep n -> TypeRep t pattern SS n <- (App (Typeable :: TypeRep (a::kk -> k')) n) }}} fails with **GHC internal error** {{{ $ ghci -ignore-dot-ghci Bug.hs GHCi, version 8.3.20170920: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( Bug.hs, interpreted ) Bug.hs:31:47: error: • GHC internal error: ‘kk’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [a1Ao :-> Type variable ‘k'’ = k' :: *, a1Aq :-> Type variable ‘t’ = t :: k', a1Hs :-> Type variable ‘a’ = a :: k0, r1v4 :-> Identifier[asTypeable::forall k (a :: k). TypeRep a -> Dict (Typeable a), TopLevelLet]] • In the kind ‘kk -> k'’ In the first argument of ‘TypeRep’, namely ‘(a :: kk -> k')’ In the type ‘TypeRep (a :: kk -> k')’ | 31 | pattern SS n <- (App (Typeable :: TypeRep (a::kk -> k')) n) | ^^ Failed, 0 modules loaded. Prelude> }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14498> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14591: HEAD panic: tcSyntaxOp "noSyntaxExpr"
by GHC 18 Dec '17

18 Dec '17

#14591: HEAD panic: tcSyntaxOp "noSyntaxExpr" -------------------------------------+------------------------------------- Reporter: tianxiaogu | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Keywords: | Operating System: Linux Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following program triggers a bug in 8.2.2 and 8.5.20171215. {{{#!hs -- Checks that the ordering constraint on the groupWith function is respected {-# OPTIONS_GHC -XMonadComprehensions -XTransformListComp #-} module ShouldFail where import GHC.Exts (groupWith) data Unorderable = Gnorf | Pinky | Brain foo = [ () | Gnorf <- [Gnorf, Brain] , then group by x using groupWith ] }}} Reproduce: {{{ ghc bug.hs }}} Output: {{{ [1 of 1] Compiling ShouldFail ( bug.hs, bug.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.5.20171215 for x86_64-unknown-linux): tcSyntaxOp "noSyntaxExpr" Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable pprPanic, called at compiler/typecheck/TcExpr.hs:1436:31 in ghc:TcExpr Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug}}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14591> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14572: Document for writing GHC-based compiler
by GHC 18 Dec '17

18 Dec '17

#14572: Document for writing GHC-based compiler -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14572> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9244: Compiler could warn about type variable shadowing, and hint about ScopedTypeVariables
by GHC 18 Dec '17

18 Dec '17

#9244: Compiler could warn about type variable shadowing, and hint about ScopedTypeVariables -------------------------+------------------------------------------------- Reporter: | Owner: stusmith | Status: new Type: | Milestone: feature request | Version: 7.6.3 Priority: | Operating System: Unknown/Multiple normal | Type of failure: Incorrect warning at Component: | compile-time Compiler | Test Case: Keywords: | Blocking: Architecture: | Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- GHC already warns about variable shadowing: {{{ timesTwoPlusOne x = timesTwo x + 1 where timesTwo x = x * 2 Warning: This binding for `x' shadows the existing binding bound at <location> }}} However the similar warning doesn't happen for type variables. {{{ tryMaybe :: IO a -> IO (Maybe a) tryMaybe action = do result <- (try action) :: IO (Either SomeException a) return $ case result of Left _ -> Nothing Right v -> Just v Couldn't match type `a' with `a1' `a' is a rigid type variable bound by the type signature for tryMaybe :: IO a -> IO (Maybe a) at types.hs:<line>:13 `a1' is a rigid type variable bound by an expression type signature: IO (Either SomeException a1) at types.hs:<line>:15 Expected type: IO a1 Actual type: IO a ... }}} Here, I thought that the 'a' in the function's type declaration was the same 'a' in the expression type declaration. However in Haskell 98, they are completely different variables. Suggestion: if a type variable is renamed by the compiler due to a clash with another type variable, issue a warning that the second shadows the first, and give a hint about using -XScopedTypeVariables and forall. Alternative suggestion: if an error is displayed, where the error contains a renamed type variable, issue a hint that the second shadows the first, and give a hint about using -XScopedTypeVariables and forall. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9244> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14593: Allow deprecation notices for type and data constructors separately
by GHC 17 Dec '17

17 Dec '17

#14593: Allow deprecation notices for type and data constructors separately -------------------------------------+------------------------------------- Reporter: parsonsmatt | Owner: (none) Type: feature | Status: new request | Priority: low | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The [https://downloads.haskell.org/~ghc/8.2.2/docs/html/users_guide/glasgow_exts… #warning-and-deprecated-pragmas syntax for deprecations] only allows you to provide a single message for deprecations: > You can only attach to entities declared at top level in the module being compiled, and you can only use unqualified names in the list of entities. A capitalised name, such as T refers to either the type constructor T or the data constructor T, or both if both are in scope. If both are in scope, there is currently no way to specify one without the other (c.f. fixities Infix type constructors, classes, and type variables). It would be nice to provide separate messages in deprecations for type and data constructors. As an example, I am making a breaking change to a library, and I am providing deprecated shims for backwards-compatibility: {{{ -- Old: data SomeField rec where SomeField :: EntityField rec field -> SomeField rec -- New: data UpdateCollision rec where CopyField :: EntityField rec field -> UpdateCollision rec CopyUnless :: -- etc... type SomeField = UpdateCollision {-# DEPRECATED SomeField "The SomeField type was renamed to UpdateCollision." #-} pattern SomeField :: EntityField record typ -> SomeField record pattern SomeField x = CopyField x {-# DEPRECATED SomeField "The constructor SomeField is deprecated. Use the function copyField instead." #-} }}} The workaround is to provide a longer error message that combines the two. This is less pleasant than having separate notices, because it makes it less obvious for the client how to migrate. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14593> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14540: IndexError: pop from empty list
by GHC 16 Dec '17

16 Dec '17

#14540: IndexError: pop from empty list -------------------------------------+------------------------------------- Reporter: Lemming | Owner: hvr Type: bug | Status: new Priority: normal | Milestone: Component: Trac & Git | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- ==== How to Reproduce ==== While doing a GET operation on `/attachment/ticket/14539/`, Trac issued an internal error. ''(please provide additional details here)'' Request parameters: {{{ {u'action': u'new', 'path': u'14539/', 'realm': u'ticket'} }}} User agent: `#USER_AGENT#` ==== System Information ==== ''Systeminformation nicht verfügbar'' ==== Enabled Plugins ==== ''Plugininformation nicht verfügbar'' ==== Interface Customization ==== ''Interface customization information not available'' ==== Python Traceback ==== {{{ Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/trac/web/main.py", line 623, in _dispatch_request dispatcher.dispatch(req) File "/usr/local/lib/python2.7/dist-packages/trac/web/main.py", line 259, in dispatch iterable=chrome.use_chunked_encoding) File "/usr/local/lib/python2.7/dist-packages/trac/web/chrome.py", line 1165, in render_template encoding='utf-8') File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 184, in render return encode(generator, method=method, encoding=encoding, out=out) File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 58, in encode for chunk in iterator: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 350, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 829, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 669, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 774, in __call__ for kind, data, pos in chain(stream, [(None, None, None)]): File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 594, in __call__ for ev in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/trac/web/chrome.py", line 1432, in _strip_accesskeys for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/trac/web/chrome.py", line 1421, in _generate for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 706, in _unmark for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 1101, in __call__ for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 118, in __iter__ event = self.stream.next() File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 734, in __call__ for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 702, in _mark for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 378, in _match ctxt, start=idx + 1, **vars): File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 378, in _match ctxt, start=idx + 1, **vars): File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 362, in _match content = list(content) File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 326, in _match for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/path.py", line 588, in _generate subevent = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/path.py", line 588, in _generate subevent = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/filters/i18n.py", line 178, in _generate for event in msgbuf.translate(gettext(msgbuf.format())): File "/usr/local/lib/python2.7/dist-packages/genshi/filters/i18n.py", line 1051, in translate events = self.events[order].pop(0) IndexError: pop from empty list }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14540> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13627: IndexError: pop from empty list
by GHC 16 Dec '17

16 Dec '17

#13627: IndexError: pop from empty list -------------------------------------+------------------------------------- Reporter: Lemming | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- ==== How to Reproduce ==== While doing a GET operation on `/attachment/ticket/13626/`, Trac issued an internal error. ''(please provide additional details here)'' Request parameters: {{{ {u'action': u'new', 'path': u'13626/', 'realm': u'ticket'} }}} User agent: `#USER_AGENT#` ==== System Information ==== ''Systeminformation nicht verfügbar'' ==== Enabled Plugins ==== ''Plugininformation nicht verfügbar'' ==== Interface Customization ==== ''Interface customization information not available'' ==== Python Traceback ==== {{{ Traceback (most recent call last): File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 623, in _dispatch_request dispatcher.dispatch(req) File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 259, in dispatch iterable=chrome.use_chunked_encoding) File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 1164, in render_template encoding='utf-8') File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 184, in render return encode(generator, method=method, encoding=encoding, out=out) File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 58, in encode for chunk in iterator: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 350, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 829, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 669, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 774, in __call__ for kind, data, pos in chain(stream, [(None, None, None)]): File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 594, in __call__ for ev in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 1431, in _strip_accesskeys for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 1420, in _generate for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 706, in _unmark for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 1101, in __call__ for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 118, in __iter__ event = self.stream.next() File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 734, in __call__ for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 702, in _mark for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 378, in _match ctxt, start=idx + 1, **vars): File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 378, in _match ctxt, start=idx + 1, **vars): File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 362, in _match content = list(content) File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 326, in _match for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/path.py", line 588, in _generate subevent = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/path.py", line 588, in _generate subevent = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/filters/i18n.py", line 178, in _generate for event in msgbuf.translate(gettext(msgbuf.format())): File "/usr/local/lib/python2.7/dist-packages/genshi/filters/i18n.py", line 1051, in translate events = self.events[order].pop(0) IndexError: pop from empty list }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13627> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13418: IndexError: pop from empty list
by GHC 16 Dec '17

16 Dec '17

#13418: IndexError: pop from empty list -------------------------------------+------------------------------------- Reporter: ralf | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- ==== How to Reproduce ==== While doing a GET operation on `/attachment/ticket/13417/`, Trac issued an internal error. ''(please provide additional details here)'' Request parameters: {{{ {u'action': u'new', 'path': u'13417/', 'realm': u'ticket'} }}} User agent: `Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.76 Safari/537.36` ==== System Information ==== ''Systeminformation nicht verfügbar'' ==== Enabled Plugins ==== ''Plugininformation nicht verfügbar'' ==== Interface Customization ==== ''Interface customization information not available'' ==== Python Traceback ==== {{{ Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/trac/web/main.py", line 613, in _dispatch_request dispatcher.dispatch(req) File "/usr/local/lib/python2.7/dist-packages/trac/web/main.py", line 273, in dispatch iterable=chrome.use_chunked_encoding) File "/usr/local/lib/python2.7/dist-packages/trac/web/chrome.py", line 1159, in render_template encoding='utf-8') File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 184, in render return encode(generator, method=method, encoding=encoding, out=out) File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 58, in encode for chunk in iterator: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 350, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 829, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 669, in __call__ for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 774, in __call__ for kind, data, pos in chain(stream, [(None, None, None)]): File "/usr/local/lib/python2.7/dist-packages/genshi/output.py", line 594, in __call__ for ev in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/trac/web/chrome.py", line 1426, in _strip_accesskeys for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/trac/web/chrome.py", line 1415, in _generate for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 706, in _unmark for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 1101, in __call__ for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 118, in __iter__ event = self.stream.next() File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 734, in __call__ for mark, event in stream: File "/usr/local/lib/python2.7/dist- packages/genshi/filters/transform.py", line 702, in _mark for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 378, in _match ctxt, start=idx + 1, **vars): File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 378, in _match ctxt, start=idx + 1, **vars): File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 362, in _match content = list(content) File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 326, in _match for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/path.py", line 588, in _generate subevent = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/core.py", line 289, in _ensure for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/path.py", line 588, in _generate subevent = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 618, in _include for event in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/template/markup.py", line 315, in _strip event = next() File "/usr/local/lib/python2.7/dist-packages/genshi/template/base.py", line 558, in _flatten for kind, data, pos in stream: File "/usr/local/lib/python2.7/dist-packages/genshi/filters/i18n.py", line 178, in _generate for event in msgbuf.translate(gettext(msgbuf.format())): File "/usr/local/lib/python2.7/dist-packages/genshi/filters/i18n.py", line 1051, in translate events = self.events[order].pop(0) IndexError: pop from empty list }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13418> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8272: testing if SpLim=$rbp and Sp=$rsp changed performance at all
by GHC 15 Dec '17

15 Dec '17

#8272: testing if SpLim=$rbp and Sp=$rsp changed performance at all ----------------------------------------------+---------------------------- Reporter: carter | Owner: carter Type: task | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.7 Keywords: callingConvention | Operating System: Architecture: x86_64 (amd64) | Unknown/Multiple Difficulty: Project (more than a week) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: ----------------------------------------------+---------------------------- testing if SpLim=$rbp and Sp=$rsp changed performance at all would need a stack check but then push could be used to spill to the stack Idea via Nathan Howell. At the very least, the x86 PUSH instruction has a more succinct encoding than MOV. worth hacking out to see if this can measurable shift ghc perf on nofib or not. this would be part of a larger effort to explore ways to improve GHC's calling convention for modern hardware -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8272> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14587: Unidirectional pattern signatures do not need to be invariant w.r.t. higher-rank polymorphism
by GHC 15 Dec '17

15 Dec '17

#14587: Unidirectional pattern signatures do not need to be invariant w.r.t. higher-rank polymorphism -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Best explained by example: {{{#!hs data T = MkT (forall a. a -> a) pattern PT :: (Int -> Int) -> T pattern PT x <- MkT x }}} This looks perfectly reasonable to me. And the hand-written matcher is also accepted. Note that a similar bidirectional pattern synonym should indeed be rejected. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14587> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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