#11176: Typechecked AST for recursive top-level call refers to non-exported HsVar.
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Reporter: literon | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.10.2
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:
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Code:
{{{#!hs
module B where
aaa x = aaa x
bbb = aaa 1
}}}
=== In the renamed AST
The reference is to the exported aaa (span 3:1-3, sort WiredIn), which is
as expected (by me at least).
(dump with ghc-dump-tree with some local mods compiled by GHC 7.10.2)
{{{
(HsApp
(L /tmp/B.hs:3:9-11
(HsVar
here ------------> { n_loc = /tmp/B.hs:3:1-3
<----------- here
, n_sort = {
WiredIn = Module main B }
, VarName = aaa
}))
(L /tmp/B.hs:3:13
(HsVar
{ n_loc =
/tmp/B.hs:3:5
, n_sort = Internal
, VarName = x
})))))
}}}
=== In the typechecked AST
Here the call target changes to internal (as described by the monomorphic
binding abe_mono).
{{{
(HsApp
(L /tmp/B.hs:3:9-11
(HsVar
{ varType =
{ t -> t =
FunTy
(TyVarTy
{
varType =
{ * = TyConApp * [] }
,
n_loc = /tmp/B.hs:3:1-13
,
n_sort = Internal
,
TvName = t
})
(TyVarTy
{
varType =
{ * = TyConApp * [] }
,
n_loc = /tmp/B.hs:3:1-13
,
n_sort = Internal
,
TvName = t
})
}
here -------------> , n_loc = /tmp/B.hs:3:1-13
, n_sort = Internal
, VarName = aaa
}))
(L /tmp/B.hs:3:13
(HsVar
{ varType =
{ t =
TyVarTy
{
varType =
{
* = TyConApp * [] }
, n_loc
= /tmp/B.hs:3:1-13
,
n_sort = Internal
,
TvName = t
}
}
, n_loc =
/tmp/B.hs:3:5
, n_sort = Internal
, VarName = x
})))))
}}}
(Just remarking, that GHC 7.8 and 7.10 seem to have improved the span
ranges a bit over 7.6, so trying to reproduce with 7.6 the span will be
the shorter one on the function name, but the sort will still be the
internal).
Note that referring the function in a non-recursive way seem to refer to
the exported (abe_poly) binding.
From the perspective of a tooling writer, this difference is somewhat
surprising, and is a case to be handled separately.
* Is there a fundamental reason why the reference changes after
Typechecking?
* Since I'm not deeply familiar with the AST, I might miss something.
Does it happen in other cases too that sometimes abe_poly is referred,
sometimes the abe_mono? If so, what is the rule?
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11176>
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