stg-lint fails on unlifted-type join point binding
While validating GHC with BuildFlavour=devel2
and -dstg-lint
I found that the linter chokes when it finds a join point of unlifted type (like this one from the Binary
module),
ghc-stage1: panic! (the 'impossible' happened)
(GHC version 8.3.20170815 for x86_64-unknown-linux):
*** Stg Lint ErrMsgs: in Stg2Stg ***
<no location info>: warning:
[RHS of $j_sDSL :: (# State# RealWorld, () #)]
Let(rec) binder ‘$j_sDSL’ has unlifted type ‘(# State# RealWorld,
() #)’
RHS: \r []
src<compiler/utils/Binary.hs:516:9-17>
src<compiler/utils/Binary.hs:(516,21)-(518,26)>
src<compiler/utils/Binary.hs:260:1-45>
src<compiler/utils/Binary.hs:(239,1)-(246,34)>
case readIntArray# [ww_sDSF 0# w1_sDSJ] of {
...
If I'm not mistaken there is no problem with join points having unlifted type (see Note [CoreSyn let/app invariant]
). We just need to update the STG linter appropriately.
Trac metadata
Trac field | Value |
---|---|
Version | 8.2.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |