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| author | Sebastian Graf <sebastian.graf@kit.edu> | 2018-10-14 20:32:40 +0200 |
|---|---|---|
| committer | Krzysztof Gogolewski <krz.gogolewski@gmail.com> | 2018-10-14 20:32:41 +0200 |
| commit | 448b77b93b369745e9bfbc8b46a5b87bb73dd379 (patch) | |
| tree | 8fd12e8698217f022651fe84a3ae9bf3d3e546a9 /compiler/codeGen | |
| parent | 68a747c702d2432cc90d2a79a6aba0e67ac3e2c0 (diff) | |
| download | haskell-448b77b93b369745e9bfbc8b46a5b87bb73dd379.tar.gz | |
Add RubbishLit for absent bindings of UnliftedRep
Summary:
Trac #9279 reminded us that the worker wrapper transformation copes
really badly with absent unlifted boxed bindings.
As `Note [Absent errors]` in WwLib.hs points out, we can't just use
`absentError` for unlifted bindings because there is no bottom to hide
the error in.
So instead, we synthesise a new `RubbishLit` of type
`forall (a :: TYPE 'UnliftedRep). a`, which code-gen may subsitute for
any boxed value. We choose `()`, so that there is a good chance that
the program crashes instead instead of leading to corrupt data, should
absence analysis have been too optimistic (#11126).
Reviewers: simonpj, hvr, goldfire, bgamari, simonmar
Reviewed By: simonpj
Subscribers: osa1, rwbarton, carter
GHC Trac Issues: #15627, #9279, #4306, #11126
Differential Revision: https://phabricator.haskell.org/D5153
Diffstat (limited to 'compiler/codeGen')
| -rw-r--r-- | compiler/codeGen/StgCmmUtils.hs | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/compiler/codeGen/StgCmmUtils.hs b/compiler/codeGen/StgCmmUtils.hs index 99fa550b83..94e19e47fd 100644 --- a/compiler/codeGen/StgCmmUtils.hs +++ b/compiler/codeGen/StgCmmUtils.hs @@ -105,6 +105,7 @@ mkSimpleLit _ (MachLabel fs ms fod) where -- TODO: Literal labels might not actually be in the current package... labelSrc = ForeignLabelInThisPackage +-- NB: RubbishLit should have been lowered in "CoreToStg" mkSimpleLit _ other = pprPanic "mkSimpleLit" (ppr other) -------------------------------------------------------------------------- |