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| author | Simon Marlow <marlowsd@gmail.com> | 2014-07-31 11:47:16 +0100 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2014-08-01 12:45:41 +0100 |
| commit | 2989ffdcb88ab24e8a4e8b3d0454497a0db2652c (patch) | |
| tree | 56f3ba6c42c1d4268c729c0becc4971f7c2dee1f /compiler/cmm/CmmBuildInfoTables.hs | |
| parent | 6c06db13a670f156a79301c89b6bf2669d91af88 (diff) | |
| download | haskell-2989ffdcb88ab24e8a4e8b3d0454497a0db2652c.tar.gz | |
A panic in CmmBuildInfoTables.bundle shouldn't be a panic (#9329)
Summary:
This code needs more comments, but I believe this is safe. By
definition I can't have broken anything that was working by turning a
panic into a non-panic anyway.
Test Plan: validate
Reviewers: hvr, simonpj, austin
Subscribers: simonmar, relrod, ezyang, carter
Differential Revision: https://phabricator.haskell.org/D105
GHC Trac Issues: #9329
Diffstat (limited to 'compiler/cmm/CmmBuildInfoTables.hs')
| -rw-r--r-- | compiler/cmm/CmmBuildInfoTables.hs | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/compiler/cmm/CmmBuildInfoTables.hs b/compiler/cmm/CmmBuildInfoTables.hs index e10716a2ac..6521a84006 100644 --- a/compiler/cmm/CmmBuildInfoTables.hs +++ b/compiler/cmm/CmmBuildInfoTables.hs @@ -286,7 +286,7 @@ bundle :: Map CLabel CAFSet -> (CAFEnv, CmmDecl) -> (CAFSet, Maybe CLabel) -> (BlockEnv CAFSet, CmmDecl) -bundle flatmap (env, decl@(CmmProc infos lbl _ g)) (closure_cafs, mb_lbl) +bundle flatmap (env, decl@(CmmProc infos _lbl _ g)) (closure_cafs, mb_lbl) = ( mapMapWithKey get_cafs (info_tbls infos), decl ) where entry = g_entry g @@ -297,9 +297,13 @@ bundle flatmap (env, decl@(CmmProc infos lbl _ g)) (closure_cafs, mb_lbl) get_cafs l _ | l == entry = entry_cafs - | otherwise = if not (mapMember l env) - then pprPanic "bundle" (ppr l <+> ppr lbl <+> ppr (info_tbls infos) $$ ppr env $$ ppr decl) - else flatten flatmap $ expectJust "bundle" $ mapLookup l env + | Just info <- mapLookup l env = flatten flatmap info + | otherwise = Set.empty + -- the label might not be in the env if the code corresponding to + -- this info table was optimised away (perhaps because it was + -- unreachable). In this case it doesn't matter what SRT we + -- infer, since the info table will not appear in the generated + -- code. See #9329. bundle _flatmap (_, decl) _ = ( mapEmpty, decl ) |