- ghc-commits - Haskell.org

[Git][ghc/ghc][wip/clc-proposal-442] 3 commits: Update expected error message in testcase T25180
by BinderDavid (＠BinderDavid) 23 Sep '26

23 Sep '26

BinderDavid pushed to branch wip/clc-proposal-442 at Glasgow Haskell Compiler / GHC Commits: 8801a723 by David Binder at 2026-09-23T13:42:21+01:00 Update expected error message in testcase T25180 The testcase T25180 checks for the error messages when the file is compiled with the options: '-fdefer-type-errors -fno-max-valid-hole-fits' - - - - - 240fa032 by David Binder at 2026-09-23T14:00:21+01:00 Fix expected output in testsuite of haddock - - - - - e2b8ee4b by David Binder at 2026-09-23T14:17:20+01:00 Add entry to changelog.d - - - - - 4 changed files: - + changelog.d/clc-442 - testsuite/tests/typecheck/should_compile/T25180.stderr - utils/haddock/html-test/ref/Bug923.html - utils/haddock/html-test/ref/Instances.html Changes: ===================================== changelog.d/clc-442 ===================================== @@ -0,0 +1,8 @@ +section: base +mrs: !16718 +synopsis: + Expose `data Unit` and `data TupleN` from `Data.Tuple` in `base` +description: + The data types `data Unit` and `data TupleN` (for N from 2 to 64) are now exported from + `Data.Tuple` in the `base` library instead of `Data.Tuple.Experimental` in `ghc-experimental`. + See `CLC proposal 442 <https://github.com/haskell/core-libraries-committee/issues/442>`_. ===================================== testsuite/tests/typecheck/should_compile/T25180.stderr ===================================== @@ -5,6 +5,9 @@ T25180.hs:12:8: warning: [GHC-88464] [-Wtyped-holes (in -Wdefault)] Valid hole fits include tup0 :: () (bound at T25180.hs:12:1) () :: () (bound at <wired into compiler>) + () :: () + (imported from ‘Data.Tuple’ at T25180.hs:6:1-17 + (and originally defined in ‘GHC.Internal.Tuple’)) mempty :: forall a. Monoid a => a with mempty @() (imported from ‘Prelude’ @@ -60,6 +63,10 @@ T25180.hs:26:8: warning: [GHC-88464] [-Wtyped-holes (in -Wdefault)] (,) :: forall a b. a -> b -> (a, b) with (,) @a @b (bound at <wired into compiler>) + (,) :: forall a b. a -> b -> (a, b) + with (,) @a @b + (imported from ‘Data.Tuple’ at T25180.hs:6:1-17 + (and originally defined in ‘GHC.Internal.Tuple’)) T25180.hs:33:8: warning: [GHC-88464] [-Wtyped-holes (in -Wdefault)] • Found hole: _ :: a -> b -> c -> (a, b, c) @@ -75,6 +82,10 @@ T25180.hs:33:8: warning: [GHC-88464] [-Wtyped-holes (in -Wdefault)] (,,) :: forall a b c. a -> b -> c -> (a, b, c) with (,,) @a @b @c (bound at <wired into compiler>) + (,,) :: forall a b c. a -> b -> c -> (a, b, c) + with (,,) @a @b @c + (imported from ‘Data.Tuple’ at T25180.hs:6:1-17 + (and originally defined in ‘GHC.Internal.Tuple’)) T25180.hs:38:11: warning: [GHC-88464] [-Wtyped-holes (in -Wdefault)] • Found hole: _ :: (# #) ===================================== utils/haddock/html-test/ref/Bug923.html ===================================== @@ -76,7 +76,9 @@ >forall a. a -> <a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a @@ -126,7 +128,9 @@ >forall a. a -> <a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a @@ -156,7 +160,9 @@ >Eq</a > (<a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a @@ -188,7 +194,9 @@ >(==)</a > :: <a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a @@ -196,7 +204,9 @@ >Type</a >)) -> <a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a @@ -212,7 +222,9 @@ >(/=)</a > :: <a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a @@ -220,7 +232,9 @@ >Type</a >)) -> <a href="#" title="Bug923" >T</a - > ('(,) a :: <a href="#" title="Data.Kind" + > ('<a href="#" title="Data.Tuple" + >(,)</a + > a :: <a href="#" title="Data.Kind" >Type</a > -> (<a href="#" title="Data.Kind" >Type</a ===================================== utils/haddock/html-test/ref/Instances.html ===================================== @@ -450,7 +450,9 @@ >) => <a href="#" title="Instances" >Foo</a - > ((,) (f a)) (<a href="#" title="Data.Tuple" + >(,)</a + > (f a)) <a href="#" class="selflink" >#</a ></td @@ -560,7 +562,9 @@ > <a href="#" title="Instances" >Foo</a - > ((,,) a a) (<a href="#" title="Data.Tuple" + >(,,)</a + > a a) <a href="#" class="selflink" >#</a ></td @@ -1164,9 +1168,13 @@ > <a href="#" title="Instances" >Foo</a - > ((,,) a b) => <a href="#" title="Instances" + > (<a href="#" title="Data.Tuple" + >(,,)</a + > a b) => <a href="#" title="Instances" >Bar</a - > ((,,) a b) (a, b, a) (<a href="#" title="Data.Tuple" + >(,,)</a + > a b) (a, b, a) <a href="#" class="selflink" >#</a ></td View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0957bd7e5c7bb455716cd646725ab5… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0957bd7e5c7bb455716cd646725ab5… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][wip/apk/tag-strict-bot] Fix a few tag inference bugs.
by Andreas Klebinger (＠AndreasK) 23 Sep '26

23 Sep '26

Andreas Klebinger pushed to branch wip/apk/tag-strict-bot at Glasgow Haskell Compiler / GHC Commits: ec64d9d2 by Andreas Klebinger at 2026-09-23T12:10:43+00:00 Fix a few tag inference bugs. * Treat bottoming functions and nullary join points as functions. * When generating bytecode don't rely on imported tag sigs. Fixes #27831, #27841 and #27842. - - - - - 21 changed files: - + changelog.d/T27831-bottoming-strict-field - + changelog.d/T27842-bytecode-imported-tags - compiler/GHC/Stg/EnforceEpt.hs - compiler/GHC/Stg/EnforceEpt/Rewrite.hs - compiler/GHC/Stg/EnforceEpt/Types.hs - + testsuite/tests/bytecode/T27842.hs - + testsuite/tests/bytecode/T27842.stdout - + testsuite/tests/bytecode/T27842A.hs - + testsuite/tests/bytecode/T27842N.hs - testsuite/tests/bytecode/all.T - testsuite/tests/simplStg/should_compile/all.T - + testsuite/tests/simplStg/should_compile/inferTags005.hs - + testsuite/tests/simplStg/should_compile/inferTags005.stderr - + testsuite/tests/simplStg/should_compile/inferTags006.hs - + testsuite/tests/simplStg/should_compile/inferTags006.stderr - + testsuite/tests/simplStg/should_run/InferTags007_A.hs - + testsuite/tests/simplStg/should_run/T27831.hs - + testsuite/tests/simplStg/should_run/T27831.stdout - testsuite/tests/simplStg/should_run/all.T - + testsuite/tests/simplStg/should_run/inferTags007.hs - + testsuite/tests/simplStg/should_run/inferTags007.stdout Changes: ===================================== changelog.d/T27831-bottoming-strict-field ===================================== @@ -0,0 +1,8 @@ +section: compiler +issues: #27831 +mrs: !16719 +synopsis: + Fix a segfault that could occur when a bottoming function was stored in a strict field. +description: + This was happening when a function that always diverges (e.g. ``\_ -> error "..."``) was stored in a strict field, and the constructor was pattern matched on + in "nearby" code where the structure of the constructor application was still visible to GHC. ===================================== changelog.d/T27842-bytecode-imported-tags ===================================== @@ -0,0 +1,6 @@ +section: bytecode +issues: #27842 +mrs: !16719 +synopsis: + Fix a segfault caused by reusing interface files generated with + ``-fbyte-code-and-object-code`` for interpreter sessions using ``-fprefer-byte-code``. ===================================== compiler/GHC/Stg/EnforceEpt.hs ===================================== @@ -334,9 +334,15 @@ a) Tags for let-bindings: b) When referencing ids from other modules the Cmm backend will try to put a proper tag on these references through various means. When doing analysis we usually predict these cases to improve precision of the analysis. - But to my knowledge the bytecode generator makes no such attempts so we must - not infer imported bindings as tagged. - This is handled in GHC.Stg.EnforceEpt.Types.lookupInfo + The bytecode generator gives fewer guarantees about what it tags. + So we simply assume it fails to tag binders, even in the cases where it does. + + This is handled in GHC.Stg.EnforceEpt.Types.argTagInfo + + Eventually we will want to update the Analysis and bco code gen to uphold and + take advantage of tag inference at least to some degree. But for now it's + not a perf benefit for interpreted code, and essentially only run to uphold + the "strict field invariant"/EPT Invariant described in EPT enforcement. -} @@ -359,7 +365,7 @@ enforceEpt ppr_opts !for_bytecode logger this_mod stg_binds = do -- Rewrite STG to uphold the strict field invariant us_t <- mkSplitUniqSupply StgTag - let rewritten_binds = {-# SCC "StgEptRewrite" #-} rewriteTopBinds this_mod us_t stg_binds_w_tags :: [TgStgTopBinding] + let rewritten_binds = {-# SCC "StgEptRewrite" #-} rewriteTopBinds for_bytecode this_mod us_t stg_binds_w_tags :: [TgStgTopBinding] return (rewritten_binds,export_tag_info) @@ -414,12 +420,14 @@ inferTagExpr env (StgApp fun args) | isDeadEndAppSig (idDmdSig fun) (length args) = TagBottoming - | fun_arity == 0 -- Unknown arity => Thunk or unknown call + | not (isJoinId fun) -- zero arity join ids behave like functions. + , fun_arity == 0 -- Unknown arity => Thunk or unknown call = TagDunno -- Imported function with known return tag | Just (TagFun res_info) <- tagSigInfo (idInfo fun) , fun_arity == length args -- Saturated + , not (te_bytecode env) -- #27842 = res_info -- Local function with known return tag @@ -613,8 +621,8 @@ it safely any tag sig we like. So we give it TagBottoming, as it allows the combined tag sig of the case expression to be the combination of all non-bottoming branches. -NB: After the analysis is done we go back to treating bottoming functions as -untagged to ensure they are evaluated as expected in code like: +NB: We now distinguish functions from values. Allowing us to treat bottom functions +as tagged, while still doing the right thing for bottom values in code like: case bottom_id of { ...} ===================================== compiler/GHC/Stg/EnforceEpt/Rewrite.hs ===================================== @@ -13,7 +13,7 @@ import GHC.Builtin.PrimOps ( PrimOp(..) ) import GHC.Types.Basic ( CbvMark (..), isMarkedCbv , TopLevelFlag(..), isTopLevel ) import GHC.Types.Id -import GHC.Types.Name +import GHC.Types.Name ( nameIsLocalOrFrom ) import GHC.Types.Unique.Supply import GHC.Types.Unique.FM import GHC.Types.RepType @@ -22,10 +22,7 @@ import GHC.Unit.Types import GHC.Core.DataCon import GHC.Core ( AltCon(..) ) -import GHC.Core.Type - -import GHC.StgToCmm.Types -import GHC.StgToCmm.Closure (importedIdLFInfo) +import GHC.Core.Type ( definitelyLiftedType ) import GHC.Stg.Utils import GHC.Stg.Syntax as StgSyn @@ -41,7 +38,7 @@ import GHC.Stg.EnforceEpt.Types import Control.Monad -newtype RM a = RM { unRM :: (State (UniqFM Id TagSig, UniqSupply, Module, IdSet) a) } +newtype RM a = RM { unRM :: (State (UniqFM Id TagSig, UniqSupply, Module, IdSet, Bool) a) } deriving (Functor, Monad, Applicative) ------------------------------------------------------------ @@ -108,29 +105,34 @@ when building the free variable list. instance MonadUnique RM where getUniqueSupplyM = RM $ do - (m, us, mod,lcls) <- get + (m, us, mod,lcls,for_bytecode) <- get let (us1, us2) = splitUniqSupply us - (put) (m,us2,mod,lcls) + (put) (m,us2,mod,lcls,for_bytecode) return us1 getMap :: RM (UniqFM Id TagSig) -getMap = RM $ ((\(fst,_,_,_) -> fst) <$> get) +getMap = RM $ ((\(fst,_,_,_,_) -> fst) <$> get) setMap :: (UniqFM Id TagSig) -> RM () setMap !m = RM $ do - (_,us,mod,lcls) <- get - put (m, us,mod,lcls) - -getMod :: RM Module -getMod = RM $ ( (\(_,_,thrd,_) -> thrd) <$> get) + (_,us,mod,lcls,for_bytecode) <- get + put (m, us,mod,lcls,for_bytecode) getFVs :: RM IdSet -getFVs = RM $ ((\(_,_,_,lcls) -> lcls) <$> get) +getFVs = RM $ ((\(_,_,_,lcls,_) -> lcls) <$> get) setFVs :: IdSet -> RM () setFVs !fvs = RM $ do - (tag_map,us,mod,_lcls) <- get - put (tag_map, us,mod,fvs) + (tag_map,us,mod,_lcls,for_bytecode) <- get + put (tag_map, us,mod,fvs,for_bytecode) + +getMod :: RM Module +getMod = RM $ ( (\(_,_,c,_,_) -> c) <$> get) + +-- | Are we generating bytecode? Must agree with the flag the analysis ran +-- with, so both sides make the same tagging decisions. +getForBytecode :: RM Bool +getForBytecode = RM $ ((\(_,_,_,_,for_bytecode) -> for_bytecode) <$> get) -- Rewrite the RHS(s) while making the id and it's sig available -- to determine if things are tagged/need to be captured as FV. @@ -238,51 +240,26 @@ indicates a bug in the tag inference implementation. For this reason we assert that we are running in interactive mode if a lookup fails. -} isTagged :: Id -> RM Bool -isTagged v - -- See Note [Bottom functions are TagBottoming] - | isDeadEndId v = pure False - | otherwise = do +isTagged v = do + for_bytecode <- getForBytecode this_mod <- getMod - -- See Note [Tag inference for interactive contexts] - let lookupDefault v = assertPpr (isInteractiveModule this_mod) - (text "unknown Id:" <> ppr this_mod <+> ppr v) - (TagVal TagDunno) - case nameIsLocalOrFrom this_mod (idName v) of - True - | definitelyUnliftedType (idType v) - -- NB: v might be the Id of a representation-polymorphic join point, - -- so we shouldn't use isUnliftedType here. See T22212. - -> return True - | otherwise -> do -- Local binding - !s <- getMap - let !sig = lookupWithDefaultUFM s (lookupDefault v) v - return $ case sig of - TagFun _ -> True -- function closure is tagged - TagVal TagDunno -> False - TagVal TagEPT -> True - TagVal TagBottoming -> True - TagVal (TagTuple _) -> True -- Consider unboxed tuples tagged. - -- Imported - False -> return $! - -- Determine whether it is tagged from the LFInfo of the imported id. - -- See Note [The LFInfo of Imported Ids] - case importedIdLFInfo v of - -- Function, applied not entered. - LFReEntrant {} - -> True - -- Thunks need to be entered. - LFThunk {} - -> False - -- LFCon means we already know the tag, and it's tagged. - LFCon {} - -> True - LFUnknown {} - -> False - LFUnlifted {} -- Unboxed, tagging irrelevant - -> True - LFLetNoEscape {} - -- Shouldn't be possible. I don't think we can export letNoEscapes - -> True + s <- getMap + let get_env_sig = lookupUFM s + massertPpr + -- Assert the env is complete for local lifted binders, which means either + -- - The binder is present in the env + -- - The binder is not a local lifted binder or comes from a ghci context + (isJust (get_env_sig v) + -- See Note [Tag inference for interactive contexts] + || isInteractiveModule this_mod + || not (nameIsLocalOrFrom this_mod (idName v)) + || not (definitelyLiftedType (idType v))) + (text "unknown Id:" <> ppr this_mod <+> ppr v) + -- TODO: We could refactor the whole pass such that we also set id_tagSig + -- for every imported id. But this likely comes with a heavy allocation + -- overhead so for now we just ensure to use the same logic across analysis + -- and rewriter. + pure $! isTaggedInfo $ argTagInfo for_bytecode (get_env_sig v) (StgVarArg v) isArgTagged :: StgArg -> RM Bool @@ -299,11 +276,12 @@ mkLocalArgId id = do --------------------------- -rewriteTopBinds :: Module -> UniqSupply -> [GenStgTopBinding 'InferTaggedBinders] -> [TgStgTopBinding] -rewriteTopBinds mod us binds = +rewriteTopBinds :: Bool -- ^ Generating bytecode? + -> Module -> UniqSupply -> [GenStgTopBinding 'InferTaggedBinders] -> [TgStgTopBinding] +rewriteTopBinds for_bytecode mod us binds = let doBinds = mapM rewriteTop binds - in evalState (unRM doBinds) (mempty, us, mod, mempty) + in evalState (unRM doBinds) (mempty, us, mod, mempty, for_bytecode) rewriteTop :: InferStgTopBinding -> RM TgStgTopBinding rewriteTop (StgTopStringLit v s) = return $! (StgTopStringLit v s) ===================================== compiler/GHC/Stg/EnforceEpt/Types.hs ===================================== @@ -12,7 +12,7 @@ where import GHC.Prelude import GHC.Core.DataCon -import GHC.Core.Type (isUnliftedType) +import GHC.Core.Type (isUnliftedType, definitelyUnliftedType) import GHC.Types.Id import GHC.Stg.Syntax import GHC.Stg.EnforceEpt.TagSig as TagSig @@ -22,6 +22,7 @@ import GHC.Utils.Misc( zipWithEqual ) import GHC.Utils.Panic import GHC.StgToCmm.Types +import GHC.StgToCmm.Closure (importedIdLFInfo) {- ********************************************************************* * * @@ -97,31 +98,37 @@ lookupReturnInfo env fun = case lookupVarEnv (te_env env) fun of Just (TagVal _) -> Nothing Nothing -> Nothing --- | Look up a value-level tag for an argument: either from the env (where --- a function-typed argument flattens to TagEPT — its closure is tagged) --- or derived from information on the variable itself. -lookupInfo :: TagEnv p -> StgArg -> TagInfo -lookupInfo env (StgVarArg var) +{-# INLINE argTagInfo #-} -- Specialize for the call site. +-- | Look up a value-level tag. +-- +-- If we can do so faster avoid inspecting the env and compute the info from the Id. +-- If we can't check the provided env value or fall back to safe defaults. +argTagInfo :: Bool -> (Maybe TagSig) -> StgArg -> TagInfo +argTagInfo _for_bytecode _env_sig (StgLitArg{}) = TagEPT +argTagInfo for_bytecode env_sig (StgVarArg var) -- Nullary data constructors like True, False | Just dc <- isDataConWorkId_maybe var , isNullaryRepDataCon dc , not for_bytecode = TagEPT - | isUnliftedType (idType var) + -- NB: v might be the Id of a representation-polymorphic join point, + -- so we shouldn't use isUnliftedType here. See T22212. + | definitelyUnliftedType (idType var) = TagEPT -- Variables in the environment. A function binding flattens to TagEPT -- since a function closure pointer is properly tagged; its return info -- is not relevant when the function is used as a value. - | Just sig <- lookupVarEnv (te_env env) var + | Just sig <- env_sig = case sig of TagVal info -> info TagFun _ -> TagEPT - | Just lf_info <- idLFInfo_maybe var - , not for_bytecode - = case lf_info of + | lf_info <- importedIdLFInfo var -- will make up LFInfo if not present. + = if for_bytecode then TagDunno + else + case lf_info of -- Function, tagged (with arity) LFReEntrant {} -> TagEPT @@ -138,13 +145,14 @@ lookupInfo env (StgVarArg var) -- Shouldn't be possible. I don't think we can export letNoEscapes LFLetNoEscape {} -> panic "LFLetNoEscape exported" - | otherwise - = TagDunno - where - for_bytecode = te_bytecode env - -lookupInfo _ (StgLitArg {}) - = TagEPT +-- | Look up a value-level tag for an argument: either from the env (where +-- a function-typed argument flattens to TagEPT — its closure is tagged) +-- or derived from information on the variable itself. +lookupInfo :: TagEnv p -> StgArg -> TagInfo +lookupInfo env arg@(StgVarArg var) = + let env_sig = (lookupVarEnv (te_env env) var) + in argTagInfo (te_bytecode env) env_sig arg +lookupInfo _env (StgLitArg{}) = TagEPT isDunnoSig :: TagSig -> Bool isDunnoSig (TagVal TagDunno) = True ===================================== testsuite/tests/bytecode/T27842.hs ===================================== @@ -0,0 +1,42 @@ +{-# LANGUAGE UnboxedTuples #-} +{-# OPTIONS_GHC -fno-worker-wrapper -fno-cpr-anal #-} +-- Regression test for #27842. +-- +-- The basic rundown is this: +-- We produce one interface file, however we store information dependent on the +-- code generation method in the interface file. +-- +-- We happen to pick the native code information to store in the interface file. +-- +-- When we compile a module M this way, and then generate byte code for code +-- depending on M based on M.hi we will assume certain exported definitions are EPT +-- tagged, despite the interpreter doing no such thing. +-- +-- This then led to crashes in the interpreter. +-- +-- We test three kinds of imported definitions: +-- * mk uses fun, a function whose TagSig says its result is tagged. +-- * bar uses just_con, a value whose LFInfo says it is a constructor. +-- * baz uses gt_con, the same for a nullary constructor. +module Main where + +import T27842A (fun, just_con, gt_con) +import T27842N (S(..), use_S, M(..), use_M, N(..), use_N) + +mk :: Int -> S +mk x = case fun x of (# xs, _ #) -> S xs +{-# NOINLINE mk #-} + +bar :: M +bar = M just_con +{-# NOINLINE bar #-} + +baz :: N +baz = N gt_con +{-# NOINLINE baz #-} + +main :: IO () +main = do + print (use_S (mk 42)) + print (use_M bar) + print (use_N baz) ===================================== testsuite/tests/bytecode/T27842.stdout ===================================== @@ -0,0 +1,3 @@ +42 +42 +3 ===================================== testsuite/tests/bytecode/T27842A.hs ===================================== @@ -0,0 +1,19 @@ +{-# LANGUAGE UnboxedTuples #-} +{-# OPTIONS_GHC -fno-worker-wrapper -fno-cpr-anal #-} +module T27842A (fun, just_con, gt_con) where + +-- The native EPT run gives fun the TagSig TagFun[TagTuple[TagEPT, TagDunno]]: +fun :: Int -> (# [Int], Int #) +fun x = let xs = x : xs in (# xs, x #) +{-# NOINLINE fun #-} + +-- In native code a static constructor, in bytecode an unevaluated closure. +just_con :: Maybe Int +just_con = Just 42 +{-# NOINLINE just_con #-} + +-- The same for a nullary constructor. Without its pointer tag, the object code +-- in T27842N would take the LT alternative, so GT shows the difference. +gt_con :: Ordering +gt_con = GT +{-# NOINLINE gt_con #-} ===================================== testsuite/tests/bytecode/T27842N.hs ===================================== @@ -0,0 +1,26 @@ +{-# OPTIONS_GHC -fno-byte-code-and-object-code #-} +-- We compile this module as native code, depending on A's interface file. +-- A itself is loaded into GHCi, despite it's interface file being generated based +-- on native code generation. +module T27842N (S(..), use_S, M(..), use_M, N(..), use_N) where + +data S = S ![Int] + +-- We take apart the strict constructor value and branch on the value in its field. +-- If the field content is not EPT this causes undefined behaviour. + +use_S :: S -> Int +use_S (S xs) = case xs of { (y:_) -> y; [] -> -1 } +{-# NOINLINE use_S #-} + +data M = M !(Maybe Int) + +use_M :: M -> Int +use_M (M m) = case m of { Just x -> x; Nothing -> -1 } +{-# NOINLINE use_M #-} + +data N = N !Ordering + +use_N :: N -> Int +use_N (N o) = case o of { LT -> 1; EQ -> 2; GT -> 3 } +{-# NOINLINE use_N #-} ===================================== testsuite/tests/bytecode/all.T ===================================== @@ -17,3 +17,12 @@ test('T26216', extra_files(["T26216_aux.hs"]), ghci_script, ['T26216.script']) test('T27001', [extra_files(['T27001.hs']), req_interp], run_command, ['{compiler} -e main -O -fno-unoptimized-core-for-interpreter T27001.hs']) + +# Bytecode must not trust tag information from imported interfaces, which +# comes from native code (#27842): neither the TagSig of an imported function +# nor the LFInfo of an imported value (with and without constructor fields). +test('T27842', [extra_files(['T27842A.hs', 'T27842N.hs']), req_interp], + run_command, + ['{compiler} -e main -O -fno-unoptimized-core-for-interpreter ' + '-fobject-code -fbyte-code-and-object-code -fwrite-byte-code -fprefer-byte-code ' + 'T27842.hs']) ===================================== testsuite/tests/simplStg/should_compile/all.T ===================================== @@ -25,5 +25,17 @@ test('inferTags003', [ only_ways(['optasm']), ], compile, ['-ddump-cmm -dno-typeable-binds -O']) test('inferTags004', normal, compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) test('T27005b', normal, compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) +# Both f and the join point j should have a signature TagTuple[TagEPT, TagEPT] +test('inferTags005', + grep_errmsg(r'(TagTuple\[TagEPT, TagEPT\])', [1]), + compile, + ['-O -fno-worker-wrapper -fno-cpr-anal -ddump-stg-tags ' + '-dno-typeable-binds -dsuppress-uniques']) +# The function needs to have a signature TagTuple[TagEPT, TagEPT] +test('inferTags006', + grep_errmsg(r'(TagTuple\[TagEPT, TagEPT\])', [1]), + compile, + ['-O -fno-worker-wrapper -fno-cpr-anal -fno-full-laziness -ddump-stg-tags ' + '-dno-typeable-binds -dsuppress-uniques']) test('T24806', grep_errmsg('^\\(T24806\\.\\$wgo'), compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) ===================================== testsuite/tests/simplStg/should_compile/inferTags005.hs ===================================== @@ -0,0 +1,39 @@ +{-# LANGUAGE UnboxedTuples #-} +module EnforceEpt005 where + +-- If we have +-- f x y = +-- join j = +-- <rhs> -- <TagTuple[TagEPT, TagEPT]]> +-- in case x of +-- 1 -> j +-- 2 -> j +-- _ -> +-- <something> -- <TagTuple[TagEPT, TagEPT]]> + +-- Consider the case where rhs and something both represent a tag value of <TagTuple[TagEPT, TagEPT]]> +-- In this case we want `f` to also give rise to TagFun [TagTuple[TagEPT, TagEPT]]] + +-- To achieve this we have to recognize j as a zero-arity function equivalent +-- which is what this test checks. + +-- The payoff is in `g` `r` is then known to be tagged, so `S r` needs no eval. +-- Only an unboxed tuple result exposes this. + +-- We disable worker/wrapper and CPR so `f` matches more closely the tests source. + +data T = A Int Int Int Int Int Int | B + +f :: Int -> Int -> (# T, T #) +f x y = case x of + 0 -> j + 1 -> j + _ -> (# B, B #) + where + j = (# A (y+1) (y*2) (y-3) (y*y) (y+x) (y*x), B #) +{-# NOINLINE f #-} + +data S = S !T + +g :: Int -> Int -> S +g x y = case f x y of (# r, _ #) -> S r ===================================== testsuite/tests/simplStg/should_compile/inferTags005.stderr ===================================== @@ -0,0 +1,2 @@ +TagTuple[TagEPT, TagEPT] +TagTuple[TagEPT, TagEPT] ===================================== testsuite/tests/simplStg/should_compile/inferTags006.hs ===================================== @@ -0,0 +1,31 @@ +{-# LANGUAGE UnboxedTuples #-} +module EnforceEpt006 where + +-- If we have +-- f x y = +-- join j = +-- <rhs> -- TagBottoming +-- in case x of +-- 1 -> j +-- 2 -> j +-- _ -> +-- <something> -- <TagTuple[TagEPT, TagEPT]]> + +-- Similar to inferTage005 we want to give `f` the signature: TagFun <TagTuple[TagEPT, TagEPT]]> +-- This requires us to give `j` a `TagFun[TagBottoming]` signature, which is safe because +-- either its execution will diverge, or the resulting tuple *will* have two +-- tagged values. + +data T = A Int Int Int Int Int Int | B + +f :: Int -> Int -> (# T, T #) +-- This case-of-case is just here to be optimized into a nullary join point. +f x y = case (case x of { 0 -> False; 1 -> False; _ -> True }) of + False -> error ("f: bad input " ++ show x ++ " " ++ show y ++ " " ++ show (x*y)) + True -> (# A (y+1) (y*2) (y-3) (y*y) (y+x) (y*x), B #) +{-# NOINLINE f #-} + +data S = S !T + +g :: Int -> Int -> S +g x y = case f x y of (# r, _ #) -> S r ===================================== testsuite/tests/simplStg/should_compile/inferTags006.stderr ===================================== @@ -0,0 +1 @@ +TagTuple[TagEPT, TagEPT] ===================================== testsuite/tests/simplStg/should_run/InferTags007_A.hs ===================================== @@ -0,0 +1,20 @@ +-- We suppress arity and LfInfo with the option. +{-# OPTIONS_GHC -fomit-interface-pragmas #-} +module InferTags007_A (fun, caf, bot, con) where + +fun :: Int -> Int +fun x = x + 1 +{-# NOINLINE fun #-} + +-- A CAF/thunk +caf :: [Int] +caf = map (* 2) [1 .. 10] +{-# NOINLINE caf #-} + +bot :: Int -> Int +bot _ = error "bot called" +{-# NOINLINE bot #-} + +con :: Maybe Int +con = Just 42 +{-# NOINLINE con #-} ===================================== testsuite/tests/simplStg/should_run/T27831.hs ===================================== @@ -0,0 +1,35 @@ +-- Regression test for #27831: a bottoming function stored in a strict +-- constructor field. +-- +-- Different parts of the tag inference machinery didn't agree on weither or not +-- a bottoming function should be treated as a EPT value, leading to a segfault. +module Main (main) where + +import Control.Exception +import GHC.Exts.Heap (GenClosure(..), getClosureData) +import System.Exit + +data T = MkT Int !(Int -> Int) + +t :: T +t = MkT 1 (\_ -> error "T27831") +{-# NOINLINE t #-} + +f :: () -> T +f _ = t +{-# OPAQUE f #-} + +main :: IO () +main = do + c <- getClosureData t + case c of + ThunkClosure{} -> putStrLn "FAIL: ThunkClosure" >> exitFailure + APClosure{} -> putStrLn "FAIL: APClosure" >> exitFailure + _ -> putStrLn "OK: not a thunk" + + case f () of MkT n _ -> print n + + r <- try (evaluate (case t of MkT _ g -> g 1)) + case r of + Left (ErrorCall msg) -> putStrLn ("OK: " ++ msg) + Right v -> putStrLn ("FAIL: got " ++ show v) >> exitFailure ===================================== testsuite/tests/simplStg/should_run/T27831.stdout ===================================== @@ -0,0 +1,3 @@ +OK: not a thunk +1 +OK: T27831 ===================================== testsuite/tests/simplStg/should_run/all.T ===================================== @@ -3,13 +3,15 @@ # extra run flags # expected process return value, if not zero -# Only compile with optimisation +# Only run optimised code, native and interpreted: +# We now generate bytecode from STG so we should test native and bytecode. def f( name, opts ): - opts.only_ways = ['optasm'] + opts.only_ways = ['optasm', 'ghci-opt'] setTestOpts(f) -test('T9291', normal, compile_and_run, ['']) +# Breakpoint ticks would break CSE which this tests. +test('T9291', [omit_ways(['ghci']), extra_hc_opts('-fno-break-points')], compile_and_run, ['']) test('T13536', normal, compile_and_run, ['']) test('T13536a', @@ -20,6 +22,15 @@ test('T13536a', test('inferTags001', normal, multimod_compile_and_run, ['inferTags001', 'inferTags001_a']) test('T22042', [extra_files(['T22042a.hs']),only_ways('normal'),unless(have_dynamic(), skip)], makefile_test, ['T22042']) -test('T23783', normal, multimod_compile_and_run, ['T23783', '-O -v0']) -test('unpack_enum', normal, compile_and_run, ['']) -test('T27005a', normal, compile_and_run, ['']) + +# Depends on tag inference being similarly effective for bytecode which it is not yet. +test('T23783', omit_ghci, multimod_compile_and_run, ['T23783', '-O -v0']) + +# Requires UNPACK which needs -O +test('unpack_enum', omit_ways(['ghci']), compile_and_run, ['']) + +# Tests that tag inference optimizes well, which is not the case for bytecode or +# when we insert profiling ticks. +test('T27005a', omit_ways(ghci_ways + prof_ways), compile_and_run, ['']) +test('T27831', omit_ways(ghci_ways + prof_ways), compile_and_run, ['']) +test('inferTags007', [extra_files(['InferTags007_A.hs'])], multimod_compile_and_run, ['inferTags007', '-O -v0']) ===================================== testsuite/tests/simplStg/should_run/inferTags007.hs ===================================== @@ -0,0 +1,109 @@ +{-# LANGUAGE MagicHash #-} +-- This test sanity checks the tag info we generate for imported binders which +-- have no real info in the .hi file. +-- +-- This is important to avoid running into cases where we optimistically +-- generated better information based on things like type than the +-- compiled code actually provided. For example GHCi doesn't ensure tagging +-- of constructors. +module Main (main) where + +import Control.Exception +import Control.Monad +import GHC.Exts (Addr#) +import GHC.Exts.Heap (GenClosure(..), getClosureData) +import GHC.Internal.Control.Exception.Base (patError) +import System.Exit + +import qualified InferTags007_A as A + +data S a = S !a + +data P = MkP !(Addr# -> Int) + +-- Put the imported values into a strict field of a top level Con +con_top_fun :: S (Int -> Int) +con_top_fun = S A.fun +{-# NOINLINE con_top_fun #-} + +con_top_caf :: S [Int] +con_top_caf = S A.caf +{-# NOINLINE con_top_caf #-} + +con_top_bot :: S (Int -> Int) +con_top_bot = S A.bot +{-# NOINLINE con_top_bot #-} + +con_top_con :: S (Maybe Int) +con_top_con = S A.con +{-# NOINLINE con_top_con #-} + +con_top_pat :: P +con_top_pat = MkP patError +{-# NOINLINE con_top_pat #-} + +-- Put the imported values into a strict field of a Con inside a rhs +expr_fun :: () -> S (Int -> Int) +expr_fun _ = S A.fun +{-# OPAQUE expr_fun #-} + +expr_caf :: () -> S [Int] +expr_caf _ = S A.caf +{-# OPAQUE expr_caf #-} + +expr_bot :: () -> S (Int -> Int) +expr_bot _ = S A.bot +{-# OPAQUE expr_bot #-} + +expr_con :: () -> S (Maybe Int) +expr_con _ = S A.con +{-# OPAQUE expr_con #-} + +-- Actually use the field. +use_S_head :: S [Int] -> Int +use_S_head (S xs) = case xs of { (y:_) -> y; [] -> -1 } +{-# NOINLINE use_S_head #-} + +use_S_fromJust :: S (Maybe Int) -> Int +use_S_fromJust (S m) = case m of { Just x -> x; Nothing -> -1 } +{-# NOINLINE use_S_fromJust #-} + +use_S_apply :: S (Int -> Int) -> Int +use_S_apply (S f) = f 1 +{-# NOINLINE use_S_apply #-} + +checkNotThunk :: String -> a -> IO () +checkNotThunk name x = do + c <- getClosureData x + case c of + ThunkClosure{} -> putStrLn ("FAIL: " ++ name ++ " is a thunk") >> exitFailure + APClosure{} -> putStrLn ("FAIL: " ++ name ++ " is an AP") >> exitFailure + _ -> pure () + +-- Pattern matching binds the field itself, so no selector thunk is involved. +checkField :: String -> S a -> IO () +checkField name (S x) = checkNotThunk name x +{-# NOINLINE checkField #-} + +main :: IO () +main = do + -- Check if the pointer in the strict field is a thunk. + checkField "con_top_caf" con_top_caf + checkField "con_top_fun" con_top_fun + checkField "con_top_bot" con_top_bot + checkField "con_top_con" con_top_con + case con_top_pat of MkP f -> checkNotThunk "con_top_pat" f + checkField "expr_caf" (expr_caf ()) + checkField "expr_fun" (expr_fun ()) + checkField "expr_bot" (expr_bot ()) + checkField "expr_con" (expr_con ()) + + -- Actually execute a case on the contents of the field. + print (use_S_head con_top_caf, use_S_head (expr_caf ())) + print (use_S_fromJust con_top_con, use_S_fromJust (expr_con ())) + print (use_S_apply con_top_fun, use_S_apply (expr_fun ())) + forM_ [con_top_bot, expr_bot ()] $ \s -> do + r <- try (evaluate (use_S_apply s)) + case r of + Left (ErrorCall msg) -> putStrLn ("OK: " ++ msg) + Right v -> putStrLn ("FAIL: got " ++ show v) >> exitFailure ===================================== testsuite/tests/simplStg/should_run/inferTags007.stdout ===================================== @@ -0,0 +1,5 @@ +(2,2) +(42,42) +(2,2) +OK: bot called +OK: bot called View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/ec64d9d27632dfc833786cc6f58e41e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/ec64d9d27632dfc833786cc6f58e41e… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][wip/apk/tag-strict-bot] Fix a few tag inference bugs.
by Andreas Klebinger (＠AndreasK) 23 Sep '26

23 Sep '26

Andreas Klebinger pushed to branch wip/apk/tag-strict-bot at Glasgow Haskell Compiler / GHC Commits: 8a51f7e6 by Andreas Klebinger at 2026-09-23T12:01:20+00:00 Fix a few tag inference bugs. * Treat bottoming functions and nullary join points as functions. * When generating bytecode don't rely on imported tag sigs. Fixes #27831, #27841 and #27842. - - - - - 21 changed files: - + changelog.d/T27831-bottoming-strict-field - + changelog.d/T27842-bytecode-imported-tags - compiler/GHC/Stg/EnforceEpt.hs - compiler/GHC/Stg/EnforceEpt/Rewrite.hs - compiler/GHC/Stg/EnforceEpt/Types.hs - + testsuite/tests/bytecode/T27842.hs - + testsuite/tests/bytecode/T27842.stdout - + testsuite/tests/bytecode/T27842A.hs - + testsuite/tests/bytecode/T27842N.hs - testsuite/tests/bytecode/all.T - testsuite/tests/simplStg/should_compile/all.T - + testsuite/tests/simplStg/should_compile/inferTags005.hs - + testsuite/tests/simplStg/should_compile/inferTags005.stderr - + testsuite/tests/simplStg/should_compile/inferTags006.hs - + testsuite/tests/simplStg/should_compile/inferTags006.stderr - + testsuite/tests/simplStg/should_run/InferTags007_A.hs - + testsuite/tests/simplStg/should_run/T27831.hs - + testsuite/tests/simplStg/should_run/T27831.stdout - testsuite/tests/simplStg/should_run/all.T - + testsuite/tests/simplStg/should_run/inferTags007.hs - + testsuite/tests/simplStg/should_run/inferTags007.stdout Changes: ===================================== changelog.d/T27831-bottoming-strict-field ===================================== @@ -0,0 +1,8 @@ +section: compiler +issues: #27831 +mrs: !TODO +synopsis: + Fix a segfault that could occur when a bottoming function was stored in a strict field. +description: + This was happening when a function that always diverges (e.g. ``\_ -> error "..."``) was stored in a strict field, and the constructor was pattern matched on + in "nearby" code where the structure of the constructor application was still visible to GHC. ===================================== changelog.d/T27842-bytecode-imported-tags ===================================== @@ -0,0 +1,6 @@ +section: bytecode +issues: #27842 +mrs: !TODO +synopsis: + Fix a segfault caused by reusing interface files generated with + ``-fbyte-code-and-object-code`` for interpreter sessions using ``-fprefer-byte-code``. \ No newline at end of file ===================================== compiler/GHC/Stg/EnforceEpt.hs ===================================== @@ -334,9 +334,15 @@ a) Tags for let-bindings: b) When referencing ids from other modules the Cmm backend will try to put a proper tag on these references through various means. When doing analysis we usually predict these cases to improve precision of the analysis. - But to my knowledge the bytecode generator makes no such attempts so we must - not infer imported bindings as tagged. - This is handled in GHC.Stg.EnforceEpt.Types.lookupInfo + The bytecode generator gives fewer guarantees about what it tags. + So we simply assume it fails to tag binders, even in the cases where it does. + + This is handled in GHC.Stg.EnforceEpt.Types.argTagInfo + + Eventually we will want to update the Analysis and bco code gen to uphold and + take advantage of tag inference at least to some degree. But for now it's + not a perf benefit for interpreted code, and essentially only run to uphold + the "strict field invariant"/EPT Invariant described in EPT enforcement. -} @@ -359,7 +365,7 @@ enforceEpt ppr_opts !for_bytecode logger this_mod stg_binds = do -- Rewrite STG to uphold the strict field invariant us_t <- mkSplitUniqSupply StgTag - let rewritten_binds = {-# SCC "StgEptRewrite" #-} rewriteTopBinds this_mod us_t stg_binds_w_tags :: [TgStgTopBinding] + let rewritten_binds = {-# SCC "StgEptRewrite" #-} rewriteTopBinds for_bytecode this_mod us_t stg_binds_w_tags :: [TgStgTopBinding] return (rewritten_binds,export_tag_info) @@ -414,12 +420,14 @@ inferTagExpr env (StgApp fun args) | isDeadEndAppSig (idDmdSig fun) (length args) = TagBottoming - | fun_arity == 0 -- Unknown arity => Thunk or unknown call + | not (isJoinId fun) -- zero arity join ids behave like functions. + , fun_arity == 0 -- Unknown arity => Thunk or unknown call = TagDunno -- Imported function with known return tag | Just (TagFun res_info) <- tagSigInfo (idInfo fun) , fun_arity == length args -- Saturated + , not (te_bytecode env) -- #27842 = res_info -- Local function with known return tag @@ -613,8 +621,8 @@ it safely any tag sig we like. So we give it TagBottoming, as it allows the combined tag sig of the case expression to be the combination of all non-bottoming branches. -NB: After the analysis is done we go back to treating bottoming functions as -untagged to ensure they are evaluated as expected in code like: +NB: We now distinguish functions from values. Allowing us to treat bottom functions +as tagged, while still doing the right thing for bottom values in code like: case bottom_id of { ...} ===================================== compiler/GHC/Stg/EnforceEpt/Rewrite.hs ===================================== @@ -13,7 +13,7 @@ import GHC.Builtin.PrimOps ( PrimOp(..) ) import GHC.Types.Basic ( CbvMark (..), isMarkedCbv , TopLevelFlag(..), isTopLevel ) import GHC.Types.Id -import GHC.Types.Name +import GHC.Types.Name ( nameIsLocalOrFrom ) import GHC.Types.Unique.Supply import GHC.Types.Unique.FM import GHC.Types.RepType @@ -22,10 +22,7 @@ import GHC.Unit.Types import GHC.Core.DataCon import GHC.Core ( AltCon(..) ) -import GHC.Core.Type - -import GHC.StgToCmm.Types -import GHC.StgToCmm.Closure (importedIdLFInfo) +import GHC.Core.Type ( definitelyLiftedType ) import GHC.Stg.Utils import GHC.Stg.Syntax as StgSyn @@ -41,7 +38,7 @@ import GHC.Stg.EnforceEpt.Types import Control.Monad -newtype RM a = RM { unRM :: (State (UniqFM Id TagSig, UniqSupply, Module, IdSet) a) } +newtype RM a = RM { unRM :: (State (UniqFM Id TagSig, UniqSupply, Module, IdSet, Bool) a) } deriving (Functor, Monad, Applicative) ------------------------------------------------------------ @@ -108,29 +105,34 @@ when building the free variable list. instance MonadUnique RM where getUniqueSupplyM = RM $ do - (m, us, mod,lcls) <- get + (m, us, mod,lcls,for_bytecode) <- get let (us1, us2) = splitUniqSupply us - (put) (m,us2,mod,lcls) + (put) (m,us2,mod,lcls,for_bytecode) return us1 getMap :: RM (UniqFM Id TagSig) -getMap = RM $ ((\(fst,_,_,_) -> fst) <$> get) +getMap = RM $ ((\(fst,_,_,_,_) -> fst) <$> get) setMap :: (UniqFM Id TagSig) -> RM () setMap !m = RM $ do - (_,us,mod,lcls) <- get - put (m, us,mod,lcls) - -getMod :: RM Module -getMod = RM $ ( (\(_,_,thrd,_) -> thrd) <$> get) + (_,us,mod,lcls,for_bytecode) <- get + put (m, us,mod,lcls,for_bytecode) getFVs :: RM IdSet -getFVs = RM $ ((\(_,_,_,lcls) -> lcls) <$> get) +getFVs = RM $ ((\(_,_,_,lcls,_) -> lcls) <$> get) setFVs :: IdSet -> RM () setFVs !fvs = RM $ do - (tag_map,us,mod,_lcls) <- get - put (tag_map, us,mod,fvs) + (tag_map,us,mod,_lcls,for_bytecode) <- get + put (tag_map, us,mod,fvs,for_bytecode) + +getMod :: RM Module +getMod = RM $ ( (\(_,_,c,_,_) -> c) <$> get) + +-- | Are we generating bytecode? Must agree with the flag the analysis ran +-- with, so both sides make the same tagging decisions. +getForBytecode :: RM Bool +getForBytecode = RM $ ((\(_,_,_,_,for_bytecode) -> for_bytecode) <$> get) -- Rewrite the RHS(s) while making the id and it's sig available -- to determine if things are tagged/need to be captured as FV. @@ -238,51 +240,26 @@ indicates a bug in the tag inference implementation. For this reason we assert that we are running in interactive mode if a lookup fails. -} isTagged :: Id -> RM Bool -isTagged v - -- See Note [Bottom functions are TagBottoming] - | isDeadEndId v = pure False - | otherwise = do +isTagged v = do + for_bytecode <- getForBytecode this_mod <- getMod - -- See Note [Tag inference for interactive contexts] - let lookupDefault v = assertPpr (isInteractiveModule this_mod) - (text "unknown Id:" <> ppr this_mod <+> ppr v) - (TagVal TagDunno) - case nameIsLocalOrFrom this_mod (idName v) of - True - | definitelyUnliftedType (idType v) - -- NB: v might be the Id of a representation-polymorphic join point, - -- so we shouldn't use isUnliftedType here. See T22212. - -> return True - | otherwise -> do -- Local binding - !s <- getMap - let !sig = lookupWithDefaultUFM s (lookupDefault v) v - return $ case sig of - TagFun _ -> True -- function closure is tagged - TagVal TagDunno -> False - TagVal TagEPT -> True - TagVal TagBottoming -> True - TagVal (TagTuple _) -> True -- Consider unboxed tuples tagged. - -- Imported - False -> return $! - -- Determine whether it is tagged from the LFInfo of the imported id. - -- See Note [The LFInfo of Imported Ids] - case importedIdLFInfo v of - -- Function, applied not entered. - LFReEntrant {} - -> True - -- Thunks need to be entered. - LFThunk {} - -> False - -- LFCon means we already know the tag, and it's tagged. - LFCon {} - -> True - LFUnknown {} - -> False - LFUnlifted {} -- Unboxed, tagging irrelevant - -> True - LFLetNoEscape {} - -- Shouldn't be possible. I don't think we can export letNoEscapes - -> True + s <- getMap + let get_env_sig = lookupUFM s + massertPpr + -- Assert the env is complete for local lifted binders, which means either + -- - The binder is present in the env + -- - The binder is not a local lifted binder or comes from a ghci context + (isJust (get_env_sig v) + -- See Note [Tag inference for interactive contexts] + || isInteractiveModule this_mod + || not (nameIsLocalOrFrom this_mod (idName v)) + || not (definitelyLiftedType (idType v))) + (text "unknown Id:" <> ppr this_mod <+> ppr v) + -- TODO: We could refactor the whole pass such that we also set id_tagSig + -- for every imported id. But this likely comes with a heavy allocation + -- overhead so for now we just ensure to use the same logic across analysis + -- and rewriter. + pure $! isTaggedInfo $ argTagInfo for_bytecode (get_env_sig v) (StgVarArg v) isArgTagged :: StgArg -> RM Bool @@ -299,11 +276,12 @@ mkLocalArgId id = do --------------------------- -rewriteTopBinds :: Module -> UniqSupply -> [GenStgTopBinding 'InferTaggedBinders] -> [TgStgTopBinding] -rewriteTopBinds mod us binds = +rewriteTopBinds :: Bool -- ^ Generating bytecode? + -> Module -> UniqSupply -> [GenStgTopBinding 'InferTaggedBinders] -> [TgStgTopBinding] +rewriteTopBinds for_bytecode mod us binds = let doBinds = mapM rewriteTop binds - in evalState (unRM doBinds) (mempty, us, mod, mempty) + in evalState (unRM doBinds) (mempty, us, mod, mempty, for_bytecode) rewriteTop :: InferStgTopBinding -> RM TgStgTopBinding rewriteTop (StgTopStringLit v s) = return $! (StgTopStringLit v s) ===================================== compiler/GHC/Stg/EnforceEpt/Types.hs ===================================== @@ -12,7 +12,7 @@ where import GHC.Prelude import GHC.Core.DataCon -import GHC.Core.Type (isUnliftedType) +import GHC.Core.Type (isUnliftedType, definitelyUnliftedType) import GHC.Types.Id import GHC.Stg.Syntax import GHC.Stg.EnforceEpt.TagSig as TagSig @@ -22,6 +22,7 @@ import GHC.Utils.Misc( zipWithEqual ) import GHC.Utils.Panic import GHC.StgToCmm.Types +import GHC.StgToCmm.Closure (importedIdLFInfo) {- ********************************************************************* * * @@ -97,31 +98,37 @@ lookupReturnInfo env fun = case lookupVarEnv (te_env env) fun of Just (TagVal _) -> Nothing Nothing -> Nothing --- | Look up a value-level tag for an argument: either from the env (where --- a function-typed argument flattens to TagEPT — its closure is tagged) --- or derived from information on the variable itself. -lookupInfo :: TagEnv p -> StgArg -> TagInfo -lookupInfo env (StgVarArg var) +{-# INLINE argTagInfo #-} -- Specialize for the call site. +-- | Look up a value-level tag. +-- +-- If we can do so faster avoid inspecting the env and compute the info from the Id. +-- If we can't check the provided env value or fall back to safe defaults. +argTagInfo :: Bool -> (Maybe TagSig) -> StgArg -> TagInfo +argTagInfo _for_bytecode _env_sig (StgLitArg{}) = TagEPT +argTagInfo for_bytecode env_sig (StgVarArg var) -- Nullary data constructors like True, False | Just dc <- isDataConWorkId_maybe var , isNullaryRepDataCon dc , not for_bytecode = TagEPT - | isUnliftedType (idType var) + -- NB: v might be the Id of a representation-polymorphic join point, + -- so we shouldn't use isUnliftedType here. See T22212. + | definitelyUnliftedType (idType var) = TagEPT -- Variables in the environment. A function binding flattens to TagEPT -- since a function closure pointer is properly tagged; its return info -- is not relevant when the function is used as a value. - | Just sig <- lookupVarEnv (te_env env) var + | Just sig <- env_sig = case sig of TagVal info -> info TagFun _ -> TagEPT - | Just lf_info <- idLFInfo_maybe var - , not for_bytecode - = case lf_info of + | lf_info <- importedIdLFInfo var -- will make up LFInfo if not present. + = if for_bytecode then TagDunno + else + case lf_info of -- Function, tagged (with arity) LFReEntrant {} -> TagEPT @@ -138,13 +145,14 @@ lookupInfo env (StgVarArg var) -- Shouldn't be possible. I don't think we can export letNoEscapes LFLetNoEscape {} -> panic "LFLetNoEscape exported" - | otherwise - = TagDunno - where - for_bytecode = te_bytecode env - -lookupInfo _ (StgLitArg {}) - = TagEPT +-- | Look up a value-level tag for an argument: either from the env (where +-- a function-typed argument flattens to TagEPT — its closure is tagged) +-- or derived from information on the variable itself. +lookupInfo :: TagEnv p -> StgArg -> TagInfo +lookupInfo env arg@(StgVarArg var) = + let env_sig = (lookupVarEnv (te_env env) var) + in argTagInfo (te_bytecode env) env_sig arg +lookupInfo _env (StgLitArg{}) = TagEPT isDunnoSig :: TagSig -> Bool isDunnoSig (TagVal TagDunno) = True ===================================== testsuite/tests/bytecode/T27842.hs ===================================== @@ -0,0 +1,42 @@ +{-# LANGUAGE UnboxedTuples #-} +{-# OPTIONS_GHC -fno-worker-wrapper -fno-cpr-anal #-} +-- Regression test for #27842. +-- +-- The basic rundown is this: +-- We produce one interface file, however we store information dependent on the +-- code generation method in the interface file. +-- +-- We happen to pick the native code information to store in the interface file. +-- +-- When we compile a module M this way, and then generate byte code for code +-- depending on M based on M.hi we will assume certain exported definitions are EPT +-- tagged, despite the interpreter doing no such thing. +-- +-- This then led to crashes in the interpreter. +-- +-- We test three kinds of imported definitions: +-- * mk uses fun, a function whose TagSig says its result is tagged. +-- * bar uses just_con, a value whose LFInfo says it is a constructor. +-- * baz uses gt_con, the same for a nullary constructor. +module Main where + +import T27842A (fun, just_con, gt_con) +import T27842N (S(..), use_S, M(..), use_M, N(..), use_N) + +mk :: Int -> S +mk x = case fun x of (# xs, _ #) -> S xs +{-# NOINLINE mk #-} + +bar :: M +bar = M just_con +{-# NOINLINE bar #-} + +baz :: N +baz = N gt_con +{-# NOINLINE baz #-} + +main :: IO () +main = do + print (use_S (mk 42)) + print (use_M bar) + print (use_N baz) ===================================== testsuite/tests/bytecode/T27842.stdout ===================================== @@ -0,0 +1,3 @@ +42 +42 +3 ===================================== testsuite/tests/bytecode/T27842A.hs ===================================== @@ -0,0 +1,19 @@ +{-# LANGUAGE UnboxedTuples #-} +{-# OPTIONS_GHC -fno-worker-wrapper -fno-cpr-anal #-} +module T27842A (fun, just_con, gt_con) where + +-- The native EPT run gives fun the TagSig TagFun[TagTuple[TagEPT, TagDunno]]: +fun :: Int -> (# [Int], Int #) +fun x = let xs = x : xs in (# xs, x #) +{-# NOINLINE fun #-} + +-- In native code a static constructor, in bytecode an unevaluated closure. +just_con :: Maybe Int +just_con = Just 42 +{-# NOINLINE just_con #-} + +-- The same for a nullary constructor. Without its pointer tag, the object code +-- in T27842N would take the LT alternative, so GT shows the difference. +gt_con :: Ordering +gt_con = GT +{-# NOINLINE gt_con #-} ===================================== testsuite/tests/bytecode/T27842N.hs ===================================== @@ -0,0 +1,26 @@ +{-# OPTIONS_GHC -fno-byte-code-and-object-code #-} +-- We compile this module as native code, depending on A's interface file. +-- A itself is loaded into GHCi, despite it's interface file being generated based +-- on native code generation. +module T27842N (S(..), use_S, M(..), use_M, N(..), use_N) where + +data S = S ![Int] + +-- We take apart the strict constructor value and branch on the value in its field. +-- If the field content is not EPT this causes undefined behaviour. + +use_S :: S -> Int +use_S (S xs) = case xs of { (y:_) -> y; [] -> -1 } +{-# NOINLINE use_S #-} + +data M = M !(Maybe Int) + +use_M :: M -> Int +use_M (M m) = case m of { Just x -> x; Nothing -> -1 } +{-# NOINLINE use_M #-} + +data N = N !Ordering + +use_N :: N -> Int +use_N (N o) = case o of { LT -> 1; EQ -> 2; GT -> 3 } +{-# NOINLINE use_N #-} ===================================== testsuite/tests/bytecode/all.T ===================================== @@ -17,3 +17,12 @@ test('T26216', extra_files(["T26216_aux.hs"]), ghci_script, ['T26216.script']) test('T27001', [extra_files(['T27001.hs']), req_interp], run_command, ['{compiler} -e main -O -fno-unoptimized-core-for-interpreter T27001.hs']) + +# Bytecode must not trust tag information from imported interfaces, which +# comes from native code (#27842): neither the TagSig of an imported function +# nor the LFInfo of an imported value (with and without constructor fields). +test('T27842', [extra_files(['T27842A.hs', 'T27842N.hs']), req_interp], + run_command, + ['{compiler} -e main -O -fno-unoptimized-core-for-interpreter ' + '-fobject-code -fbyte-code-and-object-code -fwrite-byte-code -fprefer-byte-code ' + 'T27842.hs']) ===================================== testsuite/tests/simplStg/should_compile/all.T ===================================== @@ -25,5 +25,17 @@ test('inferTags003', [ only_ways(['optasm']), ], compile, ['-ddump-cmm -dno-typeable-binds -O']) test('inferTags004', normal, compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) test('T27005b', normal, compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) +# Both f and the join point j should have a signature TagTuple[TagEPT, TagEPT] +test('inferTags005', + grep_errmsg(r'(TagTuple\[TagEPT, TagEPT\])', [1]), + compile, + ['-O -fno-worker-wrapper -fno-cpr-anal -ddump-stg-tags ' + '-dno-typeable-binds -dsuppress-uniques']) +# The function needs to have a signature TagTuple[TagEPT, TagEPT] +test('inferTags006', + grep_errmsg(r'(TagTuple\[TagEPT, TagEPT\])', [1]), + compile, + ['-O -fno-worker-wrapper -fno-cpr-anal -fno-full-laziness -ddump-stg-tags ' + '-dno-typeable-binds -dsuppress-uniques']) test('T24806', grep_errmsg('^\\(T24806\\.\\$wgo'), compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) ===================================== testsuite/tests/simplStg/should_compile/inferTags005.hs ===================================== @@ -0,0 +1,39 @@ +{-# LANGUAGE UnboxedTuples #-} +module EnforceEpt005 where + +-- If we have +-- f x y = +-- join j = +-- <rhs> -- <TagTuple[TagEPT, TagEPT]]> +-- in case x of +-- 1 -> j +-- 2 -> j +-- _ -> +-- <something> -- <TagTuple[TagEPT, TagEPT]]> + +-- Consider the case where rhs and something both represent a tag value of <TagTuple[TagEPT, TagEPT]]> +-- In this case we want `f` to also give rise to TagFun [TagTuple[TagEPT, TagEPT]]] + +-- To achieve this we have to recognize j as a zero-arity function equivalent +-- which is what this test checks. + +-- The payoff is in `g` `r` is then known to be tagged, so `S r` needs no eval. +-- Only an unboxed tuple result exposes this. + +-- We disable worker/wrapper and CPR so `f` matches more closely the tests source. + +data T = A Int Int Int Int Int Int | B + +f :: Int -> Int -> (# T, T #) +f x y = case x of + 0 -> j + 1 -> j + _ -> (# B, B #) + where + j = (# A (y+1) (y*2) (y-3) (y*y) (y+x) (y*x), B #) +{-# NOINLINE f #-} + +data S = S !T + +g :: Int -> Int -> S +g x y = case f x y of (# r, _ #) -> S r ===================================== testsuite/tests/simplStg/should_compile/inferTags005.stderr ===================================== @@ -0,0 +1,2 @@ +TagTuple[TagEPT, TagEPT] +TagTuple[TagEPT, TagEPT] ===================================== testsuite/tests/simplStg/should_compile/inferTags006.hs ===================================== @@ -0,0 +1,31 @@ +{-# LANGUAGE UnboxedTuples #-} +module EnforceEpt006 where + +-- If we have +-- f x y = +-- join j = +-- <rhs> -- TagBottoming +-- in case x of +-- 1 -> j +-- 2 -> j +-- _ -> +-- <something> -- <TagTuple[TagEPT, TagEPT]]> + +-- Similar to inferTage005 we want to give `f` the signature: TagFun <TagTuple[TagEPT, TagEPT]]> +-- This requires us to give `j` a `TagFun[TagBottoming]` signature, which is safe because +-- either its execution will diverge, or the resulting tuple *will* have two +-- tagged values. + +data T = A Int Int Int Int Int Int | B + +f :: Int -> Int -> (# T, T #) +-- This case-of-case is just here to be optimized into a nullary join point. +f x y = case (case x of { 0 -> False; 1 -> False; _ -> True }) of + False -> error ("f: bad input " ++ show x ++ " " ++ show y ++ " " ++ show (x*y)) + True -> (# A (y+1) (y*2) (y-3) (y*y) (y+x) (y*x), B #) +{-# NOINLINE f #-} + +data S = S !T + +g :: Int -> Int -> S +g x y = case f x y of (# r, _ #) -> S r ===================================== testsuite/tests/simplStg/should_compile/inferTags006.stderr ===================================== @@ -0,0 +1 @@ +TagTuple[TagEPT, TagEPT] ===================================== testsuite/tests/simplStg/should_run/InferTags007_A.hs ===================================== @@ -0,0 +1,20 @@ +-- We suppress arity and LfInfo with the option. +{-# OPTIONS_GHC -fomit-interface-pragmas #-} +module InferTags007_A (fun, caf, bot, con) where + +fun :: Int -> Int +fun x = x + 1 +{-# NOINLINE fun #-} + +-- A CAF/thunk +caf :: [Int] +caf = map (* 2) [1 .. 10] +{-# NOINLINE caf #-} + +bot :: Int -> Int +bot _ = error "bot called" +{-# NOINLINE bot #-} + +con :: Maybe Int +con = Just 42 +{-# NOINLINE con #-} ===================================== testsuite/tests/simplStg/should_run/T27831.hs ===================================== @@ -0,0 +1,35 @@ +-- Regression test for #27831: a bottoming function stored in a strict +-- constructor field. +-- +-- Different parts of the tag inference machinery didn't agree on weither or not +-- a bottoming function should be treated as a EPT value, leading to a segfault. +module Main (main) where + +import Control.Exception +import GHC.Exts.Heap (GenClosure(..), getClosureData) +import System.Exit + +data T = MkT Int !(Int -> Int) + +t :: T +t = MkT 1 (\_ -> error "T27831") +{-# NOINLINE t #-} + +f :: () -> T +f _ = t +{-# OPAQUE f #-} + +main :: IO () +main = do + c <- getClosureData t + case c of + ThunkClosure{} -> putStrLn "FAIL: ThunkClosure" >> exitFailure + APClosure{} -> putStrLn "FAIL: APClosure" >> exitFailure + _ -> putStrLn "OK: not a thunk" + + case f () of MkT n _ -> print n + + r <- try (evaluate (case t of MkT _ g -> g 1)) + case r of + Left (ErrorCall msg) -> putStrLn ("OK: " ++ msg) + Right v -> putStrLn ("FAIL: got " ++ show v) >> exitFailure ===================================== testsuite/tests/simplStg/should_run/T27831.stdout ===================================== @@ -0,0 +1,3 @@ +OK: not a thunk +1 +OK: T27831 ===================================== testsuite/tests/simplStg/should_run/all.T ===================================== @@ -3,13 +3,15 @@ # extra run flags # expected process return value, if not zero -# Only compile with optimisation +# Only run optimised code, native and interpreted: +# We now generate bytecode from STG so we should test native and bytecode. def f( name, opts ): - opts.only_ways = ['optasm'] + opts.only_ways = ['optasm', 'ghci-opt'] setTestOpts(f) -test('T9291', normal, compile_and_run, ['']) +# Breakpoint ticks would break CSE which this tests. +test('T9291', [omit_ways(['ghci']), extra_hc_opts('-fno-break-points')], compile_and_run, ['']) test('T13536', normal, compile_and_run, ['']) test('T13536a', @@ -20,6 +22,15 @@ test('T13536a', test('inferTags001', normal, multimod_compile_and_run, ['inferTags001', 'inferTags001_a']) test('T22042', [extra_files(['T22042a.hs']),only_ways('normal'),unless(have_dynamic(), skip)], makefile_test, ['T22042']) -test('T23783', normal, multimod_compile_and_run, ['T23783', '-O -v0']) -test('unpack_enum', normal, compile_and_run, ['']) -test('T27005a', normal, compile_and_run, ['']) + +# Depends on tag inference being similarly effective for bytecode which it is not yet. +test('T23783', omit_ghci, multimod_compile_and_run, ['T23783', '-O -v0']) + +# Requires UNPACK which needs -O +test('unpack_enum', omit_ways(['ghci']), compile_and_run, ['']) + +# Tests that tag inference optimizes well, which is not the case for bytecode or +# when we insert profiling ticks. +test('T27005a', omit_ways(ghci_ways + prof_ways), compile_and_run, ['']) +test('T27831', omit_ways(ghci_ways + prof_ways), compile_and_run, ['']) +test('inferTags007', [extra_files(['InferTags007_A.hs'])], multimod_compile_and_run, ['inferTags007', '-O -v0']) ===================================== testsuite/tests/simplStg/should_run/inferTags007.hs ===================================== @@ -0,0 +1,109 @@ +{-# LANGUAGE MagicHash #-} +-- This test sanity checks the tag info we generate for imported binders which +-- have no real info in the .hi file. +-- +-- This is important to avoid running into cases where we optimistically +-- generated better information based on things like type than the +-- compiled code actually provided. For example GHCi doesn't ensure tagging +-- of constructors. +module Main (main) where + +import Control.Exception +import Control.Monad +import GHC.Exts (Addr#) +import GHC.Exts.Heap (GenClosure(..), getClosureData) +import GHC.Internal.Control.Exception.Base (patError) +import System.Exit + +import qualified InferTags007_A as A + +data S a = S !a + +data P = MkP !(Addr# -> Int) + +-- Put the imported values into a strict field of a top level Con +con_top_fun :: S (Int -> Int) +con_top_fun = S A.fun +{-# NOINLINE con_top_fun #-} + +con_top_caf :: S [Int] +con_top_caf = S A.caf +{-# NOINLINE con_top_caf #-} + +con_top_bot :: S (Int -> Int) +con_top_bot = S A.bot +{-# NOINLINE con_top_bot #-} + +con_top_con :: S (Maybe Int) +con_top_con = S A.con +{-# NOINLINE con_top_con #-} + +con_top_pat :: P +con_top_pat = MkP patError +{-# NOINLINE con_top_pat #-} + +-- Put the imported values into a strict field of a Con inside a rhs +expr_fun :: () -> S (Int -> Int) +expr_fun _ = S A.fun +{-# OPAQUE expr_fun #-} + +expr_caf :: () -> S [Int] +expr_caf _ = S A.caf +{-# OPAQUE expr_caf #-} + +expr_bot :: () -> S (Int -> Int) +expr_bot _ = S A.bot +{-# OPAQUE expr_bot #-} + +expr_con :: () -> S (Maybe Int) +expr_con _ = S A.con +{-# OPAQUE expr_con #-} + +-- Actually use the field. +use_S_head :: S [Int] -> Int +use_S_head (S xs) = case xs of { (y:_) -> y; [] -> -1 } +{-# NOINLINE use_S_head #-} + +use_S_fromJust :: S (Maybe Int) -> Int +use_S_fromJust (S m) = case m of { Just x -> x; Nothing -> -1 } +{-# NOINLINE use_S_fromJust #-} + +use_S_apply :: S (Int -> Int) -> Int +use_S_apply (S f) = f 1 +{-# NOINLINE use_S_apply #-} + +checkNotThunk :: String -> a -> IO () +checkNotThunk name x = do + c <- getClosureData x + case c of + ThunkClosure{} -> putStrLn ("FAIL: " ++ name ++ " is a thunk") >> exitFailure + APClosure{} -> putStrLn ("FAIL: " ++ name ++ " is an AP") >> exitFailure + _ -> pure () + +-- Pattern matching binds the field itself, so no selector thunk is involved. +checkField :: String -> S a -> IO () +checkField name (S x) = checkNotThunk name x +{-# NOINLINE checkField #-} + +main :: IO () +main = do + -- Check if the pointer in the strict field is a thunk. + checkField "con_top_caf" con_top_caf + checkField "con_top_fun" con_top_fun + checkField "con_top_bot" con_top_bot + checkField "con_top_con" con_top_con + case con_top_pat of MkP f -> checkNotThunk "con_top_pat" f + checkField "expr_caf" (expr_caf ()) + checkField "expr_fun" (expr_fun ()) + checkField "expr_bot" (expr_bot ()) + checkField "expr_con" (expr_con ()) + + -- Actually execute a case on the contents of the field. + print (use_S_head con_top_caf, use_S_head (expr_caf ())) + print (use_S_fromJust con_top_con, use_S_fromJust (expr_con ())) + print (use_S_apply con_top_fun, use_S_apply (expr_fun ())) + forM_ [con_top_bot, expr_bot ()] $ \s -> do + r <- try (evaluate (use_S_apply s)) + case r of + Left (ErrorCall msg) -> putStrLn ("OK: " ++ msg) + Right v -> putStrLn ("FAIL: got " ++ show v) >> exitFailure ===================================== testsuite/tests/simplStg/should_run/inferTags007.stdout ===================================== @@ -0,0 +1,5 @@ +(2,2) +(42,42) +(2,2) +OK: bot called +OK: bot called View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/8a51f7e6cd0f0a0eafd1dac69836a39… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/8a51f7e6cd0f0a0eafd1dac69836a39… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][wip/apk/tag-strict-bot] Fix a few tag inference bugs.
by Andreas Klebinger (＠AndreasK) 23 Sep '26

23 Sep '26

Andreas Klebinger pushed to branch wip/apk/tag-strict-bot at Glasgow Haskell Compiler / GHC Commits: 13739009 by Andreas Klebinger at 2026-09-23T11:58:28+00:00 Fix a few tag inference bugs. * Treat bottoming functions and nullary join points as functions. * When generating bytecode don't rely on imported tag sigs. Fixes #27831 and #27842. - - - - - 21 changed files: - + changelog.d/T27831-bottoming-strict-field - + changelog.d/T27842-bytecode-imported-tags - compiler/GHC/Stg/EnforceEpt.hs - compiler/GHC/Stg/EnforceEpt/Rewrite.hs - compiler/GHC/Stg/EnforceEpt/Types.hs - + testsuite/tests/bytecode/T27842.hs - + testsuite/tests/bytecode/T27842.stdout - + testsuite/tests/bytecode/T27842A.hs - + testsuite/tests/bytecode/T27842N.hs - testsuite/tests/bytecode/all.T - testsuite/tests/simplStg/should_compile/all.T - + testsuite/tests/simplStg/should_compile/inferTags005.hs - + testsuite/tests/simplStg/should_compile/inferTags005.stderr - + testsuite/tests/simplStg/should_compile/inferTags006.hs - + testsuite/tests/simplStg/should_compile/inferTags006.stderr - + testsuite/tests/simplStg/should_run/InferTags007_A.hs - + testsuite/tests/simplStg/should_run/T27831.hs - + testsuite/tests/simplStg/should_run/T27831.stdout - testsuite/tests/simplStg/should_run/all.T - + testsuite/tests/simplStg/should_run/inferTags007.hs - + testsuite/tests/simplStg/should_run/inferTags007.stdout Changes: ===================================== changelog.d/T27831-bottoming-strict-field ===================================== @@ -0,0 +1,8 @@ +section: compiler +issues: #27831 +mrs: !TODO +synopsis: + Fix a segfault that could occur when a bottoming function was stored in a strict field. +description: + This was happening when a function that always diverges (e.g. ``\_ -> error "..."``) was stored in a strict field, and the constructor was pattern matched on + in "nearby" code where the structure of the constructor application was still visible to GHC. ===================================== changelog.d/T27842-bytecode-imported-tags ===================================== @@ -0,0 +1,6 @@ +section: bytecode +issues: #27842 +mrs: !TODO +synopsis: + Fix a segfault caused by reusing interface files generated with + ``-fbyte-code-and-object-code`` for interpreter sessions using ``-fprefer-byte-code``. \ No newline at end of file ===================================== compiler/GHC/Stg/EnforceEpt.hs ===================================== @@ -334,9 +334,15 @@ a) Tags for let-bindings: b) When referencing ids from other modules the Cmm backend will try to put a proper tag on these references through various means. When doing analysis we usually predict these cases to improve precision of the analysis. - But to my knowledge the bytecode generator makes no such attempts so we must - not infer imported bindings as tagged. - This is handled in GHC.Stg.EnforceEpt.Types.lookupInfo + The bytecode generator gives fewer guarantees about what it tags. + So we simply assume it fails to tag binders, even in the cases where it does. + + This is handled in GHC.Stg.EnforceEpt.Types.argTagInfo + + Eventually we will want to update the Analysis and bco code gen to uphold and + take advantage of tag inference at least to some degree. But for now it's + not a perf benefit for interpreted code, and essentially only run to uphold + the "strict field invariant"/EPT Invariant described in EPT enforcement. -} @@ -359,7 +365,7 @@ enforceEpt ppr_opts !for_bytecode logger this_mod stg_binds = do -- Rewrite STG to uphold the strict field invariant us_t <- mkSplitUniqSupply StgTag - let rewritten_binds = {-# SCC "StgEptRewrite" #-} rewriteTopBinds this_mod us_t stg_binds_w_tags :: [TgStgTopBinding] + let rewritten_binds = {-# SCC "StgEptRewrite" #-} rewriteTopBinds for_bytecode this_mod us_t stg_binds_w_tags :: [TgStgTopBinding] return (rewritten_binds,export_tag_info) @@ -414,12 +420,14 @@ inferTagExpr env (StgApp fun args) | isDeadEndAppSig (idDmdSig fun) (length args) = TagBottoming - | fun_arity == 0 -- Unknown arity => Thunk or unknown call + | not (isJoinId fun) -- zero arity join ids behave like functions. + , fun_arity == 0 -- Unknown arity => Thunk or unknown call = TagDunno -- Imported function with known return tag | Just (TagFun res_info) <- tagSigInfo (idInfo fun) , fun_arity == length args -- Saturated + , not (te_bytecode env) -- #27842 = res_info -- Local function with known return tag @@ -613,8 +621,8 @@ it safely any tag sig we like. So we give it TagBottoming, as it allows the combined tag sig of the case expression to be the combination of all non-bottoming branches. -NB: After the analysis is done we go back to treating bottoming functions as -untagged to ensure they are evaluated as expected in code like: +NB: We now distinguish functions from values. Allowing us to treat bottom functions +as tagged, while still doing the right thing for bottom values in code like: case bottom_id of { ...} ===================================== compiler/GHC/Stg/EnforceEpt/Rewrite.hs ===================================== @@ -13,7 +13,7 @@ import GHC.Builtin.PrimOps ( PrimOp(..) ) import GHC.Types.Basic ( CbvMark (..), isMarkedCbv , TopLevelFlag(..), isTopLevel ) import GHC.Types.Id -import GHC.Types.Name +import GHC.Types.Name ( nameIsLocalOrFrom ) import GHC.Types.Unique.Supply import GHC.Types.Unique.FM import GHC.Types.RepType @@ -22,10 +22,7 @@ import GHC.Unit.Types import GHC.Core.DataCon import GHC.Core ( AltCon(..) ) -import GHC.Core.Type - -import GHC.StgToCmm.Types -import GHC.StgToCmm.Closure (importedIdLFInfo) +import GHC.Core.Type ( definitelyLiftedType ) import GHC.Stg.Utils import GHC.Stg.Syntax as StgSyn @@ -41,7 +38,7 @@ import GHC.Stg.EnforceEpt.Types import Control.Monad -newtype RM a = RM { unRM :: (State (UniqFM Id TagSig, UniqSupply, Module, IdSet) a) } +newtype RM a = RM { unRM :: (State (UniqFM Id TagSig, UniqSupply, Module, IdSet, Bool) a) } deriving (Functor, Monad, Applicative) ------------------------------------------------------------ @@ -108,29 +105,34 @@ when building the free variable list. instance MonadUnique RM where getUniqueSupplyM = RM $ do - (m, us, mod,lcls) <- get + (m, us, mod,lcls,for_bytecode) <- get let (us1, us2) = splitUniqSupply us - (put) (m,us2,mod,lcls) + (put) (m,us2,mod,lcls,for_bytecode) return us1 getMap :: RM (UniqFM Id TagSig) -getMap = RM $ ((\(fst,_,_,_) -> fst) <$> get) +getMap = RM $ ((\(fst,_,_,_,_) -> fst) <$> get) setMap :: (UniqFM Id TagSig) -> RM () setMap !m = RM $ do - (_,us,mod,lcls) <- get - put (m, us,mod,lcls) - -getMod :: RM Module -getMod = RM $ ( (\(_,_,thrd,_) -> thrd) <$> get) + (_,us,mod,lcls,for_bytecode) <- get + put (m, us,mod,lcls,for_bytecode) getFVs :: RM IdSet -getFVs = RM $ ((\(_,_,_,lcls) -> lcls) <$> get) +getFVs = RM $ ((\(_,_,_,lcls,_) -> lcls) <$> get) setFVs :: IdSet -> RM () setFVs !fvs = RM $ do - (tag_map,us,mod,_lcls) <- get - put (tag_map, us,mod,fvs) + (tag_map,us,mod,_lcls,for_bytecode) <- get + put (tag_map, us,mod,fvs,for_bytecode) + +getMod :: RM Module +getMod = RM $ ( (\(_,_,c,_,_) -> c) <$> get) + +-- | Are we generating bytecode? Must agree with the flag the analysis ran +-- with, so both sides make the same tagging decisions. +getForBytecode :: RM Bool +getForBytecode = RM $ ((\(_,_,_,_,for_bytecode) -> for_bytecode) <$> get) -- Rewrite the RHS(s) while making the id and it's sig available -- to determine if things are tagged/need to be captured as FV. @@ -238,51 +240,26 @@ indicates a bug in the tag inference implementation. For this reason we assert that we are running in interactive mode if a lookup fails. -} isTagged :: Id -> RM Bool -isTagged v - -- See Note [Bottom functions are TagBottoming] - | isDeadEndId v = pure False - | otherwise = do +isTagged v = do + for_bytecode <- getForBytecode this_mod <- getMod - -- See Note [Tag inference for interactive contexts] - let lookupDefault v = assertPpr (isInteractiveModule this_mod) - (text "unknown Id:" <> ppr this_mod <+> ppr v) - (TagVal TagDunno) - case nameIsLocalOrFrom this_mod (idName v) of - True - | definitelyUnliftedType (idType v) - -- NB: v might be the Id of a representation-polymorphic join point, - -- so we shouldn't use isUnliftedType here. See T22212. - -> return True - | otherwise -> do -- Local binding - !s <- getMap - let !sig = lookupWithDefaultUFM s (lookupDefault v) v - return $ case sig of - TagFun _ -> True -- function closure is tagged - TagVal TagDunno -> False - TagVal TagEPT -> True - TagVal TagBottoming -> True - TagVal (TagTuple _) -> True -- Consider unboxed tuples tagged. - -- Imported - False -> return $! - -- Determine whether it is tagged from the LFInfo of the imported id. - -- See Note [The LFInfo of Imported Ids] - case importedIdLFInfo v of - -- Function, applied not entered. - LFReEntrant {} - -> True - -- Thunks need to be entered. - LFThunk {} - -> False - -- LFCon means we already know the tag, and it's tagged. - LFCon {} - -> True - LFUnknown {} - -> False - LFUnlifted {} -- Unboxed, tagging irrelevant - -> True - LFLetNoEscape {} - -- Shouldn't be possible. I don't think we can export letNoEscapes - -> True + s <- getMap + let get_env_sig = lookupUFM s + massertPpr + -- Assert the env is complete for local lifted binders, which means either + -- - The binder is present in the env + -- - The binder is not a local lifted binder or comes from a ghci context + (isJust (get_env_sig v) + -- See Note [Tag inference for interactive contexts] + || isInteractiveModule this_mod + || not (nameIsLocalOrFrom this_mod (idName v)) + || not (definitelyLiftedType (idType v))) + (text "unknown Id:" <> ppr this_mod <+> ppr v) + -- TODO: We could refactor the whole pass such that we also set id_tagSig + -- for every imported id. But this likely comes with a heavy allocation + -- overhead so for now we just ensure to use the same logic across analysis + -- and rewriter. + pure $! isTaggedInfo $ argTagInfo for_bytecode (get_env_sig v) (StgVarArg v) isArgTagged :: StgArg -> RM Bool @@ -299,11 +276,12 @@ mkLocalArgId id = do --------------------------- -rewriteTopBinds :: Module -> UniqSupply -> [GenStgTopBinding 'InferTaggedBinders] -> [TgStgTopBinding] -rewriteTopBinds mod us binds = +rewriteTopBinds :: Bool -- ^ Generating bytecode? + -> Module -> UniqSupply -> [GenStgTopBinding 'InferTaggedBinders] -> [TgStgTopBinding] +rewriteTopBinds for_bytecode mod us binds = let doBinds = mapM rewriteTop binds - in evalState (unRM doBinds) (mempty, us, mod, mempty) + in evalState (unRM doBinds) (mempty, us, mod, mempty, for_bytecode) rewriteTop :: InferStgTopBinding -> RM TgStgTopBinding rewriteTop (StgTopStringLit v s) = return $! (StgTopStringLit v s) ===================================== compiler/GHC/Stg/EnforceEpt/Types.hs ===================================== @@ -12,7 +12,7 @@ where import GHC.Prelude import GHC.Core.DataCon -import GHC.Core.Type (isUnliftedType) +import GHC.Core.Type (isUnliftedType, definitelyUnliftedType) import GHC.Types.Id import GHC.Stg.Syntax import GHC.Stg.EnforceEpt.TagSig as TagSig @@ -22,6 +22,7 @@ import GHC.Utils.Misc( zipWithEqual ) import GHC.Utils.Panic import GHC.StgToCmm.Types +import GHC.StgToCmm.Closure (importedIdLFInfo) {- ********************************************************************* * * @@ -97,31 +98,37 @@ lookupReturnInfo env fun = case lookupVarEnv (te_env env) fun of Just (TagVal _) -> Nothing Nothing -> Nothing --- | Look up a value-level tag for an argument: either from the env (where --- a function-typed argument flattens to TagEPT — its closure is tagged) --- or derived from information on the variable itself. -lookupInfo :: TagEnv p -> StgArg -> TagInfo -lookupInfo env (StgVarArg var) +{-# INLINE argTagInfo #-} -- Specialize for the call site. +-- | Look up a value-level tag. +-- +-- If we can do so faster avoid inspecting the env and compute the info from the Id. +-- If we can't check the provided env value or fall back to safe defaults. +argTagInfo :: Bool -> (Maybe TagSig) -> StgArg -> TagInfo +argTagInfo _for_bytecode _env_sig (StgLitArg{}) = TagEPT +argTagInfo for_bytecode env_sig (StgVarArg var) -- Nullary data constructors like True, False | Just dc <- isDataConWorkId_maybe var , isNullaryRepDataCon dc , not for_bytecode = TagEPT - | isUnliftedType (idType var) + -- NB: v might be the Id of a representation-polymorphic join point, + -- so we shouldn't use isUnliftedType here. See T22212. + | definitelyUnliftedType (idType var) = TagEPT -- Variables in the environment. A function binding flattens to TagEPT -- since a function closure pointer is properly tagged; its return info -- is not relevant when the function is used as a value. - | Just sig <- lookupVarEnv (te_env env) var + | Just sig <- env_sig = case sig of TagVal info -> info TagFun _ -> TagEPT - | Just lf_info <- idLFInfo_maybe var - , not for_bytecode - = case lf_info of + | lf_info <- importedIdLFInfo var -- will make up LFInfo if not present. + = if for_bytecode then TagDunno + else + case lf_info of -- Function, tagged (with arity) LFReEntrant {} -> TagEPT @@ -138,13 +145,14 @@ lookupInfo env (StgVarArg var) -- Shouldn't be possible. I don't think we can export letNoEscapes LFLetNoEscape {} -> panic "LFLetNoEscape exported" - | otherwise - = TagDunno - where - for_bytecode = te_bytecode env - -lookupInfo _ (StgLitArg {}) - = TagEPT +-- | Look up a value-level tag for an argument: either from the env (where +-- a function-typed argument flattens to TagEPT — its closure is tagged) +-- or derived from information on the variable itself. +lookupInfo :: TagEnv p -> StgArg -> TagInfo +lookupInfo env arg@(StgVarArg var) = + let env_sig = (lookupVarEnv (te_env env) var) + in argTagInfo (te_bytecode env) env_sig arg +lookupInfo _env (StgLitArg{}) = TagEPT isDunnoSig :: TagSig -> Bool isDunnoSig (TagVal TagDunno) = True ===================================== testsuite/tests/bytecode/T27842.hs ===================================== @@ -0,0 +1,42 @@ +{-# LANGUAGE UnboxedTuples #-} +{-# OPTIONS_GHC -fno-worker-wrapper -fno-cpr-anal #-} +-- Regression test for #27842. +-- +-- The basic rundown is this: +-- We produce one interface file, however we store information dependent on the +-- code generation method in the interface file. +-- +-- We happen to pick the native code information to store in the interface file. +-- +-- When we compile a module M this way, and then generate byte code for code +-- depending on M based on M.hi we will assume certain exported definitions are EPT +-- tagged, despite the interpreter doing no such thing. +-- +-- This then led to crashes in the interpreter. +-- +-- We test three kinds of imported definitions: +-- * mk uses fun, a function whose TagSig says its result is tagged. +-- * bar uses just_con, a value whose LFInfo says it is a constructor. +-- * baz uses gt_con, the same for a nullary constructor. +module Main where + +import T27842A (fun, just_con, gt_con) +import T27842N (S(..), use_S, M(..), use_M, N(..), use_N) + +mk :: Int -> S +mk x = case fun x of (# xs, _ #) -> S xs +{-# NOINLINE mk #-} + +bar :: M +bar = M just_con +{-# NOINLINE bar #-} + +baz :: N +baz = N gt_con +{-# NOINLINE baz #-} + +main :: IO () +main = do + print (use_S (mk 42)) + print (use_M bar) + print (use_N baz) ===================================== testsuite/tests/bytecode/T27842.stdout ===================================== @@ -0,0 +1,3 @@ +42 +42 +3 ===================================== testsuite/tests/bytecode/T27842A.hs ===================================== @@ -0,0 +1,19 @@ +{-# LANGUAGE UnboxedTuples #-} +{-# OPTIONS_GHC -fno-worker-wrapper -fno-cpr-anal #-} +module T27842A (fun, just_con, gt_con) where + +-- The native EPT run gives fun the TagSig TagFun[TagTuple[TagEPT, TagDunno]]: +fun :: Int -> (# [Int], Int #) +fun x = let xs = x : xs in (# xs, x #) +{-# NOINLINE fun #-} + +-- In native code a static constructor, in bytecode an unevaluated closure. +just_con :: Maybe Int +just_con = Just 42 +{-# NOINLINE just_con #-} + +-- The same for a nullary constructor. Without its pointer tag, the object code +-- in T27842N would take the LT alternative, so GT shows the difference. +gt_con :: Ordering +gt_con = GT +{-# NOINLINE gt_con #-} ===================================== testsuite/tests/bytecode/T27842N.hs ===================================== @@ -0,0 +1,26 @@ +{-# OPTIONS_GHC -fno-byte-code-and-object-code #-} +-- We compile this module as native code, depending on A's interface file. +-- A itself is loaded into GHCi, despite it's interface file being generated based +-- on native code generation. +module T27842N (S(..), use_S, M(..), use_M, N(..), use_N) where + +data S = S ![Int] + +-- We take apart the strict constructor value and branch on the value in its field. +-- If the field content is not EPT this causes undefined behaviour. + +use_S :: S -> Int +use_S (S xs) = case xs of { (y:_) -> y; [] -> -1 } +{-# NOINLINE use_S #-} + +data M = M !(Maybe Int) + +use_M :: M -> Int +use_M (M m) = case m of { Just x -> x; Nothing -> -1 } +{-# NOINLINE use_M #-} + +data N = N !Ordering + +use_N :: N -> Int +use_N (N o) = case o of { LT -> 1; EQ -> 2; GT -> 3 } +{-# NOINLINE use_N #-} ===================================== testsuite/tests/bytecode/all.T ===================================== @@ -17,3 +17,12 @@ test('T26216', extra_files(["T26216_aux.hs"]), ghci_script, ['T26216.script']) test('T27001', [extra_files(['T27001.hs']), req_interp], run_command, ['{compiler} -e main -O -fno-unoptimized-core-for-interpreter T27001.hs']) + +# Bytecode must not trust tag information from imported interfaces, which +# comes from native code (#27842): neither the TagSig of an imported function +# nor the LFInfo of an imported value (with and without constructor fields). +test('T27842', [extra_files(['T27842A.hs', 'T27842N.hs']), req_interp], + run_command, + ['{compiler} -e main -O -fno-unoptimized-core-for-interpreter ' + '-fobject-code -fbyte-code-and-object-code -fwrite-byte-code -fprefer-byte-code ' + 'T27842.hs']) ===================================== testsuite/tests/simplStg/should_compile/all.T ===================================== @@ -25,5 +25,17 @@ test('inferTags003', [ only_ways(['optasm']), ], compile, ['-ddump-cmm -dno-typeable-binds -O']) test('inferTags004', normal, compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) test('T27005b', normal, compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) +# Both f and the join point j should have a signature TagTuple[TagEPT, TagEPT] +test('inferTags005', + grep_errmsg(r'(TagTuple\[TagEPT, TagEPT\])', [1]), + compile, + ['-O -fno-worker-wrapper -fno-cpr-anal -ddump-stg-tags ' + '-dno-typeable-binds -dsuppress-uniques']) +# The function needs to have a signature TagTuple[TagEPT, TagEPT] +test('inferTags006', + grep_errmsg(r'(TagTuple\[TagEPT, TagEPT\])', [1]), + compile, + ['-O -fno-worker-wrapper -fno-cpr-anal -fno-full-laziness -ddump-stg-tags ' + '-dno-typeable-binds -dsuppress-uniques']) test('T24806', grep_errmsg('^\\(T24806\\.\\$wgo'), compile, ['-O -ddump-stg-tags -dno-typeable-binds -dsuppress-uniques']) ===================================== testsuite/tests/simplStg/should_compile/inferTags005.hs ===================================== @@ -0,0 +1,39 @@ +{-# LANGUAGE UnboxedTuples #-} +module EnforceEpt005 where + +-- If we have +-- f x y = +-- join j = +-- <rhs> -- <TagTuple[TagEPT, TagEPT]]> +-- in case x of +-- 1 -> j +-- 2 -> j +-- _ -> +-- <something> -- <TagTuple[TagEPT, TagEPT]]> + +-- Consider the case where rhs and something both represent a tag value of <TagTuple[TagEPT, TagEPT]]> +-- In this case we want `f` to also give rise to TagFun [TagTuple[TagEPT, TagEPT]]] + +-- To achieve this we have to recognize j as a zero-arity function equivalent +-- which is what this test checks. + +-- The payoff is in `g` `r` is then known to be tagged, so `S r` needs no eval. +-- Only an unboxed tuple result exposes this. + +-- We disable worker/wrapper and CPR so `f` matches more closely the tests source. + +data T = A Int Int Int Int Int Int | B + +f :: Int -> Int -> (# T, T #) +f x y = case x of + 0 -> j + 1 -> j + _ -> (# B, B #) + where + j = (# A (y+1) (y*2) (y-3) (y*y) (y+x) (y*x), B #) +{-# NOINLINE f #-} + +data S = S !T + +g :: Int -> Int -> S +g x y = case f x y of (# r, _ #) -> S r ===================================== testsuite/tests/simplStg/should_compile/inferTags005.stderr ===================================== @@ -0,0 +1,2 @@ +TagTuple[TagEPT, TagEPT] +TagTuple[TagEPT, TagEPT] ===================================== testsuite/tests/simplStg/should_compile/inferTags006.hs ===================================== @@ -0,0 +1,31 @@ +{-# LANGUAGE UnboxedTuples #-} +module EnforceEpt006 where + +-- If we have +-- f x y = +-- join j = +-- <rhs> -- TagBottoming +-- in case x of +-- 1 -> j +-- 2 -> j +-- _ -> +-- <something> -- <TagTuple[TagEPT, TagEPT]]> + +-- Similar to inferTage005 we want to give `f` the signature: TagFun <TagTuple[TagEPT, TagEPT]]> +-- This requires us to give `j` a `TagFun[TagBottoming]` signature, which is safe because +-- either its execution will diverge, or the resulting tuple *will* have two +-- tagged values. + +data T = A Int Int Int Int Int Int | B + +f :: Int -> Int -> (# T, T #) +-- This case-of-case is just here to be optimized into a nullary join point. +f x y = case (case x of { 0 -> False; 1 -> False; _ -> True }) of + False -> error ("f: bad input " ++ show x ++ " " ++ show y ++ " " ++ show (x*y)) + True -> (# A (y+1) (y*2) (y-3) (y*y) (y+x) (y*x), B #) +{-# NOINLINE f #-} + +data S = S !T + +g :: Int -> Int -> S +g x y = case f x y of (# r, _ #) -> S r ===================================== testsuite/tests/simplStg/should_compile/inferTags006.stderr ===================================== @@ -0,0 +1 @@ +TagTuple[TagEPT, TagEPT] ===================================== testsuite/tests/simplStg/should_run/InferTags007_A.hs ===================================== @@ -0,0 +1,20 @@ +-- We suppress arity and LfInfo with the option. +{-# OPTIONS_GHC -fomit-interface-pragmas #-} +module InferTags007_A (fun, caf, bot, con) where + +fun :: Int -> Int +fun x = x + 1 +{-# NOINLINE fun #-} + +-- A CAF/thunk +caf :: [Int] +caf = map (* 2) [1 .. 10] +{-# NOINLINE caf #-} + +bot :: Int -> Int +bot _ = error "bot called" +{-# NOINLINE bot #-} + +con :: Maybe Int +con = Just 42 +{-# NOINLINE con #-} ===================================== testsuite/tests/simplStg/should_run/T27831.hs ===================================== @@ -0,0 +1,35 @@ +-- Regression test for #27831: a bottoming function stored in a strict +-- constructor field. +-- +-- Different parts of the tag inference machinery didn't agree on weither or not +-- a bottoming function should be treated as a EPT value, leading to a segfault. +module Main (main) where + +import Control.Exception +import GHC.Exts.Heap (GenClosure(..), getClosureData) +import System.Exit + +data T = MkT Int !(Int -> Int) + +t :: T +t = MkT 1 (\_ -> error "T27831") +{-# NOINLINE t #-} + +f :: () -> T +f _ = t +{-# OPAQUE f #-} + +main :: IO () +main = do + c <- getClosureData t + case c of + ThunkClosure{} -> putStrLn "FAIL: ThunkClosure" >> exitFailure + APClosure{} -> putStrLn "FAIL: APClosure" >> exitFailure + _ -> putStrLn "OK: not a thunk" + + case f () of MkT n _ -> print n + + r <- try (evaluate (case t of MkT _ g -> g 1)) + case r of + Left (ErrorCall msg) -> putStrLn ("OK: " ++ msg) + Right v -> putStrLn ("FAIL: got " ++ show v) >> exitFailure ===================================== testsuite/tests/simplStg/should_run/T27831.stdout ===================================== @@ -0,0 +1,3 @@ +OK: not a thunk +1 +OK: T27831 ===================================== testsuite/tests/simplStg/should_run/all.T ===================================== @@ -3,13 +3,15 @@ # extra run flags # expected process return value, if not zero -# Only compile with optimisation +# Only run optimised code, native and interpreted: +# We now generate bytecode from STG so we should test native and bytecode. def f( name, opts ): - opts.only_ways = ['optasm'] + opts.only_ways = ['optasm', 'ghci-opt'] setTestOpts(f) -test('T9291', normal, compile_and_run, ['']) +# Breakpoint ticks would break CSE which this tests. +test('T9291', [omit_ways(['ghci']), extra_hc_opts('-fno-break-points')], compile_and_run, ['']) test('T13536', normal, compile_and_run, ['']) test('T13536a', @@ -20,6 +22,15 @@ test('T13536a', test('inferTags001', normal, multimod_compile_and_run, ['inferTags001', 'inferTags001_a']) test('T22042', [extra_files(['T22042a.hs']),only_ways('normal'),unless(have_dynamic(), skip)], makefile_test, ['T22042']) -test('T23783', normal, multimod_compile_and_run, ['T23783', '-O -v0']) -test('unpack_enum', normal, compile_and_run, ['']) -test('T27005a', normal, compile_and_run, ['']) + +# Depends on tag inference being similarly effective for bytecode which it is not yet. +test('T23783', omit_ghci, multimod_compile_and_run, ['T23783', '-O -v0']) + +# Requires UNPACK which needs -O +test('unpack_enum', omit_ways(['ghci']), compile_and_run, ['']) + +# Tests that tag inference optimizes well, which is not the case for bytecode or +# when we insert profiling ticks. +test('T27005a', omit_ways(ghci_ways + prof_ways), compile_and_run, ['']) +test('T27831', omit_ways(ghci_ways + prof_ways), compile_and_run, ['']) +test('inferTags007', [extra_files(['InferTags007_A.hs'])], multimod_compile_and_run, ['inferTags007', '-O -v0']) ===================================== testsuite/tests/simplStg/should_run/inferTags007.hs ===================================== @@ -0,0 +1,109 @@ +{-# LANGUAGE MagicHash #-} +-- This test sanity checks the tag info we generate for imported binders which +-- have no real info in the .hi file. +-- +-- This is important to avoid running into cases where we optimistically +-- generated better information based on things like type than the +-- compiled code actually provided. For example GHCi doesn't ensure tagging +-- of constructors. +module Main (main) where + +import Control.Exception +import Control.Monad +import GHC.Exts (Addr#) +import GHC.Exts.Heap (GenClosure(..), getClosureData) +import GHC.Internal.Control.Exception.Base (patError) +import System.Exit + +import qualified InferTags007_A as A + +data S a = S !a + +data P = MkP !(Addr# -> Int) + +-- Put the imported values into a strict field of a top level Con +con_top_fun :: S (Int -> Int) +con_top_fun = S A.fun +{-# NOINLINE con_top_fun #-} + +con_top_caf :: S [Int] +con_top_caf = S A.caf +{-# NOINLINE con_top_caf #-} + +con_top_bot :: S (Int -> Int) +con_top_bot = S A.bot +{-# NOINLINE con_top_bot #-} + +con_top_con :: S (Maybe Int) +con_top_con = S A.con +{-# NOINLINE con_top_con #-} + +con_top_pat :: P +con_top_pat = MkP patError +{-# NOINLINE con_top_pat #-} + +-- Put the imported values into a strict field of a Con inside a rhs +expr_fun :: () -> S (Int -> Int) +expr_fun _ = S A.fun +{-# OPAQUE expr_fun #-} + +expr_caf :: () -> S [Int] +expr_caf _ = S A.caf +{-# OPAQUE expr_caf #-} + +expr_bot :: () -> S (Int -> Int) +expr_bot _ = S A.bot +{-# OPAQUE expr_bot #-} + +expr_con :: () -> S (Maybe Int) +expr_con _ = S A.con +{-# OPAQUE expr_con #-} + +-- Actually use the field. +use_S_head :: S [Int] -> Int +use_S_head (S xs) = case xs of { (y:_) -> y; [] -> -1 } +{-# NOINLINE use_S_head #-} + +use_S_fromJust :: S (Maybe Int) -> Int +use_S_fromJust (S m) = case m of { Just x -> x; Nothing -> -1 } +{-# NOINLINE use_S_fromJust #-} + +use_S_apply :: S (Int -> Int) -> Int +use_S_apply (S f) = f 1 +{-# NOINLINE use_S_apply #-} + +checkNotThunk :: String -> a -> IO () +checkNotThunk name x = do + c <- getClosureData x + case c of + ThunkClosure{} -> putStrLn ("FAIL: " ++ name ++ " is a thunk") >> exitFailure + APClosure{} -> putStrLn ("FAIL: " ++ name ++ " is an AP") >> exitFailure + _ -> pure () + +-- Pattern matching binds the field itself, so no selector thunk is involved. +checkField :: String -> S a -> IO () +checkField name (S x) = checkNotThunk name x +{-# NOINLINE checkField #-} + +main :: IO () +main = do + -- Check if the pointer in the strict field is a thunk. + checkField "con_top_caf" con_top_caf + checkField "con_top_fun" con_top_fun + checkField "con_top_bot" con_top_bot + checkField "con_top_con" con_top_con + case con_top_pat of MkP f -> checkNotThunk "con_top_pat" f + checkField "expr_caf" (expr_caf ()) + checkField "expr_fun" (expr_fun ()) + checkField "expr_bot" (expr_bot ()) + checkField "expr_con" (expr_con ()) + + -- Actually execute a case on the contents of the field. + print (use_S_head con_top_caf, use_S_head (expr_caf ())) + print (use_S_fromJust con_top_con, use_S_fromJust (expr_con ())) + print (use_S_apply con_top_fun, use_S_apply (expr_fun ())) + forM_ [con_top_bot, expr_bot ()] $ \s -> do + r <- try (evaluate (use_S_apply s)) + case r of + Left (ErrorCall msg) -> putStrLn ("OK: " ++ msg) + Right v -> putStrLn ("FAIL: got " ++ show v) >> exitFailure ===================================== testsuite/tests/simplStg/should_run/inferTags007.stdout ===================================== @@ -0,0 +1,5 @@ +(2,2) +(42,42) +(2,2) +OK: bot called +OK: bot called View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1373900916ff9a13663817ca40bb19f… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1373900916ff9a13663817ca40bb19f… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc] Pushed new branch wip/apk/tag-strict-bot
by Andreas Klebinger (＠AndreasK) 23 Sep '26

23 Sep '26

Andreas Klebinger pushed new branch wip/apk/tag-strict-bot at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/apk/tag-strict-bot You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][wip/T27737] Fix join points
by Simon Peyton Jones (＠simonpj) 23 Sep '26

23 Sep '26

Simon Peyton Jones pushed to branch wip/T27737 at Glasgow Haskell Compiler / GHC Commits: aeb276b0 by Simon Peyton Jones at 2026-09-23T09:37:52+01:00 Fix join points Split contininuations *first* - - - - - 1 changed file: - compiler/GHC/Core/Opt/Simplify/Iteration.hs Changes: ===================================== compiler/GHC/Core/Opt/Simplify/Iteration.hs ===================================== @@ -1311,21 +1311,24 @@ simplExprF1 env (Let (NonRec bndr rhs) body) cont tick (PreInlineUnconditionally bndr) ; simplExprF env' body cont } +simplExprF1 env expr@(Let {}) cont + | not (seCaseCase env) + , (inner, outer) <- splitContArgs cont + , not (contIsStop outer) + = do { expr' <- simplExprC env expr inner + ; rebuild env expr' outer } + -- Now check for a join point. It's better to do the preInlineUnconditionally -- test first, because joinPointBinding_maybe has to eta-expand, so a trivial -- binding like { j = j2 |> co } would first be eta-expanded and then inlined -- Better to test preInlineUnconditionally first. +-- +-- Must be after the seCaseCase stuff: todo: explain why +-- Example GHC.Internal.Debug simplExprF1 env (Let bind body) cont | Just bind' <- joinPointBind_maybe bind = simplJoinPointBind env bind' body cont -simplExprF1 env expr@(Let {}) cont - | not (seCaseCase env) - , (inner, outer) <- splitContArgs cont - , not (contIsStop outer) - = do { expr' <- simplExprC env expr inner - ; rebuild env expr' outer } - -- Non-recursive let simplExprF1 env (Let (NonRec bndr rhs) body) cont = {-#SCC "simplNonRecE" #-} View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/aeb276b02467316e5ef8bf5dea60a2f… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/aeb276b02467316e5ef8bf5dea60a2f… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][wip/davide/io_manager_tests] Add test modifier to test over all IO Managers
by David Eichmann (＠DavidEichmann) 23 Sep '26

23 Sep '26

David Eichmann pushed to branch wip/davide/io_manager_tests at Glasgow Haskell Compiler / GHC Commits: 1260fa33 by David Eichmann at 2026-09-23T08:32:24+01:00 Add test modifier to test over all IO Managers - - - - - 6 changed files: - testsuite/config/ghc - testsuite/driver/runtests.py - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/driver/testutil.py - testsuite/tests/rts/all.T Changes: ===================================== testsuite/config/ghc ===================================== @@ -257,7 +257,9 @@ def get_compiler_info(): ) except Exception as err: - print("Exception thrown in testsuite/config/ghc.get_compiler_info: %s", err) + # We don't throw so that we can still discover tests before we've built + # GHC (i.e. config.compiler doesn't yet exist). + print("Exception thrown in testsuite/config/ghc.get_compiler_info: ", err) else: res = p.returncode == 0 @@ -315,6 +317,61 @@ def get_compiler_info(): config.ghc_th_way = "normal" config.ghc_th_hi_ext = "hi" + # I/O manager discovery. + # + # Which I/O managers (GHC's `--io-manager` RTS flag) a given RTS build + # supports depends on the target platform and on whether the RTS is the + # threaded or non-threaded flavour (see rts/IOManager.h's + # IOMGR_ENABLED_* macros). Rather than duplicate that platform/way + # dependent logic here, we ask the RTS itself: giving it a bogus + # '--io-manager=' choice makes it print, on stderr, the list of I/O + # managers it was actually built to support (see IOManager.h's + # IOMGRS_ENABLED_STR, used when reporting the error in RtsFlags.c), + # which we then parse out. + def discover_io_managers_generic(extra_flags): + import tempfile + + test_src = 'main :: IO ()\nmain = return ()\n' + + res = [None] + + with tempfile.TemporaryDirectory() as d: + src = Path(d) / 'IOMgrProbe.hs' + src.write_text(test_src) + exe = Path(d) / ('IoMgrProbe' + config.exeext) + + # -rtsopts is needed so that the resulting binary will even + # consider an --io-manager= flag (rather than immediately + # rejecting all "unsafe" RTS options). + cmd = '{} -v0 -rtsopts -o {} {} {}'.format( + config.compiler, + exe, + src, + ' '.join(extra_flags)) + try: + cp = subprocess.run( + cmd, + shell=True, + cwd=d, + stdout=subprocess.DEVNULL, + stderr=None if config.verbose >= 3 else subprocess.DEVNULL) + if cp.returncode != 0 or not exe.exists(): + raise Exception("Error in testsuite/config/ghc.discover_io_managers: failed to compile with: {}".format(cmd)) + res = list(discover_io_managers(exe, d)) + + except Exception as err: + # We don't throw so that we can still discover tests before we've built + # GHC (i.e. config.compiler doesn't yet exist). + print("Exception thrown in testsuite/config/ghc.discover_io_managers_generic: ", err) + + return res + + config.io_managers_nonthreaded = discover_io_managers_generic([]) + config.io_managers_threaded = ( + discover_io_managers_generic(['-threaded']) if config.ghc_with_threaded_rts + else []) + config.io_managers_all = list(set(config.io_managers_nonthreaded).union(set(config.io_managers_threaded))) + config.cmm_cpp_is_gcc = test_compile( ['-c'], test_filename='test.cmm', ===================================== testsuite/driver/runtests.py ===================================== @@ -28,7 +28,7 @@ import subprocess import asyncio -from testutil import getStdout, str_warn, str_info, print_table, shorten_metric_name, str_removeprefix +from testutil import discover_io_managers, getStdout, str_warn, str_info, print_table, shorten_metric_name, str_removeprefix from testglobals import getConfig, ghc_env, TestConfig, t, \ TestOptions, brokens, PerfMetric from my_typing import TestName ===================================== testsuite/driver/testglobals.py ===================================== @@ -126,6 +126,15 @@ class TestConfig: self.way_flags = {} # type: Dict[WayName, List[str]] self.way_rts_flags = {} # type: Dict[WayName, List[str]] + # I/O managers (GHC's `--io-manager` RTS flag) supported by the threaded runtime. + self.io_managers_threaded = [] # type: List[str] + + # I/O managers (GHC's `--io-manager` RTS flag) supported by the non-threaded runtime. + self.io_managers_nonthreaded = [] # type: List[str] + + # All I/O managers (GHC's `--io-manager` RTS flag) + self.io_managers_all = [] # type: List[str] + # Do we have a functional LLVM toolchain? self.have_llvm = False @@ -366,6 +375,11 @@ class TestOptions: # add these ways to the default set self.extra_ways = [] # type: List[WayName] + # IO Managers to test (passed as the --io-manager RTS option) + # * [None] - only default IO Manager + # * [...] - list of io managers e.g. "mio" or "poll" + self.io_managers = [None] # type: List[Optional[str]] + # the result we normally expect for this test self.expect = 'pass' ===================================== testsuite/driver/testlib.py ===================================== @@ -23,7 +23,7 @@ import subprocess from testglobals import config, ghc_env, default_testopts, brokens, t, \ TestRun, TestResult, TestOptions, PerfMetric -from testutil import strip_quotes, lndir, link_or_copy_file, passed, \ +from testutil import discover_io_managers, strip_quotes, lndir, link_or_copy_file, passed, \ failBecause, residency_testing_metrics, \ stable_perf_counters, \ PassFail, badResult, str_warn, str_removeprefix @@ -569,6 +569,34 @@ def extra_ways( ways: List[WayName] ): return helper +# ----- + +def _io_managers( name: TestName, opts, io_mgrs: List[str] ) -> None: + opts.io_managers = io_mgrs + +def io_managers( io_mgrs: List[str] ): + """ + Further split test cases into the given IO Managers if available. + Available IO Managers are determined by the test case's way (threaded/non-threads) and OS. + You'll likely want to use `extra_ways(['threaded2'])` if you want to test threaded IO Managers (e.g. mio). + """ + return lambda name, opts: _io_managers(name, opts, io_mgrs) + +def all_available_io_managers( name: TestName, opts ): + """ + Further split test cases into all available IO Managers. + Available IO Managers are determined by the test case's way (threaded/non-threads) and OS. + You'll likely want to use `extra_ways(['threaded2'])` to ensure threaded IO Managers are tested (e.g. mio). + """ + _io_managers(name, opts, config.io_managers_all) + +def all_available_io_managers_except(exclude: List[str]): + """ + Further split test cases into all available (except the given excluded) IO Managers. + Available IO Managers are determined by the test case's way (threaded/non-threads) and OS. + You'll likely want to use `extra_ways(['threaded2'])` to ensure threaded IO Managers are tested (e.g. mio). + """ + return lambda name, opts: _io_managers(name, opts, list(set(config.io_managers_all) - set(exclude))) # ----- @@ -1571,6 +1599,15 @@ do_not_copy = ('.hi', '.o', '.dyn_hi' , '.dyn_o', '.out' ,'.hi-boot', '.o-boot') # 12112 +def way_supports_io_manager(way: WayName, io_manager: Optional[str]) -> bool: + # All ways support a default IO Manager + if io_manager is None: + return True + + way_is_threaded = '-threaded' in config.way_flags[way] + available_io_managers = config.io_managers_threaded if way_is_threaded else config.io_managers_nonthreaded + return io_manager in available_io_managers + async def test_common_work(name: TestName, opts, func, args) -> None: try: @@ -1619,7 +1656,22 @@ async def test_common_work(name: TestName, opts, # A test itself can request extra ways by setting opts.extra_ways all_ways = list(OrderedDict.fromkeys(all_ways + [way for way in opts.extra_ways if way not in all_ways])) - t.total_test_cases += len(all_ways) + # We split each way over available io managers + if len(opts.io_managers) == 0: + framework_fail(name, None, 'opts.io_managers is empty') + all_ways_and_io_managers = dict( + ( + way, + [io_manager + for io_manager in opts.io_managers + if way_supports_io_manager(way, io_manager) + ] + ) + for way in all_ways + ) + + for io_managers in all_ways_and_io_managers.values(): + t.total_test_cases += len(io_managers) only_ways = getTestOpts().only_ways ok_way = lambda way: \ @@ -1702,17 +1754,26 @@ async def test_common_work(name: TestName, opts, # Run the required tests... for way in do_ways: - if stopping(): - break - try: - await do_test(name, way, func, args, files) - except KeyboardInterrupt: - stopNow() - except Exception as e: - traceback.print_exc() - framework_fail(name, way, traceback.format_exc()) + for io_manager in all_ways_and_io_managers[way]: + if stopping(): + break + try: + await do_test( + name, + way, + io_manager, + func, + args, + files) + except KeyboardInterrupt: + stopNow() + except Exception as e: + traceback.print_exc() + framework_fail(name, way, traceback.format_exc()) + + for skipped_way in set(all_ways) - set(do_ways): + t.n_tests_skipped += len(all_ways_and_io_managers[skipped_way]) - t.n_tests_skipped += len(set(all_ways) - set(do_ways)) if getTestOpts().expect == 'missing-lib': t.n_missing_libs += 1 if config.cleanup and do_ways: @@ -1731,6 +1792,7 @@ async def test_common_work(name: TestName, opts, async def do_test(name: TestName, way: WayName, + io_manager: Optional[str], func: Callable[..., Awaitable[PassFail]], args, files: Set[str] @@ -1738,6 +1800,8 @@ async def do_test(name: TestName, opts = getTestOpts() full_name = name + '(' + way + ')' + if io_manager is not None: + full_name += ' (IO Manager: {})'.format(io_manager) test_n = len(allTestNames) progress_args = [ full_name, t.total_tests, test_n, [len(t.unexpected_passes), @@ -1818,7 +1882,20 @@ async def do_test(name: TestName, # Don't continue and try to run the test if the pre_cmd fails. return - result = await func(*[name,way] + args) + + func_has_io_manager_param = func in [ + backpack_run, + compile_and_run, + ghci_multiunit_script, + ghci_script, + multi_compile_and_run, + multimod_compile_and_run, + warn_and_run + ] + + io_manager_arg = [io_manager] if func_has_io_manager_param else [] + + result = await func(*[name,way] + io_manager_arg + args) if opts.expect not in ['pass', 'fail', 'missing-lib']: framework_fail(name, way, 'bad expected ' + opts.expect) @@ -1907,7 +1984,7 @@ def framework_warn(name: TestName, way: WayName, reason: str) -> None: # run_command. async def run_command( name, way, cmd ): - return await simple_run( name, WayName(''), override_options(cmd), '' ) + return await simple_run( name, WayName(''), None, override_options(cmd), '' ) async def makefile_test( name, way, target=None ): if target is None: @@ -1919,7 +1996,7 @@ async def makefile_test( name, way, target=None ): # ----------------------------------------------------------------------------- # GHCi tests -async def ghci_script( name, way, script): +async def ghci_script( name, way, io_manager, script): flags = ' '.join(get_compiler_flags()) way_flags = ' '.join(config.way_flags[way]) @@ -1930,9 +2007,9 @@ async def ghci_script( name, way, script): # NB: put way_flags before flags so that flags in all.T can override others getTestOpts().stdin = script - return await simple_run( name, way, cmd, getTestOpts().extra_run_opts ) + return await simple_run( name, way, io_manager, cmd, getTestOpts().extra_run_opts ) -async def ghci_multiunit_script( name, way, units, script): +async def ghci_multiunit_script( name, way, io_manager, units, script): flags = ' '.join(get_compiler_flags()) way_flags = ' '.join(config.way_flags[way]) unit_flags = ' '.join(['-unit @%s' % unit for unit in units]) @@ -1944,7 +2021,7 @@ async def ghci_multiunit_script( name, way, units, script): # NB: put way_flags before flags so that flags in all.T can override others getTestOpts().stdin = script - return await simple_run( name, way, cmd, getTestOpts().extra_run_opts ) + return await simple_run( name, way, io_manager, cmd, getTestOpts().extra_run_opts ) # ----------------------------------------------------------------------------- # Compile-only tests @@ -2124,7 +2201,8 @@ async def compile_grep_core(name: TestName, async def compile_and_run__(name: TestName, way: WayName, - top_mod: Path | None, + io_manager: Optional[str], + top_mod: Optional[Path], extra_mods: List[str], extra_hc_opts: str, backpack: bool=False, @@ -2166,22 +2244,22 @@ async def compile_and_run__(name: TestName, cmd = './' + name + extension # we don't check the compiler's stderr for a compile-and-run test - return await simple_run( name, way, cmd, getTestOpts().extra_run_opts ) + return await simple_run( name, way, io_manager, cmd, getTestOpts().extra_run_opts ) -async def compile_and_run( name, way, extra_hc_opts ): - return await compile_and_run__( name, way, None, [], extra_hc_opts) +async def compile_and_run( name, way, io_manager, extra_hc_opts ): + return await compile_and_run__( name, way, io_manager, None, [], extra_hc_opts) -async def backpack_run( name, way, extra_hc_opts ): - return await compile_and_run__( name, way, None, [], extra_hc_opts, backpack=True ) +async def backpack_run( name, way, io_manager, extra_hc_opts ): + return await compile_and_run__( name, way, io_manager, None, [], extra_hc_opts, backpack=True ) -async def multimod_compile_and_run( name, way, top_mod, extra_hc_opts ): - return await compile_and_run__( name, way, top_mod, [], extra_hc_opts) +async def multimod_compile_and_run( name, way, io_manager, top_mod, extra_hc_opts ): + return await compile_and_run__( name, way, io_manager, top_mod, [], extra_hc_opts) -async def multi_compile_and_run( name, way, top_mod, extra_mods, extra_hc_opts ): - return await compile_and_run__( name, way, top_mod, extra_mods, extra_hc_opts) +async def multi_compile_and_run( name, way, io_manager, top_mod, extra_mods, extra_hc_opts ): + return await compile_and_run__( name, way, io_manager, top_mod, extra_mods, extra_hc_opts) -async def warn_and_run( name, way, extra_hc_opts ): - return await compile_and_run__( name, way, None, [], extra_hc_opts, compile_stderr = True) +async def warn_and_run( name, way, io_manager, extra_hc_opts ): + return await compile_and_run__( name, way, io_manager, None, [], extra_hc_opts, compile_stderr = True) async def static_stats( name, way ): opts = getTestOpts() @@ -2388,7 +2466,7 @@ async def simple_build(name: Union[TestName, str], # from /dev/null. Route output to testname.run.stdout and # testname.run.stderr. Returns the exit code of the run. -async def simple_run(name: TestName, way: WayName, prog: str, extra_run_opts: str) -> Any: +async def simple_run(name: TestName, way: WayName, io_manager: Optional[str], prog: str, extra_run_opts: str) -> Any: opts = getTestOpts() # figure out what to use for stdin @@ -2407,6 +2485,9 @@ async def simple_run(name: TestName, way: WayName, prog: str, extra_run_opts: st my_rts_flags = rts_flags(way) + if io_manager is not None: + my_rts_flags += ' +RTS --io-manager={0} -RTS '.format(io_manager) + # Collect runtime stats if necessary: # isStatsTest and not isCompilerStatsTest(): # assume we are running a ghc compiled program. Collect stats. @@ -2432,6 +2513,12 @@ async def simple_run(name: TestName, way: WayName, prog: str, extra_run_opts: st output_file = perfStatsFile(False, name) + # Check that IO Manager is available + if io_manager is not None: + available_io_managers = discover_io_managers(prog, opts.testdir) + if io_manager not in available_io_managers: + framework_fail(name, way, 'IO Manager {} unexpectedly unavailable (available IO Managers: {}). `-non-threaded`/`-threaded` is only supported through way RTS flags (not manually added via test modifiers/args) when testing over IO Managers.'.format(io_manager, available_io_managers)) + # run the command exit_code = await runCmdPerf(opts.compiler_perf_counters, cmd, output_file, working_dir=opts.testdir, @@ -2493,7 +2580,7 @@ def rts_flags(way: WayName) -> str: async def interpreter_run(name: TestName, way: WayName, extra_hc_opts: str, - top_mod: Path | None + top_mod: Optional[Path] ) -> PassFail: opts = getTestOpts() ===================================== testsuite/driver/testutil.py ===================================== @@ -1,4 +1,5 @@ import os +import re import subprocess import shutil import tempfile @@ -179,3 +180,21 @@ def shorten_metric_name(name: str) -> str: "binary_size/if_compression(3)": "size/3", } return dic.get(name, name) + +# I/O manager discovery for a haskell binary. Returns the set of IO Manager +# strings supported by the binary +def discover_io_managers(hs_exe: Union[str, Path], cwd: Union[str, Path]) -> Set[str]: + rp = subprocess.run( + [str(hs_exe), '+RTS', '--io-manager=not-a-real-io-manager', '-RTS'], + cwd=cwd, + stdout=subprocess.DEVNULL, + stderr=subprocess.PIPE) + stderr = rp.stderr.decode('utf-8', errors='replace') + + m = re.search(r'choices are:\s*(.*)', stderr) + if not m: + raise Exception("Expected stderr output of form 'choices are: ...' but got: {}".format(stderr)) + + # 'auto' is a meta-choice (let the RTS pick a default for us), not + # an I/O manager implementation in its own right. + return set(m.group(1).split()) - {'auto'} ===================================== testsuite/tests/rts/all.T ===================================== @@ -662,8 +662,9 @@ test('T23142', [unless(debug_rts(), skip), req_interp], makefile_test, ['T23142' test('T23400', [], compile_and_run, ['-with-rtsopts -A8k']) test('IOManager', [js_skip, when(arch('wasm32'), skip), when(opsys('mingw32'), skip), - pre_cmd('$MAKE -s --no-print-directory IOManager.hs')], - compile_and_run, ['']) + pre_cmd('$MAKE -s --no-print-directory IOManager.hs'), + extra_ways(['threaded2']), all_available_io_managers_except('winio')], + compile_and_run, ['']) test('T24142', [req_target_smp], compile_and_run, ['-threaded -with-rtsopts "-N2"']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1260fa331ab8ee3133f6c6a3c59cbcd… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1260fa331ab8ee3133f6c6a3c59cbcd… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][master] Don't lose instances from shadowed imported modules with the same name
by Marge Bot (＠marge-bot) 23 Sep '26

23 Sep '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: bf17f289 by fendor at 2026-09-22T15:04:05-04:00 Don't lose instances from shadowed imported modules with the same name When we look for instances below the current module, we need to check the unit id as well when we check for whether the module is the current module, otherwise we ignore modules we import that have the same name as the import module. Adds regression test. - - - - - 10 changed files: - + changelog.d/26610 - compiler/GHC/Driver/Env.hs - + testsuite/tests/ghci/prog-mhu008/Makefile - + testsuite/tests/ghci/prog-mhu008/a/M.hs - + testsuite/tests/ghci/prog-mhu008/all.T - + testsuite/tests/ghci/prog-mhu008/b/M.hs - + testsuite/tests/ghci/prog-mhu008/prog-mhu008.script - + testsuite/tests/ghci/prog-mhu008/prog-mhu008.stdout - + testsuite/tests/ghci/prog-mhu008/unitA - + testsuite/tests/ghci/prog-mhu008/unitB Changes: ===================================== changelog.d/26610 ===================================== @@ -0,0 +1,7 @@ +section: compiler +synopsis: Fix instance resolution for shadowed modules +description: + Instances imported from modules with the same module name as the importing module + were dropped accidentally since we didn't account for the unit id of the imported module. +mrs: !16648 +issues: #26610 ===================================== compiler/GHC/Driver/Env.hs ===================================== @@ -263,13 +263,13 @@ hugCompleteSigsBelow hsc uid mn = foldr (++) [] <$> -- | Find instances visible from the given set of imports hugInstancesBelow :: HscEnv -> UnitId -> ModuleNameWithIsBoot -> IO (InstEnv, [FamInst]) hugInstancesBelow hsc_env uid mnwib = do - let mn = gwib_mod mnwib + let mn = mkModule uid (gwib_mod mnwib) (insts, famInsts) <- unzip . concat <$> hugSomeThingsBelowUs (\mod_info -> let details = hm_details mod_info -- Don't include instances for the current module - in if moduleName (mi_module (hm_iface mod_info)) == mn + in if fmap toUnitId (mi_module (hm_iface mod_info)) == mn then [] else [(md_insts details, md_fam_insts details)]) True -- Include -hi-boot ===================================== testsuite/tests/ghci/prog-mhu008/Makefile ===================================== @@ -0,0 +1,3 @@ +TOP=../../.. +include $(TOP)/mk/boilerplate.mk +include $(TOP)/mk/test.mk ===================================== testsuite/tests/ghci/prog-mhu008/a/M.hs ===================================== @@ -0,0 +1,4 @@ +module M (T (..)) where + +newtype T = MkT Int + deriving (Eq, Ord) ===================================== testsuite/tests/ghci/prog-mhu008/all.T ===================================== @@ -0,0 +1,5 @@ +test('prog-mhu008', + [extra_files(['a/', 'b/', 'unitA', 'unitB']), + cmd_prefix('ghciWayFlags=' + config.ghci_way_flags), + req_interp], + ghci_multiunit_script, [['unitA', 'unitB'], 'prog-mhu008.script']) ===================================== testsuite/tests/ghci/prog-mhu008/b/M.hs ===================================== @@ -0,0 +1,11 @@ +{-# LANGUAGE PackageImports #-} + +module M + ( module Export + , cmp + ) where + +import "a" M as Export + +cmp :: T -> T -> Bool +cmp x y = x <= y ===================================== testsuite/tests/ghci/prog-mhu008/prog-mhu008.script ===================================== @@ -0,0 +1,5 @@ +:set -XPackageImports +import "a" M qualified as MA +import "b" M qualified as MB + +MB.cmp (MA.MkT 1) (MA.MkT 2) ===================================== testsuite/tests/ghci/prog-mhu008/prog-mhu008.stdout ===================================== @@ -0,0 +1 @@ +True ===================================== testsuite/tests/ghci/prog-mhu008/unitA ===================================== @@ -0,0 +1,5 @@ +-this-unit-id a-0-inplace +-this-package-name a +-i +-ia +M ===================================== testsuite/tests/ghci/prog-mhu008/unitB ===================================== @@ -0,0 +1,6 @@ +-this-unit-id b-0-inplace +-this-package-name b +-package-id a-0-inplace +-i +-ib +M View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/bf17f289eb6abf929917350e6e3c549… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/bf17f289eb6abf929917350e6e3c549… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc][master] Change the C types of hs_{bitrev,bswap}{16,32} to match the Haskell types
by Marge Bot (＠marge-bot) 23 Sep '26

23 Sep '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 545fd4fb by ARATA Mizuki at 2026-09-22T15:03:24-04:00 Change the C types of hs_{bitrev,bswap}{16,32} to match the Haskell types bitReverse{16,32}# and byteSwap{16,32}# have the type Word# -> Word#, but their C correspondents took and returned StgWord{16,32}. The mismatch on bitReverse16# led to the problem reported in #27299. Although no similar issue is reported for bitReverse32# and byteSwap{16,32}#, it seemed wise to change them proactively. This commit fixes the mismatch by changing the C type. Fixes #27299 - - - - - 6 changed files: - rts/include/stg/Prim.h - rts/prim/bitrev.c - rts/prim/bswap.c - + testsuite/tests/primops/should_run/T27299.hs - + testsuite/tests/primops/should_run/T27299.stdout - testsuite/tests/primops/should_run/all.T Changes: ===================================== rts/include/stg/Prim.h ===================================== @@ -59,16 +59,16 @@ StgWord hs_xchg32(StgWord x, StgWord val); StgWord64 hs_xchg64(StgWord x, StgWord64 val); /* rts/prim/bswap.c */ -StgWord16 hs_bswap16(StgWord16 x); -StgWord32 hs_bswap32(StgWord32 x); +StgWord hs_bswap16(StgWord x); +StgWord hs_bswap32(StgWord x); StgWord64 hs_bswap64(StgWord64 x); /* rts/prim/bitrev.c This was done as part of issue #16164. See Note [Bit reversal primop] for more details about the implementation.*/ StgWord hs_bitrev8(StgWord x); -StgWord16 hs_bitrev16(StgWord16 x); -StgWord32 hs_bitrev32(StgWord32 x); +StgWord hs_bitrev16(StgWord x); +StgWord hs_bitrev32(StgWord x); StgWord64 hs_bitrev64(StgWord64 x); /* rts/prim/longlong.c */ ===================================== rts/prim/bitrev.c ===================================== @@ -36,8 +36,8 @@ hs_bitrev8(StgWord x) return x; } -StgWord16 -hs_bitrev16(StgWord16 x) +StgWord +hs_bitrev16(StgWord x) { x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1 ); x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2 ); @@ -46,14 +46,14 @@ hs_bitrev16(StgWord16 x) return x; } -StgWord32 -hs_bitrev32(StgWord32 x) +StgWord +hs_bitrev32(StgWord x) { - x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1 ); - x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2 ); - x = ((x >> 4) & 0x0F0F0F0F) | ((x & 0x0F0F0F0F) << 4 ); - x = ((x >> 8) & 0x00FF00FF) | ((x & 0x00FF00FF) << 8 ); - x = ( x >> 16 ) | ( x << 16 ); + x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1 ); + x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2 ); + x = ((x >> 4) & 0x0F0F0F0F) | ((x & 0x0F0F0F0F) << 4 ); + x = ((x >> 8) & 0x00FF00FF) | ((x & 0x00FF00FF) << 8 ); + x = ((x >> 16) & 0x0000FFFF) | ((x & 0x0000FFFF) << 16); return x; } ===================================== rts/prim/bswap.c ===================================== @@ -1,16 +1,18 @@ #include "Rts.h" -StgWord16 -hs_bswap16(StgWord16 x) +StgWord +hs_bswap16(StgWord x) { - return ((x >> 8) | (x << 8)); + x = (StgWord16)x; + return (StgWord16)((x >> 8) | (x << 8)); } -StgWord32 -hs_bswap32(StgWord32 x) +StgWord +hs_bswap32(StgWord x) { - return ((x >> 24) | ((x >> 8) & 0xff00) | - (x << 24) | ((x & 0xff00) << 8)); + x = (StgWord32)x; + return (StgWord32)((x >> 24) | ((x >> 8) & 0xff00) | + (x << 24) | ((x & 0xff00) << 8)); } StgWord64 ===================================== testsuite/tests/primops/should_run/T27299.hs ===================================== @@ -0,0 +1,23 @@ +{-# LANGUAGE MagicHash #-} +import GHC.Exts +import GHC.Word +import Numeric + +main :: IO () +main = do + putStrLn $ showHex (W# (bitReverse8# 0x55##)) "" + putStrLn $ showHex (W# (bitReverse8# 0xAA##)) "" + putStrLn $ showHex (W# (bitReverse16# 0x5555##)) "" + putStrLn $ showHex (W# (bitReverse16# 0xAAAA##)) "" + putStrLn $ showHex (W# (bitReverse32# 0x5555_5555##)) "" + putStrLn $ showHex (W# (bitReverse32# 0xAAAA_AAAA##)) "" + putStrLn $ showHex (W# (byteSwap16# 0xABCD##)) "" + putStrLn $ showHex (W# (byteSwap32# 0xABCD_EF12##)) "" + putStrLn $ showHex (W# (noinline bitReverse8# 0x55##)) "" + putStrLn $ showHex (W# (noinline bitReverse8# 0xAA##)) "" + putStrLn $ showHex (W# (noinline bitReverse16# 0x5555##)) "" + putStrLn $ showHex (W# (noinline bitReverse16# 0xAAAA##)) "" + putStrLn $ showHex (W# (noinline bitReverse32# 0x5555_5555##)) "" + putStrLn $ showHex (W# (noinline bitReverse32# 0xAAAA_AAAA##)) "" + putStrLn $ showHex (W# (noinline byteSwap16# 0xABCD##)) "" + putStrLn $ showHex (W# (noinline byteSwap32# 0xABCD_EF12##)) "" ===================================== testsuite/tests/primops/should_run/T27299.stdout ===================================== @@ -0,0 +1,16 @@ +aa +55 +aaaa +5555 +aaaaaaaa +55555555 +cdab +12efcdab +aa +55 +aaaa +5555 +aaaaaaaa +55555555 +cdab +12efcdab ===================================== testsuite/tests/primops/should_run/all.T ===================================== @@ -91,3 +91,4 @@ test('T24496' ] , compile_and_run, ['-O']) test('T6026', normal, compile_and_run, ['']) +test('T27299', normal, compile_and_run, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/545fd4fb69d7572180f13fe81e65e42… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/545fd4fb69d7572180f13fe81e65e42… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0

[Git][ghc/ghc] Pushed new branch wip/clc-proposal-442
by BinderDavid (＠BinderDavid) 23 Sep '26

23 Sep '26

BinderDavid pushed new branch wip/clc-proposal-442 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/clc-proposal-442 You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

1 0