July 2025 - ghc-commits

[Git][ghc/ghc][wip/romes/step-out-10] 4 commits: LAST PART WIP
by Rodrigo Mesquita (＠alt-romes) 02 Jul '25

02 Jul '25

Rodrigo Mesquita pushed to branch wip/romes/step-out-10 at Glasgow Haskell Compiler / GHC Commits: 058ddc61 by Rodrigo Mesquita at 2025-07-02T14:56:10+01:00 LAST PART WIP - - - - - 8837b6ba by Rodrigo Mesquita at 2025-07-02T15:00:16+01:00 A thing that I don't like - - - - - 9a35db92 by Rodrigo Mesquita at 2025-07-02T15:00:21+01:00 Revert "A thing that I don't like" This reverts commit 8837b6ba2bac987debeca39304e461417a28abb4. - - - - - 71819682 by Rodrigo Mesquita at 2025-07-02T16:48:57+01:00 Good - - - - - 13 changed files: - compiler/GHC/ByteCode/Asm.hs - compiler/GHC/ByteCode/Breakpoints.hs - compiler/GHC/ByteCode/Instr.hs - compiler/GHC/CoreToIface.hs - compiler/GHC/HsToCore/Breakpoints.hs - compiler/GHC/Runtime/Interpreter.hs - compiler/GHC/StgToByteCode.hs - libraries/ghci/GHCi/Debugger.hs - libraries/ghci/GHCi/Message.hs - libraries/ghci/GHCi/Run.hs - rts/Disassembler.c - rts/Exception.cmm - rts/Interpreter.c Changes: ===================================== compiler/GHC/ByteCode/Asm.hs ===================================== @@ -841,24 +841,19 @@ assembleI platform i = case i of W8 -> emit_ bci_OP_INDEX_ADDR_08 [] _ -> unsupported_width - BRK_FUN (InternalBreakpointId tick_mod tickx info_mod infox) -> do + BRK_FUN ibi@(InternalBreakpointId info_mod infox) -> do + p1 <- ptr $ BCOPtrBreakArray info_mod let -- cast that checks that round-tripping through Word16 doesn't change the value toW16 x = let r = fromIntegral x :: Word16 in if fromIntegral r == x then r else pprPanic "schemeER_wrk: breakpoint tick/info index too large!" (ppr x) - p1 <- ptr $ BCOPtrBreakArray tick_mod tick_addr <- lit1 $ BCONPtrFS $ moduleNameFS $ moduleName tick_mod info_addr <- lit1 $ BCONPtrFS $ moduleNameFS $ moduleName info_mod - tick_unitid_addr <- lit1 $ BCONPtrFS $ unitIdFS $ moduleUnitId $ tick_mod - info_unitid_addr <- lit1 $ BCONPtrFS $ unitIdFS $ moduleUnitId $ info_mod - np <- lit1 $ BCONPtrCostCentre (BreakpointId tick_mod tickx) - emit_ bci_BRK_FUN [ Op p1 - , Op tick_addr, Op info_addr - , Op tick_unitid_addr, Op info_unitid_addr - , SmallOp (toW16 tickx), SmallOp (toW16 infox) - , Op np - ] + info_unitid_addr <- lit1 $ BCONPtrFS $ unitIdFS $ moduleUnitId info_mod + np <- lit1 $ BCONPtrCostCentre ibi + emit_ bci_BRK_FUN [ Op p1, Op info_addr, Op info_unitid_addr + , SmallOp infox, Op np ] BRK_ALTS active -> emit_ bci_BRK_ALTS [SmallOp (if active then 1 else 0)] ===================================== compiler/GHC/ByteCode/Breakpoints.hs ===================================== @@ -7,20 +7,19 @@ -- 'InternalModBreaks', and is uniquely identified at runtime by an -- 'InternalBreakpointId'. -- --- See Note [Breakpoint identifiers] +-- See Note [ModBreaks vs InternalModBreaks] and Note [Breakpoint identifiers] module GHC.ByteCode.Breakpoints ( -- * Internal Mod Breaks InternalModBreaks(..), CgBreakInfo(..) - , mkInternalModBreaks + , mkInternalModBreaks, imodBreaks_module -- ** Internal breakpoint identifier , InternalBreakpointId(..), BreakInfoIndex -- * Operations - , toBreakpointId -- ** Internal-level operations - , getInternalBreak, addInternalBreak + , getInternalBreak -- ** Source-level information operations , getBreakLoc, getBreakVars, getBreakDecls, getBreakCCS @@ -47,6 +46,31 @@ import GHC.Utils.Panic import Data.Array {- +Note [ModBreaks vs InternalModBreaks] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +'ModBreaks' and 'BreakpointId's must not to be confused with +'InternalModBreaks' and 'InternalBreakId's. + +'ModBreaks' is constructed once during HsToCore from the information attached +to source-level breakpoint ticks and is never changed afterwards. A 'ModBreaks' +can be queried using 'BreakpointId's, which uniquely identifies a breakpoint +within the list of breakpoint information for a given module's 'ModBreaks'. + +'InternalModBreaks' are constructed during bytecode generation and are indexed +by a 'InternalBreakpointId'. They contain all the information relevant to a +breakpoint for code generation that can be accessed during runtime execution +(such as a 'BreakArray' for triggering breakpoints). 'InternalBreakpointId's +are used at runtime to trigger and inspect breakpoints -- a 'BRK_FUN' +instruction receives 'InternalBreakpointId' as an argument. + +We keep a mapping from 'InternalModBreaks' to a 'BreakpointId', which can then be used +to get source-level information about a breakpoint via the corresponding 'ModBreaks'. + +Notably, 'InternalModBreaks' can contain entries for so-called internal +breakpoints, which do not necessarily have a source-level location attached to +it (i.e. do not have a matching entry in 'ModBreaks'). We may leverage this to +introduce breakpoints during code generation for features such as stepping-out. + Note [Breakpoint identifiers] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Before optimization a breakpoint is identified uniquely with a tick module @@ -64,6 +88,10 @@ So every breakpoint occurrence gets assigned a module-unique *info index* and we store it alongside the occurrence module (*info module*) in the 'InternalBreakpointId' datatype. This is the index that we use at runtime to identify a breakpoint. + +When the internal breakpoint has a matching tick-level breakpoint we can fetch +the related tick-level information by first looking up a mapping +@'InternalBreakpointId' -> 'BreakpointId'@ in @'CgBreakInfo'@. -} -------------------------------------------------------------------------------- @@ -78,19 +106,11 @@ type BreakInfoIndex = Int -- Indexes into the structures in the @'InternalModBreaks'@ produced during ByteCode generation. -- See Note [Breakpoint identifiers] data InternalBreakpointId = InternalBreakpointId - { ibi_tick_mod :: !Module -- ^ Breakpoint tick module - , ibi_tick_index :: !Int -- ^ Breakpoint tick index - , ibi_info_mod :: !Module -- ^ Breakpoint tick module + { ibi_info_mod :: !Module -- ^ Breakpoint tick module , ibi_info_index :: !BreakInfoIndex -- ^ Breakpoint tick index } deriving (Eq, Ord) -toBreakpointId :: InternalBreakpointId -> BreakpointId -toBreakpointId ibi = BreakpointId - { bi_tick_mod = ibi_tick_mod ibi - , bi_tick_index = ibi_tick_index ibi - } - -------------------------------------------------------------------------------- -- * Internal Mod Breaks -------------------------------------------------------------------------------- @@ -107,18 +127,34 @@ data InternalModBreaks = InternalModBreaks -- 'InternalBreakpointId'. , imodBreaks_modBreaks :: !ModBreaks - -- ^ Store the original ModBreaks for this module, unchanged. - -- Allows us to query about source-level breakpoint information using - -- an internal breakpoint id. + -- ^ Store the ModBreaks for this module + -- + -- Recall Note [Breakpoint identifiers]: for some module A, an + -- *occurrence* of a breakpoint in A may have been inlined from some + -- breakpoint *defined* in module B. + -- + -- This 'ModBreaks' contains information regarding all the breakpoints + -- defined in the module this 'InternalModBreaks' corresponds to. It + -- /does not/ necessarily have information regarding all the breakpoint + -- occurrences registered in 'imodBreaks_breakInfo'. Some of those + -- occurrences may refer breakpoints inlined from other modules. } --- | Construct an 'InternalModBreaks' +-- | Construct an 'InternalModBreaks'. +-- +-- INVARIANT: The given 'ModBreaks' correspond to the same module as this +-- 'InternalModBreaks' module (the first argument) and its breakpoint infos +-- (the @IntMap CgBreakInfo@ argument) mkInternalModBreaks :: Module -> IntMap CgBreakInfo -> ModBreaks -> InternalModBreaks mkInternalModBreaks mod im mbs = assertPpr (mod == modBreaks_module mbs) (text "Constructing InternalModBreaks with the ModBreaks of a different module!") $ InternalModBreaks im mbs +-- | Get the module to which these 'InternalModBreaks' correspond +imodBreaks_module :: InternalModBreaks -> Module +imodBreaks_module = modBreaks_module . imodBreaks_modBreaks + -- | Information about a breakpoint that we know at code-generation time -- In order to be used, this needs to be hydrated relative to the current HscEnv by -- 'hydrateCgBreakInfo'. Everything here can be fully forced and that's critical for @@ -128,20 +164,22 @@ data CgBreakInfo { cgb_tyvars :: ![IfaceTvBndr] -- ^ Type variables in scope at the breakpoint , cgb_vars :: ![Maybe (IfaceIdBndr, Word)] , cgb_resty :: !IfaceType + , cgb_tick_id :: !BreakpointId + -- ^ This field records the original breakpoint tick identifier for this + -- internal breakpoint info. It is used to convert a breakpoint + -- *occurrence* index ('InternalBreakpointId') into a *definition* index + -- ('BreakpointId'). + -- + -- The modules of breakpoint occurrence and breakpoint definition are not + -- necessarily the same: See Note [Breakpoint identifiers]. } -- See Note [Syncing breakpoint info] in GHC.Runtime.Eval -- | Get an internal breakpoint info by 'InternalBreakpointId' getInternalBreak :: InternalBreakpointId -> InternalModBreaks -> CgBreakInfo -getInternalBreak (InternalBreakpointId _ _ info_mod info_ix) imbs = - assert_modules_match info_mod (modBreaks_module $ imodBreaks_modBreaks imbs) $ - imodBreaks_breakInfo imbs IM.! info_ix - --- | Add a CgBreakInfo to an 'InternalModBreaks' at 'InternalBreakpointId' -addInternalBreak :: InternalBreakpointId -> CgBreakInfo -> InternalModBreaks -> InternalModBreaks -addInternalBreak (InternalBreakpointId _ _ info_mod info_ix) info imbs = - assert_modules_match info_mod (modBreaks_module $ imodBreaks_modBreaks imbs) $ - imbs{imodBreaks_breakInfo = IM.insert info_ix info (imodBreaks_breakInfo imbs)} +getInternalBreak (InternalBreakpointId mod ix) imbs = + assert_modules_match mod (imodBreaks_module imbs) $ + imodBreaks_breakInfo imbs IM.! ix -- | Assert that the module in the 'InternalBreakpointId' and in -- 'InternalModBreaks' match. @@ -156,26 +194,47 @@ assert_modules_match ibi_mod imbs_mod = -------------------------------------------------------------------------------- -- | Get the source span for this breakpoint -getBreakLoc :: InternalBreakpointId -> InternalModBreaks -> SrcSpan +getBreakLoc :: (Module -> IO ModBreaks) -> InternalBreakpointId -> InternalModBreaks -> IO SrcSpan getBreakLoc = getBreakXXX modBreaks_locs -- | Get the vars for this breakpoint -getBreakVars :: InternalBreakpointId -> InternalModBreaks -> [OccName] +getBreakVars :: (Module -> IO ModBreaks) -> InternalBreakpointId -> InternalModBreaks -> IO [OccName] getBreakVars = getBreakXXX modBreaks_vars -- | Get the decls for this breakpoint -getBreakDecls :: InternalBreakpointId -> InternalModBreaks -> [String] +getBreakDecls :: (Module -> IO ModBreaks) -> InternalBreakpointId -> InternalModBreaks -> IO [String] getBreakDecls = getBreakXXX modBreaks_decls -- | Get the decls for this breakpoint -getBreakCCS :: InternalBreakpointId -> InternalModBreaks -> (String, String) +getBreakCCS :: (Module -> IO ModBreaks) -> InternalBreakpointId -> InternalModBreaks -> IO (String, String) getBreakCCS = getBreakXXX modBreaks_ccs -- | Internal utility to access a ModBreaks field at a particular breakpoint index -getBreakXXX :: (ModBreaks -> Array BreakTickIndex a) -> InternalBreakpointId -> InternalModBreaks -> a -getBreakXXX view (InternalBreakpointId tick_mod tick_id _ _) imbs = - assert_modules_match tick_mod (modBreaks_module $ imodBreaks_modBreaks imbs) $ do - view (imodBreaks_modBreaks imbs) ! tick_id +-- +-- Recall Note [Breakpoint identifiers]: the internal breakpoint module (the +-- *occurrence* module) doesn't necessarily match the module where the +-- tick breakpoint was defined with the relevant 'ModBreaks'. +-- +-- When the tick module is the same as the internal module, we use the stored +-- 'ModBreaks'. When the tick module is different, we need to look up the +-- 'ModBreaks' in the HUG for that other module. +-- +-- To avoid cyclic dependencies, we instead receive a function that looks up +-- the 'ModBreaks' given a 'Module' +getBreakXXX :: (ModBreaks -> Array BreakTickIndex a) -> (Module -> IO ModBreaks) -> InternalBreakpointId -> InternalModBreaks -> IO a +getBreakXXX view lookupModule (InternalBreakpointId ibi_mod ibi_ix) imbs = + assert_modules_match ibi_mod (imodBreaks_module imbs) $ do + let cgb = imodBreaks_breakInfo imbs IM.! ibi_ix + case cgb_tick_id cgb of + BreakpointId{bi_tick_mod, bi_tick_index} + | bi_tick_mod == ibi_mod + -> do + let these_mbs = imodBreaks_modBreaks imbs + return $ view these_mbs ! bi_tick_index + | otherwise + -> do + other_mbs <- lookupModule bi_tick_mod + return $ view other_mbs ! bi_tick_index -------------------------------------------------------------------------------- -- Instances @@ -190,7 +249,8 @@ seqInternalModBreaks InternalModBreaks{..} = seqCgBreakInfo CgBreakInfo{..} = rnf cgb_tyvars `seq` rnf cgb_vars `seq` - rnf cgb_resty + rnf cgb_resty `seq` + rnf cgb_tick_id instance Outputable InternalBreakpointId where ppr InternalBreakpointId{..} = @@ -203,4 +263,5 @@ instance NFData InternalBreakpointId where instance Outputable CgBreakInfo where ppr info = text "CgBreakInfo" <+> parens (ppr (cgb_vars info) <+> - ppr (cgb_resty info)) + ppr (cgb_resty info) <+> + ppr (cgb_tick_id info)) ===================================== compiler/GHC/ByteCode/Instr.hs ===================================== @@ -454,9 +454,8 @@ instance Outputable BCInstr where ppr ENTER = text "ENTER" ppr (RETURN pk) = text "RETURN " <+> ppr pk ppr (RETURN_TUPLE) = text "RETURN_TUPLE" - ppr (BRK_FUN (InternalBreakpointId tick_mod tickx info_mod infox)) + ppr (BRK_FUN (InternalBreakpointId info_mod infox)) = text "BRK_FUN" <+> text "<breakarray>" - <+> ppr tick_mod <+> ppr tickx <+> ppr info_mod <+> ppr infox <+> text "<cc>" ppr (BRK_ALTS active) = text "BRK_ALTS" <+> ppr active ===================================== compiler/GHC/CoreToIface.hs ===================================== @@ -704,12 +704,13 @@ toIfaceLFInfo nm lfi = case lfi of -- Dehydrating CgBreakInfo -dehydrateCgBreakInfo :: [TyVar] -> [Maybe (Id, Word)] -> Type -> CgBreakInfo -dehydrateCgBreakInfo ty_vars idOffSets tick_ty = +dehydrateCgBreakInfo :: [TyVar] -> [Maybe (Id, Word)] -> Type -> BreakpointId -> CgBreakInfo +dehydrateCgBreakInfo ty_vars idOffSets tick_ty bid = CgBreakInfo { cgb_tyvars = map toIfaceTvBndr ty_vars , cgb_vars = map (fmap (\(i, offset) -> (toIfaceIdBndr i, offset))) idOffSets , cgb_resty = toIfaceType tick_ty + , cgb_tick_id = bid } {- Note [Inlining and hs-boot files] ===================================== compiler/GHC/HsToCore/Breakpoints.hs ===================================== @@ -12,7 +12,7 @@ -- 'InternalModBreaks' and 'InternalBreakId's. The latter are constructed -- during bytecode generation and can be found in 'GHC.ByteCode.Breakpoints'. -- --- See Note [Breakpoint identifiers] +-- See Note [ModBreaks vs InternalModBreaks] and Note [Breakpoint identifiers] module GHC.HsToCore.Breakpoints ( -- * ModBreaks mkModBreaks, ModBreaks(..) ===================================== compiler/GHC/Runtime/Interpreter.hs ===================================== @@ -28,6 +28,7 @@ module GHC.Runtime.Interpreter , whereFrom , getModBreaks , readModBreaks + , readModBreaksMaybe , seqHValue , evalBreakpointToId @@ -411,15 +412,10 @@ evalBreakpointToId :: EvalBreakpoint -> InternalBreakpointId evalBreakpointToId eval_break = let mkUnitId u = fsToUnit $ mkFastStringShortByteString u - toModule u n = mkModule (mkUnitId u) (mkModuleName n) - tickl = toModule (eb_tick_mod_unit eval_break) (eb_tick_mod eval_break) - infol = toModule (eb_info_mod_unit eval_break) (eb_info_mod eval_break) in InternalBreakpointId - { ibi_tick_mod = tickl - , ibi_tick_index = eb_tick_index eval_break - , ibi_info_mod = infol + { ibi_info_mod = toModule (eb_info_mod_unit eval_break) (eb_info_mod eval_break) , ibi_info_index = eb_info_index eval_break } @@ -440,17 +436,18 @@ handleSeqHValueStatus interp unit_env eval_status = -- Reason: Setting of flags in libraries/ghci/GHCi/Run.hs:evalOptsSeq Just break -> do - let bi = evalBreakpointToId break + let ibi = evalBreakpointToId break + hug = ue_home_unit_graph unit_env -- Just case: Stopped at a breakpoint, extract SrcSpan information -- from the breakpoint. - mb_modbreaks <- getModBreaks . expectJust <$> - lookupHugByModule (ibi_tick_mod bi) (ue_home_unit_graph unit_env) + mb_modbreaks <- readModBreaksMaybe hug (ibi_info_mod ibi) case mb_modbreaks of -- Nothing case - should not occur! We should have the appropriate -- breakpoint information Nothing -> nothing_case - Just modbreaks -> put $ brackets . ppr $ getBreakLoc bi modbreaks + Just modbreaks -> put . brackets . ppr =<< + getBreakLoc (fmap imodBreaks_modBreaks . readModBreaks hug) ibi modbreaks -- resume the seq (:force) processing in the iserv process withForeignRef resume_ctxt_fhv $ \hval -> do @@ -745,10 +742,13 @@ getModBreaks hmi | otherwise = Nothing -- probably object code --- | Read the 'InternalModBreaks' and 'ModBreaks' of the given home 'Module' --- from the 'HomeUnitGraph'. +-- | Read the 'InternalModBreaks' of the given home 'Module' from the 'HomeUnitGraph'. readModBreaks :: HomeUnitGraph -> Module -> IO InternalModBreaks -readModBreaks hug modl = expectJust . getModBreaks . expectJust <$> HUG.lookupHugByModule modl hug +readModBreaks hug modl = expectJust <$> readModBreaksMaybe hug modl + +-- | Read the 'InternalModBreaks' of the given home 'Module' from the 'HomeUnitGraph'. +readModBreaksMaybe :: HomeUnitGraph -> Module -> IO (Maybe InternalModBreaks) +readModBreaksMaybe hug modl = getModBreaks . expectJust <$> HUG.lookupHugByModule modl hug -- ----------------------------------------------------------------------------- -- Misc utils ===================================== compiler/GHC/StgToByteCode.hs ===================================== @@ -31,7 +31,6 @@ import GHC.Cmm.Utils import GHC.Platform import GHC.Platform.Profile -import GHC.Runtime.Interpreter import GHCi.FFI import GHC.Types.Basic import GHC.Utils.Outputable @@ -64,6 +63,7 @@ import GHC.StgToCmm.Closure ( NonVoid(..), fromNonVoid, idPrimRepU, assertNonVoidIds, assertNonVoidStgArgs ) import GHC.StgToCmm.Layout import GHC.Runtime.Heap.Layout hiding (WordOff, ByteOff, wordsToBytes) +import GHC.Runtime.Interpreter ( interpreterProfiled ) import GHC.Data.Bitmap import GHC.Data.FlatBag as FlatBag import GHC.Data.OrdList @@ -79,7 +79,6 @@ import Control.Monad import Data.Char import GHC.Unit.Module -import qualified GHC.Unit.Home.Graph as HUG import Data.Coerce (coerce) #if MIN_VERSION_rts(1,0,3) @@ -394,65 +393,28 @@ schemeR_wrk fvs nm original_body (args, body) -- | Introduce break instructions for ticked expressions. -- If no breakpoint information is available, the instruction is omitted. schemeER_wrk :: StackDepth -> BCEnv -> CgStgExpr -> BcM BCInstrList -schemeER_wrk d p (StgTick (Breakpoint tick_ty (BreakpointId tick_mod tick_no) fvs) rhs) = do +schemeER_wrk d p (StgTick (Breakpoint tick_ty tick_id fvs) rhs) = do code <- schemeE d 0 p rhs - hsc_env <- getHscEnv - current_mod <- getCurrentModule mb_current_mod_breaks <- getCurrentModBreaks case mb_current_mod_breaks of -- if we're not generating ModBreaks for this module for some reason, we -- can't store breakpoint occurrence information. Nothing -> pure code - Just current_mod_breaks -> break_info hsc_env tick_mod current_mod mb_current_mod_breaks >>= \case - Nothing -> pure code - Just ModBreaks{modBreaks_module = tick_mod} -> do - platform <- profilePlatform <$> getProfile - let idOffSets = getVarOffSets platform d p fvs - ty_vars = tyCoVarsOfTypesWellScoped (tick_ty:map idType fvs) - toWord :: Maybe (Id, WordOff) -> Maybe (Id, Word) - toWord = fmap (\(i, wo) -> (i, fromIntegral wo)) - breakInfo = dehydrateCgBreakInfo ty_vars (map toWord idOffSets) tick_ty + Just current_mod_breaks -> do + platform <- profilePlatform <$> getProfile + let idOffSets = getVarOffSets platform d p fvs + ty_vars = tyCoVarsOfTypesWellScoped (tick_ty:map idType fvs) + toWord :: Maybe (Id, WordOff) -> Maybe (Id, Word) + toWord = fmap (\(i, wo) -> (i, fromIntegral wo)) + breakInfo = dehydrateCgBreakInfo ty_vars (map toWord idOffSets) tick_ty tick_id - let info_mod = modBreaks_module current_mod_breaks - infox <- newBreakInfo breakInfo + let info_mod = modBreaks_module current_mod_breaks + infox <- newBreakInfo breakInfo - let breakInstr = BRK_FUN (InternalBreakpointId tick_mod tick_no info_mod infox) - return $ breakInstr `consOL` code + let breakInstr = BRK_FUN (InternalBreakpointId info_mod infox) + return $ breakInstr `consOL` code schemeER_wrk d p rhs = schemeE d 0 p rhs --- | Determine the GHCi-allocated 'BreakArray' and module pointer for the module --- from which the breakpoint originates. --- These are stored in 'ModBreaks' as remote pointers in order to allow the BCOs --- to refer to pointers in GHCi's address space. --- They are initialized in 'GHC.HsToCore.Breakpoints.mkModBreaks', called by --- 'GHC.HsToCore.deSugar'. --- --- Breakpoints might be disabled because we're in TH, because --- @-fno-break-points@ was specified, or because a module was reloaded without --- reinitializing 'ModBreaks'. --- --- If the module stored in the breakpoint is the currently processed module, use --- the 'ModBreaks' from the state. --- If that is 'Nothing', consider breakpoints to be disabled and skip the --- instruction. --- --- If the breakpoint is inlined from another module, look it up in the HUG (home unit graph). --- If the module doesn't exist there, or if the 'ModBreaks' value is --- uninitialized, skip the instruction (i.e. return Nothing). -break_info :: - HscEnv -> - Module -> - Module -> - Maybe ModBreaks -> - BcM (Maybe ModBreaks) -break_info hsc_env mod current_mod current_mod_breaks - | mod == current_mod - = pure current_mod_breaks - | otherwise - = liftIO (HUG.lookupHugByModule mod (hsc_HUG hsc_env)) >>= \case - Just hp -> pure $ imodBreaks_modBreaks <$> getModBreaks hp - Nothing -> pure Nothing - getVarOffSets :: Platform -> StackDepth -> BCEnv -> [Id] -> [Maybe (Id, WordOff)] getVarOffSets platform depth env = map getOffSet where ===================================== libraries/ghci/GHCi/Debugger.hs ===================================== @@ -65,10 +65,7 @@ foreign import ccall "&rts_stop_on_exception" exceptionFlag :: Ptr CInt -------------------------------------------------------------------------------- type BreakpointCallback - = Addr# -- pointer to the breakpoint tick module name - -> Addr# -- pointer to the breakpoint tick module unit id - -> Int# -- breakpoint tick index - -> Addr# -- pointer to the breakpoint info module name + = Addr# -- pointer to the breakpoint info module name -> Addr# -- pointer to the breakpoint info module unit id -> Int# -- breakpoint info index -> Bool -- exception? ===================================== libraries/ghci/GHCi/Message.hs ===================================== @@ -418,10 +418,7 @@ data EvalStatus_ a b instance Binary a => Binary (EvalStatus_ a b) data EvalBreakpoint = EvalBreakpoint - { eb_tick_mod :: String -- ^ Breakpoint tick module - , eb_tick_mod_unit :: BS.ShortByteString -- ^ Breakpoint tick module unit id - , eb_tick_index :: Int -- ^ Breakpoint tick index - , eb_info_mod :: String -- ^ Breakpoint info module + { eb_info_mod :: String -- ^ Breakpoint info module , eb_info_mod_unit :: BS.ShortByteString -- ^ Breakpoint tick module unit id , eb_info_index :: Int -- ^ Breakpoint info index } ===================================== libraries/ghci/GHCi/Run.hs ===================================== @@ -345,7 +345,7 @@ withBreakAction opts breakMVar statusMVar mtid act -- as soon as it is hit, or in resetBreakAction below. onBreak :: BreakpointCallback - onBreak tick_mod# tick_mod_uid# tickx# info_mod# info_mod_uid# infox# is_exception apStack = do + onBreak info_mod# info_mod_uid# infox# is_exception apStack = do tid <- myThreadId let resume = ResumeContext { resumeBreakMVar = breakMVar @@ -358,11 +358,9 @@ withBreakAction opts breakMVar statusMVar mtid act if is_exception then pure Nothing else do - tick_mod <- peekCString (Ptr tick_mod#) - tick_mod_uid <- BS.packCString (Ptr tick_mod_uid#) info_mod <- peekCString (Ptr info_mod#) info_mod_uid <- BS.packCString (Ptr info_mod_uid#) - pure (Just (EvalBreakpoint tick_mod tick_mod_uid (I# tickx#) info_mod info_mod_uid (I# infox#))) + pure (Just (EvalBreakpoint info_mod info_mod_uid (I# infox#))) putMVar statusMVar $ EvalBreak apStack_r breakpoint resume_r ccs takeMVar breakMVar @@ -409,8 +407,8 @@ noBreakStablePtr :: StablePtr BreakpointCallback noBreakStablePtr = unsafePerformIO $ newStablePtr noBreakAction noBreakAction :: BreakpointCallback -noBreakAction _ _ _ _ _ _ False _ = putStrLn "*** Ignoring breakpoint" -noBreakAction _ _ _ _ _ _ True _ = return () -- exception: just continue +noBreakAction _ _ _ False _ = putStrLn "*** Ignoring breakpoint" +noBreakAction _ _ _ True _ = return () -- exception: just continue -- Malloc and copy the bytes. We don't have any way to monitor the -- lifetime of this memory, so it just leaks. ===================================== rts/Disassembler.c ===================================== @@ -84,16 +84,23 @@ disInstr ( StgBCO *bco, int pc ) switch (instr & 0xff) { - case bci_BRK_FUN: - debugBelch ("BRK_FUN " ); printPtr( ptrs[instrs[pc]] ); - debugBelch (" %d ", instrs[pc+1]); printPtr( ptrs[instrs[pc+2]] ); - CostCentre* cc = (CostCentre*)literals[instrs[pc+5]]; + case bci_BRK_FUN: { + W_ p1, info_mod, info_unit_id, info_wix, np; + p1 = BCO_GET_LARGE_ARG; + info_mod = BCO_GET_LARGE_ARG; + info_unit_id = BCO_GET_LARGE_ARG; + info_wix = BCO_NEXT; + np = BCO_GET_LARGE_ARG; + debugBelch ("BRK_FUN " ); printPtr( ptrs[p1] ); + debugBelch("%" FMT_Word, literals[info_mod] ); + debugBelch("%" FMT_Word, literals[info_unit_id] ); + debugBelch("%" FMT_Word, info_wix ); + CostCentre* cc = (CostCentre*)literals[np]; if (cc) { debugBelch(" %s", cc->label); } debugBelch("\n"); - pc += 6; - break; + break; } case bci_BRK_ALTS: debugBelch ("BRK_ALTS %d\n", BCO_NEXT); break; ===================================== rts/Exception.cmm ===================================== @@ -535,23 +535,17 @@ retry_pop_stack: // be per-thread. CInt[rts_stop_on_exception] = 0; ("ptr" ioAction) = ccall deRefStablePtr (W_[rts_breakpoint_io_action] "ptr"); - Sp = Sp - WDS(17); - Sp(16) = exception; - Sp(15) = stg_raise_ret_info; - Sp(14) = exception; - Sp(13) = ghczminternal_GHCziInternalziTypes_True_closure; // True <=> an exception - Sp(12) = stg_ap_ppv_info; - Sp(11) = 0; - Sp(10) = stg_ap_n_info; - Sp(9) = 0; - Sp(8) = stg_ap_n_info; - Sp(7) = 0; - Sp(6) = stg_ap_n_info; - Sp(5) = 0; - Sp(4) = stg_ap_n_info; - Sp(3) = 0; - Sp(2) = stg_ap_n_info; - Sp(1) = 0; + Sp = Sp - WDS(11); + Sp(10) = exception; + Sp(9) = stg_raise_ret_info; + Sp(8) = exception; + Sp(7) = ghczminternal_GHCziInternalziTypes_True_closure; // True <=> an exception + Sp(6) = stg_ap_ppv_info; + Sp(5) = 0; + Sp(4) = stg_ap_n_info; + Sp(3) = 0; + Sp(2) = stg_ap_n_info; + Sp(1) = 0; R1 = ioAction; jump RET_LBL(stg_ap_n) [R1]; } ===================================== rts/Interpreter.c ===================================== @@ -1454,9 +1454,9 @@ run_BCO: /* check for a breakpoint on the beginning of a let binding */ case bci_BRK_FUN: { - int arg1_brk_array, arg2_tick_mod, arg3_info_mod, arg4_tick_mod_id, arg5_info_mod_id, arg6_tick_index, arg7_info_index; + W_ arg1_brk_array, arg2_info_mod_name, arg3_info_mod_id, arg4_info_index; #if defined(PROFILING) - int arg8_cc; + W_ arg5_cc; #endif StgArrBytes *breakPoints; int returning_from_break, stop_next_breakpoint; @@ -1471,14 +1471,11 @@ run_BCO: int size_words; arg1_brk_array = BCO_GET_LARGE_ARG; - arg2_tick_mod = BCO_GET_LARGE_ARG; - arg3_info_mod = BCO_GET_LARGE_ARG; - arg4_tick_mod_id = BCO_GET_LARGE_ARG; - arg5_info_mod_id = BCO_GET_LARGE_ARG; - arg6_tick_index = BCO_NEXT; - arg7_info_index = BCO_NEXT; + arg2_info_mod_name = BCO_GET_LARGE_ARG; + arg3_info_mod_id = BCO_GET_LARGE_ARG; + arg4_info_index = BCO_NEXT; #if defined(PROFILING) - arg8_cc = BCO_GET_LARGE_ARG; + arg5_cc = BCO_GET_LARGE_ARG; #else BCO_GET_LARGE_ARG; #endif @@ -1498,7 +1495,7 @@ run_BCO: #if defined(PROFILING) cap->r.rCCCS = pushCostCentre(cap->r.rCCCS, - (CostCentre*)BCO_LIT(arg8_cc)); + (CostCentre*)BCO_LIT(arg5_cc)); #endif // if we are returning from a break then skip this section @@ -1509,11 +1506,11 @@ run_BCO: // stop the current thread if either `stop_next_breakpoint` is // true OR if the ignore count for this particular breakpoint is zero - StgInt ignore_count = ((StgInt*)breakPoints->payload)[arg6_tick_index]; + StgInt ignore_count = ((StgInt*)breakPoints->payload)[arg4_info_index]; if (stop_next_breakpoint == false && ignore_count > 0) { // decrement and write back ignore count - ((StgInt*)breakPoints->payload)[arg6_tick_index] = --ignore_count; + ((StgInt*)breakPoints->payload)[arg4_info_index] = --ignore_count; } else if (stop_next_breakpoint == true || ignore_count == 0) { @@ -1547,10 +1544,7 @@ run_BCO: // Arrange the stack to call the breakpoint IO action, and // continue execution of this BCO when the IO action returns. // - // ioAction :: Addr# -- the breakpoint tick module - // -> Addr# -- the breakpoint tick module unit id - // -> Int# -- the breakpoint tick index - // -> Addr# -- the breakpoint info module + // ioAction :: Addr# -- the breakpoint info module // -> Addr# -- the breakpoint info module unit id // -> Int# -- the breakpoint info index // -> Bool -- exception? @@ -1560,23 +1554,17 @@ run_BCO: ioAction = (StgClosure *) deRefStablePtr ( rts_breakpoint_io_action); - Sp_subW(19); - SpW(18) = (W_)obj; - SpW(17) = (W_)&stg_apply_interp_info; - SpW(16) = (W_)new_aps; - SpW(15) = (W_)False_closure; // True <=> an exception - SpW(14) = (W_)&stg_ap_ppv_info; - SpW(13) = (W_)arg7_info_index; - SpW(12) = (W_)&stg_ap_n_info; - SpW(11) = (W_)BCO_LIT(arg5_info_mod_id); - SpW(10) = (W_)&stg_ap_n_info; - SpW(9) = (W_)BCO_LIT(arg3_info_mod); - SpW(8) = (W_)&stg_ap_n_info; - SpW(7) = (W_)arg6_tick_index; + Sp_subW(13); + SpW(12) = (W_)obj; + SpW(11) = (W_)&stg_apply_interp_info; + SpW(10) = (W_)new_aps; + SpW(9) = (W_)False_closure; // True <=> an exception + SpW(8) = (W_)&stg_ap_ppv_info; + SpW(7) = (W_)arg4_info_index; SpW(6) = (W_)&stg_ap_n_info; - SpW(5) = (W_)BCO_LIT(arg4_tick_mod_id); + SpW(5) = (W_)BCO_LIT(arg3_info_mod_id); SpW(4) = (W_)&stg_ap_n_info; - SpW(3) = (W_)BCO_LIT(arg2_tick_mod); + SpW(3) = (W_)BCO_LIT(arg2_info_mod_name); SpW(2) = (W_)&stg_ap_n_info; SpW(1) = (W_)ioAction; SpW(0) = (W_)&stg_enter_info; View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/58798b6431b91e1dee5a03dc3b63b6… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/58798b6431b91e1dee5a03dc3b63b6… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/T23109] Fix inlineBoringOk
by Simon Peyton Jones (＠simonpj) 02 Jul '25

02 Jul '25

Simon Peyton Jones pushed to branch wip/T23109 at Glasgow Haskell Compiler / GHC Commits: 2c0b59c5 by Simon Peyton Jones at 2025-07-02T16:32:44+01:00 Fix inlineBoringOk See (IB6) in Note [inlineBoringOk] This appears to solve the slowdown in `countdownEffectfulDynLocal` in the `effectful` library. - - - - - 3 changed files: - compiler/GHC/Core/TyCon.hs - compiler/GHC/Core/Unfold.hs - compiler/GHC/CoreToStg.hs Changes: ===================================== compiler/GHC/Core/TyCon.hs ===================================== @@ -1506,6 +1506,10 @@ There are a number of wrinkles guide inlining) treats (MkUC e) as the same size as `e`, and similarly (op d). + - `GHC.Core.Unfold.inlineBoringOK` where we want to ensure that we + always-inline (MkUC op), even into a boring context. See (IB6) + in Note [inlineBoringOk] + (UCM5) `GHC.Core.Unfold.Make.mkDFunUnfolding` builds a `DFunUnfolding` for non-unary classes, but just an /ordinary/ unfolding for unary classes. instance Num a => Num [a] where { .. } -- (I1) ===================================== compiler/GHC/Core/Unfold.hs ===================================== @@ -278,6 +278,14 @@ inlining a saturated call is no bigger than `body`. Some wrinkles: whose body is, in some sense, just as small as (g x y z). But `inlineBoringOk` doesn't attempt anything fancy; it just looks for a function call with trivial arguments, Keep it simple. + +(IB6) If we have an unfolding (K op) where K is a unary-class data constructor, + we want to inline it! So that we get calls (f op), which in turn can see (in + STG land) that `op` is already evaluated and properly tagged. (If `op` isn't + trivial we will have baled out before we get to the Var case.) This made + a big difference in benchmarks for the `effectful` library; details in !10479. + + See Note [Unary class magic] in GHC/Core/TyCon. -} inlineBoringOk :: CoreExpr -> Bool @@ -291,6 +299,7 @@ inlineBoringOk e is_fun = isValFun e go :: Int -> CoreExpr -> Bool + -- credit = #(value lambdas) = #(value args) go credit (Lam x e) | isRuntimeVar x = go (credit+1) e | otherwise = go credit e -- See (IB3) @@ -309,13 +318,15 @@ inlineBoringOk e go credit (Tick _ e) = go credit e -- dubious go credit (Cast e _) = go credit e -- See (IB3) + -- Lit: we assume credit >= 0; literals aren't functions go _ (Lit l) = litIsTrivial l && boringCxtOk - -- We assume credit >= 0; literals aren't functions go credit (Var v) | isDataConWorkId v, is_fun = boringCxtOk -- See (IB2) + | isUnaryClassId v = boringCxtOk -- See (IB6) | credit >= 0 = boringCxtOk | otherwise = boringCxtNotOk - go _ _ = boringCxtNotOk + + go _ _ = boringCxtNotOk isValFun :: CoreExpr -> Bool -- True of functions with at least ===================================== compiler/GHC/CoreToStg.hs ===================================== @@ -836,19 +836,20 @@ myCollectArgs expr res_ty where go h@(Var f) as ts | isUnaryClassId f, (the_arg:as') <- dropWhile isTypeArg as - = go the_arg as' ts + = go the_arg as' ts -- See (UCM1) in Note [Unary class magic] in GHC.Core.TyCon -- isUnaryClassId includes both the class op and the data-con - | otherwise = (h, as, ts) - go (App f a) as ts = go f (a:as) ts - go (Cast e _) as ts = go e as ts + | otherwise + = (h, as, ts) - go (Tick t e) as ts = assertPpr (not (tickishIsCode t) || all isTypeArg as) - (ppr e $$ ppr as $$ ppr ts) $ - -- See Note [Ticks in applications] - -- ticks can appear in type apps - go e as (coreToStgTick res_ty t : ts) + go (App f a) as ts = go f (a:as) ts + go (Cast e _) as ts = go e as ts + go (Tick t e) as ts = assertPpr (not (tickishIsCode t) || all isTypeArg as) + (ppr e $$ ppr as $$ ppr ts) $ + -- See Note [Ticks in applications] + -- ticks can appear in type apps + go e as (coreToStgTick res_ty t : ts) go (Case e b _ alts) as ts -- Just like in exprIsTrivial! -- Otherwise we fall over in case we encounter @@ -859,10 +860,11 @@ myCollectArgs expr res_ty | Just rhs <- isUnsafeEqualityCase e b alts = go rhs as ts -- Discards unsafeCoerce in App heads - go (Lam b e) as ts - | isTyVar b = go e (drop 1 as) ts -- Note [Collect args] + go (Lam b e) as ts + | isTyVar b + = go e (drop 1 as) ts -- Note [Collect args] - go e as ts = (e, as, ts) + go e as ts = (e, as, ts) {- Note [Collect args] ~~~~~~~~~~~~~~~~~~~~~~ View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/2c0b59c57c4c28abcf62b838e56870d… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/2c0b59c57c4c28abcf62b838e56870d… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc] Pushed new branch wip/sol-master-patch-67986
by Simon Hengel (＠sol) 02 Jul '25

02 Jul '25

Simon Hengel pushed new branch wip/sol-master-patch-67986 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/sol-master-patch-67986 You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/soulomoon/T26154-work-around] Fix crash in family instance consistency checking
by Patrick (＠soulomoon) 02 Jul '25

02 Jul '25

Patrick pushed to branch wip/soulomoon/T26154-work-around at Glasgow Haskell Compiler / GHC Commits: 04ed1efa by soulomoon at 2025-07-02T22:12:15+08:00 Fix crash in family instance consistency checking Modules from ModIface Dependencies and home package family instance environment (built from module graph) are not always consistent. Use empty family instance environment when module is not found instead of crashing during checkFamInstConsistency. Fix #26154 - - - - - 1 changed file: - compiler/GHC/Tc/Instance/Family.hs Changes: ===================================== compiler/GHC/Tc/Instance/Family.hs ===================================== @@ -405,7 +405,13 @@ getFamInsts hpt_fam_insts mod | Just env <- lookupModuleEnv hpt_fam_insts mod = return env | otherwise = do { _ <- initIfaceTcRn (loadSysInterface doc mod) ; eps <- getEps - ; return (expectJust $ + -- Workaround for #26154: + -- We use `fromMaybe emptyFamInstEnv` instead of `expectJust` because + -- the module `mod` comes from the `ModIface`'s `Dependencies`, while + -- `hpt_fam_insts` is built from `moduleGraphModulesBelow`. + -- Due to inconsistencies between the two, `mod` might not be present + -- in `hpt_fam_insts`. + ; return (fromMaybe emptyFamInstEnv $ lookupModuleEnv (eps_mod_fam_inst_env eps) mod) } where doc = ppr mod <+> text "is a family-instance module" View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/04ed1efa2e63a698b143f0c26a5b36f… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/04ed1efa2e63a698b143f0c26a5b36f… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc] Pushed new branch wip/soulomoon/T26154-work-around
by Patrick (＠soulomoon) 02 Jul '25

02 Jul '25

Patrick pushed new branch wip/soulomoon/T26154-work-around at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/soulomoon/T26154-work-around You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/bump-win32-tarballs] ghc-internal: Add dependency on compiler-rt
by Ben Gamari (＠bgamari) 02 Jul '25

02 Jul '25

Ben Gamari pushed to branch wip/bump-win32-tarballs at Glasgow Haskell Compiler / GHC Commits: 580e5051 by Ben Gamari at 2025-07-02T13:02:46+00:00 ghc-internal: Add dependency on compiler-rt This is necessary to ensure that we have - - - - - 1 changed file: - libraries/ghc-internal/ghc-internal.cabal.in Changes: ===================================== libraries/ghc-internal/ghc-internal.cabal.in ===================================== @@ -478,6 +478,8 @@ Library -- is no longer re-exporting them (see #11223) -- ucrt: standard C library. The RTS will automatically include this, -- but is added for completeness. + -- compiler-rt: this ensures that __stack_chk_fail is not resolved to + the variant provided by mingwex below. -- mingwex: provides GNU POSIX extensions that aren't provided by ucrt. -- mingw32: Unfortunately required because of a resource leak between -- mingwex and mingw32. the __math_err symbol is defined in @@ -493,7 +495,7 @@ Library -- on Windows. Required because of mingw32. extra-libraries: wsock32, user32, shell32, mingw32, kernel32, advapi32, - mingwex, ws2_32, shlwapi, ole32, rpcrt4, ntdll, ucrt + compiler-rt, mingwex, ws2_32, shlwapi, ole32, rpcrt4, ntdll, ucrt -- Minimum supported Windows version. -- These numbers can be found at: -- https://msdn.microsoft.com/en-us/library/windows/desktop/aa383745(v=vs.85).… View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/580e5051803f1a14c7d0d903dd0c48f… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/580e5051803f1a14c7d0d903dd0c48f… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/24093] fetch_gitlab: Ensure we copy users_guide.pdf and Haddock.pdf to the release docs directory
by Zubin (＠wz1000) 02 Jul '25

02 Jul '25

Zubin pushed to branch wip/24093 at Glasgow Haskell Compiler / GHC Commits: 48cf32db by Zubin Duggal at 2025-07-02T18:25:57+05:30 fetch_gitlab: Ensure we copy users_guide.pdf and Haddock.pdf to the release docs directory Fixes #24093 - - - - - 1 changed file: - .gitlab/rel_eng/fetch-gitlab-artifacts/fetch_gitlab.py Changes: ===================================== .gitlab/rel_eng/fetch-gitlab-artifacts/fetch_gitlab.py ===================================== @@ -134,6 +134,9 @@ def fetch_artifacts(release: str, pipeline_id: int, logging.info(f'extracted docs {f} to {dest}') index_path = destdir / 'docs' / 'index.html' index_path.replace(dest / 'index.html') + pdfs = list(destdir.glob('*.pdf')) + for f in pdfs: + f.replace(dest / f.name) elif job.name == 'hackage-doc-tarball': dest = dest_dir / 'hackage_docs' logging.info(f'moved hackage_docs to {dest}') View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/48cf32dbd2cf52e1db7ee68bc79a551… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/48cf32dbd2cf52e1db7ee68bc79a551… You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc] Pushed new branch wip/24093
by Zubin (＠wz1000) 02 Jul '25

02 Jul '25

Zubin pushed new branch wip/24093 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/24093 You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc] Pushed new branch wip/sand-witch/make-set-field
by Andrei Borzenkov (＠sand-witch) 02 Jul '25

02 Jul '25

Andrei Borzenkov pushed new branch wip/sand-witch/make-set-field at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/sand-witch/make-set-field You're receiving this email because of your account on gitlab.haskell.org.

1 0

[Git][ghc/ghc][wip/T26151] rts/posix: Hold on to low reservations when reserving heap
by Ben Gamari (＠bgamari) 02 Jul '25

02 Jul '25

Ben Gamari pushed to branch wip/T26151 at Glasgow Haskell Compiler / GHC Commits: d1d1abcd by Ben Gamari at 2025-07-02T08:49:22-04:00 rts/posix: Hold on to low reservations when reserving heap Previously when the OS gave us an address space reservation in low memory we would immediately release it and try again. However, on some platforms this meant that we would get the same allocation again in the next iteration (since mmap's `hint` argument is just that, a hint). Instead we now hold on to low reservations until we have found a suitable heap reservation. Fixes #26151. - - - - - 1 changed file: - rts/posix/OSMem.c Changes: ===================================== rts/posix/OSMem.c ===================================== @@ -585,6 +585,12 @@ void *osReserveHeapMemory(void *startAddressPtr, W_ *len) } #endif + const int MAX_ATTEMPTS = 8; + void *bad_allocs[MAX_ATTEMPTS]; + size_t bad_alloc_lens[MAX_ATTEMPTS]; + memset(bad_allocs, 0, sizeof(void*) * MAX_ATTEMPTS); + memset(bad_alloc_lens, 0, sizeof(size_t) * MAX_ATTEMPTS); + attempt = 0; while (attempt < MAX_ATTEMPTS) { *len &= ~MBLOCK_MASK; @@ -611,18 +617,31 @@ void *osReserveHeapMemory(void *startAddressPtr, W_ *len) } else if ((W_)at >= minimumAddress) { // Success! We were given a block of memory starting above the 8 GB // mark, which is what we were looking for. - break; } else { // We got addressing space but it wasn't above the 8GB mark. - // Try again. - if (munmap(at, *len) < 0) { - sysErrorBelch("unable to release reserved heap"); + // Free any portion *above* 8GB and hang on to the rest to increase + // the likelihood that we get a suitable allocation next iteration. + uintptr_t end = (W_) at + *len; + bad_allocs[attempt] = at; + if (end > minimumAddress) { + if (munmap((void *) minimumAddress, end - minimumAddress) < 0) { + sysErrorBelch("unable to release high portion of low memory reservation"); + } + bad_alloc_lens[attempt] = minimumAddress - (W_) at; + } else { + bad_alloc_lens[attempt] = *len; } } attempt++; } + for (int i=0; i < MAX_ATTEMPTS; i++) { + if (bad_allocs[i] != NULL && munmap(bad_allocs[i], bad_alloc_lens[i]) < 0) { + sysErrorBelch("unable to release reserved heap"); + } + } + if (at == NULL) { sysErrorBelch("failed to reserve heap memory"); } View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d1d1abcdf7e1e0d95a7b0072d4ae7f8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d1d1abcdf7e1e0d95a7b0072d4ae7f8… You're receiving this email because of your account on gitlab.haskell.org.

1 0