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[GHC] #7785: Module-local function not specialized with ConstraintKinds
by GHC 13 Apr '13

13 Apr '13

#7785: Module-local function not specialized with ConstraintKinds ------------------------------------+--------------------------------------- Reporter: akio | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.2 | Keywords: specialisation Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Runtime performance bug | Blockedby: Blocking: | Related: ------------------------------------+--------------------------------------- In the attached program, 'shared' is not exported and only used with f = [], but it doesn't get specialized in the core. On the other hand, shared', which does not involve !ConstraintKinds, gets correctly specialized. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7785> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7783: MultiWayIf should start a new layout
by GHC 13 Apr '13

13 Apr '13

#7783: MultiWayIf should start a new layout -----------------------------+---------------------------------------------- Reporter: exbb2 | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.2 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: #4359 -----------------------------+---------------------------------------------- Currently, MultiWayIf doesn't fully replace old {{{case () of _}}} form. This outputs 3: {{{ {-# LANGUAGE MultiWayIf #-} x = case () of _ | False -> case () of _ | False -> 1 | False -> 2 | True -> 3 main = print (x :: Int) }}} but this errors out: {{{ {-# LANGUAGE MultiWayIf #-} x = if | False -> if | False -> 1 | False -> 2 | True -> 3 main = print (x :: Int) }}} Every other syntax introducing guards starts a layout; MultiWayIf's current behavior leads to subtle logic bugs for those unaware that MultiWayIf is special. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7783> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7782: flag to run the demand analysis a second time
by GHC 13 Apr '13

13 Apr '13

#7782: flag to run the demand analysis a second time -----------------------------+---------------------------------------------- Reporter: nfrisby | Owner: Type: task | Status: new Priority: normal | Component: Compiler Version: 7.7 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: 4941, 5302, 6087, 4962 -----------------------------+---------------------------------------------- There are some tickets documenting runtime bugs that can be cleaned up by running the demand analyzer a second time at the end of the pipeline: #4941, #5302, #6087. #6070 ? Others? Here's the effects on nofib. Run time didn't seem to change as drastically. {{{ Allocations ------------------------------------------------------------------------------- Program O2/O2 late-dmd/O2 late-dmd/late-dmd ------------------------------------------------------------------------------- cryptarithm2 25078168 +0.0% +8.0% nucleic2 98331744 +0.0% +3.2% cichelli 80310632 +0.0% -22.9% fasta 401159024 -9.1% -9.1% fulsom 321427240 +0.0% -2.6% k-nucleotide 4125102928 -0.0% -4.8% knights 2037984 +0.0% -3.7% mandel2 1041840 +0.0% -21.4% parstof 3103208 +0.0% -1.4% reverse-complem 155188304 -12.8% -12.8% simple 226412800 -0.0% -1.0% }}} Note that it improves a couple tests significantly just via changes in the base libraries. For cryptarithm2, see my comments on #4941. This might indicate that #4962 should be re-opened. For nucleic2, in var_most_distant_atom, an inlined let grows numerous closures by a significant amount. I'm not sure where to lay the blame for this. Note however, that just making nucleic2's data types use strict !Float fields changes its allocation -72.4%, so maybe this "bad practice" corner case is a small issue. The main remaining task beyond the attached patch is to repair the treatment of wrapper's strictness signatures in .hi files. Because the second demand analysis might change a these signatures, the current compaction mechanism that .hi uses results in ill-formed Core. For the attached patch, I've just disabled that .hi compaction mechanism, but this just needlessly bloats .hi files. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7782> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7775: Mark intentionally omitted type class instances
by GHC 13 Apr '13

13 Apr '13

#7775: Mark intentionally omitted type class instances -----------------------------+---------------------------------------------- Reporter: Lemming | Owner: Type: feature request | Status: new Priority: normal | Component: Compiler (Type checker) Version: 7.6.2 | Keywords: instance warning Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- In GHCi I get {{{ Prelude> 2+3::Char <interactive>:2:2: No instance for (Num Char) arising from a use of `+' Possible fix: add an instance declaration for (Num Char) In the expression: 2 + 3 :: Char In an equation for `it': it = 2 + 3 :: Char }}} In many cases users now actually try to implement the instance Num Char, but this is certainly not a good idea. I would like to tell the user whenever an instance is intentionally unimplemented and why it is missing. Like so {{{ {-# NOINSTANCE Num Char where "There is no sound arithmetic on characters." #-} }}} The syntax after NOINSTANCE should be like in an instance declaration. It shall be treated like a type class instance, e.g. it shall be checked whether the same instance already exists, or whether it is orphan, or whether it is not Haskell 98, and it should require to enable according extensions like MultiParamTypeClasses. If on resolution a non-instance is chosen then the compiler should print the custom warning "There is no sound arithmetic on characters." instead of "probable fix: add instance". -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7775> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7774: T5313 fails
by GHC 13 Apr '13

13 Apr '13

#7774: T5313 fails ---------------------------------+------------------------------------------ Reporter: igloo | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHC API | Version: 7.7 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ T5313 fails {{{ =====> T5313(normal) 76 of 104 [0, 0, 0] cd . && '/home/ian/ghc/git/ghc/inplace/bin/ghc-stage2' -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history -o T5313 T5313.hs -package ghc >T5313.comp.stderr 2>&1 cd . && ./T5313 "/home/ian/ghc/git/ghc/inplace/lib" </dev/null >T5313.run.stdout 2>T5313.run.stderr Wrong exit code (expected 0 , actual 1 ) Stdout: Stderr: T5313: <command line>: can't load .so/.DLL for: /home/ian/ghc/git/ghc/libraries/ghc-prim/dist-install/build/libHSghc- prim-0.3.1.0-ghc7.7.20130316.so (/home/ian/ghc/git/ghc/libraries/ghc-prim /dist-install/build/libHSghc-prim-0.3.1.0-ghc7.7.20130316.so: undefined symbol: stg_newByteArrayzh) *** unexpected failure for T5313(normal) }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7774> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7771: RTS should provide stg_sel_n_noupd_closure
by GHC 13 Apr '13

13 Apr '13

#7771: RTS should provide stg_sel_n_noupd_closure ---------------------------------+------------------------------------------ Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.2 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ In `StgStdThunks.cmm` we define info tables `stg_sel_1_upd_info`, etc, for "selector thunks", thus: {{{ #define SELECTOR_CODE_UPD(offset) \ INFO_TABLE_SELECTOR(stg_sel_##offset##_upd, offset, THUNK_SELECTOR, "stg_sel_upd", "stg_sel_upd") \ (P_ node) \ ...etc... }}} But we should ALSO define info tables for ''non-updatable'' selector thunks, thus `stg_sel_1_nonupd_info` etc. We didn't generate any such selectors before, but now I'm implementing cardinality analysis, we are. Would it be possible to beef up this macro to to generate both info tables? Simply omit the update for the `nonupd` version. (It wasn't quite obvious to me how to do this.) That would allow me to get rid of this hack in `CLabel` {{{ pprCLbl (RtsLabel (RtsSelectorInfoTable _upd_reqd offset)) = hcat [ptext (sLit "stg_sel_"), text (show offset), ptext (sLit "_upd_info") -- RTS only has updatable selector thunks at the moment -- so we use just them -- ptext (if upd_reqd -- then (sLit "_upd_info") -- else (sLit "_noupd_info")) ] }}} Thanks -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7771> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7768: "untracked content" in fresh clone of haskeline
by GHC 13 Apr '13

13 Apr '13

#7768: "untracked content" in fresh clone of haskeline -------------------------+-------------------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Component: Build System Version: 7.7 | Keywords: Os: MacOS X | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -------------------------+-------------------------------------------------- This sequence of events happened today: {{{ ~> git clone http://darcs.haskell.org/ghc.git; cd ghc; ./sync-all --testsuite get ... ~/ghc> git status # On branch master # Changes not staged for commit: # (use "git add <file>..." to update what will be committed) # (use "git checkout -- <file>..." to discard changes in working directory) # (commit or discard the untracked or modified content in submodules) # # modified: libraries/haskeline (untracked content) # no changes added to commit (use "git add" and/or "git commit -a") ~/ghc> cd libraries/haskeline ~/ghc/libraries/haskeline> git status # Not currently on any branch. # Untracked files: # (use "git add <file>..." to include in what will be committed) # # "tests/dummy-I\314\202\302\274I\314\202\302\261I\314\210\302\203/" nothing added to commit but untracked files present (use "git add" to track) }}} It seems harmless, but I can't seem to make the problem go away. I'm on a Mac. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7768> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7767: "internal error: evacuate: strange closure type 154886248" crash
by GHC 13 Apr '13

13 Apr '13

#7767: "internal error: evacuate: strange closure type 154886248" crash --------------------------+------------------------------------------------- Reporter: rodlogic | Owner: Type: bug | Status: new Priority: normal | Component: Runtime System Version: 7.6.2 | Keywords: Os: MacOS X | Architecture: x86_64 (amd64) Failure: Runtime crash | Blockedby: Blocking: | Related: --------------------------+------------------------------------------------- I have a simple Main.hs that uses the GHC API to produce a '''ParsedModule'''. I then use ghc-vis this value, which is when I get: {{{ Starting ... Setting dynamic flags ... Guessing and adding target ... Analyze dependencies ... Getting module summary ... Parsing module ... Main: internal error: evacuate: strange closure type 154886248 (GHC version 7.6.2 for x86_64_apple_darwin) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug [1] 7583 abort ./Main }}} Here is the Main.hs: {{{ {-# LANGUAGE CPP #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE RecordWildCards #-} {- See the following link for additional details about the API: http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/API -} module Main where import Module import RdrName import OccName import BasicTypes --import Bag --import HsDecls --import Control.Monad import Control.Exception (throw) import GHC hiding (loadModule) import SrcLoc import MonadUtils import GHC.Paths (libdir) import HscTypes --import DynFlags import Unsafe.Coerce --import Bag (bagToList) --import Outputable --import Name import Data.Typeable import Text.Show import Data.Foldable(forM_) import GHC.Exts --import GHC.HeapView import GHC.Vis main :: IO () main = do doMain getLine return () --libdir = "/Library/Frameworks/GHC.framework/Versions/7.6.2-x86_64/usr/lib" doMain = do putStrLn "Starting ..." runGhc (Just libdir) $ do -- liftIO $ putStrLn "Setting dynamic flags ..." dflags <- getSessionDynFlags setSessionDynFlags (dflags) -- liftIO $ putStrLn "Guessing and adding target ..." -- guessTarget :: GhcMonad m => String -> Maybe Phase -> m Target target <- guessTarget "Test.hs" Nothing -- addTarget :: GhcMonad m => Target -> m () addTarget target --liftIO $ putStrLn "Loading all targets ..." --_ <- load (LoadUpTo modName) liftIO $ putStrLn "Analyze dependencies ..." -- depanal :: GhcMonad m => -- [ModuleName] -- ^ excluded modules -- -> Bool -- ^ allow duplicate roots -- -> m ModuleGraph modGraph <- depanal [] False let modName = mkModuleName "Test" liftIO $ putStrLn "Getting module summary ..." -- getModSummary :: GhcMonad m => ModuleName -> m ModSummary modSummary <- getModSummary modName liftIO $ putStrLn "Parsing module ..." --data ParsedModule = ParsedModule { pm_mod_summary :: ModSummary -- , pm_parsed_source :: ParsedSource -- , pm_extra_src_files :: [FilePath] } -- type ParsedSource = Located (HsModule RdrName) -- type Located e = GenLocated SrcSpan e -- parseModule :: GhcMonad m => ModSummary -> m ParsedModule parsedMod <- parseModule modSummary liftIO $ vis liftIO $ view parsedMod "parsedMod" --let parsedSrc = pm_parsed_source parsedMod ----walkLocSource parsedSrc ----typecheckModule :: GhcMonad m => ParsedModule -> m TypecheckedModule --liftIO $ putStrLn "Type checking module ..." --typedMod <- typecheckModule parsedMod ----let parsedMod = tm_parsed_module typedMod ----walkLocSource (pm_parsed_source parsedMod) --let rnSource = tm_renamed_source typedMod ----walkRenamedSource rnSource ---- desugarModule :: GhcMonad m => TypecheckedModule -> m DesugaredModule --liftIO $ putStrLn "Desugaring module ..." --desugaredMod <- desugarModule typedMod return () }}} I have built it using: {{{ ghc --make -L/usr/lib -package ghc Main.hs -threaded }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7767> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7765: Odd error message for `runghc` with missing `main` function.
by GHC 13 Apr '13

13 Apr '13

#7765: Odd error message for `runghc` with missing `main` function. -----------------------------+---------------------------------------------- Reporter: isaacdupree | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.1 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- {{{ % cat what.hs module Main where {} % runghc what.hs what.hs:1:33: Not in scope: `main' Perhaps you meant `min' (imported from Prelude) }}} '`ghc what.hs`' gives a rather more sensible message. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7765> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7762: internal error: evacuate(static): strange closure type 4
by GHC 13 Apr '13

13 Apr '13

#7762: internal error: evacuate(static): strange closure type 4 --------------------------+------------------------------------------------- Reporter: rthiemann | Owner: Type: bug | Status: new Priority: normal | Component: Runtime System Version: 7.0.4 | Keywords: Os: Linux | Architecture: x86_64 (amd64) Failure: Runtime crash | Blockedby: Blocking: | Related: --------------------------+------------------------------------------------- resample: internal error: evacuate(static): strange closure type 4 (GHC version 7.0.4 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Bug occurs reproducable after running the main program for around 8 minutes and consuming 25 GB of RAM. ghc -rtsopts --make Main -o main ./main +RTS -K3000m -RTS > someFile.txt -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7762> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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