{- (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 Shared term graph (STG) syntax for spineless-tagless code generation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This data type represents programs just before code generation (conversion to @Cmm@): basically, what we have is a stylised form of @CoreSyntax@, the style being one that happens to be ideally suited to spineless tagless code generation. -} {-# LANGUAGE CPP #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE ConstraintKinds #-} module StgSyn ( StgArg(..), GenStgTopBinding(..), GenStgBinding(..), GenStgExpr(..), GenStgRhs(..), GenStgAlt, AltType(..), StgPass(..), BinderP, XRhsClosure, XLet, XLetNoEscape, NoExtFieldSilent, noExtFieldSilent, OutputablePass, UpdateFlag(..), isUpdatable, -- a set of synonyms for the vanilla parameterisation StgTopBinding, StgBinding, StgExpr, StgRhs, StgAlt, -- a set of synonyms for the code gen parameterisation CgStgTopBinding, CgStgBinding, CgStgExpr, CgStgRhs, CgStgAlt, -- a set of synonyms for the lambda lifting parameterisation LlStgTopBinding, LlStgBinding, LlStgExpr, LlStgRhs, LlStgAlt, -- a set of synonyms to distinguish in- and out variants InStgArg, InStgTopBinding, InStgBinding, InStgExpr, InStgRhs, InStgAlt, OutStgArg, OutStgTopBinding, OutStgBinding, OutStgExpr, OutStgRhs, OutStgAlt, -- StgOp StgOp(..), -- utils topStgBindHasCafRefs, stgArgHasCafRefs, stgRhsArity, isDllConApp, stgArgType, stripStgTicksTop, stripStgTicksTopE, stgCaseBndrInScope, pprStgBinding, pprGenStgTopBindings, pprStgTopBindings ) where #include "HsVersions.h" import GhcPrelude import CoreSyn ( AltCon, Tickish ) import CostCentre ( CostCentreStack ) import Data.ByteString ( ByteString ) import Data.Data ( Data ) import Data.List ( intersperse ) import DataCon import DynFlags import ForeignCall ( ForeignCall ) import Id import IdInfo ( mayHaveCafRefs ) import VarSet import Literal ( Literal, literalType ) import Module ( Module ) import Outputable import Packages ( isDllName ) import GHC.Platform import PprCore ( {- instances -} ) import PrimOp ( PrimOp, PrimCall ) import TyCon ( PrimRep(..), TyCon ) import Type ( Type ) import RepType ( typePrimRep1 ) import Util import Data.List.NonEmpty ( NonEmpty, toList ) {- ************************************************************************ * * GenStgBinding * * ************************************************************************ As usual, expressions are interesting; other things are boring. Here are the boring things (except note the @GenStgRhs@), parameterised with respect to binder and occurrence information (just as in @CoreSyn@): -} -- | A top-level binding. data GenStgTopBinding pass -- See Note [CoreSyn top-level string literals] = StgTopLifted (GenStgBinding pass) | StgTopStringLit Id ByteString data GenStgBinding pass = StgNonRec (BinderP pass) (GenStgRhs pass) | StgRec [(BinderP pass, GenStgRhs pass)] {- ************************************************************************ * * StgArg * * ************************************************************************ -} data StgArg = StgVarArg Id | StgLitArg Literal -- | Does this constructor application refer to anything in a different -- *Windows* DLL? -- If so, we can't allocate it statically isDllConApp :: DynFlags -> Module -> DataCon -> [StgArg] -> Bool isDllConApp dflags this_mod con args | platformOS (targetPlatform dflags) == OSMinGW32 = isDllName dflags this_mod (dataConName con) || any is_dll_arg args | otherwise = False where -- NB: typePrimRep1 is legit because any free variables won't have -- unlifted type (there are no unlifted things at top level) is_dll_arg :: StgArg -> Bool is_dll_arg (StgVarArg v) = isAddrRep (typePrimRep1 (idType v)) && isDllName dflags this_mod (idName v) is_dll_arg _ = False -- True of machine addresses; these are the things that don't work across DLLs. -- The key point here is that VoidRep comes out False, so that a top level -- nullary GADT constructor is False for isDllConApp -- -- data T a where -- T1 :: T Int -- -- gives -- -- T1 :: forall a. (a~Int) -> T a -- -- and hence the top-level binding -- -- $WT1 :: T Int -- $WT1 = T1 Int (Coercion (Refl Int)) -- -- The coercion argument here gets VoidRep isAddrRep :: PrimRep -> Bool isAddrRep AddrRep = True isAddrRep LiftedRep = True isAddrRep UnliftedRep = True isAddrRep _ = False -- | Type of an @StgArg@ -- -- Very half baked because we have lost the type arguments. stgArgType :: StgArg -> Type stgArgType (StgVarArg v) = idType v stgArgType (StgLitArg lit) = literalType lit -- | Strip ticks of a given type from an STG expression. stripStgTicksTop :: (Tickish Id -> Bool) -> GenStgExpr p -> ([Tickish Id], GenStgExpr p) stripStgTicksTop p = go [] where go ts (StgTick t e) | p t = go (t:ts) e go ts other = (reverse ts, other) -- | Strip ticks of a given type from an STG expression returning only the expression. stripStgTicksTopE :: (Tickish Id -> Bool) -> GenStgExpr p -> GenStgExpr p stripStgTicksTopE p = go where go (StgTick t e) | p t = go e go other = other -- | Given an alt type and whether the program is unarised, return whether the -- case binder is in scope. -- -- Case binders of unboxed tuple or unboxed sum type always dead after the -- unariser has run. See Note [Post-unarisation invariants]. stgCaseBndrInScope :: AltType -> Bool {- ^ unarised? -} -> Bool stgCaseBndrInScope alt_ty unarised = case alt_ty of AlgAlt _ -> True PrimAlt _ -> True MultiValAlt _ -> not unarised PolyAlt -> True {- ************************************************************************ * * STG expressions * * ************************************************************************ The @GenStgExpr@ data type is parameterised on binder and occurrence info, as before. ************************************************************************ * * GenStgExpr * * ************************************************************************ An application is of a function to a list of atoms (not expressions). Operationally, we want to push the arguments on the stack and call the function. (If the arguments were expressions, we would have to build their closures first.) There is no constructor for a lone variable; it would appear as @StgApp var []@. -} data GenStgExpr pass = StgApp Id -- function [StgArg] -- arguments; may be empty {- ************************************************************************ * * StgConApp and StgPrimApp --- saturated applications * * ************************************************************************ There are specialised forms of application, for constructors, primitives, and literals. -} | StgLit Literal -- StgConApp is vital for returning unboxed tuples or sums -- which can't be let-bound | StgConApp DataCon [StgArg] -- Saturated [Type] -- See Note [Types in StgConApp] in UnariseStg | StgOpApp StgOp -- Primitive op or foreign call [StgArg] -- Saturated. Type -- Result type -- We need to know this so that we can -- assign result registers {- ************************************************************************ * * StgLam * * ************************************************************************ StgLam is used *only* during CoreToStg's work. Before CoreToStg has finished it encodes (\x -> e) as (let f = \x -> e in f) TODO: Encode this via an extension to GenStgExpr à la TTG. -} | StgLam (NonEmpty (BinderP pass)) StgExpr -- Body of lambda {- ************************************************************************ * * GenStgExpr: case-expressions * * ************************************************************************ This has the same boxed/unboxed business as Core case expressions. -} | StgCase (GenStgExpr pass) -- the thing to examine (BinderP pass) -- binds the result of evaluating the scrutinee AltType [GenStgAlt pass] -- The DEFAULT case is always *first* -- if it is there at all {- ************************************************************************ * * GenStgExpr: let(rec)-expressions * * ************************************************************************ The various forms of let(rec)-expression encode most of the interesting things we want to do. - let-closure x = [free-vars] [args] expr in e is equivalent to let x = (\free-vars -> \args -> expr) free-vars @args@ may be empty (and is for most closures). It isn't under circumstances like this: let x = (\y -> y+z) This gets mangled to let-closure x = [z] [y] (y+z) The idea is that we compile code for @(y+z)@ in an environment in which @z@ is bound to an offset from Node, and `y` is bound to an offset from the stack pointer. (A let-closure is an @StgLet@ with a @StgRhsClosure@ RHS.) - let-constructor x = Constructor [args] in e (A let-constructor is an @StgLet@ with a @StgRhsCon@ RHS.) - Letrec-expressions are essentially the same deal as let-closure/ let-constructor, so we use a common structure and distinguish between them with an @is_recursive@ boolean flag. - let-unboxed u = <an arbitrary arithmetic expression in unboxed values> in e All the stuff on the RHS must be fully evaluated. No function calls either! (We've backed away from this toward case-expressions with suitably-magical alts ...) - Advanced stuff here! Not to start with, but makes pattern matching generate more efficient code. let-escapes-not fail = expr in e' Here the idea is that @e'@ guarantees not to put @fail@ in a data structure, or pass it to another function. All @e'@ will ever do is tail-call @fail@. Rather than build a closure for @fail@, all we need do is to record the stack level at the moment of the @let-escapes-not@; then entering @fail@ is just a matter of adjusting the stack pointer back down to that point and entering the code for it. Another example: f x y = let z = huge-expression in if y==1 then z else if y==2 then z else 1 (A let-escapes-not is an @StgLetNoEscape@.) - We may eventually want: let-literal x = Literal in e And so the code for let(rec)-things: -} | StgLet (XLet pass) (GenStgBinding pass) -- right hand sides (see below) (GenStgExpr pass) -- body | StgLetNoEscape (XLetNoEscape pass) (GenStgBinding pass) -- right hand sides (see below) (GenStgExpr pass) -- body {- ************************************************************************* * * GenStgExpr: hpc, scc and other debug annotations * * ************************************************************************* Finally for @hpc@ expressions we introduce a new STG construct. -} | StgTick (Tickish Id) (GenStgExpr pass) -- sub expression -- END of GenStgExpr {- ************************************************************************ * * STG right-hand sides * * ************************************************************************ Here's the rest of the interesting stuff for @StgLet@s; the first flavour is for closures: -} data GenStgRhs pass = StgRhsClosure (XRhsClosure pass) -- ^ Extension point for non-global free var -- list just before 'CodeGen'. CostCentreStack -- ^ CCS to be attached (default is CurrentCCS) !UpdateFlag -- ^ 'ReEntrant' | 'Updatable' | 'SingleEntry' [BinderP pass] -- ^ arguments; if empty, then not a function; -- as above, order is important. (GenStgExpr pass) -- ^ body {- An example may be in order. Consider: let t = \x -> \y -> ... x ... y ... p ... q in e Pulling out the free vars and stylising somewhat, we get the equivalent: let t = (\[p,q] -> \[x,y] -> ... x ... y ... p ...q) p q Stg-operationally, the @[x,y]@ are on the stack, the @[p,q]@ are offsets from @Node@ into the closure, and the code ptr for the closure will be exactly that in parentheses above. The second flavour of right-hand-side is for constructors (simple but important): -} | StgRhsCon CostCentreStack -- CCS to be attached (default is CurrentCCS). -- Top-level (static) ones will end up with -- DontCareCCS, because we don't count static -- data in heap profiles, and we don't set CCCS -- from static closure. DataCon -- Constructor. Never an unboxed tuple or sum, as those -- are not allocated. [StgArg] -- Args -- | Used as a data type index for the stgSyn AST data StgPass = Vanilla | LiftLams | CodeGen -- | Like 'GHC.Hs.Extension.NoExtField', but with an 'Outputable' instance that -- returns 'empty'. data NoExtFieldSilent = NoExtFieldSilent deriving (Data, Eq, Ord) instance Outputable NoExtFieldSilent where ppr _ = empty -- | Used when constructing a term with an unused extension point that should -- not appear in pretty-printed output at all. noExtFieldSilent :: NoExtFieldSilent noExtFieldSilent = NoExtFieldSilent -- TODO: Maybe move this to GHC.Hs.Extension? I'm not sure about the -- implications on build time... -- TODO: Do we really want to the extension point type families to have a closed -- domain? type family BinderP (pass :: StgPass) type instance BinderP 'Vanilla = Id type instance BinderP 'CodeGen = Id type family XRhsClosure (pass :: StgPass) type instance XRhsClosure 'Vanilla = NoExtFieldSilent -- | Code gen needs to track non-global free vars type instance XRhsClosure 'CodeGen = DIdSet type family XLet (pass :: StgPass) type instance XLet 'Vanilla = NoExtFieldSilent type instance XLet 'CodeGen = NoExtFieldSilent type family XLetNoEscape (pass :: StgPass) type instance XLetNoEscape 'Vanilla = NoExtFieldSilent type instance XLetNoEscape 'CodeGen = NoExtFieldSilent stgRhsArity :: StgRhs -> Int stgRhsArity (StgRhsClosure _ _ _ bndrs _) = ASSERT( all isId bndrs ) length bndrs -- The arity never includes type parameters, but they should have gone by now stgRhsArity (StgRhsCon _ _ _) = 0 -- Note [CAF consistency] -- ~~~~~~~~~~~~~~~~~~~~~~ -- -- `topStgBindHasCafRefs` is only used by an assert (`consistentCafInfo` in -- `CoreToStg`) to make sure CAF-ness predicted by `TidyPgm` is consistent with -- reality. -- -- Specifically, if the RHS mentions any Id that itself is marked -- `MayHaveCafRefs`; or if the binding is a top-level updateable thunk; then the -- `Id` for the binding should be marked `MayHaveCafRefs`. The potential trouble -- is that `TidyPgm` computed the CAF info on the `Id` but some transformations -- have taken place since then. topStgBindHasCafRefs :: GenStgTopBinding pass -> Bool topStgBindHasCafRefs (StgTopLifted (StgNonRec _ rhs)) = topRhsHasCafRefs rhs topStgBindHasCafRefs (StgTopLifted (StgRec binds)) = any topRhsHasCafRefs (map snd binds) topStgBindHasCafRefs StgTopStringLit{} = False topRhsHasCafRefs :: GenStgRhs pass -> Bool topRhsHasCafRefs (StgRhsClosure _ _ upd _ body) = -- See Note [CAF consistency] isUpdatable upd || exprHasCafRefs body topRhsHasCafRefs (StgRhsCon _ _ args) = any stgArgHasCafRefs args exprHasCafRefs :: GenStgExpr pass -> Bool exprHasCafRefs (StgApp f args) = stgIdHasCafRefs f || any stgArgHasCafRefs args exprHasCafRefs StgLit{} = False exprHasCafRefs (StgConApp _ args _) = any stgArgHasCafRefs args exprHasCafRefs (StgOpApp _ args _) = any stgArgHasCafRefs args exprHasCafRefs (StgLam _ body) = exprHasCafRefs body exprHasCafRefs (StgCase scrt _ _ alts) = exprHasCafRefs scrt || any altHasCafRefs alts exprHasCafRefs (StgLet _ bind body) = bindHasCafRefs bind || exprHasCafRefs body exprHasCafRefs (StgLetNoEscape _ bind body) = bindHasCafRefs bind || exprHasCafRefs body exprHasCafRefs (StgTick _ expr) = exprHasCafRefs expr bindHasCafRefs :: GenStgBinding pass -> Bool bindHasCafRefs (StgNonRec _ rhs) = rhsHasCafRefs rhs bindHasCafRefs (StgRec binds) = any rhsHasCafRefs (map snd binds) rhsHasCafRefs :: GenStgRhs pass -> Bool rhsHasCafRefs (StgRhsClosure _ _ _ _ body) = exprHasCafRefs body rhsHasCafRefs (StgRhsCon _ _ args) = any stgArgHasCafRefs args altHasCafRefs :: GenStgAlt pass -> Bool altHasCafRefs (_, _, rhs) = exprHasCafRefs rhs stgArgHasCafRefs :: StgArg -> Bool stgArgHasCafRefs (StgVarArg id) = stgIdHasCafRefs id stgArgHasCafRefs _ = False stgIdHasCafRefs :: Id -> Bool stgIdHasCafRefs id = -- We are looking for occurrences of an Id that is bound at top level, and may -- have CAF refs. At this point (after TidyPgm) top-level Ids (whether -- imported or defined in this module) are GlobalIds, so the test is easy. isGlobalId id && mayHaveCafRefs (idCafInfo id) {- ************************************************************************ * * STG case alternatives * * ************************************************************************ Very like in @CoreSyntax@ (except no type-world stuff). The type constructor is guaranteed not to be abstract; that is, we can see its representation. This is important because the code generator uses it to determine return conventions etc. But it's not trivial where there's a module loop involved, because some versions of a type constructor might not have all the constructors visible. So mkStgAlgAlts (in CoreToStg) ensures that it gets the TyCon from the constructors or literals (which are guaranteed to have the Real McCoy) rather than from the scrutinee type. -} type GenStgAlt pass = (AltCon, -- alts: data constructor, [BinderP pass], -- constructor's parameters, GenStgExpr pass) -- ...right-hand side. data AltType = PolyAlt -- Polymorphic (a lifted type variable) | MultiValAlt Int -- Multi value of this arity (unboxed tuple or sum) -- the arity could indeed be 1 for unary unboxed tuple -- or enum-like unboxed sums | AlgAlt TyCon -- Algebraic data type; the AltCons will be DataAlts | PrimAlt PrimRep -- Primitive data type; the AltCons (if any) will be LitAlts {- ************************************************************************ * * The Plain STG parameterisation * * ************************************************************************ This happens to be the only one we use at the moment. -} type StgTopBinding = GenStgTopBinding 'Vanilla type StgBinding = GenStgBinding 'Vanilla type StgExpr = GenStgExpr 'Vanilla type StgRhs = GenStgRhs 'Vanilla type StgAlt = GenStgAlt 'Vanilla type LlStgTopBinding = GenStgTopBinding 'LiftLams type LlStgBinding = GenStgBinding 'LiftLams type LlStgExpr = GenStgExpr 'LiftLams type LlStgRhs = GenStgRhs 'LiftLams type LlStgAlt = GenStgAlt 'LiftLams type CgStgTopBinding = GenStgTopBinding 'CodeGen type CgStgBinding = GenStgBinding 'CodeGen type CgStgExpr = GenStgExpr 'CodeGen type CgStgRhs = GenStgRhs 'CodeGen type CgStgAlt = GenStgAlt 'CodeGen {- Many passes apply a substitution, and it's very handy to have type synonyms to remind us whether or not the substitution has been applied. See CoreSyn for precedence in Core land -} type InStgTopBinding = StgTopBinding type InStgBinding = StgBinding type InStgArg = StgArg type InStgExpr = StgExpr type InStgRhs = StgRhs type InStgAlt = StgAlt type OutStgTopBinding = StgTopBinding type OutStgBinding = StgBinding type OutStgArg = StgArg type OutStgExpr = StgExpr type OutStgRhs = StgRhs type OutStgAlt = StgAlt {- ************************************************************************ * * UpdateFlag * * ************************************************************************ This is also used in @LambdaFormInfo@ in the @ClosureInfo@ module. A @ReEntrant@ closure may be entered multiple times, but should not be updated or blackholed. An @Updatable@ closure should be updated after evaluation (and may be blackholed during evaluation). A @SingleEntry@ closure will only be entered once, and so need not be updated but may safely be blackholed. -} data UpdateFlag = ReEntrant | Updatable | SingleEntry instance Outputable UpdateFlag where ppr u = char $ case u of ReEntrant -> 'r' Updatable -> 'u' SingleEntry -> 's' isUpdatable :: UpdateFlag -> Bool isUpdatable ReEntrant = False isUpdatable SingleEntry = False isUpdatable Updatable = True {- ************************************************************************ * * StgOp * * ************************************************************************ An StgOp allows us to group together PrimOps and ForeignCalls. It's quite useful to move these around together, notably in StgOpApp and COpStmt. -} data StgOp = StgPrimOp PrimOp | StgPrimCallOp PrimCall | StgFCallOp ForeignCall Type -- The Type, which is obtained from the foreign import declaration -- itself, is needed by the stg-to-cmm pass to determine the offset to -- apply to unlifted boxed arguments in GHC.StgToCmm.Foreign. See Note -- [Unlifted boxed arguments to foreign calls] {- ************************************************************************ * * Pretty-printing * * ************************************************************************ Robin Popplestone asked for semi-colon separators on STG binds; here's hoping he likes terminators instead... Ditto for case alternatives. -} type OutputablePass pass = ( Outputable (XLet pass) , Outputable (XLetNoEscape pass) , Outputable (XRhsClosure pass) , OutputableBndr (BinderP pass) ) pprGenStgTopBinding :: OutputablePass pass => GenStgTopBinding pass -> SDoc pprGenStgTopBinding (StgTopStringLit bndr str) = hang (hsep [pprBndr LetBind bndr, equals]) 4 (pprHsBytes str <> semi) pprGenStgTopBinding (StgTopLifted bind) = pprGenStgBinding bind pprGenStgBinding :: OutputablePass pass => GenStgBinding pass -> SDoc pprGenStgBinding (StgNonRec bndr rhs) = hang (hsep [pprBndr LetBind bndr, equals]) 4 (ppr rhs <> semi) pprGenStgBinding (StgRec pairs) = vcat [ text "Rec {" , vcat (intersperse blankLine (map ppr_bind pairs)) , text "end Rec }" ] where ppr_bind (bndr, expr) = hang (hsep [pprBndr LetBind bndr, equals]) 4 (ppr expr <> semi) pprGenStgTopBindings :: (OutputablePass pass) => [GenStgTopBinding pass] -> SDoc pprGenStgTopBindings binds = vcat $ intersperse blankLine (map pprGenStgTopBinding binds) pprStgBinding :: StgBinding -> SDoc pprStgBinding = pprGenStgBinding pprStgTopBindings :: [StgTopBinding] -> SDoc pprStgTopBindings = pprGenStgTopBindings instance Outputable StgArg where ppr = pprStgArg instance OutputablePass pass => Outputable (GenStgTopBinding pass) where ppr = pprGenStgTopBinding instance OutputablePass pass => Outputable (GenStgBinding pass) where ppr = pprGenStgBinding instance OutputablePass pass => Outputable (GenStgExpr pass) where ppr = pprStgExpr instance OutputablePass pass => Outputable (GenStgRhs pass) where ppr rhs = pprStgRhs rhs pprStgArg :: StgArg -> SDoc pprStgArg (StgVarArg var) = ppr var pprStgArg (StgLitArg con) = ppr con pprStgExpr :: OutputablePass pass => GenStgExpr pass -> SDoc -- special case pprStgExpr (StgLit lit) = ppr lit -- general case pprStgExpr (StgApp func args) = hang (ppr func) 4 (sep (map (ppr) args)) pprStgExpr (StgConApp con args _) = hsep [ ppr con, brackets (interppSP args) ] pprStgExpr (StgOpApp op args _) = hsep [ pprStgOp op, brackets (interppSP args)] pprStgExpr (StgLam bndrs body) = sep [ char '\\' <+> ppr_list (map (pprBndr LambdaBind) (toList bndrs)) <+> text "->", pprStgExpr body ] where ppr_list = brackets . fsep . punctuate comma -- special case: let v = <very specific thing> -- in -- let ... -- in -- ... -- -- Very special! Suspicious! (SLPJ) {- pprStgExpr (StgLet srt (StgNonRec bndr (StgRhsClosure cc bi free_vars upd_flag args rhs)) expr@(StgLet _ _)) = ($$) (hang (hcat [text "let { ", ppr bndr, ptext (sLit " = "), ppr cc, pp_binder_info bi, text " [", whenPprDebug (interppSP free_vars), ptext (sLit "] \\"), ppr upd_flag, text " [", interppSP args, char ']']) 8 (sep [hsep [ppr rhs, text "} in"]])) (ppr expr) -} -- special case: let ... in let ... pprStgExpr (StgLet ext bind expr@StgLet{}) = ($$) (sep [hang (text "let" <+> ppr ext <+> text "{") 2 (hsep [pprGenStgBinding bind, text "} in"])]) (ppr expr) -- general case pprStgExpr (StgLet ext bind expr) = sep [hang (text "let" <+> ppr ext <+> text "{") 2 (pprGenStgBinding bind), hang (text "} in ") 2 (ppr expr)] pprStgExpr (StgLetNoEscape ext bind expr) = sep [hang (text "let-no-escape" <+> ppr ext <+> text "{") 2 (pprGenStgBinding bind), hang (text "} in ") 2 (ppr expr)] pprStgExpr (StgTick tickish expr) = sdocWithDynFlags $ \dflags -> if gopt Opt_SuppressTicks dflags then pprStgExpr expr else sep [ ppr tickish, pprStgExpr expr ] -- Don't indent for a single case alternative. pprStgExpr (StgCase expr bndr alt_type [alt]) = sep [sep [text "case", nest 4 (hsep [pprStgExpr expr, whenPprDebug (dcolon <+> ppr alt_type)]), text "of", pprBndr CaseBind bndr, char '{'], pprStgAlt False alt, char '}'] pprStgExpr (StgCase expr bndr alt_type alts) = sep [sep [text "case", nest 4 (hsep [pprStgExpr expr, whenPprDebug (dcolon <+> ppr alt_type)]), text "of", pprBndr CaseBind bndr, char '{'], nest 2 (vcat (map (pprStgAlt True) alts)), char '}'] pprStgAlt :: OutputablePass pass => Bool -> GenStgAlt pass -> SDoc pprStgAlt indent (con, params, expr) | indent = hang altPattern 4 (ppr expr <> semi) | otherwise = sep [altPattern, ppr expr <> semi] where altPattern = (hsep [ppr con, sep (map (pprBndr CasePatBind) params), text "->"]) pprStgOp :: StgOp -> SDoc pprStgOp (StgPrimOp op) = ppr op pprStgOp (StgPrimCallOp op)= ppr op pprStgOp (StgFCallOp op _) = ppr op instance Outputable AltType where ppr PolyAlt = text "Polymorphic" ppr (MultiValAlt n) = text "MultiAlt" <+> ppr n ppr (AlgAlt tc) = text "Alg" <+> ppr tc ppr (PrimAlt tc) = text "Prim" <+> ppr tc pprStgRhs :: OutputablePass pass => GenStgRhs pass -> SDoc pprStgRhs (StgRhsClosure ext cc upd_flag args body) = sdocWithDynFlags $ \dflags -> hang (hsep [if gopt Opt_SccProfilingOn dflags then ppr cc else empty, if not $ gopt Opt_SuppressStgExts dflags then ppr ext else empty, char '\\' <> ppr upd_flag, brackets (interppSP args)]) 4 (ppr body) pprStgRhs (StgRhsCon cc con args) = hcat [ ppr cc, space, ppr con, text "! ", brackets (interppSP args)]