2 % (c) The GRASP Project, Glasgow University, 1992-2002
6 TcRn, TcM, RnM, -- The monad is opaque outside this module
8 -- Standard monadic operations
9 thenM, thenM_, returnM, failM,
11 -- Non-standard operations
12 runTcRn, fixM, tryM, ioToTcRn,
13 newMutVar, readMutVar, writeMutVar,
14 getEnv, setEnv, updEnv, unsafeInterleaveM,
16 -- The environment types
17 Env(..), TopEnv(..), TcGblEnv(..),
18 TcLclEnv(..), RnLclEnv(..),
21 RnMode(..), isInterfaceMode, isCmdLineMode,
22 EntityUsage, emptyUsages, ErrCtxt,
23 ImportAvails(..), emptyImportAvails, plusImportAvails,
24 plusAvail, pruneAvails,
25 AvailEnv, emptyAvailEnv, unitAvailEnv, plusAvailEnv,
26 mkAvailEnv, lookupAvailEnv, availEnvElts, addAvail,
33 Stage(..), topStage, topSpliceStage,
34 Level, impLevel, topLevel,
37 Inst(..), InstOrigin(..), InstLoc, pprInstLoc,
38 LIE, emptyLIE, unitLIE, plusLIE, consLIE,
39 plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
45 #include "HsVersions.h"
47 import HsSyn ( PendingSplice, HsOverLit, MonoBinds, RuleDecl, ForeignDecl )
48 import RnHsSyn ( RenamedHsExpr, RenamedPat, RenamedArithSeqInfo )
49 import HscTypes ( GhciMode, ExternalPackageState, HomePackageTable, NameCache,
50 GlobalRdrEnv, LocalRdrEnv, FixityEnv, TypeEnv, TyThing,
51 Avails, GenAvailInfo(..), AvailInfo, availName,
52 IsBootInterface, Deprecations )
53 import Packages ( PackageName )
54 import TcType ( TcTyVarSet, TcType, TcTauType, TcThetaType, TcPredType, TcKind,
55 tcCmpPred, tcCmpType, tcCmpTypes )
56 import InstEnv ( DFunId, InstEnv )
59 import NameSet ( NameSet, emptyNameSet )
61 import Class ( Class )
62 import Var ( Id, TyVar )
63 import VarEnv ( TidyEnv )
65 import SrcLoc ( SrcLoc )
66 import VarSet ( IdSet )
67 import ErrUtils ( Messages, Message )
68 import CmdLineOpts ( DynFlags )
69 import UniqSupply ( UniqSupply )
70 import BasicTypes ( IPName )
71 import Util ( thenCmp )
74 import DATA_IOREF ( IORef, newIORef, readIORef, writeIORef )
75 import UNSAFE_IO ( unsafeInterleaveIO )
76 import FIX_IO ( fixIO )
77 import EXCEPTION ( Exception )
78 import Maybe ( mapMaybe )
79 import ListSetOps ( unionLists )
80 import Panic ( tryMost )
85 type TcRef a = IORef a
86 type TcId = Id -- Type may be a TcType
90 %************************************************************************
92 Standard monad definition for TcRn
93 All the combinators for the monad can be found in TcRnMonad
95 %************************************************************************
97 The monad itself has to be defined here,
98 because it is mentioned by ErrCtxt
101 newtype TcRn m a = TcRn (Env m -> IO a)
104 type TcM a = TcRn TcLclEnv a
105 type RnM a = TcRn RnLclEnv a
107 returnM :: a -> TcRn m a
108 returnM a = TcRn (\ env -> return a)
110 thenM :: TcRn m a -> (a -> TcRn m b) -> TcRn m b
111 thenM (TcRn m) f = TcRn (\ env -> do { r <- m env ;
114 thenM_ :: TcRn m a -> TcRn m b -> TcRn m b
115 thenM_ (TcRn m) f = TcRn (\ env -> do { m env ; unTcRn f env })
118 failM = TcRn (\ env -> ioError (userError "TcRn failure"))
120 instance Monad (TcRn m) where
124 fail s = failM -- Ignore the string
128 %************************************************************************
130 Fundmantal combinators specific to the monad
132 %************************************************************************
137 runTcRn :: Env m -> TcRn m a -> IO a
138 runTcRn env (TcRn m) = m env
141 The fixpoint combinator
144 {-# NOINLINE fixM #-}
145 -- Aargh! Not inlining fixTc alleviates a space leak problem.
146 -- Normally fixTc is used with a lazy tuple match: if the optimiser is
147 -- shown the definition of fixTc, it occasionally transforms the code
148 -- in such a way that the code generator doesn't spot the selector
151 fixM :: (a -> TcRn m a) -> TcRn m a
152 fixM f = TcRn (\ env -> fixIO (\ r -> unTcRn (f r) env))
158 tryM :: TcRn m r -> TcRn m (Either Exception r)
159 -- Reflect exception into TcRn monad
160 tryM (TcRn thing) = TcRn (\ env -> tryMost (thing env))
166 unsafeInterleaveM :: TcRn m a -> TcRn m a
167 unsafeInterleaveM (TcRn m) = TcRn (\ env -> unsafeInterleaveIO (m env))
172 Performing arbitrary I/O, plus the read/write var (for efficiency)
175 ioToTcRn :: IO a -> TcRn m a
176 ioToTcRn io = TcRn (\ env -> io)
178 newMutVar :: a -> TcRn m (TcRef a)
179 newMutVar val = TcRn (\ env -> newIORef val)
181 writeMutVar :: TcRef a -> a -> TcRn m ()
182 writeMutVar var val = TcRn (\ env -> writeIORef var val)
184 readMutVar :: TcRef a -> TcRn m a
185 readMutVar var = TcRn (\ env -> readIORef var)
188 Getting the environment
191 getEnv :: TcRn m (Env m)
192 {-# INLINE getEnv #-}
193 getEnv = TcRn (\ env -> return env)
195 setEnv :: Env n -> TcRn n a -> TcRn m a
196 {-# INLINE setEnv #-}
197 setEnv new_env (TcRn m) = TcRn (\ env -> m new_env)
199 updEnv :: (Env m -> Env n) -> TcRn n a -> TcRn m a
200 {-# INLINE updEnv #-}
201 updEnv upd (TcRn m) = TcRn (\ env -> m (upd env))
205 %************************************************************************
207 The main environment types
209 %************************************************************************
212 data Env a -- Changes as we move into an expression
214 env_top :: TopEnv, -- Top-level stuff that never changes
215 -- Mainly a bunch of updatable refs
216 -- Includes all info about imported things
217 env_gbl :: TcGblEnv, -- Info about things defined at the top leve
218 -- of the module being compiled
220 env_lcl :: a, -- Different for the type checker
223 env_loc :: SrcLoc -- Source location
226 data TopEnv -- Built once at top level then does not change
227 -- Concerns imported stuff
228 -- Exceptions: error recovery points, meta computation points
230 top_mode :: GhciMode,
231 top_dflags :: DynFlags,
233 -- Stuff about imports
234 top_eps :: TcRef ExternalPackageState,
235 -- PIT, ImportedModuleInfo
236 -- DeclsMap, IfaceRules, IfaceInsts, InstGates
237 -- TypeEnv, InstEnv, RuleBase
239 top_hpt :: HomePackageTable,
240 -- The home package table that we've accumulated while
241 -- compiling the home package,
242 -- *excluding* the module we are compiling right now.
243 -- (In one-shot mode the current module is the only
244 -- home-package module, so tc_hpt is empty. All other
245 -- modules count as "external-package" modules.)
246 -- tc_hpt is not mutable because we only demand-load
247 -- external packages; the home package is eagerly
248 -- loaded by the compilation manager.
250 -- The global name supply
251 top_nc :: TcRef NameCache, -- Maps original names to Names
252 top_us :: TcRef UniqSupply, -- Unique supply for this module
253 top_errs :: TcRef Messages
256 -- TcGblEnv describes the top-level of the module at the
257 -- point at which the typechecker is finished work.
258 -- It is this structure that is handed on to the desugarer
262 tcg_mod :: Module, -- Module being compiled
263 tcg_usages :: TcRef EntityUsage, -- What version of what entities
264 -- have been used from other home-pkg modules
265 tcg_rdr_env :: GlobalRdrEnv, -- Top level envt; used during renaming
266 tcg_fix_env :: FixityEnv, -- Ditto
267 tcg_default :: [Type], -- Types used for defaulting
269 tcg_type_env :: TypeEnv, -- Global type env for the module we are compiling now
270 -- All TyCons and Classes (for this module) end up in here right away,
271 -- along with their derived constructors, selectors.
273 -- (Ids defined in this module start in the local envt,
274 -- though they move to the global envt during zonking)
277 tcg_ist :: Name -> Maybe TyThing, -- Imported symbol table
278 -- Global type env: a combination of tcg_eps, tcg_hpt
279 -- (but *not* tcg_type_env; no deep reason)
280 -- When the PCS changes this must be refreshed,
281 -- notably after running some compile-time code
283 tcg_inst_env :: InstEnv, -- Global instance env: a combination of
284 -- tc_pcs, tc_hpt, *and* tc_insts
286 -- Now a bunch of things about this module that are simply
287 -- accumulated, but never consulted until the end.
288 -- Nevertheless, it's convenient to accumulate them along
289 -- with the rest of the info from this module.
290 tcg_exports :: Avails, -- What is exported
291 tcg_imports :: ImportAvails, -- Information about what was imported
292 -- from where, including things bound
294 -- The next fields are always fully zonked
295 tcg_binds :: MonoBinds Id, -- Value bindings in this module
296 tcg_deprecs :: Deprecations, -- ...Deprecations
297 tcg_insts :: [DFunId], -- ...Instances
298 tcg_rules :: [RuleDecl Id], -- ...Rules
299 tcg_fords :: [ForeignDecl Id] -- ...Foreign import & exports
304 %************************************************************************
306 The local typechecker environment
308 %************************************************************************
310 The Global-Env/Local-Env story
311 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
312 During type checking, we keep in the tcg_type_env
313 * All types and classes
314 * All Ids derived from types and classes (constructors, selectors)
316 At the end of type checking, we zonk the local bindings,
317 and as we do so we add to the tcg_type_env
318 * Locally defined top-level Ids
320 Why? Because they are now Ids not TcIds. This final GlobalEnv is
321 a) fed back (via the knot) to typechecking the
322 unfoldings of interface signatures
323 b) used in the ModDetails of this module
328 tcl_ctxt :: ErrCtxt, -- Error context
330 tcl_level :: Stage, -- Template Haskell context
332 tcl_env :: NameEnv TcTyThing, -- The local type environment: Ids and TyVars
333 -- defined in this module
335 tcl_tyvars :: TcRef TcTyVarSet, -- The "global tyvars"
336 -- Namely, the in-scope TyVars bound in tcl_lenv,
337 -- plus the tyvars mentioned in the types of
338 -- Ids bound in tcl_lenv
339 -- Why mutable? see notes with tcGetGlobalTyVars
341 tcl_lie :: TcRef LIE -- Place to accumulate type constraints
347 = Comp -- Ordinary compiling, at level topLevel
348 | Splice Level -- Inside a splice
349 | Brack Level -- Inside brackets;
350 (TcRef [PendingSplice]) -- accumulate pending splices here
351 (TcRef LIE) -- and type constraints here
352 topStage, topSpliceStage :: Stage
354 topSpliceStage = Splice (topLevel - 1) -- Stage for the body of a top-level splice
357 impLevel, topLevel :: Level
358 topLevel = 1 -- Things dedined at top level of this module
359 impLevel = 0 -- Imported things; they can be used inside a top level splice
363 -- g1 = $(map ...) is OK
364 -- g2 = $(f ...) is not OK; because we havn't compiled f yet
367 = AGlobal TyThing -- Used only in the return type of a lookup
368 | ATcId TcId Level -- Ids defined in this module; may not be fully zonked
369 | ATyVar TyVar -- Type variables
370 | AThing TcKind -- Used temporarily, during kind checking
371 -- Here's an example of how the AThing guy is used
372 -- Suppose we are checking (forall a. T a Int):
373 -- 1. We first bind (a -> AThink kv), where kv is a kind variable.
374 -- 2. Then we kind-check the (T a Int) part.
375 -- 3. Then we zonk the kind variable.
376 -- 4. Now we know the kind for 'a', and we add (a -> ATyVar a::K) to the environment
380 type ErrCtxt = [TidyEnv -> TcM (TidyEnv, Message)]
381 -- Innermost first. Monadic so that we have a chance
382 -- to deal with bound type variables just before error
383 -- message construction
387 %************************************************************************
389 The local renamer environment
391 %************************************************************************
397 rn_lenv :: LocalRdrEnv -- Local name envt
398 -- Does *not* include global name envt; may shadow it
399 -- Includes both ordinary variables and type variables;
400 -- they are kept distinct because tyvar have a different
401 -- occurrence contructor (Name.TvOcc)
402 -- We still need the unsullied global name env so that
403 -- we can look up record field names
406 data RnMode = SourceMode -- Renaming source code
407 | InterfaceMode Module -- Renaming interface declarations from M
408 | CmdLineMode -- Renaming a command-line expression
410 isInterfaceMode (InterfaceMode _) = True
411 isInterfaceMode _ = False
413 isCmdLineMode CmdLineMode = True
414 isCmdLineMode _ = False
418 %************************************************************************
422 %************************************************************************
424 EntityUsage tells what things are actually need in order to compile this
425 module. It is used for generating the usage-version field of the ModIface.
427 Note that we do not record version info for entities from
428 other (non-home) packages. If the package changes, GHC doesn't help.
431 type EntityUsage = NameSet
432 -- The Names are all the (a) home-package
433 -- (b) "big" (i.e. no data cons, class ops)
434 -- (c) non-locally-defined
436 -- names that have been slurped in so far.
437 -- This is used to generate the "usage" information for this module.
439 emptyUsages :: EntityUsage
440 emptyUsages = emptyNameSet
444 %************************************************************************
446 Operations over ImportAvails
448 %************************************************************************
450 ImportAvails summarises what was imported from where, irrespective
451 of whether the imported htings are actually used or not
452 It is used * when porcessing the export list
453 * when constructing usage info for the inteface file
454 * to identify the list of directly imported modules
455 for initialisation purposes
461 -- All the things that are available from the import
462 -- Its domain is all the "main" things;
463 -- i.e. *excluding* class ops and constructors
464 -- (which appear inside their parent AvailTC)
466 imp_unqual :: ModuleEnv AvailEnv,
467 -- Used to figure out "module M" export specifiers
468 -- Domain is only modules with *unqualified* imports
469 -- (see 1.4 Report Section 5.1.1)
470 -- We keep the stuff as an AvailEnv so that it's easy to
471 -- combine stuff coming from different (unqualified)
472 -- imports of the same module
474 imp_mods :: ModuleEnv (Module, Bool),
475 -- Domain is all directly-imported modules
476 -- Bool is True if there was an unrestricted import
477 -- (i.e. not a selective list)
478 -- We need the Module in the range because we can't get
479 -- the keys of a ModuleEnv
481 -- (a) to help construct the usage information in
482 -- the interface file; if we import everything we
483 -- need to recompile if the module version changes
484 -- (b) to specify what child modules to initialise
486 imp_dep_mods :: ModuleEnv (ModuleName, IsBootInterface),
487 -- Home-package modules needed by the module being compiled
489 -- It doesn't matter whether any of these dependencies are actually
490 -- *used* when compiling the module; they are listed if they are below
491 -- it at all. For example, suppose M imports A which imports X. Then
492 -- compiling M might not need to consult X.hi, but X is still listed
493 -- in M's dependencies.
495 imp_dep_pkgs :: [PackageName],
496 -- Packages needed by the module being compiled, whether
497 -- directly, or via other modules in this package, or via
498 -- modules imported from other packages.
500 imp_orphs :: [ModuleName]
501 -- Orphan modules below us in the import tree
504 emptyImportAvails :: ImportAvails
505 emptyImportAvails = ImportAvails { imp_env = emptyAvailEnv,
506 imp_unqual = emptyModuleEnv,
507 imp_mods = emptyModuleEnv,
508 imp_dep_mods = emptyModuleEnv,
512 plusImportAvails :: ImportAvails -> ImportAvails -> ImportAvails
514 (ImportAvails { imp_env = env1, imp_unqual = unqual1, imp_mods = mods1,
515 imp_dep_mods = dmods1, imp_dep_pkgs = dpkgs1, imp_orphs = orphs1 })
516 (ImportAvails { imp_env = env2, imp_unqual = unqual2, imp_mods = mods2,
517 imp_dep_mods = dmods2, imp_dep_pkgs = dpkgs2, imp_orphs = orphs2 })
518 = ImportAvails { imp_env = env1 `plusAvailEnv` env2,
519 imp_unqual = plusModuleEnv_C plusAvailEnv unqual1 unqual2,
520 imp_mods = mods1 `plusModuleEnv` mods2,
521 imp_dep_mods = plusModuleEnv_C plus_mod_dep dmods1 dmods2,
522 imp_dep_pkgs = dpkgs1 `unionLists` dpkgs2,
523 imp_orphs = orphs1 `unionLists` orphs2 }
525 plus_mod_dep (m1, boot1) (m2, boot2)
526 = WARN( not (m1 == m2), (ppr m1 <+> ppr m2) $$ (ppr boot1 <+> ppr boot2) )
527 -- Check mod-names match
528 (m1, boot1 && boot2) -- If either side can "see" a non-hi-boot interface, use that
531 %************************************************************************
533 Avails, AvailEnv, etc
535 v%************************************************************************
538 plusAvail (Avail n1) (Avail n2) = Avail n1
539 plusAvail (AvailTC n1 ns1) (AvailTC n2 ns2) = AvailTC n2 (ns1 `unionLists` ns2)
542 plusAvail a1 a2 = pprPanic "RnEnv.plusAvail" (hsep [ppr a1,ppr a2])
545 -------------------------
546 pruneAvails :: (Name -> Bool) -- Keep if this is True
549 pruneAvails keep avails
550 = mapMaybe del avails
552 del :: AvailInfo -> Maybe AvailInfo -- Nothing => nothing left!
553 del (Avail n) | keep n = Just (Avail n)
554 | otherwise = Nothing
555 del (AvailTC n ns) | null ns' = Nothing
556 | otherwise = Just (AvailTC n ns')
561 ---------------------------------------
563 ---------------------------------------
566 type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it
568 emptyAvailEnv :: AvailEnv
569 emptyAvailEnv = emptyNameEnv
571 unitAvailEnv :: AvailInfo -> AvailEnv
572 unitAvailEnv a = unitNameEnv (availName a) a
574 plusAvailEnv :: AvailEnv -> AvailEnv -> AvailEnv
575 plusAvailEnv = plusNameEnv_C plusAvail
577 lookupAvailEnv = lookupNameEnv
579 availEnvElts = nameEnvElts
581 addAvail :: AvailEnv -> AvailInfo -> AvailEnv
582 addAvail avails avail = extendNameEnv_C plusAvail avails (availName avail) avail
584 mkAvailEnv :: [AvailInfo] -> AvailEnv
585 -- 'avails' may have several items with the same availName
586 -- E.g import Ix( Ix(..), index )
587 -- will give Ix(Ix,index,range) and Ix(index)
588 -- We want to combine these; addAvail does that
589 mkAvailEnv avails = foldl addAvail emptyAvailEnv avails
592 %************************************************************************
594 \subsection{Where from}
596 %************************************************************************
598 The @WhereFrom@ type controls where the renamer looks for an interface file
602 = ImportByUser IsBootInterface -- Ordinary user import (perhaps {-# SOURCE #-})
604 | ImportForUsage IsBootInterface -- Import when chasing usage info from an interaface file
605 -- Failure in this case is not an error
607 | ImportBySystem -- Non user import.
609 instance Outputable WhereFrom where
610 ppr (ImportByUser is_boot) | is_boot = ptext SLIT("{- SOURCE -}")
612 ppr (ImportForUsage is_boot) | is_boot = ptext SLIT("{- USAGE SOURCE -}")
613 | otherwise = ptext SLIT("{- USAGE -}")
614 ppr ImportBySystem = ptext SLIT("{- SYSTEM -}")
618 %************************************************************************
620 \subsection[Inst-types]{@Inst@ types}
622 v%************************************************************************
624 An @Inst@ is either a dictionary, an instance of an overloaded
625 literal, or an instance of an overloaded value. We call the latter a
626 ``method'' even though it may not correspond to a class operation.
627 For example, we might have an instance of the @double@ function at
628 type Int, represented by
630 Method 34 doubleId [Int] origin
642 TcId -- The overloaded function
643 -- This function will be a global, local, or ClassOpId;
644 -- inside instance decls (only) it can also be an InstId!
645 -- The id needn't be completely polymorphic.
646 -- You'll probably find its name (for documentation purposes)
647 -- inside the InstOrigin
649 [TcType] -- The types to which its polymorphic tyvars
650 -- should be instantiated.
651 -- These types must saturate the Id's foralls.
653 TcThetaType -- The (types of the) dictionaries to which the function
654 -- must be applied to get the method
656 TcTauType -- The type of the method
660 -- INVARIANT: in (Method u f tys theta tau loc)
661 -- type of (f tys dicts(from theta)) = tau
665 HsOverLit -- The literal from the occurrence site
666 -- INVARIANT: never a rebindable-syntax literal
667 -- Reason: tcSyntaxName does unification, and we
668 -- don't want to deal with that during tcSimplify
669 TcType -- The type at which the literal is used
673 @Insts@ are ordered by their class/type info, rather than by their
674 unique. This allows the context-reduction mechanism to use standard finite
675 maps to do their stuff.
678 instance Ord Inst where
681 instance Eq Inst where
682 (==) i1 i2 = case i1 `cmpInst` i2 of
686 cmpInst (Dict _ pred1 _) (Dict _ pred2 _) = pred1 `tcCmpPred` pred2
687 cmpInst (Dict _ _ _) other = LT
689 cmpInst (Method _ _ _ _ _ _) (Dict _ _ _) = GT
690 cmpInst (Method _ id1 tys1 _ _ _) (Method _ id2 tys2 _ _ _) = (id1 `compare` id2) `thenCmp` (tys1 `tcCmpTypes` tys2)
691 cmpInst (Method _ _ _ _ _ _) other = LT
693 cmpInst (LitInst _ _ _ _) (Dict _ _ _) = GT
694 cmpInst (LitInst _ _ _ _) (Method _ _ _ _ _ _) = GT
695 cmpInst (LitInst _ lit1 ty1 _) (LitInst _ lit2 ty2 _) = (lit1 `compare` lit2) `thenCmp` (ty1 `tcCmpType` ty2)
699 %************************************************************************
701 \subsection[Inst-collections]{LIE: a collection of Insts}
703 %************************************************************************
708 isEmptyLIE = isEmptyBag
710 unitLIE inst = unitBag inst
711 mkLIE insts = listToBag insts
712 plusLIE lie1 lie2 = lie1 `unionBags` lie2
713 consLIE inst lie = inst `consBag` lie
714 plusLIEs lies = unionManyBags lies
715 lieToList = bagToList
716 listToLIE = listToBag
720 %************************************************************************
722 \subsection[Inst-origin]{The @InstOrigin@ type}
724 %************************************************************************
726 The @InstOrigin@ type gives information about where a dictionary came from.
727 This is important for decent error message reporting because dictionaries
728 don't appear in the original source code. Doubtless this type will evolve...
730 It appears in TcMonad because there are a couple of error-message-generation
731 functions that deal with it.
734 type InstLoc = (InstOrigin, SrcLoc, ErrCtxt)
737 = OccurrenceOf Name -- Occurrence of an overloaded identifier
739 | IPOcc (IPName Name) -- Occurrence of an implicit parameter
740 | IPBind (IPName Name) -- Binding site of an implicit parameter
744 | DataDeclOrigin -- Typechecking a data declaration
746 | InstanceDeclOrigin -- Typechecking an instance decl
748 | LiteralOrigin HsOverLit -- Occurrence of a literal
750 | PatOrigin RenamedPat
752 | ArithSeqOrigin RenamedArithSeqInfo -- [x..], [x..y] etc
753 | PArrSeqOrigin RenamedArithSeqInfo -- [:x..y:] and [:x,y..z:]
755 | SignatureOrigin -- A dict created from a type signature
756 | Rank2Origin -- A dict created when typechecking the argument
757 -- of a rank-2 typed function
759 | DoOrigin -- The monad for a do expression
761 | ClassDeclOrigin -- Manufactured during a class decl
763 | InstanceSpecOrigin Class -- in a SPECIALIZE instance pragma
766 -- When specialising instances the instance info attached to
767 -- each class is not yet ready, so we record it inside the
768 -- origin information. This is a bit of a hack, but it works
769 -- fine. (Patrick is to blame [WDP].)
771 | ValSpecOrigin Name -- in a SPECIALIZE pragma for a value
773 -- Argument or result of a ccall
774 -- Dictionaries with this origin aren't actually mentioned in the
775 -- translated term, and so need not be bound. Nor should they
776 -- be abstracted over.
778 | CCallOrigin String -- CCall label
779 (Maybe RenamedHsExpr) -- Nothing if it's the result
780 -- Just arg, for an argument
782 | LitLitOrigin String -- the litlit
784 | UnknownOrigin -- Help! I give up...
788 pprInstLoc :: InstLoc -> SDoc
789 pprInstLoc (orig, locn, ctxt)
790 = hsep [text "arising from", pp_orig orig, text "at", ppr locn]
792 pp_orig (OccurrenceOf name)
793 = hsep [ptext SLIT("use of"), quotes (ppr name)]
795 = hsep [ptext SLIT("use of implicit parameter"), quotes (ppr name)]
796 pp_orig (IPBind name)
797 = hsep [ptext SLIT("binding for implicit parameter"), quotes (ppr name)]
798 pp_orig RecordUpdOrigin
799 = ptext SLIT("a record update")
800 pp_orig DataDeclOrigin
801 = ptext SLIT("the data type declaration")
802 pp_orig InstanceDeclOrigin
803 = ptext SLIT("the instance declaration")
804 pp_orig (LiteralOrigin lit)
805 = hsep [ptext SLIT("the literal"), quotes (ppr lit)]
806 pp_orig (PatOrigin pat)
807 = hsep [ptext SLIT("the pattern"), quotes (ppr pat)]
808 pp_orig (ArithSeqOrigin seq)
809 = hsep [ptext SLIT("the arithmetic sequence"), quotes (ppr seq)]
810 pp_orig (PArrSeqOrigin seq)
811 = hsep [ptext SLIT("the parallel array sequence"), quotes (ppr seq)]
812 pp_orig (SignatureOrigin)
813 = ptext SLIT("a type signature")
814 pp_orig (Rank2Origin)
815 = ptext SLIT("a function with an overloaded argument type")
817 = ptext SLIT("a do statement")
818 pp_orig (ClassDeclOrigin)
819 = ptext SLIT("a class declaration")
820 pp_orig (InstanceSpecOrigin clas ty)
821 = hsep [text "a SPECIALIZE instance pragma; class",
822 quotes (ppr clas), text "type:", ppr ty]
823 pp_orig (ValSpecOrigin name)
824 = hsep [ptext SLIT("a SPECIALIZE user-pragma for"), quotes (ppr name)]
825 pp_orig (CCallOrigin clabel Nothing{-ccall result-})
826 = hsep [ptext SLIT("the result of the _ccall_ to"), quotes (text clabel)]
827 pp_orig (CCallOrigin clabel (Just arg_expr))
828 = hsep [ptext SLIT("an argument in the _ccall_ to"), quotes (text clabel) <> comma,
829 text "namely", quotes (ppr arg_expr)]
830 pp_orig (LitLitOrigin s)
831 = hsep [ptext SLIT("the ``literal-literal''"), quotes (text s)]
832 pp_orig (UnknownOrigin)
833 = ptext SLIT("...oops -- I don't know where the overloading came from!")