%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnExpr]{Renaming of expressions}
Basically dependency analysis.
-Handles @Match@, @GRHSsAndBinds@, @HsExpr@, and @Qualifier@ datatypes. In
+Handles @Match@, @GRHSs@, @HsExpr@, and @Qualifier@ datatypes. In
general, all of these functions return a renamed thing, and a set of
free variables.
\begin{code}
-#include "HsVersions.h"
-
module RnExpr (
- rnMatch, rnGRHSsAndBinds, rnPat,
- checkPrecMatch
+ rnLExpr, rnExpr, rnStmts
) where
-IMP_Ubiq()
-IMPORT_DELOOPER(RnLoop) -- break the RnPass/RnExpr/RnBinds loops
+#include "HsVersions.h"
+import RnSource ( rnSrcDecls, rnSplice, checkTH )
+import RnBinds ( rnLocalBindsAndThen, rnValBinds,
+ rnMatchGroup, trimWith )
import HsSyn
-import RdrHsSyn
import RnHsSyn
-import RnMonad
+import TcRnMonad
import RnEnv
-import CmdLineOpts ( opt_GlasgowExts )
-import BasicTypes ( Fixity(..), FixityDirection(..) )
-import PrelInfo ( numClass_RDR, fractionalClass_RDR, eqClass_RDR, ccallableClass_RDR,
- creturnableClass_RDR, monadZeroClass_RDR, enumClass_RDR, ordClass_RDR,
- ratioDataCon_RDR, negate_RDR
- )
-import TysPrim ( charPrimTyCon, addrPrimTyCon, intPrimTyCon,
- floatPrimTyCon, doublePrimTyCon
- )
-import TyCon ( TyCon )
-import Id ( GenId )
-import ErrUtils ( addErrLoc, addShortErrLocLine )
-import Name
-import Pretty
-import UniqFM ( lookupUFM{-, ufmToList ToDo:rm-} )
-import UniqSet ( emptyUniqSet, unitUniqSet,
- unionUniqSets, unionManyUniqSets,
- SYN_IE(UniqSet)
- )
-import Util ( Ord3(..), removeDups, panic, pprPanic, assertPanic )
+import OccName ( plusOccEnv )
+import RnNames ( getLocalDeclBinders, extendRdrEnvRn )
+import RnTypes ( rnHsTypeFVs, rnLPat, rnOverLit, rnPatsAndThen, rnLit,
+ mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec,
+ dupFieldErr, checkTupSize )
+import DynFlags ( DynFlag(..) )
+import BasicTypes ( FixityDirection(..) )
+import PrelNames ( thFAKE, hasKey, assertIdKey, assertErrorName,
+ loopAName, choiceAName, appAName, arrAName, composeAName, firstAName,
+ negateName, thenMName, bindMName, failMName )
+import Name ( Name, nameOccName, nameIsLocalOrFrom )
+import NameSet
+import RdrName ( RdrName, emptyGlobalRdrEnv, extendLocalRdrEnv, lookupLocalRdrEnv )
+import LoadIface ( loadHomeInterface )
+import UniqFM ( isNullUFM )
+import UniqSet ( emptyUniqSet )
+import List ( nub )
+import Util ( isSingleton )
+import ListSetOps ( removeDups )
+import Maybes ( fromJust )
import Outputable
+import SrcLoc ( Located(..), unLoc, getLoc, cmpLocated )
+import FastString
+import List ( unzip4 )
\end{code}
-*********************************************************
-* *
-\subsection{Patterns}
-* *
-*********************************************************
-
-\begin{code}
-rnPat :: RdrNamePat -> RnMS s RenamedPat
-
-rnPat WildPatIn = returnRn WildPatIn
-
-rnPat (VarPatIn name)
- = lookupBndrRn name `thenRn` \ vname ->
- returnRn (VarPatIn vname)
-
-rnPat (LitPatIn lit)
- = litOccurrence lit `thenRn_`
- lookupImplicitOccRn eqClass_RDR `thenRn_` -- Needed to find equality on pattern
- returnRn (LitPatIn lit)
-
-rnPat (LazyPatIn pat)
- = rnPat pat `thenRn` \ pat' ->
- returnRn (LazyPatIn pat')
-
-rnPat (AsPatIn name pat)
- = rnPat pat `thenRn` \ pat' ->
- lookupBndrRn name `thenRn` \ vname ->
- returnRn (AsPatIn vname pat')
-
-rnPat (ConPatIn con pats)
- = lookupOccRn con `thenRn` \ con' ->
- mapRn rnPat pats `thenRn` \ patslist ->
- returnRn (ConPatIn con' patslist)
-
-rnPat (ConOpPatIn pat1 con _ pat2)
- = rnPat pat1 `thenRn` \ pat1' ->
- lookupOccRn con `thenRn` \ con' ->
- lookupFixity con `thenRn` \ fixity ->
- rnPat pat2 `thenRn` \ pat2' ->
- mkConOpPatRn pat1' con' fixity pat2'
-
--- Negated patters can only be literals, and they are dealt with
--- by negating the literal at compile time, not by using the negation
--- operation in Num. So we don't need to make an implicit reference
--- to negate_RDR.
-rnPat neg@(NegPatIn pat)
- = checkRn (valid_neg_pat pat) (negPatErr neg)
- `thenRn_`
- rnPat pat `thenRn` \ pat' ->
- returnRn (NegPatIn pat')
- where
- valid_neg_pat (LitPatIn (HsInt _)) = True
- valid_neg_pat (LitPatIn (HsFrac _)) = True
- valid_neg_pat _ = False
-
-rnPat (ParPatIn pat)
- = rnPat pat `thenRn` \ pat' ->
- returnRn (ParPatIn pat')
-
-rnPat (NPlusKPatIn name lit)
- = litOccurrence lit `thenRn_`
- lookupImplicitOccRn ordClass_RDR `thenRn_`
- lookupBndrRn name `thenRn` \ name' ->
- returnRn (NPlusKPatIn name' lit)
-
-rnPat (ListPatIn pats)
- = addImplicitOccRn listType_name `thenRn_`
- mapRn rnPat pats `thenRn` \ patslist ->
- returnRn (ListPatIn patslist)
-
-rnPat (TuplePatIn pats)
- = addImplicitOccRn (tupleType_name (length pats)) `thenRn_`
- mapRn rnPat pats `thenRn` \ patslist ->
- returnRn (TuplePatIn patslist)
-
-rnPat (RecPatIn con rpats)
- = lookupOccRn con `thenRn` \ con' ->
- rnRpats rpats `thenRn` \ rpats' ->
- returnRn (RecPatIn con' rpats')
-\end{code}
-
-************************************************************************
-* *
-\subsection{Match}
-* *
-************************************************************************
-
-\begin{code}
-rnMatch :: RdrNameMatch -> RnMS s (RenamedMatch, FreeVars)
-
-rnMatch (PatMatch pat match)
- = bindLocalsRn "pattern" binders $ \ new_binders ->
- rnPat pat `thenRn` \ pat' ->
- rnMatch match `thenRn` \ (match', fvMatch) ->
- returnRn (PatMatch pat' match', fvMatch `minusNameSet` mkNameSet new_binders)
- where
- binders = collectPatBinders pat
-
-rnMatch (GRHSMatch grhss_and_binds)
- = rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', fvs) ->
- returnRn (GRHSMatch grhss_and_binds', fvs)
-\end{code}
-
%************************************************************************
%* *
-\subsubsection{Guarded right-hand sides (GRHSsAndBinds)}
+\subsubsection{Expressions}
%* *
%************************************************************************
\begin{code}
-rnGRHSsAndBinds :: RdrNameGRHSsAndBinds -> RnMS s (RenamedGRHSsAndBinds, FreeVars)
-
-rnGRHSsAndBinds (GRHSsAndBindsIn grhss binds)
- = rnBinds binds $ \ binds' ->
- rnGRHSs grhss `thenRn` \ (grhss', fvGRHS) ->
- returnRn (GRHSsAndBindsIn grhss' binds', fvGRHS)
- where
- rnGRHSs [] = returnRn ([], emptyNameSet)
-
- rnGRHSs (grhs:grhss)
- = rnGRHS grhs `thenRn` \ (grhs', fvs) ->
- rnGRHSs grhss `thenRn` \ (grhss', fvss) ->
- returnRn (grhs' : grhss', fvs `unionNameSets` fvss)
-
- rnGRHS (GRHS guard expr locn)
- = pushSrcLocRn locn $
- (if not (opt_GlasgowExts || is_standard_guard guard) then
- addWarnRn (nonStdGuardErr guard)
- else
- returnRn ()
- ) `thenRn_`
-
- (rnStmts rnExpr guard $ \ guard' ->
- -- This nested thing deals with scope and
- -- the free vars of the guard, and knocking off the
- -- free vars of the rhs that are bound by the guard
-
- rnExpr expr `thenRn` \ (expr', fvse) ->
- returnRn (GRHS guard' expr' locn, fvse))
-
- rnGRHS (OtherwiseGRHS expr locn)
- = pushSrcLocRn locn $
- rnExpr expr `thenRn` \ (expr', fvs) ->
- returnRn (GRHS [] expr' locn, fvs)
-
- -- Standard Haskell 1.4 guards are just a single boolean
- -- expression, rather than a list of qualifiers as in the
- -- Glasgow extension
- is_standard_guard [GuardStmt _ _] = True
- is_standard_guard other = False
-\end{code}
+rnExprs :: [LHsExpr RdrName] -> RnM ([LHsExpr Name], FreeVars)
+rnExprs ls = rnExprs' ls emptyUniqSet
+ where
+ rnExprs' [] acc = returnM ([], acc)
+ rnExprs' (expr:exprs) acc
+ = rnLExpr expr `thenM` \ (expr', fvExpr) ->
-%************************************************************************
-%* *
-\subsubsection{Expressions}
-%* *
-%************************************************************************
+ -- Now we do a "seq" on the free vars because typically it's small
+ -- or empty, especially in very long lists of constants
+ let
+ acc' = acc `plusFV` fvExpr
+ in
+ (grubby_seqNameSet acc' rnExprs') exprs acc' `thenM` \ (exprs', fvExprs) ->
+ returnM (expr':exprs', fvExprs)
-\begin{code}
-rnExprs :: [RdrNameHsExpr] -> RnMS s ([RenamedHsExpr], FreeVars)
-rnExprs ls =
- rnExprs' ls [] `thenRn` \ (exprs, fvExprs) ->
- returnRn (exprs, unionManyNameSets fvExprs)
-
-rnExprs' [] acc = returnRn ([], acc)
-rnExprs' (expr:exprs) acc
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- rnExprs' exprs (fvExpr:acc) `thenRn` \ (exprs', fvExprs) ->
- returnRn (expr':exprs', fvExprs)
+-- Grubby little function to do "seq" on namesets; replace by proper seq when GHC can do seq
+grubby_seqNameSet ns result | isNullUFM ns = result
+ | otherwise = result
\end{code}
-Variables. We look up the variable and return the resulting name. The
-interesting question is what the free-variable set should be. We
-don't want to return imported or prelude things as free vars. So we
-look at the Name returned from the lookup, and make it part of the
-free-var set iff if it's a LocallyDefined Name.
-\end{itemize}
+Variables. We look up the variable and return the resulting name.
\begin{code}
-rnExpr :: RdrNameHsExpr -> RnMS s (RenamedHsExpr, FreeVars)
+rnLExpr :: LHsExpr RdrName -> RnM (LHsExpr Name, FreeVars)
+rnLExpr = wrapLocFstM rnExpr
+
+rnExpr :: HsExpr RdrName -> RnM (HsExpr Name, FreeVars)
rnExpr (HsVar v)
- = lookupOccRn v `thenRn` \ vname ->
- returnRn (HsVar vname, if isLocallyDefined vname
- then unitNameSet vname
- else emptyUniqSet)
+ = lookupOccRn v `thenM` \ name ->
+ doptM Opt_IgnoreAsserts `thenM` \ ignore_asserts ->
+ if name `hasKey` assertIdKey && not ignore_asserts then
+ -- We expand it to (GHC.Err.assertError location_string)
+ mkAssertErrorExpr `thenM` \ (e, fvs) ->
+ returnM (e, fvs `addOneFV` name)
+ -- Keep 'assert' as a free var, to ensure it's not reported as unused!
+ else
+ -- The normal case. Even if the Id was 'assert', if we are
+ -- ignoring assertions we leave it as GHC.Base.assert;
+ -- this function just ignores its first arg.
+ returnM (HsVar name, unitFV name)
+
+rnExpr (HsIPVar v)
+ = newIPNameRn v `thenM` \ name ->
+ returnM (HsIPVar name, emptyFVs)
rnExpr (HsLit lit)
- = litOccurrence lit `thenRn_`
- returnRn (HsLit lit, emptyNameSet)
+ = rnLit lit `thenM_`
+ returnM (HsLit lit, emptyFVs)
-rnExpr (HsLam match)
- = rnMatch match `thenRn` \ (match', fvMatch) ->
- returnRn (HsLam match', fvMatch)
+rnExpr (HsOverLit lit)
+ = rnOverLit lit `thenM` \ (lit', fvs) ->
+ returnM (HsOverLit lit', fvs)
rnExpr (HsApp fun arg)
- = rnExpr fun `thenRn` \ (fun',fvFun) ->
- rnExpr arg `thenRn` \ (arg',fvArg) ->
- returnRn (HsApp fun' arg', fvFun `unionNameSets` fvArg)
+ = rnLExpr fun `thenM` \ (fun',fvFun) ->
+ rnLExpr arg `thenM` \ (arg',fvArg) ->
+ returnM (HsApp fun' arg', fvFun `plusFV` fvArg)
-rnExpr (OpApp e1 op@(HsVar op_name) _ e2)
- = rnExpr e1 `thenRn` \ (e1', fv_e1) ->
- rnExpr e2 `thenRn` \ (e2', fv_e2) ->
- rnExpr op `thenRn` \ (op', fv_op) ->
+rnExpr (OpApp e1 op _ e2)
+ = rnLExpr e1 `thenM` \ (e1', fv_e1) ->
+ rnLExpr e2 `thenM` \ (e2', fv_e2) ->
+ rnLExpr op `thenM` \ (op'@(L _ (HsVar op_name)), fv_op) ->
-- Deal with fixity
-- When renaming code synthesised from "deriving" declarations
- -- we're in Interface mode, and we should ignore fixity; assume
- -- that the deriving code generator got the association correct
- lookupFixity op_name `thenRn` \ fixity ->
- getModeRn `thenRn` \ mode ->
- (case mode of
- SourceMode -> mkOpAppRn e1' op' fixity e2'
- InterfaceMode _ -> returnRn (OpApp e1' op' fixity e2')
- ) `thenRn` \ final_e ->
-
- returnRn (final_e,
- fv_e1 `unionNameSets` fv_op `unionNameSets` fv_e2)
-
-rnExpr (NegApp e n)
- = rnExpr e `thenRn` \ (e', fv_e) ->
- lookupImplicitOccRn negate_RDR `thenRn` \ neg ->
- mkNegAppRn e' (HsVar neg) `thenRn` \ final_e ->
- returnRn (final_e, fv_e)
+ -- we used to avoid fixity stuff, but we can't easily tell any
+ -- more, so I've removed the test. Adding HsPars in TcGenDeriv
+ -- should prevent bad things happening.
+ lookupFixityRn op_name `thenM` \ fixity ->
+ mkOpAppRn e1' op' fixity e2' `thenM` \ final_e ->
+
+ returnM (final_e,
+ fv_e1 `plusFV` fv_op `plusFV` fv_e2)
+
+rnExpr (NegApp e _)
+ = rnLExpr e `thenM` \ (e', fv_e) ->
+ lookupSyntaxName negateName `thenM` \ (neg_name, fv_neg) ->
+ mkNegAppRn e' neg_name `thenM` \ final_e ->
+ returnM (final_e, fv_e `plusFV` fv_neg)
rnExpr (HsPar e)
- = rnExpr e `thenRn` \ (e', fvs_e) ->
- returnRn (HsPar e', fvs_e)
-
-rnExpr (SectionL expr op)
- = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
- rnExpr op `thenRn` \ (op', fvs_op) ->
- returnRn (SectionL expr' op', fvs_op `unionNameSets` fvs_expr)
-
-rnExpr (SectionR op expr)
- = rnExpr op `thenRn` \ (op', fvs_op) ->
- rnExpr expr `thenRn` \ (expr', fvs_expr) ->
- returnRn (SectionR op' expr', fvs_op `unionNameSets` fvs_expr)
-
-rnExpr (CCall fun args may_gc is_casm fake_result_ty)
- = lookupImplicitOccRn ccallableClass_RDR `thenRn_`
- lookupImplicitOccRn creturnableClass_RDR `thenRn_`
- rnExprs args `thenRn` \ (args', fvs_args) ->
- returnRn (CCall fun args' may_gc is_casm fake_result_ty, fvs_args)
-
-rnExpr (HsSCC label expr)
- = rnExpr expr `thenRn` \ (expr', fvs_expr) ->
- returnRn (HsSCC label expr', fvs_expr)
-
-rnExpr (HsCase expr ms src_loc)
- = pushSrcLocRn src_loc $
- rnExpr expr `thenRn` \ (new_expr, e_fvs) ->
- mapAndUnzipRn rnMatch ms `thenRn` \ (new_ms, ms_fvs) ->
- returnRn (HsCase new_expr new_ms src_loc, unionManyNameSets (e_fvs : ms_fvs))
+ = rnLExpr e `thenM` \ (e', fvs_e) ->
+ returnM (HsPar e', fvs_e)
+
+-- Template Haskell extensions
+-- Don't ifdef-GHCI them because we want to fail gracefully
+-- (not with an rnExpr crash) in a stage-1 compiler.
+rnExpr e@(HsBracket br_body)
+ = checkTH e "bracket" `thenM_`
+ rnBracket br_body `thenM` \ (body', fvs_e) ->
+ returnM (HsBracket body', fvs_e)
+
+rnExpr e@(HsSpliceE splice)
+ = rnSplice splice `thenM` \ (splice', fvs) ->
+ returnM (HsSpliceE splice', fvs)
+
+rnExpr section@(SectionL expr op)
+ = rnLExpr expr `thenM` \ (expr', fvs_expr) ->
+ rnLExpr op `thenM` \ (op', fvs_op) ->
+ checkSectionPrec InfixL section op' expr' `thenM_`
+ returnM (SectionL expr' op', fvs_op `plusFV` fvs_expr)
+
+rnExpr section@(SectionR op expr)
+ = rnLExpr op `thenM` \ (op', fvs_op) ->
+ rnLExpr expr `thenM` \ (expr', fvs_expr) ->
+ checkSectionPrec InfixR section op' expr' `thenM_`
+ returnM (SectionR op' expr', fvs_op `plusFV` fvs_expr)
+
+rnExpr (HsCoreAnn ann expr)
+ = rnLExpr expr `thenM` \ (expr', fvs_expr) ->
+ returnM (HsCoreAnn ann expr', fvs_expr)
+
+rnExpr (HsSCC lbl expr)
+ = rnLExpr expr `thenM` \ (expr', fvs_expr) ->
+ returnM (HsSCC lbl expr', fvs_expr)
+
+rnExpr (HsLam matches)
+ = rnMatchGroup LambdaExpr matches `thenM` \ (matches', fvMatch) ->
+ returnM (HsLam matches', fvMatch)
+
+rnExpr (HsCase expr matches)
+ = rnLExpr expr `thenM` \ (new_expr, e_fvs) ->
+ rnMatchGroup CaseAlt matches `thenM` \ (new_matches, ms_fvs) ->
+ returnM (HsCase new_expr new_matches, e_fvs `plusFV` ms_fvs)
rnExpr (HsLet binds expr)
- = rnBinds binds $ \ binds' ->
- rnExpr expr `thenRn` \ (expr',fvExpr) ->
- returnRn (HsLet binds' expr', fvExpr)
-
-rnExpr (HsDo do_or_lc stmts src_loc)
- = pushSrcLocRn src_loc $
- lookupImplicitOccRn monadZeroClass_RDR `thenRn_` -- Forces Monad to come too
- (rnStmts rnExpr stmts $ \ stmts' ->
- returnRn (HsDo do_or_lc stmts' src_loc, emptyNameSet))
-
-rnExpr (ExplicitList exps)
- = addImplicitOccRn listType_name `thenRn_`
- rnExprs exps `thenRn` \ (exps', fvs) ->
- returnRn (ExplicitList exps', fvs)
-
-rnExpr (ExplicitTuple exps)
- = addImplicitOccRn (tupleType_name (length exps)) `thenRn_`
- rnExprs exps `thenRn` \ (exps', fvExps) ->
- returnRn (ExplicitTuple exps', fvExps)
-
-rnExpr (RecordCon (HsVar con) rbinds)
- = lookupOccRn con `thenRn` \ conname ->
- rnRbinds "construction" rbinds `thenRn` \ (rbinds', fvRbinds) ->
- returnRn (RecordCon (HsVar conname) rbinds', fvRbinds)
-
-rnExpr (RecordUpd expr rbinds)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- rnRbinds "update" rbinds `thenRn` \ (rbinds', fvRbinds) ->
- returnRn (RecordUpd expr' rbinds', fvExpr `unionNameSets` fvRbinds)
+ = rnLocalBindsAndThen binds $ \ binds' ->
+ rnLExpr expr `thenM` \ (expr',fvExpr) ->
+ returnM (HsLet binds' expr', fvExpr)
+
+rnExpr e@(HsDo do_or_lc stmts body _)
+ = do { ((stmts', body'), fvs) <- rnStmts do_or_lc stmts $
+ rnLExpr body
+ ; return (HsDo do_or_lc stmts' body' placeHolderType, fvs) }
+
+rnExpr (ExplicitList _ exps)
+ = rnExprs exps `thenM` \ (exps', fvs) ->
+ returnM (ExplicitList placeHolderType exps', fvs `addOneFV` listTyCon_name)
+
+rnExpr (ExplicitPArr _ exps)
+ = rnExprs exps `thenM` \ (exps', fvs) ->
+ returnM (ExplicitPArr placeHolderType exps', fvs)
+
+rnExpr e@(ExplicitTuple exps boxity)
+ = checkTupSize tup_size `thenM_`
+ rnExprs exps `thenM` \ (exps', fvs) ->
+ returnM (ExplicitTuple exps' boxity, fvs `addOneFV` tycon_name)
+ where
+ tup_size = length exps
+ tycon_name = tupleTyCon_name boxity tup_size
+
+rnExpr (RecordCon con_id _ rbinds)
+ = lookupLocatedOccRn con_id `thenM` \ conname ->
+ rnRbinds "construction" rbinds `thenM` \ (rbinds', fvRbinds) ->
+ returnM (RecordCon conname noPostTcExpr rbinds',
+ fvRbinds `addOneFV` unLoc conname)
+
+rnExpr (RecordUpd expr rbinds _ _)
+ = rnLExpr expr `thenM` \ (expr', fvExpr) ->
+ rnRbinds "update" rbinds `thenM` \ (rbinds', fvRbinds) ->
+ returnM (RecordUpd expr' rbinds' placeHolderType placeHolderType,
+ fvExpr `plusFV` fvRbinds)
rnExpr (ExprWithTySig expr pty)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- rnHsSigType (\ sty -> text "an expression") pty `thenRn` \ pty' ->
- returnRn (ExprWithTySig expr' pty', fvExpr)
-
-rnExpr (HsIf p b1 b2 src_loc)
- = pushSrcLocRn src_loc $
- rnExpr p `thenRn` \ (p', fvP) ->
- rnExpr b1 `thenRn` \ (b1', fvB1) ->
- rnExpr b2 `thenRn` \ (b2', fvB2) ->
- returnRn (HsIf p' b1' b2' src_loc, unionManyNameSets [fvP, fvB1, fvB2])
-
-rnExpr (ArithSeqIn seq)
- = lookupImplicitOccRn enumClass_RDR `thenRn_`
- rn_seq seq `thenRn` \ (new_seq, fvs) ->
- returnRn (ArithSeqIn new_seq, fvs)
- where
- rn_seq (From expr)
- = rnExpr expr `thenRn` \ (expr', fvExpr) ->
- returnRn (From expr', fvExpr)
-
- rn_seq (FromThen expr1 expr2)
- = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
- rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
- returnRn (FromThen expr1' expr2', fvExpr1 `unionNameSets` fvExpr2)
-
- rn_seq (FromTo expr1 expr2)
- = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
- rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
- returnRn (FromTo expr1' expr2', fvExpr1 `unionNameSets` fvExpr2)
-
- rn_seq (FromThenTo expr1 expr2 expr3)
- = rnExpr expr1 `thenRn` \ (expr1', fvExpr1) ->
- rnExpr expr2 `thenRn` \ (expr2', fvExpr2) ->
- rnExpr expr3 `thenRn` \ (expr3', fvExpr3) ->
- returnRn (FromThenTo expr1' expr2' expr3',
- unionManyNameSets [fvExpr1, fvExpr2, fvExpr3])
+ = rnLExpr expr `thenM` \ (expr', fvExpr) ->
+ rnHsTypeFVs doc pty `thenM` \ (pty', fvTy) ->
+ returnM (ExprWithTySig expr' pty', fvExpr `plusFV` fvTy)
+ where
+ doc = text "In an expression type signature"
+
+rnExpr (HsIf p b1 b2)
+ = rnLExpr p `thenM` \ (p', fvP) ->
+ rnLExpr b1 `thenM` \ (b1', fvB1) ->
+ rnLExpr b2 `thenM` \ (b2', fvB2) ->
+ returnM (HsIf p' b1' b2', plusFVs [fvP, fvB1, fvB2])
+
+rnExpr (HsType a)
+ = rnHsTypeFVs doc a `thenM` \ (t, fvT) ->
+ returnM (HsType t, fvT)
+ where
+ doc = text "In a type argument"
+
+rnExpr (ArithSeq _ seq)
+ = rnArithSeq seq `thenM` \ (new_seq, fvs) ->
+ returnM (ArithSeq noPostTcExpr new_seq, fvs)
+
+rnExpr (PArrSeq _ seq)
+ = rnArithSeq seq `thenM` \ (new_seq, fvs) ->
+ returnM (PArrSeq noPostTcExpr new_seq, fvs)
+\end{code}
+
+These three are pattern syntax appearing in expressions.
+Since all the symbols are reservedops we can simply reject them.
+We return a (bogus) EWildPat in each case.
+
+\begin{code}
+rnExpr e@EWildPat = patSynErr e
+rnExpr e@(EAsPat {}) = patSynErr e
+rnExpr e@(ELazyPat {}) = patSynErr e
\end{code}
%************************************************************************
%* *
-\subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
+ Arrow notation
%* *
%************************************************************************
\begin{code}
-rnRbinds str rbinds
- = mapRn field_dup_err dup_fields `thenRn_`
- mapAndUnzipRn rn_rbind rbinds `thenRn` \ (rbinds', fvRbind_s) ->
- returnRn (rbinds', unionManyNameSets fvRbind_s)
+rnExpr (HsProc pat body)
+ = newArrowScope $
+ rnPatsAndThen ProcExpr [pat] $ \ [pat'] ->
+ rnCmdTop body `thenM` \ (body',fvBody) ->
+ returnM (HsProc pat' body', fvBody)
+
+rnExpr (HsArrApp arrow arg _ ho rtl)
+ = select_arrow_scope (rnLExpr arrow) `thenM` \ (arrow',fvArrow) ->
+ rnLExpr arg `thenM` \ (arg',fvArg) ->
+ returnM (HsArrApp arrow' arg' placeHolderType ho rtl,
+ fvArrow `plusFV` fvArg)
where
- (_, dup_fields) = removeDups cmp [ f | (f,_,_) <- rbinds ]
+ select_arrow_scope tc = case ho of
+ HsHigherOrderApp -> tc
+ HsFirstOrderApp -> escapeArrowScope tc
- field_dup_err dups = addErrRn (dupFieldErr str dups)
+-- infix form
+rnExpr (HsArrForm op (Just _) [arg1, arg2])
+ = escapeArrowScope (rnLExpr op)
+ `thenM` \ (op'@(L _ (HsVar op_name)),fv_op) ->
+ rnCmdTop arg1 `thenM` \ (arg1',fv_arg1) ->
+ rnCmdTop arg2 `thenM` \ (arg2',fv_arg2) ->
- rn_rbind (field, expr, pun)
- = lookupGlobalOccRn field `thenRn` \ fieldname ->
- rnExpr expr `thenRn` \ (expr', fvExpr) ->
- returnRn ((fieldname, expr', pun), fvExpr)
+ -- Deal with fixity
-rnRpats rpats
- = mapRn field_dup_err dup_fields `thenRn_`
- mapRn rn_rpat rpats
- where
- (_, dup_fields) = removeDups cmp [ f | (f,_,_) <- rpats ]
+ lookupFixityRn op_name `thenM` \ fixity ->
+ mkOpFormRn arg1' op' fixity arg2' `thenM` \ final_e ->
- field_dup_err dups = addErrRn (dupFieldErr "pattern" dups)
+ returnM (final_e,
+ fv_arg1 `plusFV` fv_op `plusFV` fv_arg2)
- rn_rpat (field, pat, pun)
- = lookupGlobalOccRn field `thenRn` \ fieldname ->
- rnPat pat `thenRn` \ pat' ->
- returnRn (fieldname, pat', pun)
+rnExpr (HsArrForm op fixity cmds)
+ = escapeArrowScope (rnLExpr op) `thenM` \ (op',fvOp) ->
+ rnCmdArgs cmds `thenM` \ (cmds',fvCmds) ->
+ returnM (HsArrForm op' fixity cmds', fvOp `plusFV` fvCmds)
+
+rnExpr other = pprPanic "rnExpr: unexpected expression" (ppr other)
+ -- DictApp, DictLam, TyApp, TyLam
\end{code}
+
%************************************************************************
%* *
-\subsubsection{@Stmt@s: in @do@ expressions}
+ Arrow commands
%* *
%************************************************************************
-Note that although some bound vars may appear in the free var set for
-the first qual, these will eventually be removed by the caller. For
-example, if we have @[p | r <- s, q <- r, p <- q]@, when doing
-@[q <- r, p <- q]@, the free var set for @q <- r@ will
-be @{r}@, and the free var set for the entire Quals will be @{r}@. This
-@r@ will be removed only when we finally return from examining all the
-Quals.
-
\begin{code}
-type RnExprTy s = RdrNameHsExpr -> RnMS s (RenamedHsExpr, FreeVars)
+rnCmdArgs [] = returnM ([], emptyFVs)
+rnCmdArgs (arg:args)
+ = rnCmdTop arg `thenM` \ (arg',fvArg) ->
+ rnCmdArgs args `thenM` \ (args',fvArgs) ->
+ returnM (arg':args', fvArg `plusFV` fvArgs)
+
+
+rnCmdTop = wrapLocFstM rnCmdTop'
+ where
+ rnCmdTop' (HsCmdTop cmd _ _ _)
+ = rnLExpr (convertOpFormsLCmd cmd) `thenM` \ (cmd', fvCmd) ->
+ let
+ cmd_names = [arrAName, composeAName, firstAName] ++
+ nameSetToList (methodNamesCmd (unLoc cmd'))
+ in
+ -- Generate the rebindable syntax for the monad
+ lookupSyntaxTable cmd_names `thenM` \ (cmd_names', cmd_fvs) ->
+
+ returnM (HsCmdTop cmd' [] placeHolderType cmd_names',
+ fvCmd `plusFV` cmd_fvs)
+
+---------------------------------------------------
+-- convert OpApp's in a command context to HsArrForm's
+
+convertOpFormsLCmd :: LHsCmd id -> LHsCmd id
+convertOpFormsLCmd = fmap convertOpFormsCmd
+
+convertOpFormsCmd :: HsCmd id -> HsCmd id
+
+convertOpFormsCmd (HsApp c e) = HsApp (convertOpFormsLCmd c) e
+convertOpFormsCmd (HsLam match) = HsLam (convertOpFormsMatch match)
+convertOpFormsCmd (OpApp c1 op fixity c2)
+ = let
+ arg1 = L (getLoc c1) $ HsCmdTop (convertOpFormsLCmd c1) [] placeHolderType []
+ arg2 = L (getLoc c2) $ HsCmdTop (convertOpFormsLCmd c2) [] placeHolderType []
+ in
+ HsArrForm op (Just fixity) [arg1, arg2]
-rnStmts :: RnExprTy s
- -> [RdrNameStmt]
- -> ([RenamedStmt] -> RnMS s (a, FreeVars))
- -> RnMS s (a, FreeVars)
+convertOpFormsCmd (HsPar c) = HsPar (convertOpFormsLCmd c)
-rnStmts rn_expr [] thing_inside
- = thing_inside []
+-- gaw 2004
+convertOpFormsCmd (HsCase exp matches)
+ = HsCase exp (convertOpFormsMatch matches)
-rnStmts rn_expr (stmt:stmts) thing_inside
- = rnStmt rn_expr stmt $ \ stmt' ->
- rnStmts rn_expr stmts $ \ stmts' ->
- thing_inside (stmt' : stmts')
+convertOpFormsCmd (HsIf exp c1 c2)
+ = HsIf exp (convertOpFormsLCmd c1) (convertOpFormsLCmd c2)
-rnStmt :: RnExprTy s -> RdrNameStmt -> (RenamedStmt -> RnMS s (a, FreeVars)) -> RnMS s (a, FreeVars)
--- Because of mutual recursion we have to pass in rnExpr.
+convertOpFormsCmd (HsLet binds cmd)
+ = HsLet binds (convertOpFormsLCmd cmd)
-rnStmt rn_expr (BindStmt pat expr src_loc) thing_inside
- = pushSrcLocRn src_loc $
- rn_expr expr `thenRn` \ (expr', fv_expr) ->
- bindLocalsRn "pattern in do binding" binders $ \ new_binders ->
- rnPat pat `thenRn` \ pat' ->
+convertOpFormsCmd (HsDo ctxt stmts body ty)
+ = HsDo ctxt (map (fmap convertOpFormsStmt) stmts)
+ (convertOpFormsLCmd body) ty
- thing_inside (BindStmt pat' expr' src_loc) `thenRn` \ (result, fvs) ->
- returnRn (result, fv_expr `unionNameSets` (fvs `minusNameSet` mkNameSet new_binders))
- where
- binders = collectPatBinders pat
-
-rnStmt rn_expr (ExprStmt expr src_loc) thing_inside
- = pushSrcLocRn src_loc $
- rn_expr expr `thenRn` \ (expr', fv_expr) ->
- thing_inside (ExprStmt expr' src_loc) `thenRn` \ (result, fvs) ->
- returnRn (result, fv_expr `unionNameSets` fvs)
-
-rnStmt rn_expr (GuardStmt expr src_loc) thing_inside
- = pushSrcLocRn src_loc $
- rn_expr expr `thenRn` \ (expr', fv_expr) ->
- thing_inside (GuardStmt expr' src_loc) `thenRn` \ (result, fvs) ->
- returnRn (result, fv_expr `unionNameSets` fvs)
-
-rnStmt rn_expr (ReturnStmt expr) thing_inside
- = rn_expr expr `thenRn` \ (expr', fv_expr) ->
- thing_inside (ReturnStmt expr') `thenRn` \ (result, fvs) ->
- returnRn (result, fv_expr `unionNameSets` fvs)
-
-rnStmt rn_expr (LetStmt binds) thing_inside
- = rnBinds binds $ \ binds' ->
- thing_inside (LetStmt binds')
-\end{code}
+-- Anything else is unchanged. This includes HsArrForm (already done),
+-- things with no sub-commands, and illegal commands (which will be
+-- caught by the type checker)
+convertOpFormsCmd c = c
-%************************************************************************
-%* *
-\subsubsection{Precedence Parsing}
-%* *
-%************************************************************************
+convertOpFormsStmt (BindStmt pat cmd _ _)
+ = BindStmt pat (convertOpFormsLCmd cmd) noSyntaxExpr noSyntaxExpr
+convertOpFormsStmt (ExprStmt cmd _ _)
+ = ExprStmt (convertOpFormsLCmd cmd) noSyntaxExpr placeHolderType
+convertOpFormsStmt (RecStmt stmts lvs rvs es binds)
+ = RecStmt (map (fmap convertOpFormsStmt) stmts) lvs rvs es binds
+convertOpFormsStmt stmt = stmt
-@mkOpAppRn@ deals with operator fixities. The argument expressions
-are assumed to be already correctly arranged. It needs the fixities
-recorded in the OpApp nodes, because fixity info applies to the things
-the programmer actually wrote, so you can't find it out from the Name.
+convertOpFormsMatch (MatchGroup ms ty)
+ = MatchGroup (map (fmap convert) ms) ty
+ where convert (Match pat mty grhss)
+ = Match pat mty (convertOpFormsGRHSs grhss)
-Furthermore, the second argument is guaranteed not to be another
-operator application. Why? Because the parser parses all
-operator appications left-associatively.
+convertOpFormsGRHSs (GRHSs grhss binds)
+ = GRHSs (map convertOpFormsGRHS grhss) binds
-\begin{code}
-mkOpAppRn :: RenamedHsExpr -> RenamedHsExpr -> Fixity -> RenamedHsExpr
- -> RnMS s RenamedHsExpr
-
-mkOpAppRn e1@(OpApp e11 op1 fix1 e12)
- op2 fix2 e2
- | nofix_error
- = addErrRn (precParseErr (get op1,fix1) (get op2,fix2)) `thenRn_`
- returnRn (OpApp e1 op2 fix2 e2)
-
- | rearrange_me
- = mkOpAppRn e12 op2 fix2 e2 `thenRn` \ new_e ->
- returnRn (OpApp e11 op1 fix1 new_e)
- where
- (nofix_error, rearrange_me) = compareFixity fix1 fix2
-
-mkOpAppRn e1@(NegApp neg_arg neg_op)
- op2
- fix2@(Fixity prec2 dir2)
- e2
- | nofix_error
- = addErrRn (precParseErr (get neg_op,fix_neg) (get op2,fix2)) `thenRn_`
- returnRn (OpApp e1 op2 fix2 e2)
-
- | rearrange_me
- = mkOpAppRn neg_arg op2 fix2 e2 `thenRn` \ new_e ->
- returnRn (NegApp new_e neg_op)
- where
- fix_neg = Fixity 6 InfixL -- Precedence of unary negate is wired in as infixl 6!
- (nofix_error, rearrange_me) = compareFixity fix_neg fix2
+convertOpFormsGRHS = fmap convert
+ where
+ convert (GRHS stmts cmd) = GRHS stmts (convertOpFormsLCmd cmd)
-mkOpAppRn e1 op fix e2 -- Default case, no rearrangment
- = ASSERT( right_op_ok fix e2 )
- returnRn (OpApp e1 op fix e2)
+---------------------------------------------------
+type CmdNeeds = FreeVars -- Only inhabitants are
+ -- appAName, choiceAName, loopAName
-get (HsVar n) = n
+-- find what methods the Cmd needs (loop, choice, apply)
+methodNamesLCmd :: LHsCmd Name -> CmdNeeds
+methodNamesLCmd = methodNamesCmd . unLoc
--- Parser left-associates everything, but
--- derived instances may have correctly-associated things to
--- in the right operarand. So we just check that the right operand is OK
-right_op_ok fix1 (OpApp _ _ fix2 _)
- = not error_please && associate_right
- where
- (error_please, associate_right) = compareFixity fix1 fix2
-right_op_ok fix1 other
- = True
-
--- Parser initially makes negation bind more tightly than any other operator
-mkNegAppRn neg_arg neg_op
- =
-#ifdef DEBUG
- getModeRn `thenRn` \ mode ->
- ASSERT( not_op_app mode neg_arg )
-#endif
- returnRn (NegApp neg_arg neg_op)
-
-not_op_app SourceMode (OpApp _ _ _ _) = False
-not_op_app mode other = True
-\end{code}
+methodNamesCmd :: HsCmd Name -> CmdNeeds
-\begin{code}
-mkConOpPatRn :: RenamedPat -> Name -> Fixity -> RenamedPat
- -> RnMS s RenamedPat
+methodNamesCmd cmd@(HsArrApp _arrow _arg _ HsFirstOrderApp _rtl)
+ = emptyFVs
+methodNamesCmd cmd@(HsArrApp _arrow _arg _ HsHigherOrderApp _rtl)
+ = unitFV appAName
+methodNamesCmd cmd@(HsArrForm {}) = emptyFVs
-mkConOpPatRn p1@(ConOpPatIn p11 op1 fix1 p12)
- op2 fix2 p2
- | nofix_error
- = addErrRn (precParseErr (op1,fix1) (op2,fix2)) `thenRn_`
- returnRn (ConOpPatIn p1 op2 fix2 p2)
+methodNamesCmd (HsPar c) = methodNamesLCmd c
- | rearrange_me
- = mkConOpPatRn p12 op2 fix2 p2 `thenRn` \ new_p ->
- returnRn (ConOpPatIn p11 op1 fix1 new_p)
+methodNamesCmd (HsIf p c1 c2)
+ = methodNamesLCmd c1 `plusFV` methodNamesLCmd c2 `addOneFV` choiceAName
- where
- (nofix_error, rearrange_me) = compareFixity fix1 fix2
-
-mkConOpPatRn p1@(NegPatIn neg_arg)
- op2
- fix2@(Fixity prec2 dir2)
- p2
- | prec2 > 6 -- Precedence of unary - is wired in as 6!
- = addErrRn (precParseNegPatErr (op2,fix2)) `thenRn_`
- returnRn (ConOpPatIn p1 op2 fix2 p2)
-
-mkConOpPatRn p1 op fix p2 -- Default case, no rearrangment
- = ASSERT( not_op_pat p2 )
- returnRn (ConOpPatIn p1 op fix p2)
-
-not_op_pat (ConOpPatIn _ _ _ _) = False
-not_op_pat other = True
+methodNamesCmd (HsLet b c) = methodNamesLCmd c
+
+methodNamesCmd (HsDo sc stmts body ty)
+ = methodNamesStmts stmts `plusFV` methodNamesLCmd body
+
+methodNamesCmd (HsApp c e) = methodNamesLCmd c
+
+methodNamesCmd (HsLam match) = methodNamesMatch match
+
+methodNamesCmd (HsCase scrut matches)
+ = methodNamesMatch matches `addOneFV` choiceAName
+
+methodNamesCmd other = emptyFVs
+ -- Other forms can't occur in commands, but it's not convenient
+ -- to error here so we just do what's convenient.
+ -- The type checker will complain later
+
+---------------------------------------------------
+methodNamesMatch (MatchGroup ms ty)
+ = plusFVs (map do_one ms)
+ where
+ do_one (L _ (Match pats sig_ty grhss)) = methodNamesGRHSs grhss
+
+-------------------------------------------------
+-- gaw 2004
+methodNamesGRHSs (GRHSs grhss binds) = plusFVs (map methodNamesGRHS grhss)
+
+-------------------------------------------------
+methodNamesGRHS (L _ (GRHS stmts rhs)) = methodNamesLCmd rhs
+
+---------------------------------------------------
+methodNamesStmts stmts = plusFVs (map methodNamesLStmt stmts)
+
+---------------------------------------------------
+methodNamesLStmt = methodNamesStmt . unLoc
+
+methodNamesStmt (ExprStmt cmd _ _) = methodNamesLCmd cmd
+methodNamesStmt (BindStmt pat cmd _ _) = methodNamesLCmd cmd
+methodNamesStmt (RecStmt stmts _ _ _ _)
+ = methodNamesStmts stmts `addOneFV` loopAName
+methodNamesStmt (LetStmt b) = emptyFVs
+methodNamesStmt (ParStmt ss) = emptyFVs
+ -- ParStmt can't occur in commands, but it's not convenient to error
+ -- here so we just do what's convenient
\end{code}
-\begin{code}
-checkPrecMatch :: Bool -> RdrName -> RdrNameMatch -> RnMS s ()
-
-checkPrecMatch False fn match
- = returnRn ()
-checkPrecMatch True op (PatMatch p1 (PatMatch p2 (GRHSMatch _)))
- = checkPrec op p1 False `thenRn_`
- checkPrec op p2 True
-checkPrecMatch True op _
- = panic "checkPrecMatch"
-
-checkPrec op (ConOpPatIn _ op1 _ _) right
- = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
- lookupFixity op1 `thenRn` \ op1_fix@(Fixity op1_prec op1_dir) ->
- let
- inf_ok = op1_prec > op_prec ||
- (op1_prec == op_prec &&
- (op1_dir == InfixR && op_dir == InfixR && right ||
- op1_dir == InfixL && op_dir == InfixL && not right))
-
- info = (op,op_fix)
- info1 = (op1,op1_fix)
- (infol, infor) = if right then (info, info1) else (info1, info)
- in
- checkRn inf_ok (precParseErr infol infor)
-checkPrec op (NegPatIn _) right
- = lookupFixity op `thenRn` \ op_fix@(Fixity op_prec op_dir) ->
- checkRn (op_prec <= 6) (precParseNegPatErr (op,op_fix))
+%************************************************************************
+%* *
+ Arithmetic sequences
+%* *
+%************************************************************************
-checkPrec op pat right
- = returnRn ()
+\begin{code}
+rnArithSeq (From expr)
+ = rnLExpr expr `thenM` \ (expr', fvExpr) ->
+ returnM (From expr', fvExpr)
+
+rnArithSeq (FromThen expr1 expr2)
+ = rnLExpr expr1 `thenM` \ (expr1', fvExpr1) ->
+ rnLExpr expr2 `thenM` \ (expr2', fvExpr2) ->
+ returnM (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2)
+
+rnArithSeq (FromTo expr1 expr2)
+ = rnLExpr expr1 `thenM` \ (expr1', fvExpr1) ->
+ rnLExpr expr2 `thenM` \ (expr2', fvExpr2) ->
+ returnM (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2)
+
+rnArithSeq (FromThenTo expr1 expr2 expr3)
+ = rnLExpr expr1 `thenM` \ (expr1', fvExpr1) ->
+ rnLExpr expr2 `thenM` \ (expr2', fvExpr2) ->
+ rnLExpr expr3 `thenM` \ (expr3', fvExpr3) ->
+ returnM (FromThenTo expr1' expr2' expr3',
+ plusFVs [fvExpr1, fvExpr2, fvExpr3])
\end{code}
-Consider
- a `op1` b `op2` c
-(compareFixity op1 op2) tells which way to arrange appication, or
-whether there's an error.
+%************************************************************************
+%* *
+\subsubsection{@Rbinds@s and @Rpats@s: in record expressions}
+%* *
+%************************************************************************
\begin{code}
-compareFixity :: Fixity -> Fixity
- -> (Bool, -- Error please
- Bool) -- Associate to the right: a op1 (b op2 c)
-compareFixity (Fixity prec1 dir1) (Fixity prec2 dir2)
- = case prec1 `cmp` prec2 of
- GT_ -> left
- LT_ -> right
- EQ_ -> case (dir1, dir2) of
- (InfixR, InfixR) -> right
- (InfixL, InfixL) -> left
- _ -> error_please
+rnRbinds str rbinds
+ = mappM_ field_dup_err dup_fields `thenM_`
+ mapFvRn rn_rbind rbinds `thenM` \ (rbinds', fvRbind) ->
+ returnM (rbinds', fvRbind)
where
- right = (False, True)
- left = (False, False)
- error_please = (True, False)
+ (_, dup_fields) = removeDups cmpLocated [ f | (f,_) <- rbinds ]
+
+ field_dup_err dups = mappM_ (\f -> addLocErr f (dupFieldErr str)) dups
+
+ rn_rbind (field, expr)
+ = lookupLocatedGlobalOccRn field `thenM` \ fieldname ->
+ rnLExpr expr `thenM` \ (expr', fvExpr) ->
+ returnM ((fieldname, expr'), fvExpr `addOneFV` unLoc fieldname)
\end{code}
%************************************************************************
%* *
-\subsubsection{Literals}
+ Template Haskell brackets
%* *
%************************************************************************
-When literals occur we have to make sure that the types and classes they involve
-are made available.
+\begin{code}
+rnBracket (VarBr n) = do { name <- lookupOccRn n
+ ; this_mod <- getModule
+ ; checkM (nameIsLocalOrFrom this_mod name) $ -- Reason: deprecation checking asumes the
+ do { loadHomeInterface msg name -- home interface is loaded, and this is the
+ ; return () } -- only way that is going to happen
+ ; returnM (VarBr name, unitFV name) }
+ where
+ msg = ptext SLIT("Need interface for Template Haskell quoted Name")
+
+rnBracket (ExpBr e) = do { (e', fvs) <- rnLExpr e
+ ; return (ExpBr e', fvs) }
+rnBracket (PatBr p) = do { (p', fvs) <- rnLPat p
+ ; return (PatBr p', fvs) }
+rnBracket (TypBr t) = do { (t', fvs) <- rnHsTypeFVs doc t
+ ; return (TypBr t', fvs) }
+ where
+ doc = ptext SLIT("In a Template-Haskell quoted type")
+rnBracket (DecBr group)
+ = do { gbl_env <- getGblEnv
+
+ ; let gbl_env1 = gbl_env { tcg_mod = thFAKE }
+ -- Note the thFAKE. The top-level names from the bracketed
+ -- declarations will go into the name cache, and we don't want them to
+ -- confuse the Names for the current module.
+ -- By using a pretend module, thFAKE, we keep them safely out of the way.
+
+ ; names <- getLocalDeclBinders gbl_env1 group
+ ; rdr_env' <- extendRdrEnvRn emptyGlobalRdrEnv names
+ -- Furthermore, the names in the bracket shouldn't conflict with
+ -- existing top-level names E.g.
+ -- foo = 1
+ -- bar = [d| foo = 1|]
+ -- But both 'foo's get a LocalDef provenance, so we'd get a complaint unless
+ -- we start with an emptyGlobalRdrEnv
+
+ ; setGblEnv (gbl_env { tcg_rdr_env = tcg_rdr_env gbl_env1 `plusOccEnv` rdr_env',
+ tcg_dus = emptyDUs }) $ do
+ -- Notice plusOccEnv, not plusGlobalRdrEnv. In this situation we want
+ -- to *shadow* top-level bindings. (See the 'foo' example above.)
+ -- If we don't shadow, we'll get an ambiguity complaint when we do
+ -- a lookupTopBndrRn (which uses lookupGreLocalRn) on the binder of the 'foo'
+ --
+ -- Furthermore, arguably if the splice does define foo, that should hide
+ -- any foo's further out
+ --
+ -- The emptyDUs is so that we just collect uses for this group alone
+
+ { (tcg_env, group') <- rnSrcDecls group
+ -- Discard the tcg_env; it contains only extra info about fixity
+ ; return (DecBr group', allUses (tcg_dus tcg_env)) } }
+\end{code}
+
+%************************************************************************
+%* *
+\subsubsection{@Stmt@s: in @do@ expressions}
+%* *
+%************************************************************************
\begin{code}
-litOccurrence (HsChar _)
- = addImplicitOccRn charType_name
+rnStmts :: HsStmtContext Name -> [LStmt RdrName]
+ -> RnM (thing, FreeVars)
+ -> RnM (([LStmt Name], thing), FreeVars)
+
+rnStmts (MDoExpr _) = rnMDoStmts
+rnStmts ctxt = rnNormalStmts ctxt
+
+rnNormalStmts :: HsStmtContext Name -> [LStmt RdrName]
+ -> RnM (thing, FreeVars)
+ -> RnM (([LStmt Name], thing), FreeVars)
+-- Used for cases *other* than recursive mdo
+-- Implements nested scopes
+
+rnNormalStmts ctxt [] thing_inside
+ = do { (thing, fvs) <- thing_inside
+ ; return (([],thing), fvs) }
+
+rnNormalStmts ctxt (L loc stmt : stmts) thing_inside
+ = do { ((stmt', (stmts', thing)), fvs)
+ <- rnStmt ctxt stmt $
+ rnNormalStmts ctxt stmts thing_inside
+ ; return (((L loc stmt' : stmts'), thing), fvs) }
+
+rnStmt :: HsStmtContext Name -> Stmt RdrName
+ -> RnM (thing, FreeVars)
+ -> RnM ((Stmt Name, thing), FreeVars)
+
+rnStmt ctxt (ExprStmt expr _ _) thing_inside
+ = do { (expr', fv_expr) <- rnLExpr expr
+ ; (then_op, fvs1) <- lookupSyntaxName thenMName
+ ; (thing, fvs2) <- thing_inside
+ ; return ((ExprStmt expr' then_op placeHolderType, thing),
+ fv_expr `plusFV` fvs1 `plusFV` fvs2) }
+
+rnStmt ctxt (BindStmt pat expr _ _) thing_inside
+ = do { (expr', fv_expr) <- rnLExpr expr
+ -- The binders do not scope over the expression
+ ; (bind_op, fvs1) <- lookupSyntaxName bindMName
+ ; (fail_op, fvs2) <- lookupSyntaxName failMName
+ ; rnPatsAndThen (StmtCtxt ctxt) [pat] $ \ [pat'] -> do
+ { (thing, fvs3) <- thing_inside
+ ; return ((BindStmt pat' expr' bind_op fail_op, thing),
+ fv_expr `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) }}
+ -- fv_expr shouldn't really be filtered by the rnPatsAndThen
+ -- but it does not matter because the names are unique
+
+rnStmt ctxt (LetStmt binds) thing_inside
+ = do { checkErr (ok ctxt binds)
+ (badIpBinds (ptext SLIT("a parallel list comprehension:")) binds)
+ ; rnLocalBindsAndThen binds $ \ binds' -> do
+ { (thing, fvs) <- thing_inside
+ ; return ((LetStmt binds', thing), fvs) }}
+ where
+ -- We do not allow implicit-parameter bindings in a parallel
+ -- list comprehension. I'm not sure what it might mean.
+ ok (ParStmtCtxt _) (HsIPBinds _) = False
+ ok _ _ = True
+
+rnStmt ctxt (RecStmt rec_stmts _ _ _ _) thing_inside
+ = bindLocatedLocalsRn doc (collectLStmtsBinders rec_stmts) $ \ bndrs ->
+ rn_rec_stmts bndrs rec_stmts `thenM` \ segs ->
+ thing_inside `thenM` \ (thing, fvs) ->
+ let
+ segs_w_fwd_refs = addFwdRefs segs
+ (ds, us, fs, rec_stmts') = unzip4 segs_w_fwd_refs
+ later_vars = nameSetToList (plusFVs ds `intersectNameSet` fvs)
+ fwd_vars = nameSetToList (plusFVs fs)
+ uses = plusFVs us
+ rec_stmt = RecStmt rec_stmts' later_vars fwd_vars [] emptyLHsBinds
+ in
+ returnM ((rec_stmt, thing), uses `plusFV` fvs)
+ where
+ doc = text "In a recursive do statement"
+
+rnStmt ctxt (ParStmt segs) thing_inside
+ = do { opt_GlasgowExts <- doptM Opt_GlasgowExts
+ ; checkM opt_GlasgowExts parStmtErr
+ ; orig_lcl_env <- getLocalRdrEnv
+ ; ((segs',thing), fvs) <- go orig_lcl_env [] segs
+ ; return ((ParStmt segs', thing), fvs) }
+ where
+-- type ParSeg id = [([LStmt id], [id])]
+-- go :: NameSet -> [ParSeg RdrName]
+-- -> RnM (([ParSeg Name], thing), FreeVars)
+
+ go orig_lcl_env bndrs []
+ = do { let { (bndrs', dups) = removeDups cmpByOcc bndrs
+ ; inner_env = extendLocalRdrEnv orig_lcl_env bndrs' }
+ ; mappM dupErr dups
+ ; (thing, fvs) <- setLocalRdrEnv inner_env thing_inside
+ ; return (([], thing), fvs) }
+
+ go orig_lcl_env bndrs_so_far ((stmts, _) : segs)
+ = do { ((stmts', (bndrs, segs', thing)), fvs)
+ <- rnNormalStmts par_ctxt stmts $ do
+ { -- Find the Names that are bound by stmts
+ lcl_env <- getLocalRdrEnv
+ ; let { rdr_bndrs = collectLStmtsBinders stmts
+ ; bndrs = map ( fromJust
+ . lookupLocalRdrEnv lcl_env
+ . unLoc) rdr_bndrs
+ ; new_bndrs = nub bndrs ++ bndrs_so_far
+ -- The nub is because there might be shadowing
+ -- x <- e1; x <- e2
+ -- So we'll look up (Unqual x) twice, getting
+ -- the second binding both times, which is the
+ } -- one we want
+
+ -- Typecheck the thing inside, passing on all
+ -- the Names bound, but separately; revert the envt
+ ; ((segs', thing), fvs) <- setLocalRdrEnv orig_lcl_env $
+ go orig_lcl_env new_bndrs segs
+
+ -- Figure out which of the bound names are used
+ ; let used_bndrs = filter (`elemNameSet` fvs) bndrs
+ ; return ((used_bndrs, segs', thing), fvs) }
+
+ ; let seg' = (stmts', bndrs)
+ ; return (((seg':segs'), thing),
+ delListFromNameSet fvs bndrs) }
+
+ par_ctxt = ParStmtCtxt ctxt
+
+ cmpByOcc n1 n2 = nameOccName n1 `compare` nameOccName n2
+ dupErr vs = addErr (ptext SLIT("Duplicate binding in parallel list comprehension for:")
+ <+> quotes (ppr (head vs)))
+\end{code}
-litOccurrence (HsCharPrim _)
- = addImplicitOccRn (getName charPrimTyCon)
-litOccurrence (HsString _)
- = addImplicitOccRn listType_name `thenRn_`
- addImplicitOccRn charType_name
+%************************************************************************
+%* *
+\subsubsection{mdo expressions}
+%* *
+%************************************************************************
-litOccurrence (HsStringPrim _)
- = addImplicitOccRn (getName addrPrimTyCon)
+\begin{code}
+type FwdRefs = NameSet
+type Segment stmts = (Defs,
+ Uses, -- May include defs
+ FwdRefs, -- A subset of uses that are
+ -- (a) used before they are bound in this segment, or
+ -- (b) used here, and bound in subsequent segments
+ stmts) -- Either Stmt or [Stmt]
+
+
+----------------------------------------------------
+rnMDoStmts :: [LStmt RdrName]
+ -> RnM (thing, FreeVars)
+ -> RnM (([LStmt Name], thing), FreeVars)
+rnMDoStmts stmts thing_inside
+ = -- Step1: bring all the binders of the mdo into scope
+ -- Remember that this also removes the binders from the
+ -- finally-returned free-vars
+ bindLocatedLocalsRn doc (collectLStmtsBinders stmts) $ \ bndrs ->
+ do {
+ -- Step 2: Rename each individual stmt, making a
+ -- singleton segment. At this stage the FwdRefs field
+ -- isn't finished: it's empty for all except a BindStmt
+ -- for which it's the fwd refs within the bind itself
+ -- (This set may not be empty, because we're in a recursive
+ -- context.)
+ segs <- rn_rec_stmts bndrs stmts
+
+ ; (thing, fvs_later) <- thing_inside
+
+ ; let
+ -- Step 3: Fill in the fwd refs.
+ -- The segments are all singletons, but their fwd-ref
+ -- field mentions all the things used by the segment
+ -- that are bound after their use
+ segs_w_fwd_refs = addFwdRefs segs
+
+ -- Step 4: Group together the segments to make bigger segments
+ -- Invariant: in the result, no segment uses a variable
+ -- bound in a later segment
+ grouped_segs = glomSegments segs_w_fwd_refs
+
+ -- Step 5: Turn the segments into Stmts
+ -- Use RecStmt when and only when there are fwd refs
+ -- Also gather up the uses from the end towards the
+ -- start, so we can tell the RecStmt which things are
+ -- used 'after' the RecStmt
+ (stmts', fvs) = segsToStmts grouped_segs fvs_later
+
+ ; return ((stmts', thing), fvs) }
+ where
+ doc = text "In a recursive mdo-expression"
+
+---------------------------------------------
+rn_rec_stmts :: [Name] -> [LStmt RdrName] -> RnM [Segment (LStmt Name)]
+rn_rec_stmts bndrs stmts = mappM (rn_rec_stmt bndrs) stmts `thenM` \ segs_s ->
+ returnM (concat segs_s)
+
+----------------------------------------------------
+rn_rec_stmt :: [Name] -> LStmt RdrName -> RnM [Segment (LStmt Name)]
+ -- Rename a Stmt that is inside a RecStmt (or mdo)
+ -- Assumes all binders are already in scope
+ -- Turns each stmt into a singleton Stmt
+
+rn_rec_stmt all_bndrs (L loc (ExprStmt expr _ _))
+ = rnLExpr expr `thenM` \ (expr', fvs) ->
+ lookupSyntaxName thenMName `thenM` \ (then_op, fvs1) ->
+ returnM [(emptyNameSet, fvs `plusFV` fvs1, emptyNameSet,
+ L loc (ExprStmt expr' then_op placeHolderType))]
+
+rn_rec_stmt all_bndrs (L loc (BindStmt pat expr _ _))
+ = rnLExpr expr `thenM` \ (expr', fv_expr) ->
+ rnLPat pat `thenM` \ (pat', fv_pat) ->
+ lookupSyntaxName bindMName `thenM` \ (bind_op, fvs1) ->
+ lookupSyntaxName failMName `thenM` \ (fail_op, fvs2) ->
+ let
+ bndrs = mkNameSet (collectPatBinders pat')
+ fvs = fv_expr `plusFV` fv_pat `plusFV` fvs1 `plusFV` fvs2
+ in
+ returnM [(bndrs, fvs, bndrs `intersectNameSet` fvs,
+ L loc (BindStmt pat' expr' bind_op fail_op))]
-litOccurrence (HsInt _)
- = lookupImplicitOccRn numClass_RDR -- Int and Integer are forced in by Num
+rn_rec_stmt all_bndrs (L loc (LetStmt binds@(HsIPBinds _)))
+ = do { addErr (badIpBinds (ptext SLIT("an mdo expression")) binds)
+ ; failM }
-litOccurrence (HsFrac _)
- = lookupImplicitOccRn fractionalClass_RDR `thenRn_`
- lookupImplicitOccRn ratioDataCon_RDR
- -- We have to make sure that the Ratio type is imported with
- -- its constructor, because literals of type Ratio t are
- -- built with that constructor.
-
-litOccurrence (HsIntPrim _)
- = addImplicitOccRn (getName intPrimTyCon)
+rn_rec_stmt all_bndrs (L loc (LetStmt (HsValBinds binds)))
+ = rnValBinds (trimWith all_bndrs) binds `thenM` \ (binds', du_binds) ->
+ returnM [(duDefs du_binds, duUses du_binds,
+ emptyNameSet, L loc (LetStmt (HsValBinds binds')))]
-litOccurrence (HsFloatPrim _)
- = addImplicitOccRn (getName floatPrimTyCon)
+rn_rec_stmt all_bndrs (L loc (RecStmt stmts _ _ _ _)) -- Flatten Rec inside Rec
+ = rn_rec_stmts all_bndrs stmts
-litOccurrence (HsDoublePrim _)
- = addImplicitOccRn (getName doublePrimTyCon)
+rn_rec_stmt all_bndrs stmt@(L _ (ParStmt _)) -- Syntactically illegal in mdo
+ = pprPanic "rn_rec_stmt" (ppr stmt)
-litOccurrence (HsLitLit _)
- = lookupImplicitOccRn ccallableClass_RDR
+---------------------------------------------
+addFwdRefs :: [Segment a] -> [Segment a]
+-- So far the segments only have forward refs *within* the Stmt
+-- (which happens for bind: x <- ...x...)
+-- This function adds the cross-seg fwd ref info
+
+addFwdRefs pairs
+ = fst (foldr mk_seg ([], emptyNameSet) pairs)
+ where
+ mk_seg (defs, uses, fwds, stmts) (segs, later_defs)
+ = (new_seg : segs, all_defs)
+ where
+ new_seg = (defs, uses, new_fwds, stmts)
+ all_defs = later_defs `unionNameSets` defs
+ new_fwds = fwds `unionNameSets` (uses `intersectNameSet` later_defs)
+ -- Add the downstream fwd refs here
+
+----------------------------------------------------
+-- Glomming the singleton segments of an mdo into
+-- minimal recursive groups.
+--
+-- At first I thought this was just strongly connected components, but
+-- there's an important constraint: the order of the stmts must not change.
+--
+-- Consider
+-- mdo { x <- ...y...
+-- p <- z
+-- y <- ...x...
+-- q <- x
+-- z <- y
+-- r <- x }
+--
+-- Here, the first stmt mention 'y', which is bound in the third.
+-- But that means that the innocent second stmt (p <- z) gets caught
+-- up in the recursion. And that in turn means that the binding for
+-- 'z' has to be included... and so on.
+--
+-- Start at the tail { r <- x }
+-- Now add the next one { z <- y ; r <- x }
+-- Now add one more { q <- x ; z <- y ; r <- x }
+-- Now one more... but this time we have to group a bunch into rec
+-- { rec { y <- ...x... ; q <- x ; z <- y } ; r <- x }
+-- Now one more, which we can add on without a rec
+-- { p <- z ;
+-- rec { y <- ...x... ; q <- x ; z <- y } ;
+-- r <- x }
+-- Finally we add the last one; since it mentions y we have to
+-- glom it togeher with the first two groups
+-- { rec { x <- ...y...; p <- z ; y <- ...x... ;
+-- q <- x ; z <- y } ;
+-- r <- x }
+
+glomSegments :: [Segment (LStmt Name)] -> [Segment [LStmt Name]]
+
+glomSegments [] = []
+glomSegments ((defs,uses,fwds,stmt) : segs)
+ -- Actually stmts will always be a singleton
+ = (seg_defs, seg_uses, seg_fwds, seg_stmts) : others
+ where
+ segs' = glomSegments segs
+ (extras, others) = grab uses segs'
+ (ds, us, fs, ss) = unzip4 extras
+
+ seg_defs = plusFVs ds `plusFV` defs
+ seg_uses = plusFVs us `plusFV` uses
+ seg_fwds = plusFVs fs `plusFV` fwds
+ seg_stmts = stmt : concat ss
+
+ grab :: NameSet -- The client
+ -> [Segment a]
+ -> ([Segment a], -- Needed by the 'client'
+ [Segment a]) -- Not needed by the client
+ -- The result is simply a split of the input
+ grab uses dus
+ = (reverse yeses, reverse noes)
+ where
+ (noes, yeses) = span not_needed (reverse dus)
+ not_needed (defs,_,_,_) = not (intersectsNameSet defs uses)
+
+
+----------------------------------------------------
+segsToStmts :: [Segment [LStmt Name]]
+ -> FreeVars -- Free vars used 'later'
+ -> ([LStmt Name], FreeVars)
+
+segsToStmts [] fvs_later = ([], fvs_later)
+segsToStmts ((defs, uses, fwds, ss) : segs) fvs_later
+ = ASSERT( not (null ss) )
+ (new_stmt : later_stmts, later_uses `plusFV` uses)
+ where
+ (later_stmts, later_uses) = segsToStmts segs fvs_later
+ new_stmt | non_rec = head ss
+ | otherwise = L (getLoc (head ss)) $
+ RecStmt ss (nameSetToList used_later) (nameSetToList fwds)
+ [] emptyLHsBinds
+ where
+ non_rec = isSingleton ss && isEmptyNameSet fwds
+ used_later = defs `intersectNameSet` later_uses
+ -- The ones needed after the RecStmt
\end{code}
+%************************************************************************
+%* *
+\subsubsection{Assertion utils}
+%* *
+%************************************************************************
+
+\begin{code}
+mkAssertErrorExpr :: RnM (HsExpr Name, FreeVars)
+-- Return an expression for (assertError "Foo.hs:27")
+mkAssertErrorExpr
+ = getSrcSpanM `thenM` \ sloc ->
+ let
+ expr = HsApp (L sloc (HsVar assertErrorName)) (L sloc (HsLit msg))
+ msg = HsStringPrim (mkFastString (showSDoc (ppr sloc)))
+ in
+ returnM (expr, emptyFVs)
+\end{code}
%************************************************************************
%* *
%************************************************************************
\begin{code}
-dupFieldErr str (dup:rest) sty
- = hcat [ptext SLIT("duplicate field name `"),
- ppr sty dup,
- ptext SLIT("' in record "), text str]
-
-negPatErr pat sty
- = sep [ptext SLIT("prefix `-' not applied to literal in pattern"), ppr sty pat]
-
-precParseNegPatErr op sty
- = hang (ptext SLIT("precedence parsing error"))
- 4 (hcat [ptext SLIT("prefix `-' has lower precedence than "),
- pp_op sty op,
- ptext SLIT(" in pattern")])
-
-precParseErr op1 op2 sty
- = hang (ptext SLIT("precedence parsing error"))
- 4 (hcat [ptext SLIT("cannot mix "), pp_op sty op1, ptext SLIT(" and "), pp_op sty op2,
- ptext SLIT(" in the same infix expression")])
-
-nonStdGuardErr guard sty
- = hang (ptext SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)"))
- 4 (ppr sty guard)
-
-pp_op sty (op, fix) = hcat [ppr sty op, space, parens (ppr sty fix)]
+patSynErr e = do { addErr (sep [ptext SLIT("Pattern syntax in expression context:"),
+ nest 4 (ppr e)])
+ ; return (EWildPat, emptyFVs) }
+
+parStmtErr = addErr (ptext SLIT("Illegal parallel list comprehension: use -fglasgow-exts"))
+
+badIpBinds what binds
+ = hang (ptext SLIT("Implicit-parameter bindings illegal in") <+> what)
+ 2 (ppr binds)
\end{code}