2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[CodeGen]{@CodeGen@: main module of the code generator}
6 This module says how things get going at the top level.
8 @codeGen@ is the interface to the outside world. The \tr{cgTop*}
9 functions drive the mangling of top-level bindings.
11 %************************************************************************
13 \subsection[codeGen-outside-interface]{The code generator's offering to the world}
15 %************************************************************************
18 module CodeGen ( codeGen ) where
20 #include "HsVersions.h"
22 -- Kludge (??) so that CgExpr is reached via at least one non-SOURCE
23 -- import. Before, that wasn't the case, and CM therefore didn't
24 -- bother to compile it.
25 import CgExpr ( {-NOTHING!-} ) -- DO NOT DELETE THIS IMPORT
27 import DriverState ( v_Build_tag )
31 import PrelNames ( gHC_PRIM )
32 import CLabel ( mkSRTLabel, mkClosureLabel,
33 mkPlainModuleInitLabel, mkModuleInitLabel )
34 import PprAbsC ( dumpRealC )
35 import AbsCUtils ( mkAbstractCs, flattenAbsC )
36 import CgBindery ( CgIdInfo, addBindC, addBindsC, getCAddrModeAndInfo )
37 import CgClosure ( cgTopRhsClosure )
38 import CgCon ( cgTopRhsCon )
39 import CgConTbls ( genStaticConBits )
40 import ClosureInfo ( mkClosureLFInfo )
41 import CmdLineOpts ( DynFlags, DynFlag(..),
42 opt_SccProfilingOn, opt_EnsureSplittableC )
43 import HscTypes ( ForeignStubs(..), TypeEnv, typeEnvTyCons )
44 import CostCentre ( CollectedCCs )
45 import Id ( Id, idName, setIdName )
46 import Name ( nameSrcLoc, nameOccName, nameUnique, isInternalName, mkExternalName )
47 import OccName ( mkLocalOcc )
48 import PrimRep ( PrimRep(..) )
49 import TyCon ( isDataTyCon )
50 import Module ( Module )
51 import BasicTypes ( TopLevelFlag(..) )
52 import UniqSupply ( mkSplitUniqSupply )
53 import ErrUtils ( dumpIfSet_dyn, showPass )
54 import Panic ( assertPanic )
60 import DATA_IOREF ( readIORef )
68 -> [Module] -- directly-imported modules
69 -> CollectedCCs -- (Local/global) cost-centres needing declaring/registering.
70 -> [(StgBinding,[(Id,[Id])])] -- Bindings to convert, with SRTs
71 -> IO AbstractC -- Output
73 codeGen dflags this_mod type_env foreign_stubs imported_mods
74 cost_centre_info stg_binds
76 showPass dflags "CodeGen"
77 fl_uniqs <- mkSplitUniqSupply 'f'
78 way <- readIORef v_Build_tag
81 tycons = typeEnvTyCons type_env
82 data_tycons = filter isDataTyCon tycons
84 mapM_ (\x -> seq x (return ())) data_tycons
88 cinfo = MkCompInfo this_mod
90 datatype_stuff = genStaticConBits cinfo data_tycons
91 code_stuff = initC cinfo (mapCs cgTopBinding stg_binds)
92 init_stuff = mkModuleInit way cost_centre_info this_mod
93 foreign_stubs imported_mods
95 abstractC = mkAbstractCs [ maybeSplitCode,
99 -- Put datatype_stuff after code_stuff, because the
100 -- datatype closure table (for enumeration types) to
101 -- (say) PrelBase_True_closure, which is defined in
104 dumpIfSet_dyn dflags Opt_D_dump_absC "Abstract C" (dumpRealC abstractC)
106 return $! flattenAbsC fl_uniqs abstractC
109 %************************************************************************
111 \subsection[codegen-init]{Module initialisation code}
113 %************************************************************************
117 :: String -- the "way"
118 -> CollectedCCs -- cost centre info
123 mkModuleInit way cost_centre_info this_mod foreign_stubs imported_mods
125 (cc_decls, cc_regs) = mkCostCentreStuff cost_centre_info
127 register_foreign_exports
128 = case foreign_stubs of
130 ForeignStubs _ _ _ fe_bndrs -> map mk_export_register fe_bndrs
132 mk_export_register bndr
133 = CMacroStmt REGISTER_FOREIGN_EXPORT [lbl]
135 lbl = CLbl (mkClosureLabel (idName bndr)) PtrRep
136 -- we don't want/need to init GHC.Prim, so filter it out
138 mk_import_register mod
139 | mod == gHC_PRIM = AbsCNop
140 | otherwise = CMacroStmt REGISTER_IMPORT [
141 CLbl (mkModuleInitLabel mod way) AddrRep
144 register_mod_imports = map mk_import_register imported_mods
148 CModuleInitBlock (mkPlainModuleInitLabel this_mod)
149 (mkModuleInitLabel this_mod way)
150 (mkAbstractCs (register_foreign_exports ++
152 register_mod_imports))
156 Cost-centre profiling: Besides the usual stuff, we must produce
157 declarations for the cost-centres defined in this module;
159 (The local cost-centres involved in this are passed into the
163 mkCostCentreStuff (local_CCs, extern_CCs, singleton_CCSs)
164 | not opt_SccProfilingOn = (AbsCNop, AbsCNop)
167 map (CCostCentreDecl True) local_CCs ++
168 map (CCostCentreDecl False) extern_CCs ++
169 map CCostCentreStackDecl singleton_CCSs),
170 mkAbstractCs (mkCcRegister local_CCs singleton_CCSs)
173 mkCcRegister ccs cc_stacks
175 register_ccs = mkAbstractCs (map mk_register ccs)
176 register_cc_stacks = mkAbstractCs (map mk_register_ccs cc_stacks)
178 [ register_ccs, register_cc_stacks ]
181 = CCallProfCCMacro FSLIT("REGISTER_CC") [mkCCostCentre cc]
184 = CCallProfCCMacro FSLIT("REGISTER_CCS") [mkCCostCentreStack ccs]
187 %************************************************************************
189 \subsection[codegen-top-bindings]{Converting top-level STG bindings}
191 %************************************************************************
193 @cgTopBinding@ is only used for top-level bindings, since they need
194 to be allocated statically (not in the heap) and need to be labelled.
195 No unboxed bindings can happen at top level.
197 In the code below, the static bindings are accumulated in the
198 @MkCgState@, and transferred into the ``statics'' slot by @forkStatics@.
199 This is so that we can write the top level processing in a compositional
200 style, with the increasing static environment being plumbed as a state
204 cgTopBinding :: (StgBinding,[(Id,[Id])]) -> Code
205 cgTopBinding (StgNonRec id rhs, srts)
206 = absC maybeSplitCode `thenC`
207 maybeExternaliseId id `thenFC` \ id' ->
208 mapM_ (mkSRT [id']) srts `thenC`
209 cgTopRhs id' rhs `thenFC` \ (id, info) ->
210 addBindC id info `thenC`
211 -- Add the un-externalised Id to the envt, so we
212 -- find it when we look up occurrences
215 cgTopBinding (StgRec pairs, srts)
216 = absC maybeSplitCode `thenC`
218 (bndrs, rhss) = unzip pairs
220 mapFCs maybeExternaliseId bndrs `thenFC` \ bndrs' ->
222 pairs' = zip bndrs' rhss
224 mapM_ (mkSRT bndrs') srts `thenC`
226 addBindsC new_binds `thenC`
227 mapFCs ( \ (b,e) -> cgTopRhs b e ) pairs'
228 ) `thenFC` \ new_binds ->
231 mkSRT :: [Id] -> (Id,[Id]) -> Code
232 mkSRT these (id,[]) = nopC
234 = mapFCs remap ids `thenFC` \ ids ->
235 remap id `thenFC` \ id ->
236 absC (CSRT (mkSRTLabel (idName id)) (map (mkClosureLabel . idName) ids))
238 -- sigh, better map all the ids against the environment in case they've
239 -- been externalised (see maybeExternaliseId below).
240 remap id = case filter (==id) these of
241 [] -> getCAddrModeAndInfo id
242 `thenFC` \ (id, _, _) -> returnFC id
243 (id':_) -> returnFC id'
245 -- Urgh! I tried moving the forkStatics call from the rhss of cgTopRhs
246 -- to enclose the listFCs in cgTopBinding, but that tickled the
247 -- statics "error" call in initC. I DON'T UNDERSTAND WHY!
249 cgTopRhs :: Id -> StgRhs -> FCode (Id, CgIdInfo)
250 -- The Id is passed along for setting up a binding...
251 -- It's already been externalised if necessary
253 cgTopRhs bndr (StgRhsCon cc con args)
254 = forkStatics (cgTopRhsCon bndr con args)
256 cgTopRhs bndr (StgRhsClosure cc bi fvs upd_flag srt args body)
257 = ASSERT(null fvs) -- There should be no free variables
259 srt_label = mkSRTLabel (idName bndr)
260 lf_info = mkClosureLFInfo bndr TopLevel [{-no fvs-}] upd_flag args
262 setSRTLabel srt_label $
263 forkStatics (cgTopRhsClosure bndr cc bi srt args body lf_info)
267 %************************************************************************
269 \subsection{Stuff to support splitting}
271 %************************************************************************
273 If we're splitting the object, we need to externalise all the top-level names
274 (and then make sure we only use the externalised one in any C label we use
275 which refers to this name).
278 maybeExternaliseId :: Id -> FCode Id
279 maybeExternaliseId id
280 | opt_EnsureSplittableC, -- Externalise the name for -split-objs
282 = moduleName `thenFC` \ mod ->
283 returnFC (setIdName id (mkExternalName uniq mod new_occ (nameSrcLoc name)))
288 uniq = nameUnique name
289 new_occ = mkLocalOcc uniq (nameOccName name)
290 -- We want to conjure up a name that can't clash with any
291 -- existing name. So we generate
293 -- where 243 is the unique.
296 | opt_EnsureSplittableC = CSplitMarker
297 | otherwise = AbsCNop