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 ( 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 ( ModGuts(..), ModGuts, ForeignStubs(..), TypeEnv,
45 import CostCentre ( CollectedCCs )
46 import Id ( Id, idName, setIdName )
47 import Name ( nameSrcLoc, nameOccName, nameUnique, isInternalName, mkExternalName )
48 import OccName ( mkLocalOcc )
49 import PrimRep ( PrimRep(..) )
50 import TyCon ( isDataTyCon )
51 import Module ( Module )
52 import BasicTypes ( TopLevelFlag(..) )
53 import UniqSupply ( mkSplitUniqSupply )
54 import ErrUtils ( dumpIfSet_dyn, showPass )
55 import Panic ( assertPanic )
61 import DATA_IOREF ( readIORef )
69 -> [Module] -- directly-imported modules
70 -> CollectedCCs -- (Local/global) cost-centres needing declaring/registering.
71 -> [(StgBinding,[Id])] -- Bindings to convert, with SRTs
72 -> IO AbstractC -- Output
74 codeGen dflags this_mod type_env foreign_stubs imported_mods
75 cost_centre_info stg_binds
77 showPass dflags "CodeGen"
78 fl_uniqs <- mkSplitUniqSupply 'f'
79 way <- readIORef v_Build_tag
82 tycons = typeEnvTyCons type_env
83 data_tycons = filter isDataTyCon tycons
85 mapM_ (\x -> seq x (return ())) data_tycons
89 cinfo = MkCompInfo this_mod
91 datatype_stuff = genStaticConBits cinfo data_tycons
92 code_stuff = initC cinfo (mapCs cgTopBinding stg_binds)
93 init_stuff = mkModuleInit way cost_centre_info this_mod
94 foreign_stubs imported_mods
96 abstractC = mkAbstractCs [ maybeSplitCode,
100 -- Put datatype_stuff after code_stuff, because the
101 -- datatype closure table (for enumeration types) to
102 -- (say) PrelBase_True_closure, which is defined in
105 dumpIfSet_dyn dflags Opt_D_dump_absC "Abstract C" (dumpRealC abstractC)
107 return $! flattenAbsC fl_uniqs abstractC
110 %************************************************************************
112 \subsection[codegen-init]{Module initialisation code}
114 %************************************************************************
118 :: String -- the "way"
119 -> CollectedCCs -- cost centre info
124 mkModuleInit way cost_centre_info this_mod foreign_stubs imported_mods
126 (cc_decls, cc_regs) = mkCostCentreStuff cost_centre_info
128 register_foreign_exports
129 = case foreign_stubs of
131 ForeignStubs _ _ _ fe_bndrs -> map mk_export_register fe_bndrs
133 mk_export_register bndr
134 = CMacroStmt REGISTER_FOREIGN_EXPORT [lbl]
136 lbl = CLbl (mkClosureLabel (idName bndr)) PtrRep
137 -- we don't want/need to init GHC.Prim, so filter it out
139 mk_import_register mod
140 | mod == gHC_PRIM = AbsCNop
141 | otherwise = CMacroStmt REGISTER_IMPORT [
142 CLbl (mkModuleInitLabel mod way) AddrRep
145 register_mod_imports = map mk_import_register imported_mods
149 CModuleInitBlock (mkPlainModuleInitLabel this_mod)
150 (mkModuleInitLabel this_mod way)
151 (mkAbstractCs (register_foreign_exports ++
153 register_mod_imports))
157 Cost-centre profiling: Besides the usual stuff, we must produce
158 declarations for the cost-centres defined in this module;
160 (The local cost-centres involved in this are passed into the
164 mkCostCentreStuff (local_CCs, extern_CCs, singleton_CCSs)
165 | not opt_SccProfilingOn = (AbsCNop, AbsCNop)
168 map (CCostCentreDecl True) local_CCs ++
169 map (CCostCentreDecl False) extern_CCs ++
170 map CCostCentreStackDecl singleton_CCSs),
171 mkAbstractCs (mkCcRegister local_CCs singleton_CCSs)
174 mkCcRegister ccs cc_stacks
176 register_ccs = mkAbstractCs (map mk_register ccs)
177 register_cc_stacks = mkAbstractCs (map mk_register_ccs cc_stacks)
179 [ register_ccs, register_cc_stacks ]
182 = CCallProfCCMacro FSLIT("REGISTER_CC") [mkCCostCentre cc]
185 = CCallProfCCMacro FSLIT("REGISTER_CCS") [mkCCostCentreStack ccs]
188 %************************************************************************
190 \subsection[codegen-top-bindings]{Converting top-level STG bindings}
192 %************************************************************************
194 @cgTopBinding@ is only used for top-level bindings, since they need
195 to be allocated statically (not in the heap) and need to be labelled.
196 No unboxed bindings can happen at top level.
198 In the code below, the static bindings are accumulated in the
199 @MkCgState@, and transferred into the ``statics'' slot by @forkStatics@.
200 This is so that we can write the top level processing in a compositional
201 style, with the increasing static environment being plumbed as a state
205 cgTopBinding :: (StgBinding,[Id]) -> Code
206 cgTopBinding (StgNonRec srt_info id rhs, srt)
207 = absC maybeSplitCode `thenC`
208 maybeExternaliseId id `thenFC` \ id' ->
210 srt_label = mkSRTLabel (idName id')
212 mkSRT srt_label srt [] `thenC`
213 setSRTLabel srt_label (
214 cgTopRhs id' rhs srt_info `thenFC` \ (id, info) ->
215 addBindC id info -- Add the un-externalised Id to the envt, so we
216 -- find it when we look up occurrences
219 cgTopBinding (StgRec srt_info pairs, srt)
220 = absC maybeSplitCode `thenC`
222 (bndrs, rhss) = unzip pairs
224 mapFCs maybeExternaliseId bndrs `thenFC` \ bndrs'@(id:_) ->
226 srt_label = mkSRTLabel (idName id)
227 pairs' = zip bndrs' rhss
229 mkSRT srt_label srt bndrs' `thenC`
230 setSRTLabel srt_label (
232 addBindsC new_binds `thenC`
233 mapFCs ( \ (b,e) -> cgTopRhs b e srt_info ) pairs'
234 ) `thenFC` \ new_binds -> nopC
237 mkSRT :: CLabel -> [Id] -> [Id] -> Code
238 mkSRT lbl [] these = nopC
240 = mapFCs remap ids `thenFC` \ ids ->
241 absC (CSRT lbl (map (mkClosureLabel . idName) ids))
243 -- sigh, better map all the ids against the environment in case they've
244 -- been externalised (see maybeExternaliseId below).
245 remap id = case filter (==id) these of
246 [] -> getCAddrModeAndInfo id
247 `thenFC` \ (id, _, _) -> returnFC id
248 (id':_) -> returnFC id'
250 -- Urgh! I tried moving the forkStatics call from the rhss of cgTopRhs
251 -- to enclose the listFCs in cgTopBinding, but that tickled the
252 -- statics "error" call in initC. I DON'T UNDERSTAND WHY!
254 cgTopRhs :: Id -> StgRhs -> SRT -> FCode (Id, CgIdInfo)
255 -- The Id is passed along for setting up a binding...
256 -- It's already been externalised if necessary
258 cgTopRhs bndr (StgRhsCon cc con args) srt
259 = forkStatics (cgTopRhsCon bndr con args srt)
261 cgTopRhs bndr (StgRhsClosure cc bi fvs upd_flag args body) srt
262 = ASSERT(null fvs) -- There should be no free variables
264 lf_info = mkClosureLFInfo bndr TopLevel [{-no fvs-}] upd_flag args
266 forkStatics (cgTopRhsClosure bndr cc bi srt args body lf_info)
270 %************************************************************************
272 \subsection{Stuff to support splitting}
274 %************************************************************************
276 If we're splitting the object, we need to externalise all the top-level names
277 (and then make sure we only use the externalised one in any C label we use
278 which refers to this name).
281 maybeExternaliseId :: Id -> FCode Id
282 maybeExternaliseId id
283 | opt_EnsureSplittableC, -- Externalise the name for -split-objs
285 = moduleName `thenFC` \ mod ->
286 returnFC (setIdName id (mkExternalName uniq mod new_occ (nameSrcLoc name)))
291 uniq = nameUnique name
292 new_occ = mkLocalOcc uniq (nameOccName name)
293 -- We want to conjure up a name that can't clash with any
294 -- existing name. So we generate
296 -- where 243 is the unique.
299 | opt_EnsureSplittableC = CSplitMarker
300 | otherwise = AbsCNop