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
30 import CLabel ( CLabel, mkSRTLabel, mkClosureLabel, mkModuleInitLabel )
32 import PprAbsC ( dumpRealC )
33 import AbsCUtils ( mkAbstractCs, flattenAbsC )
34 import CgBindery ( CgIdInfo, addBindC, addBindsC, getCAddrModeAndInfo )
35 import CgClosure ( cgTopRhsClosure )
36 import CgCon ( cgTopRhsCon )
37 import CgConTbls ( genStaticConBits )
38 import ClosureInfo ( mkClosureLFInfo )
39 import CmdLineOpts ( DynFlags, DynFlag(..),
40 opt_SccProfilingOn, opt_EnsureSplittableC )
41 import CostCentre ( CostCentre, CostCentreStack )
42 import Id ( Id, idName, setIdName )
43 import Name ( nameSrcLoc, nameOccName, nameUnique, isLocalName, mkGlobalName )
44 import OccName ( mkLocalOcc )
45 import Module ( Module )
46 import PrimRep ( PrimRep(..) )
47 import TyCon ( TyCon, isDataTyCon )
48 import BasicTypes ( TopLevelFlag(..) )
49 import UniqSupply ( mkSplitUniqSupply )
50 import ErrUtils ( dumpIfSet_dyn, showPass )
51 import Panic ( assertPanic )
60 -> Module -- Module name
61 -> [Module] -- Import names
62 -> ([CostCentre], -- Local cost-centres needing declaring/registering
63 [CostCentre], -- "extern" cost-centres needing declaring
64 [CostCentreStack]) -- Pre-defined "singleton" cost centre stacks
65 -> [Id] -- foreign-exported binders
66 -> [TyCon] -- Local tycons, including ones from classes
67 -> [(StgBinding,[Id])] -- Bindings to convert, with SRTs
68 -> IO AbstractC -- Output
70 codeGen dflags mod_name imported_modules cost_centre_info fe_binders
72 = do { showPass dflags "CodeGen"
74 ; fl_uniqs <- mkSplitUniqSupply 'f'
76 datatype_stuff = genStaticConBits cinfo data_tycons
77 code_stuff = initC cinfo (mapCs cgTopBinding stg_binds)
78 init_stuff = mkModuleInit fe_binders mod_name imported_modules
81 abstractC = mkAbstractCs [ maybeSplitCode,
85 -- Put datatype_stuff after code_stuff, because the
86 -- datatype closure table (for enumeration types)
87 -- to (say) PrelBase_True_closure, which is defined in code_stuff
89 flat_abstractC = flattenAbsC fl_uniqs abstractC
91 ; dumpIfSet_dyn dflags Opt_D_dump_absC "Abstract C" (dumpRealC abstractC)
92 ; return flat_abstractC
95 data_tycons = filter isDataTyCon tycons
96 cinfo = MkCompInfo mod_name
99 %************************************************************************
101 \subsection[codegen-init]{Module initialisation code}
103 %************************************************************************
107 :: [Id] -- foreign exported functions
108 -> Module -- module name
109 -> [Module] -- import names
110 -> ([CostCentre], -- cost centre info
114 mkModuleInit fe_binders mod imps cost_centre_info
117 map (\f -> CMacroStmt REGISTER_FOREIGN_EXPORT [f]) fe_labels
120 map (\f -> CLbl (mkClosureLabel (idName f)) PtrRep) fe_binders
122 (cc_decls, cc_regs) = mkCostCentreStuff cost_centre_info
124 mk_import_register imp =
125 CMacroStmt REGISTER_IMPORT [
126 CLbl (mkModuleInitLabel imp) AddrRep
129 register_imports = map mk_import_register imps
133 CModuleInitBlock (mkModuleInitLabel mod)
134 (mkAbstractCs (register_fes ++
140 Cost-centre profiling: Besides the usual stuff, we must produce
141 declarations for the cost-centres defined in this module;
143 (The local cost-centres involved in this are passed into the
147 mkCostCentreStuff (local_CCs, extern_CCs, singleton_CCSs)
148 | not opt_SccProfilingOn = (AbsCNop, AbsCNop)
151 map (CCostCentreDecl True) local_CCs ++
152 map (CCostCentreDecl False) extern_CCs ++
153 map CCostCentreStackDecl singleton_CCSs),
154 mkAbstractCs (mkCcRegister local_CCs singleton_CCSs)
157 mkCcRegister ccs cc_stacks
159 register_ccs = mkAbstractCs (map mk_register ccs)
160 register_cc_stacks = mkAbstractCs (map mk_register_ccs cc_stacks)
162 [ register_ccs, register_cc_stacks ]
165 = CCallProfCCMacro SLIT("REGISTER_CC") [mkCCostCentre cc]
168 = CCallProfCCMacro SLIT("REGISTER_CCS") [mkCCostCentreStack ccs]
171 %************************************************************************
173 \subsection[codegen-top-bindings]{Converting top-level STG bindings}
175 %************************************************************************
177 @cgTopBinding@ is only used for top-level bindings, since they need
178 to be allocated statically (not in the heap) and need to be labelled.
179 No unboxed bindings can happen at top level.
181 In the code below, the static bindings are accumulated in the
182 @MkCgState@, and transferred into the ``statics'' slot by @forkStatics@.
183 This is so that we can write the top level processing in a compositional
184 style, with the increasing static environment being plumbed as a state
188 cgTopBinding :: (StgBinding,[Id]) -> Code
189 cgTopBinding (StgNonRec srt_info id rhs, srt)
190 = absC maybeSplitCode `thenC`
191 maybeGlobaliseId id `thenFC` \ id' ->
193 srt_label = mkSRTLabel (idName id')
195 mkSRT srt_label srt [] `thenC`
196 setSRTLabel srt_label (
197 cgTopRhs id' rhs srt_info `thenFC` \ (id, info) ->
198 addBindC id info -- Add the un-globalised Id to the envt, so we
199 -- find it when we look up occurrences
202 cgTopBinding (StgRec srt_info pairs, srt)
203 = absC maybeSplitCode `thenC`
205 (bndrs, rhss) = unzip pairs
207 mapFCs maybeGlobaliseId bndrs `thenFC` \ bndrs'@(id:_) ->
209 srt_label = mkSRTLabel (idName id)
210 pairs' = zip bndrs' rhss
212 mkSRT srt_label srt bndrs' `thenC`
213 setSRTLabel srt_label (
215 addBindsC new_binds `thenC`
216 mapFCs ( \ (b,e) -> cgTopRhs b e srt_info ) pairs'
217 ) `thenFC` \ new_binds -> nopC
220 mkSRT :: CLabel -> [Id] -> [Id] -> Code
221 mkSRT lbl [] these = nopC
223 = mapFCs remap ids `thenFC` \ ids ->
224 absC (CSRT lbl (map (mkClosureLabel . idName) ids))
226 -- sigh, better map all the ids against the environment in case they've
227 -- been globalised (see maybeGlobaliseId below).
228 remap id = case filter (==id) these of
229 [] -> getCAddrModeAndInfo id
230 `thenFC` \ (id, _, _) -> returnFC id
231 (id':_) -> returnFC id'
233 -- Urgh! I tried moving the forkStatics call from the rhss of cgTopRhs
234 -- to enclose the listFCs in cgTopBinding, but that tickled the
235 -- statics "error" call in initC. I DON'T UNDERSTAND WHY!
237 cgTopRhs :: Id -> StgRhs -> SRT -> FCode (Id, CgIdInfo)
238 -- The Id is passed along for setting up a binding...
239 -- It's already been globalised if necessary
241 cgTopRhs bndr (StgRhsCon cc con args) srt
242 = forkStatics (cgTopRhsCon bndr con args)
244 cgTopRhs bndr (StgRhsClosure cc bi fvs upd_flag args body) srt
245 = -- There should be no free variables
248 lf_info = mkClosureLFInfo bndr TopLevel [{-no fvs-}] upd_flag args
250 forkStatics (cgTopRhsClosure bndr cc bi srt args body lf_info)
254 %************************************************************************
256 \subsection{Stuff to support splitting}
258 %************************************************************************
260 If we're splitting the object, we need to globalise all the top-level names
261 (and then make sure we only use the globalised one in any C label we use
262 which refers to this name).
265 maybeGlobaliseId :: Id -> FCode Id
267 | opt_EnsureSplittableC, -- Globalise the name for -split-objs
269 = moduleName `thenFC` \ mod ->
270 returnFC (setIdName id (mkGlobalName uniq mod new_occ (nameSrcLoc name)))
275 uniq = nameUnique name
276 new_occ = mkLocalOcc uniq (nameOccName name)
277 -- We want to conjure up a name that can't clash with any
278 -- existing name. So we generate
280 -- where 243 is the unique.
283 | opt_EnsureSplittableC = CSplitMarker
284 | otherwise = AbsCNop