2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[CgConTbls]{Info tables and update bits for constructors}
7 module CgConTbls ( genStaticConBits ) where
9 #include "HsVersions.h"
14 import AbsCUtils ( mkAbstractCs, mkAbsCStmts )
15 import CgTailCall ( performReturn, mkStaticAlgReturnCode )
16 import CLabel ( mkConEntryLabel )
17 import ClosureInfo ( layOutStaticClosure, layOutDynCon,
18 mkConLFInfo, ClosureInfo
20 import CostCentre ( dontCareCCS )
21 import DataCon ( DataCon, dataConName, dataConRepArgTys, isNullaryDataCon )
22 import Name ( getOccName )
23 import OccName ( occNameUserString )
24 import PrimRep ( getPrimRepSize, PrimRep(..) )
25 import TyCon ( tyConDataCons, isEnumerationTyCon, TyCon )
26 import Type ( typePrimRep )
29 For every constructor we generate the following info tables:
30 A static info table, for static instances of the constructor,
35 Info tbls & Macro & Kind of constructor \\
37 info & @CONST_INFO_TABLE@& Zero arity (no info -- compiler uses static closure)\\
38 info & @CHARLIKE_INFO_TABLE@& Charlike (no info -- compiler indexes fixed array)\\
39 info & @INTLIKE_INFO_TABLE@& Intlike; the one macro generates both info tbls\\
40 info & @SPEC_INFO_TABLE@& SPECish, and bigger than or equal to @MIN_UPD_SIZE@\\
41 info & @GEN_INFO_TABLE@& GENish (hence bigger than or equal to @MIN_UPD_SIZE@)\\
44 Possible info tables for constructor con:
48 Used for dynamically let(rec)-bound occurrences of
49 the constructor, and for updates. For constructors
50 which are int-like, char-like or nullary, when GC occurs,
51 the closure tries to get rid of itself.
53 \item[@_static_info@:]
54 Static occurrences of the constructor
55 macro: @STATIC_INFO_TABLE@.
59 For zero-arity constructors, \tr{con}, we NO LONGER generate a static closure;
60 it's place is taken by the top level defn of the constructor.
62 For charlike and intlike closures there is a fixed array of static
66 genStaticConBits :: CompilationInfo -- global info about the compilation
67 -> [TyCon] -- tycons to generate
68 -> AbstractC -- output
70 genStaticConBits comp_info gen_tycons
71 = -- for each type constructor:
72 -- grab all its data constructors;
73 -- for each one, generate an info table
74 -- for each specialised type constructor
75 -- for each specialisation of the type constructor
76 -- grab data constructors, and generate info tables
78 -- ToDo: for tycons and specialisations which are not
79 -- declared in this module we must ensure that the
80 -- C labels are local to this module i.e. static
81 -- since they may be duplicated in other modules
83 mkAbstractCs [ gen_for_tycon tc | tc <- gen_tycons ]
85 gen_for_tycon :: TyCon -> AbstractC
87 = mkAbstractCs (map (genConInfo comp_info tycon) (tyConDataCons tycon))
89 -- after the con decls, so we don't need to declare the constructor labels
90 if (isEnumerationTyCon tycon)
91 then CClosureTbl tycon
96 %************************************************************************
98 \subsection[CgConTbls-info-tables]{Generating info tables for constructors}
100 %************************************************************************
102 Generate the entry code, info tables, and (for niladic constructor) the
103 static closure, for a constructor.
106 genConInfo :: CompilationInfo -> TyCon -> DataCon -> AbstractC
108 genConInfo comp_info tycon data_con
113 -- Order of things is to reduce forward references
115 (closure_info, body_code) = mkConCodeAndInfo data_con
117 -- To allow the debuggers, interpreters, etc to cope with static
118 -- data structures (ie those built at compile time), we take care that
119 -- info-table contains the information we need.
120 (static_ci,_) = layOutStaticClosure con_name typePrimRep arg_tys
121 (mkConLFInfo data_con)
123 body = (initC comp_info (
124 profCtrC SLIT("TICK_ENT_CON") [CReg node] `thenC`
127 entry_addr = CLbl entry_label CodePtrRep
128 con_descr = occNameUserString (getOccName data_con)
130 -- Don't need any dynamic closure code for zero-arity constructors
131 closure_code = if zero_arity_con then
134 CClosureInfoAndCode closure_info body Nothing con_descr
136 static_code = CClosureInfoAndCode static_ci body Nothing con_descr
138 cost_centre = mkCCostCentreStack dontCareCCS -- not worried about static data costs
140 zero_size arg_ty = getPrimRepSize (typePrimRep arg_ty) == 0
142 zero_arity_con = isNullaryDataCon data_con
143 -- We used to check that all the arg-sizes were zero, but we don't
144 -- really have any constructors with only zero-size args, and it's
145 -- just one more thing to go wrong.
147 arg_tys = dataConRepArgTys data_con
148 entry_label = mkConEntryLabel con_name
149 con_name = dataConName data_con
153 mkConCodeAndInfo :: DataCon -- Data constructor
154 -> (ClosureInfo, Code) -- The info table
158 arg_tys = dataConRepArgTys con
160 (closure_info, arg_things)
161 = layOutDynCon con typePrimRep arg_tys
164 = -- NB: We don't set CC when entering data (WDP 94/06)
165 profCtrC SLIT("TICK_RET_OLD")
166 [mkIntCLit (length arg_things)] `thenC`
168 performReturn AbsCNop -- Ptr to thing already in Node
169 (mkStaticAlgReturnCode con)
171 (closure_info, body_code)