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 ClosureInfo ( layOutStaticConstr, layOutDynConstr, ClosureInfo )
17 import DataCon ( DataCon, dataConName, dataConRepArgTys, isNullaryDataCon )
18 import Name ( getOccName )
19 import OccName ( occNameUserString )
20 import TyCon ( tyConDataCons, isEnumerationTyCon, TyCon )
21 import Type ( typePrimRep )
24 For every constructor we generate the following info tables:
25 A static info table, for static instances of the constructor,
30 Info tbls & Macro & Kind of constructor \\
32 info & @CONST_INFO_TABLE@& Zero arity (no info -- compiler uses static closure)\\
33 info & @CHARLIKE_INFO_TABLE@& Charlike (no info -- compiler indexes fixed array)\\
34 info & @INTLIKE_INFO_TABLE@& Intlike; the one macro generates both info tbls\\
35 info & @SPEC_INFO_TABLE@& SPECish, and bigger than or equal to @MIN_UPD_SIZE@\\
36 info & @GEN_INFO_TABLE@& GENish (hence bigger than or equal to @MIN_UPD_SIZE@)\\
39 Possible info tables for constructor con:
43 Used for dynamically let(rec)-bound occurrences of
44 the constructor, and for updates. For constructors
45 which are int-like, char-like or nullary, when GC occurs,
46 the closure tries to get rid of itself.
48 \item[@_static_info@:]
49 Static occurrences of the constructor
50 macro: @STATIC_INFO_TABLE@.
54 For zero-arity constructors, \tr{con}, we NO LONGER generate a static closure;
55 it's place is taken by the top level defn of the constructor.
57 For charlike and intlike closures there is a fixed array of static
61 genStaticConBits :: CompilationInfo -- global info about the compilation
62 -> [TyCon] -- tycons to generate
63 -> AbstractC -- output
65 genStaticConBits comp_info gen_tycons
66 = -- for each type constructor:
67 -- grab all its data constructors;
68 -- for each one, generate an info table
69 -- for each specialised type constructor
70 -- for each specialisation of the type constructor
71 -- grab data constructors, and generate info tables
73 -- ToDo: for tycons and specialisations which are not
74 -- declared in this module we must ensure that the
75 -- C labels are local to this module i.e. static
76 -- since they may be duplicated in other modules
78 mkAbstractCs [ gen_for_tycon tc | tc <- gen_tycons ]
80 gen_for_tycon :: TyCon -> AbstractC
82 = mkAbstractCs (map (genConInfo comp_info tycon) (tyConDataCons tycon))
84 -- after the con decls, so we don't need to declare the constructor labels
85 if (isEnumerationTyCon tycon)
86 then CClosureTbl tycon
91 %************************************************************************
93 \subsection[CgConTbls-info-tables]{Generating info tables for constructors}
95 %************************************************************************
97 Generate the entry code, info tables, and (for niladic constructor) the
98 static closure, for a constructor.
101 genConInfo :: CompilationInfo -> TyCon -> DataCon -> AbstractC
103 genConInfo comp_info tycon data_con
108 -- Order of things is to reduce forward references
110 (closure_info, body_code) = mkConCodeAndInfo data_con
112 -- To allow the debuggers, interpreters, etc to cope with static
113 -- data structures (ie those built at compile time), we take care that
114 -- info-table contains the information we need.
115 (static_ci,_) = layOutStaticConstr con_name data_con typePrimRep arg_tys
117 body = (initC comp_info (
118 profCtrC SLIT("TICK_ENT_CON") [CReg node] `thenC`
121 con_descr = occNameUserString (getOccName data_con)
123 -- Don't need any dynamic closure code for zero-arity constructors
124 closure_code = if zero_arity_con then
127 CClosureInfoAndCode closure_info body Nothing con_descr
129 static_code = CClosureInfoAndCode static_ci body Nothing con_descr
131 zero_arity_con = isNullaryDataCon data_con
132 -- We used to check that all the arg-sizes were zero, but we don't
133 -- really have any constructors with only zero-size args, and it's
134 -- just one more thing to go wrong.
136 arg_tys = dataConRepArgTys data_con
137 con_name = dataConName data_con
141 mkConCodeAndInfo :: DataCon -- Data constructor
142 -> (ClosureInfo, Code) -- The info table
146 arg_tys = dataConRepArgTys con
148 (closure_info, arg_things)
149 = layOutDynConstr (dataConName con) con typePrimRep arg_tys
152 = -- NB: We don't set CC when entering data (WDP 94/06)
153 profCtrC SLIT("TICK_RET_OLD")
154 [mkIntCLit (length arg_things)] `thenC`
156 performReturn AbsCNop -- Ptr to thing already in Node
157 (mkStaticAlgReturnCode con)
159 (closure_info, body_code)