Copyright (C) 1992, Digital Equipment Corporation
All rights reserved.
See the file COPYRIGHT for a full description.
<* PRAGMA FIELDS *>
INTERFACE M3AST_SC;
This interface defines some additional attributes that make
an AST self contained. Such an AST is capable of being pickled
as a single entity, that is, with all references to entities
on other ASTs represented (in the pickle) via surrogate nodes
that provide for safe recombination when the AST is unpickled.
IMPORT M3AST, M3AST_AS;
TYPE
Surrogate nodes that replace inter-AST references multiply inherit
the IMPORTED_NODE class, which carries the information on how
to locate the actual nodes. A Unit_stub, shared between all
reference to the same unit, locates the unit by name, type
and unique identifier (allowing version checks). The sc_eoi
field of an IMPORTED_NODE is the index in the sc_exported_node_s
of the Compilation_Unit node of the AST that the sc_unit_stub field
locates.
IMPORTED_NODE <: M3AST.NODE;
<* FIELDS OF IMPORTED_NODE
sc_unit_stub: Unit_stub;
sc_eoi: INTEGER *>
Unit_stub <: M3AST.NODE;
<* FIELDS OF Unit_stub
sc_unit_symrep: M3AST_LX.Symbol_rep;
sc_unit_type: M3AST_FE.Unit_type;
sc_unit_uid: M3AST_FE.Unit_uid;
*>
The only inter-AST references thus far are to DEF_ID and
TYPE_SPEC nodes.
Imported_id <: M3AST_AS.DEF_ID;
<* FIELDS OF Imported_id
sc_actual_id: M3AST_AS.DEF_ID;
vIMPORTED_NODE: IMPORTED_NODE; *>
Imported_type <: M3AST_AS.TYPE_SPEC;
<* FIELDS OF Imported_type
sc_actual_type: M3AST_AS.TYPE_SPEC;
vIMPORTED_NODE: IMPORTED_NODE; *>
Exported_node <: M3AST.NODE;
<* FIELDS OF Exported_node
sc_actual_node: M3AST_AS.SRC_NODE; (* TYPE_SPEC or DEF_ID *) *>
<* FIELDS OF M3AST_AS.Compilation_Unit
sc_unit_stub_s: SEQUENCE OF Unit_stub;
sc_exported_node_s: SEQUENCE OF Exported_node; *>
The sc_exported_node_s tabulates the nodes defined in the AST
rooted at this node. The sc_unit_stub_s denotes the units
to which this AST has inter-AST references.
END M3AST_SC.