File : sem_scil.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ S C I L --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2009-2012, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
25
26 with Einfo; use Einfo;
27 with Nlists; use Nlists;
28 with Rtsfind; use Rtsfind;
29 with Sem_Aux; use Sem_Aux;
30 with Sinfo; use Sinfo;
31 with Stand; use Stand;
32 with SCIL_LL; use SCIL_LL;
33
34 package body Sem_SCIL is
35
36 ---------------------
37 -- Check_SCIL_Node --
38 ---------------------
39
40 function Check_SCIL_Node (N : Node_Id) return Traverse_Result is
41 SCIL_Node : constant Node_Id := Get_SCIL_Node (N);
42 Ctrl_Tag : Node_Id;
43 Ctrl_Typ : Entity_Id;
44
45 begin
46 -- For nodes that do not have SCIL node continue traversing the tree
47
48 if No (SCIL_Node) then
49 return OK;
50 end if;
51
52 case Nkind (SCIL_Node) is
53 when N_SCIL_Dispatch_Table_Tag_Init =>
54 pragma Assert (Nkind (N) = N_Object_Declaration);
55 null;
56
57 when N_SCIL_Dispatching_Call =>
58 Ctrl_Tag := SCIL_Controlling_Tag (SCIL_Node);
59
60 -- Parent of SCIL dispatching call nodes MUST be a subprogram call
61
62 if Nkind (N) not in N_Subprogram_Call then
63 raise Program_Error;
64
65 -- In simple cases the controlling tag is the tag of the
66 -- controlling argument (i.e. Obj.Tag).
67
68 elsif Nkind (Ctrl_Tag) = N_Selected_Component then
69 Ctrl_Typ := Etype (Ctrl_Tag);
70
71 -- Interface types are unsupported
72
73 if Is_Interface (Ctrl_Typ)
74 or else (RTE_Available (RE_Interface_Tag)
75 and then Ctrl_Typ = RTE (RE_Interface_Tag))
76 then
77 null;
78
79 else
80 pragma Assert (Ctrl_Typ = RTE (RE_Tag));
81 null;
82 end if;
83
84 -- When the controlling tag of a dispatching call is an identifier
85 -- the SCIL_Controlling_Tag attribute references the corresponding
86 -- object or parameter declaration. Interface types are still
87 -- unsupported.
88
89 elsif Nkind_In (Ctrl_Tag, N_Object_Declaration,
90 N_Parameter_Specification)
91 then
92 Ctrl_Typ := Etype (Defining_Identifier (Ctrl_Tag));
93
94 -- Interface types are unsupported.
95
96 if Is_Interface (Ctrl_Typ)
97 or else (RTE_Available (RE_Interface_Tag)
98 and then Ctrl_Typ = RTE (RE_Interface_Tag))
99 or else (Is_Access_Type (Ctrl_Typ)
100 and then
101 Is_Interface
102 (Available_View
103 (Base_Type (Designated_Type (Ctrl_Typ)))))
104 then
105 null;
106
107 else
108 pragma Assert
109 (Ctrl_Typ = RTE (RE_Tag)
110 or else
111 (Is_Access_Type (Ctrl_Typ)
112 and then Available_View
113 (Base_Type (Designated_Type (Ctrl_Typ)))
114 = RTE (RE_Tag)));
115 null;
116 end if;
117
118 -- Interface types are unsupported
119
120 elsif Is_Interface (Etype (Ctrl_Tag)) then
121 null;
122
123 else
124 pragma Assert (False);
125 raise Program_Error;
126 end if;
127
128 return Skip;
129
130 when N_SCIL_Membership_Test =>
131
132 -- Check contents of the boolean expression associated with the
133 -- membership test.
134
135 pragma Assert (Nkind_In (N, N_Identifier,
136 N_And_Then,
137 N_Or_Else,
138 N_Expression_With_Actions)
139 and then Etype (N) = Standard_Boolean);
140
141 -- Check the entity identifier of the associated tagged type (that
142 -- is, in testing for membership in T'Class, the entity id of the
143 -- specific type T).
144
145 -- Note: When the SCIL node is generated the private and full-view
146 -- of the tagged types may have been swapped and hence the node
147 -- referenced by attribute SCIL_Entity may be the private view.
148 -- Therefore, in order to uniformly locate the full-view we use
149 -- attribute Underlying_Type.
150
151 pragma Assert
152 (Is_Tagged_Type (Underlying_Type (SCIL_Entity (SCIL_Node))));
153
154 -- Interface types are unsupported
155
156 pragma Assert
157 (not Is_Interface (Underlying_Type (SCIL_Entity (SCIL_Node))));
158
159 -- Check the decoration of the expression that denotes the tag
160 -- value being tested
161
162 Ctrl_Tag := SCIL_Tag_Value (SCIL_Node);
163
164 case Nkind (Ctrl_Tag) is
165
166 -- For class-wide membership tests the SCIL tag value is the
167 -- tag of the tested object (i.e. Obj.Tag).
168
169 when N_Selected_Component =>
170 pragma Assert (Etype (Ctrl_Tag) = RTE (RE_Tag));
171 null;
172
173 when others =>
174 pragma Assert (False);
175 null;
176 end case;
177
178 return Skip;
179
180 when others =>
181 pragma Assert (False);
182 raise Program_Error;
183 end case;
184
185 return Skip;
186 end Check_SCIL_Node;
187
188 -------------------------
189 -- First_Non_SCIL_Node --
190 -------------------------
191
192 function First_Non_SCIL_Node (L : List_Id) return Node_Id is
193 N : Node_Id;
194
195 begin
196 N := First (L);
197 while Nkind (N) in N_SCIL_Node loop
198 Next (N);
199 end loop;
200
201 return N;
202 end First_Non_SCIL_Node;
203
204 ------------------------
205 -- Next_Non_SCIL_Node --
206 ------------------------
207
208 function Next_Non_SCIL_Node (N : Node_Id) return Node_Id is
209 Aux_N : Node_Id;
210
211 begin
212 Aux_N := Next (N);
213 while Nkind (Aux_N) in N_SCIL_Node loop
214 Next (Aux_N);
215 end loop;
216
217 return Aux_N;
218 end Next_Non_SCIL_Node;
219
220 end Sem_SCIL;