File : sem_ch6.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S E M _ C H 6 --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2016, 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 Types; use Types;
27 package Sem_Ch6 is
28
29 type Conformance_Type is
30 (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
31 pragma Ordered (Conformance_Type);
32 -- Conformance type used in conformance checks between specs and bodies,
33 -- and for overriding. The literals match the RM definitions of the
34 -- corresponding terms. This is an ordered type, since each conformance
35 -- type is stronger than the ones preceding it.
36
37 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id);
38 procedure Analyze_Expression_Function (N : Node_Id);
39 procedure Analyze_Extended_Return_Statement (N : Node_Id);
40 procedure Analyze_Function_Call (N : Node_Id);
41 procedure Analyze_Operator_Symbol (N : Node_Id);
42 procedure Analyze_Parameter_Association (N : Node_Id);
43 procedure Analyze_Procedure_Call (N : Node_Id);
44 procedure Analyze_Simple_Return_Statement (N : Node_Id);
45 procedure Analyze_Subprogram_Declaration (N : Node_Id);
46 procedure Analyze_Subprogram_Body (N : Node_Id);
47
48 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id;
49 -- Analyze subprogram specification in both subprogram declarations
50 -- and body declarations. Returns the defining entity for the
51 -- specification N.
52
53 procedure Check_Conventions (Typ : Entity_Id);
54 -- Ada 2005 (AI-430): Check that the conventions of all inherited and
55 -- overridden dispatching operations of type Typ are consistent with their
56 -- respective counterparts.
57
58 procedure Check_Delayed_Subprogram (Designator : Entity_Id);
59 -- Designator can be a E_Subprogram_Type, E_Procedure or E_Function. If a
60 -- type in its profile depends on a private type without a full
61 -- declaration, indicate that the subprogram or type is delayed.
62
63 procedure Check_Discriminant_Conformance
64 (N : Node_Id;
65 Prev : Entity_Id;
66 Prev_Loc : Node_Id);
67 -- Check that the discriminants of a full type N fully conform to the
68 -- discriminants of the corresponding partial view Prev. Prev_Loc indicates
69 -- the source location of the partial view, which may be different than
70 -- Prev in the case of private types.
71
72 procedure Check_Fully_Conformant
73 (New_Id : Entity_Id;
74 Old_Id : Entity_Id;
75 Err_Loc : Node_Id := Empty);
76 -- Check that two callable entities (subprograms, entries, literals)
77 -- are fully conformant, post error message if not (RM 6.3.1(17)) with
78 -- the flag being placed on the Err_Loc node if it is specified, and
79 -- on the appropriate component of the New_Id construct if not. Note:
80 -- when checking spec/body conformance, New_Id must be the body entity
81 -- and Old_Id is the spec entity (the code in the implementation relies
82 -- on this ordering, and in any case, this makes sense, since if flags
83 -- are to be placed on the construct, they clearly belong on the body.
84
85 procedure Check_Mode_Conformant
86 (New_Id : Entity_Id;
87 Old_Id : Entity_Id;
88 Err_Loc : Node_Id := Empty;
89 Get_Inst : Boolean := False);
90 -- Check that two callable entities (subprograms, entries, literals)
91 -- are mode conformant, post error message if not (RM 6.3.1(15)) with
92 -- the flag being placed on the Err_Loc node if it is specified, and
93 -- on the appropriate component of the New_Id construct if not. The
94 -- argument Get_Inst is set to True when this is a check against a
95 -- formal access-to-subprogram type, indicating that mapping of types
96 -- is needed.
97
98 procedure Check_Overriding_Indicator
99 (Subp : Entity_Id;
100 Overridden_Subp : Entity_Id;
101 Is_Primitive : Boolean);
102 -- Verify the consistency of an overriding_indicator given for subprogram
103 -- declaration, body, renaming, or instantiation. Overridden_Subp is set
104 -- if the scope where we are introducing the subprogram contains a
105 -- type-conformant subprogram that becomes hidden by the new subprogram.
106 -- Is_Primitive indicates whether the subprogram is primitive.
107
108 procedure Check_Subtype_Conformant
109 (New_Id : Entity_Id;
110 Old_Id : Entity_Id;
111 Err_Loc : Node_Id := Empty;
112 Skip_Controlling_Formals : Boolean := False;
113 Get_Inst : Boolean := False);
114 -- Check that two callable entities (subprograms, entries, literals)
115 -- are subtype conformant, post error message if not (RM 6.3.1(16)),
116 -- the flag being placed on the Err_Loc node if it is specified, and
117 -- on the appropriate component of the New_Id construct if not.
118 -- Skip_Controlling_Formals is True when checking the conformance of
119 -- a subprogram that implements an interface operation. In that case,
120 -- only the non-controlling formals can (and must) be examined. The
121 -- argument Get_Inst is set to True when this is a check against a
122 -- formal access-to-subprogram type, indicating that mapping of types
123 -- is needed.
124
125 procedure Check_Synchronized_Overriding
126 (Def_Id : Entity_Id;
127 Overridden_Subp : out Entity_Id);
128 -- First determine if Def_Id is an entry or a subprogram either defined in
129 -- the scope of a task or protected type, or that is a primitive of such
130 -- a type. Check whether Def_Id overrides a subprogram of an interface
131 -- implemented by the synchronized type, returning the overridden entity
132 -- or Empty.
133
134 procedure Check_Type_Conformant
135 (New_Id : Entity_Id;
136 Old_Id : Entity_Id;
137 Err_Loc : Node_Id := Empty);
138 -- Check that two callable entities (subprograms, entries, literals)
139 -- are type conformant, post error message if not (RM 6.3.1(14)) with
140 -- the flag being placed on the Err_Loc node if it is specified, and
141 -- on the appropriate component of the New_Id construct if not.
142
143 function Conforming_Types
144 (T1 : Entity_Id;
145 T2 : Entity_Id;
146 Ctype : Conformance_Type;
147 Get_Inst : Boolean := False) return Boolean;
148 -- Check that the types of two formal parameters are conforming. In most
149 -- cases this is just a name comparison, but within an instance it involves
150 -- generic actual types, and in the presence of anonymous access types
151 -- it must examine the designated types. The argument Get_Inst is set to
152 -- True when this is a check against a formal access-to-subprogram type,
153 -- indicating that mapping of types is needed.
154
155 procedure Create_Extra_Formals (E : Entity_Id);
156 -- For each parameter of a subprogram or entry that requires an additional
157 -- formal (such as for access parameters and indefinite discriminated
158 -- parameters), creates the appropriate formal and attach it to its
159 -- associated parameter. Each extra formal will also be appended to
160 -- the end of Subp's parameter list (with each subsequent extra formal
161 -- being attached to the preceding extra formal).
162
163 function Find_Corresponding_Spec
164 (N : Node_Id;
165 Post_Error : Boolean := True) return Entity_Id;
166 -- Use the subprogram specification in the body to retrieve the previous
167 -- subprogram declaration, if any.
168
169 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
170 -- Determine whether two callable entities (subprograms, entries,
171 -- literals) are fully conformant (RM 6.3.1(17))
172
173 function Fully_Conformant_Expressions
174 (Given_E1 : Node_Id;
175 Given_E2 : Node_Id) return Boolean;
176 -- Determines if two (non-empty) expressions are fully conformant
177 -- as defined by (RM 6.3.1(18-21))
178
179 function Fully_Conformant_Discrete_Subtypes
180 (Given_S1 : Node_Id;
181 Given_S2 : Node_Id) return Boolean;
182 -- Determines if two subtype definitions are fully conformant. Used
183 -- for entry family conformance checks (RM 6.3.1 (24)).
184
185 procedure Install_Entity (E : Entity_Id);
186 -- Place a single entity on the visibility chain
187
188 procedure Install_Formals (Id : Entity_Id);
189 -- On entry to a subprogram body, make the formals visible. Note that
190 -- simply placing the subprogram on the scope stack is not sufficient:
191 -- the formals must become the current entities for their names. This
192 -- procedure is also used to get visibility to the formals when analyzing
193 -- preconditions and postconditions appearing in the spec.
194
195 function Is_Interface_Conformant
196 (Tagged_Type : Entity_Id;
197 Iface_Prim : Entity_Id;
198 Prim : Entity_Id) return Boolean;
199 -- Returns true if both primitives have a matching name (including support
200 -- for names of inherited private primitives --which have suffix 'P'), they
201 -- are type conformant, and Prim is defined in the scope of Tagged_Type.
202 -- Special management is done for functions returning interfaces.
203
204 procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id);
205 -- E is the entity for a subprogram or generic subprogram spec. This call
206 -- lists all inherited Pre/Post aspects if List_Inherited_Pre_Post is True.
207
208 procedure May_Need_Actuals (Fun : Entity_Id);
209 -- Flag functions that can be called without parameters, i.e. those that
210 -- have no parameters, or those for which defaults exist for all parameters
211 -- Used for subprogram declarations and for access subprogram declarations,
212 -- where they apply to the anonymous designated type. On return the flag
213 -- Set_Needs_No_Actuals is set appropriately in Fun.
214
215 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
216 -- Determine whether two callable entities (subprograms, entries,
217 -- literals) are mode conformant (RM 6.3.1(15))
218
219 procedure New_Overloaded_Entity
220 (S : Entity_Id;
221 Derived_Type : Entity_Id := Empty);
222 -- Process new overloaded entity. Overloaded entities are created by
223 -- enumeration type declarations, subprogram specifications, entry
224 -- declarations, and (implicitly) by type derivations. If Derived_Type
225 -- is non-empty then this is a subprogram derived for that type.
226
227 procedure Process_Formals (T : List_Id; Related_Nod : Node_Id);
228 -- Enter the formals in the scope of the subprogram or entry, and
229 -- analyze default expressions if any. The implicit types created for
230 -- access parameter are attached to the Related_Nod which comes from the
231 -- context.
232
233 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
234 -- If there is a separate spec for a subprogram or generic subprogram, the
235 -- formals of the body are treated as references to the corresponding
236 -- formals of the spec. This reference does not count as an actual use of
237 -- the formal, in order to diagnose formals that are unused in the body.
238 -- This procedure is also used in renaming_as_body declarations, where
239 -- the formals of the specification must be treated as body formals that
240 -- correspond to the previous subprogram declaration, and not as new
241 -- entities with their defining entry in the cross-reference information.
242
243 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id);
244 -- If the formals of a subprogram are unconstrained, build a subtype
245 -- declaration that uses the bounds or discriminants of the actual to
246 -- construct an actual subtype for them. This is an optimization that
247 -- is done only in some cases where the actual subtype cannot change
248 -- during execution of the subprogram. By setting the actual subtype
249 -- once, we avoid recomputing it unnecessarily.
250
251 procedure Set_Formal_Mode (Formal_Id : Entity_Id);
252 -- Set proper Ekind to reflect formal mode (in, out, in out)
253
254 function Subtype_Conformant
255 (New_Id : Entity_Id;
256 Old_Id : Entity_Id;
257 Skip_Controlling_Formals : Boolean := False) return Boolean;
258 -- Determine whether two callable entities (subprograms, entries, literals)
259 -- are subtype conformant (RM 6.3.1(16)). Skip_Controlling_Formals is True
260 -- when checking the conformance of a subprogram that implements an
261 -- interface operation. In that case, only the non-controlling formals
262 -- can (and must) be examined.
263
264 function Type_Conformant
265 (New_Id : Entity_Id;
266 Old_Id : Entity_Id;
267 Skip_Controlling_Formals : Boolean := False) return Boolean;
268 -- Determine whether two callable entities (subprograms, entries, literals)
269 -- are type conformant (RM 6.3.1(14)). Skip_Controlling_Formals is True
270 -- when checking the conformance of a subprogram that implements an
271 -- interface operation. In that case, only the non-controlling formals
272 -- can (and must) be examined.
273
274 procedure Valid_Operator_Definition (Designator : Entity_Id);
275 -- Verify that an operator definition has the proper number of formals
276
277 end Sem_Ch6;