File : exp_ch6.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ 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 -- Expand routines for chapter 6 constructs
27
28 with Types; use Types;
29
30 package Exp_Ch6 is
31
32 procedure Expand_N_Extended_Return_Statement (N : Node_Id);
33 procedure Expand_N_Function_Call (N : Node_Id);
34 procedure Expand_N_Procedure_Call_Statement (N : Node_Id);
35 procedure Expand_N_Simple_Return_Statement (N : Node_Id);
36 procedure Expand_N_Subprogram_Body (N : Node_Id);
37 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id);
38 procedure Expand_N_Subprogram_Declaration (N : Node_Id);
39
40 procedure Expand_Call (N : Node_Id);
41 -- This procedure contains common processing for Expand_N_Function_Call,
42 -- Expand_N_Procedure_Statement, and Expand_N_Entry_Call.
43
44 procedure Freeze_Subprogram (N : Node_Id);
45 -- generate the appropriate expansions related to Subprogram freeze
46 -- nodes (e.g. the filling of the corresponding Dispatch Table for
47 -- Primitive Operations)
48
49 -- The following type defines the various forms of allocation used for the
50 -- results of build-in-place function calls.
51
52 type BIP_Allocation_Form is
53 (Unspecified,
54 Caller_Allocation,
55 Secondary_Stack,
56 Global_Heap,
57 User_Storage_Pool);
58
59 type BIP_Formal_Kind is
60 -- Ada 2005 (AI-318-02): This type defines the kinds of implicit extra
61 -- formals created for build-in-place functions. The order of these
62 -- enumeration literals matches the order in which the formals are
63 -- declared. See Sem_Ch6.Create_Extra_Formals.
64
65 (BIP_Alloc_Form,
66 -- Present if result subtype is unconstrained or tagged. Indicates
67 -- whether the return object is allocated by the caller or callee, and
68 -- if the callee, whether to use the secondary stack or the heap. See
69 -- Create_Extra_Formals.
70
71 BIP_Storage_Pool,
72 -- Present if result subtype is unconstrained or tagged. If
73 -- BIP_Alloc_Form = User_Storage_Pool, this is a pointer to the pool
74 -- (of type access to Root_Storage_Pool'Class). Otherwise null.
75
76 BIP_Finalization_Master,
77 -- Present if result type needs finalization. Pointer to caller's
78 -- finalization master.
79
80 BIP_Task_Master,
81 -- Present if result type contains tasks. Master associated with
82 -- calling context.
83
84 BIP_Activation_Chain,
85 -- Present if result type contains tasks. Caller's activation chain
86
87 BIP_Object_Access);
88 -- Present for all build-in-place functions. Address at which to place
89 -- the return object, or null if BIP_Alloc_Form indicates allocated by
90 -- callee.
91 --
92 -- ??? We might also need to be able to pass in a constrained flag.
93
94 procedure Add_Extra_Actual_To_Call
95 (Subprogram_Call : Node_Id;
96 Extra_Formal : Entity_Id;
97 Extra_Actual : Node_Id);
98 -- Adds Extra_Actual as a named parameter association for the formal
99 -- Extra_Formal in Subprogram_Call.
100
101 function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String;
102 -- Ada 2005 (AI-318-02): Returns a string to be used as the suffix of names
103 -- for build-in-place formal parameters of the given kind.
104
105 function Build_In_Place_Formal
106 (Func : Entity_Id;
107 Kind : BIP_Formal_Kind) return Entity_Id;
108 -- Ada 2005 (AI-318-02): Locates and returns the entity for the implicit
109 -- build-in-place formal parameter of the given kind associated with the
110 -- function Func, and returns its Entity_Id. It is a bug if not found; the
111 -- caller should ensure this is called only when the extra formal exists.
112
113 function Build_Procedure_Body_Form
114 (Func_Id : Entity_Id; Func_Body : Node_Id) return Node_Id;
115 -- Create a procedure body which emulates the behavior of function Func_Id.
116 -- Func_Body is the root of the body of the function before its analysis.
117 -- The returned node is the root of the procedure body which will replace
118 -- the original function body, which is not needed for the C program.
119
120 function Is_Build_In_Place_Function (E : Entity_Id) return Boolean;
121 -- Ada 2005 (AI-318-02): Returns True if E denotes a function, generic
122 -- function, or access-to-function type whose result must be built in
123 -- place; otherwise returns False. For Ada 2005, this is currently
124 -- restricted to the set of functions whose result subtype is an inherently
125 -- limited type. In Ada 95, this must be False for inherently limited
126 -- result types (but currently returns False for all Ada 95 functions).
127 -- Eventually we plan to support build-in-place for nonlimited types.
128 -- Build-in-place is usually more efficient for large things, and less
129 -- efficient for small things. However, we never use build-in-place if the
130 -- convention is other than Ada, because that would disturb mixed-language
131 -- programs. Note that for the non-inherently-limited cases, we must make
132 -- the same decision for Ada 95 and 2005, so that mixed-dialect programs
133 -- will work.
134
135 function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean;
136 -- Ada 2005 (AI-318-02): Returns True if N denotes a call to a function
137 -- that requires handling as a build-in-place call or is a qualified
138 -- expression applied to such a call; otherwise returns False.
139
140 function Is_Null_Procedure (Subp : Entity_Id) return Boolean;
141 -- Predicate to recognize stubbed procedures and null procedures, which
142 -- can be inlined unconditionally in all cases.
143
144 procedure Make_Build_In_Place_Call_In_Allocator
145 (Allocator : Node_Id;
146 Function_Call : Node_Id);
147 -- Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
148 -- occurs as the expression initializing an allocator, by passing access
149 -- to the allocated object as an additional parameter of the function call.
150 -- A new access object is declared that is initialized to the result of the
151 -- allocator, passed to the function, and the allocator is rewritten to
152 -- refer to that access object. Function_Call must denote either an
153 -- N_Function_Call node for which Is_Build_In_Place_Call is True, or else
154 -- an N_Qualified_Expression node applied to such a function call.
155
156 procedure Make_Build_In_Place_Call_In_Anonymous_Context
157 (Function_Call : Node_Id);
158 -- Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
159 -- occurs in a context that does not provide a separate object. A temporary
160 -- object is created to act as the return object and an access to the
161 -- temporary is passed as an additional parameter of the call. This occurs
162 -- in contexts such as subprogram call actuals and object renamings.
163 -- Function_Call must denote either an N_Function_Call node for which
164 -- Is_Build_In_Place_Call is True, or else an N_Qualified_Expression node
165 -- applied to such a function call.
166
167 procedure Make_Build_In_Place_Call_In_Assignment
168 (Assign : Node_Id;
169 Function_Call : Node_Id);
170 -- Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
171 -- occurs as the right-hand side of an assignment statement by passing
172 -- access to the left-hand side as an additional parameter of the function
173 -- call. Assign must denote a N_Assignment_Statement. Function_Call must
174 -- denote either an N_Function_Call node for which Is_Build_In_Place_Call
175 -- is True, or an N_Qualified_Expression node applied to such a function
176 -- call.
177
178 procedure Make_Build_In_Place_Call_In_Object_Declaration
179 (Obj_Decl : Node_Id;
180 Function_Call : Node_Id);
181 -- Ada 2005 (AI-318-02): Handle a call to a build-in-place function that
182 -- occurs as the expression initializing an object declaration by
183 -- passing access to the declared object as an additional parameter of the
184 -- function call. Function_Call must denote either an N_Function_Call node
185 -- for which Is_Build_In_Place_Call is True, or an N_Qualified_Expression
186 -- node applied to such a function call.
187
188 procedure Make_CPP_Constructor_Call_In_Allocator
189 (Allocator : Node_Id;
190 Function_Call : Node_Id);
191 -- Handle a call to a CPP constructor that occurs as the expression that
192 -- initializes an allocator, by passing access to the allocated object as
193 -- an additional parameter of the constructor call. A new access object is
194 -- declared that is initialized to the result of the allocator, passed to
195 -- the constructor, and the allocator is rewritten to refer to that access
196 -- object. Function_Call must denote a call to a CPP_Constructor function.
197
198 function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean;
199 -- Ada 2005 (AI-318-02): Return True if the function needs an implicit
200 -- BIP_Alloc_Form parameter (see type BIP_Formal_Kind).
201
202 function Needs_BIP_Finalization_Master (Func_Id : Entity_Id) return Boolean;
203 -- Ada 2005 (AI-318-02): Return True if the result subtype of function
204 -- Func_Id needs finalization actions.
205
206 function Needs_Result_Accessibility_Level
207 (Func_Id : Entity_Id) return Boolean;
208 -- Ada 2012 (AI05-0234): Return True if the function needs an implicit
209 -- parameter to identify the accessibility level of the function result
210 -- "determined by the point of call".
211
212 end Exp_Ch6;