1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2002 Free Software Foundation, Inc. --
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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Types
; use Types
;
28 with Uintp
; use Uintp
;
31 procedure Analyze_At_Clause
(N
: Node_Id
);
32 procedure Analyze_Attribute_Definition_Clause
(N
: Node_Id
);
33 procedure Analyze_Enumeration_Representation_Clause
(N
: Node_Id
);
34 procedure Analyze_Free_Statement
(N
: Node_Id
);
35 procedure Analyze_Record_Representation_Clause
(N
: Node_Id
);
36 procedure Analyze_Code_Statement
(N
: Node_Id
);
39 -- Initialize internal tables for new compilation
41 procedure Set_Enum_Esize
(T
: Entity_Id
);
42 -- This routine sets the Esize field for an enumeration type T, based
43 -- on the current representation information available for T. Note that
44 -- the setting of the RM_Size field is not affected. This routine also
45 -- initializes the alignment field to zero.
49 Biased
: Boolean := False)
51 -- Given a primitive type, determines the minimum number of bits required
52 -- to represent all values of the type. This function may not be called
53 -- with any other types. If the flag Biased is set True, then the minimum
54 -- size calculation that biased representation is used in the case of a
55 -- discrete type, e.g. the range 7..8 gives a minimum size of 4 with
56 -- Biased set to False, and 1 with Biased set to True. Note that the
57 -- biased parameter only has an effect if the type is not biased, it
58 -- causes Minimum_Size to indicate the minimum size of an object with
59 -- the given type, of the size the type would have if it were biased. If
60 -- the type is already biased, then Minimum_Size returns the biased size,
61 -- regardless of the setting of Biased. Also, fixed-point types are never
62 -- biased in the current implementation.
68 Biased
: out Boolean);
69 -- Called when size Siz is specified for subtype T. This subprogram checks
70 -- that the size is appropriate, posting errors on node N as required.
71 -- For non-elementary types, a check is only made if an explicit size
72 -- has been given for the type (and the specified size must match). The
73 -- parameter Biased is set False if the size specified did not require
74 -- the use of biased representation, and True if biased representation
75 -- was required to meet the size requirement. Note that Biased is only
76 -- set if the type is not currently biased, but biasing it is the only
77 -- way to meet the requirement. If the type is currently biased, then
78 -- this biased size is used in the initial check, and Biased is False.
80 procedure Record_Rep_Item
(T
: Entity_Id
; N
: Node_Id
);
81 -- N is the node for either a representation pragma or an attribute
82 -- definition clause that applies to type T. This procedure links
83 -- the node N onto the Rep_Item chain for the type T.
85 function Rep_Item_Too_Early
89 -- Called at the start of processing a representation clause or a
90 -- representation pragma. Used to check that the representation item
91 -- is not being applied to an incompleted type or to a generic formal
92 -- type or a type derived from a generic formal type. Returns False if
93 -- no such error occurs. If this error does occur, appropriate error
94 -- messages are posted on node N, and True is returned.
96 function Rep_Item_Too_Late
99 FOnly
: Boolean := False)
101 -- Called at the start of processing a representation clause or a
102 -- representation pragma. Used to check that a representation item
103 -- for entity T does not appear too late (according to the rules in
104 -- RM 13.1(9) and RM 13.1(10)). N is the associated node, which in
105 -- the pragma case is the pragma or representation clause itself, used
106 -- for placing error messages if the item is too late.
108 -- Fonly is a flag that causes only the freezing rule (para 9) to be
109 -- applied, and the tests of para 10 are skipped. This is appropriate
110 -- for both subtype related attributes (Alignment and Size) and for
111 -- stream attributes, which, although certainly not subtype related
112 -- attributes, clearly should not be subject to the para 10 restrictions
113 -- (see AI95-00137). Similarly, we also skip the para 10 restrictions for
114 -- the Storage_Size case where they also clearly do not apply.
116 -- If the rep item is too late, an appropriate message is output and
117 -- True is returned, which is a signal that the caller should abandon
118 -- processing for the item. If the item is not too late, then False
119 -- is returned, and the caller can continue processing the item.
121 -- If no error is detected, this call also as a side effect links the
122 -- representation item onto the head of the representation item chain
123 -- (referenced by the First_Rep_Item field of the entity).
125 -- Note: Rep_Item_Too_Late must be called with the underlying type in
126 -- the case of a private or incomplete type. The protocol is to first
127 -- check for Rep_Item_Too_Early using the initial entity, then take the
128 -- underlying type, then call Rep_Item_Too_Late on the result.
130 function Same_Representation
(Typ1
, Typ2
: Entity_Id
) return Boolean;
131 -- Given two types, where the two types are related by possible derivation,
132 -- determines if the two types have the same representation, or different
133 -- representations, requiring the special processing for representation
134 -- change. A False result is possible only for array, enumeration or
137 procedure Validate_Unchecked_Conversion
139 Act_Unit
: Entity_Id
);
140 -- Validate a call to unchecked conversion. N is the node for the actual
141 -- instantiation, which is used only for error messages. Act_Unit is the
142 -- entity for the instantiation, from which the actual types etc for this
143 -- instantiation can be determined. This procedure makes an entry in a
144 -- table and/or generates an N_Validate_Unchecked_Conversion node. The
145 -- actual checking is done in Validate_Unchecked_Conversions or in the
146 -- back end as required.
148 procedure Validate_Unchecked_Conversions
;
149 -- This routine is called after calling the backend to validate
150 -- unchecked conversions for size and alignment appropriateness.
151 -- The reason it is called that late is to take advantage of any
152 -- back-annotation of size and alignment performed by the backend.