1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
10 -- Copyright (C) 1992-2002 Free Software Foundation, Inc. --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- GNAT was originally developed by the GNAT team at New York University. --
24 -- Extensive contributions were provided by Ada Core Technologies Inc. --
26 ------------------------------------------------------------------------------
28 with Types
; use Types
;
29 with Uintp
; use Uintp
;
32 procedure Analyze_At_Clause
(N
: Node_Id
);
33 procedure Analyze_Attribute_Definition_Clause
(N
: Node_Id
);
34 procedure Analyze_Enumeration_Representation_Clause
(N
: Node_Id
);
35 procedure Analyze_Free_Statement
(N
: Node_Id
);
36 procedure Analyze_Record_Representation_Clause
(N
: Node_Id
);
37 procedure Analyze_Code_Statement
(N
: Node_Id
);
40 -- Initialize internal tables for new compilation
42 procedure Set_Enum_Esize
(T
: Entity_Id
);
43 -- This routine sets the Esize field for an enumeration type T, based
44 -- on the current representation information available for T. Note that
45 -- the setting of the RM_Size field is not affected. This routine also
46 -- initializes the alignment field to zero.
50 Biased
: Boolean := False)
52 -- Given a primitive type, determines the minimum number of bits required
53 -- to represent all values of the type. This function may not be called
54 -- with any other types. If the flag Biased is set True, then the minimum
55 -- size calculation that biased representation is used in the case of a
56 -- discrete type, e.g. the range 7..8 gives a minimum size of 4 with
57 -- Biased set to False, and 1 with Biased set to True. Note that the
58 -- biased parameter only has an effect if the type is not biased, it
59 -- causes Minimum_Size to indicate the minimum size of an object with
60 -- the given type, of the size the type would have if it were biased. If
61 -- the type is already biased, then Minimum_Size returns the biased size,
62 -- regardless of the setting of Biased. Also, fixed-point types are never
63 -- biased in the current implementation.
69 Biased
: out Boolean);
70 -- Called when size Siz is specified for subtype T. This subprogram checks
71 -- that the size is appropriate, posting errors on node N as required.
72 -- For non-elementary types, a check is only made if an explicit size
73 -- has been given for the type (and the specified size must match). The
74 -- parameter Biased is set False if the size specified did not require
75 -- the use of biased representation, and True if biased representation
76 -- was required to meet the size requirement. Note that Biased is only
77 -- set if the type is not currently biased, but biasing it is the only
78 -- way to meet the requirement. If the type is currently biased, then
79 -- this biased size is used in the initial check, and Biased is False.
81 procedure Record_Rep_Item
(T
: Entity_Id
; N
: Node_Id
);
82 -- N is the node for either a representation pragma or an attribute
83 -- definition clause that applies to type T. This procedure links
84 -- the node N onto the Rep_Item chain for the type T.
86 function Rep_Item_Too_Early
90 -- Called at the start of processing a representation clause or a
91 -- representation pragma. Used to check that the representation item
92 -- is not being applied to an incompleted type or to a generic formal
93 -- type or a type derived from a generic formal type. Returns False if
94 -- no such error occurs. If this error does occur, appropriate error
95 -- messages are posted on node N, and True is returned.
97 function Rep_Item_Too_Late
100 FOnly
: Boolean := False)
102 -- Called at the start of processing a representation clause or a
103 -- representation pragma. Used to check that a representation item
104 -- for entity T does not appear too late (according to the rules in
105 -- RM 13.1(9) and RM 13.1(10)). N is the associated node, which in
106 -- the pragma case is the pragma or representation clause itself, used
107 -- for placing error messages if the item is too late.
109 -- Fonly is a flag that causes only the freezing rule (para 9) to be
110 -- applied, and the tests of para 10 are skipped. This is appropriate
111 -- for both subtype related attributes (Alignment and Size) and for
112 -- stream attributes, which, although certainly not subtype related
113 -- attributes, clearly should not be subject to the para 10 restrictions
114 -- (see AI95-00137). Similarly, we also skip the para 10 restrictions for
115 -- the Storage_Size case where they also clearly do not apply.
117 -- If the rep item is too late, an appropriate message is output and
118 -- True is returned, which is a signal that the caller should abandon
119 -- processing for the item. If the item is not too late, then False
120 -- is returned, and the caller can continue processing the item.
122 -- If no error is detected, this call also as a side effect links the
123 -- representation item onto the head of the representation item chain
124 -- (referenced by the First_Rep_Item field of the entity).
126 -- Note: Rep_Item_Too_Late must be called with the underlying type in
127 -- the case of a private or incomplete type. The protocol is to first
128 -- check for Rep_Item_Too_Early using the initial entity, then take the
129 -- underlying type, then call Rep_Item_Too_Late on the result.
131 function Same_Representation
(Typ1
, Typ2
: Entity_Id
) return Boolean;
132 -- Given two types, where the two types are related by possible derivation,
133 -- determines if the two types have the same representation, or different
134 -- representations, requiring the special processing for representation
135 -- change. A False result is possible only for array, enumeration or
138 procedure Validate_Unchecked_Conversion
140 Act_Unit
: Entity_Id
);
141 -- Validate a call to unchecked conversion. N is the node for the actual
142 -- instantiation, which is used only for error messages. Act_Unit is the
143 -- entity for the instantiation, from which the actual types etc for this
144 -- instantiation can be determined. This procedure makes an entry in a
145 -- table and/or generates an N_Validate_Unchecked_Conversion node. The
146 -- actual checking is done in Validate_Unchecked_Conversions or in the
147 -- back end as required.
149 procedure Validate_Unchecked_Conversions
;
150 -- This routine is called after calling the backend to validate
151 -- unchecked conversions for size and alignment appropriateness.
152 -- The reason it is called that late is to take advantage of any
153 -- back-annotation of size and alignment performed by the backend.