1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2006, 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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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);
38 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id);
39 -- Called from Freeze where R is a record entity for which reverse bit
40 -- order is specified and there is at least one component clause. Adjusts
41 -- component positions according to Ada 2005 AI-133. Note that this is only
42 -- called in Ada 2005 mode. The Ada 95 handling for bit order is entirely
43 -- contained in Freeze.
46 -- Initialize internal tables for new compilation
48 procedure Set_Enum_Esize (T : Entity_Id);
49 -- This routine sets the Esize field for an enumeration type T, based
50 -- on the current representation information available for T. Note that
51 -- the setting of the RM_Size field is not affected. This routine also
52 -- initializes the alignment field to zero.
56 Biased : Boolean := False) return Nat;
57 -- Given an elementary type, determines the minimum number of bits required
58 -- to represent all values of the type. This function may not be called
59 -- with any other types. If the flag Biased is set True, then the minimum
60 -- size calculation that biased representation is used in the case of a
61 -- discrete type, e.g. the range 7..8 gives a minimum size of 4 with
62 -- Biased set to False, and 1 with Biased set to True. Note that the
63 -- biased parameter only has an effect if the type is not biased, it
64 -- causes Minimum_Size to indicate the minimum size of an object with
65 -- the given type, of the size the type would have if it were biased. If
66 -- the type is already biased, then Minimum_Size returns the biased size,
67 -- regardless of the setting of Biased. Also, fixed-point types are never
68 -- biased in the current implementation.
70 procedure Check_Constant_Address_Clause (Expr : Node_Id; U_Ent : Entity_Id);
71 -- Expr is an expression for an address clause. This procedure checks
72 -- that the expression is constant, in the limited sense that it is safe
73 -- to evaluate it at the point the object U_Ent is declared, rather than
74 -- at the point of the address clause. The condition for this to be true
75 -- is that the expression has no variables, no constants declared after
76 -- U_Ent, and no calls to non-pure functions. If this condition is not
77 -- met, then an appropriate error message is posted. This check is applied
78 -- at the point an object with an address clause is frozen, as well as for
79 -- address clauses for tasks and entries.
85 Biased : out Boolean);
86 -- Called when size Siz is specified for subtype T. This subprogram checks
87 -- that the size is appropriate, posting errors on node N as required.
88 -- This check is effective for elementary types and bit-packed arrays.
89 -- For other non-elementary types, a check is only made if an explicit
90 -- size has been given for the type (and the specified size must match).
91 -- The parameter Biased is set False if the size specified did not require
92 -- the use of biased representation, and True if biased representation
93 -- was required to meet the size requirement. Note that Biased is only
94 -- set if the type is not currently biased, but biasing it is the only
95 -- way to meet the requirement. If the type is currently biased, then
96 -- this biased size is used in the initial check, and Biased is False.
97 -- If the size is too small, and an error message is given, then both
98 -- Esize and RM_Size are reset to the allowed minimum value in T.
100 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean;
101 -- Called at the start of processing a representation clause or a
102 -- representation pragma. Used to check that the representation item
103 -- is not being applied to an incompleted type or to a generic formal
104 -- type or a type derived from a generic formal type. Returns False if
105 -- no such error occurs. If this error does occur, appropriate error
106 -- messages are posted on node N, and True is returned.
108 function Rep_Item_Too_Late
111 FOnly : Boolean := False) return Boolean;
112 -- Called at the start of processing a representation clause or a
113 -- representation pragma. Used to check that a representation item
114 -- for entity T does not appear too late (according to the rules in
115 -- RM 13.1(9) and RM 13.1(10)). N is the associated node, which in
116 -- the pragma case is the pragma or representation clause itself, used
117 -- for placing error messages if the item is too late.
119 -- Fonly is a flag that causes only the freezing rule (para 9) to be
120 -- applied, and the tests of para 10 are skipped. This is appropriate
121 -- for both subtype related attributes (Alignment and Size) and for
122 -- stream attributes, which, although certainly not subtype related
123 -- attributes, clearly should not be subject to the para 10 restrictions
124 -- (see AI95-00137). Similarly, we also skip the para 10 restrictions for
125 -- the Storage_Size case where they also clearly do not apply.
127 -- If the rep item is too late, an appropriate message is output and
128 -- True is returned, which is a signal that the caller should abandon
129 -- processing for the item. If the item is not too late, then False
130 -- is returned, and the caller can continue processing the item.
132 -- If no error is detected, this call also as a side effect links the
133 -- representation item onto the head of the representation item chain
134 -- (referenced by the First_Rep_Item field of the entity).
136 -- Note: Rep_Item_Too_Late must be called with the underlying type in
137 -- the case of a private or incomplete type. The protocol is to first
138 -- check for Rep_Item_Too_Early using the initial entity, then take the
139 -- underlying type, then call Rep_Item_Too_Late on the result.
141 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean;
142 -- Given two types, where the two types are related by possible derivation,
143 -- determines if the two types have the same representation, or different
144 -- representations, requiring the special processing for representation
145 -- change. A False result is possible only for array, enumeration or
148 procedure Validate_Unchecked_Conversion
150 Act_Unit : Entity_Id);
151 -- Validate a call to unchecked conversion. N is the node for the actual
152 -- instantiation, which is used only for error messages. Act_Unit is the
153 -- entity for the instantiation, from which the actual types etc for this
154 -- instantiation can be determined. This procedure makes an entry in a
155 -- table and/or generates an N_Validate_Unchecked_Conversion node. The
156 -- actual checking is done in Validate_Unchecked_Conversions or in the
157 -- back end as required.
159 procedure Validate_Unchecked_Conversions;
160 -- This routine is called after calling the backend to validate
161 -- unchecked conversions for size and alignment appropriateness.
162 -- The reason it is called that late is to take advantage of any
163 -- back-annotation of size and alignment performed by the backend.