1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, 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 -- This package contains various utility procedures to assist in
28 -- building specific types of tree nodes.
30 with Types
; use Types
;
34 function Checks_Off
(N
: Node_Id
) return Node_Id
;
35 pragma Inline
(Checks_Off
);
36 -- Returns an N_Unchecked_Expression node whose expression is the given
37 -- argument. The results is a subexpression identical to the argument,
38 -- except that it will be analyzed and resolved with checks off.
40 function Convert_To
(Typ
: Entity_Id
; Expr
: Node_Id
) return Node_Id
;
41 -- Returns an expression that represents the result of a checked convert
42 -- of expression Exp to type T. If the base type of Exp is T, then no
43 -- conversion is required, and Exp is returned unchanged. Otherwise an
44 -- N_Type_Conversion node is constructed to convert the expression.
45 -- If an N_Type_Conversion node is required, Relocate_Node is used on
46 -- Exp. This means that it is safe to replace a node by a Convert_To
47 -- of itself to some other type.
49 procedure Discard_Node
(N
: Node_Or_Entity_Id
);
50 pragma Inline
(Discard_Node
);
51 -- This is a dummy procedure that simply returns and does nothing.
52 -- It is used when a function returning a Node_Id value is called
53 -- for its side effect (e.g. a call to Make to construct a node)
54 -- but the Node_Id value is not required.
56 procedure Discard_List
(L
: List_Id
);
57 pragma Inline
(Discard_List
);
58 -- This is a dummy procedure that simply returns and does nothing.
59 -- It is used when a function returning a Node_Id value is called
60 -- for its side effect (e.g. a call to the pareser to parse a list
61 -- of compilation units), but the List_Id value is not required.
63 function Make_Byte_Aligned_Attribute_Reference
66 Attribute_Name
: Name_Id
) return Node_Id
;
67 pragma Inline
(Make_Byte_Aligned_Attribute_Reference
);
68 -- Like the standard Make_Attribute_Reference but the special flag
69 -- Must_Be_Byte_Aligned is set in the attribute reference node. The
70 -- Attribute_Name must be Name_Address or Name_Unrestricted_Access.
72 function Make_DT_Access
73 (Loc
: Source_Ptr
; Rec
: Node_Id
; Typ
: Entity_Id
) return Node_Id
;
74 -- Create an access to the Dispatch Table by using the Tag field
75 -- of a tagged record : Acc_Dt (Rec.tag).all
77 function Make_Implicit_If_Statement
80 Then_Statements
: List_Id
;
81 Elsif_Parts
: List_Id
:= No_List
;
82 Else_Statements
: List_Id
:= No_List
) return Node_Id
;
83 pragma Inline
(Make_Implicit_If_Statement
);
84 -- This function makes an N_If_Statement node whose fields are filled
85 -- in with the indicated values (see Sinfo), and whose Sloc field is
86 -- is set to Sloc (Node). The effect is identical to calling function
87 -- Nmake.Make_If_Statement except that there is a check for restriction
88 -- No_Implicit_Conditionals, and if this restriction is being violated,
89 -- an error message is posted on Node.
91 function Make_Implicit_Label_Declaration
93 Defining_Identifier
: Node_Id
;
94 Label_Construct
: Node_Id
) return Node_Id
;
95 -- Used to contruct an implicit label declaration node, including setting
96 -- the proper Label_Construct field (since Label_Construct is a semantic
97 -- field, the normal call to Make_Implicit_Label_Declaration does not
100 function Make_Implicit_Loop_Statement
102 Statements
: List_Id
;
103 Identifier
: Node_Id
:= Empty
;
104 Iteration_Scheme
: Node_Id
:= Empty
;
105 Has_Created_Identifier
: Boolean := False;
106 End_Label
: Node_Id
:= Empty
) return Node_Id
;
107 -- This function makes an N_Loop_Statement node whose fields are filled
108 -- in with the indicated values (see Sinfo), and whose Sloc field is
109 -- is set to Sloc (Node). The effect is identical to calling function
110 -- Nmake.Make_Loop_Statement except that there is a check for restrictions
111 -- No_Implicit_Loops and No_Implicit_Conditionals (the first applying in
112 -- all cases, and the second only for while loops), and if one of these
113 -- restrictions is being violated, an error message is posted on Node.
115 function Make_Integer_Literal
117 Intval
: Int
) return Node_Id
;
118 pragma Inline
(Make_Integer_Literal
);
119 -- A convenient form of Make_Integer_Literal taking Int instead of Uint
121 function Make_Raise_Constraint_Error
123 Condition
: Node_Id
:= Empty
;
124 Reason
: RT_Exception_Code
) return Node_Id
;
125 pragma Inline
(Make_Raise_Constraint_Error
);
126 -- A convenient form of Make_Raise_Constraint_Error where the Reason
127 -- is given simply as an enumeration value, rather than a Uint code.
129 function Make_Raise_Program_Error
131 Condition
: Node_Id
:= Empty
;
132 Reason
: RT_Exception_Code
) return Node_Id
;
133 pragma Inline
(Make_Raise_Program_Error
);
134 -- A convenient form of Make_Raise_Program_Error where the Reason
135 -- is given simply as an enumeration value, rather than a Uint code.
137 function Make_Raise_Storage_Error
139 Condition
: Node_Id
:= Empty
;
140 Reason
: RT_Exception_Code
) return Node_Id
;
141 pragma Inline
(Make_Raise_Storage_Error
);
142 -- A convenient form of Make_Raise_Storage_Error where the Reason
143 -- is given simply as an enumeration value, rather than a Uint code.
145 function Make_String_Literal
147 Strval
: String) return Node_Id
;
148 -- A convenient form of Make_String_Literal, where the string value
149 -- is given as a normal string instead of a String_Id value.
151 function Make_Unsuppress_Block
154 Stmts
: List_Id
) return Node_Id
;
155 -- Build a block with a pragma Suppress on 'Check'. Stmts is the
156 -- statements list that needs protection against the check
158 function New_Constraint_Error
(Loc
: Source_Ptr
) return Node_Id
;
159 -- This function builds a tree corresponding to the Ada statement
160 -- "raise Constraint_Error" and returns the root of this tree,
161 -- the N_Raise_Statement node.
163 function New_External_Name
164 (Related_Id
: Name_Id
;
165 Suffix
: Character := ' ';
166 Suffix_Index
: Int
:= 0;
167 Prefix
: Character := ' ') return Name_Id
;
168 function New_External_Name
169 (Related_Id
: Name_Id
;
171 Suffix_Index
: Int
:= 0;
172 Prefix
: Character := ' ') return Name_Id
;
173 -- Builds a new entry in the names table of the form:
175 -- [Prefix &] Related_Id [& Suffix] [& Suffix_Index]
177 -- Prefix is prepended only if Prefix is non-blank (in which case it
178 -- must be an upper case letter other than O,Q,U,W (which are used for
179 -- identifier encoding, see Namet), and T is reserved for use by implicit
180 -- types. and X is reserved for use by debug type encoding (see package
181 -- Exp_Dbug). Note: the reason that Prefix is last is that it is almost
182 -- always omitted. The notable case of Prefix being non-null is when
183 -- it is 'T' for an implicit type.
185 -- Suffix_Index'Image is appended only if the value of Suffix_Index is
186 -- positive, or if Suffix_Index is negative 1, then a unique serialized
187 -- suffix is added. If Suffix_Index is zero, then no index is appended.
189 -- Suffix is also a single upper case letter other than O,Q,U,W,X and is a
190 -- required parameter (T is permitted). The constructed name is stored
191 -- using Find_Name so that it can be located using a subsequent Find_Name
192 -- operation (i.e. it is properly hashed into the names table). The upper
193 -- case letter given as the Suffix argument ensures that the name does
194 -- not clash with any Ada identifier name. These generated names are
195 -- permitted, but not required, to be made public by setting the flag
196 -- Is_Public in the associated entity.
198 function New_External_Name
200 Suffix_Index
: Nat
) return Name_Id
;
201 -- Builds a new entry in the names table of the form
202 -- Suffix & Suffix_Index'Image
203 -- where Suffix is a single upper case letter other than O,Q,U,W,X and is
204 -- a required parameter (T is permitted). The constructed name is stored
205 -- using Find_Name so that it can be located using a subsequent Find_Name
206 -- operation (i.e. it is properly hashed into the names table). The upper
207 -- case letter given as the Suffix argument ensures that the name does
208 -- not clash with any Ada identifier name. These generated names are
209 -- permitted, but not required, to be made public by setting the flag
210 -- Is_Public in the associated entity.
212 function New_Internal_Name
(Id_Char
: Character) return Name_Id
;
213 -- Id_Char is an upper case letter other than O,Q,U,W (which are reserved
214 -- for identifier encoding (see Namet package for details) and X which is
215 -- used for debug encoding (see Exp_Dbug). The letter T is permitted, but
216 -- is reserved by convention for the case of internally generated types.
217 -- The result of the call is a new generated unique name of the form XyyyU
218 -- where X is Id_Char, yyy is a unique serial number, and U is either a
219 -- lower case s or b indicating if the current unit is a spec or a body.
221 -- The name is entered into the names table using Name_Enter rather than
222 -- Name_Find, because there can never be a need to locate the entry using
223 -- the Name_Find procedure later on. Names created by New_Internal_Name
224 -- are guaranteed to be consistent from one compilation to another (i.e.
225 -- if the identical unit is compiled with a semantically consistent set
226 -- of sources, the numbers will be consistent. This means that it is fine
227 -- to use these as public symbols.
229 function New_Occurrence_Of
231 Loc
: Source_Ptr
) return Node_Id
;
232 -- New_Occurrence_Of creates an N_Identifier node which is an
233 -- occurrence of the defining identifier which is passed as its
234 -- argument. The Entity and Etype of the result are set from
235 -- the given defining identifier as follows: Entity is simply
236 -- a copy of Def_Id. Etype is a copy of Def_Id for types, and
237 -- a copy of the Etype of Def_Id for other entities.
239 function New_Reference_To
241 Loc
: Source_Ptr
) return Node_Id
;
242 -- This is like New_Occurrence_Of, but it does not set the Etype field.
243 -- It is used from the expander, where Etype fields are generally not set,
244 -- since they are set when the expanded tree is reanalyzed.
246 function New_Suffixed_Name
247 (Related_Id
: Name_Id
;
248 Suffix
: String) return Name_Id
;
249 -- This function is used to create special suffixed names used by the
250 -- debugger. Suffix is a string of upper case letters, used to construct
251 -- the required name. For instance, the special type used to record the
252 -- fixed-point small is called typ_SMALL where typ is the name of the
253 -- fixed-point type (as passed in Related_Id), and Suffix is "SMALL".
255 function OK_Convert_To
(Typ
: Entity_Id
; Expr
: Node_Id
) return Node_Id
;
256 -- Like Convert_To, except that a conversion node is always generated,
257 -- and the Conversion_OK flag is set on this conversion node.
259 function Unchecked_Convert_To
261 Expr
: Node_Id
) return Node_Id
;
262 -- Like Convert_To, but if a conversion is actually needed, constructs
263 -- an N_Unchecked_Type_Conversion node to do the required conversion.