1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003 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 pragma Style_Checks (All_Checks);
28 -- Turn off subprogram body ordering check. Subprograms are in order
29 -- by RM section rather than alphabetical
34 -- Local functions, used only in this chapter
36 function P_Pragma_Argument_Association return Node_Id;
42 -- IDENTIFIER ::= LETTER {[UNDERLINE] LETTER_OR_DIGIT}
44 -- LETTER_OR_DIGIT ::= IDENTIFIER_LETTER | DIGIT
46 -- An IDENTIFIER shall not be a reserved word
48 -- Error recovery: can raise Error_Resync (cannot return Error)
50 function P_Identifier return Node_Id is
54 -- All set if we do indeed have an identifier
56 if Token = Tok_Identifier then
57 Ident_Node := Token_Node;
58 Scan; -- past Identifier
61 -- If we have a reserved identifier, manufacture an identifier with
62 -- a corresponding name after posting an appropriate error message
64 elsif Is_Reserved_Identifier then
65 Scan_Reserved_Identifier (Force_Msg => False);
66 Ident_Node := Token_Node;
67 Scan; -- past the node
70 -- Otherwise we have junk that cannot be interpreted as an identifier
73 T_Identifier; -- to give message
78 --------------------------
79 -- 2.3 Letter Or Digit --
80 --------------------------
82 -- Parsed by P_Identifier (2.3)
84 --------------------------
85 -- 2.4 Numeric Literal --
86 --------------------------
88 -- NUMERIC_LITERAL ::= DECIMAL_LITERAL | BASED_LITERAL
90 -- Numeric literal is returned by the scanner as either
91 -- Tok_Integer_Literal or Tok_Real_Literal
93 ----------------------------
94 -- 2.4.1 Decimal Literal --
95 ----------------------------
97 -- DECIMAL_LITERAL ::= NUMERAL [.NUMERAL] [EXPONENT]
99 -- Handled by scanner as part of numeric lIteral handing (see 2.4)
105 -- NUMERAL ::= DIGIT {[UNDERLINE] DIGIT}
107 -- Handled by scanner as part of numeric literal handling (see 2.4)
109 ---------------------
111 ---------------------
113 -- EXPONENT ::= E [+] NUMERAL | E - NUMERAL
115 -- Handled by scanner as part of numeric literal handling (see 2.4)
117 --------------------------
118 -- 2.4.2 Based Literal --
119 --------------------------
122 -- BASE # BASED_NUMERAL [.BASED_NUMERAL] # [EXPONENT]
124 -- Handled by scanner as part of numeric literal handling (see 2.4)
132 -- Handled by scanner as part of numeric literal handling (see 2.4)
134 --------------------------
135 -- 2.4.2 Based Numeral --
136 --------------------------
139 -- EXTENDED_DIGIT {[UNDERLINE] EXTENDED_DIGIT}
141 -- Handled by scanner as part of numeric literal handling (see 2.4)
143 ---------------------------
144 -- 2.4.2 Extended Digit --
145 ---------------------------
147 -- EXTENDED_DIGIT ::= DIGIT | A | B | C | D | E | F
149 -- Handled by scanner as part of numeric literal handling (see 2.4)
151 ----------------------------
152 -- 2.5 Character Literal --
153 ----------------------------
155 -- CHARACTER_LITERAL ::= ' GRAPHIC_CHARACTER '
157 -- Handled by the scanner and returned as Tok_Character_Literal
159 -------------------------
160 -- 2.6 String Literal --
161 -------------------------
163 -- STRING LITERAL ::= "{STRING_ELEMENT}"
165 -- Handled by the scanner and returned as Tok_Character_Literal
166 -- or if the string looks like an operator as Tok_Operator_Symbol.
168 -------------------------
169 -- 2.6 String Element --
170 -------------------------
172 -- STRING_ELEMENT ::= "" | non-quotation_mark_GRAPHIC_CHARACTER
174 -- A STRING_ELEMENT is either a pair of quotation marks ("),
175 -- or a single GRAPHIC_CHARACTER other than a quotation mark.
177 -- Handled by scanner as part of string literal handling (see 2.4)
183 -- A COMMENT starts with two adjacent hyphens and extends up to the
184 -- end of the line. A COMMENT may appear on any line of a program.
186 -- Handled by the scanner which simply skips past encountered comments
192 -- PRAGMA ::= pragma IDENTIFIER
193 -- [(PRAGMA_ARGUMENT_ASSOCIATION {, PRAGMA_ARGUMENT_ASSOCIATION})];
195 -- The caller has checked that the initial token is PRAGMA
197 -- Error recovery: cannot raise Error_Resync
199 -- One special piece of processing is needed in this routine. As described
200 -- in the section on "Handling semicolon used in place of IS" in module
201 -- Parse, the parser detects the case of missing subprogram bodies to
202 -- allow recovery from this syntactic error. Pragma INTERFACE (and, for
203 -- Ada 95, pragma IMPORT) can appear in place of the body. The parser must
204 -- recognize the use of these two pragmas in this context, otherwise it
205 -- will think there are missing bodies, and try to change ; to IS, when
206 -- in fact the bodies ARE present, supplied by these pragmas.
208 function P_Pragma return Node_Id is
210 Interface_Check_Required : Boolean := False;
211 -- Set True if check of pragma INTERFACE is required
213 Import_Check_Required : Boolean := False;
214 -- Set True if check of pragma IMPORT is required
216 Arg_Count : Int := 0;
217 -- Number of argument associations processed
219 Pragma_Node : Node_Id;
220 Pragma_Name : Name_Id;
221 Semicolon_Loc : Source_Ptr;
222 Ident_Node : Node_Id;
223 Assoc_Node : Node_Id;
226 procedure Skip_Pragma_Semicolon;
227 -- Skip past semicolon at end of pragma
229 ---------------------------
230 -- Skip_Pragma_Semicolon --
231 ---------------------------
233 procedure Skip_Pragma_Semicolon is
235 if Token /= Tok_Semicolon then
237 Resync_Past_Semicolon;
239 Scan; -- past semicolon
241 end Skip_Pragma_Semicolon;
243 -- Start of processing for P_Pragma
246 Pragma_Node := New_Node (N_Pragma, Token_Ptr);
248 Pragma_Name := Token_Name;
251 Style.Check_Pragma_Name;
254 Ident_Node := P_Identifier;
255 Set_Chars (Pragma_Node, Pragma_Name);
256 Delete_Node (Ident_Node);
258 -- See if special INTERFACE/IMPORT check is required
260 if SIS_Entry_Active then
261 Interface_Check_Required := (Pragma_Name = Name_Interface);
262 Import_Check_Required := (Pragma_Name = Name_Import);
264 Interface_Check_Required := False;
265 Import_Check_Required := False;
268 -- Scan arguments. We assume that arguments are present if there is
269 -- a left paren, or if a semicolon is missing and there is another
270 -- token on the same line as the pragma name.
272 if Token = Tok_Left_Paren
273 or else (Token /= Tok_Semicolon
274 and then not Token_Is_At_Start_Of_Line)
276 Set_Pragma_Argument_Associations (Pragma_Node, New_List);
280 Arg_Count := Arg_Count + 1;
281 Assoc_Node := P_Pragma_Argument_Association;
284 and then (Interface_Check_Required or else Import_Check_Required)
286 -- Here is where we cancel the SIS active status if this pragma
287 -- supplies a body for the currently active subprogram spec.
289 if Nkind (Expression (Assoc_Node)) in N_Direct_Name
290 and then Chars (Expression (Assoc_Node)) = Chars (SIS_Labl)
292 SIS_Entry_Active := False;
296 Append (Assoc_Node, Pragma_Argument_Associations (Pragma_Node));
297 exit when Token /= Tok_Comma;
301 -- If we have := for pragma Debug, it is worth special casing
302 -- the error message (it is easy to think of pragma Debug as
303 -- taking a statement, and an assignment statement is the most
304 -- likely candidate for this error)
306 if Token = Tok_Colon_Equal and then Pragma_Name = Name_Debug then
307 Error_Msg_SC ("argument for pragma Debug must be procedure call");
310 -- Normal case, we expect a right paren here
317 Semicolon_Loc := Token_Ptr;
319 -- Now we have two tasks left, we need to scan out the semicolon
320 -- following the pragma, and we have to call Par.Prag to process
321 -- the pragma. Normally we do them in this order, however, there
322 -- is one exception namely pragma Style_Checks where we like to
323 -- skip the semicolon after processing the pragma, since that way
324 -- the style checks for the scanning of the semicolon follow the
325 -- settings of the pragma.
327 -- You might think we could just unconditionally do things in
328 -- the opposite order, but there are other pragmas, notably the
329 -- case of pragma Source_File_Name, which assume the semicolon
330 -- is already scanned out.
332 if Chars (Pragma_Node) = Name_Style_Checks then
333 Result := Par.Prag (Pragma_Node, Semicolon_Loc);
334 Skip_Pragma_Semicolon;
337 Skip_Pragma_Semicolon;
338 return Par.Prag (Pragma_Node, Semicolon_Loc);
343 Resync_Past_Semicolon;
348 -- This routine is called if a pragma is encountered in an inappropriate
349 -- position, the pragma is scanned out and control returns to continue.
351 -- The caller has checked that the initial token is pragma
353 -- Error recovery: cannot raise Error_Resync
355 procedure P_Pragmas_Misplaced is
357 while Token = Tok_Pragma loop
358 Error_Msg_SC ("pragma not allowed here");
359 Discard_Junk_Node (P_Pragma);
361 end P_Pragmas_Misplaced;
363 -- This function is called to scan out an optional sequence of pragmas.
364 -- If no pragmas are found, then No_List is returned.
366 -- Error recovery: Cannot raise Error_Resync
368 function P_Pragmas_Opt return List_Id is
372 if Token = Tok_Pragma then
382 -- This procedure is called to scan out an optional sequence of pragmas.
383 -- Any pragmas found are appended to the list provided as an argument.
385 -- Error recovery: Cannot raise Error_Resync
387 procedure P_Pragmas_Opt (List : List_Id) is
391 while Token = Tok_Pragma loop
394 if Chars (P) = Name_Assert or else Chars (P) = Name_Debug then
395 Error_Msg_Name_1 := Chars (P);
397 ("pragma% must be in declaration/statement context", P);
404 --------------------------------------
405 -- 2.8 Pragma_Argument Association --
406 --------------------------------------
408 -- PRAGMA_ARGUMENT_ASSOCIATION ::=
409 -- [pragma_argument_IDENTIFIER =>] NAME
410 -- | [pragma_argument_IDENTIFIER =>] EXPRESSION
412 -- Error recovery: cannot raise Error_Resync
414 function P_Pragma_Argument_Association return Node_Id is
415 Scan_State : Saved_Scan_State;
416 Pragma_Arg_Node : Node_Id;
417 Identifier_Node : Node_Id;
420 Pragma_Arg_Node := New_Node (N_Pragma_Argument_Association, Token_Ptr);
421 Set_Chars (Pragma_Arg_Node, No_Name);
423 if Token = Tok_Identifier then
424 Identifier_Node := Token_Node;
425 Save_Scan_State (Scan_State); -- at Identifier
426 Scan; -- past Identifier
428 if Token = Tok_Arrow then
430 Set_Chars (Pragma_Arg_Node, Chars (Identifier_Node));
431 Delete_Node (Identifier_Node);
433 Restore_Scan_State (Scan_State); -- to Identifier
437 Set_Expression (Pragma_Arg_Node, P_Expression);
438 return Pragma_Arg_Node;
440 end P_Pragma_Argument_Association;