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 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 (C : Id_Check := None) return Node_Id is
54 -- All set if we do indeed have an identifier
56 if Token = Tok_Identifier then
58 -- Ada 2005 (AI-284): Compiling in Ada95 mode we notify
59 -- that interface, overriding, and synchronized are
62 if Ada_Version = Ada_95 then
63 if Token_Name = Name_Overriding
64 or else Token_Name = Name_Synchronized
65 or else (Token_Name = Name_Interface
66 and then Prev_Token /= Tok_Pragma)
68 Error_Msg_N ("& is a reserved word in Ada 2005?", Token_Node);
72 Ident_Node := Token_Node;
73 Scan; -- past Identifier
76 -- If we have a reserved identifier, manufacture an identifier with
77 -- a corresponding name after posting an appropriate error message
79 elsif Is_Reserved_Identifier (C) then
80 Scan_Reserved_Identifier (Force_Msg => False);
81 Ident_Node := Token_Node;
82 Scan; -- past the node
85 -- Otherwise we have junk that cannot be interpreted as an identifier
88 T_Identifier; -- to give message
93 --------------------------
94 -- 2.3 Letter Or Digit --
95 --------------------------
97 -- Parsed by P_Identifier (2.3)
99 --------------------------
100 -- 2.4 Numeric Literal --
101 --------------------------
103 -- NUMERIC_LITERAL ::= DECIMAL_LITERAL | BASED_LITERAL
105 -- Numeric literal is returned by the scanner as either
106 -- Tok_Integer_Literal or Tok_Real_Literal
108 ----------------------------
109 -- 2.4.1 Decimal Literal --
110 ----------------------------
112 -- DECIMAL_LITERAL ::= NUMERAL [.NUMERAL] [EXPONENT]
114 -- Handled by scanner as part of numeric lIteral handing (see 2.4)
120 -- NUMERAL ::= DIGIT {[UNDERLINE] DIGIT}
122 -- Handled by scanner as part of numeric literal handling (see 2.4)
124 ---------------------
126 ---------------------
128 -- EXPONENT ::= E [+] NUMERAL | E - NUMERAL
130 -- Handled by scanner as part of numeric literal handling (see 2.4)
132 --------------------------
133 -- 2.4.2 Based Literal --
134 --------------------------
137 -- BASE # BASED_NUMERAL [.BASED_NUMERAL] # [EXPONENT]
139 -- Handled by scanner as part of numeric literal handling (see 2.4)
147 -- Handled by scanner as part of numeric literal handling (see 2.4)
149 --------------------------
150 -- 2.4.2 Based Numeral --
151 --------------------------
154 -- EXTENDED_DIGIT {[UNDERLINE] EXTENDED_DIGIT}
156 -- Handled by scanner as part of numeric literal handling (see 2.4)
158 ---------------------------
159 -- 2.4.2 Extended Digit --
160 ---------------------------
162 -- EXTENDED_DIGIT ::= DIGIT | A | B | C | D | E | F
164 -- Handled by scanner as part of numeric literal handling (see 2.4)
166 ----------------------------
167 -- 2.5 Character Literal --
168 ----------------------------
170 -- CHARACTER_LITERAL ::= ' GRAPHIC_CHARACTER '
172 -- Handled by the scanner and returned as Tok_Character_Literal
174 -------------------------
175 -- 2.6 String Literal --
176 -------------------------
178 -- STRING LITERAL ::= "{STRING_ELEMENT}"
180 -- Handled by the scanner and returned as Tok_Character_Literal
181 -- or if the string looks like an operator as Tok_Operator_Symbol.
183 -------------------------
184 -- 2.6 String Element --
185 -------------------------
187 -- STRING_ELEMENT ::= "" | non-quotation_mark_GRAPHIC_CHARACTER
189 -- A STRING_ELEMENT is either a pair of quotation marks ("),
190 -- or a single GRAPHIC_CHARACTER other than a quotation mark.
192 -- Handled by scanner as part of string literal handling (see 2.4)
198 -- A COMMENT starts with two adjacent hyphens and extends up to the
199 -- end of the line. A COMMENT may appear on any line of a program.
201 -- Handled by the scanner which simply skips past encountered comments
207 -- PRAGMA ::= pragma IDENTIFIER
208 -- [(PRAGMA_ARGUMENT_ASSOCIATION {, PRAGMA_ARGUMENT_ASSOCIATION})];
210 -- The caller has checked that the initial token is PRAGMA
212 -- Error recovery: cannot raise Error_Resync
214 -- One special piece of processing is needed in this routine. As described
215 -- in the section on "Handling semicolon used in place of IS" in module
216 -- Parse, the parser detects the case of missing subprogram bodies to
217 -- allow recovery from this syntactic error. Pragma INTERFACE (and, for
218 -- Ada 95, pragma IMPORT) can appear in place of the body. The parser must
219 -- recognize the use of these two pragmas in this context, otherwise it
220 -- will think there are missing bodies, and try to change ; to IS, when
221 -- in fact the bodies ARE present, supplied by these pragmas.
223 function P_Pragma return Node_Id is
225 Interface_Check_Required : Boolean := False;
226 -- Set True if check of pragma INTERFACE is required
228 Import_Check_Required : Boolean := False;
229 -- Set True if check of pragma IMPORT is required
231 Arg_Count : Int := 0;
232 -- Number of argument associations processed
234 Pragma_Node : Node_Id;
235 Pragma_Name : Name_Id;
236 Semicolon_Loc : Source_Ptr;
237 Ident_Node : Node_Id;
238 Assoc_Node : Node_Id;
241 procedure Skip_Pragma_Semicolon;
242 -- Skip past semicolon at end of pragma
244 ---------------------------
245 -- Skip_Pragma_Semicolon --
246 ---------------------------
248 procedure Skip_Pragma_Semicolon is
250 if Token /= Tok_Semicolon then
252 Resync_Past_Semicolon;
254 Scan; -- past semicolon
256 end Skip_Pragma_Semicolon;
258 -- Start of processing for P_Pragma
261 Pragma_Node := New_Node (N_Pragma, Token_Ptr);
263 Pragma_Name := Token_Name;
266 Style.Check_Pragma_Name;
269 -- Ada 2005 (AI-284): INTERFACE is a new reserved word but it is
270 -- allowed as a pragma name.
272 if Ada_Version >= Ada_05
273 and then Token = Tok_Interface
275 Pragma_Name := Name_Interface;
276 Ident_Node := Token_Node;
277 Scan; -- past INTERFACE
279 Ident_Node := P_Identifier;
280 Delete_Node (Ident_Node);
283 Set_Chars (Pragma_Node, Pragma_Name);
285 -- See if special INTERFACE/IMPORT check is required
287 if SIS_Entry_Active then
288 Interface_Check_Required := (Pragma_Name = Name_Interface);
289 Import_Check_Required := (Pragma_Name = Name_Import);
291 Interface_Check_Required := False;
292 Import_Check_Required := False;
295 -- Scan arguments. We assume that arguments are present if there is
296 -- a left paren, or if a semicolon is missing and there is another
297 -- token on the same line as the pragma name.
299 if Token = Tok_Left_Paren
300 or else (Token /= Tok_Semicolon
301 and then not Token_Is_At_Start_Of_Line)
303 Set_Pragma_Argument_Associations (Pragma_Node, New_List);
307 Arg_Count := Arg_Count + 1;
308 Assoc_Node := P_Pragma_Argument_Association;
311 and then (Interface_Check_Required or else Import_Check_Required)
313 -- Here is where we cancel the SIS active status if this pragma
314 -- supplies a body for the currently active subprogram spec.
316 if Nkind (Expression (Assoc_Node)) in N_Direct_Name
317 and then Chars (Expression (Assoc_Node)) = Chars (SIS_Labl)
319 SIS_Entry_Active := False;
323 Append (Assoc_Node, Pragma_Argument_Associations (Pragma_Node));
324 exit when Token /= Tok_Comma;
328 -- If we have := for pragma Debug, it is worth special casing
329 -- the error message (it is easy to think of pragma Debug as
330 -- taking a statement, and an assignment statement is the most
331 -- likely candidate for this error)
333 if Token = Tok_Colon_Equal and then Pragma_Name = Name_Debug then
334 Error_Msg_SC ("argument for pragma Debug must be procedure call");
337 -- Normal case, we expect a right paren here
344 Semicolon_Loc := Token_Ptr;
346 -- Now we have two tasks left, we need to scan out the semicolon
347 -- following the pragma, and we have to call Par.Prag to process
348 -- the pragma. Normally we do them in this order, however, there
349 -- is one exception namely pragma Style_Checks where we like to
350 -- skip the semicolon after processing the pragma, since that way
351 -- the style checks for the scanning of the semicolon follow the
352 -- settings of the pragma.
354 -- You might think we could just unconditionally do things in
355 -- the opposite order, but there are other pragmas, notably the
356 -- case of pragma Source_File_Name, which assume the semicolon
357 -- is already scanned out.
359 if Chars (Pragma_Node) = Name_Style_Checks then
360 Result := Par.Prag (Pragma_Node, Semicolon_Loc);
361 Skip_Pragma_Semicolon;
364 Skip_Pragma_Semicolon;
365 return Par.Prag (Pragma_Node, Semicolon_Loc);
370 Resync_Past_Semicolon;
375 -- This routine is called if a pragma is encountered in an inappropriate
376 -- position, the pragma is scanned out and control returns to continue.
378 -- The caller has checked that the initial token is pragma
380 -- Error recovery: cannot raise Error_Resync
382 procedure P_Pragmas_Misplaced is
384 while Token = Tok_Pragma loop
385 Error_Msg_SC ("pragma not allowed here");
386 Discard_Junk_Node (P_Pragma);
388 end P_Pragmas_Misplaced;
390 -- This function is called to scan out an optional sequence of pragmas.
391 -- If no pragmas are found, then No_List is returned.
393 -- Error recovery: Cannot raise Error_Resync
395 function P_Pragmas_Opt return List_Id is
399 if Token = Tok_Pragma then
409 -- This procedure is called to scan out an optional sequence of pragmas.
410 -- Any pragmas found are appended to the list provided as an argument.
412 -- Error recovery: Cannot raise Error_Resync
414 procedure P_Pragmas_Opt (List : List_Id) is
418 while Token = Tok_Pragma loop
421 if Chars (P) = Name_Assert or else Chars (P) = Name_Debug then
422 Error_Msg_Name_1 := Chars (P);
424 ("pragma% must be in declaration/statement context", P);
431 --------------------------------------
432 -- 2.8 Pragma_Argument Association --
433 --------------------------------------
435 -- PRAGMA_ARGUMENT_ASSOCIATION ::=
436 -- [pragma_argument_IDENTIFIER =>] NAME
437 -- | [pragma_argument_IDENTIFIER =>] EXPRESSION
439 -- Error recovery: cannot raise Error_Resync
441 function P_Pragma_Argument_Association return Node_Id is
442 Scan_State : Saved_Scan_State;
443 Pragma_Arg_Node : Node_Id;
444 Identifier_Node : Node_Id;
447 Pragma_Arg_Node := New_Node (N_Pragma_Argument_Association, Token_Ptr);
448 Set_Chars (Pragma_Arg_Node, No_Name);
450 if Token = Tok_Identifier then
451 Identifier_Node := Token_Node;
452 Save_Scan_State (Scan_State); -- at Identifier
453 Scan; -- past Identifier
455 if Token = Tok_Arrow then
457 Set_Chars (Pragma_Arg_Node, Chars (Identifier_Node));
458 Delete_Node (Identifier_Node);
460 Restore_Scan_State (Scan_State); -- to Identifier
464 Set_Expression (Pragma_Arg_Node, P_Expression);
465 return Pragma_Arg_Node;
467 end P_Pragma_Argument_Association;