1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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 3, 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 pragma Style_Checks
(All_Checks
);
27 -- Turn off subprogram body ordering check. Subprograms are in order
28 -- by RM section rather than alphabetical
33 -- Local functions, used only in this chapter
35 procedure Scan_Pragma_Argument_Association
36 (Identifier_Seen
: in out Boolean;
37 Association
: out Node_Id
);
38 -- Scans out a pragma argument association. Identifier_Seen is true on
39 -- entry if a previous association had an identifier, and gets set True if
40 -- the scanned association has an identifier (this is used to check the
41 -- rule that no associations without identifiers can follow an association
42 -- which has an identifier). The result is returned in Association.
48 -- IDENTIFIER ::= LETTER {[UNDERLINE] LETTER_OR_DIGIT}
50 -- LETTER_OR_DIGIT ::= IDENTIFIER_LETTER | DIGIT
52 -- An IDENTIFIER shall not be a reserved word
54 -- Error recovery: can raise Error_Resync (cannot return Error)
56 function P_Identifier
(C
: Id_Check
:= None
) return Node_Id
is
60 -- All set if we do indeed have an identifier
62 if Token
= Tok_Identifier
then
64 -- Ada 2005 (AI-284): Compiling in Ada95 mode we warn that INTERFACE,
65 -- OVERRIDING, and SYNCHRONIZED are new reserved words.
67 if Ada_Version
= Ada_95
68 and then Warn_On_Ada_2005_Compatibility
70 if Token_Name
= Name_Overriding
71 or else Token_Name
= Name_Synchronized
72 or else (Token_Name
= Name_Interface
73 and then Prev_Token
/= Tok_Pragma
)
75 Error_Msg_N
("& is a reserved word in Ada 2005?", Token_Node
);
79 Ident_Node
:= Token_Node
;
80 Scan
; -- past Identifier
83 -- If we have a reserved identifier, manufacture an identifier with
84 -- a corresponding name after posting an appropriate error message
86 elsif Is_Reserved_Identifier
(C
) then
87 Scan_Reserved_Identifier
(Force_Msg
=> False);
88 Ident_Node
:= Token_Node
;
89 Scan
; -- past the node
92 -- Otherwise we have junk that cannot be interpreted as an identifier
95 T_Identifier
; -- to give message
100 --------------------------
101 -- 2.3 Letter Or Digit --
102 --------------------------
104 -- Parsed by P_Identifier (2.3)
106 --------------------------
107 -- 2.4 Numeric Literal --
108 --------------------------
110 -- NUMERIC_LITERAL ::= DECIMAL_LITERAL | BASED_LITERAL
112 -- Numeric literal is returned by the scanner as either
113 -- Tok_Integer_Literal or Tok_Real_Literal
115 ----------------------------
116 -- 2.4.1 Decimal Literal --
117 ----------------------------
119 -- DECIMAL_LITERAL ::= NUMERAL [.NUMERAL] [EXPONENT]
121 -- Handled by scanner as part of numeric literal handing (see 2.4)
127 -- NUMERAL ::= DIGIT {[UNDERLINE] DIGIT}
129 -- Handled by scanner as part of numeric literal handling (see 2.4)
131 ---------------------
133 ---------------------
135 -- EXPONENT ::= E [+] NUMERAL | E - NUMERAL
137 -- Handled by scanner as part of numeric literal handling (see 2.4)
139 --------------------------
140 -- 2.4.2 Based Literal --
141 --------------------------
144 -- BASE # BASED_NUMERAL [.BASED_NUMERAL] # [EXPONENT]
146 -- Handled by scanner as part of numeric literal handling (see 2.4)
154 -- Handled by scanner as part of numeric literal handling (see 2.4)
156 --------------------------
157 -- 2.4.2 Based Numeral --
158 --------------------------
161 -- EXTENDED_DIGIT {[UNDERLINE] EXTENDED_DIGIT}
163 -- Handled by scanner as part of numeric literal handling (see 2.4)
165 ---------------------------
166 -- 2.4.2 Extended Digit --
167 ---------------------------
169 -- EXTENDED_DIGIT ::= DIGIT | A | B | C | D | E | F
171 -- Handled by scanner as part of numeric literal handling (see 2.4)
173 ----------------------------
174 -- 2.5 Character Literal --
175 ----------------------------
177 -- CHARACTER_LITERAL ::= ' GRAPHIC_CHARACTER '
179 -- Handled by the scanner and returned as Tok_Char_Literal
181 -------------------------
182 -- 2.6 String Literal --
183 -------------------------
185 -- STRING LITERAL ::= "{STRING_ELEMENT}"
187 -- Handled by the scanner and returned as Tok_String_Literal
188 -- or if the string looks like an operator as Tok_Operator_Symbol.
190 -------------------------
191 -- 2.6 String Element --
192 -------------------------
194 -- STRING_ELEMENT ::= "" | non-quotation_mark_GRAPHIC_CHARACTER
196 -- A STRING_ELEMENT is either a pair of quotation marks ("),
197 -- or a single GRAPHIC_CHARACTER other than a quotation mark.
199 -- Handled by scanner as part of string literal handling (see 2.4)
205 -- A COMMENT starts with two adjacent hyphens and extends up to the
206 -- end of the line. A COMMENT may appear on any line of a program.
208 -- Handled by the scanner which simply skips past encountered comments
214 -- PRAGMA ::= pragma IDENTIFIER
215 -- [(PRAGMA_ARGUMENT_ASSOCIATION {, PRAGMA_ARGUMENT_ASSOCIATION})];
217 -- The caller has checked that the initial token is PRAGMA
219 -- Error recovery: cannot raise Error_Resync
221 -- One special piece of processing is needed in this routine. As described
222 -- in the section on "Handling semicolon used in place of IS" in module
223 -- Parse, the parser detects the case of missing subprogram bodies to
224 -- allow recovery from this syntactic error. Pragma INTERFACE (and, for
225 -- Ada 95, pragma IMPORT) can appear in place of the body. The parser must
226 -- recognize the use of these two pragmas in this context, otherwise it
227 -- will think there are missing bodies, and try to change ; to IS, when
228 -- in fact the bodies ARE present, supplied by these pragmas.
230 function P_Pragma
(Skipping
: Boolean := False) return Node_Id
is
231 Interface_Check_Required
: Boolean := False;
232 -- Set True if check of pragma INTERFACE is required
234 Import_Check_Required
: Boolean := False;
235 -- Set True if check of pragma IMPORT is required
237 Arg_Count
: Int
:= 0;
238 -- Number of argument associations processed
240 Identifier_Seen
: Boolean := False;
241 -- Set True if an identifier is encountered for a pragma argument. Used
242 -- to check that there are no more arguments without identifiers.
246 Semicolon_Loc
: Source_Ptr
;
247 Ident_Node
: Node_Id
;
248 Assoc_Node
: Node_Id
;
251 procedure Skip_Pragma_Semicolon
;
252 -- Skip past semicolon at end of pragma
254 ---------------------------
255 -- Skip_Pragma_Semicolon --
256 ---------------------------
258 procedure Skip_Pragma_Semicolon
is
260 if Token
/= Tok_Semicolon
then
262 -- If skipping the pragma, ignore a missing semicolon
267 -- Otherwise demand a semicolon
273 -- Scan past semicolon if present
278 end Skip_Pragma_Semicolon
;
280 -- Start of processing for P_Pragma
283 Prag_Node
:= New_Node
(N_Pragma
, Token_Ptr
);
285 Prag_Name
:= Token_Name
;
288 Style
.Check_Pragma_Name
;
291 -- Ada 2005 (AI-284): INTERFACE is a new reserved word but it is
292 -- allowed as a pragma name.
294 if Ada_Version
>= Ada_05
295 and then Token
= Tok_Interface
297 Prag_Name
:= Name_Interface
;
298 Ident_Node
:= Make_Identifier
(Token_Ptr
, Name_Interface
);
299 Scan
; -- past INTERFACE
301 Ident_Node
:= P_Identifier
;
304 Set_Pragma_Identifier
(Prag_Node
, Ident_Node
);
306 -- See if special INTERFACE/IMPORT check is required
308 if SIS_Entry_Active
then
309 Interface_Check_Required
:= (Prag_Name
= Name_Interface
);
310 Import_Check_Required
:= (Prag_Name
= Name_Import
);
312 Interface_Check_Required
:= False;
313 Import_Check_Required
:= False;
316 -- Scan arguments. We assume that arguments are present if there is
317 -- a left paren, or if a semicolon is missing and there is another
318 -- token on the same line as the pragma name.
320 if Token
= Tok_Left_Paren
321 or else (Token
/= Tok_Semicolon
322 and then not Token_Is_At_Start_Of_Line
)
324 Set_Pragma_Argument_Associations
(Prag_Node
, New_List
);
328 Arg_Count
:= Arg_Count
+ 1;
329 Scan_Pragma_Argument_Association
(Identifier_Seen
, Assoc_Node
);
332 and then (Interface_Check_Required
or else Import_Check_Required
)
334 -- Here is where we cancel the SIS active status if this pragma
335 -- supplies a body for the currently active subprogram spec.
337 if Nkind
(Expression
(Assoc_Node
)) in N_Direct_Name
338 and then Chars
(Expression
(Assoc_Node
)) = Chars
(SIS_Labl
)
340 SIS_Entry_Active
:= False;
344 Append
(Assoc_Node
, Pragma_Argument_Associations
(Prag_Node
));
345 exit when Token
/= Tok_Comma
;
349 -- If we have := for pragma Debug, it is worth special casing the
350 -- error message (it is easy to think of pragma Debug as taking a
351 -- statement, and an assignment statement is the most likely
352 -- candidate for this error)
354 if Token
= Tok_Colon_Equal
and then Prag_Name
= Name_Debug
then
355 Error_Msg_SC
("argument for pragma Debug must be procedure call");
358 -- Normal case, we expect a right paren here
365 Semicolon_Loc
:= Token_Ptr
;
367 -- Now we have two tasks left, we need to scan out the semicolon
368 -- following the pragma, and we have to call Par.Prag to process
369 -- the pragma. Normally we do them in this order, however, there
370 -- is one exception namely pragma Style_Checks where we like to
371 -- skip the semicolon after processing the pragma, since that way
372 -- the style checks for the scanning of the semicolon follow the
373 -- settings of the pragma.
375 -- You might think we could just unconditionally do things in
376 -- the opposite order, but there are other pragmas, notably the
377 -- case of pragma Source_File_Name, which assume the semicolon
378 -- is already scanned out.
380 if Prag_Name
= Name_Style_Checks
then
381 Result
:= Par
.Prag
(Prag_Node
, Semicolon_Loc
);
382 Skip_Pragma_Semicolon
;
385 Skip_Pragma_Semicolon
;
386 return Par
.Prag
(Prag_Node
, Semicolon_Loc
);
391 Resync_Past_Semicolon
;
396 -- This routine is called if a pragma is encountered in an inappropriate
397 -- position, the pragma is scanned out and control returns to continue.
399 -- The caller has checked that the initial token is pragma
401 -- Error recovery: cannot raise Error_Resync
403 procedure P_Pragmas_Misplaced
is
405 while Token
= Tok_Pragma
loop
406 Error_Msg_SC
("pragma not allowed here");
407 Discard_Junk_Node
(P_Pragma
(Skipping
=> True));
409 end P_Pragmas_Misplaced
;
411 -- This function is called to scan out an optional sequence of pragmas.
412 -- If no pragmas are found, then No_List is returned.
414 -- Error recovery: Cannot raise Error_Resync
416 function P_Pragmas_Opt
return List_Id
is
420 if Token
= Tok_Pragma
then
430 -- This procedure is called to scan out an optional sequence of pragmas.
431 -- Any pragmas found are appended to the list provided as an argument.
433 -- Error recovery: Cannot raise Error_Resync
435 procedure P_Pragmas_Opt
(List
: List_Id
) is
439 while Token
= Tok_Pragma
loop
442 if Nkind
(P
) /= N_Error
443 and then (Pragma_Name
(P
) = Name_Assert
445 Pragma_Name
(P
) = Name_Debug
)
447 Error_Msg_Name_1
:= Pragma_Name
(P
);
449 ("pragma% must be in declaration/statement context", P
);
456 --------------------------------------
457 -- 2.8 Pragma_Argument Association --
458 --------------------------------------
460 -- PRAGMA_ARGUMENT_ASSOCIATION ::=
461 -- [pragma_argument_IDENTIFIER =>] NAME
462 -- | [pragma_argument_IDENTIFIER =>] EXPRESSION
464 -- Error recovery: cannot raise Error_Resync
466 procedure Scan_Pragma_Argument_Association
467 (Identifier_Seen
: in out Boolean;
468 Association
: out Node_Id
)
470 Scan_State
: Saved_Scan_State
;
471 Identifier_Node
: Node_Id
;
472 Id_Present
: Boolean;
475 Association
:= New_Node
(N_Pragma_Argument_Association
, Token_Ptr
);
476 Set_Chars
(Association
, No_Name
);
478 -- Argument starts with identifier
480 if Token
= Tok_Identifier
then
481 Identifier_Node
:= Token_Node
;
482 Save_Scan_State
(Scan_State
); -- at Identifier
483 Scan
; -- past Identifier
485 if Token
= Tok_Arrow
then
486 Identifier_Seen
:= True;
488 Set_Chars
(Association
, Chars
(Identifier_Node
));
491 -- Case of argument with no identifier
494 Restore_Scan_State
(Scan_State
); -- to Identifier
498 -- Argument does not start with identifier
504 if Identifier_Seen
and not Id_Present
then
506 ("|pragma argument identifier required here (RM 2.8(4))");
510 Set_Expression
(Association
, P_Expression
);
512 Set_Expression
(Association
, P_Expression_If_OK
);
514 end Scan_Pragma_Argument_Association
;