1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, 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 -- Similarly, warn about Ada 2012 reserved words
81 if Ada_Version in Ada_95 .. Ada_2005
82 and then Warn_On_Ada_2012_Compatibility
84 if Token_Name = Name_Some then
85 Error_Msg_N ("& is a reserved word in Ada 2012?", Token_Node);
89 Ident_Node := Token_Node;
90 Scan; -- past Identifier
93 -- If we have a reserved identifier, manufacture an identifier with
94 -- a corresponding name after posting an appropriate error message
96 elsif Is_Reserved_Identifier (C) then
97 Scan_Reserved_Identifier (Force_Msg => False);
98 Ident_Node := Token_Node;
99 Scan; -- past the node
102 -- Otherwise we have junk that cannot be interpreted as an identifier
105 T_Identifier; -- to give message
110 --------------------------
111 -- 2.3 Letter Or Digit --
112 --------------------------
114 -- Parsed by P_Identifier (2.3)
116 --------------------------
117 -- 2.4 Numeric Literal --
118 --------------------------
120 -- NUMERIC_LITERAL ::= DECIMAL_LITERAL | BASED_LITERAL
122 -- Numeric literal is returned by the scanner as either
123 -- Tok_Integer_Literal or Tok_Real_Literal
125 ----------------------------
126 -- 2.4.1 Decimal Literal --
127 ----------------------------
129 -- DECIMAL_LITERAL ::= NUMERAL [.NUMERAL] [EXPONENT]
131 -- Handled by scanner as part of numeric literal handing (see 2.4)
137 -- NUMERAL ::= DIGIT {[UNDERLINE] DIGIT}
139 -- Handled by scanner as part of numeric literal handling (see 2.4)
141 ---------------------
143 ---------------------
145 -- EXPONENT ::= E [+] NUMERAL | E - NUMERAL
147 -- Handled by scanner as part of numeric literal handling (see 2.4)
149 --------------------------
150 -- 2.4.2 Based Literal --
151 --------------------------
154 -- BASE # BASED_NUMERAL [.BASED_NUMERAL] # [EXPONENT]
156 -- Handled by scanner as part of numeric literal handling (see 2.4)
164 -- Handled by scanner as part of numeric literal handling (see 2.4)
166 --------------------------
167 -- 2.4.2 Based Numeral --
168 --------------------------
171 -- EXTENDED_DIGIT {[UNDERLINE] EXTENDED_DIGIT}
173 -- Handled by scanner as part of numeric literal handling (see 2.4)
175 ---------------------------
176 -- 2.4.2 Extended Digit --
177 ---------------------------
179 -- EXTENDED_DIGIT ::= DIGIT | A | B | C | D | E | F
181 -- Handled by scanner as part of numeric literal handling (see 2.4)
183 ----------------------------
184 -- 2.5 Character Literal --
185 ----------------------------
187 -- CHARACTER_LITERAL ::= ' GRAPHIC_CHARACTER '
189 -- Handled by the scanner and returned as Tok_Char_Literal
191 -------------------------
192 -- 2.6 String Literal --
193 -------------------------
195 -- STRING LITERAL ::= "{STRING_ELEMENT}"
197 -- Handled by the scanner and returned as Tok_String_Literal
198 -- or if the string looks like an operator as Tok_Operator_Symbol.
200 -------------------------
201 -- 2.6 String Element --
202 -------------------------
204 -- STRING_ELEMENT ::= "" | non-quotation_mark_GRAPHIC_CHARACTER
206 -- A STRING_ELEMENT is either a pair of quotation marks ("),
207 -- or a single GRAPHIC_CHARACTER other than a quotation mark.
209 -- Handled by scanner as part of string literal handling (see 2.4)
215 -- A COMMENT starts with two adjacent hyphens and extends up to the
216 -- end of the line. A COMMENT may appear on any line of a program.
218 -- Handled by the scanner which simply skips past encountered comments
224 -- PRAGMA ::= pragma IDENTIFIER
225 -- [(PRAGMA_ARGUMENT_ASSOCIATION {, PRAGMA_ARGUMENT_ASSOCIATION})];
227 -- The caller has checked that the initial token is PRAGMA
229 -- Error recovery: cannot raise Error_Resync
231 -- One special piece of processing is needed in this routine. As described
232 -- in the section on "Handling semicolon used in place of IS" in module
233 -- Parse, the parser detects the case of missing subprogram bodies to
234 -- allow recovery from this syntactic error. Pragma INTERFACE (and, for
235 -- Ada 95, pragma IMPORT) can appear in place of the body. The parser must
236 -- recognize the use of these two pragmas in this context, otherwise it
237 -- will think there are missing bodies, and try to change ; to IS, when
238 -- in fact the bodies ARE present, supplied by these pragmas.
240 function P_Pragma (Skipping : Boolean := False) return Node_Id is
241 Interface_Check_Required : Boolean := False;
242 -- Set True if check of pragma INTERFACE is required
244 Import_Check_Required : Boolean := False;
245 -- Set True if check of pragma IMPORT is required
247 Arg_Count : Int := 0;
248 -- Number of argument associations processed
250 Identifier_Seen : Boolean := False;
251 -- Set True if an identifier is encountered for a pragma argument. Used
252 -- to check that there are no more arguments without identifiers.
256 Semicolon_Loc : Source_Ptr;
257 Ident_Node : Node_Id;
258 Assoc_Node : Node_Id;
261 procedure Skip_Pragma_Semicolon;
262 -- Skip past semicolon at end of pragma
264 ---------------------------
265 -- Skip_Pragma_Semicolon --
266 ---------------------------
268 procedure Skip_Pragma_Semicolon is
270 if Token /= Tok_Semicolon then
272 -- If skipping the pragma, ignore a missing semicolon
277 -- Otherwise demand a semicolon
283 -- Scan past semicolon if present
288 end Skip_Pragma_Semicolon;
290 -- Start of processing for P_Pragma
293 Prag_Node := New_Node (N_Pragma, Token_Ptr);
295 Prag_Name := Token_Name;
298 Style.Check_Pragma_Name;
301 -- Ada 2005 (AI-284): INTERFACE is a new reserved word but it is
302 -- allowed as a pragma name.
304 if Ada_Version >= Ada_2005
305 and then Token = Tok_Interface
307 Prag_Name := Name_Interface;
308 Ident_Node := Make_Identifier (Token_Ptr, Name_Interface);
309 Scan; -- past INTERFACE
311 Ident_Node := P_Identifier;
314 Set_Pragma_Identifier (Prag_Node, Ident_Node);
316 -- See if special INTERFACE/IMPORT check is required
318 if SIS_Entry_Active then
319 Interface_Check_Required := (Prag_Name = Name_Interface);
320 Import_Check_Required := (Prag_Name = Name_Import);
322 Interface_Check_Required := False;
323 Import_Check_Required := False;
326 -- Scan arguments. We assume that arguments are present if there is
327 -- a left paren, or if a semicolon is missing and there is another
328 -- token on the same line as the pragma name.
330 if Token = Tok_Left_Paren
331 or else (Token /= Tok_Semicolon
332 and then not Token_Is_At_Start_Of_Line)
334 Set_Pragma_Argument_Associations (Prag_Node, New_List);
338 Arg_Count := Arg_Count + 1;
339 Scan_Pragma_Argument_Association (Identifier_Seen, Assoc_Node);
342 and then (Interface_Check_Required or else Import_Check_Required)
344 -- Here is where we cancel the SIS active status if this pragma
345 -- supplies a body for the currently active subprogram spec.
347 if Nkind (Expression (Assoc_Node)) in N_Direct_Name
348 and then Chars (Expression (Assoc_Node)) = Chars (SIS_Labl)
350 SIS_Entry_Active := False;
354 Append (Assoc_Node, Pragma_Argument_Associations (Prag_Node));
355 exit when Token /= Tok_Comma;
359 -- If we have := for pragma Debug, it is worth special casing the
360 -- error message (it is easy to think of pragma Debug as taking a
361 -- statement, and an assignment statement is the most likely
362 -- candidate for this error)
364 if Token = Tok_Colon_Equal and then Prag_Name = Name_Debug then
365 Error_Msg_SC ("argument for pragma Debug must be procedure call");
368 -- Normal case, we expect a right paren here
375 Semicolon_Loc := Token_Ptr;
377 -- Now we have two tasks left, we need to scan out the semicolon
378 -- following the pragma, and we have to call Par.Prag to process
379 -- the pragma. Normally we do them in this order, however, there
380 -- is one exception namely pragma Style_Checks where we like to
381 -- skip the semicolon after processing the pragma, since that way
382 -- the style checks for the scanning of the semicolon follow the
383 -- settings of the pragma.
385 -- You might think we could just unconditionally do things in
386 -- the opposite order, but there are other pragmas, notably the
387 -- case of pragma Source_File_Name, which assume the semicolon
388 -- is already scanned out.
390 if Prag_Name = Name_Style_Checks then
391 Result := Par.Prag (Prag_Node, Semicolon_Loc);
392 Skip_Pragma_Semicolon;
395 Skip_Pragma_Semicolon;
396 return Par.Prag (Prag_Node, Semicolon_Loc);
401 Resync_Past_Semicolon;
406 -- This routine is called if a pragma is encountered in an inappropriate
407 -- position, the pragma is scanned out and control returns to continue.
409 -- The caller has checked that the initial token is pragma
411 -- Error recovery: cannot raise Error_Resync
413 procedure P_Pragmas_Misplaced is
415 while Token = Tok_Pragma loop
416 Error_Msg_SC ("pragma not allowed here");
417 Discard_Junk_Node (P_Pragma (Skipping => True));
419 end P_Pragmas_Misplaced;
421 -- This function is called to scan out an optional sequence of pragmas.
422 -- If no pragmas are found, then No_List is returned.
424 -- Error recovery: Cannot raise Error_Resync
426 function P_Pragmas_Opt return List_Id is
430 if Token = Tok_Pragma then
440 -- This procedure is called to scan out an optional sequence of pragmas.
441 -- Any pragmas found are appended to the list provided as an argument.
443 -- Error recovery: Cannot raise Error_Resync
445 procedure P_Pragmas_Opt (List : List_Id) is
449 while Token = Tok_Pragma loop
452 if Nkind (P) /= N_Error
453 and then (Pragma_Name (P) = Name_Assert
455 Pragma_Name (P) = Name_Debug)
457 Error_Msg_Name_1 := Pragma_Name (P);
459 ("pragma% must be in declaration/statement context", P);
466 --------------------------------------
467 -- 2.8 Pragma_Argument Association --
468 --------------------------------------
470 -- PRAGMA_ARGUMENT_ASSOCIATION ::=
471 -- [pragma_argument_IDENTIFIER =>] NAME
472 -- | [pragma_argument_IDENTIFIER =>] EXPRESSION
474 -- Error recovery: cannot raise Error_Resync
476 procedure Scan_Pragma_Argument_Association
477 (Identifier_Seen : in out Boolean;
478 Association : out Node_Id)
480 Scan_State : Saved_Scan_State;
481 Identifier_Node : Node_Id;
482 Id_Present : Boolean;
485 Association := New_Node (N_Pragma_Argument_Association, Token_Ptr);
486 Set_Chars (Association, No_Name);
488 -- Argument starts with identifier
490 if Token = Tok_Identifier then
491 Identifier_Node := Token_Node;
492 Save_Scan_State (Scan_State); -- at Identifier
493 Scan; -- past Identifier
495 if Token = Tok_Arrow then
496 Identifier_Seen := True;
498 Set_Chars (Association, Chars (Identifier_Node));
501 -- Case of argument with no identifier
504 Restore_Scan_State (Scan_State); -- to Identifier
508 -- Argument does not start with identifier
514 -- Diagnose error of "positional" argument for pragma appearing after
515 -- a "named" argument (quotes here are because that's not quite accurate
516 -- Ada RM terminology).
518 -- Since older GNAT versions did not generate this error, disable this
519 -- message in codepeer mode to help legacy code using codepeer.
521 if Identifier_Seen and not Id_Present and not CodePeer_Mode then
522 Error_Msg_SC ("|pragma argument identifier required here");
523 Error_Msg_SC ("\since previous argument had identifier (RM 2.8(4))");
527 Set_Expression (Association, P_Expression);
529 Set_Expression (Association, P_Expression_If_OK);
531 end Scan_Pragma_Argument_Association;