1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, 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
30 with Stringt; use Stringt;
35 -- Attributes that cannot have arguments
37 Is_Parameterless_Attribute : constant Attribute_Class_Array :=
38 (Attribute_Body_Version => True,
39 Attribute_External_Tag => True,
40 Attribute_Img => True,
41 Attribute_Version => True,
42 Attribute_Base => True,
43 Attribute_Class => True,
44 Attribute_Stub_Type => True,
45 Attribute_Type_Key => True,
47 -- This map contains True for parameterless attributes that return a
48 -- string or a type. For those attributes, a left parenthesis after
49 -- the attribute should not be analyzed as the beginning of a parameters
50 -- list because it may denote a slice operation (X'Img (1 .. 2)) or
51 -- a type conversion (X'Class (Y)).
53 -- Note that this map designates the minimum set of attributes where a
54 -- construct in parentheses that is not an argument can appear right
55 -- after the attribute. For attributes like 'Size, we do not put them
56 -- in the map. If someone writes X'Size (3), that's illegal in any case,
57 -- but we get a better error message by parsing the (3) as an illegal
58 -- argument to the attribute, rather than some meaningless junk that
59 -- follows the attribute.
61 -----------------------
62 -- Local Subprograms --
63 -----------------------
65 function P_Aggregate_Or_Paren_Expr return Node_Id;
66 function P_Allocator return Node_Id;
67 function P_Case_Expression_Alternative return Node_Id;
68 function P_Record_Or_Array_Component_Association return Node_Id;
69 function P_Factor return Node_Id;
70 function P_Primary return Node_Id;
71 function P_Relation return Node_Id;
72 function P_Term return Node_Id;
74 function P_Binary_Adding_Operator return Node_Kind;
75 function P_Logical_Operator return Node_Kind;
76 function P_Multiplying_Operator return Node_Kind;
77 function P_Relational_Operator return Node_Kind;
78 function P_Unary_Adding_Operator return Node_Kind;
80 procedure Bad_Range_Attribute (Loc : Source_Ptr);
81 -- Called to place complaint about bad range attribute at the given
82 -- source location. Terminates by raising Error_Resync.
84 procedure P_Membership_Test (N : Node_Id);
85 -- N is the node for a N_In or N_Not_In node whose right operand has not
86 -- yet been processed. It is called just after scanning out the IN keyword.
87 -- On return, either Right_Opnd or Alternatives is set, as appropriate.
89 function P_Range_Attribute_Reference (Prefix_Node : Node_Id) return Node_Id;
90 -- Scan a range attribute reference. The caller has scanned out the
91 -- prefix. The current token is known to be an apostrophe and the
92 -- following token is known to be RANGE.
94 -------------------------
95 -- Bad_Range_Attribute --
96 -------------------------
98 procedure Bad_Range_Attribute (Loc : Source_Ptr) is
100 Error_Msg ("range attribute cannot be used in expression!", Loc);
102 end Bad_Range_Attribute;
104 --------------------------
105 -- 4.1 Name (also 6.4) --
106 --------------------------
109 -- DIRECT_NAME | EXPLICIT_DEREFERENCE
110 -- | INDEXED_COMPONENT | SLICE
111 -- | SELECTED_COMPONENT | ATTRIBUTE
112 -- | TYPE_CONVERSION | FUNCTION_CALL
113 -- | CHARACTER_LITERAL
115 -- DIRECT_NAME ::= IDENTIFIER | OPERATOR_SYMBOL
117 -- PREFIX ::= NAME | IMPLICIT_DEREFERENCE
119 -- EXPLICIT_DEREFERENCE ::= NAME . all
121 -- IMPLICIT_DEREFERENCE ::= NAME
123 -- INDEXED_COMPONENT ::= PREFIX (EXPRESSION {, EXPRESSION})
125 -- SLICE ::= PREFIX (DISCRETE_RANGE)
127 -- SELECTED_COMPONENT ::= PREFIX . SELECTOR_NAME
129 -- SELECTOR_NAME ::= IDENTIFIER | CHARACTER_LITERAL | OPERATOR_SYMBOL
131 -- ATTRIBUTE_REFERENCE ::= PREFIX ' ATTRIBUTE_DESIGNATOR
133 -- ATTRIBUTE_DESIGNATOR ::=
134 -- IDENTIFIER [(static_EXPRESSION)]
135 -- | access | delta | digits
139 -- | function_PREFIX ACTUAL_PARAMETER_PART
141 -- ACTUAL_PARAMETER_PART ::=
142 -- (PARAMETER_ASSOCIATION {,PARAMETER_ASSOCIATION})
144 -- PARAMETER_ASSOCIATION ::=
145 -- [formal_parameter_SELECTOR_NAME =>] EXPLICIT_ACTUAL_PARAMETER
147 -- EXPLICIT_ACTUAL_PARAMETER ::= EXPRESSION | variable_NAME
149 -- Note: syntactically a procedure call looks just like a function call,
150 -- so this routine is in practice used to scan out procedure calls as well.
152 -- On return, Expr_Form is set to either EF_Name or EF_Simple_Name
154 -- Error recovery: can raise Error_Resync
156 -- Note: if on return Token = Tok_Apostrophe, then the apostrophe must be
157 -- followed by either a left paren (qualified expression case), or by
158 -- range (range attribute case). All other uses of apostrophe (i.e. all
159 -- other attributes) are handled in this routine.
161 -- Error recovery: can raise Error_Resync
163 function P_Name return Node_Id is
164 Scan_State : Saved_Scan_State;
166 Prefix_Node : Node_Id;
167 Ident_Node : Node_Id;
169 Range_Node : Node_Id;
172 Arg_List : List_Id := No_List; -- kill junk warning
173 Attr_Name : Name_Id := No_Name; -- kill junk warning
176 -- Case of not a name
178 if Token not in Token_Class_Name then
180 -- If it looks like start of expression, complain and scan expression
182 if Token in Token_Class_Literal
183 or else Token = Tok_Left_Paren
185 Error_Msg_SC ("name expected");
188 -- Otherwise some other junk, not much we can do
191 Error_Msg_AP ("name expected");
196 -- Loop through designators in qualified name
198 Name_Node := Token_Node;
201 Scan; -- past designator
202 exit when Token /= Tok_Dot;
203 Save_Scan_State (Scan_State); -- at dot
206 -- If we do not have another designator after the dot, then join
207 -- the normal circuit to handle a dot extension (may be .all or
208 -- character literal case). Otherwise loop back to scan the next
211 if Token not in Token_Class_Desig then
212 goto Scan_Name_Extension_Dot;
214 Prefix_Node := Name_Node;
215 Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
216 Set_Prefix (Name_Node, Prefix_Node);
217 Set_Selector_Name (Name_Node, Token_Node);
221 -- We have now scanned out a qualified designator. If the last token is
222 -- an operator symbol, then we certainly do not have the Snam case, so
223 -- we can just use the normal name extension check circuit
225 if Prev_Token = Tok_Operator_Symbol then
226 goto Scan_Name_Extension;
229 -- We have scanned out a qualified simple name, check for name extension
230 -- Note that we know there is no dot here at this stage, so the only
231 -- possible cases of name extension are apostrophe and left paren.
233 if Token = Tok_Apostrophe then
234 Save_Scan_State (Scan_State); -- at apostrophe
235 Scan; -- past apostrophe
237 -- Qualified expression in Ada 2012 mode (treated as a name)
239 if Ada_Version >= Ada_2012 and then Token = Tok_Left_Paren then
240 goto Scan_Name_Extension_Apostrophe;
242 -- If left paren not in Ada 2012, then it is not part of the name,
243 -- since qualified expressions are not names in prior versions of
244 -- Ada, so return with Token backed up to point to the apostrophe.
245 -- The treatment for the range attribute is similar (we do not
246 -- consider x'range to be a name in this grammar).
248 elsif Token = Tok_Left_Paren or else Token = Tok_Range then
249 Restore_Scan_State (Scan_State); -- to apostrophe
250 Expr_Form := EF_Simple_Name;
253 -- Otherwise we have the case of a name extended by an attribute
256 goto Scan_Name_Extension_Apostrophe;
259 -- Check case of qualified simple name extended by a left parenthesis
261 elsif Token = Tok_Left_Paren then
262 Scan; -- past left paren
263 goto Scan_Name_Extension_Left_Paren;
265 -- Otherwise the qualified simple name is not extended, so return
268 Expr_Form := EF_Simple_Name;
272 -- Loop scanning past name extensions. A label is used for control
273 -- transfer for this loop for ease of interfacing with the finite state
274 -- machine in the parenthesis scanning circuit, and also to allow for
275 -- passing in control to the appropriate point from the above code.
277 <<Scan_Name_Extension>>
279 -- Character literal used as name cannot be extended. Also this
280 -- cannot be a call, since the name for a call must be a designator.
281 -- Return in these cases, or if there is no name extension
283 if Token not in Token_Class_Namext
284 or else Prev_Token = Tok_Char_Literal
286 Expr_Form := EF_Name;
290 -- Merge here when we know there is a name extension
292 <<Scan_Name_Extension_OK>>
294 if Token = Tok_Left_Paren then
295 Scan; -- past left paren
296 goto Scan_Name_Extension_Left_Paren;
298 elsif Token = Tok_Apostrophe then
299 Save_Scan_State (Scan_State); -- at apostrophe
300 Scan; -- past apostrophe
301 goto Scan_Name_Extension_Apostrophe;
303 else -- Token = Tok_Dot
304 Save_Scan_State (Scan_State); -- at dot
306 goto Scan_Name_Extension_Dot;
309 -- Case of name extended by dot (selection), dot is already skipped
310 -- and the scan state at the point of the dot is saved in Scan_State.
312 <<Scan_Name_Extension_Dot>>
314 -- Explicit dereference case
316 if Token = Tok_All then
317 Prefix_Node := Name_Node;
318 Name_Node := New_Node (N_Explicit_Dereference, Token_Ptr);
319 Set_Prefix (Name_Node, Prefix_Node);
321 goto Scan_Name_Extension;
323 -- Selected component case
325 elsif Token in Token_Class_Name then
326 Prefix_Node := Name_Node;
327 Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
328 Set_Prefix (Name_Node, Prefix_Node);
329 Set_Selector_Name (Name_Node, Token_Node);
330 Scan; -- past selector
331 goto Scan_Name_Extension;
333 -- Reserved identifier as selector
335 elsif Is_Reserved_Identifier then
336 Scan_Reserved_Identifier (Force_Msg => False);
337 Prefix_Node := Name_Node;
338 Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
339 Set_Prefix (Name_Node, Prefix_Node);
340 Set_Selector_Name (Name_Node, Token_Node);
341 Scan; -- past identifier used as selector
342 goto Scan_Name_Extension;
344 -- If dot is at end of line and followed by nothing legal,
345 -- then assume end of name and quit (dot will be taken as
346 -- an erroneous form of some other punctuation by our caller).
348 elsif Token_Is_At_Start_Of_Line then
349 Restore_Scan_State (Scan_State);
352 -- Here if nothing legal after the dot
355 Error_Msg_AP ("selector expected");
359 -- Here for an apostrophe as name extension. The scan position at the
360 -- apostrophe has already been saved, and the apostrophe scanned out.
362 <<Scan_Name_Extension_Apostrophe>>
364 Scan_Apostrophe : declare
365 function Apostrophe_Should_Be_Semicolon return Boolean;
366 -- Checks for case where apostrophe should probably be
367 -- a semicolon, and if so, gives appropriate message,
368 -- resets the scan pointer to the apostrophe, changes
369 -- the current token to Tok_Semicolon, and returns True.
370 -- Otherwise returns False.
372 ------------------------------------
373 -- Apostrophe_Should_Be_Semicolon --
374 ------------------------------------
376 function Apostrophe_Should_Be_Semicolon return Boolean is
378 if Token_Is_At_Start_Of_Line then
379 Restore_Scan_State (Scan_State); -- to apostrophe
380 Error_Msg_SC ("|""''"" should be "";""");
381 Token := Tok_Semicolon;
386 end Apostrophe_Should_Be_Semicolon;
388 -- Start of processing for Scan_Apostrophe
391 -- Check for qualified expression case in Ada 2012 mode
393 if Ada_Version >= Ada_2012 and then Token = Tok_Left_Paren then
394 Name_Node := P_Qualified_Expression (Name_Node);
395 goto Scan_Name_Extension;
397 -- If range attribute after apostrophe, then return with Token
398 -- pointing to the apostrophe. Note that in this case the prefix
399 -- need not be a simple name (cases like A.all'range). Similarly
400 -- if there is a left paren after the apostrophe, then we also
401 -- return with Token pointing to the apostrophe (this is the
402 -- aggregate case, or some error case).
404 elsif Token = Tok_Range or else Token = Tok_Left_Paren then
405 Restore_Scan_State (Scan_State); -- to apostrophe
406 Expr_Form := EF_Name;
409 -- Here for cases where attribute designator is an identifier
411 elsif Token = Tok_Identifier then
412 Attr_Name := Token_Name;
414 if not Is_Attribute_Name (Attr_Name) then
415 if Apostrophe_Should_Be_Semicolon then
416 Expr_Form := EF_Name;
419 -- Here for a bad attribute name
422 Signal_Bad_Attribute;
423 Scan; -- past bad identifier
425 if Token = Tok_Left_Paren then
426 Scan; -- past left paren
429 Discard_Junk_Node (P_Expression_If_OK);
430 exit when not Comma_Present;
441 Style.Check_Attribute_Name (False);
444 -- Here for case of attribute designator is not an identifier
447 if Token = Tok_Delta then
448 Attr_Name := Name_Delta;
450 elsif Token = Tok_Digits then
451 Attr_Name := Name_Digits;
453 elsif Token = Tok_Access then
454 Attr_Name := Name_Access;
456 elsif Token = Tok_Mod and then Ada_Version >= Ada_95 then
457 Attr_Name := Name_Mod;
459 elsif Apostrophe_Should_Be_Semicolon then
460 Expr_Form := EF_Name;
464 Error_Msg_AP ("attribute designator expected");
469 Style.Check_Attribute_Name (True);
473 -- We come here with an OK attribute scanned, and the
474 -- corresponding Attribute identifier node stored in Ident_Node.
476 Prefix_Node := Name_Node;
477 Name_Node := New_Node (N_Attribute_Reference, Prev_Token_Ptr);
478 Scan; -- past attribute designator
479 Set_Prefix (Name_Node, Prefix_Node);
480 Set_Attribute_Name (Name_Node, Attr_Name);
482 -- Scan attribute arguments/designator. We skip this if we know
483 -- that the attribute cannot have an argument.
485 if Token = Tok_Left_Paren
487 Is_Parameterless_Attribute (Get_Attribute_Id (Attr_Name))
489 Set_Expressions (Name_Node, New_List);
490 Scan; -- past left paren
494 Expr : constant Node_Id := P_Expression_If_OK;
497 if Token = Tok_Arrow then
499 ("named parameters not permitted for attributes");
500 Scan; -- past junk arrow
503 Append (Expr, Expressions (Name_Node));
504 exit when not Comma_Present;
512 goto Scan_Name_Extension;
515 -- Here for left parenthesis extending name (left paren skipped)
517 <<Scan_Name_Extension_Left_Paren>>
519 -- We now have to scan through a list of items, terminated by a
520 -- right parenthesis. The scan is handled by a finite state
521 -- machine. The possibilities are:
525 -- This is a slice. This case is handled in LP_State_Init
527 -- (expression, expression, ..)
529 -- This is interpreted as an indexed component, i.e. as a
530 -- case of a name which can be extended in the normal manner.
531 -- This case is handled by LP_State_Name or LP_State_Expr.
533 -- Note: conditional expressions (without an extra level of
534 -- parentheses) are permitted in this context).
536 -- (..., identifier => expression , ...)
538 -- If there is at least one occurrence of identifier => (but
539 -- none of the other cases apply), then we have a call.
541 -- Test for Id => case
543 if Token = Tok_Identifier then
544 Save_Scan_State (Scan_State); -- at Id
547 -- Test for => (allow := as an error substitute)
549 if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
550 Restore_Scan_State (Scan_State); -- to Id
551 Arg_List := New_List;
555 Restore_Scan_State (Scan_State); -- to Id
559 -- Here we have an expression after all
561 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
563 -- Check cases of discrete range for a slice
565 -- First possibility: Range_Attribute_Reference
567 if Expr_Form = EF_Range_Attr then
568 Range_Node := Expr_Node;
570 -- Second possibility: Simple_expression .. Simple_expression
572 elsif Token = Tok_Dot_Dot then
573 Check_Simple_Expression (Expr_Node);
574 Range_Node := New_Node (N_Range, Token_Ptr);
575 Set_Low_Bound (Range_Node, Expr_Node);
577 Expr_Node := P_Expression;
578 Check_Simple_Expression (Expr_Node);
579 Set_High_Bound (Range_Node, Expr_Node);
581 -- Third possibility: Type_name range Range
583 elsif Token = Tok_Range then
584 if Expr_Form /= EF_Simple_Name then
585 Error_Msg_SC ("subtype mark must precede RANGE");
589 Range_Node := P_Subtype_Indication (Expr_Node);
591 -- Otherwise we just have an expression. It is true that we might
592 -- have a subtype mark without a range constraint but this case
593 -- is syntactically indistinguishable from the expression case.
596 Arg_List := New_List;
600 -- Fall through here with unmistakable Discrete range scanned,
601 -- which means that we definitely have the case of a slice. The
602 -- Discrete range is in Range_Node.
604 if Token = Tok_Comma then
605 Error_Msg_SC ("slice cannot have more than one dimension");
608 elsif Token /= Tok_Right_Paren then
613 Scan; -- past right paren
614 Prefix_Node := Name_Node;
615 Name_Node := New_Node (N_Slice, Sloc (Prefix_Node));
616 Set_Prefix (Name_Node, Prefix_Node);
617 Set_Discrete_Range (Name_Node, Range_Node);
619 -- An operator node is legal as a prefix to other names,
620 -- but not for a slice.
622 if Nkind (Prefix_Node) = N_Operator_Symbol then
623 Error_Msg_N ("illegal prefix for slice", Prefix_Node);
626 -- If we have a name extension, go scan it
628 if Token in Token_Class_Namext then
629 goto Scan_Name_Extension_OK;
631 -- Otherwise return (a slice is a name, but is not a call)
634 Expr_Form := EF_Name;
639 -- In LP_State_Expr, we have scanned one or more expressions, and
640 -- so we have a call or an indexed component which is a name. On
641 -- entry we have the expression just scanned in Expr_Node and
642 -- Arg_List contains the list of expressions encountered so far
645 Append (Expr_Node, Arg_List);
647 if Token = Tok_Arrow then
649 ("expect identifier in parameter association",
653 elsif not Comma_Present then
655 Prefix_Node := Name_Node;
656 Name_Node := New_Node (N_Indexed_Component, Sloc (Prefix_Node));
657 Set_Prefix (Name_Node, Prefix_Node);
658 Set_Expressions (Name_Node, Arg_List);
659 goto Scan_Name_Extension;
662 -- Comma present (and scanned out), test for identifier => case
663 -- Test for identifier => case
665 if Token = Tok_Identifier then
666 Save_Scan_State (Scan_State); -- at Id
669 -- Test for => (allow := as error substitute)
671 if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
672 Restore_Scan_State (Scan_State); -- to Id
675 -- Otherwise it's just an expression after all, so backup
678 Restore_Scan_State (Scan_State); -- to Id
682 -- Here we have an expression after all, so stay in this state
684 Expr_Node := P_Expression_If_OK;
687 -- LP_State_Call corresponds to the situation in which at least
688 -- one instance of Id => Expression has been encountered, so we
689 -- know that we do not have a name, but rather a call. We enter
690 -- it with the scan pointer pointing to the next argument to scan,
691 -- and Arg_List containing the list of arguments scanned so far.
695 -- Test for case of Id => Expression (named parameter)
697 if Token = Tok_Identifier then
698 Save_Scan_State (Scan_State); -- at Id
699 Ident_Node := Token_Node;
702 -- Deal with => (allow := as erroneous substitute)
704 if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
705 Arg_Node := New_Node (N_Parameter_Association, Prev_Token_Ptr);
706 Set_Selector_Name (Arg_Node, Ident_Node);
708 Set_Explicit_Actual_Parameter (Arg_Node, P_Expression);
709 Append (Arg_Node, Arg_List);
711 -- If a comma follows, go back and scan next entry
713 if Comma_Present then
716 -- Otherwise we have the end of a call
719 Prefix_Node := Name_Node;
720 Name_Node := New_Node (N_Function_Call, Sloc (Prefix_Node));
721 Set_Name (Name_Node, Prefix_Node);
722 Set_Parameter_Associations (Name_Node, Arg_List);
725 if Token in Token_Class_Namext then
726 goto Scan_Name_Extension_OK;
728 -- This is a case of a call which cannot be a name
731 Expr_Form := EF_Name;
736 -- Not named parameter: Id started an expression after all
739 Restore_Scan_State (Scan_State); -- to Id
743 -- Here if entry did not start with Id => which means that it
744 -- is a positional parameter, which is not allowed, since we
745 -- have seen at least one named parameter already.
748 ("positional parameter association " &
749 "not allowed after named one");
751 Expr_Node := P_Expression_If_OK;
753 -- Leaving the '>' in an association is not unusual, so suggest
756 if Nkind (Expr_Node) = N_Op_Eq then
757 Error_Msg_N ("\maybe `='>` was intended", Expr_Node);
760 -- We go back to scanning out expressions, so that we do not get
761 -- multiple error messages when several positional parameters
762 -- follow a named parameter.
766 -- End of treatment for name extensions starting with left paren
768 -- End of loop through name extensions
772 -- This function parses a restricted form of Names which are either
773 -- designators, or designators preceded by a sequence of prefixes
774 -- that are direct names.
776 -- Error recovery: cannot raise Error_Resync
778 function P_Function_Name return Node_Id is
779 Designator_Node : Node_Id;
780 Prefix_Node : Node_Id;
781 Selector_Node : Node_Id;
782 Dot_Sloc : Source_Ptr := No_Location;
785 -- Prefix_Node is set to the gathered prefix so far, Empty means that
786 -- no prefix has been scanned. This allows us to build up the result
787 -- in the required right recursive manner.
789 Prefix_Node := Empty;
791 -- Loop through prefixes
794 Designator_Node := Token_Node;
796 if Token not in Token_Class_Desig then
797 return P_Identifier; -- let P_Identifier issue the error message
799 else -- Token in Token_Class_Desig
800 Scan; -- past designator
801 exit when Token /= Tok_Dot;
804 -- Here at a dot, with token just before it in Designator_Node
806 if No (Prefix_Node) then
807 Prefix_Node := Designator_Node;
809 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
810 Set_Prefix (Selector_Node, Prefix_Node);
811 Set_Selector_Name (Selector_Node, Designator_Node);
812 Prefix_Node := Selector_Node;
815 Dot_Sloc := Token_Ptr;
819 -- Fall out of the loop having just scanned a designator
821 if No (Prefix_Node) then
822 return Designator_Node;
824 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
825 Set_Prefix (Selector_Node, Prefix_Node);
826 Set_Selector_Name (Selector_Node, Designator_Node);
827 return Selector_Node;
835 -- This function parses a restricted form of Names which are either
836 -- identifiers, or identifiers preceded by a sequence of prefixes
837 -- that are direct names.
839 -- Error recovery: cannot raise Error_Resync
841 function P_Qualified_Simple_Name return Node_Id is
842 Designator_Node : Node_Id;
843 Prefix_Node : Node_Id;
844 Selector_Node : Node_Id;
845 Dot_Sloc : Source_Ptr := No_Location;
848 -- Prefix node is set to the gathered prefix so far, Empty means that
849 -- no prefix has been scanned. This allows us to build up the result
850 -- in the required right recursive manner.
852 Prefix_Node := Empty;
854 -- Loop through prefixes
857 Designator_Node := Token_Node;
859 if Token = Tok_Identifier then
860 Scan; -- past identifier
861 exit when Token /= Tok_Dot;
863 elsif Token not in Token_Class_Desig then
864 return P_Identifier; -- let P_Identifier issue the error message
867 Scan; -- past designator
869 if Token /= Tok_Dot then
870 Error_Msg_SP ("identifier expected");
875 -- Here at a dot, with token just before it in Designator_Node
877 if No (Prefix_Node) then
878 Prefix_Node := Designator_Node;
880 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
881 Set_Prefix (Selector_Node, Prefix_Node);
882 Set_Selector_Name (Selector_Node, Designator_Node);
883 Prefix_Node := Selector_Node;
886 Dot_Sloc := Token_Ptr;
890 -- Fall out of the loop having just scanned an identifier
892 if No (Prefix_Node) then
893 return Designator_Node;
895 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
896 Set_Prefix (Selector_Node, Prefix_Node);
897 Set_Selector_Name (Selector_Node, Designator_Node);
898 return Selector_Node;
904 end P_Qualified_Simple_Name;
906 -- This procedure differs from P_Qualified_Simple_Name only in that it
907 -- raises Error_Resync if any error is encountered. It only returns after
908 -- scanning a valid qualified simple name.
910 -- Error recovery: can raise Error_Resync
912 function P_Qualified_Simple_Name_Resync return Node_Id is
913 Designator_Node : Node_Id;
914 Prefix_Node : Node_Id;
915 Selector_Node : Node_Id;
916 Dot_Sloc : Source_Ptr := No_Location;
919 Prefix_Node := Empty;
921 -- Loop through prefixes
924 Designator_Node := Token_Node;
926 if Token = Tok_Identifier then
927 Scan; -- past identifier
928 exit when Token /= Tok_Dot;
930 elsif Token not in Token_Class_Desig then
931 Discard_Junk_Node (P_Identifier); -- to issue the error message
935 Scan; -- past designator
937 if Token /= Tok_Dot then
938 Error_Msg_SP ("identifier expected");
943 -- Here at a dot, with token just before it in Designator_Node
945 if No (Prefix_Node) then
946 Prefix_Node := Designator_Node;
948 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
949 Set_Prefix (Selector_Node, Prefix_Node);
950 Set_Selector_Name (Selector_Node, Designator_Node);
951 Prefix_Node := Selector_Node;
954 Dot_Sloc := Token_Ptr;
958 -- Fall out of the loop having just scanned an identifier
960 if No (Prefix_Node) then
961 return Designator_Node;
963 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
964 Set_Prefix (Selector_Node, Prefix_Node);
965 Set_Selector_Name (Selector_Node, Designator_Node);
966 return Selector_Node;
968 end P_Qualified_Simple_Name_Resync;
970 ----------------------
971 -- 4.1 Direct_Name --
972 ----------------------
974 -- Parsed by P_Name and other functions in section 4.1
980 -- Parsed by P_Name (4.1)
982 -------------------------------
983 -- 4.1 Explicit Dereference --
984 -------------------------------
986 -- Parsed by P_Name (4.1)
988 -------------------------------
989 -- 4.1 Implicit_Dereference --
990 -------------------------------
992 -- Parsed by P_Name (4.1)
994 ----------------------------
995 -- 4.1 Indexed Component --
996 ----------------------------
998 -- Parsed by P_Name (4.1)
1004 -- Parsed by P_Name (4.1)
1006 -----------------------------
1007 -- 4.1 Selected_Component --
1008 -----------------------------
1010 -- Parsed by P_Name (4.1)
1012 ------------------------
1013 -- 4.1 Selector Name --
1014 ------------------------
1016 -- Parsed by P_Name (4.1)
1018 ------------------------------
1019 -- 4.1 Attribute Reference --
1020 ------------------------------
1022 -- Parsed by P_Name (4.1)
1024 -------------------------------
1025 -- 4.1 Attribute Designator --
1026 -------------------------------
1028 -- Parsed by P_Name (4.1)
1030 --------------------------------------
1031 -- 4.1.4 Range Attribute Reference --
1032 --------------------------------------
1034 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
1036 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
1038 -- In the grammar, a RANGE attribute is simply a name, but its use is
1039 -- highly restricted, so in the parser, we do not regard it as a name.
1040 -- Instead, P_Name returns without scanning the 'RANGE part of the
1041 -- attribute, and the caller uses the following function to construct
1042 -- a range attribute in places where it is appropriate.
1044 -- Note that RANGE here is treated essentially as an identifier,
1045 -- rather than a reserved word.
1047 -- The caller has parsed the prefix, i.e. a name, and Token points to
1048 -- the apostrophe. The token after the apostrophe is known to be RANGE
1049 -- at this point. The prefix node becomes the prefix of the attribute.
1051 -- Error_Recovery: Cannot raise Error_Resync
1053 function P_Range_Attribute_Reference
1054 (Prefix_Node : Node_Id)
1057 Attr_Node : Node_Id;
1060 Attr_Node := New_Node (N_Attribute_Reference, Token_Ptr);
1061 Set_Prefix (Attr_Node, Prefix_Node);
1062 Scan; -- past apostrophe
1065 Style.Check_Attribute_Name (True);
1068 Set_Attribute_Name (Attr_Node, Name_Range);
1071 if Token = Tok_Left_Paren then
1072 Scan; -- past left paren
1073 Set_Expressions (Attr_Node, New_List (P_Expression_If_OK));
1078 end P_Range_Attribute_Reference;
1080 ---------------------------------------
1081 -- 4.1.4 Range Attribute Designator --
1082 ---------------------------------------
1084 -- Parsed by P_Range_Attribute_Reference (4.4)
1086 --------------------
1088 --------------------
1090 -- AGGREGATE ::= RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
1092 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3), except in the case where
1093 -- an aggregate is known to be required (code statement, extension
1094 -- aggregate), in which cases this routine performs the necessary check
1095 -- that we have an aggregate rather than a parenthesized expression
1097 -- Error recovery: can raise Error_Resync
1099 function P_Aggregate return Node_Id is
1100 Aggr_Sloc : constant Source_Ptr := Token_Ptr;
1101 Aggr_Node : constant Node_Id := P_Aggregate_Or_Paren_Expr;
1104 if Nkind (Aggr_Node) /= N_Aggregate
1106 Nkind (Aggr_Node) /= N_Extension_Aggregate
1109 ("aggregate may not have single positional component", Aggr_Sloc);
1116 ------------------------------------------------
1117 -- 4.3 Aggregate or Parenthesized Expression --
1118 ------------------------------------------------
1120 -- This procedure parses out either an aggregate or a parenthesized
1121 -- expression (these two constructs are closely related, since a
1122 -- parenthesized expression looks like an aggregate with a single
1123 -- positional component).
1126 -- RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
1128 -- RECORD_AGGREGATE ::= (RECORD_COMPONENT_ASSOCIATION_LIST)
1130 -- RECORD_COMPONENT_ASSOCIATION_LIST ::=
1131 -- RECORD_COMPONENT_ASSOCIATION {, RECORD_COMPONENT_ASSOCIATION}
1134 -- RECORD_COMPONENT_ASSOCIATION ::=
1135 -- [COMPONENT_CHOICE_LIST =>] EXPRESSION
1137 -- COMPONENT_CHOICE_LIST ::=
1138 -- component_SELECTOR_NAME {| component_SELECTOR_NAME}
1141 -- EXTENSION_AGGREGATE ::=
1142 -- (ANCESTOR_PART with RECORD_COMPONENT_ASSOCIATION_LIST)
1144 -- ANCESTOR_PART ::= EXPRESSION | SUBTYPE_MARK
1146 -- ARRAY_AGGREGATE ::=
1147 -- POSITIONAL_ARRAY_AGGREGATE | NAMED_ARRAY_AGGREGATE
1149 -- POSITIONAL_ARRAY_AGGREGATE ::=
1150 -- (EXPRESSION, EXPRESSION {, EXPRESSION})
1151 -- | (EXPRESSION {, EXPRESSION}, others => EXPRESSION)
1152 -- | (EXPRESSION {, EXPRESSION}, others => <>)
1154 -- NAMED_ARRAY_AGGREGATE ::=
1155 -- (ARRAY_COMPONENT_ASSOCIATION {, ARRAY_COMPONENT_ASSOCIATION})
1157 -- PRIMARY ::= (EXPRESSION);
1159 -- Error recovery: can raise Error_Resync
1161 -- Note: POSITIONAL_ARRAY_AGGREGATE rule has been extended to give support
1162 -- to Ada 2005 limited aggregates (AI-287)
1164 function P_Aggregate_Or_Paren_Expr return Node_Id is
1165 Aggregate_Node : Node_Id;
1166 Expr_List : List_Id;
1167 Assoc_List : List_Id;
1168 Expr_Node : Node_Id;
1169 Lparen_Sloc : Source_Ptr;
1170 Scan_State : Saved_Scan_State;
1172 procedure Box_Error;
1173 -- Called if <> is encountered as positional aggregate element. Issues
1174 -- error message and sets Expr_Node to Error.
1180 procedure Box_Error is
1182 if Ada_Version < Ada_2005 then
1183 Error_Msg_SC ("box in aggregate is an Ada 2005 extension");
1186 -- Ada 2005 (AI-287): The box notation is allowed only with named
1187 -- notation because positional notation might be error prone. For
1188 -- example, in "(X, <>, Y, <>)", there is no type associated with
1189 -- the boxes, so you might not be leaving out the components you
1190 -- thought you were leaving out.
1192 Error_Msg_SC ("(Ada 2005) box only allowed with named notation");
1197 -- Start of processsing for P_Aggregate_Or_Paren_Expr
1200 Lparen_Sloc := Token_Ptr;
1203 -- Conditional expression case
1205 if Token = Tok_If then
1206 Expr_Node := P_Conditional_Expression;
1210 -- Case expression case
1212 elsif Token = Tok_Case then
1213 Expr_Node := P_Case_Expression;
1217 -- Note: the mechanism used here of rescanning the initial expression
1218 -- is distinctly unpleasant, but it saves a lot of fiddling in scanning
1219 -- out the discrete choice list.
1221 -- Deal with expression and extension aggregate cases first
1223 elsif Token /= Tok_Others then
1224 Save_Scan_State (Scan_State); -- at start of expression
1226 -- Deal with (NULL RECORD) case
1228 if Token = Tok_Null then
1231 if Token = Tok_Record then
1232 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1233 Set_Null_Record_Present (Aggregate_Node, True);
1234 Scan; -- past RECORD
1236 return Aggregate_Node;
1238 Restore_Scan_State (Scan_State); -- to NULL that must be expr
1242 -- Scan expression, handling box appearing as positional argument
1244 if Token = Tok_Box then
1247 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
1250 -- Extension aggregate case
1252 if Token = Tok_With then
1253 if Nkind (Expr_Node) = N_Attribute_Reference
1254 and then Attribute_Name (Expr_Node) = Name_Range
1256 Bad_Range_Attribute (Sloc (Expr_Node));
1260 if Ada_Version = Ada_83 then
1261 Error_Msg_SC ("(Ada 83) extension aggregate not allowed");
1264 Aggregate_Node := New_Node (N_Extension_Aggregate, Lparen_Sloc);
1265 Set_Ancestor_Part (Aggregate_Node, Expr_Node);
1268 -- Deal with WITH NULL RECORD case
1270 if Token = Tok_Null then
1271 Save_Scan_State (Scan_State); -- at NULL
1274 if Token = Tok_Record then
1275 Scan; -- past RECORD
1276 Set_Null_Record_Present (Aggregate_Node, True);
1278 return Aggregate_Node;
1281 Restore_Scan_State (Scan_State); -- to NULL that must be expr
1285 if Token /= Tok_Others then
1286 Save_Scan_State (Scan_State);
1287 Expr_Node := P_Expression;
1294 elsif Token = Tok_Right_Paren or else Token in Token_Class_Eterm then
1295 if Nkind (Expr_Node) = N_Attribute_Reference
1296 and then Attribute_Name (Expr_Node) = Name_Range
1299 ("|parentheses not allowed for range attribute", Lparen_Sloc);
1300 Scan; -- past right paren
1304 -- Bump paren count of expression
1306 if Expr_Node /= Error then
1307 Set_Paren_Count (Expr_Node, Paren_Count (Expr_Node) + 1);
1310 T_Right_Paren; -- past right paren (error message if none)
1313 -- Normal aggregate case
1316 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1322 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1326 -- Prepare to scan list of component associations
1328 Expr_List := No_List; -- don't set yet, maybe all named entries
1329 Assoc_List := No_List; -- don't set yet, maybe all positional entries
1331 -- This loop scans through component associations. On entry to the
1332 -- loop, an expression has been scanned at the start of the current
1333 -- association unless initial token was OTHERS, in which case
1334 -- Expr_Node is set to Empty.
1337 -- Deal with others association first. This is a named association
1339 if No (Expr_Node) then
1340 if No (Assoc_List) then
1341 Assoc_List := New_List;
1344 Append (P_Record_Or_Array_Component_Association, Assoc_List);
1346 -- Improper use of WITH
1348 elsif Token = Tok_With then
1349 Error_Msg_SC ("WITH must be preceded by single expression in " &
1350 "extension aggregate");
1353 -- Range attribute can only appear as part of a discrete choice list
1355 elsif Nkind (Expr_Node) = N_Attribute_Reference
1356 and then Attribute_Name (Expr_Node) = Name_Range
1357 and then Token /= Tok_Arrow
1358 and then Token /= Tok_Vertical_Bar
1360 Bad_Range_Attribute (Sloc (Expr_Node));
1363 -- Assume positional case if comma, right paren, or literal or
1364 -- identifier or OTHERS follows (the latter cases are missing
1365 -- comma cases). Also assume positional if a semicolon follows,
1366 -- which can happen if there are missing parens
1368 elsif Token = Tok_Comma
1369 or else Token = Tok_Right_Paren
1370 or else Token = Tok_Others
1371 or else Token in Token_Class_Lit_Or_Name
1372 or else Token = Tok_Semicolon
1374 if Present (Assoc_List) then
1375 Error_Msg_BC -- CODEFIX
1376 ("""='>"" expected (positional association cannot follow " &
1377 "named association)");
1380 if No (Expr_List) then
1381 Expr_List := New_List;
1384 Append (Expr_Node, Expr_List);
1386 -- Check for aggregate followed by left parent, maybe missing comma
1388 elsif Nkind (Expr_Node) = N_Aggregate
1389 and then Token = Tok_Left_Paren
1393 if No (Expr_List) then
1394 Expr_List := New_List;
1397 Append (Expr_Node, Expr_List);
1399 -- Anything else is assumed to be a named association
1402 Restore_Scan_State (Scan_State); -- to start of expression
1404 if No (Assoc_List) then
1405 Assoc_List := New_List;
1408 Append (P_Record_Or_Array_Component_Association, Assoc_List);
1411 exit when not Comma_Present;
1413 -- If we are at an expression terminator, something is seriously
1414 -- wrong, so let's get out now, before we start eating up stuff
1415 -- that doesn't belong to us!
1417 if Token in Token_Class_Eterm then
1418 Error_Msg_AP ("expecting expression or component association");
1422 -- Deal with misused box
1424 if Token = Tok_Box then
1427 -- Otherwise initiate for reentry to top of loop by scanning an
1428 -- initial expression, unless the first token is OTHERS.
1430 elsif Token = Tok_Others then
1434 Save_Scan_State (Scan_State); -- at start of expression
1435 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
1440 -- All component associations (positional and named) have been scanned
1443 Set_Expressions (Aggregate_Node, Expr_List);
1444 Set_Component_Associations (Aggregate_Node, Assoc_List);
1445 return Aggregate_Node;
1446 end P_Aggregate_Or_Paren_Expr;
1448 ------------------------------------------------
1449 -- 4.3 Record or Array Component Association --
1450 ------------------------------------------------
1452 -- RECORD_COMPONENT_ASSOCIATION ::=
1453 -- [COMPONENT_CHOICE_LIST =>] EXPRESSION
1454 -- | COMPONENT_CHOICE_LIST => <>
1456 -- COMPONENT_CHOICE_LIST =>
1457 -- component_SELECTOR_NAME {| component_SELECTOR_NAME}
1460 -- ARRAY_COMPONENT_ASSOCIATION ::=
1461 -- DISCRETE_CHOICE_LIST => EXPRESSION
1462 -- | DISCRETE_CHOICE_LIST => <>
1464 -- Note: this routine only handles the named cases, including others.
1465 -- Cases where the component choice list is not present have already
1466 -- been handled directly.
1468 -- Error recovery: can raise Error_Resync
1470 -- Note: RECORD_COMPONENT_ASSOCIATION and ARRAY_COMPONENT_ASSOCIATION
1471 -- rules have been extended to give support to Ada 2005 limited
1472 -- aggregates (AI-287)
1474 function P_Record_Or_Array_Component_Association return Node_Id is
1475 Assoc_Node : Node_Id;
1478 Assoc_Node := New_Node (N_Component_Association, Token_Ptr);
1479 Set_Choices (Assoc_Node, P_Discrete_Choice_List);
1480 Set_Sloc (Assoc_Node, Token_Ptr);
1483 if Token = Tok_Box then
1485 -- Ada 2005(AI-287): The box notation is used to indicate the
1486 -- default initialization of aggregate components
1488 if Ada_Version < Ada_2005 then
1490 ("component association with '<'> is an Ada 2005 extension");
1491 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1494 Set_Box_Present (Assoc_Node);
1497 Set_Expression (Assoc_Node, P_Expression);
1501 end P_Record_Or_Array_Component_Association;
1503 -----------------------------
1504 -- 4.3.1 Record Aggregate --
1505 -----------------------------
1507 -- Case of enumeration aggregate is parsed by P_Aggregate (4.3)
1508 -- All other cases are parsed by P_Aggregate_Or_Paren_Expr (4.3)
1510 ----------------------------------------------
1511 -- 4.3.1 Record Component Association List --
1512 ----------------------------------------------
1514 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1516 ----------------------------------
1517 -- 4.3.1 Component Choice List --
1518 ----------------------------------
1520 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1522 --------------------------------
1523 -- 4.3.1 Extension Aggregate --
1524 --------------------------------
1526 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1528 --------------------------
1529 -- 4.3.1 Ancestor Part --
1530 --------------------------
1532 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1534 ----------------------------
1535 -- 4.3.1 Array Aggregate --
1536 ----------------------------
1538 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1540 ---------------------------------------
1541 -- 4.3.1 Positional Array Aggregate --
1542 ---------------------------------------
1544 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1546 ----------------------------------
1547 -- 4.3.1 Named Array Aggregate --
1548 ----------------------------------
1550 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1552 ----------------------------------------
1553 -- 4.3.1 Array Component Association --
1554 ----------------------------------------
1556 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1558 ---------------------
1559 -- 4.4 Expression --
1560 ---------------------
1563 -- RELATION {and RELATION} | RELATION {and then RELATION}
1564 -- | RELATION {or RELATION} | RELATION {or else RELATION}
1565 -- | RELATION {xor RELATION}
1567 -- On return, Expr_Form indicates the categorization of the expression
1568 -- EF_Range_Attr is not a possible value (if a range attribute is found,
1569 -- an error message is given, and Error is returned).
1571 -- Error recovery: cannot raise Error_Resync
1573 function P_Expression return Node_Id is
1574 Logical_Op : Node_Kind;
1575 Prev_Logical_Op : Node_Kind;
1576 Op_Location : Source_Ptr;
1581 Node1 := P_Relation;
1583 if Token in Token_Class_Logop then
1584 Prev_Logical_Op := N_Empty;
1587 Op_Location := Token_Ptr;
1588 Logical_Op := P_Logical_Operator;
1590 if Prev_Logical_Op /= N_Empty and then
1591 Logical_Op /= Prev_Logical_Op
1594 ("mixed logical operators in expression", Op_Location);
1595 Prev_Logical_Op := N_Empty;
1597 Prev_Logical_Op := Logical_Op;
1601 Node1 := New_Op_Node (Logical_Op, Op_Location);
1602 Set_Left_Opnd (Node1, Node2);
1603 Set_Right_Opnd (Node1, P_Relation);
1604 exit when Token not in Token_Class_Logop;
1607 Expr_Form := EF_Non_Simple;
1610 if Token = Tok_Apostrophe then
1611 Bad_Range_Attribute (Token_Ptr);
1618 -- This function is identical to the normal P_Expression, except that it
1619 -- also permits the appearence of a case of conditional expression without
1620 -- the usual surrounding parentheses.
1622 function P_Expression_If_OK return Node_Id is
1624 if Token = Tok_Case then
1625 return P_Case_Expression;
1626 elsif Token = Tok_If then
1627 return P_Conditional_Expression;
1629 return P_Expression;
1631 end P_Expression_If_OK;
1633 -- This function is identical to the normal P_Expression, except that it
1634 -- checks that the expression scan did not stop on a right paren. It is
1635 -- called in all contexts where a right parenthesis cannot legitimately
1636 -- follow an expression.
1638 -- Error recovery: can not raise Error_Resync
1640 function P_Expression_No_Right_Paren return Node_Id is
1641 Expr : constant Node_Id := P_Expression;
1643 Ignore (Tok_Right_Paren);
1645 end P_Expression_No_Right_Paren;
1647 ----------------------------------------
1648 -- 4.4 Expression_Or_Range_Attribute --
1649 ----------------------------------------
1652 -- RELATION {and RELATION} | RELATION {and then RELATION}
1653 -- | RELATION {or RELATION} | RELATION {or else RELATION}
1654 -- | RELATION {xor RELATION}
1656 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
1658 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
1660 -- On return, Expr_Form indicates the categorization of the expression
1661 -- and EF_Range_Attr is one of the possibilities.
1663 -- Error recovery: cannot raise Error_Resync
1665 -- In the grammar, a RANGE attribute is simply a name, but its use is
1666 -- highly restricted, so in the parser, we do not regard it as a name.
1667 -- Instead, P_Name returns without scanning the 'RANGE part of the
1668 -- attribute, and P_Expression_Or_Range_Attribute handles the range
1669 -- attribute reference. In the normal case where a range attribute is
1670 -- not allowed, an error message is issued by P_Expression.
1672 function P_Expression_Or_Range_Attribute return Node_Id is
1673 Logical_Op : Node_Kind;
1674 Prev_Logical_Op : Node_Kind;
1675 Op_Location : Source_Ptr;
1678 Attr_Node : Node_Id;
1681 Node1 := P_Relation;
1683 if Token = Tok_Apostrophe then
1684 Attr_Node := P_Range_Attribute_Reference (Node1);
1685 Expr_Form := EF_Range_Attr;
1688 elsif Token in Token_Class_Logop then
1689 Prev_Logical_Op := N_Empty;
1692 Op_Location := Token_Ptr;
1693 Logical_Op := P_Logical_Operator;
1695 if Prev_Logical_Op /= N_Empty and then
1696 Logical_Op /= Prev_Logical_Op
1699 ("mixed logical operators in expression", Op_Location);
1700 Prev_Logical_Op := N_Empty;
1702 Prev_Logical_Op := Logical_Op;
1706 Node1 := New_Op_Node (Logical_Op, Op_Location);
1707 Set_Left_Opnd (Node1, Node2);
1708 Set_Right_Opnd (Node1, P_Relation);
1709 exit when Token not in Token_Class_Logop;
1712 Expr_Form := EF_Non_Simple;
1715 if Token = Tok_Apostrophe then
1716 Bad_Range_Attribute (Token_Ptr);
1721 end P_Expression_Or_Range_Attribute;
1723 -- Version that allows a non-parenthesized case or conditional expression
1725 function P_Expression_Or_Range_Attribute_If_OK return Node_Id is
1727 if Token = Tok_Case then
1728 return P_Case_Expression;
1729 elsif Token = Tok_If then
1730 return P_Conditional_Expression;
1732 return P_Expression_Or_Range_Attribute;
1734 end P_Expression_Or_Range_Attribute_If_OK;
1741 -- SIMPLE_EXPRESSION [RELATIONAL_OPERATOR SIMPLE_EXPRESSION]
1742 -- | SIMPLE_EXPRESSION [not] in RANGE
1743 -- | SIMPLE_EXPRESSION [not] in SUBTYPE_MARK
1745 -- On return, Expr_Form indicates the categorization of the expression
1747 -- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
1748 -- EF_Simple_Name and the following token is RANGE (range attribute case).
1750 -- Error recovery: cannot raise Error_Resync. If an error occurs within an
1751 -- expression, then tokens are scanned until either a non-expression token,
1752 -- a right paren (not matched by a left paren) or a comma, is encountered.
1754 function P_Relation return Node_Id is
1755 Node1, Node2 : Node_Id;
1759 Node1 := P_Simple_Expression;
1761 if Token not in Token_Class_Relop then
1765 -- Here we have a relational operator following. If so then scan it
1766 -- out. Note that the assignment symbol := is treated as a relational
1767 -- operator to improve the error recovery when it is misused for =.
1768 -- P_Relational_Operator also parses the IN and NOT IN operations.
1771 Node2 := New_Op_Node (P_Relational_Operator, Optok);
1772 Set_Left_Opnd (Node2, Node1);
1774 -- Case of IN or NOT IN
1776 if Prev_Token = Tok_In then
1777 P_Membership_Test (Node2);
1779 -- Case of relational operator (= /= < <= > >=)
1782 Set_Right_Opnd (Node2, P_Simple_Expression);
1785 Expr_Form := EF_Non_Simple;
1787 if Token in Token_Class_Relop then
1788 Error_Msg_SC ("unexpected relational operator");
1795 -- If any error occurs, then scan to the next expression terminator symbol
1796 -- or comma or right paren at the outer (i.e. current) parentheses level.
1797 -- The flags are set to indicate a normal simple expression.
1800 when Error_Resync =>
1802 Expr_Form := EF_Simple;
1806 ----------------------------
1807 -- 4.4 Simple Expression --
1808 ----------------------------
1810 -- SIMPLE_EXPRESSION ::=
1811 -- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
1813 -- On return, Expr_Form indicates the categorization of the expression
1815 -- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
1816 -- EF_Simple_Name and the following token is RANGE (range attribute case).
1818 -- Error recovery: cannot raise Error_Resync. If an error occurs within an
1819 -- expression, then tokens are scanned until either a non-expression token,
1820 -- a right paren (not matched by a left paren) or a comma, is encountered.
1822 -- Note: P_Simple_Expression is called only internally by higher level
1823 -- expression routines. In cases in the grammar where a simple expression
1824 -- is required, the approach is to scan an expression, and then post an
1825 -- appropriate error message if the expression obtained is not simple. This
1826 -- gives better error recovery and treatment.
1828 function P_Simple_Expression return Node_Id is
1829 Scan_State : Saved_Scan_State;
1832 Tokptr : Source_Ptr;
1835 -- Check for cases starting with a name. There are two reasons for
1836 -- special casing. First speed things up by catching a common case
1837 -- without going through several routine layers. Second the caller must
1838 -- be informed via Expr_Form when the simple expression is a name.
1840 if Token in Token_Class_Name then
1843 -- Deal with apostrophe cases
1845 if Token = Tok_Apostrophe then
1846 Save_Scan_State (Scan_State); -- at apostrophe
1847 Scan; -- past apostrophe
1849 -- If qualified expression, scan it out and fall through
1851 if Token = Tok_Left_Paren then
1852 Node1 := P_Qualified_Expression (Node1);
1853 Expr_Form := EF_Simple;
1855 -- If range attribute, then we return with Token pointing to the
1856 -- apostrophe. Note: avoid the normal error check on exit. We
1857 -- know that the expression really is complete in this case!
1859 else -- Token = Tok_Range then
1860 Restore_Scan_State (Scan_State); -- to apostrophe
1861 Expr_Form := EF_Simple_Name;
1866 -- If an expression terminator follows, the previous processing
1867 -- completely scanned out the expression (a common case), and
1868 -- left Expr_Form set appropriately for returning to our caller.
1870 if Token in Token_Class_Sterm then
1873 -- If we do not have an expression terminator, then complete the
1874 -- scan of a simple expression. This code duplicates the code
1875 -- found in P_Term and P_Factor.
1878 if Token = Tok_Double_Asterisk then
1880 Style.Check_Exponentiation_Operator;
1883 Node2 := New_Op_Node (N_Op_Expon, Token_Ptr);
1885 Set_Left_Opnd (Node2, Node1);
1886 Set_Right_Opnd (Node2, P_Primary);
1891 exit when Token not in Token_Class_Mulop;
1892 Tokptr := Token_Ptr;
1893 Node2 := New_Op_Node (P_Multiplying_Operator, Tokptr);
1896 Style.Check_Binary_Operator;
1899 Scan; -- past operator
1900 Set_Left_Opnd (Node2, Node1);
1901 Set_Right_Opnd (Node2, P_Factor);
1906 exit when Token not in Token_Class_Binary_Addop;
1907 Tokptr := Token_Ptr;
1908 Node2 := New_Op_Node (P_Binary_Adding_Operator, Tokptr);
1911 Style.Check_Binary_Operator;
1914 Scan; -- past operator
1915 Set_Left_Opnd (Node2, Node1);
1916 Set_Right_Opnd (Node2, P_Term);
1920 Expr_Form := EF_Simple;
1923 -- Cases where simple expression does not start with a name
1926 -- Scan initial sign and initial Term
1928 if Token in Token_Class_Unary_Addop then
1929 Tokptr := Token_Ptr;
1930 Node1 := New_Op_Node (P_Unary_Adding_Operator, Tokptr);
1933 Style.Check_Unary_Plus_Or_Minus;
1936 Scan; -- past operator
1937 Set_Right_Opnd (Node1, P_Term);
1942 -- In the following, we special-case a sequence of concatenations of
1943 -- string literals, such as "aaa" & "bbb" & ... & "ccc", with nothing
1944 -- else mixed in. For such a sequence, we return a tree representing
1945 -- "" & "aaabbb...ccc" (a single concatenation). This is done only if
1946 -- the number of concatenations is large. If semantic analysis
1947 -- resolves the "&" to a predefined one, then this folding gives the
1948 -- right answer. Otherwise, semantic analysis will complain about a
1949 -- capacity-exceeded error. The purpose of this trick is to avoid
1950 -- creating a deeply nested tree, which would cause deep recursion
1951 -- during semantics, causing stack overflow. This way, we can handle
1952 -- enormous concatenations in the normal case of predefined "&". We
1953 -- first build up the normal tree, and then rewrite it if
1957 Num_Concats_Threshold : constant Positive := 1000;
1958 -- Arbitrary threshold value to enable optimization
1960 First_Node : constant Node_Id := Node1;
1961 Is_Strlit_Concat : Boolean;
1962 -- True iff we've parsed a sequence of concatenations of string
1963 -- literals, with nothing else mixed in.
1965 Num_Concats : Natural;
1966 -- Number of "&" operators if Is_Strlit_Concat is True
1970 Nkind (Node1) = N_String_Literal
1971 and then Token = Tok_Ampersand;
1974 -- Scan out sequence of terms separated by binary adding operators
1977 exit when Token not in Token_Class_Binary_Addop;
1978 Tokptr := Token_Ptr;
1979 Node2 := New_Op_Node (P_Binary_Adding_Operator, Tokptr);
1980 Scan; -- past operator
1981 Set_Left_Opnd (Node2, Node1);
1983 Set_Right_Opnd (Node2, Node1);
1985 -- Check if we're still concatenating string literals
1989 and then Nkind (Node2) = N_Op_Concat
1990 and then Nkind (Node1) = N_String_Literal;
1992 if Is_Strlit_Concat then
1993 Num_Concats := Num_Concats + 1;
1999 -- If we have an enormous series of concatenations of string
2000 -- literals, rewrite as explained above. The Is_Folded_In_Parser
2001 -- flag tells semantic analysis that if the "&" is not predefined,
2002 -- the folded value is wrong.
2005 and then Num_Concats >= Num_Concats_Threshold
2008 Empty_String_Val : String_Id;
2011 Strlit_Concat_Val : String_Id;
2012 -- Contains the folded value (which will be correct if the
2013 -- "&" operators are the predefined ones).
2016 -- For walking up the tree
2019 -- Folded node to replace Node1
2021 Loc : constant Source_Ptr := Sloc (First_Node);
2024 -- Walk up the tree starting at the leftmost string literal
2025 -- (First_Node), building up the Strlit_Concat_Val as we
2026 -- go. Note that we do not use recursion here -- the whole
2027 -- point is to avoid recursively walking that enormous tree.
2030 Store_String_Chars (Strval (First_Node));
2032 Cur_Node := Parent (First_Node);
2033 while Present (Cur_Node) loop
2034 pragma Assert (Nkind (Cur_Node) = N_Op_Concat and then
2035 Nkind (Right_Opnd (Cur_Node)) = N_String_Literal);
2037 Store_String_Chars (Strval (Right_Opnd (Cur_Node)));
2038 Cur_Node := Parent (Cur_Node);
2041 Strlit_Concat_Val := End_String;
2043 -- Create new folded node, and rewrite result with a concat-
2044 -- enation of an empty string literal and the folded node.
2047 Empty_String_Val := End_String;
2049 Make_Op_Concat (Loc,
2050 Make_String_Literal (Loc, Empty_String_Val),
2051 Make_String_Literal (Loc, Strlit_Concat_Val,
2052 Is_Folded_In_Parser => True));
2053 Rewrite (Node1, New_Node);
2058 -- All done, we clearly do not have name or numeric literal so this
2059 -- is a case of a simple expression which is some other possibility.
2061 Expr_Form := EF_Simple;
2064 -- Come here at end of simple expression, where we do a couple of
2065 -- special checks to improve error recovery.
2067 -- Special test to improve error recovery. If the current token
2068 -- is a period, then someone is trying to do selection on something
2069 -- that is not a name, e.g. a qualified expression.
2071 if Token = Tok_Dot then
2072 Error_Msg_SC ("prefix for selection is not a name");
2074 -- If qualified expression, comment and continue, otherwise something
2075 -- is pretty nasty so do an Error_Resync call.
2077 if Ada_Version < Ada_2012
2078 and then Nkind (Node1) = N_Qualified_Expression
2080 Error_Msg_SC ("\would be legal in Ada 2012 mode");
2086 -- Special test to improve error recovery: If the current token is
2087 -- not the first token on a line (as determined by checking the
2088 -- previous token position with the start of the current line),
2089 -- then we insist that we have an appropriate terminating token.
2090 -- Consider the following two examples:
2092 -- 1) if A nad B then ...
2097 -- In the first example, we would like to issue a binary operator
2098 -- expected message and resynchronize to the then. In the second
2099 -- example, we do not want to issue a binary operator message, so
2100 -- that instead we will get the missing semicolon message. This
2101 -- distinction is of course a heuristic which does not always work,
2102 -- but in practice it is quite effective.
2104 -- Note: the one case in which we do not go through this circuit is
2105 -- when we have scanned a range attribute and want to return with
2106 -- Token pointing to the apostrophe. The apostrophe is not normally
2107 -- an expression terminator, and is not in Token_Class_Sterm, but
2108 -- in this special case we know that the expression is complete.
2110 if not Token_Is_At_Start_Of_Line
2111 and then Token not in Token_Class_Sterm
2113 -- Normally the right error message is indeed that we expected a
2114 -- binary operator, but in the case of being between a right and left
2115 -- paren, e.g. in an aggregate, a more likely error is missing comma.
2117 if Prev_Token = Tok_Right_Paren and then Token = Tok_Left_Paren then
2120 Error_Msg_AP ("binary operator expected");
2129 -- If any error occurs, then scan to next expression terminator symbol
2130 -- or comma, right paren or vertical bar at the outer (i.e. current) paren
2131 -- level. Expr_Form is set to indicate a normal simple expression.
2134 when Error_Resync =>
2136 Expr_Form := EF_Simple;
2138 end P_Simple_Expression;
2140 -----------------------------------------------
2141 -- 4.4 Simple Expression or Range Attribute --
2142 -----------------------------------------------
2144 -- SIMPLE_EXPRESSION ::=
2145 -- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
2147 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
2149 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
2151 -- Error recovery: cannot raise Error_Resync
2153 function P_Simple_Expression_Or_Range_Attribute return Node_Id is
2155 Attr_Node : Node_Id;
2158 -- We don't just want to roar ahead and call P_Simple_Expression
2159 -- here, since we want to handle the case of a parenthesized range
2160 -- attribute cleanly.
2162 if Token = Tok_Left_Paren then
2164 Lptr : constant Source_Ptr := Token_Ptr;
2165 Scan_State : Saved_Scan_State;
2168 Save_Scan_State (Scan_State);
2169 Scan; -- past left paren
2170 Sexpr := P_Simple_Expression;
2172 if Token = Tok_Apostrophe then
2173 Attr_Node := P_Range_Attribute_Reference (Sexpr);
2174 Expr_Form := EF_Range_Attr;
2176 if Token = Tok_Right_Paren then
2177 Scan; -- scan past right paren if present
2180 Error_Msg ("parentheses not allowed for range attribute", Lptr);
2185 Restore_Scan_State (Scan_State);
2189 -- Here after dealing with parenthesized range attribute
2191 Sexpr := P_Simple_Expression;
2193 if Token = Tok_Apostrophe then
2194 Attr_Node := P_Range_Attribute_Reference (Sexpr);
2195 Expr_Form := EF_Range_Attr;
2201 end P_Simple_Expression_Or_Range_Attribute;
2207 -- TERM ::= FACTOR {MULTIPLYING_OPERATOR FACTOR}
2209 -- Error recovery: can raise Error_Resync
2211 function P_Term return Node_Id is
2212 Node1, Node2 : Node_Id;
2213 Tokptr : Source_Ptr;
2219 exit when Token not in Token_Class_Mulop;
2220 Tokptr := Token_Ptr;
2221 Node2 := New_Op_Node (P_Multiplying_Operator, Tokptr);
2222 Scan; -- past operator
2223 Set_Left_Opnd (Node2, Node1);
2224 Set_Right_Opnd (Node2, P_Factor);
2235 -- FACTOR ::= PRIMARY [** PRIMARY] | abs PRIMARY | not PRIMARY
2237 -- Error recovery: can raise Error_Resync
2239 function P_Factor return Node_Id is
2244 if Token = Tok_Abs then
2245 Node1 := New_Op_Node (N_Op_Abs, Token_Ptr);
2248 Style.Check_Abs_Not;
2252 Set_Right_Opnd (Node1, P_Primary);
2255 elsif Token = Tok_Not then
2256 Node1 := New_Op_Node (N_Op_Not, Token_Ptr);
2259 Style.Check_Abs_Not;
2263 Set_Right_Opnd (Node1, P_Primary);
2269 if Token = Tok_Double_Asterisk then
2270 Node2 := New_Op_Node (N_Op_Expon, Token_Ptr);
2272 Set_Left_Opnd (Node2, Node1);
2273 Set_Right_Opnd (Node2, P_Primary);
2286 -- NUMERIC_LITERAL | null
2287 -- | STRING_LITERAL | AGGREGATE
2288 -- | NAME | QUALIFIED_EXPRESSION
2289 -- | ALLOCATOR | (EXPRESSION)
2291 -- Error recovery: can raise Error_Resync
2293 function P_Primary return Node_Id is
2294 Scan_State : Saved_Scan_State;
2298 -- The loop runs more than once only if misplaced pragmas are found
2303 -- Name token can start a name, call or qualified expression, all
2304 -- of which are acceptable possibilities for primary. Note also
2305 -- that string literal is included in name (as operator symbol)
2306 -- and type conversion is included in name (as indexed component).
2308 when Tok_Char_Literal | Tok_Operator_Symbol | Tok_Identifier =>
2311 -- All done unless apostrophe follows
2313 if Token /= Tok_Apostrophe then
2316 -- Apostrophe following means that we have either just parsed
2317 -- the subtype mark of a qualified expression, or the prefix
2318 -- or a range attribute.
2320 else -- Token = Tok_Apostrophe
2321 Save_Scan_State (Scan_State); -- at apostrophe
2322 Scan; -- past apostrophe
2324 -- If range attribute, then this is always an error, since
2325 -- the only legitimate case (where the scanned expression is
2326 -- a qualified simple name) is handled at the level of the
2327 -- Simple_Expression processing. This case corresponds to a
2328 -- usage such as 3 + A'Range, which is always illegal.
2330 if Token = Tok_Range then
2331 Restore_Scan_State (Scan_State); -- to apostrophe
2332 Bad_Range_Attribute (Token_Ptr);
2335 -- If left paren, then we have a qualified expression.
2336 -- Note that P_Name guarantees that in this case, where
2337 -- Token = Tok_Apostrophe on return, the only two possible
2338 -- tokens following the apostrophe are left paren and
2339 -- RANGE, so we know we have a left paren here.
2341 else -- Token = Tok_Left_Paren
2342 return P_Qualified_Expression (Node1);
2347 -- Numeric or string literal
2349 when Tok_Integer_Literal |
2351 Tok_String_Literal =>
2353 Node1 := Token_Node;
2354 Scan; -- past number
2357 -- Left paren, starts aggregate or parenthesized expression
2359 when Tok_Left_Paren =>
2361 Expr : constant Node_Id := P_Aggregate_Or_Paren_Expr;
2364 if Nkind (Expr) = N_Attribute_Reference
2365 and then Attribute_Name (Expr) = Name_Range
2367 Bad_Range_Attribute (Sloc (Expr));
2382 return New_Node (N_Null, Prev_Token_Ptr);
2384 -- Pragma, not allowed here, so just skip past it
2387 P_Pragmas_Misplaced;
2389 -- Deal with IF (possible unparenthesized conditional expression)
2393 -- If this looks like a real if, defined as an IF appearing at
2394 -- the start of a new line, then we consider we have a missing
2397 if Token_Is_At_Start_Of_Line then
2398 Error_Msg_AP ("missing operand");
2401 -- If this looks like a conditional expression, then treat it
2402 -- that way with an error message.
2404 elsif Ada_Version >= Ada_2012 then
2406 ("conditional expression must be parenthesized");
2407 return P_Conditional_Expression;
2409 -- Otherwise treat as misused identifier
2412 return P_Identifier;
2415 -- Deal with CASE (possible unparenthesized case expression)
2419 -- If this looks like a real case, defined as a CASE appearing
2420 -- the start of a new line, then we consider we have a missing
2423 if Token_Is_At_Start_Of_Line then
2424 Error_Msg_AP ("missing operand");
2427 -- If this looks like a case expression, then treat it that way
2428 -- with an error message.
2430 elsif Ada_Version >= Ada_2012 then
2431 Error_Msg_SC ("case expression must be parenthesized");
2432 return P_Case_Expression;
2434 -- Otherwise treat as misused identifier
2437 return P_Identifier;
2440 -- Anything else is illegal as the first token of a primary, but
2441 -- we test for a reserved identifier so that it is treated nicely
2444 if Is_Reserved_Identifier then
2445 return P_Identifier;
2447 elsif Prev_Token = Tok_Comma then
2448 Error_Msg_SP -- CODEFIX
2449 ("|extra "","" ignored");
2453 Error_Msg_AP ("missing operand");
2461 ---------------------------
2462 -- 4.5 Logical Operator --
2463 ---------------------------
2465 -- LOGICAL_OPERATOR ::= and | or | xor
2467 -- Note: AND THEN and OR ELSE are also treated as logical operators
2468 -- by the parser (even though they are not operators semantically)
2470 -- The value returned is the appropriate Node_Kind code for the operator
2471 -- On return, Token points to the token following the scanned operator.
2473 -- The caller has checked that the first token is a legitimate logical
2474 -- operator token (i.e. is either XOR, AND, OR).
2476 -- Error recovery: cannot raise Error_Resync
2478 function P_Logical_Operator return Node_Kind is
2480 if Token = Tok_And then
2482 Style.Check_Binary_Operator;
2487 if Token = Tok_Then then
2494 elsif Token = Tok_Or then
2496 Style.Check_Binary_Operator;
2501 if Token = Tok_Else then
2508 else -- Token = Tok_Xor
2510 Style.Check_Binary_Operator;
2516 end P_Logical_Operator;
2518 ------------------------------
2519 -- 4.5 Relational Operator --
2520 ------------------------------
2522 -- RELATIONAL_OPERATOR ::= = | /= | < | <= | > | >=
2524 -- The value returned is the appropriate Node_Kind code for the operator.
2525 -- On return, Token points to the operator token, NOT past it.
2527 -- The caller has checked that the first token is a legitimate relational
2528 -- operator token (i.e. is one of the operator tokens listed above).
2530 -- Error recovery: cannot raise Error_Resync
2532 function P_Relational_Operator return Node_Kind is
2533 Op_Kind : Node_Kind;
2534 Relop_Node : constant array (Token_Class_Relop) of Node_Kind :=
2535 (Tok_Less => N_Op_Lt,
2536 Tok_Equal => N_Op_Eq,
2537 Tok_Greater => N_Op_Gt,
2538 Tok_Not_Equal => N_Op_Ne,
2539 Tok_Greater_Equal => N_Op_Ge,
2540 Tok_Less_Equal => N_Op_Le,
2542 Tok_Not => N_Not_In,
2543 Tok_Box => N_Op_Ne);
2546 if Token = Tok_Box then
2547 Error_Msg_SC -- CODEFIX
2548 ("|""'<'>"" should be ""/=""");
2551 Op_Kind := Relop_Node (Token);
2554 Style.Check_Binary_Operator;
2557 Scan; -- past operator token
2559 if Prev_Token = Tok_Not then
2564 end P_Relational_Operator;
2566 ---------------------------------
2567 -- 4.5 Binary Adding Operator --
2568 ---------------------------------
2570 -- BINARY_ADDING_OPERATOR ::= + | - | &
2572 -- The value returned is the appropriate Node_Kind code for the operator.
2573 -- On return, Token points to the operator token (NOT past it).
2575 -- The caller has checked that the first token is a legitimate adding
2576 -- operator token (i.e. is one of the operator tokens listed above).
2578 -- Error recovery: cannot raise Error_Resync
2580 function P_Binary_Adding_Operator return Node_Kind is
2581 Addop_Node : constant array (Token_Class_Binary_Addop) of Node_Kind :=
2582 (Tok_Ampersand => N_Op_Concat,
2583 Tok_Minus => N_Op_Subtract,
2584 Tok_Plus => N_Op_Add);
2586 return Addop_Node (Token);
2587 end P_Binary_Adding_Operator;
2589 --------------------------------
2590 -- 4.5 Unary Adding Operator --
2591 --------------------------------
2593 -- UNARY_ADDING_OPERATOR ::= + | -
2595 -- The value returned is the appropriate Node_Kind code for the operator.
2596 -- On return, Token points to the operator token (NOT past it).
2598 -- The caller has checked that the first token is a legitimate adding
2599 -- operator token (i.e. is one of the operator tokens listed above).
2601 -- Error recovery: cannot raise Error_Resync
2603 function P_Unary_Adding_Operator return Node_Kind is
2604 Addop_Node : constant array (Token_Class_Unary_Addop) of Node_Kind :=
2605 (Tok_Minus => N_Op_Minus,
2606 Tok_Plus => N_Op_Plus);
2608 return Addop_Node (Token);
2609 end P_Unary_Adding_Operator;
2611 -------------------------------
2612 -- 4.5 Multiplying Operator --
2613 -------------------------------
2615 -- MULTIPLYING_OPERATOR ::= * | / | mod | rem
2617 -- The value returned is the appropriate Node_Kind code for the operator.
2618 -- On return, Token points to the operator token (NOT past it).
2620 -- The caller has checked that the first token is a legitimate multiplying
2621 -- operator token (i.e. is one of the operator tokens listed above).
2623 -- Error recovery: cannot raise Error_Resync
2625 function P_Multiplying_Operator return Node_Kind is
2626 Mulop_Node : constant array (Token_Class_Mulop) of Node_Kind :=
2627 (Tok_Asterisk => N_Op_Multiply,
2628 Tok_Mod => N_Op_Mod,
2629 Tok_Rem => N_Op_Rem,
2630 Tok_Slash => N_Op_Divide);
2632 return Mulop_Node (Token);
2633 end P_Multiplying_Operator;
2635 --------------------------------------
2636 -- 4.5 Highest Precedence Operator --
2637 --------------------------------------
2639 -- Parsed by P_Factor (4.4)
2641 -- Note: this rule is not in fact used by the grammar at any point!
2643 --------------------------
2644 -- 4.6 Type Conversion --
2645 --------------------------
2647 -- Parsed by P_Primary as a Name (4.1)
2649 -------------------------------
2650 -- 4.7 Qualified Expression --
2651 -------------------------------
2653 -- QUALIFIED_EXPRESSION ::=
2654 -- SUBTYPE_MARK ' (EXPRESSION) | SUBTYPE_MARK ' AGGREGATE
2656 -- The caller has scanned the name which is the Subtype_Mark parameter
2657 -- and scanned past the single quote following the subtype mark. The
2658 -- caller has not checked that this name is in fact appropriate for
2659 -- a subtype mark name (i.e. it is a selected component or identifier).
2661 -- Error_Recovery: cannot raise Error_Resync
2663 function P_Qualified_Expression (Subtype_Mark : Node_Id) return Node_Id is
2664 Qual_Node : Node_Id;
2666 Qual_Node := New_Node (N_Qualified_Expression, Prev_Token_Ptr);
2667 Set_Subtype_Mark (Qual_Node, Check_Subtype_Mark (Subtype_Mark));
2668 Set_Expression (Qual_Node, P_Aggregate_Or_Paren_Expr);
2670 end P_Qualified_Expression;
2672 --------------------
2674 --------------------
2677 -- new [NULL_EXCLUSION] SUBTYPE_INDICATION | new QUALIFIED_EXPRESSION
2679 -- The caller has checked that the initial token is NEW
2681 -- Error recovery: can raise Error_Resync
2683 function P_Allocator return Node_Id is
2684 Alloc_Node : Node_Id;
2685 Type_Node : Node_Id;
2686 Null_Exclusion_Present : Boolean;
2689 Alloc_Node := New_Node (N_Allocator, Token_Ptr);
2692 -- Scan Null_Exclusion if present (Ada 2005 (AI-231))
2694 Null_Exclusion_Present := P_Null_Exclusion;
2695 Set_Null_Exclusion_Present (Alloc_Node, Null_Exclusion_Present);
2696 Type_Node := P_Subtype_Mark_Resync;
2698 if Token = Tok_Apostrophe then
2699 Scan; -- past apostrophe
2700 Set_Expression (Alloc_Node, P_Qualified_Expression (Type_Node));
2704 P_Subtype_Indication (Type_Node, Null_Exclusion_Present));
2710 -----------------------
2711 -- P_Case_Expression --
2712 -----------------------
2714 function P_Case_Expression return Node_Id is
2715 Loc : constant Source_Ptr := Token_Ptr;
2716 Case_Node : Node_Id;
2717 Save_State : Saved_Scan_State;
2720 if Ada_Version < Ada_2012 then
2721 Error_Msg_SC ("|case expression is an Ada 2012 feature");
2722 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2727 Make_Case_Expression (Loc,
2728 Expression => P_Expression_No_Right_Paren,
2729 Alternatives => New_List);
2732 -- We now have scanned out CASE expression IS, scan alternatives
2736 Append_To (Alternatives (Case_Node), P_Case_Expression_Alternative);
2738 -- Missing comma if WHEN (more alternatives present)
2740 if Token = Tok_When then
2743 -- If comma/WHEN, skip comma and we have another alternative
2745 elsif Token = Tok_Comma then
2746 Save_Scan_State (Save_State);
2749 if Token /= Tok_When then
2750 Restore_Scan_State (Save_State);
2754 -- If no comma or WHEN, definitely done
2761 -- If we have an END CASE, diagnose as not needed
2763 if Token = Tok_End then
2764 Error_Msg_SC ("`END CASE` not allowed at end of case expression");
2767 if Token = Tok_Case then
2772 -- Return the Case_Expression node
2775 end P_Case_Expression;
2777 -----------------------------------
2778 -- P_Case_Expression_Alternative --
2779 -----------------------------------
2781 -- CASE_STATEMENT_ALTERNATIVE ::=
2782 -- when DISCRETE_CHOICE_LIST =>
2785 -- The caller has checked that and scanned past the initial WHEN token
2786 -- Error recovery: can raise Error_Resync
2788 function P_Case_Expression_Alternative return Node_Id is
2789 Case_Alt_Node : Node_Id;
2791 Case_Alt_Node := New_Node (N_Case_Expression_Alternative, Token_Ptr);
2792 Set_Discrete_Choices (Case_Alt_Node, P_Discrete_Choice_List);
2794 Set_Expression (Case_Alt_Node, P_Expression);
2795 return Case_Alt_Node;
2796 end P_Case_Expression_Alternative;
2798 ------------------------------
2799 -- P_Conditional_Expression --
2800 ------------------------------
2802 function P_Conditional_Expression return Node_Id is
2803 Exprs : constant List_Id := New_List;
2804 Loc : constant Source_Ptr := Token_Ptr;
2806 State : Saved_Scan_State;
2809 Inside_Conditional_Expression := Inside_Conditional_Expression + 1;
2811 if Token = Tok_If and then Ada_Version < Ada_2012 then
2812 Error_Msg_SC ("|conditional expression is an Ada 2012 feature");
2813 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2816 Scan; -- past IF or ELSIF
2817 Append_To (Exprs, P_Condition);
2819 Append_To (Exprs, P_Expression);
2821 -- We now have scanned out IF expr THEN expr
2823 -- Check for common error of semicolon before the ELSE
2825 if Token = Tok_Semicolon then
2826 Save_Scan_State (State);
2827 Scan; -- past semicolon
2829 if Token = Tok_Else or else Token = Tok_Elsif then
2830 Error_Msg_SP -- CODEFIX
2831 ("|extra "";"" ignored");
2834 Restore_Scan_State (State);
2838 -- Scan out ELSIF sequence if present
2840 if Token = Tok_Elsif then
2841 Expr := P_Conditional_Expression;
2842 Set_Is_Elsif (Expr);
2843 Append_To (Exprs, Expr);
2845 -- Scan out ELSE phrase if present
2847 elsif Token = Tok_Else then
2849 -- Scan out ELSE expression
2852 Append_To (Exprs, P_Expression);
2854 -- Two expression case (implied True, filled in during semantics)
2860 -- If we have an END IF, diagnose as not needed
2862 if Token = Tok_End then
2864 ("`END IF` not allowed at end of conditional expression");
2867 if Token = Tok_If then
2872 Inside_Conditional_Expression := Inside_Conditional_Expression - 1;
2874 -- Return the Conditional_Expression node
2877 Make_Conditional_Expression (Loc,
2878 Expressions => Exprs);
2879 end P_Conditional_Expression;
2881 -----------------------
2882 -- P_Membership_Test --
2883 -----------------------
2885 procedure P_Membership_Test (N : Node_Id) is
2886 Alt : constant Node_Id :=
2887 P_Range_Or_Subtype_Mark
2888 (Allow_Simple_Expression => (Ada_Version >= Ada_2012));
2893 if Token = Tok_Vertical_Bar then
2894 if Ada_Version < Ada_2012 then
2895 Error_Msg_SC ("set notation is an Ada 2012 feature");
2896 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2899 Set_Alternatives (N, New_List (Alt));
2900 Set_Right_Opnd (N, Empty);
2902 -- Loop to accumulate alternatives
2904 while Token = Tok_Vertical_Bar loop
2905 Scan; -- past vertical bar
2908 P_Range_Or_Subtype_Mark (Allow_Simple_Expression => True));
2914 Set_Right_Opnd (N, Alt);
2915 Set_Alternatives (N, No_List);
2917 end P_Membership_Test;