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
673 Error_Msg_SP ("|~~no mixing of positional and named "
674 & "parameter association");
677 Restore_Scan_State (Scan_State); -- to Id
680 -- Otherwise it's just an expression after all, so backup
683 Restore_Scan_State (Scan_State); -- to Id
687 -- Here we have an expression after all, so stay in this state
689 Expr_Node := P_Expression_If_OK;
692 -- LP_State_Call corresponds to the situation in which at least
693 -- one instance of Id => Expression has been encountered, so we
694 -- know that we do not have a name, but rather a call. We enter
695 -- it with the scan pointer pointing to the next argument to scan,
696 -- and Arg_List containing the list of arguments scanned so far.
700 -- Test for case of Id => Expression (named parameter)
702 if Token = Tok_Identifier then
703 Save_Scan_State (Scan_State); -- at Id
704 Ident_Node := Token_Node;
707 -- Deal with => (allow := as erroneous substitute)
709 if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
710 Arg_Node := New_Node (N_Parameter_Association, Prev_Token_Ptr);
711 Set_Selector_Name (Arg_Node, Ident_Node);
713 Set_Explicit_Actual_Parameter (Arg_Node, P_Expression);
714 Append (Arg_Node, Arg_List);
716 -- If a comma follows, go back and scan next entry
718 if Comma_Present then
721 -- Otherwise we have the end of a call
724 Prefix_Node := Name_Node;
725 Name_Node := New_Node (N_Function_Call, Sloc (Prefix_Node));
726 Set_Name (Name_Node, Prefix_Node);
727 Set_Parameter_Associations (Name_Node, Arg_List);
730 if Token in Token_Class_Namext then
731 goto Scan_Name_Extension_OK;
733 -- This is a case of a call which cannot be a name
736 Expr_Form := EF_Name;
741 -- Not named parameter: Id started an expression after all
744 Restore_Scan_State (Scan_State); -- to Id
748 -- Here if entry did not start with Id => which means that it
749 -- is a positional parameter, which is not allowed, since we
750 -- have seen at least one named parameter already.
753 ("positional parameter association " &
754 "not allowed after named one");
756 Expr_Node := P_Expression_If_OK;
758 -- Leaving the '>' in an association is not unusual, so suggest
761 if Nkind (Expr_Node) = N_Op_Eq then
762 Error_Msg_N ("\maybe `='>` was intended", Expr_Node);
765 -- We go back to scanning out expressions, so that we do not get
766 -- multiple error messages when several positional parameters
767 -- follow a named parameter.
771 -- End of treatment for name extensions starting with left paren
773 -- End of loop through name extensions
777 -- This function parses a restricted form of Names which are either
778 -- designators, or designators preceded by a sequence of prefixes
779 -- that are direct names.
781 -- Error recovery: cannot raise Error_Resync
783 function P_Function_Name return Node_Id is
784 Designator_Node : Node_Id;
785 Prefix_Node : Node_Id;
786 Selector_Node : Node_Id;
787 Dot_Sloc : Source_Ptr := No_Location;
790 -- Prefix_Node is set to the gathered prefix so far, Empty means that
791 -- no prefix has been scanned. This allows us to build up the result
792 -- in the required right recursive manner.
794 Prefix_Node := Empty;
796 -- Loop through prefixes
799 Designator_Node := Token_Node;
801 if Token not in Token_Class_Desig then
802 return P_Identifier; -- let P_Identifier issue the error message
804 else -- Token in Token_Class_Desig
805 Scan; -- past designator
806 exit when Token /= Tok_Dot;
809 -- Here at a dot, with token just before it in Designator_Node
811 if No (Prefix_Node) then
812 Prefix_Node := Designator_Node;
814 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
815 Set_Prefix (Selector_Node, Prefix_Node);
816 Set_Selector_Name (Selector_Node, Designator_Node);
817 Prefix_Node := Selector_Node;
820 Dot_Sloc := Token_Ptr;
824 -- Fall out of the loop having just scanned a designator
826 if No (Prefix_Node) then
827 return Designator_Node;
829 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
830 Set_Prefix (Selector_Node, Prefix_Node);
831 Set_Selector_Name (Selector_Node, Designator_Node);
832 return Selector_Node;
840 -- This function parses a restricted form of Names which are either
841 -- identifiers, or identifiers preceded by a sequence of prefixes
842 -- that are direct names.
844 -- Error recovery: cannot raise Error_Resync
846 function P_Qualified_Simple_Name return Node_Id is
847 Designator_Node : Node_Id;
848 Prefix_Node : Node_Id;
849 Selector_Node : Node_Id;
850 Dot_Sloc : Source_Ptr := No_Location;
853 -- Prefix node is set to the gathered prefix so far, Empty means that
854 -- no prefix has been scanned. This allows us to build up the result
855 -- in the required right recursive manner.
857 Prefix_Node := Empty;
859 -- Loop through prefixes
862 Designator_Node := Token_Node;
864 if Token = Tok_Identifier then
865 Scan; -- past identifier
866 exit when Token /= Tok_Dot;
868 elsif Token not in Token_Class_Desig then
869 return P_Identifier; -- let P_Identifier issue the error message
872 Scan; -- past designator
874 if Token /= Tok_Dot then
875 Error_Msg_SP ("identifier expected");
880 -- Here at a dot, with token just before it in Designator_Node
882 if No (Prefix_Node) then
883 Prefix_Node := Designator_Node;
885 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
886 Set_Prefix (Selector_Node, Prefix_Node);
887 Set_Selector_Name (Selector_Node, Designator_Node);
888 Prefix_Node := Selector_Node;
891 Dot_Sloc := Token_Ptr;
895 -- Fall out of the loop having just scanned an identifier
897 if No (Prefix_Node) then
898 return Designator_Node;
900 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
901 Set_Prefix (Selector_Node, Prefix_Node);
902 Set_Selector_Name (Selector_Node, Designator_Node);
903 return Selector_Node;
909 end P_Qualified_Simple_Name;
911 -- This procedure differs from P_Qualified_Simple_Name only in that it
912 -- raises Error_Resync if any error is encountered. It only returns after
913 -- scanning a valid qualified simple name.
915 -- Error recovery: can raise Error_Resync
917 function P_Qualified_Simple_Name_Resync return Node_Id is
918 Designator_Node : Node_Id;
919 Prefix_Node : Node_Id;
920 Selector_Node : Node_Id;
921 Dot_Sloc : Source_Ptr := No_Location;
924 Prefix_Node := Empty;
926 -- Loop through prefixes
929 Designator_Node := Token_Node;
931 if Token = Tok_Identifier then
932 Scan; -- past identifier
933 exit when Token /= Tok_Dot;
935 elsif Token not in Token_Class_Desig then
936 Discard_Junk_Node (P_Identifier); -- to issue the error message
940 Scan; -- past designator
942 if Token /= Tok_Dot then
943 Error_Msg_SP ("identifier expected");
948 -- Here at a dot, with token just before it in Designator_Node
950 if No (Prefix_Node) then
951 Prefix_Node := Designator_Node;
953 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
954 Set_Prefix (Selector_Node, Prefix_Node);
955 Set_Selector_Name (Selector_Node, Designator_Node);
956 Prefix_Node := Selector_Node;
959 Dot_Sloc := Token_Ptr;
963 -- Fall out of the loop having just scanned an identifier
965 if No (Prefix_Node) then
966 return Designator_Node;
968 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
969 Set_Prefix (Selector_Node, Prefix_Node);
970 Set_Selector_Name (Selector_Node, Designator_Node);
971 return Selector_Node;
973 end P_Qualified_Simple_Name_Resync;
975 ----------------------
976 -- 4.1 Direct_Name --
977 ----------------------
979 -- Parsed by P_Name and other functions in section 4.1
985 -- Parsed by P_Name (4.1)
987 -------------------------------
988 -- 4.1 Explicit Dereference --
989 -------------------------------
991 -- Parsed by P_Name (4.1)
993 -------------------------------
994 -- 4.1 Implicit_Dereference --
995 -------------------------------
997 -- Parsed by P_Name (4.1)
999 ----------------------------
1000 -- 4.1 Indexed Component --
1001 ----------------------------
1003 -- Parsed by P_Name (4.1)
1009 -- Parsed by P_Name (4.1)
1011 -----------------------------
1012 -- 4.1 Selected_Component --
1013 -----------------------------
1015 -- Parsed by P_Name (4.1)
1017 ------------------------
1018 -- 4.1 Selector Name --
1019 ------------------------
1021 -- Parsed by P_Name (4.1)
1023 ------------------------------
1024 -- 4.1 Attribute Reference --
1025 ------------------------------
1027 -- Parsed by P_Name (4.1)
1029 -------------------------------
1030 -- 4.1 Attribute Designator --
1031 -------------------------------
1033 -- Parsed by P_Name (4.1)
1035 --------------------------------------
1036 -- 4.1.4 Range Attribute Reference --
1037 --------------------------------------
1039 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
1041 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
1043 -- In the grammar, a RANGE attribute is simply a name, but its use is
1044 -- highly restricted, so in the parser, we do not regard it as a name.
1045 -- Instead, P_Name returns without scanning the 'RANGE part of the
1046 -- attribute, and the caller uses the following function to construct
1047 -- a range attribute in places where it is appropriate.
1049 -- Note that RANGE here is treated essentially as an identifier,
1050 -- rather than a reserved word.
1052 -- The caller has parsed the prefix, i.e. a name, and Token points to
1053 -- the apostrophe. The token after the apostrophe is known to be RANGE
1054 -- at this point. The prefix node becomes the prefix of the attribute.
1056 -- Error_Recovery: Cannot raise Error_Resync
1058 function P_Range_Attribute_Reference
1059 (Prefix_Node : Node_Id)
1062 Attr_Node : Node_Id;
1065 Attr_Node := New_Node (N_Attribute_Reference, Token_Ptr);
1066 Set_Prefix (Attr_Node, Prefix_Node);
1067 Scan; -- past apostrophe
1070 Style.Check_Attribute_Name (True);
1073 Set_Attribute_Name (Attr_Node, Name_Range);
1076 if Token = Tok_Left_Paren then
1077 Scan; -- past left paren
1078 Set_Expressions (Attr_Node, New_List (P_Expression_If_OK));
1083 end P_Range_Attribute_Reference;
1085 ---------------------------------------
1086 -- 4.1.4 Range Attribute Designator --
1087 ---------------------------------------
1089 -- Parsed by P_Range_Attribute_Reference (4.4)
1091 --------------------
1093 --------------------
1095 -- AGGREGATE ::= RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
1097 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3), except in the case where
1098 -- an aggregate is known to be required (code statement, extension
1099 -- aggregate), in which cases this routine performs the necessary check
1100 -- that we have an aggregate rather than a parenthesized expression
1102 -- Error recovery: can raise Error_Resync
1104 function P_Aggregate return Node_Id is
1105 Aggr_Sloc : constant Source_Ptr := Token_Ptr;
1106 Aggr_Node : constant Node_Id := P_Aggregate_Or_Paren_Expr;
1109 if Nkind (Aggr_Node) /= N_Aggregate
1111 Nkind (Aggr_Node) /= N_Extension_Aggregate
1114 ("aggregate may not have single positional component", Aggr_Sloc);
1121 ------------------------------------------------
1122 -- 4.3 Aggregate or Parenthesized Expression --
1123 ------------------------------------------------
1125 -- This procedure parses out either an aggregate or a parenthesized
1126 -- expression (these two constructs are closely related, since a
1127 -- parenthesized expression looks like an aggregate with a single
1128 -- positional component).
1131 -- RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
1133 -- RECORD_AGGREGATE ::= (RECORD_COMPONENT_ASSOCIATION_LIST)
1135 -- RECORD_COMPONENT_ASSOCIATION_LIST ::=
1136 -- RECORD_COMPONENT_ASSOCIATION {, RECORD_COMPONENT_ASSOCIATION}
1139 -- RECORD_COMPONENT_ASSOCIATION ::=
1140 -- [COMPONENT_CHOICE_LIST =>] EXPRESSION
1142 -- COMPONENT_CHOICE_LIST ::=
1143 -- component_SELECTOR_NAME {| component_SELECTOR_NAME}
1146 -- EXTENSION_AGGREGATE ::=
1147 -- (ANCESTOR_PART with RECORD_COMPONENT_ASSOCIATION_LIST)
1149 -- ANCESTOR_PART ::= EXPRESSION | SUBTYPE_MARK
1151 -- ARRAY_AGGREGATE ::=
1152 -- POSITIONAL_ARRAY_AGGREGATE | NAMED_ARRAY_AGGREGATE
1154 -- POSITIONAL_ARRAY_AGGREGATE ::=
1155 -- (EXPRESSION, EXPRESSION {, EXPRESSION})
1156 -- | (EXPRESSION {, EXPRESSION}, others => EXPRESSION)
1157 -- | (EXPRESSION {, EXPRESSION}, others => <>)
1159 -- NAMED_ARRAY_AGGREGATE ::=
1160 -- (ARRAY_COMPONENT_ASSOCIATION {, ARRAY_COMPONENT_ASSOCIATION})
1162 -- PRIMARY ::= (EXPRESSION);
1164 -- Error recovery: can raise Error_Resync
1166 -- Note: POSITIONAL_ARRAY_AGGREGATE rule has been extended to give support
1167 -- to Ada 2005 limited aggregates (AI-287)
1169 function P_Aggregate_Or_Paren_Expr return Node_Id is
1170 Aggregate_Node : Node_Id;
1171 Expr_List : List_Id;
1172 Assoc_List : List_Id;
1173 Expr_Node : Node_Id;
1174 Lparen_Sloc : Source_Ptr;
1175 Scan_State : Saved_Scan_State;
1177 procedure Box_Error;
1178 -- Called if <> is encountered as positional aggregate element. Issues
1179 -- error message and sets Expr_Node to Error.
1185 procedure Box_Error is
1187 if Ada_Version < Ada_2005 then
1188 Error_Msg_SC ("box in aggregate is an Ada 2005 extension");
1191 -- Ada 2005 (AI-287): The box notation is allowed only with named
1192 -- notation because positional notation might be error prone. For
1193 -- example, in "(X, <>, Y, <>)", there is no type associated with
1194 -- the boxes, so you might not be leaving out the components you
1195 -- thought you were leaving out.
1197 Error_Msg_SC ("(Ada 2005) box only allowed with named notation");
1202 -- Start of processing for P_Aggregate_Or_Paren_Expr
1205 Lparen_Sloc := Token_Ptr;
1208 -- Conditional expression case
1210 if Token = Tok_If then
1211 Expr_Node := P_Conditional_Expression;
1215 -- Case expression case
1217 elsif Token = Tok_Case then
1218 Expr_Node := P_Case_Expression;
1222 -- Quantified expression case
1224 elsif Token = Tok_For then
1225 Expr_Node := P_Quantified_Expression;
1229 -- Note: the mechanism used here of rescanning the initial expression
1230 -- is distinctly unpleasant, but it saves a lot of fiddling in scanning
1231 -- out the discrete choice list.
1233 -- Deal with expression and extension aggregate cases first
1235 elsif Token /= Tok_Others then
1236 Save_Scan_State (Scan_State); -- at start of expression
1238 -- Deal with (NULL RECORD) case
1240 if Token = Tok_Null then
1243 if Token = Tok_Record then
1244 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1245 Set_Null_Record_Present (Aggregate_Node, True);
1246 Scan; -- past RECORD
1248 return Aggregate_Node;
1250 Restore_Scan_State (Scan_State); -- to NULL that must be expr
1254 -- Scan expression, handling box appearing as positional argument
1256 if Token = Tok_Box then
1259 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
1262 -- Extension aggregate case
1264 if Token = Tok_With then
1265 if Nkind (Expr_Node) = N_Attribute_Reference
1266 and then Attribute_Name (Expr_Node) = Name_Range
1268 Bad_Range_Attribute (Sloc (Expr_Node));
1272 if Ada_Version = Ada_83 then
1273 Error_Msg_SC ("(Ada 83) extension aggregate not allowed");
1276 Aggregate_Node := New_Node (N_Extension_Aggregate, Lparen_Sloc);
1277 Set_Ancestor_Part (Aggregate_Node, Expr_Node);
1280 -- Deal with WITH NULL RECORD case
1282 if Token = Tok_Null then
1283 Save_Scan_State (Scan_State); -- at NULL
1286 if Token = Tok_Record then
1287 Scan; -- past RECORD
1288 Set_Null_Record_Present (Aggregate_Node, True);
1290 return Aggregate_Node;
1293 Restore_Scan_State (Scan_State); -- to NULL that must be expr
1297 if Token /= Tok_Others then
1298 Save_Scan_State (Scan_State);
1299 Expr_Node := P_Expression;
1306 elsif Token = Tok_Right_Paren or else Token in Token_Class_Eterm then
1307 if Nkind (Expr_Node) = N_Attribute_Reference
1308 and then Attribute_Name (Expr_Node) = Name_Range
1311 ("|parentheses not allowed for range attribute", Lparen_Sloc);
1312 Scan; -- past right paren
1316 -- Bump paren count of expression
1318 if Expr_Node /= Error then
1319 Set_Paren_Count (Expr_Node, Paren_Count (Expr_Node) + 1);
1322 T_Right_Paren; -- past right paren (error message if none)
1325 -- Normal aggregate case
1328 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1334 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1338 -- Prepare to scan list of component associations
1340 Expr_List := No_List; -- don't set yet, maybe all named entries
1341 Assoc_List := No_List; -- don't set yet, maybe all positional entries
1343 -- This loop scans through component associations. On entry to the
1344 -- loop, an expression has been scanned at the start of the current
1345 -- association unless initial token was OTHERS, in which case
1346 -- Expr_Node is set to Empty.
1349 -- Deal with others association first. This is a named association
1351 if No (Expr_Node) then
1352 if No (Assoc_List) then
1353 Assoc_List := New_List;
1356 Append (P_Record_Or_Array_Component_Association, Assoc_List);
1358 -- Improper use of WITH
1360 elsif Token = Tok_With then
1361 Error_Msg_SC ("WITH must be preceded by single expression in " &
1362 "extension aggregate");
1365 -- Range attribute can only appear as part of a discrete choice list
1367 elsif Nkind (Expr_Node) = N_Attribute_Reference
1368 and then Attribute_Name (Expr_Node) = Name_Range
1369 and then Token /= Tok_Arrow
1370 and then Token /= Tok_Vertical_Bar
1372 Bad_Range_Attribute (Sloc (Expr_Node));
1375 -- Assume positional case if comma, right paren, or literal or
1376 -- identifier or OTHERS follows (the latter cases are missing
1377 -- comma cases). Also assume positional if a semicolon follows,
1378 -- which can happen if there are missing parens
1380 elsif Token = Tok_Comma
1381 or else Token = Tok_Right_Paren
1382 or else Token = Tok_Others
1383 or else Token in Token_Class_Lit_Or_Name
1384 or else Token = Tok_Semicolon
1386 if Present (Assoc_List) then
1387 Error_Msg_BC -- CODEFIX
1388 ("""='>"" expected (positional association cannot follow " &
1389 "named association)");
1392 if No (Expr_List) then
1393 Expr_List := New_List;
1396 Append (Expr_Node, Expr_List);
1398 -- Check for aggregate followed by left parent, maybe missing comma
1400 elsif Nkind (Expr_Node) = N_Aggregate
1401 and then Token = Tok_Left_Paren
1405 if No (Expr_List) then
1406 Expr_List := New_List;
1409 Append (Expr_Node, Expr_List);
1411 -- Anything else is assumed to be a named association
1414 Restore_Scan_State (Scan_State); -- to start of expression
1416 if No (Assoc_List) then
1417 Assoc_List := New_List;
1420 Append (P_Record_Or_Array_Component_Association, Assoc_List);
1423 exit when not Comma_Present;
1425 -- If we are at an expression terminator, something is seriously
1426 -- wrong, so let's get out now, before we start eating up stuff
1427 -- that doesn't belong to us!
1429 if Token in Token_Class_Eterm then
1431 -- If Some becomes a keyword, the following is needed to make it
1432 -- acceptable in older versions of Ada.
1435 and then Ada_Version < Ada_2012
1437 Scan_Reserved_Identifier (False);
1440 ("expecting expression or component association");
1445 -- Deal with misused box
1447 if Token = Tok_Box then
1450 -- Otherwise initiate for reentry to top of loop by scanning an
1451 -- initial expression, unless the first token is OTHERS.
1453 elsif Token = Tok_Others then
1457 Save_Scan_State (Scan_State); -- at start of expression
1458 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
1463 -- All component associations (positional and named) have been scanned
1466 Set_Expressions (Aggregate_Node, Expr_List);
1467 Set_Component_Associations (Aggregate_Node, Assoc_List);
1468 return Aggregate_Node;
1469 end P_Aggregate_Or_Paren_Expr;
1471 ------------------------------------------------
1472 -- 4.3 Record or Array Component Association --
1473 ------------------------------------------------
1475 -- RECORD_COMPONENT_ASSOCIATION ::=
1476 -- [COMPONENT_CHOICE_LIST =>] EXPRESSION
1477 -- | COMPONENT_CHOICE_LIST => <>
1479 -- COMPONENT_CHOICE_LIST =>
1480 -- component_SELECTOR_NAME {| component_SELECTOR_NAME}
1483 -- ARRAY_COMPONENT_ASSOCIATION ::=
1484 -- DISCRETE_CHOICE_LIST => EXPRESSION
1485 -- | DISCRETE_CHOICE_LIST => <>
1487 -- Note: this routine only handles the named cases, including others.
1488 -- Cases where the component choice list is not present have already
1489 -- been handled directly.
1491 -- Error recovery: can raise Error_Resync
1493 -- Note: RECORD_COMPONENT_ASSOCIATION and ARRAY_COMPONENT_ASSOCIATION
1494 -- rules have been extended to give support to Ada 2005 limited
1495 -- aggregates (AI-287)
1497 function P_Record_Or_Array_Component_Association return Node_Id is
1498 Assoc_Node : Node_Id;
1501 Assoc_Node := New_Node (N_Component_Association, Token_Ptr);
1502 Set_Choices (Assoc_Node, P_Discrete_Choice_List);
1503 Set_Sloc (Assoc_Node, Token_Ptr);
1506 if Token = Tok_Box then
1508 -- Ada 2005(AI-287): The box notation is used to indicate the
1509 -- default initialization of aggregate components
1511 if Ada_Version < Ada_2005 then
1513 ("component association with '<'> is an Ada 2005 extension");
1514 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1517 Set_Box_Present (Assoc_Node);
1520 Set_Expression (Assoc_Node, P_Expression);
1524 end P_Record_Or_Array_Component_Association;
1526 -----------------------------
1527 -- 4.3.1 Record Aggregate --
1528 -----------------------------
1530 -- Case of enumeration aggregate is parsed by P_Aggregate (4.3)
1531 -- All other cases are parsed by P_Aggregate_Or_Paren_Expr (4.3)
1533 ----------------------------------------------
1534 -- 4.3.1 Record Component Association List --
1535 ----------------------------------------------
1537 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1539 ----------------------------------
1540 -- 4.3.1 Component Choice List --
1541 ----------------------------------
1543 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1545 --------------------------------
1546 -- 4.3.1 Extension Aggregate --
1547 --------------------------------
1549 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1551 --------------------------
1552 -- 4.3.1 Ancestor Part --
1553 --------------------------
1555 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1557 ----------------------------
1558 -- 4.3.1 Array Aggregate --
1559 ----------------------------
1561 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1563 ---------------------------------------
1564 -- 4.3.1 Positional Array Aggregate --
1565 ---------------------------------------
1567 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1569 ----------------------------------
1570 -- 4.3.1 Named Array Aggregate --
1571 ----------------------------------
1573 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1575 ----------------------------------------
1576 -- 4.3.1 Array Component Association --
1577 ----------------------------------------
1579 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1581 ---------------------
1582 -- 4.4 Expression --
1583 ---------------------
1585 -- This procedure parses EXPRESSION or CHOICE_EXPRESSION
1588 -- RELATION {LOGICAL_OPERATOR RELATION}
1590 -- CHOICE_EXPRESSION ::=
1591 -- CHOICE_RELATION {LOGICAL_OPERATOR CHOICE_RELATION}
1593 -- LOGICAL_OPERATOR ::= and | and then | or | or else | xor
1595 -- On return, Expr_Form indicates the categorization of the expression
1596 -- EF_Range_Attr is not a possible value (if a range attribute is found,
1597 -- an error message is given, and Error is returned).
1599 -- Error recovery: cannot raise Error_Resync
1601 function P_Expression return Node_Id is
1602 Logical_Op : Node_Kind;
1603 Prev_Logical_Op : Node_Kind;
1604 Op_Location : Source_Ptr;
1609 Node1 := P_Relation;
1611 if Token in Token_Class_Logop then
1612 Prev_Logical_Op := N_Empty;
1615 Op_Location := Token_Ptr;
1616 Logical_Op := P_Logical_Operator;
1618 if Prev_Logical_Op /= N_Empty and then
1619 Logical_Op /= Prev_Logical_Op
1622 ("mixed logical operators in expression", Op_Location);
1623 Prev_Logical_Op := N_Empty;
1625 Prev_Logical_Op := Logical_Op;
1629 Node1 := New_Op_Node (Logical_Op, Op_Location);
1630 Set_Left_Opnd (Node1, Node2);
1631 Set_Right_Opnd (Node1, P_Relation);
1632 exit when Token not in Token_Class_Logop;
1635 Expr_Form := EF_Non_Simple;
1638 if Token = Tok_Apostrophe then
1639 Bad_Range_Attribute (Token_Ptr);
1646 -- This function is identical to the normal P_Expression, except that it
1647 -- also permits the appearance of a case, conditional, or quantified
1648 -- expression without the usual surrounding parentheses.
1650 function P_Expression_If_OK return Node_Id is
1652 if Token = Tok_Case then
1653 return P_Case_Expression;
1655 elsif Token = Tok_If then
1656 return P_Conditional_Expression;
1658 elsif Token = Tok_For then
1659 return P_Quantified_Expression;
1662 return P_Expression;
1664 end P_Expression_If_OK;
1666 -- This function is identical to the normal P_Expression, except that it
1667 -- checks that the expression scan did not stop on a right paren. It is
1668 -- called in all contexts where a right parenthesis cannot legitimately
1669 -- follow an expression.
1671 -- Error recovery: can not raise Error_Resync
1673 function P_Expression_No_Right_Paren return Node_Id is
1674 Expr : constant Node_Id := P_Expression;
1676 Ignore (Tok_Right_Paren);
1678 end P_Expression_No_Right_Paren;
1680 ----------------------------------------
1681 -- 4.4 Expression_Or_Range_Attribute --
1682 ----------------------------------------
1685 -- RELATION {and RELATION} | RELATION {and then RELATION}
1686 -- | RELATION {or RELATION} | RELATION {or else RELATION}
1687 -- | RELATION {xor RELATION}
1689 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
1691 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
1693 -- On return, Expr_Form indicates the categorization of the expression
1694 -- and EF_Range_Attr is one of the possibilities.
1696 -- Error recovery: cannot raise Error_Resync
1698 -- In the grammar, a RANGE attribute is simply a name, but its use is
1699 -- highly restricted, so in the parser, we do not regard it as a name.
1700 -- Instead, P_Name returns without scanning the 'RANGE part of the
1701 -- attribute, and P_Expression_Or_Range_Attribute handles the range
1702 -- attribute reference. In the normal case where a range attribute is
1703 -- not allowed, an error message is issued by P_Expression.
1705 function P_Expression_Or_Range_Attribute return Node_Id is
1706 Logical_Op : Node_Kind;
1707 Prev_Logical_Op : Node_Kind;
1708 Op_Location : Source_Ptr;
1711 Attr_Node : Node_Id;
1714 Node1 := P_Relation;
1716 if Token = Tok_Apostrophe then
1717 Attr_Node := P_Range_Attribute_Reference (Node1);
1718 Expr_Form := EF_Range_Attr;
1721 elsif Token in Token_Class_Logop then
1722 Prev_Logical_Op := N_Empty;
1725 Op_Location := Token_Ptr;
1726 Logical_Op := P_Logical_Operator;
1728 if Prev_Logical_Op /= N_Empty and then
1729 Logical_Op /= Prev_Logical_Op
1732 ("mixed logical operators in expression", Op_Location);
1733 Prev_Logical_Op := N_Empty;
1735 Prev_Logical_Op := Logical_Op;
1739 Node1 := New_Op_Node (Logical_Op, Op_Location);
1740 Set_Left_Opnd (Node1, Node2);
1741 Set_Right_Opnd (Node1, P_Relation);
1742 exit when Token not in Token_Class_Logop;
1745 Expr_Form := EF_Non_Simple;
1748 if Token = Tok_Apostrophe then
1749 Bad_Range_Attribute (Token_Ptr);
1754 end P_Expression_Or_Range_Attribute;
1756 -- Version that allows a non-parenthesized case, conditional, or quantified
1759 function P_Expression_Or_Range_Attribute_If_OK return Node_Id is
1761 if Token = Tok_Case then
1762 return P_Case_Expression;
1764 elsif Token = Tok_If then
1765 return P_Conditional_Expression;
1767 elsif Token = Tok_For then
1768 return P_Quantified_Expression;
1771 return P_Expression_Or_Range_Attribute;
1773 end P_Expression_Or_Range_Attribute_If_OK;
1779 -- This procedure scans both relations and choice relations
1781 -- CHOICE_RELATION ::=
1782 -- SIMPLE_EXPRESSION [RELATIONAL_OPERATOR SIMPLE_EXPRESSION]
1785 -- SIMPLE_EXPRESSION [not] in MEMBERSHIP_CHOICE_LIST
1787 -- MEMBERSHIP_CHOICE_LIST ::=
1788 -- MEMBERSHIP_CHOICE {'|' MEMBERSHIP CHOICE}
1790 -- MEMBERSHIP_CHOICE ::=
1791 -- CHOICE_EXPRESSION | RANGE | SUBTYPE_MARK
1793 -- On return, Expr_Form indicates the categorization of the expression
1795 -- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
1796 -- EF_Simple_Name and the following token is RANGE (range attribute case).
1798 -- Error recovery: cannot raise Error_Resync. If an error occurs within an
1799 -- expression, then tokens are scanned until either a non-expression token,
1800 -- a right paren (not matched by a left paren) or a comma, is encountered.
1802 function P_Relation return Node_Id is
1803 Node1, Node2 : Node_Id;
1807 Node1 := P_Simple_Expression;
1809 if Token not in Token_Class_Relop then
1813 -- Here we have a relational operator following. If so then scan it
1814 -- out. Note that the assignment symbol := is treated as a relational
1815 -- operator to improve the error recovery when it is misused for =.
1816 -- P_Relational_Operator also parses the IN and NOT IN operations.
1819 Node2 := New_Op_Node (P_Relational_Operator, Optok);
1820 Set_Left_Opnd (Node2, Node1);
1822 -- Case of IN or NOT IN
1824 if Prev_Token = Tok_In then
1825 P_Membership_Test (Node2);
1827 -- Case of relational operator (= /= < <= > >=)
1830 Set_Right_Opnd (Node2, P_Simple_Expression);
1833 Expr_Form := EF_Non_Simple;
1835 if Token in Token_Class_Relop then
1836 Error_Msg_SC ("unexpected relational operator");
1843 -- If any error occurs, then scan to the next expression terminator symbol
1844 -- or comma or right paren at the outer (i.e. current) parentheses level.
1845 -- The flags are set to indicate a normal simple expression.
1848 when Error_Resync =>
1850 Expr_Form := EF_Simple;
1854 ----------------------------
1855 -- 4.4 Simple Expression --
1856 ----------------------------
1858 -- SIMPLE_EXPRESSION ::=
1859 -- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
1861 -- On return, Expr_Form indicates the categorization of the expression
1863 -- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
1864 -- EF_Simple_Name and the following token is RANGE (range attribute case).
1866 -- Error recovery: cannot raise Error_Resync. If an error occurs within an
1867 -- expression, then tokens are scanned until either a non-expression token,
1868 -- a right paren (not matched by a left paren) or a comma, is encountered.
1870 -- Note: P_Simple_Expression is called only internally by higher level
1871 -- expression routines. In cases in the grammar where a simple expression
1872 -- is required, the approach is to scan an expression, and then post an
1873 -- appropriate error message if the expression obtained is not simple. This
1874 -- gives better error recovery and treatment.
1876 function P_Simple_Expression return Node_Id is
1877 Scan_State : Saved_Scan_State;
1880 Tokptr : Source_Ptr;
1883 -- Check for cases starting with a name. There are two reasons for
1884 -- special casing. First speed things up by catching a common case
1885 -- without going through several routine layers. Second the caller must
1886 -- be informed via Expr_Form when the simple expression is a name.
1888 if Token in Token_Class_Name then
1891 -- Deal with apostrophe cases
1893 if Token = Tok_Apostrophe then
1894 Save_Scan_State (Scan_State); -- at apostrophe
1895 Scan; -- past apostrophe
1897 -- If qualified expression, scan it out and fall through
1899 if Token = Tok_Left_Paren then
1900 Node1 := P_Qualified_Expression (Node1);
1901 Expr_Form := EF_Simple;
1903 -- If range attribute, then we return with Token pointing to the
1904 -- apostrophe. Note: avoid the normal error check on exit. We
1905 -- know that the expression really is complete in this case!
1907 else -- Token = Tok_Range then
1908 Restore_Scan_State (Scan_State); -- to apostrophe
1909 Expr_Form := EF_Simple_Name;
1914 -- If an expression terminator follows, the previous processing
1915 -- completely scanned out the expression (a common case), and
1916 -- left Expr_Form set appropriately for returning to our caller.
1918 if Token in Token_Class_Sterm then
1921 -- If we do not have an expression terminator, then complete the
1922 -- scan of a simple expression. This code duplicates the code
1923 -- found in P_Term and P_Factor.
1926 if Token = Tok_Double_Asterisk then
1928 Style.Check_Exponentiation_Operator;
1931 Node2 := New_Op_Node (N_Op_Expon, Token_Ptr);
1933 Set_Left_Opnd (Node2, Node1);
1934 Set_Right_Opnd (Node2, P_Primary);
1939 exit when Token not in Token_Class_Mulop;
1940 Tokptr := Token_Ptr;
1941 Node2 := New_Op_Node (P_Multiplying_Operator, Tokptr);
1944 Style.Check_Binary_Operator;
1947 Scan; -- past operator
1948 Set_Left_Opnd (Node2, Node1);
1949 Set_Right_Opnd (Node2, P_Factor);
1954 exit when Token not in Token_Class_Binary_Addop;
1955 Tokptr := Token_Ptr;
1956 Node2 := New_Op_Node (P_Binary_Adding_Operator, Tokptr);
1959 Style.Check_Binary_Operator;
1962 Scan; -- past operator
1963 Set_Left_Opnd (Node2, Node1);
1964 Set_Right_Opnd (Node2, P_Term);
1968 Expr_Form := EF_Simple;
1971 -- Cases where simple expression does not start with a name
1974 -- Scan initial sign and initial Term
1976 if Token in Token_Class_Unary_Addop then
1977 Tokptr := Token_Ptr;
1978 Node1 := New_Op_Node (P_Unary_Adding_Operator, Tokptr);
1981 Style.Check_Unary_Plus_Or_Minus;
1984 Scan; -- past operator
1985 Set_Right_Opnd (Node1, P_Term);
1990 -- In the following, we special-case a sequence of concatenations of
1991 -- string literals, such as "aaa" & "bbb" & ... & "ccc", with nothing
1992 -- else mixed in. For such a sequence, we return a tree representing
1993 -- "" & "aaabbb...ccc" (a single concatenation). This is done only if
1994 -- the number of concatenations is large. If semantic analysis
1995 -- resolves the "&" to a predefined one, then this folding gives the
1996 -- right answer. Otherwise, semantic analysis will complain about a
1997 -- capacity-exceeded error. The purpose of this trick is to avoid
1998 -- creating a deeply nested tree, which would cause deep recursion
1999 -- during semantics, causing stack overflow. This way, we can handle
2000 -- enormous concatenations in the normal case of predefined "&". We
2001 -- first build up the normal tree, and then rewrite it if
2005 Num_Concats_Threshold : constant Positive := 1000;
2006 -- Arbitrary threshold value to enable optimization
2008 First_Node : constant Node_Id := Node1;
2009 Is_Strlit_Concat : Boolean;
2010 -- True iff we've parsed a sequence of concatenations of string
2011 -- literals, with nothing else mixed in.
2013 Num_Concats : Natural;
2014 -- Number of "&" operators if Is_Strlit_Concat is True
2018 Nkind (Node1) = N_String_Literal
2019 and then Token = Tok_Ampersand;
2022 -- Scan out sequence of terms separated by binary adding operators
2025 exit when Token not in Token_Class_Binary_Addop;
2026 Tokptr := Token_Ptr;
2027 Node2 := New_Op_Node (P_Binary_Adding_Operator, Tokptr);
2028 Scan; -- past operator
2029 Set_Left_Opnd (Node2, Node1);
2031 Set_Right_Opnd (Node2, Node1);
2033 -- Check if we're still concatenating string literals
2037 and then Nkind (Node2) = N_Op_Concat
2038 and then Nkind (Node1) = N_String_Literal;
2040 if Is_Strlit_Concat then
2041 Num_Concats := Num_Concats + 1;
2047 -- If we have an enormous series of concatenations of string
2048 -- literals, rewrite as explained above. The Is_Folded_In_Parser
2049 -- flag tells semantic analysis that if the "&" is not predefined,
2050 -- the folded value is wrong.
2053 and then Num_Concats >= Num_Concats_Threshold
2056 Empty_String_Val : String_Id;
2059 Strlit_Concat_Val : String_Id;
2060 -- Contains the folded value (which will be correct if the
2061 -- "&" operators are the predefined ones).
2064 -- For walking up the tree
2067 -- Folded node to replace Node1
2069 Loc : constant Source_Ptr := Sloc (First_Node);
2072 -- Walk up the tree starting at the leftmost string literal
2073 -- (First_Node), building up the Strlit_Concat_Val as we
2074 -- go. Note that we do not use recursion here -- the whole
2075 -- point is to avoid recursively walking that enormous tree.
2078 Store_String_Chars (Strval (First_Node));
2080 Cur_Node := Parent (First_Node);
2081 while Present (Cur_Node) loop
2082 pragma Assert (Nkind (Cur_Node) = N_Op_Concat and then
2083 Nkind (Right_Opnd (Cur_Node)) = N_String_Literal);
2085 Store_String_Chars (Strval (Right_Opnd (Cur_Node)));
2086 Cur_Node := Parent (Cur_Node);
2089 Strlit_Concat_Val := End_String;
2091 -- Create new folded node, and rewrite result with a concat-
2092 -- enation of an empty string literal and the folded node.
2095 Empty_String_Val := End_String;
2097 Make_Op_Concat (Loc,
2098 Make_String_Literal (Loc, Empty_String_Val),
2099 Make_String_Literal (Loc, Strlit_Concat_Val,
2100 Is_Folded_In_Parser => True));
2101 Rewrite (Node1, New_Node);
2106 -- All done, we clearly do not have name or numeric literal so this
2107 -- is a case of a simple expression which is some other possibility.
2109 Expr_Form := EF_Simple;
2112 -- Come here at end of simple expression, where we do a couple of
2113 -- special checks to improve error recovery.
2115 -- Special test to improve error recovery. If the current token
2116 -- is a period, then someone is trying to do selection on something
2117 -- that is not a name, e.g. a qualified expression.
2119 if Token = Tok_Dot then
2120 Error_Msg_SC ("prefix for selection is not a name");
2122 -- If qualified expression, comment and continue, otherwise something
2123 -- is pretty nasty so do an Error_Resync call.
2125 if Ada_Version < Ada_2012
2126 and then Nkind (Node1) = N_Qualified_Expression
2128 Error_Msg_SC ("\would be legal in Ada 2012 mode");
2134 -- Special test to improve error recovery: If the current token is
2135 -- not the first token on a line (as determined by checking the
2136 -- previous token position with the start of the current line),
2137 -- then we insist that we have an appropriate terminating token.
2138 -- Consider the following two examples:
2140 -- 1) if A nad B then ...
2145 -- In the first example, we would like to issue a binary operator
2146 -- expected message and resynchronize to the then. In the second
2147 -- example, we do not want to issue a binary operator message, so
2148 -- that instead we will get the missing semicolon message. This
2149 -- distinction is of course a heuristic which does not always work,
2150 -- but in practice it is quite effective.
2152 -- Note: the one case in which we do not go through this circuit is
2153 -- when we have scanned a range attribute and want to return with
2154 -- Token pointing to the apostrophe. The apostrophe is not normally
2155 -- an expression terminator, and is not in Token_Class_Sterm, but
2156 -- in this special case we know that the expression is complete.
2158 if not Token_Is_At_Start_Of_Line
2159 and then Token not in Token_Class_Sterm
2161 -- Normally the right error message is indeed that we expected a
2162 -- binary operator, but in the case of being between a right and left
2163 -- paren, e.g. in an aggregate, a more likely error is missing comma.
2165 if Prev_Token = Tok_Right_Paren and then Token = Tok_Left_Paren then
2168 Error_Msg_AP ("binary operator expected");
2177 -- If any error occurs, then scan to next expression terminator symbol
2178 -- or comma, right paren or vertical bar at the outer (i.e. current) paren
2179 -- level. Expr_Form is set to indicate a normal simple expression.
2182 when Error_Resync =>
2184 Expr_Form := EF_Simple;
2186 end P_Simple_Expression;
2188 -----------------------------------------------
2189 -- 4.4 Simple Expression or Range Attribute --
2190 -----------------------------------------------
2192 -- SIMPLE_EXPRESSION ::=
2193 -- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
2195 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
2197 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
2199 -- Error recovery: cannot raise Error_Resync
2201 function P_Simple_Expression_Or_Range_Attribute return Node_Id is
2203 Attr_Node : Node_Id;
2206 -- We don't just want to roar ahead and call P_Simple_Expression
2207 -- here, since we want to handle the case of a parenthesized range
2208 -- attribute cleanly.
2210 if Token = Tok_Left_Paren then
2212 Lptr : constant Source_Ptr := Token_Ptr;
2213 Scan_State : Saved_Scan_State;
2216 Save_Scan_State (Scan_State);
2217 Scan; -- past left paren
2218 Sexpr := P_Simple_Expression;
2220 if Token = Tok_Apostrophe then
2221 Attr_Node := P_Range_Attribute_Reference (Sexpr);
2222 Expr_Form := EF_Range_Attr;
2224 if Token = Tok_Right_Paren then
2225 Scan; -- scan past right paren if present
2228 Error_Msg ("parentheses not allowed for range attribute", Lptr);
2233 Restore_Scan_State (Scan_State);
2237 -- Here after dealing with parenthesized range attribute
2239 Sexpr := P_Simple_Expression;
2241 if Token = Tok_Apostrophe then
2242 Attr_Node := P_Range_Attribute_Reference (Sexpr);
2243 Expr_Form := EF_Range_Attr;
2249 end P_Simple_Expression_Or_Range_Attribute;
2255 -- TERM ::= FACTOR {MULTIPLYING_OPERATOR FACTOR}
2257 -- Error recovery: can raise Error_Resync
2259 function P_Term return Node_Id is
2260 Node1, Node2 : Node_Id;
2261 Tokptr : Source_Ptr;
2267 exit when Token not in Token_Class_Mulop;
2268 Tokptr := Token_Ptr;
2269 Node2 := New_Op_Node (P_Multiplying_Operator, Tokptr);
2270 Scan; -- past operator
2271 Set_Left_Opnd (Node2, Node1);
2272 Set_Right_Opnd (Node2, P_Factor);
2283 -- FACTOR ::= PRIMARY [** PRIMARY] | abs PRIMARY | not PRIMARY
2285 -- Error recovery: can raise Error_Resync
2287 function P_Factor return Node_Id is
2292 if Token = Tok_Abs then
2293 Node1 := New_Op_Node (N_Op_Abs, Token_Ptr);
2296 Style.Check_Abs_Not;
2300 Set_Right_Opnd (Node1, P_Primary);
2303 elsif Token = Tok_Not then
2304 Node1 := New_Op_Node (N_Op_Not, Token_Ptr);
2307 Style.Check_Abs_Not;
2311 Set_Right_Opnd (Node1, P_Primary);
2317 if Token = Tok_Double_Asterisk then
2318 Node2 := New_Op_Node (N_Op_Expon, Token_Ptr);
2320 Set_Left_Opnd (Node2, Node1);
2321 Set_Right_Opnd (Node2, P_Primary);
2334 -- NUMERIC_LITERAL | null
2335 -- | STRING_LITERAL | AGGREGATE
2336 -- | NAME | QUALIFIED_EXPRESSION
2337 -- | ALLOCATOR | (EXPRESSION) | QUANTIFIED_EXPRESSION
2339 -- Error recovery: can raise Error_Resync
2341 function P_Primary return Node_Id is
2342 Scan_State : Saved_Scan_State;
2346 -- The loop runs more than once only if misplaced pragmas are found
2351 -- Name token can start a name, call or qualified expression, all
2352 -- of which are acceptable possibilities for primary. Note also
2353 -- that string literal is included in name (as operator symbol)
2354 -- and type conversion is included in name (as indexed component).
2356 when Tok_Char_Literal | Tok_Operator_Symbol | Tok_Identifier =>
2359 -- All done unless apostrophe follows
2361 if Token /= Tok_Apostrophe then
2364 -- Apostrophe following means that we have either just parsed
2365 -- the subtype mark of a qualified expression, or the prefix
2366 -- or a range attribute.
2368 else -- Token = Tok_Apostrophe
2369 Save_Scan_State (Scan_State); -- at apostrophe
2370 Scan; -- past apostrophe
2372 -- If range attribute, then this is always an error, since
2373 -- the only legitimate case (where the scanned expression is
2374 -- a qualified simple name) is handled at the level of the
2375 -- Simple_Expression processing. This case corresponds to a
2376 -- usage such as 3 + A'Range, which is always illegal.
2378 if Token = Tok_Range then
2379 Restore_Scan_State (Scan_State); -- to apostrophe
2380 Bad_Range_Attribute (Token_Ptr);
2383 -- If left paren, then we have a qualified expression.
2384 -- Note that P_Name guarantees that in this case, where
2385 -- Token = Tok_Apostrophe on return, the only two possible
2386 -- tokens following the apostrophe are left paren and
2387 -- RANGE, so we know we have a left paren here.
2389 else -- Token = Tok_Left_Paren
2390 return P_Qualified_Expression (Node1);
2395 -- Numeric or string literal
2397 when Tok_Integer_Literal |
2399 Tok_String_Literal =>
2401 Node1 := Token_Node;
2402 Scan; -- past number
2405 -- Left paren, starts aggregate or parenthesized expression
2407 when Tok_Left_Paren =>
2409 Expr : constant Node_Id := P_Aggregate_Or_Paren_Expr;
2412 if Nkind (Expr) = N_Attribute_Reference
2413 and then Attribute_Name (Expr) = Name_Range
2415 Bad_Range_Attribute (Sloc (Expr));
2430 return New_Node (N_Null, Prev_Token_Ptr);
2432 -- Pragma, not allowed here, so just skip past it
2435 P_Pragmas_Misplaced;
2437 -- Deal with IF (possible unparenthesized conditional expression)
2441 -- If this looks like a real if, defined as an IF appearing at
2442 -- the start of a new line, then we consider we have a missing
2445 if Token_Is_At_Start_Of_Line then
2446 Error_Msg_AP ("missing operand");
2449 -- If this looks like a conditional expression, then treat it
2450 -- that way with an error message.
2452 elsif Ada_Version >= Ada_2012 then
2454 ("conditional expression must be parenthesized");
2455 return P_Conditional_Expression;
2457 -- Otherwise treat as misused identifier
2460 return P_Identifier;
2463 -- Deal with CASE (possible unparenthesized case expression)
2467 -- If this looks like a real case, defined as a CASE appearing
2468 -- the start of a new line, then we consider we have a missing
2471 if Token_Is_At_Start_Of_Line then
2472 Error_Msg_AP ("missing operand");
2475 -- If this looks like a case expression, then treat it that way
2476 -- with an error message.
2478 elsif Ada_Version >= Ada_2012 then
2479 Error_Msg_SC ("case expression must be parenthesized");
2480 return P_Case_Expression;
2482 -- Otherwise treat as misused identifier
2485 return P_Identifier;
2488 -- For [all | some] indicates a quantified expression
2492 if Token_Is_At_Start_Of_Line then
2493 Error_Msg_AP ("misplaced loop");
2496 elsif Ada_Version >= Ada_2012 then
2497 Error_Msg_SC ("quantified expression must be parenthesized");
2498 return P_Quantified_Expression;
2502 -- Otherwise treat as misused identifier
2504 return P_Identifier;
2507 -- Anything else is illegal as the first token of a primary, but
2508 -- we test for a reserved identifier so that it is treated nicely
2511 if Is_Reserved_Identifier then
2512 return P_Identifier;
2514 elsif Prev_Token = Tok_Comma then
2515 Error_Msg_SP -- CODEFIX
2516 ("|extra "","" ignored");
2520 Error_Msg_AP ("missing operand");
2528 -------------------------------
2529 -- 4.4 Quantified_Expression --
2530 -------------------------------
2532 -- QUANTIFIED_EXPRESSION ::=
2533 -- for QUANTIFIER LOOP_PARAMETER_SPECIFICATION => PREDICATE |
2534 -- for QUANTIFIER ITERATOR_SPECIFICATION => PREDICATE
2536 function P_Quantified_Expression return Node_Id is
2543 Node1 := New_Node (N_Quantified_Expression, Prev_Token_Ptr);
2545 if Token = Tok_All then
2546 Set_All_Present (Node1);
2548 -- We treat Some as a non-reserved keyword, so it appears to the scanner
2549 -- as an identifier. If Some is made into a reserved word, the check
2550 -- below is against Tok_Some.
2552 elsif Token /= Tok_Identifier
2553 or else Chars (Token_Node) /= Name_Some
2555 Error_Msg_AP ("missing quantifier");
2560 I_Spec := P_Loop_Parameter_Specification;
2562 if Nkind (I_Spec) = N_Loop_Parameter_Specification then
2563 Set_Loop_Parameter_Specification (Node1, I_Spec);
2565 Set_Iterator_Specification (Node1, I_Spec);
2568 if Token = Tok_Arrow then
2570 Set_Condition (Node1, P_Expression);
2573 Error_Msg_AP ("missing arrow");
2576 end P_Quantified_Expression;
2578 ---------------------------
2579 -- 4.5 Logical Operator --
2580 ---------------------------
2582 -- LOGICAL_OPERATOR ::= and | or | xor
2584 -- Note: AND THEN and OR ELSE are also treated as logical operators
2585 -- by the parser (even though they are not operators semantically)
2587 -- The value returned is the appropriate Node_Kind code for the operator
2588 -- On return, Token points to the token following the scanned operator.
2590 -- The caller has checked that the first token is a legitimate logical
2591 -- operator token (i.e. is either XOR, AND, OR).
2593 -- Error recovery: cannot raise Error_Resync
2595 function P_Logical_Operator return Node_Kind is
2597 if Token = Tok_And then
2599 Style.Check_Binary_Operator;
2604 if Token = Tok_Then then
2611 elsif Token = Tok_Or then
2613 Style.Check_Binary_Operator;
2618 if Token = Tok_Else then
2625 else -- Token = Tok_Xor
2627 Style.Check_Binary_Operator;
2633 end P_Logical_Operator;
2635 ------------------------------
2636 -- 4.5 Relational Operator --
2637 ------------------------------
2639 -- RELATIONAL_OPERATOR ::= = | /= | < | <= | > | >=
2641 -- The value returned is the appropriate Node_Kind code for the operator.
2642 -- On return, Token points to the operator token, NOT past it.
2644 -- The caller has checked that the first token is a legitimate relational
2645 -- operator token (i.e. is one of the operator tokens listed above).
2647 -- Error recovery: cannot raise Error_Resync
2649 function P_Relational_Operator return Node_Kind is
2650 Op_Kind : Node_Kind;
2651 Relop_Node : constant array (Token_Class_Relop) of Node_Kind :=
2652 (Tok_Less => N_Op_Lt,
2653 Tok_Equal => N_Op_Eq,
2654 Tok_Greater => N_Op_Gt,
2655 Tok_Not_Equal => N_Op_Ne,
2656 Tok_Greater_Equal => N_Op_Ge,
2657 Tok_Less_Equal => N_Op_Le,
2659 Tok_Not => N_Not_In,
2660 Tok_Box => N_Op_Ne);
2663 if Token = Tok_Box then
2664 Error_Msg_SC -- CODEFIX
2665 ("|""'<'>"" should be ""/=""");
2668 Op_Kind := Relop_Node (Token);
2671 Style.Check_Binary_Operator;
2674 Scan; -- past operator token
2676 if Prev_Token = Tok_Not then
2681 end P_Relational_Operator;
2683 ---------------------------------
2684 -- 4.5 Binary Adding Operator --
2685 ---------------------------------
2687 -- BINARY_ADDING_OPERATOR ::= + | - | &
2689 -- The value returned is the appropriate Node_Kind code for the operator.
2690 -- On return, Token points to the operator token (NOT past it).
2692 -- The caller has checked that the first token is a legitimate adding
2693 -- operator token (i.e. is one of the operator tokens listed above).
2695 -- Error recovery: cannot raise Error_Resync
2697 function P_Binary_Adding_Operator return Node_Kind is
2698 Addop_Node : constant array (Token_Class_Binary_Addop) of Node_Kind :=
2699 (Tok_Ampersand => N_Op_Concat,
2700 Tok_Minus => N_Op_Subtract,
2701 Tok_Plus => N_Op_Add);
2703 return Addop_Node (Token);
2704 end P_Binary_Adding_Operator;
2706 --------------------------------
2707 -- 4.5 Unary Adding Operator --
2708 --------------------------------
2710 -- UNARY_ADDING_OPERATOR ::= + | -
2712 -- The value returned is the appropriate Node_Kind code for the operator.
2713 -- On return, Token points to the operator token (NOT past it).
2715 -- The caller has checked that the first token is a legitimate adding
2716 -- operator token (i.e. is one of the operator tokens listed above).
2718 -- Error recovery: cannot raise Error_Resync
2720 function P_Unary_Adding_Operator return Node_Kind is
2721 Addop_Node : constant array (Token_Class_Unary_Addop) of Node_Kind :=
2722 (Tok_Minus => N_Op_Minus,
2723 Tok_Plus => N_Op_Plus);
2725 return Addop_Node (Token);
2726 end P_Unary_Adding_Operator;
2728 -------------------------------
2729 -- 4.5 Multiplying Operator --
2730 -------------------------------
2732 -- MULTIPLYING_OPERATOR ::= * | / | mod | rem
2734 -- The value returned is the appropriate Node_Kind code for the operator.
2735 -- On return, Token points to the operator token (NOT past it).
2737 -- The caller has checked that the first token is a legitimate multiplying
2738 -- operator token (i.e. is one of the operator tokens listed above).
2740 -- Error recovery: cannot raise Error_Resync
2742 function P_Multiplying_Operator return Node_Kind is
2743 Mulop_Node : constant array (Token_Class_Mulop) of Node_Kind :=
2744 (Tok_Asterisk => N_Op_Multiply,
2745 Tok_Mod => N_Op_Mod,
2746 Tok_Rem => N_Op_Rem,
2747 Tok_Slash => N_Op_Divide);
2749 return Mulop_Node (Token);
2750 end P_Multiplying_Operator;
2752 --------------------------------------
2753 -- 4.5 Highest Precedence Operator --
2754 --------------------------------------
2756 -- Parsed by P_Factor (4.4)
2758 -- Note: this rule is not in fact used by the grammar at any point!
2760 --------------------------
2761 -- 4.6 Type Conversion --
2762 --------------------------
2764 -- Parsed by P_Primary as a Name (4.1)
2766 -------------------------------
2767 -- 4.7 Qualified Expression --
2768 -------------------------------
2770 -- QUALIFIED_EXPRESSION ::=
2771 -- SUBTYPE_MARK ' (EXPRESSION) | SUBTYPE_MARK ' AGGREGATE
2773 -- The caller has scanned the name which is the Subtype_Mark parameter
2774 -- and scanned past the single quote following the subtype mark. The
2775 -- caller has not checked that this name is in fact appropriate for
2776 -- a subtype mark name (i.e. it is a selected component or identifier).
2778 -- Error_Recovery: cannot raise Error_Resync
2780 function P_Qualified_Expression (Subtype_Mark : Node_Id) return Node_Id is
2781 Qual_Node : Node_Id;
2783 Qual_Node := New_Node (N_Qualified_Expression, Prev_Token_Ptr);
2784 Set_Subtype_Mark (Qual_Node, Check_Subtype_Mark (Subtype_Mark));
2785 Set_Expression (Qual_Node, P_Aggregate_Or_Paren_Expr);
2787 end P_Qualified_Expression;
2789 --------------------
2791 --------------------
2794 -- new [NULL_EXCLUSION] SUBTYPE_INDICATION | new QUALIFIED_EXPRESSION
2796 -- The caller has checked that the initial token is NEW
2798 -- Error recovery: can raise Error_Resync
2800 function P_Allocator return Node_Id is
2801 Alloc_Node : Node_Id;
2802 Type_Node : Node_Id;
2803 Null_Exclusion_Present : Boolean;
2806 Alloc_Node := New_Node (N_Allocator, Token_Ptr);
2809 -- Scan Null_Exclusion if present (Ada 2005 (AI-231))
2811 Null_Exclusion_Present := P_Null_Exclusion;
2812 Set_Null_Exclusion_Present (Alloc_Node, Null_Exclusion_Present);
2813 Type_Node := P_Subtype_Mark_Resync;
2815 if Token = Tok_Apostrophe then
2816 Scan; -- past apostrophe
2817 Set_Expression (Alloc_Node, P_Qualified_Expression (Type_Node));
2821 P_Subtype_Indication (Type_Node, Null_Exclusion_Present));
2827 -----------------------
2828 -- P_Case_Expression --
2829 -----------------------
2831 function P_Case_Expression return Node_Id is
2832 Loc : constant Source_Ptr := Token_Ptr;
2833 Case_Node : Node_Id;
2834 Save_State : Saved_Scan_State;
2837 if Ada_Version < Ada_2012 then
2838 Error_Msg_SC ("|case expression is an Ada 2012 feature");
2839 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2844 Make_Case_Expression (Loc,
2845 Expression => P_Expression_No_Right_Paren,
2846 Alternatives => New_List);
2849 -- We now have scanned out CASE expression IS, scan alternatives
2853 Append_To (Alternatives (Case_Node), P_Case_Expression_Alternative);
2855 -- Missing comma if WHEN (more alternatives present)
2857 if Token = Tok_When then
2860 -- If comma/WHEN, skip comma and we have another alternative
2862 elsif Token = Tok_Comma then
2863 Save_Scan_State (Save_State);
2866 if Token /= Tok_When then
2867 Restore_Scan_State (Save_State);
2871 -- If no comma or WHEN, definitely done
2878 -- If we have an END CASE, diagnose as not needed
2880 if Token = Tok_End then
2881 Error_Msg_SC ("`END CASE` not allowed at end of case expression");
2884 if Token = Tok_Case then
2889 -- Return the Case_Expression node
2892 end P_Case_Expression;
2894 -----------------------------------
2895 -- P_Case_Expression_Alternative --
2896 -----------------------------------
2898 -- CASE_STATEMENT_ALTERNATIVE ::=
2899 -- when DISCRETE_CHOICE_LIST =>
2902 -- The caller has checked that and scanned past the initial WHEN token
2903 -- Error recovery: can raise Error_Resync
2905 function P_Case_Expression_Alternative return Node_Id is
2906 Case_Alt_Node : Node_Id;
2908 Case_Alt_Node := New_Node (N_Case_Expression_Alternative, Token_Ptr);
2909 Set_Discrete_Choices (Case_Alt_Node, P_Discrete_Choice_List);
2911 Set_Expression (Case_Alt_Node, P_Expression);
2912 return Case_Alt_Node;
2913 end P_Case_Expression_Alternative;
2915 ------------------------------
2916 -- P_Conditional_Expression --
2917 ------------------------------
2919 function P_Conditional_Expression return Node_Id is
2920 Exprs : constant List_Id := New_List;
2921 Loc : constant Source_Ptr := Token_Ptr;
2923 State : Saved_Scan_State;
2926 Inside_Conditional_Expression := Inside_Conditional_Expression + 1;
2928 if Token = Tok_If and then Ada_Version < Ada_2012 then
2929 Error_Msg_SC ("|conditional expression is an Ada 2012 feature");
2930 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2933 Scan; -- past IF or ELSIF
2934 Append_To (Exprs, P_Condition);
2936 Append_To (Exprs, P_Expression);
2938 -- We now have scanned out IF expr THEN expr
2940 -- Check for common error of semicolon before the ELSE
2942 if Token = Tok_Semicolon then
2943 Save_Scan_State (State);
2944 Scan; -- past semicolon
2946 if Token = Tok_Else or else Token = Tok_Elsif then
2947 Error_Msg_SP -- CODEFIX
2948 ("|extra "";"" ignored");
2951 Restore_Scan_State (State);
2955 -- Scan out ELSIF sequence if present
2957 if Token = Tok_Elsif then
2958 Expr := P_Conditional_Expression;
2959 Set_Is_Elsif (Expr);
2960 Append_To (Exprs, Expr);
2962 -- Scan out ELSE phrase if present
2964 elsif Token = Tok_Else then
2966 -- Scan out ELSE expression
2969 Append_To (Exprs, P_Expression);
2971 -- Two expression case (implied True, filled in during semantics)
2977 -- If we have an END IF, diagnose as not needed
2979 if Token = Tok_End then
2981 ("`END IF` not allowed at end of conditional expression");
2984 if Token = Tok_If then
2989 Inside_Conditional_Expression := Inside_Conditional_Expression - 1;
2991 -- Return the Conditional_Expression node
2994 Make_Conditional_Expression (Loc,
2995 Expressions => Exprs);
2996 end P_Conditional_Expression;
2998 -----------------------
2999 -- P_Membership_Test --
3000 -----------------------
3002 -- MEMBERSHIP_CHOICE_LIST ::= MEMBERHIP_CHOICE {'|' MEMBERSHIP_CHOICE}
3003 -- MEMBERSHIP_CHOICE ::= CHOICE_EXPRESSION | range | subtype_mark
3005 procedure P_Membership_Test (N : Node_Id) is
3006 Alt : constant Node_Id :=
3007 P_Range_Or_Subtype_Mark
3008 (Allow_Simple_Expression => (Ada_Version >= Ada_2012));
3013 if Token = Tok_Vertical_Bar then
3014 if Ada_Version < Ada_2012 then
3015 Error_Msg_SC ("set notation is an Ada 2012 feature");
3016 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
3019 Set_Alternatives (N, New_List (Alt));
3020 Set_Right_Opnd (N, Empty);
3022 -- Loop to accumulate alternatives
3024 while Token = Tok_Vertical_Bar loop
3025 Scan; -- past vertical bar
3028 P_Range_Or_Subtype_Mark (Allow_Simple_Expression => True));
3034 Set_Right_Opnd (N, Alt);
3035 Set_Alternatives (N, No_List);
3037 end P_Membership_Test;