1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 pragma Style_Checks (All_Checks);
27 -- Turn off subprogram body ordering check. Subprograms are in order
28 -- by RM section rather than alphabetical
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
609 if Token = Tok_Arrow then
611 -- This may be an aggregate that is missing a qualification
614 ("context of aggregate must be a qualified expression");
623 Scan; -- past right paren
624 Prefix_Node := Name_Node;
625 Name_Node := New_Node (N_Slice, Sloc (Prefix_Node));
626 Set_Prefix (Name_Node, Prefix_Node);
627 Set_Discrete_Range (Name_Node, Range_Node);
629 -- An operator node is legal as a prefix to other names,
630 -- but not for a slice.
632 if Nkind (Prefix_Node) = N_Operator_Symbol then
633 Error_Msg_N ("illegal prefix for slice", Prefix_Node);
636 -- If we have a name extension, go scan it
638 if Token in Token_Class_Namext then
639 goto Scan_Name_Extension_OK;
641 -- Otherwise return (a slice is a name, but is not a call)
644 Expr_Form := EF_Name;
649 -- In LP_State_Expr, we have scanned one or more expressions, and
650 -- so we have a call or an indexed component which is a name. On
651 -- entry we have the expression just scanned in Expr_Node and
652 -- Arg_List contains the list of expressions encountered so far
655 Append (Expr_Node, Arg_List);
657 if Token = Tok_Arrow then
659 ("expect identifier in parameter association",
663 elsif not Comma_Present then
665 Prefix_Node := Name_Node;
666 Name_Node := New_Node (N_Indexed_Component, Sloc (Prefix_Node));
667 Set_Prefix (Name_Node, Prefix_Node);
668 Set_Expressions (Name_Node, Arg_List);
669 goto Scan_Name_Extension;
672 -- Comma present (and scanned out), test for identifier => case
673 -- Test for identifier => case
675 if Token = Tok_Identifier then
676 Save_Scan_State (Scan_State); -- at Id
679 -- Test for => (allow := as error substitute)
681 if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
682 Restore_Scan_State (Scan_State); -- to Id
685 -- Otherwise it's just an expression after all, so backup
688 Restore_Scan_State (Scan_State); -- to Id
692 -- Here we have an expression after all, so stay in this state
694 Expr_Node := P_Expression_If_OK;
697 -- LP_State_Call corresponds to the situation in which at least
698 -- one instance of Id => Expression has been encountered, so we
699 -- know that we do not have a name, but rather a call. We enter
700 -- it with the scan pointer pointing to the next argument to scan,
701 -- and Arg_List containing the list of arguments scanned so far.
705 -- Test for case of Id => Expression (named parameter)
707 if Token = Tok_Identifier then
708 Save_Scan_State (Scan_State); -- at Id
709 Ident_Node := Token_Node;
712 -- Deal with => (allow := as erroneous substitute)
714 if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
715 Arg_Node := New_Node (N_Parameter_Association, Prev_Token_Ptr);
716 Set_Selector_Name (Arg_Node, Ident_Node);
718 Set_Explicit_Actual_Parameter (Arg_Node, P_Expression);
719 Append (Arg_Node, Arg_List);
721 -- If a comma follows, go back and scan next entry
723 if Comma_Present then
726 -- Otherwise we have the end of a call
729 Prefix_Node := Name_Node;
730 Name_Node := New_Node (N_Function_Call, Sloc (Prefix_Node));
731 Set_Name (Name_Node, Prefix_Node);
732 Set_Parameter_Associations (Name_Node, Arg_List);
735 if Token in Token_Class_Namext then
736 goto Scan_Name_Extension_OK;
738 -- This is a case of a call which cannot be a name
741 Expr_Form := EF_Name;
746 -- Not named parameter: Id started an expression after all
749 Restore_Scan_State (Scan_State); -- to Id
753 -- Here if entry did not start with Id => which means that it
754 -- is a positional parameter, which is not allowed, since we
755 -- have seen at least one named parameter already.
758 ("positional parameter association " &
759 "not allowed after named one");
761 Expr_Node := P_Expression_If_OK;
763 -- Leaving the '>' in an association is not unusual, so suggest
766 if Nkind (Expr_Node) = N_Op_Eq then
767 Error_Msg_N ("\maybe `='>` was intended", Expr_Node);
770 -- We go back to scanning out expressions, so that we do not get
771 -- multiple error messages when several positional parameters
772 -- follow a named parameter.
776 -- End of treatment for name extensions starting with left paren
778 -- End of loop through name extensions
782 -- This function parses a restricted form of Names which are either
783 -- designators, or designators preceded by a sequence of prefixes
784 -- that are direct names.
786 -- Error recovery: cannot raise Error_Resync
788 function P_Function_Name return Node_Id is
789 Designator_Node : Node_Id;
790 Prefix_Node : Node_Id;
791 Selector_Node : Node_Id;
792 Dot_Sloc : Source_Ptr := No_Location;
795 -- Prefix_Node is set to the gathered prefix so far, Empty means that
796 -- no prefix has been scanned. This allows us to build up the result
797 -- in the required right recursive manner.
799 Prefix_Node := Empty;
801 -- Loop through prefixes
804 Designator_Node := Token_Node;
806 if Token not in Token_Class_Desig then
807 return P_Identifier; -- let P_Identifier issue the error message
809 else -- Token in Token_Class_Desig
810 Scan; -- past designator
811 exit when Token /= Tok_Dot;
814 -- Here at a dot, with token just before it in Designator_Node
816 if No (Prefix_Node) then
817 Prefix_Node := Designator_Node;
819 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
820 Set_Prefix (Selector_Node, Prefix_Node);
821 Set_Selector_Name (Selector_Node, Designator_Node);
822 Prefix_Node := Selector_Node;
825 Dot_Sloc := Token_Ptr;
829 -- Fall out of the loop having just scanned a designator
831 if No (Prefix_Node) then
832 return Designator_Node;
834 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
835 Set_Prefix (Selector_Node, Prefix_Node);
836 Set_Selector_Name (Selector_Node, Designator_Node);
837 return Selector_Node;
845 -- This function parses a restricted form of Names which are either
846 -- identifiers, or identifiers preceded by a sequence of prefixes
847 -- that are direct names.
849 -- Error recovery: cannot raise Error_Resync
851 function P_Qualified_Simple_Name return Node_Id is
852 Designator_Node : Node_Id;
853 Prefix_Node : Node_Id;
854 Selector_Node : Node_Id;
855 Dot_Sloc : Source_Ptr := No_Location;
858 -- Prefix node is set to the gathered prefix so far, Empty means that
859 -- no prefix has been scanned. This allows us to build up the result
860 -- in the required right recursive manner.
862 Prefix_Node := Empty;
864 -- Loop through prefixes
867 Designator_Node := Token_Node;
869 if Token = Tok_Identifier then
870 Scan; -- past identifier
871 exit when Token /= Tok_Dot;
873 elsif Token not in Token_Class_Desig then
874 return P_Identifier; -- let P_Identifier issue the error message
877 Scan; -- past designator
879 if Token /= Tok_Dot then
880 Error_Msg_SP ("identifier expected");
885 -- Here at a dot, with token just before it in Designator_Node
887 if No (Prefix_Node) then
888 Prefix_Node := Designator_Node;
890 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
891 Set_Prefix (Selector_Node, Prefix_Node);
892 Set_Selector_Name (Selector_Node, Designator_Node);
893 Prefix_Node := Selector_Node;
896 Dot_Sloc := Token_Ptr;
900 -- Fall out of the loop having just scanned an identifier
902 if No (Prefix_Node) then
903 return Designator_Node;
905 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
906 Set_Prefix (Selector_Node, Prefix_Node);
907 Set_Selector_Name (Selector_Node, Designator_Node);
908 return Selector_Node;
914 end P_Qualified_Simple_Name;
916 -- This procedure differs from P_Qualified_Simple_Name only in that it
917 -- raises Error_Resync if any error is encountered. It only returns after
918 -- scanning a valid qualified simple name.
920 -- Error recovery: can raise Error_Resync
922 function P_Qualified_Simple_Name_Resync return Node_Id is
923 Designator_Node : Node_Id;
924 Prefix_Node : Node_Id;
925 Selector_Node : Node_Id;
926 Dot_Sloc : Source_Ptr := No_Location;
929 Prefix_Node := Empty;
931 -- Loop through prefixes
934 Designator_Node := Token_Node;
936 if Token = Tok_Identifier then
937 Scan; -- past identifier
938 exit when Token /= Tok_Dot;
940 elsif Token not in Token_Class_Desig then
941 Discard_Junk_Node (P_Identifier); -- to issue the error message
945 Scan; -- past designator
947 if Token /= Tok_Dot then
948 Error_Msg_SP ("identifier expected");
953 -- Here at a dot, with token just before it in Designator_Node
955 if No (Prefix_Node) then
956 Prefix_Node := Designator_Node;
958 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
959 Set_Prefix (Selector_Node, Prefix_Node);
960 Set_Selector_Name (Selector_Node, Designator_Node);
961 Prefix_Node := Selector_Node;
964 Dot_Sloc := Token_Ptr;
968 -- Fall out of the loop having just scanned an identifier
970 if No (Prefix_Node) then
971 return Designator_Node;
973 Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
974 Set_Prefix (Selector_Node, Prefix_Node);
975 Set_Selector_Name (Selector_Node, Designator_Node);
976 return Selector_Node;
978 end P_Qualified_Simple_Name_Resync;
980 ----------------------
981 -- 4.1 Direct_Name --
982 ----------------------
984 -- Parsed by P_Name and other functions in section 4.1
990 -- Parsed by P_Name (4.1)
992 -------------------------------
993 -- 4.1 Explicit Dereference --
994 -------------------------------
996 -- Parsed by P_Name (4.1)
998 -------------------------------
999 -- 4.1 Implicit_Dereference --
1000 -------------------------------
1002 -- Parsed by P_Name (4.1)
1004 ----------------------------
1005 -- 4.1 Indexed Component --
1006 ----------------------------
1008 -- Parsed by P_Name (4.1)
1014 -- Parsed by P_Name (4.1)
1016 -----------------------------
1017 -- 4.1 Selected_Component --
1018 -----------------------------
1020 -- Parsed by P_Name (4.1)
1022 ------------------------
1023 -- 4.1 Selector Name --
1024 ------------------------
1026 -- Parsed by P_Name (4.1)
1028 ------------------------------
1029 -- 4.1 Attribute Reference --
1030 ------------------------------
1032 -- Parsed by P_Name (4.1)
1034 -------------------------------
1035 -- 4.1 Attribute Designator --
1036 -------------------------------
1038 -- Parsed by P_Name (4.1)
1040 --------------------------------------
1041 -- 4.1.4 Range Attribute Reference --
1042 --------------------------------------
1044 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
1046 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
1048 -- In the grammar, a RANGE attribute is simply a name, but its use is
1049 -- highly restricted, so in the parser, we do not regard it as a name.
1050 -- Instead, P_Name returns without scanning the 'RANGE part of the
1051 -- attribute, and the caller uses the following function to construct
1052 -- a range attribute in places where it is appropriate.
1054 -- Note that RANGE here is treated essentially as an identifier,
1055 -- rather than a reserved word.
1057 -- The caller has parsed the prefix, i.e. a name, and Token points to
1058 -- the apostrophe. The token after the apostrophe is known to be RANGE
1059 -- at this point. The prefix node becomes the prefix of the attribute.
1061 -- Error_Recovery: Cannot raise Error_Resync
1063 function P_Range_Attribute_Reference
1064 (Prefix_Node : Node_Id)
1067 Attr_Node : Node_Id;
1070 Attr_Node := New_Node (N_Attribute_Reference, Token_Ptr);
1071 Set_Prefix (Attr_Node, Prefix_Node);
1072 Scan; -- past apostrophe
1075 Style.Check_Attribute_Name (True);
1078 Set_Attribute_Name (Attr_Node, Name_Range);
1081 if Token = Tok_Left_Paren then
1082 Scan; -- past left paren
1083 Set_Expressions (Attr_Node, New_List (P_Expression_If_OK));
1088 end P_Range_Attribute_Reference;
1090 ---------------------------------------
1091 -- 4.1.4 Range Attribute Designator --
1092 ---------------------------------------
1094 -- Parsed by P_Range_Attribute_Reference (4.4)
1096 --------------------
1098 --------------------
1100 -- AGGREGATE ::= RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
1102 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3), except in the case where
1103 -- an aggregate is known to be required (code statement, extension
1104 -- aggregate), in which cases this routine performs the necessary check
1105 -- that we have an aggregate rather than a parenthesized expression
1107 -- Error recovery: can raise Error_Resync
1109 function P_Aggregate return Node_Id is
1110 Aggr_Sloc : constant Source_Ptr := Token_Ptr;
1111 Aggr_Node : constant Node_Id := P_Aggregate_Or_Paren_Expr;
1114 if Nkind (Aggr_Node) /= N_Aggregate
1116 Nkind (Aggr_Node) /= N_Extension_Aggregate
1119 ("aggregate may not have single positional component", Aggr_Sloc);
1126 ------------------------------------------------
1127 -- 4.3 Aggregate or Parenthesized Expression --
1128 ------------------------------------------------
1130 -- This procedure parses out either an aggregate or a parenthesized
1131 -- expression (these two constructs are closely related, since a
1132 -- parenthesized expression looks like an aggregate with a single
1133 -- positional component).
1136 -- RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
1138 -- RECORD_AGGREGATE ::= (RECORD_COMPONENT_ASSOCIATION_LIST)
1140 -- RECORD_COMPONENT_ASSOCIATION_LIST ::=
1141 -- RECORD_COMPONENT_ASSOCIATION {, RECORD_COMPONENT_ASSOCIATION}
1144 -- RECORD_COMPONENT_ASSOCIATION ::=
1145 -- [COMPONENT_CHOICE_LIST =>] EXPRESSION
1147 -- COMPONENT_CHOICE_LIST ::=
1148 -- component_SELECTOR_NAME {| component_SELECTOR_NAME}
1151 -- EXTENSION_AGGREGATE ::=
1152 -- (ANCESTOR_PART with RECORD_COMPONENT_ASSOCIATION_LIST)
1154 -- ANCESTOR_PART ::= EXPRESSION | SUBTYPE_MARK
1156 -- ARRAY_AGGREGATE ::=
1157 -- POSITIONAL_ARRAY_AGGREGATE | NAMED_ARRAY_AGGREGATE
1159 -- POSITIONAL_ARRAY_AGGREGATE ::=
1160 -- (EXPRESSION, EXPRESSION {, EXPRESSION})
1161 -- | (EXPRESSION {, EXPRESSION}, others => EXPRESSION)
1162 -- | (EXPRESSION {, EXPRESSION}, others => <>)
1164 -- NAMED_ARRAY_AGGREGATE ::=
1165 -- (ARRAY_COMPONENT_ASSOCIATION {, ARRAY_COMPONENT_ASSOCIATION})
1167 -- PRIMARY ::= (EXPRESSION);
1169 -- Error recovery: can raise Error_Resync
1171 -- Note: POSITIONAL_ARRAY_AGGREGATE rule has been extended to give support
1172 -- to Ada 2005 limited aggregates (AI-287)
1174 function P_Aggregate_Or_Paren_Expr return Node_Id is
1175 Aggregate_Node : Node_Id;
1176 Expr_List : List_Id;
1177 Assoc_List : List_Id;
1178 Expr_Node : Node_Id;
1179 Lparen_Sloc : Source_Ptr;
1180 Scan_State : Saved_Scan_State;
1182 procedure Box_Error;
1183 -- Called if <> is encountered as positional aggregate element. Issues
1184 -- error message and sets Expr_Node to Error.
1190 procedure Box_Error is
1192 if Ada_Version < Ada_2005 then
1193 Error_Msg_SC ("box in aggregate is an Ada 2005 extension");
1196 -- Ada 2005 (AI-287): The box notation is allowed only with named
1197 -- notation because positional notation might be error prone. For
1198 -- example, in "(X, <>, Y, <>)", there is no type associated with
1199 -- the boxes, so you might not be leaving out the components you
1200 -- thought you were leaving out.
1202 Error_Msg_SC ("(Ada 2005) box only allowed with named notation");
1207 -- Start of processing for P_Aggregate_Or_Paren_Expr
1210 Lparen_Sloc := Token_Ptr;
1213 -- Conditional expression case
1215 if Token = Tok_If then
1216 Expr_Node := P_Conditional_Expression;
1220 -- Case expression case
1222 elsif Token = Tok_Case then
1223 Expr_Node := P_Case_Expression;
1227 -- Quantified expression case
1229 elsif Token = Tok_For then
1230 Expr_Node := P_Quantified_Expression;
1234 -- Note: the mechanism used here of rescanning the initial expression
1235 -- is distinctly unpleasant, but it saves a lot of fiddling in scanning
1236 -- out the discrete choice list.
1238 -- Deal with expression and extension aggregate cases first
1240 elsif Token /= Tok_Others then
1241 Save_Scan_State (Scan_State); -- at start of expression
1243 -- Deal with (NULL RECORD) case
1245 if Token = Tok_Null then
1248 if Token = Tok_Record then
1249 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1250 Set_Null_Record_Present (Aggregate_Node, True);
1251 Scan; -- past RECORD
1253 return Aggregate_Node;
1255 Restore_Scan_State (Scan_State); -- to NULL that must be expr
1259 -- Scan expression, handling box appearing as positional argument
1261 if Token = Tok_Box then
1264 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
1267 -- Extension aggregate case
1269 if Token = Tok_With then
1270 if Nkind (Expr_Node) = N_Attribute_Reference
1271 and then Attribute_Name (Expr_Node) = Name_Range
1273 Bad_Range_Attribute (Sloc (Expr_Node));
1277 if Ada_Version = Ada_83 then
1278 Error_Msg_SC ("(Ada 83) extension aggregate not allowed");
1281 Aggregate_Node := New_Node (N_Extension_Aggregate, Lparen_Sloc);
1282 Set_Ancestor_Part (Aggregate_Node, Expr_Node);
1285 -- Deal with WITH NULL RECORD case
1287 if Token = Tok_Null then
1288 Save_Scan_State (Scan_State); -- at NULL
1291 if Token = Tok_Record then
1292 Scan; -- past RECORD
1293 Set_Null_Record_Present (Aggregate_Node, True);
1295 return Aggregate_Node;
1298 Restore_Scan_State (Scan_State); -- to NULL that must be expr
1302 if Token /= Tok_Others then
1303 Save_Scan_State (Scan_State);
1304 Expr_Node := P_Expression;
1311 elsif Token = Tok_Right_Paren or else Token in Token_Class_Eterm then
1312 if Nkind (Expr_Node) = N_Attribute_Reference
1313 and then Attribute_Name (Expr_Node) = Name_Range
1316 ("|parentheses not allowed for range attribute", Lparen_Sloc);
1317 Scan; -- past right paren
1321 -- Bump paren count of expression
1323 if Expr_Node /= Error then
1324 Set_Paren_Count (Expr_Node, Paren_Count (Expr_Node) + 1);
1327 T_Right_Paren; -- past right paren (error message if none)
1330 -- Normal aggregate case
1333 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1339 Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
1343 -- Prepare to scan list of component associations
1345 Expr_List := No_List; -- don't set yet, maybe all named entries
1346 Assoc_List := No_List; -- don't set yet, maybe all positional entries
1348 -- This loop scans through component associations. On entry to the
1349 -- loop, an expression has been scanned at the start of the current
1350 -- association unless initial token was OTHERS, in which case
1351 -- Expr_Node is set to Empty.
1354 -- Deal with others association first. This is a named association
1356 if No (Expr_Node) then
1357 if No (Assoc_List) then
1358 Assoc_List := New_List;
1361 Append (P_Record_Or_Array_Component_Association, Assoc_List);
1363 -- Improper use of WITH
1365 elsif Token = Tok_With then
1366 Error_Msg_SC ("WITH must be preceded by single expression in " &
1367 "extension aggregate");
1370 -- Range attribute can only appear as part of a discrete choice list
1372 elsif Nkind (Expr_Node) = N_Attribute_Reference
1373 and then Attribute_Name (Expr_Node) = Name_Range
1374 and then Token /= Tok_Arrow
1375 and then Token /= Tok_Vertical_Bar
1377 Bad_Range_Attribute (Sloc (Expr_Node));
1380 -- Assume positional case if comma, right paren, or literal or
1381 -- identifier or OTHERS follows (the latter cases are missing
1382 -- comma cases). Also assume positional if a semicolon follows,
1383 -- which can happen if there are missing parens
1385 elsif Token = Tok_Comma
1386 or else Token = Tok_Right_Paren
1387 or else Token = Tok_Others
1388 or else Token in Token_Class_Lit_Or_Name
1389 or else Token = Tok_Semicolon
1391 if Present (Assoc_List) then
1392 Error_Msg_BC -- CODEFIX
1393 ("""='>"" expected (positional association cannot follow " &
1394 "named association)");
1397 if No (Expr_List) then
1398 Expr_List := New_List;
1401 Append (Expr_Node, Expr_List);
1403 -- Check for aggregate followed by left parent, maybe missing comma
1405 elsif Nkind (Expr_Node) = N_Aggregate
1406 and then Token = Tok_Left_Paren
1410 if No (Expr_List) then
1411 Expr_List := New_List;
1414 Append (Expr_Node, Expr_List);
1416 -- Anything else is assumed to be a named association
1419 Restore_Scan_State (Scan_State); -- to start of expression
1421 if No (Assoc_List) then
1422 Assoc_List := New_List;
1425 Append (P_Record_Or_Array_Component_Association, Assoc_List);
1428 exit when not Comma_Present;
1430 -- If we are at an expression terminator, something is seriously
1431 -- wrong, so let's get out now, before we start eating up stuff
1432 -- that doesn't belong to us!
1434 if Token in Token_Class_Eterm then
1436 -- If Some becomes a keyword, the following is needed to make it
1437 -- acceptable in older versions of Ada.
1440 and then Ada_Version < Ada_2012
1442 Scan_Reserved_Identifier (False);
1445 ("expecting expression or component association");
1450 -- Deal with misused box
1452 if Token = Tok_Box then
1455 -- Otherwise initiate for reentry to top of loop by scanning an
1456 -- initial expression, unless the first token is OTHERS.
1458 elsif Token = Tok_Others then
1462 Save_Scan_State (Scan_State); -- at start of expression
1463 Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
1468 -- All component associations (positional and named) have been scanned
1471 Set_Expressions (Aggregate_Node, Expr_List);
1472 Set_Component_Associations (Aggregate_Node, Assoc_List);
1473 return Aggregate_Node;
1474 end P_Aggregate_Or_Paren_Expr;
1476 ------------------------------------------------
1477 -- 4.3 Record or Array Component Association --
1478 ------------------------------------------------
1480 -- RECORD_COMPONENT_ASSOCIATION ::=
1481 -- [COMPONENT_CHOICE_LIST =>] EXPRESSION
1482 -- | COMPONENT_CHOICE_LIST => <>
1484 -- COMPONENT_CHOICE_LIST =>
1485 -- component_SELECTOR_NAME {| component_SELECTOR_NAME}
1488 -- ARRAY_COMPONENT_ASSOCIATION ::=
1489 -- DISCRETE_CHOICE_LIST => EXPRESSION
1490 -- | DISCRETE_CHOICE_LIST => <>
1492 -- Note: this routine only handles the named cases, including others.
1493 -- Cases where the component choice list is not present have already
1494 -- been handled directly.
1496 -- Error recovery: can raise Error_Resync
1498 -- Note: RECORD_COMPONENT_ASSOCIATION and ARRAY_COMPONENT_ASSOCIATION
1499 -- rules have been extended to give support to Ada 2005 limited
1500 -- aggregates (AI-287)
1502 function P_Record_Or_Array_Component_Association return Node_Id is
1503 Assoc_Node : Node_Id;
1506 Assoc_Node := New_Node (N_Component_Association, Token_Ptr);
1507 Set_Choices (Assoc_Node, P_Discrete_Choice_List);
1508 Set_Sloc (Assoc_Node, Token_Ptr);
1511 if Token = Tok_Box then
1513 -- Ada 2005(AI-287): The box notation is used to indicate the
1514 -- default initialization of aggregate components
1516 if Ada_Version < Ada_2005 then
1518 ("component association with '<'> is an Ada 2005 extension");
1519 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1522 Set_Box_Present (Assoc_Node);
1525 Set_Expression (Assoc_Node, P_Expression);
1529 end P_Record_Or_Array_Component_Association;
1531 -----------------------------
1532 -- 4.3.1 Record Aggregate --
1533 -----------------------------
1535 -- Case of enumeration aggregate is parsed by P_Aggregate (4.3)
1536 -- All other cases are parsed by P_Aggregate_Or_Paren_Expr (4.3)
1538 ----------------------------------------------
1539 -- 4.3.1 Record Component Association List --
1540 ----------------------------------------------
1542 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1544 ----------------------------------
1545 -- 4.3.1 Component Choice List --
1546 ----------------------------------
1548 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1550 --------------------------------
1551 -- 4.3.1 Extension Aggregate --
1552 --------------------------------
1554 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1556 --------------------------
1557 -- 4.3.1 Ancestor Part --
1558 --------------------------
1560 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1562 ----------------------------
1563 -- 4.3.1 Array Aggregate --
1564 ----------------------------
1566 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1568 ---------------------------------------
1569 -- 4.3.1 Positional Array Aggregate --
1570 ---------------------------------------
1572 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1574 ----------------------------------
1575 -- 4.3.1 Named Array Aggregate --
1576 ----------------------------------
1578 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1580 ----------------------------------------
1581 -- 4.3.1 Array Component Association --
1582 ----------------------------------------
1584 -- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
1586 ---------------------
1587 -- 4.4 Expression --
1588 ---------------------
1590 -- This procedure parses EXPRESSION or CHOICE_EXPRESSION
1593 -- RELATION {LOGICAL_OPERATOR RELATION}
1595 -- CHOICE_EXPRESSION ::=
1596 -- CHOICE_RELATION {LOGICAL_OPERATOR CHOICE_RELATION}
1598 -- LOGICAL_OPERATOR ::= and | and then | or | or else | xor
1600 -- On return, Expr_Form indicates the categorization of the expression
1601 -- EF_Range_Attr is not a possible value (if a range attribute is found,
1602 -- an error message is given, and Error is returned).
1604 -- Error recovery: cannot raise Error_Resync
1606 function P_Expression return Node_Id is
1607 Logical_Op : Node_Kind;
1608 Prev_Logical_Op : Node_Kind;
1609 Op_Location : Source_Ptr;
1614 Node1 := P_Relation;
1616 if Token in Token_Class_Logop then
1617 Prev_Logical_Op := N_Empty;
1620 Op_Location := Token_Ptr;
1621 Logical_Op := P_Logical_Operator;
1623 if Prev_Logical_Op /= N_Empty and then
1624 Logical_Op /= Prev_Logical_Op
1627 ("mixed logical operators in expression", Op_Location);
1628 Prev_Logical_Op := N_Empty;
1630 Prev_Logical_Op := Logical_Op;
1634 Node1 := New_Op_Node (Logical_Op, Op_Location);
1635 Set_Left_Opnd (Node1, Node2);
1636 Set_Right_Opnd (Node1, P_Relation);
1637 exit when Token not in Token_Class_Logop;
1640 Expr_Form := EF_Non_Simple;
1643 if Token = Tok_Apostrophe then
1644 Bad_Range_Attribute (Token_Ptr);
1651 -- This function is identical to the normal P_Expression, except that it
1652 -- also permits the appearance of a case, conditional, or quantified
1653 -- expression without the usual surrounding parentheses.
1655 function P_Expression_If_OK return Node_Id is
1657 if Token = Tok_Case then
1658 return P_Case_Expression;
1660 elsif Token = Tok_If then
1661 return P_Conditional_Expression;
1663 elsif Token = Tok_For then
1664 return P_Quantified_Expression;
1667 return P_Expression;
1669 end P_Expression_If_OK;
1671 -- This function is identical to the normal P_Expression, except that it
1672 -- checks that the expression scan did not stop on a right paren. It is
1673 -- called in all contexts where a right parenthesis cannot legitimately
1674 -- follow an expression.
1676 -- Error recovery: can not raise Error_Resync
1678 function P_Expression_No_Right_Paren return Node_Id is
1679 Expr : constant Node_Id := P_Expression;
1681 Ignore (Tok_Right_Paren);
1683 end P_Expression_No_Right_Paren;
1685 ----------------------------------------
1686 -- 4.4 Expression_Or_Range_Attribute --
1687 ----------------------------------------
1690 -- RELATION {and RELATION} | RELATION {and then RELATION}
1691 -- | RELATION {or RELATION} | RELATION {or else RELATION}
1692 -- | RELATION {xor RELATION}
1694 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
1696 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
1698 -- On return, Expr_Form indicates the categorization of the expression
1699 -- and EF_Range_Attr is one of the possibilities.
1701 -- Error recovery: cannot raise Error_Resync
1703 -- In the grammar, a RANGE attribute is simply a name, but its use is
1704 -- highly restricted, so in the parser, we do not regard it as a name.
1705 -- Instead, P_Name returns without scanning the 'RANGE part of the
1706 -- attribute, and P_Expression_Or_Range_Attribute handles the range
1707 -- attribute reference. In the normal case where a range attribute is
1708 -- not allowed, an error message is issued by P_Expression.
1710 function P_Expression_Or_Range_Attribute return Node_Id is
1711 Logical_Op : Node_Kind;
1712 Prev_Logical_Op : Node_Kind;
1713 Op_Location : Source_Ptr;
1716 Attr_Node : Node_Id;
1719 Node1 := P_Relation;
1721 if Token = Tok_Apostrophe then
1722 Attr_Node := P_Range_Attribute_Reference (Node1);
1723 Expr_Form := EF_Range_Attr;
1726 elsif Token in Token_Class_Logop then
1727 Prev_Logical_Op := N_Empty;
1730 Op_Location := Token_Ptr;
1731 Logical_Op := P_Logical_Operator;
1733 if Prev_Logical_Op /= N_Empty and then
1734 Logical_Op /= Prev_Logical_Op
1737 ("mixed logical operators in expression", Op_Location);
1738 Prev_Logical_Op := N_Empty;
1740 Prev_Logical_Op := Logical_Op;
1744 Node1 := New_Op_Node (Logical_Op, Op_Location);
1745 Set_Left_Opnd (Node1, Node2);
1746 Set_Right_Opnd (Node1, P_Relation);
1747 exit when Token not in Token_Class_Logop;
1750 Expr_Form := EF_Non_Simple;
1753 if Token = Tok_Apostrophe then
1754 Bad_Range_Attribute (Token_Ptr);
1759 end P_Expression_Or_Range_Attribute;
1761 -- Version that allows a non-parenthesized case, conditional, or quantified
1764 function P_Expression_Or_Range_Attribute_If_OK return Node_Id is
1766 if Token = Tok_Case then
1767 return P_Case_Expression;
1769 elsif Token = Tok_If then
1770 return P_Conditional_Expression;
1772 elsif Token = Tok_For then
1773 return P_Quantified_Expression;
1776 return P_Expression_Or_Range_Attribute;
1778 end P_Expression_Or_Range_Attribute_If_OK;
1784 -- This procedure scans both relations and choice relations
1786 -- CHOICE_RELATION ::=
1787 -- SIMPLE_EXPRESSION [RELATIONAL_OPERATOR SIMPLE_EXPRESSION]
1790 -- SIMPLE_EXPRESSION [not] in MEMBERSHIP_CHOICE_LIST
1792 -- MEMBERSHIP_CHOICE_LIST ::=
1793 -- MEMBERSHIP_CHOICE {'|' MEMBERSHIP CHOICE}
1795 -- MEMBERSHIP_CHOICE ::=
1796 -- CHOICE_EXPRESSION | RANGE | SUBTYPE_MARK
1798 -- On return, Expr_Form indicates the categorization of the expression
1800 -- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
1801 -- EF_Simple_Name and the following token is RANGE (range attribute case).
1803 -- Error recovery: cannot raise Error_Resync. If an error occurs within an
1804 -- expression, then tokens are scanned until either a non-expression token,
1805 -- a right paren (not matched by a left paren) or a comma, is encountered.
1807 function P_Relation return Node_Id is
1808 Node1, Node2 : Node_Id;
1812 Node1 := P_Simple_Expression;
1814 if Token not in Token_Class_Relop then
1818 -- Here we have a relational operator following. If so then scan it
1819 -- out. Note that the assignment symbol := is treated as a relational
1820 -- operator to improve the error recovery when it is misused for =.
1821 -- P_Relational_Operator also parses the IN and NOT IN operations.
1824 Node2 := New_Op_Node (P_Relational_Operator, Optok);
1825 Set_Left_Opnd (Node2, Node1);
1827 -- Case of IN or NOT IN
1829 if Prev_Token = Tok_In then
1830 P_Membership_Test (Node2);
1832 -- Case of relational operator (= /= < <= > >=)
1835 Set_Right_Opnd (Node2, P_Simple_Expression);
1838 Expr_Form := EF_Non_Simple;
1840 if Token in Token_Class_Relop then
1841 Error_Msg_SC ("unexpected relational operator");
1848 -- If any error occurs, then scan to the next expression terminator symbol
1849 -- or comma or right paren at the outer (i.e. current) parentheses level.
1850 -- The flags are set to indicate a normal simple expression.
1853 when Error_Resync =>
1855 Expr_Form := EF_Simple;
1859 ----------------------------
1860 -- 4.4 Simple Expression --
1861 ----------------------------
1863 -- SIMPLE_EXPRESSION ::=
1864 -- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
1866 -- On return, Expr_Form indicates the categorization of the expression
1868 -- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
1869 -- EF_Simple_Name and the following token is RANGE (range attribute case).
1871 -- Error recovery: cannot raise Error_Resync. If an error occurs within an
1872 -- expression, then tokens are scanned until either a non-expression token,
1873 -- a right paren (not matched by a left paren) or a comma, is encountered.
1875 -- Note: P_Simple_Expression is called only internally by higher level
1876 -- expression routines. In cases in the grammar where a simple expression
1877 -- is required, the approach is to scan an expression, and then post an
1878 -- appropriate error message if the expression obtained is not simple. This
1879 -- gives better error recovery and treatment.
1881 function P_Simple_Expression return Node_Id is
1882 Scan_State : Saved_Scan_State;
1885 Tokptr : Source_Ptr;
1888 -- Check for cases starting with a name. There are two reasons for
1889 -- special casing. First speed things up by catching a common case
1890 -- without going through several routine layers. Second the caller must
1891 -- be informed via Expr_Form when the simple expression is a name.
1893 if Token in Token_Class_Name then
1896 -- Deal with apostrophe cases
1898 if Token = Tok_Apostrophe then
1899 Save_Scan_State (Scan_State); -- at apostrophe
1900 Scan; -- past apostrophe
1902 -- If qualified expression, scan it out and fall through
1904 if Token = Tok_Left_Paren then
1905 Node1 := P_Qualified_Expression (Node1);
1906 Expr_Form := EF_Simple;
1908 -- If range attribute, then we return with Token pointing to the
1909 -- apostrophe. Note: avoid the normal error check on exit. We
1910 -- know that the expression really is complete in this case!
1912 else -- Token = Tok_Range then
1913 Restore_Scan_State (Scan_State); -- to apostrophe
1914 Expr_Form := EF_Simple_Name;
1919 -- If an expression terminator follows, the previous processing
1920 -- completely scanned out the expression (a common case), and
1921 -- left Expr_Form set appropriately for returning to our caller.
1923 if Token in Token_Class_Sterm then
1926 -- If we do not have an expression terminator, then complete the
1927 -- scan of a simple expression. This code duplicates the code
1928 -- found in P_Term and P_Factor.
1931 if Token = Tok_Double_Asterisk then
1933 Style.Check_Exponentiation_Operator;
1936 Node2 := New_Op_Node (N_Op_Expon, Token_Ptr);
1938 Set_Left_Opnd (Node2, Node1);
1939 Set_Right_Opnd (Node2, P_Primary);
1944 exit when Token not in Token_Class_Mulop;
1945 Tokptr := Token_Ptr;
1946 Node2 := New_Op_Node (P_Multiplying_Operator, Tokptr);
1949 Style.Check_Binary_Operator;
1952 Scan; -- past operator
1953 Set_Left_Opnd (Node2, Node1);
1954 Set_Right_Opnd (Node2, P_Factor);
1959 exit when Token not in Token_Class_Binary_Addop;
1960 Tokptr := Token_Ptr;
1961 Node2 := New_Op_Node (P_Binary_Adding_Operator, Tokptr);
1964 Style.Check_Binary_Operator;
1967 Scan; -- past operator
1968 Set_Left_Opnd (Node2, Node1);
1969 Set_Right_Opnd (Node2, P_Term);
1973 Expr_Form := EF_Simple;
1976 -- Cases where simple expression does not start with a name
1979 -- Scan initial sign and initial Term
1981 if Token in Token_Class_Unary_Addop then
1982 Tokptr := Token_Ptr;
1983 Node1 := New_Op_Node (P_Unary_Adding_Operator, Tokptr);
1986 Style.Check_Unary_Plus_Or_Minus;
1989 Scan; -- past operator
1990 Set_Right_Opnd (Node1, P_Term);
1995 -- In the following, we special-case a sequence of concatenations of
1996 -- string literals, such as "aaa" & "bbb" & ... & "ccc", with nothing
1997 -- else mixed in. For such a sequence, we return a tree representing
1998 -- "" & "aaabbb...ccc" (a single concatenation). This is done only if
1999 -- the number of concatenations is large. If semantic analysis
2000 -- resolves the "&" to a predefined one, then this folding gives the
2001 -- right answer. Otherwise, semantic analysis will complain about a
2002 -- capacity-exceeded error. The purpose of this trick is to avoid
2003 -- creating a deeply nested tree, which would cause deep recursion
2004 -- during semantics, causing stack overflow. This way, we can handle
2005 -- enormous concatenations in the normal case of predefined "&". We
2006 -- first build up the normal tree, and then rewrite it if
2010 Num_Concats_Threshold : constant Positive := 1000;
2011 -- Arbitrary threshold value to enable optimization
2013 First_Node : constant Node_Id := Node1;
2014 Is_Strlit_Concat : Boolean;
2015 -- True iff we've parsed a sequence of concatenations of string
2016 -- literals, with nothing else mixed in.
2018 Num_Concats : Natural;
2019 -- Number of "&" operators if Is_Strlit_Concat is True
2023 Nkind (Node1) = N_String_Literal
2024 and then Token = Tok_Ampersand;
2027 -- Scan out sequence of terms separated by binary adding operators
2030 exit when Token not in Token_Class_Binary_Addop;
2031 Tokptr := Token_Ptr;
2032 Node2 := New_Op_Node (P_Binary_Adding_Operator, Tokptr);
2033 Scan; -- past operator
2034 Set_Left_Opnd (Node2, Node1);
2036 Set_Right_Opnd (Node2, Node1);
2038 -- Check if we're still concatenating string literals
2042 and then Nkind (Node2) = N_Op_Concat
2043 and then Nkind (Node1) = N_String_Literal;
2045 if Is_Strlit_Concat then
2046 Num_Concats := Num_Concats + 1;
2052 -- If we have an enormous series of concatenations of string
2053 -- literals, rewrite as explained above. The Is_Folded_In_Parser
2054 -- flag tells semantic analysis that if the "&" is not predefined,
2055 -- the folded value is wrong.
2058 and then Num_Concats >= Num_Concats_Threshold
2061 Empty_String_Val : String_Id;
2064 Strlit_Concat_Val : String_Id;
2065 -- Contains the folded value (which will be correct if the
2066 -- "&" operators are the predefined ones).
2069 -- For walking up the tree
2072 -- Folded node to replace Node1
2074 Loc : constant Source_Ptr := Sloc (First_Node);
2077 -- Walk up the tree starting at the leftmost string literal
2078 -- (First_Node), building up the Strlit_Concat_Val as we
2079 -- go. Note that we do not use recursion here -- the whole
2080 -- point is to avoid recursively walking that enormous tree.
2083 Store_String_Chars (Strval (First_Node));
2085 Cur_Node := Parent (First_Node);
2086 while Present (Cur_Node) loop
2087 pragma Assert (Nkind (Cur_Node) = N_Op_Concat and then
2088 Nkind (Right_Opnd (Cur_Node)) = N_String_Literal);
2090 Store_String_Chars (Strval (Right_Opnd (Cur_Node)));
2091 Cur_Node := Parent (Cur_Node);
2094 Strlit_Concat_Val := End_String;
2096 -- Create new folded node, and rewrite result with a concat-
2097 -- enation of an empty string literal and the folded node.
2100 Empty_String_Val := End_String;
2102 Make_Op_Concat (Loc,
2103 Make_String_Literal (Loc, Empty_String_Val),
2104 Make_String_Literal (Loc, Strlit_Concat_Val,
2105 Is_Folded_In_Parser => True));
2106 Rewrite (Node1, New_Node);
2111 -- All done, we clearly do not have name or numeric literal so this
2112 -- is a case of a simple expression which is some other possibility.
2114 Expr_Form := EF_Simple;
2117 -- Come here at end of simple expression, where we do a couple of
2118 -- special checks to improve error recovery.
2120 -- Special test to improve error recovery. If the current token
2121 -- is a period, then someone is trying to do selection on something
2122 -- that is not a name, e.g. a qualified expression.
2124 if Token = Tok_Dot then
2125 Error_Msg_SC ("prefix for selection is not a name");
2127 -- If qualified expression, comment and continue, otherwise something
2128 -- is pretty nasty so do an Error_Resync call.
2130 if Ada_Version < Ada_2012
2131 and then Nkind (Node1) = N_Qualified_Expression
2133 Error_Msg_SC ("\would be legal in Ada 2012 mode");
2139 -- Special test to improve error recovery: If the current token is
2140 -- not the first token on a line (as determined by checking the
2141 -- previous token position with the start of the current line),
2142 -- then we insist that we have an appropriate terminating token.
2143 -- Consider the following two examples:
2145 -- 1) if A nad B then ...
2150 -- In the first example, we would like to issue a binary operator
2151 -- expected message and resynchronize to the then. In the second
2152 -- example, we do not want to issue a binary operator message, so
2153 -- that instead we will get the missing semicolon message. This
2154 -- distinction is of course a heuristic which does not always work,
2155 -- but in practice it is quite effective.
2157 -- Note: the one case in which we do not go through this circuit is
2158 -- when we have scanned a range attribute and want to return with
2159 -- Token pointing to the apostrophe. The apostrophe is not normally
2160 -- an expression terminator, and is not in Token_Class_Sterm, but
2161 -- in this special case we know that the expression is complete.
2163 if not Token_Is_At_Start_Of_Line
2164 and then Token not in Token_Class_Sterm
2166 -- Normally the right error message is indeed that we expected a
2167 -- binary operator, but in the case of being between a right and left
2168 -- paren, e.g. in an aggregate, a more likely error is missing comma.
2170 if Prev_Token = Tok_Right_Paren and then Token = Tok_Left_Paren then
2173 Error_Msg_AP ("binary operator expected");
2182 -- If any error occurs, then scan to next expression terminator symbol
2183 -- or comma, right paren or vertical bar at the outer (i.e. current) paren
2184 -- level. Expr_Form is set to indicate a normal simple expression.
2187 when Error_Resync =>
2189 Expr_Form := EF_Simple;
2191 end P_Simple_Expression;
2193 -----------------------------------------------
2194 -- 4.4 Simple Expression or Range Attribute --
2195 -----------------------------------------------
2197 -- SIMPLE_EXPRESSION ::=
2198 -- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
2200 -- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
2202 -- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
2204 -- Error recovery: cannot raise Error_Resync
2206 function P_Simple_Expression_Or_Range_Attribute return Node_Id is
2208 Attr_Node : Node_Id;
2211 -- We don't just want to roar ahead and call P_Simple_Expression
2212 -- here, since we want to handle the case of a parenthesized range
2213 -- attribute cleanly.
2215 if Token = Tok_Left_Paren then
2217 Lptr : constant Source_Ptr := Token_Ptr;
2218 Scan_State : Saved_Scan_State;
2221 Save_Scan_State (Scan_State);
2222 Scan; -- past left paren
2223 Sexpr := P_Simple_Expression;
2225 if Token = Tok_Apostrophe then
2226 Attr_Node := P_Range_Attribute_Reference (Sexpr);
2227 Expr_Form := EF_Range_Attr;
2229 if Token = Tok_Right_Paren then
2230 Scan; -- scan past right paren if present
2233 Error_Msg ("parentheses not allowed for range attribute", Lptr);
2238 Restore_Scan_State (Scan_State);
2242 -- Here after dealing with parenthesized range attribute
2244 Sexpr := P_Simple_Expression;
2246 if Token = Tok_Apostrophe then
2247 Attr_Node := P_Range_Attribute_Reference (Sexpr);
2248 Expr_Form := EF_Range_Attr;
2254 end P_Simple_Expression_Or_Range_Attribute;
2260 -- TERM ::= FACTOR {MULTIPLYING_OPERATOR FACTOR}
2262 -- Error recovery: can raise Error_Resync
2264 function P_Term return Node_Id is
2265 Node1, Node2 : Node_Id;
2266 Tokptr : Source_Ptr;
2272 exit when Token not in Token_Class_Mulop;
2273 Tokptr := Token_Ptr;
2274 Node2 := New_Op_Node (P_Multiplying_Operator, Tokptr);
2275 Scan; -- past operator
2276 Set_Left_Opnd (Node2, Node1);
2277 Set_Right_Opnd (Node2, P_Factor);
2288 -- FACTOR ::= PRIMARY [** PRIMARY] | abs PRIMARY | not PRIMARY
2290 -- Error recovery: can raise Error_Resync
2292 function P_Factor return Node_Id is
2297 if Token = Tok_Abs then
2298 Node1 := New_Op_Node (N_Op_Abs, Token_Ptr);
2301 Style.Check_Abs_Not;
2305 Set_Right_Opnd (Node1, P_Primary);
2308 elsif Token = Tok_Not then
2309 Node1 := New_Op_Node (N_Op_Not, Token_Ptr);
2312 Style.Check_Abs_Not;
2316 Set_Right_Opnd (Node1, P_Primary);
2322 if Token = Tok_Double_Asterisk then
2323 Node2 := New_Op_Node (N_Op_Expon, Token_Ptr);
2325 Set_Left_Opnd (Node2, Node1);
2326 Set_Right_Opnd (Node2, P_Primary);
2339 -- NUMERIC_LITERAL | null
2340 -- | STRING_LITERAL | AGGREGATE
2341 -- | NAME | QUALIFIED_EXPRESSION
2342 -- | ALLOCATOR | (EXPRESSION) | QUANTIFIED_EXPRESSION
2344 -- Error recovery: can raise Error_Resync
2346 function P_Primary return Node_Id is
2347 Scan_State : Saved_Scan_State;
2351 -- The loop runs more than once only if misplaced pragmas are found
2356 -- Name token can start a name, call or qualified expression, all
2357 -- of which are acceptable possibilities for primary. Note also
2358 -- that string literal is included in name (as operator symbol)
2359 -- and type conversion is included in name (as indexed component).
2361 when Tok_Char_Literal | Tok_Operator_Symbol | Tok_Identifier =>
2364 -- All done unless apostrophe follows
2366 if Token /= Tok_Apostrophe then
2369 -- Apostrophe following means that we have either just parsed
2370 -- the subtype mark of a qualified expression, or the prefix
2371 -- or a range attribute.
2373 else -- Token = Tok_Apostrophe
2374 Save_Scan_State (Scan_State); -- at apostrophe
2375 Scan; -- past apostrophe
2377 -- If range attribute, then this is always an error, since
2378 -- the only legitimate case (where the scanned expression is
2379 -- a qualified simple name) is handled at the level of the
2380 -- Simple_Expression processing. This case corresponds to a
2381 -- usage such as 3 + A'Range, which is always illegal.
2383 if Token = Tok_Range then
2384 Restore_Scan_State (Scan_State); -- to apostrophe
2385 Bad_Range_Attribute (Token_Ptr);
2388 -- If left paren, then we have a qualified expression.
2389 -- Note that P_Name guarantees that in this case, where
2390 -- Token = Tok_Apostrophe on return, the only two possible
2391 -- tokens following the apostrophe are left paren and
2392 -- RANGE, so we know we have a left paren here.
2394 else -- Token = Tok_Left_Paren
2395 return P_Qualified_Expression (Node1);
2400 -- Numeric or string literal
2402 when Tok_Integer_Literal |
2404 Tok_String_Literal =>
2406 Node1 := Token_Node;
2407 Scan; -- past number
2410 -- Left paren, starts aggregate or parenthesized expression
2412 when Tok_Left_Paren =>
2414 Expr : constant Node_Id := P_Aggregate_Or_Paren_Expr;
2417 if Nkind (Expr) = N_Attribute_Reference
2418 and then Attribute_Name (Expr) = Name_Range
2420 Bad_Range_Attribute (Sloc (Expr));
2435 return New_Node (N_Null, Prev_Token_Ptr);
2437 -- Pragma, not allowed here, so just skip past it
2440 P_Pragmas_Misplaced;
2442 -- Deal with IF (possible unparenthesized conditional expression)
2446 -- If this looks like a real if, defined as an IF appearing at
2447 -- the start of a new line, then we consider we have a missing
2450 if Token_Is_At_Start_Of_Line then
2451 Error_Msg_AP ("missing operand");
2454 -- If this looks like a conditional expression, then treat it
2455 -- that way with an error message.
2457 elsif Ada_Version >= Ada_2012 then
2459 ("conditional expression must be parenthesized");
2460 return P_Conditional_Expression;
2462 -- Otherwise treat as misused identifier
2465 return P_Identifier;
2468 -- Deal with CASE (possible unparenthesized case expression)
2472 -- If this looks like a real case, defined as a CASE appearing
2473 -- the start of a new line, then we consider we have a missing
2476 if Token_Is_At_Start_Of_Line then
2477 Error_Msg_AP ("missing operand");
2480 -- If this looks like a case expression, then treat it that way
2481 -- with an error message.
2483 elsif Ada_Version >= Ada_2012 then
2484 Error_Msg_SC ("case expression must be parenthesized");
2485 return P_Case_Expression;
2487 -- Otherwise treat as misused identifier
2490 return P_Identifier;
2493 -- For [all | some] indicates a quantified expression
2497 if Token_Is_At_Start_Of_Line then
2498 Error_Msg_AP ("misplaced loop");
2501 elsif Ada_Version >= Ada_2012 then
2502 Error_Msg_SC ("quantified expression must be parenthesized");
2503 return P_Quantified_Expression;
2507 -- Otherwise treat as misused identifier
2509 return P_Identifier;
2512 -- Anything else is illegal as the first token of a primary, but
2513 -- we test for a reserved identifier so that it is treated nicely
2516 if Is_Reserved_Identifier then
2517 return P_Identifier;
2519 elsif Prev_Token = Tok_Comma then
2520 Error_Msg_SP -- CODEFIX
2521 ("|extra "","" ignored");
2525 Error_Msg_AP ("missing operand");
2533 -------------------------------
2534 -- 4.4 Quantified_Expression --
2535 -------------------------------
2537 -- QUANTIFIED_EXPRESSION ::=
2538 -- for QUANTIFIER LOOP_PARAMETER_SPECIFICATION => PREDICATE |
2539 -- for QUANTIFIER ITERATOR_SPECIFICATION => PREDICATE
2541 function P_Quantified_Expression return Node_Id is
2548 Node1 := New_Node (N_Quantified_Expression, Prev_Token_Ptr);
2550 if Token = Tok_All then
2551 Set_All_Present (Node1);
2553 -- We treat Some as a non-reserved keyword, so it appears to the scanner
2554 -- as an identifier. If Some is made into a reserved word, the check
2555 -- below is against Tok_Some.
2557 elsif Token /= Tok_Identifier
2558 or else Chars (Token_Node) /= Name_Some
2560 Error_Msg_AP ("missing quantifier");
2565 I_Spec := P_Loop_Parameter_Specification;
2567 if Nkind (I_Spec) = N_Loop_Parameter_Specification then
2568 Set_Loop_Parameter_Specification (Node1, I_Spec);
2570 Set_Iterator_Specification (Node1, I_Spec);
2573 if Token = Tok_Arrow then
2575 Set_Condition (Node1, P_Expression);
2578 Error_Msg_AP ("missing arrow");
2581 end P_Quantified_Expression;
2583 ---------------------------
2584 -- 4.5 Logical Operator --
2585 ---------------------------
2587 -- LOGICAL_OPERATOR ::= and | or | xor
2589 -- Note: AND THEN and OR ELSE are also treated as logical operators
2590 -- by the parser (even though they are not operators semantically)
2592 -- The value returned is the appropriate Node_Kind code for the operator
2593 -- On return, Token points to the token following the scanned operator.
2595 -- The caller has checked that the first token is a legitimate logical
2596 -- operator token (i.e. is either XOR, AND, OR).
2598 -- Error recovery: cannot raise Error_Resync
2600 function P_Logical_Operator return Node_Kind is
2602 if Token = Tok_And then
2604 Style.Check_Binary_Operator;
2609 if Token = Tok_Then then
2616 elsif Token = Tok_Or then
2618 Style.Check_Binary_Operator;
2623 if Token = Tok_Else then
2630 else -- Token = Tok_Xor
2632 Style.Check_Binary_Operator;
2638 end P_Logical_Operator;
2640 ------------------------------
2641 -- 4.5 Relational Operator --
2642 ------------------------------
2644 -- RELATIONAL_OPERATOR ::= = | /= | < | <= | > | >=
2646 -- The value returned is the appropriate Node_Kind code for the operator.
2647 -- On return, Token points to the operator token, NOT past it.
2649 -- The caller has checked that the first token is a legitimate relational
2650 -- operator token (i.e. is one of the operator tokens listed above).
2652 -- Error recovery: cannot raise Error_Resync
2654 function P_Relational_Operator return Node_Kind is
2655 Op_Kind : Node_Kind;
2656 Relop_Node : constant array (Token_Class_Relop) of Node_Kind :=
2657 (Tok_Less => N_Op_Lt,
2658 Tok_Equal => N_Op_Eq,
2659 Tok_Greater => N_Op_Gt,
2660 Tok_Not_Equal => N_Op_Ne,
2661 Tok_Greater_Equal => N_Op_Ge,
2662 Tok_Less_Equal => N_Op_Le,
2664 Tok_Not => N_Not_In,
2665 Tok_Box => N_Op_Ne);
2668 if Token = Tok_Box then
2669 Error_Msg_SC -- CODEFIX
2670 ("|""'<'>"" should be ""/=""");
2673 Op_Kind := Relop_Node (Token);
2676 Style.Check_Binary_Operator;
2679 Scan; -- past operator token
2681 if Prev_Token = Tok_Not then
2686 end P_Relational_Operator;
2688 ---------------------------------
2689 -- 4.5 Binary Adding Operator --
2690 ---------------------------------
2692 -- BINARY_ADDING_OPERATOR ::= + | - | &
2694 -- The value returned is the appropriate Node_Kind code for the operator.
2695 -- On return, Token points to the operator token (NOT past it).
2697 -- The caller has checked that the first token is a legitimate adding
2698 -- operator token (i.e. is one of the operator tokens listed above).
2700 -- Error recovery: cannot raise Error_Resync
2702 function P_Binary_Adding_Operator return Node_Kind is
2703 Addop_Node : constant array (Token_Class_Binary_Addop) of Node_Kind :=
2704 (Tok_Ampersand => N_Op_Concat,
2705 Tok_Minus => N_Op_Subtract,
2706 Tok_Plus => N_Op_Add);
2708 return Addop_Node (Token);
2709 end P_Binary_Adding_Operator;
2711 --------------------------------
2712 -- 4.5 Unary Adding Operator --
2713 --------------------------------
2715 -- UNARY_ADDING_OPERATOR ::= + | -
2717 -- The value returned is the appropriate Node_Kind code for the operator.
2718 -- On return, Token points to the operator token (NOT past it).
2720 -- The caller has checked that the first token is a legitimate adding
2721 -- operator token (i.e. is one of the operator tokens listed above).
2723 -- Error recovery: cannot raise Error_Resync
2725 function P_Unary_Adding_Operator return Node_Kind is
2726 Addop_Node : constant array (Token_Class_Unary_Addop) of Node_Kind :=
2727 (Tok_Minus => N_Op_Minus,
2728 Tok_Plus => N_Op_Plus);
2730 return Addop_Node (Token);
2731 end P_Unary_Adding_Operator;
2733 -------------------------------
2734 -- 4.5 Multiplying Operator --
2735 -------------------------------
2737 -- MULTIPLYING_OPERATOR ::= * | / | mod | rem
2739 -- The value returned is the appropriate Node_Kind code for the operator.
2740 -- On return, Token points to the operator token (NOT past it).
2742 -- The caller has checked that the first token is a legitimate multiplying
2743 -- operator token (i.e. is one of the operator tokens listed above).
2745 -- Error recovery: cannot raise Error_Resync
2747 function P_Multiplying_Operator return Node_Kind is
2748 Mulop_Node : constant array (Token_Class_Mulop) of Node_Kind :=
2749 (Tok_Asterisk => N_Op_Multiply,
2750 Tok_Mod => N_Op_Mod,
2751 Tok_Rem => N_Op_Rem,
2752 Tok_Slash => N_Op_Divide);
2754 return Mulop_Node (Token);
2755 end P_Multiplying_Operator;
2757 --------------------------------------
2758 -- 4.5 Highest Precedence Operator --
2759 --------------------------------------
2761 -- Parsed by P_Factor (4.4)
2763 -- Note: this rule is not in fact used by the grammar at any point!
2765 --------------------------
2766 -- 4.6 Type Conversion --
2767 --------------------------
2769 -- Parsed by P_Primary as a Name (4.1)
2771 -------------------------------
2772 -- 4.7 Qualified Expression --
2773 -------------------------------
2775 -- QUALIFIED_EXPRESSION ::=
2776 -- SUBTYPE_MARK ' (EXPRESSION) | SUBTYPE_MARK ' AGGREGATE
2778 -- The caller has scanned the name which is the Subtype_Mark parameter
2779 -- and scanned past the single quote following the subtype mark. The
2780 -- caller has not checked that this name is in fact appropriate for
2781 -- a subtype mark name (i.e. it is a selected component or identifier).
2783 -- Error_Recovery: cannot raise Error_Resync
2785 function P_Qualified_Expression (Subtype_Mark : Node_Id) return Node_Id is
2786 Qual_Node : Node_Id;
2788 Qual_Node := New_Node (N_Qualified_Expression, Prev_Token_Ptr);
2789 Set_Subtype_Mark (Qual_Node, Check_Subtype_Mark (Subtype_Mark));
2790 Set_Expression (Qual_Node, P_Aggregate_Or_Paren_Expr);
2792 end P_Qualified_Expression;
2794 --------------------
2796 --------------------
2799 -- new [NULL_EXCLUSION] SUBTYPE_INDICATION | new QUALIFIED_EXPRESSION
2801 -- The caller has checked that the initial token is NEW
2803 -- Error recovery: can raise Error_Resync
2805 function P_Allocator return Node_Id is
2806 Alloc_Node : Node_Id;
2807 Type_Node : Node_Id;
2808 Null_Exclusion_Present : Boolean;
2811 Alloc_Node := New_Node (N_Allocator, Token_Ptr);
2814 -- Scan Null_Exclusion if present (Ada 2005 (AI-231))
2816 Null_Exclusion_Present := P_Null_Exclusion;
2817 Set_Null_Exclusion_Present (Alloc_Node, Null_Exclusion_Present);
2818 Type_Node := P_Subtype_Mark_Resync;
2820 if Token = Tok_Apostrophe then
2821 Scan; -- past apostrophe
2822 Set_Expression (Alloc_Node, P_Qualified_Expression (Type_Node));
2826 P_Subtype_Indication (Type_Node, Null_Exclusion_Present));
2832 -----------------------
2833 -- P_Case_Expression --
2834 -----------------------
2836 function P_Case_Expression return Node_Id is
2837 Loc : constant Source_Ptr := Token_Ptr;
2838 Case_Node : Node_Id;
2839 Save_State : Saved_Scan_State;
2842 if Ada_Version < Ada_2012 then
2843 Error_Msg_SC ("|case expression is an Ada 2012 feature");
2844 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2849 Make_Case_Expression (Loc,
2850 Expression => P_Expression_No_Right_Paren,
2851 Alternatives => New_List);
2854 -- We now have scanned out CASE expression IS, scan alternatives
2858 Append_To (Alternatives (Case_Node), P_Case_Expression_Alternative);
2860 -- Missing comma if WHEN (more alternatives present)
2862 if Token = Tok_When then
2865 -- If comma/WHEN, skip comma and we have another alternative
2867 elsif Token = Tok_Comma then
2868 Save_Scan_State (Save_State);
2871 if Token /= Tok_When then
2872 Restore_Scan_State (Save_State);
2876 -- If no comma or WHEN, definitely done
2883 -- If we have an END CASE, diagnose as not needed
2885 if Token = Tok_End then
2886 Error_Msg_SC ("`END CASE` not allowed at end of case expression");
2889 if Token = Tok_Case then
2894 -- Return the Case_Expression node
2897 end P_Case_Expression;
2899 -----------------------------------
2900 -- P_Case_Expression_Alternative --
2901 -----------------------------------
2903 -- CASE_STATEMENT_ALTERNATIVE ::=
2904 -- when DISCRETE_CHOICE_LIST =>
2907 -- The caller has checked that and scanned past the initial WHEN token
2908 -- Error recovery: can raise Error_Resync
2910 function P_Case_Expression_Alternative return Node_Id is
2911 Case_Alt_Node : Node_Id;
2913 Case_Alt_Node := New_Node (N_Case_Expression_Alternative, Token_Ptr);
2914 Set_Discrete_Choices (Case_Alt_Node, P_Discrete_Choice_List);
2916 Set_Expression (Case_Alt_Node, P_Expression);
2917 return Case_Alt_Node;
2918 end P_Case_Expression_Alternative;
2920 ------------------------------
2921 -- P_Conditional_Expression --
2922 ------------------------------
2924 function P_Conditional_Expression return Node_Id is
2925 Exprs : constant List_Id := New_List;
2926 Loc : constant Source_Ptr := Token_Ptr;
2928 State : Saved_Scan_State;
2931 Inside_Conditional_Expression := Inside_Conditional_Expression + 1;
2933 if Token = Tok_If and then Ada_Version < Ada_2012 then
2934 Error_Msg_SC ("|conditional expression is an Ada 2012 feature");
2935 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
2938 Scan; -- past IF or ELSIF
2939 Append_To (Exprs, P_Condition);
2941 Append_To (Exprs, P_Expression);
2943 -- We now have scanned out IF expr THEN expr
2945 -- Check for common error of semicolon before the ELSE
2947 if Token = Tok_Semicolon then
2948 Save_Scan_State (State);
2949 Scan; -- past semicolon
2951 if Token = Tok_Else or else Token = Tok_Elsif then
2952 Error_Msg_SP -- CODEFIX
2953 ("|extra "";"" ignored");
2956 Restore_Scan_State (State);
2960 -- Scan out ELSIF sequence if present
2962 if Token = Tok_Elsif then
2963 Expr := P_Conditional_Expression;
2964 Set_Is_Elsif (Expr);
2965 Append_To (Exprs, Expr);
2967 -- Scan out ELSE phrase if present
2969 elsif Token = Tok_Else then
2971 -- Scan out ELSE expression
2974 Append_To (Exprs, P_Expression);
2976 -- Two expression case (implied True, filled in during semantics)
2982 -- If we have an END IF, diagnose as not needed
2984 if Token = Tok_End then
2986 ("`END IF` not allowed at end of conditional expression");
2989 if Token = Tok_If then
2994 Inside_Conditional_Expression := Inside_Conditional_Expression - 1;
2996 -- Return the Conditional_Expression node
2999 Make_Conditional_Expression (Loc,
3000 Expressions => Exprs);
3001 end P_Conditional_Expression;
3003 -----------------------
3004 -- P_Membership_Test --
3005 -----------------------
3007 -- MEMBERSHIP_CHOICE_LIST ::= MEMBERHIP_CHOICE {'|' MEMBERSHIP_CHOICE}
3008 -- MEMBERSHIP_CHOICE ::= CHOICE_EXPRESSION | range | subtype_mark
3010 procedure P_Membership_Test (N : Node_Id) is
3011 Alt : constant Node_Id :=
3012 P_Range_Or_Subtype_Mark
3013 (Allow_Simple_Expression => (Ada_Version >= Ada_2012));
3018 if Token = Tok_Vertical_Bar then
3019 if Ada_Version < Ada_2012 then
3020 Error_Msg_SC ("set notation is an Ada 2012 feature");
3021 Error_Msg_SC ("\|unit must be compiled with -gnat2012 switch");
3024 Set_Alternatives (N, New_List (Alt));
3025 Set_Right_Opnd (N, Empty);
3027 -- Loop to accumulate alternatives
3029 while Token = Tok_Vertical_Bar loop
3030 Scan; -- past vertical bar
3033 P_Range_Or_Subtype_Mark (Allow_Simple_Expression => True));
3039 Set_Right_Opnd (N, Alt);
3040 Set_Alternatives (N, No_List);
3042 end P_Membership_Test;