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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- P A R . C H 3 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
pragma Style_Checks (All_Checks);
-- Turn off subprogram body ordering check. Subprograms are in order
-- by RM section rather than alphabetical
with Sinfo.CN; use Sinfo.CN;
separate (Par)
package body Ch3 is
-----------------------
-- Local Subprograms --
-----------------------
function P_Component_List return Node_Id;
function P_Defining_Character_Literal return Node_Id;
function P_Delta_Constraint return Node_Id;
function P_Derived_Type_Def_Or_Private_Ext_Decl return Node_Id;
function P_Digits_Constraint return Node_Id;
function P_Discriminant_Association return Node_Id;
function P_Enumeration_Literal_Specification return Node_Id;
function P_Enumeration_Type_Definition return Node_Id;
function P_Fixed_Point_Definition return Node_Id;
function P_Floating_Point_Definition return Node_Id;
function P_Index_Or_Discriminant_Constraint return Node_Id;
function P_Real_Range_Specification_Opt return Node_Id;
function P_Subtype_Declaration return Node_Id;
function P_Type_Declaration return Node_Id;
function P_Modular_Type_Definition return Node_Id;
function P_Variant return Node_Id;
function P_Variant_Part return Node_Id;
procedure P_Declarative_Items
(Decls : List_Id;
Done : out Boolean;
In_Spec : Boolean);
-- Scans out a single declarative item, or, in the case of a declaration
-- with a list of identifiers, a list of declarations, one for each of
-- the identifiers in the list. The declaration or declarations scanned
-- are appended to the given list. Done indicates whether or not there
-- may be additional declarative items to scan. If Done is True, then
-- a decision has been made that there are no more items to scan. If
-- Done is False, then there may be additional declarations to scan.
-- In_Spec is true if we are scanning a package declaration, and is used
-- to generate an appropriate message if a statement is encountered in
-- such a context.
procedure P_Identifier_Declarations
(Decls : List_Id;
Done : out Boolean;
In_Spec : Boolean);
-- Scans out a set of declarations for an identifier or list of
-- identifiers, and appends them to the given list. The parameters have
-- the same significance as for P_Declarative_Items.
procedure Statement_When_Declaration_Expected
(Decls : List_Id;
Done : out Boolean;
In_Spec : Boolean);
-- Called when a statement is found at a point where a declaration was
-- expected. The parameters are as described for P_Declarative_Items.
procedure Set_Declaration_Expected;
-- Posts a "declaration expected" error messages at the start of the
-- current token, and if this is the first such message issued, saves
-- the message id in Missing_Begin_Msg, for possible later replacement.
-------------------
-- Init_Expr_Opt --
-------------------
function Init_Expr_Opt (P : Boolean := False) return Node_Id is
begin
-- For colon, assume it means := unless it is at the end of
-- a line, in which case guess that it means a semicolon.
if Token = Tok_Colon then
if Token_Is_At_End_Of_Line then
T_Semicolon;
return Empty;
end if;
-- Here if := or something that we will take as equivalent
elsif Token = Tok_Colon_Equal
or else Token = Tok_Equal
or else Token = Tok_Is
then
null;
-- Another possibility. If we have a literal followed by a semicolon,
-- we assume that we have a missing colon-equal.
elsif Token in Token_Class_Literal then
declare
Scan_State : Saved_Scan_State;
begin
Save_Scan_State (Scan_State);
Scan; -- past literal or identifier
if Token = Tok_Semicolon then
Restore_Scan_State (Scan_State);
else
Restore_Scan_State (Scan_State);
return Empty;
end if;
end;
-- Otherwise we definitely have no initialization expression
else
return Empty;
end if;
-- Merge here if we have an initialization expression
T_Colon_Equal;
if P then
return P_Expression;
else
return P_Expression_No_Right_Paren;
end if;
end Init_Expr_Opt;
----------------------------
-- 3.1 Basic Declaration --
----------------------------
-- Parsed by P_Basic_Declarative_Items (3.9)
------------------------------
-- 3.1 Defining Identifier --
------------------------------
-- DEFINING_IDENTIFIER ::= IDENTIFIER
-- Error recovery: can raise Error_Resync
function P_Defining_Identifier (C : Id_Check := None) return Node_Id is
Ident_Node : Node_Id;
begin
-- Scan out the identifier. Note that this code is essentially identical
-- to P_Identifier, except that in the call to Scan_Reserved_Identifier
-- we set Force_Msg to True, since we want at least one message for each
-- separate declaration (but not use) of a reserved identifier.
if Token = Tok_Identifier then
null;
-- If we have a reserved identifier, manufacture an identifier with
-- a corresponding name after posting an appropriate error message
elsif Is_Reserved_Identifier (C) then
Scan_Reserved_Identifier (Force_Msg => True);
-- Otherwise we have junk that cannot be interpreted as an identifier
else
T_Identifier; -- to give message
raise Error_Resync;
end if;
Ident_Node := Token_Node;
Scan; -- past the reserved identifier
if Ident_Node /= Error then
Change_Identifier_To_Defining_Identifier (Ident_Node);
end if;
return Ident_Node;
end P_Defining_Identifier;
-----------------------------
-- 3.2.1 Type Declaration --
-----------------------------
-- TYPE_DECLARATION ::=
-- FULL_TYPE_DECLARATION
-- | INCOMPLETE_TYPE_DECLARATION
-- | PRIVATE_TYPE_DECLARATION
-- | PRIVATE_EXTENSION_DECLARATION
-- FULL_TYPE_DECLARATION ::=
-- type DEFINING_IDENTIFIER [KNOWN_DISCRIMINANT_PART] is TYPE_DEFINITION;
-- | CONCURRENT_TYPE_DECLARATION
-- INCOMPLETE_TYPE_DECLARATION ::=
-- type DEFINING_IDENTIFIER [DISCRIMINANT_PART];
-- PRIVATE_TYPE_DECLARATION ::=
-- type DEFINING_IDENTIFIER [DISCRIMINANT_PART]
-- is [abstract] [tagged] [limited] private;
-- PRIVATE_EXTENSION_DECLARATION ::=
-- type DEFINING_IDENTIFIER [DISCRIMINANT_PART] is
-- [abstract] new ancestor_SUBTYPE_INDICATION with private;
-- TYPE_DEFINITION ::=
-- ENUMERATION_TYPE_DEFINITION | INTEGER_TYPE_DEFINITION
-- | REAL_TYPE_DEFINITION | ARRAY_TYPE_DEFINITION
-- | RECORD_TYPE_DEFINITION | ACCESS_TYPE_DEFINITION
-- | DERIVED_TYPE_DEFINITION
-- INTEGER_TYPE_DEFINITION ::=
-- SIGNED_INTEGER_TYPE_DEFINITION
-- MODULAR_TYPE_DEFINITION
-- Error recovery: can raise Error_Resync
-- Note: The processing for full type declaration, incomplete type
-- declaration, private type declaration and type definition is
-- included in this function. The processing for concurrent type
-- declarations is NOT here, but rather in chapter 9 (i.e. this
-- function handles only declarations starting with TYPE).
function P_Type_Declaration return Node_Id is
Type_Loc : Source_Ptr;
Type_Start_Col : Column_Number;
Ident_Node : Node_Id;
Decl_Node : Node_Id;
Discr_List : List_Id;
Unknown_Dis : Boolean;
Discr_Sloc : Source_Ptr;
Abstract_Present : Boolean;
Abstract_Loc : Source_Ptr;
End_Labl : Node_Id;
Typedef_Node : Node_Id;
-- Normally holds type definition, except in the case of a private
-- extension declaration, in which case it holds the declaration itself
begin
Type_Loc := Token_Ptr;
Type_Start_Col := Start_Column;
T_Type;
Ident_Node := P_Defining_Identifier (C_Is);
Discr_Sloc := Token_Ptr;
if P_Unknown_Discriminant_Part_Opt then
Unknown_Dis := True;
Discr_List := No_List;
else
Unknown_Dis := False;
Discr_List := P_Known_Discriminant_Part_Opt;
end if;
-- Incomplete type declaration. We complete the processing for this
-- case here and return the resulting incomplete type declaration node
if Token = Tok_Semicolon then
Scan; -- past ;
Decl_Node := New_Node (N_Incomplete_Type_Declaration, Type_Loc);
Set_Defining_Identifier (Decl_Node, Ident_Node);
Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
Set_Discriminant_Specifications (Decl_Node, Discr_List);
return Decl_Node;
else
Decl_Node := Empty;
end if;
-- Full type declaration or private type declaration, must have IS
if Token = Tok_Equal then
TF_Is;
Scan; -- past = used in place of IS
elsif Token = Tok_Renames then
Error_Msg_SC ("RENAMES should be IS");
Scan; -- past RENAMES used in place of IS
else
TF_Is;
end if;
-- First an error check, if we have two identifiers in a row, a likely
-- possibility is that the first of the identifiers is an incorrectly
-- spelled keyword.
if Token = Tok_Identifier then
declare
SS : Saved_Scan_State;
I2 : Boolean;
begin
Save_Scan_State (SS);
Scan; -- past initial identifier
I2 := (Token = Tok_Identifier);
Restore_Scan_State (SS);
if I2
and then
(Bad_Spelling_Of (Tok_Abstract) or else
Bad_Spelling_Of (Tok_Access) or else
Bad_Spelling_Of (Tok_Aliased) or else
Bad_Spelling_Of (Tok_Constant))
then
null;
end if;
end;
end if;
-- Check for misuse of Ada 95 keyword abstract in Ada 83 mode
if Token_Name = Name_Abstract then
Check_95_Keyword (Tok_Abstract, Tok_Tagged);
Check_95_Keyword (Tok_Abstract, Tok_New);
end if;
-- Check cases of misuse of ABSTRACT
if Token = Tok_Abstract then
Abstract_Present := True;
Abstract_Loc := Token_Ptr;
Scan; -- past ABSTRACT
if Token = Tok_Limited
or else Token = Tok_Private
or else Token = Tok_Record
or else Token = Tok_Null
then
Error_Msg_AP ("TAGGED expected");
end if;
else
Abstract_Present := False;
Abstract_Loc := No_Location;
end if;
-- Check for misuse of Ada 95 keyword Tagged
if Token_Name = Name_Tagged then
Check_95_Keyword (Tok_Tagged, Tok_Private);
Check_95_Keyword (Tok_Tagged, Tok_Limited);
Check_95_Keyword (Tok_Tagged, Tok_Record);
end if;
-- Special check for misuse of Aliased
if Token = Tok_Aliased or else Token_Name = Name_Aliased then
Error_Msg_SC ("ALIASED not allowed in type definition");
Scan; -- past ALIASED
end if;
-- The following procesing deals with either a private type declaration
-- or a full type declaration. In the private type case, we build the
-- N_Private_Type_Declaration node, setting its Tagged_Present and
-- Limited_Present flags, on encountering the Private keyword, and
-- leave Typedef_Node set to Empty. For the full type declaration
-- case, Typedef_Node gets set to the type definition.
Typedef_Node := Empty;
-- Switch on token following the IS. The loop normally runs once. It
-- only runs more than once if an error is detected, to try again after
-- detecting and fixing up the error.
loop
case Token is
when Tok_Access =>
Typedef_Node := P_Access_Type_Definition;
TF_Semicolon;
exit;
when Tok_Array =>
Typedef_Node := P_Array_Type_Definition;
TF_Semicolon;
exit;
when Tok_Delta =>
Typedef_Node := P_Fixed_Point_Definition;
TF_Semicolon;
exit;
when Tok_Digits =>
Typedef_Node := P_Floating_Point_Definition;
TF_Semicolon;
exit;
when Tok_In =>
Ignore (Tok_In);
when Tok_Integer_Literal =>
T_Range;
Typedef_Node := P_Signed_Integer_Type_Definition;
TF_Semicolon;
exit;
when Tok_Null =>
Typedef_Node := P_Record_Definition;
TF_Semicolon;
exit;
when Tok_Left_Paren =>
Typedef_Node := P_Enumeration_Type_Definition;
End_Labl :=
Make_Identifier (Token_Ptr,
Chars => Chars (Ident_Node));
Set_Comes_From_Source (End_Labl, False);
Set_End_Label (Typedef_Node, End_Labl);
TF_Semicolon;
exit;
when Tok_Mod =>
Typedef_Node := P_Modular_Type_Definition;
TF_Semicolon;
exit;
when Tok_New =>
Typedef_Node := P_Derived_Type_Def_Or_Private_Ext_Decl;
if Nkind (Typedef_Node) = N_Derived_Type_Definition
and then Present (Record_Extension_Part (Typedef_Node))
then
End_Labl :=
Make_Identifier (Token_Ptr,
Chars => Chars (Ident_Node));
Set_Comes_From_Source (End_Labl, False);
Set_End_Label
(Record_Extension_Part (Typedef_Node), End_Labl);
end if;
TF_Semicolon;
exit;
when Tok_Range =>
Typedef_Node := P_Signed_Integer_Type_Definition;
TF_Semicolon;
exit;
when Tok_Record =>
Typedef_Node := P_Record_Definition;
End_Labl :=
Make_Identifier (Token_Ptr,
Chars => Chars (Ident_Node));
Set_Comes_From_Source (End_Labl, False);
Set_End_Label (Typedef_Node, End_Labl);
TF_Semicolon;
exit;
when Tok_Tagged =>
Scan; -- past TAGGED
if Token = Tok_Abstract then
Error_Msg_SC ("ABSTRACT must come before TAGGED");
Abstract_Present := True;
Abstract_Loc := Token_Ptr;
Scan; -- past ABSTRACT
end if;
if Token = Tok_Limited then
Scan; -- past LIMITED
-- TAGGED LIMITED PRIVATE case
if Token = Tok_Private then
Decl_Node :=
New_Node (N_Private_Type_Declaration, Type_Loc);
Set_Tagged_Present (Decl_Node, True);
Set_Limited_Present (Decl_Node, True);
Scan; -- past PRIVATE
-- TAGGED LIMITED RECORD
else
Typedef_Node := P_Record_Definition;
Set_Tagged_Present (Typedef_Node, True);
Set_Limited_Present (Typedef_Node, True);
End_Labl :=
Make_Identifier (Token_Ptr,
Chars => Chars (Ident_Node));
Set_Comes_From_Source (End_Labl, False);
Set_End_Label (Typedef_Node, End_Labl);
end if;
else
-- TAGGED PRIVATE
if Token = Tok_Private then
Decl_Node :=
New_Node (N_Private_Type_Declaration, Type_Loc);
Set_Tagged_Present (Decl_Node, True);
Scan; -- past PRIVATE
-- TAGGED RECORD
else
Typedef_Node := P_Record_Definition;
Set_Tagged_Present (Typedef_Node, True);
End_Labl :=
Make_Identifier (Token_Ptr,
Chars => Chars (Ident_Node));
Set_Comes_From_Source (End_Labl, False);
Set_End_Label (Typedef_Node, End_Labl);
end if;
end if;
TF_Semicolon;
exit;
when Tok_Private =>
Decl_Node := New_Node (N_Private_Type_Declaration, Type_Loc);
Scan; -- past PRIVATE
TF_Semicolon;
exit;
when Tok_Limited =>
Scan; -- past LIMITED
loop
if Token = Tok_Tagged then
Error_Msg_SC ("TAGGED must come before LIMITED");
Scan; -- past TAGGED
elsif Token = Tok_Abstract then
Error_Msg_SC ("ABSTRACT must come before LIMITED");
Scan; -- past ABSTRACT
else
exit;
end if;
end loop;
-- LIMITED RECORD or LIMITED NULL RECORD
if Token = Tok_Record or else Token = Tok_Null then
if Ada_83 then
Error_Msg_SP
("(Ada 83) limited record declaration not allowed!");
end if;
Typedef_Node := P_Record_Definition;
Set_Limited_Present (Typedef_Node, True);
-- LIMITED PRIVATE is the only remaining possibility here
else
Decl_Node := New_Node (N_Private_Type_Declaration, Type_Loc);
Set_Limited_Present (Decl_Node, True);
T_Private; -- past PRIVATE (or complain if not there!)
end if;
TF_Semicolon;
exit;
-- Here we have an identifier after the IS, which is certainly
-- wrong and which might be one of several different mistakes.
when Tok_Identifier =>
-- First case, if identifier is on same line, then probably we
-- have something like "type X is Integer .." and the best
-- diagnosis is a missing NEW. Note: the missing new message
-- will be posted by P_Derived_Type_Def_Or_Private_Ext_Decl.
if not Token_Is_At_Start_Of_Line then
Typedef_Node := P_Derived_Type_Def_Or_Private_Ext_Decl;
TF_Semicolon;
-- If the identifier is at the start of the line, and is in the
-- same column as the type declaration itself then we consider
-- that we had a missing type definition on the previous line
elsif Start_Column <= Type_Start_Col then
Error_Msg_AP ("type definition expected");
Typedef_Node := Error;
-- If the identifier is at the start of the line, and is in
-- a column to the right of the type declaration line, then we
-- may have something like:
-- type x is
-- r : integer
-- and the best diagnosis is a missing record keyword
else
Typedef_Node := P_Record_Definition;
TF_Semicolon;
end if;
exit;
-- Anything else is an error
when others =>
if Bad_Spelling_Of (Tok_Access)
or else
Bad_Spelling_Of (Tok_Array)
or else
Bad_Spelling_Of (Tok_Delta)
or else
Bad_Spelling_Of (Tok_Digits)
or else
Bad_Spelling_Of (Tok_Limited)
or else
Bad_Spelling_Of (Tok_Private)
or else
Bad_Spelling_Of (Tok_Range)
or else
Bad_Spelling_Of (Tok_Record)
or else
Bad_Spelling_Of (Tok_Tagged)
then
null;
else
Error_Msg_AP ("type definition expected");
raise Error_Resync;
end if;
end case;
end loop;
-- For the private type declaration case, the private type declaration
-- node has been built, with the Tagged_Present and Limited_Present
-- flags set as needed, and Typedef_Node is left set to Empty.
if No (Typedef_Node) then
Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
Set_Abstract_Present (Decl_Node, Abstract_Present);
-- For a private extension declaration, Typedef_Node contains the
-- N_Private_Extension_Declaration node, which we now complete. Note
-- that the private extension declaration, unlike a full type
-- declaration, does permit unknown discriminants.
elsif Nkind (Typedef_Node) = N_Private_Extension_Declaration then
Decl_Node := Typedef_Node;
Set_Sloc (Decl_Node, Type_Loc);
Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
Set_Abstract_Present (Typedef_Node, Abstract_Present);
-- In the full type declaration case, Typedef_Node has the type
-- definition and here is where we build the full type declaration
-- node. This is also where we check for improper use of an unknown
-- discriminant part (not allowed for full type declaration).
else
if Nkind (Typedef_Node) = N_Record_Definition
or else (Nkind (Typedef_Node) = N_Derived_Type_Definition
and then Present (Record_Extension_Part (Typedef_Node)))
then
Set_Abstract_Present (Typedef_Node, Abstract_Present);
elsif Abstract_Present then
Error_Msg ("ABSTRACT not allowed here, ignored", Abstract_Loc);
end if;
Decl_Node := New_Node (N_Full_Type_Declaration, Type_Loc);
Set_Type_Definition (Decl_Node, Typedef_Node);
if Unknown_Dis then
Error_Msg
("Full type declaration cannot have unknown discriminants",
Discr_Sloc);
end if;
end if;
-- Remaining processing is common for all three cases
Set_Defining_Identifier (Decl_Node, Ident_Node);
Set_Discriminant_Specifications (Decl_Node, Discr_List);
return Decl_Node;
end P_Type_Declaration;
----------------------------------
-- 3.2.1 Full Type Declaration --
----------------------------------
-- Parsed by P_Type_Declaration (3.2.1)
----------------------------
-- 3.2.1 Type Definition --
----------------------------
-- Parsed by P_Type_Declaration (3.2.1)
--------------------------------
-- 3.2.2 Subtype Declaration --
--------------------------------
-- SUBTYPE_DECLARATION ::=
-- subtype DEFINING_IDENTIFIER is SUBTYPE_INDICATION;
-- The caller has checked that the initial token is SUBTYPE
-- Error recovery: can raise Error_Resync
function P_Subtype_Declaration return Node_Id is
Decl_Node : Node_Id;
begin
Decl_Node := New_Node (N_Subtype_Declaration, Token_Ptr);
Scan; -- past SUBTYPE
Set_Defining_Identifier (Decl_Node, P_Defining_Identifier (C_Is));
TF_Is;
if Token = Tok_New then
Error_Msg_SC ("NEW ignored (only allowed in type declaration)");
Scan; -- past NEW
end if;
Set_Subtype_Indication (Decl_Node, P_Subtype_Indication);
TF_Semicolon;
return Decl_Node;
end P_Subtype_Declaration;
-------------------------------
-- 3.2.2 Subtype Indication --
-------------------------------
-- SUBTYPE_INDICATION ::= SUBTYPE_MARK [CONSTRAINT]
-- Error recovery: can raise Error_Resync
function P_Subtype_Indication return Node_Id is
Type_Node : Node_Id;
begin
if Token = Tok_Identifier or else Token = Tok_Operator_Symbol then
Type_Node := P_Subtype_Mark;
return P_Subtype_Indication (Type_Node);
else
-- Check for error of using record definition and treat it nicely,
-- otherwise things are really messed up, so resynchronize.
if Token = Tok_Record then
Error_Msg_SC ("anonymous record definitions are not permitted");
Discard_Junk_Node (P_Record_Definition);
return Error;
else
Error_Msg_AP ("subtype indication expected");
raise Error_Resync;
end if;
end if;
end P_Subtype_Indication;
-- The following function is identical except that it is called with
-- the subtype mark already scanned out, and it scans out the constraint
-- Error recovery: can raise Error_Resync
function P_Subtype_Indication (Subtype_Mark : Node_Id) return Node_Id is
Indic_Node : Node_Id;
Constr_Node : Node_Id;
begin
Constr_Node := P_Constraint_Opt;
if No (Constr_Node) then
return Subtype_Mark;
else
Indic_Node := New_Node (N_Subtype_Indication, Sloc (Subtype_Mark));
Set_Subtype_Mark (Indic_Node, Check_Subtype_Mark (Subtype_Mark));
Set_Constraint (Indic_Node, Constr_Node);
return Indic_Node;
end if;
end P_Subtype_Indication;
-------------------------
-- 3.2.2 Subtype Mark --
-------------------------
-- SUBTYPE_MARK ::= subtype_NAME;
-- Note: The subtype mark which appears after an IN or NOT IN
-- operator is parsed by P_Range_Or_Subtype_Mark (3.5)
-- Error recovery: cannot raise Error_Resync
function P_Subtype_Mark return Node_Id is
begin
return P_Subtype_Mark_Resync;
exception
when Error_Resync =>
return Error;
end P_Subtype_Mark;
-- This routine differs from P_Subtype_Mark in that it insists that an
-- identifier be present, and if it is not, it raises Error_Resync.
-- Error recovery: can raise Error_Resync
function P_Subtype_Mark_Resync return Node_Id is
Type_Node : Node_Id;
begin
if Token = Tok_Access then
Error_Msg_SC ("anonymous access type definition not allowed here");
Scan; -- past ACCESS
end if;
if Token = Tok_Array then
Error_Msg_SC ("anonymous array definition not allowed here");
Discard_Junk_Node (P_Array_Type_Definition);
return Error;
else
Type_Node := P_Qualified_Simple_Name_Resync;
-- Check for a subtype mark attribute. The only valid possibilities
-- are 'CLASS and 'BASE. Anything else is a definite error. We may
-- as well catch it here.
if Token = Tok_Apostrophe then
return P_Subtype_Mark_Attribute (Type_Node);
else
return Type_Node;
end if;
end if;
end P_Subtype_Mark_Resync;
-- The following function is called to scan out a subtype mark attribute.
-- The caller has already scanned out the subtype mark, which is passed in
-- as the argument, and has checked that the current token is apostrophe.
-- Only a special subclass of attributes, called type attributes
-- (see Snames package) are allowed in this syntactic position.
-- Note: if the apostrophe is followed by other than an identifier, then
-- the input expression is returned unchanged, and the scan pointer is
-- left pointing to the apostrophe.
-- Error recovery: can raise Error_Resync
function P_Subtype_Mark_Attribute (Type_Node : Node_Id) return Node_Id is
Attr_Node : Node_Id := Empty;
Scan_State : Saved_Scan_State;
Prefix : Node_Id;
begin
Prefix := Check_Subtype_Mark (Type_Node);
if Prefix = Error then
raise Error_Resync;
end if;
-- Loop through attributes appearing (more than one can appear as for
-- for example in X'Base'Class). We are at an apostrophe on entry to
-- this loop, and it runs once for each attribute parsed, with
-- Prefix being the current possible prefix if it is an attribute.
loop
Save_Scan_State (Scan_State); -- at Apostrophe
Scan; -- past apostrophe
if Token /= Tok_Identifier then
Restore_Scan_State (Scan_State); -- to apostrophe
return Prefix; -- no attribute after all
elsif not Is_Type_Attribute_Name (Token_Name) then
Error_Msg_N
("attribute & may not be used in a subtype mark", Token_Node);
raise Error_Resync;
else
Attr_Node :=
Make_Attribute_Reference (Prev_Token_Ptr,
Prefix => Prefix,
Attribute_Name => Token_Name);
Delete_Node (Token_Node);
Scan; -- past type attribute identifier
end if;
exit when Token /= Tok_Apostrophe;
Prefix := Attr_Node;
end loop;
-- Fall through here after scanning type attribute
return Attr_Node;
end P_Subtype_Mark_Attribute;
-----------------------
-- 3.2.2 Constraint --
-----------------------
-- CONSTRAINT ::= SCALAR_CONSTRAINT | COMPOSITE_CONSTRAINT
-- SCALAR_CONSTRAINT ::=
-- RANGE_CONSTRAINT | DIGITS_CONSTRAINT | DELTA_CONSTRAINT
-- COMPOSITE_CONSTRAINT ::=
-- INDEX_CONSTRAINT | DISCRIMINANT_CONSTRAINT
-- If no constraint is present, this function returns Empty
-- Error recovery: can raise Error_Resync
function P_Constraint_Opt return Node_Id is
begin
if Token = Tok_Range
or else Bad_Spelling_Of (Tok_Range)
then
return P_Range_Constraint;
elsif Token = Tok_Digits
or else Bad_Spelling_Of (Tok_Digits)
then
return P_Digits_Constraint;
elsif Token = Tok_Delta
or else Bad_Spelling_Of (Tok_Delta)
then
return P_Delta_Constraint;
elsif Token = Tok_Left_Paren then
return P_Index_Or_Discriminant_Constraint;
elsif Token = Tok_In then
Ignore (Tok_In);
return P_Constraint_Opt;
else
return Empty;
end if;
end P_Constraint_Opt;
------------------------------
-- 3.2.2 Scalar Constraint --
------------------------------
-- Parsed by P_Constraint_Opt (3.2.2)
---------------------------------
-- 3.2.2 Composite Constraint --
---------------------------------
-- Parsed by P_Constraint_Opt (3.2.2)
--------------------------------------------------------
-- 3.3 Identifier Declarations (Also 7.4, 8.5, 11.1) --
--------------------------------------------------------
-- This routine scans out a declaration starting with an identifier:
-- OBJECT_DECLARATION ::=
-- DEFINING_IDENTIFIER_LIST : [constant] [aliased]
-- SUBTYPE_INDICATION [:= EXPRESSION];
-- | DEFINING_IDENTIFIER_LIST : [constant] [aliased]
-- ARRAY_TYPE_DEFINITION [:= EXPRESSION];
-- NUMBER_DECLARATION ::=
-- DEFINING_IDENTIFIER_LIST : constant ::= static_EXPRESSION;
-- OBJECT_RENAMING_DECLARATION ::=
-- DEFINING_IDENTIFIER : SUBTYPE_MARK renames object_NAME;
-- EXCEPTION_RENAMING_DECLARATION ::=
-- DEFINING_IDENTIFIER : exception renames exception_NAME;
-- EXCEPTION_DECLARATION ::=
-- DEFINING_IDENTIFIER_LIST : exception;
-- Note that the ALIASED indication in an object declaration is
-- marked by a flag in the parent node.
-- The caller has checked that the initial token is an identifier
-- The value returned is a list of declarations, one for each identifier
-- in the list (as described in Sinfo, we always split up multiple
-- declarations into the equivalent sequence of single declarations
-- using the More_Ids and Prev_Ids flags to preserve the source).
-- If the identifier turns out to be a probable statement rather than
-- an identifier, then the scan is left pointing to the identifier and
-- No_List is returned.
-- Error recovery: can raise Error_Resync
procedure P_Identifier_Declarations
(Decls : List_Id;
Done : out Boolean;
In_Spec : Boolean)
is
Decl_Node : Node_Id;
Type_Node : Node_Id;
Ident_Sloc : Source_Ptr;
Scan_State : Saved_Scan_State;
List_OK : Boolean := True;
Ident : Nat;
Init_Expr : Node_Id;
Init_Loc : Source_Ptr;
Con_Loc : Source_Ptr;
Idents : array (Int range 1 .. 4096) of Entity_Id;
-- Used to save identifiers in the identifier list. The upper bound
-- of 4096 is expected to be infinite in practice, and we do not even
-- bother to check if this upper bound is exceeded.
Num_Idents : Nat := 1;
-- Number of identifiers stored in Idents
procedure No_List;
-- This procedure is called in renames cases to make sure that we do
-- not have more than one identifier. If we do have more than one
-- then an error message is issued (and the declaration is split into
-- multiple declarations)
function Token_Is_Renames return Boolean;
-- Checks if current token is RENAMES, and if so, scans past it and
-- returns True, otherwise returns False. Includes checking for some
-- common error cases.
procedure No_List is
begin
if Num_Idents > 1 then
Error_Msg ("identifier list not allowed for RENAMES",
Sloc (Idents (2)));
end if;
List_OK := False;
end No_List;
function Token_Is_Renames return Boolean is
At_Colon : Saved_Scan_State;
begin
if Token = Tok_Colon then
Save_Scan_State (At_Colon);
Scan; -- past colon
Check_Misspelling_Of (Tok_Renames);
if Token = Tok_Renames then
Error_Msg_SP ("extra "":"" ignored");
Scan; -- past RENAMES
return True;
else
Restore_Scan_State (At_Colon);
return False;
end if;
else
Check_Misspelling_Of (Tok_Renames);
if Token = Tok_Renames then
Scan; -- past RENAMES
return True;
else
return False;
end if;
end if;
end Token_Is_Renames;
-- Start of processing for P_Identifier_Declarations
begin
Ident_Sloc := Token_Ptr;
Save_Scan_State (Scan_State); -- at first identifier
Idents (1) := P_Defining_Identifier (C_Comma_Colon);
-- If we have a colon after the identifier, then we can assume that
-- this is in fact a valid identifier declaration and can steam ahead.
if Token = Tok_Colon then
Scan; -- past colon
-- If we have a comma, then scan out the list of identifiers
elsif Token = Tok_Comma then
while Comma_Present loop
Num_Idents := Num_Idents + 1;
Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
end loop;
Save_Scan_State (Scan_State); -- at colon
T_Colon;
-- If we have identifier followed by := then we assume that what is
-- really meant is an assignment statement. The assignment statement
-- is scanned out and added to the list of declarations. An exception
-- occurs if the := is followed by the keyword constant, in which case
-- we assume it was meant to be a colon.
elsif Token = Tok_Colon_Equal then
Scan; -- past :=
if Token = Tok_Constant then
Error_Msg_SP ("colon expected");
else
Restore_Scan_State (Scan_State);
Statement_When_Declaration_Expected (Decls, Done, In_Spec);
return;
end if;
-- If we have an IS keyword, then assume the TYPE keyword was missing
elsif Token = Tok_Is then
Restore_Scan_State (Scan_State);
Append_To (Decls, P_Type_Declaration);
Done := False;
return;
-- Otherwise we have an error situation
else
Restore_Scan_State (Scan_State);
-- First case is possible misuse of PROTECTED in Ada 83 mode. If
-- so, fix the keyword and return to scan the protected declaration.
if Token_Name = Name_Protected then
Check_95_Keyword (Tok_Protected, Tok_Identifier);
Check_95_Keyword (Tok_Protected, Tok_Type);
Check_95_Keyword (Tok_Protected, Tok_Body);
if Token = Tok_Protected then
Done := False;
return;
end if;
-- Check misspelling possibilities. If so, correct the misspelling
-- and return to scan out the resulting declaration.
elsif Bad_Spelling_Of (Tok_Function)
or else Bad_Spelling_Of (Tok_Procedure)
or else Bad_Spelling_Of (Tok_Package)
or else Bad_Spelling_Of (Tok_Pragma)
or else Bad_Spelling_Of (Tok_Protected)
or else Bad_Spelling_Of (Tok_Generic)
or else Bad_Spelling_Of (Tok_Subtype)
or else Bad_Spelling_Of (Tok_Type)
or else Bad_Spelling_Of (Tok_Task)
or else Bad_Spelling_Of (Tok_Use)
or else Bad_Spelling_Of (Tok_For)
then
Done := False;
return;
-- Otherwise we definitely have an ordinary identifier with a junk
-- token after it. Just complain that we expect a declaration, and
-- skip to a semicolon
else
Set_Declaration_Expected;
Resync_Past_Semicolon;
Done := False;
return;
end if;
end if;
-- Come here with an identifier list and colon scanned out. We now
-- build the nodes for the declarative items. One node is built for
-- each identifier in the list, with the type information being
-- repeated by rescanning the appropriate section of source.
-- First an error check, if we have two identifiers in a row, a likely
-- possibility is that the first of the identifiers is an incorrectly
-- spelled keyword.
if Token = Tok_Identifier then
declare
SS : Saved_Scan_State;
I2 : Boolean;
begin
Save_Scan_State (SS);
Scan; -- past initial identifier
I2 := (Token = Tok_Identifier);
Restore_Scan_State (SS);
if I2
and then
(Bad_Spelling_Of (Tok_Access) or else
Bad_Spelling_Of (Tok_Aliased) or else
Bad_Spelling_Of (Tok_Constant))
then
null;
end if;
end;
end if;
-- Loop through identifiers
Ident := 1;
Ident_Loop : loop
-- Check for some cases of misused Ada 95 keywords
if Token_Name = Name_Aliased then
Check_95_Keyword (Tok_Aliased, Tok_Array);
Check_95_Keyword (Tok_Aliased, Tok_Identifier);
Check_95_Keyword (Tok_Aliased, Tok_Constant);
end if;
-- Constant cases
if Token = Tok_Constant then
Con_Loc := Token_Ptr;
Scan; -- past CONSTANT
-- Number declaration, initialization required
Init_Expr := Init_Expr_Opt;
if Present (Init_Expr) then
Decl_Node := New_Node (N_Number_Declaration, Ident_Sloc);
Set_Expression (Decl_Node, Init_Expr);
-- Constant object declaration
else
Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
Set_Constant_Present (Decl_Node, True);
if Token_Name = Name_Aliased then
Check_95_Keyword (Tok_Aliased, Tok_Array);
Check_95_Keyword (Tok_Aliased, Tok_Identifier);
end if;
if Token = Tok_Aliased then
Error_Msg_SC ("ALIASED should be before CONSTANT");
Scan; -- past ALIASED
Set_Aliased_Present (Decl_Node, True);
end if;
if Token = Tok_Array then
Set_Object_Definition
(Decl_Node, P_Array_Type_Definition);
else
Set_Object_Definition (Decl_Node, P_Subtype_Indication);
end if;
if Token = Tok_Renames then
Error_Msg
("CONSTANT not permitted in renaming declaration",
Con_Loc);
Scan; -- Past renames
Discard_Junk_Node (P_Name);
end if;
end if;
-- Exception cases
elsif Token = Tok_Exception then
Scan; -- past EXCEPTION
if Token_Is_Renames then
No_List;
Decl_Node :=
New_Node (N_Exception_Renaming_Declaration, Ident_Sloc);
Set_Name (Decl_Node, P_Qualified_Simple_Name_Resync);
No_Constraint;
else
Decl_Node := New_Node (N_Exception_Declaration, Prev_Token_Ptr);
end if;
-- Aliased case (note that an object definition is required)
elsif Token = Tok_Aliased then
Scan; -- past ALIASED
Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
Set_Aliased_Present (Decl_Node, True);
if Token = Tok_Constant then
Scan; -- past CONSTANT
Set_Constant_Present (Decl_Node, True);
end if;
if Token = Tok_Array then
Set_Object_Definition
(Decl_Node, P_Array_Type_Definition);
else
Set_Object_Definition (Decl_Node, P_Subtype_Indication);
end if;
-- Array case
elsif Token = Tok_Array then
Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
Set_Object_Definition (Decl_Node, P_Array_Type_Definition);
-- Subtype indication case
else
Type_Node := P_Subtype_Mark;
-- Object renaming declaration
if Token_Is_Renames then
No_List;
Decl_Node :=
New_Node (N_Object_Renaming_Declaration, Ident_Sloc);
Set_Subtype_Mark (Decl_Node, Type_Node);
Set_Name (Decl_Node, P_Name);
-- Object declaration
else
Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
Set_Object_Definition
(Decl_Node, P_Subtype_Indication (Type_Node));
-- RENAMES at this point means that we had the combination of
-- a constraint on the Type_Node and renames, which is illegal
if Token_Is_Renames then
Error_Msg_N
("constraint not allowed in object renaming declaration",
Constraint (Object_Definition (Decl_Node)));
raise Error_Resync;
end if;
end if;
end if;
-- Scan out initialization, allowed only for object declaration
Init_Loc := Token_Ptr;
Init_Expr := Init_Expr_Opt;
if Present (Init_Expr) then
if Nkind (Decl_Node) = N_Object_Declaration then
Set_Expression (Decl_Node, Init_Expr);
else
Error_Msg ("initialization not allowed here", Init_Loc);
end if;
end if;
TF_Semicolon;
Set_Defining_Identifier (Decl_Node, Idents (Ident));
if List_OK then
if Ident < Num_Idents then
Set_More_Ids (Decl_Node, True);
end if;
if Ident > 1 then
Set_Prev_Ids (Decl_Node, True);
end if;
end if;
Append (Decl_Node, Decls);
exit Ident_Loop when Ident = Num_Idents;
Restore_Scan_State (Scan_State);
T_Colon;
Ident := Ident + 1;
end loop Ident_Loop;
Done := False;
end P_Identifier_Declarations;
-------------------------------
-- 3.3.1 Object Declaration --
-------------------------------
-- OBJECT DECLARATION ::=
-- DEFINING_IDENTIFIER_LIST : [aliased] [constant]
-- SUBTYPE_INDICATION [:= EXPRESSION];
-- | DEFINING_IDENTIFIER_LIST : [aliased] [constant]
-- ARRAY_TYPE_DEFINITION [:= EXPRESSION];
-- | SINGLE_TASK_DECLARATION
-- | SINGLE_PROTECTED_DECLARATION
-- Cases starting with TASK are parsed by P_Task (9.1)
-- Cases starting with PROTECTED are parsed by P_Protected (9.4)
-- All other cases are parsed by P_Identifier_Declarations (3.3)
-------------------------------------
-- 3.3.1 Defining Identifier List --
-------------------------------------
-- DEFINING_IDENTIFIER_LIST ::=
-- DEFINING_IDENTIFIER {, DEFINING_IDENTIFIER}
-- Always parsed by the construct in which it appears. See special
-- section on "Handling of Defining Identifier Lists" in this unit.
-------------------------------
-- 3.3.2 Number Declaration --
-------------------------------
-- Parsed by P_Identifier_Declarations (3.3)
-------------------------------------------------------------------------
-- 3.4 Derived Type Definition or Private Extension Declaration (7.3) --
-------------------------------------------------------------------------
-- DERIVED_TYPE_DEFINITION ::=
-- [abstract] new parent_SUBTYPE_INDICATION [RECORD_EXTENSION_PART]
-- PRIVATE_EXTENSION_DECLARATION ::=
-- type DEFINING_IDENTIFIER [DISCRIMINANT_PART] is
-- [abstract] new ancestor_SUBTYPE_INDICATION with PRIVATE;
-- RECORD_EXTENSION_PART ::= with RECORD_DEFINITION
-- The caller has already scanned out the part up to the NEW, and Token
-- either contains Tok_New (or ought to, if it doesn't this procedure
-- will post an appropriate "NEW expected" message).
-- Note: the caller is responsible for filling in the Sloc field of
-- the returned node in the private extension declaration case as
-- well as the stuff relating to the discriminant part.
-- Error recovery: can raise Error_Resync;
function P_Derived_Type_Def_Or_Private_Ext_Decl return Node_Id is
Typedef_Node : Node_Id;
Typedecl_Node : Node_Id;
begin
Typedef_Node := New_Node (N_Derived_Type_Definition, Token_Ptr);
T_New;
if Token = Tok_Abstract then
Error_Msg_SC ("ABSTRACT must come before NEW, not after");
Scan;
end if;
Set_Subtype_Indication (Typedef_Node, P_Subtype_Indication);
-- Deal with record extension, note that we assume that a WITH is
-- missing in the case of "type X is new Y record ..." or in the
-- case of "type X is new Y null record".
if Token = Tok_With
or else Token = Tok_Record
or else Token = Tok_Null
then
T_With; -- past WITH or give error message
if Token = Tok_Limited then
Error_Msg_SC
("LIMITED keyword not allowed in private extension");
Scan; -- ignore LIMITED
end if;
-- Private extension declaration
if Token = Tok_Private then
Scan; -- past PRIVATE
-- Throw away the type definition node and build the type
-- declaration node. Note the caller must set the Sloc,
-- Discriminant_Specifications, Unknown_Discriminants_Present,
-- and Defined_Identifier fields in the returned node.
Typedecl_Node :=
Make_Private_Extension_Declaration (No_Location,
Defining_Identifier => Empty,
Subtype_Indication => Subtype_Indication (Typedef_Node),
Abstract_Present => Abstract_Present (Typedef_Node));
Delete_Node (Typedef_Node);
return Typedecl_Node;
-- Derived type definition with record extension part
else
Set_Record_Extension_Part (Typedef_Node, P_Record_Definition);
return Typedef_Node;
end if;
-- Derived type definition with no record extension part
else
return Typedef_Node;
end if;
end P_Derived_Type_Def_Or_Private_Ext_Decl;
---------------------------
-- 3.5 Range Constraint --
---------------------------
-- RANGE_CONSTRAINT ::= range RANGE
-- The caller has checked that the initial token is RANGE
-- Error recovery: cannot raise Error_Resync
function P_Range_Constraint return Node_Id is
Range_Node : Node_Id;
begin
Range_Node := New_Node (N_Range_Constraint, Token_Ptr);
Scan; -- past RANGE
Set_Range_Expression (Range_Node, P_Range);
return Range_Node;
end P_Range_Constraint;
----------------
-- 3.5 Range --
----------------
-- RANGE ::=
-- RANGE_ATTRIBUTE_REFERENCE | SIMPLE_EXPRESSION .. SIMPLE_EXPRESSION
-- Note: the range that appears in a membership test is parsed by
-- P_Range_Or_Subtype_Mark (3.5).
-- Error recovery: cannot raise Error_Resync
function P_Range return Node_Id is
Expr_Node : Node_Id;
Range_Node : Node_Id;
begin
Expr_Node := P_Simple_Expression_Or_Range_Attribute;
if Expr_Form = EF_Range_Attr then
return Expr_Node;
elsif Token = Tok_Dot_Dot then
Range_Node := New_Node (N_Range, Token_Ptr);
Set_Low_Bound (Range_Node, Expr_Node);
Scan; -- past ..
Expr_Node := P_Expression;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Range_Node, Expr_Node);
return Range_Node;
-- Anything else is an error
else
T_Dot_Dot; -- force missing .. message
return Error;
end if;
end P_Range;
----------------------------------
-- 3.5 P_Range_Or_Subtype_Mark --
----------------------------------
-- RANGE ::=
-- RANGE_ATTRIBUTE_REFERENCE
-- | SIMPLE_EXPRESSION .. SIMPLE_EXPRESSION
-- This routine scans out the range or subtype mark that forms the right
-- operand of a membership test.
-- Note: as documented in the Sinfo interface, although the syntax only
-- allows a subtype mark, we in fact allow any simple expression to be
-- returned from this routine. The semantics is responsible for issuing
-- an appropriate message complaining if the argument is not a name.
-- This simplifies the coding and error recovery processing in the
-- parser, and in any case it is preferable not to consider this a
-- syntax error and to continue with the semantic analysis.
-- Error recovery: cannot raise Error_Resync
function P_Range_Or_Subtype_Mark return Node_Id is
Expr_Node : Node_Id;
Range_Node : Node_Id;
begin
Expr_Node := P_Simple_Expression_Or_Range_Attribute;
if Expr_Form = EF_Range_Attr then
return Expr_Node;
-- Simple_Expression .. Simple_Expression
elsif Token = Tok_Dot_Dot then
Check_Simple_Expression (Expr_Node);
Range_Node := New_Node (N_Range, Token_Ptr);
Set_Low_Bound (Range_Node, Expr_Node);
Scan; -- past ..
Set_High_Bound (Range_Node, P_Simple_Expression);
return Range_Node;
-- Case of subtype mark (optionally qualified simple name or an
-- attribute whose prefix is an optionally qualifed simple name)
elsif Expr_Form = EF_Simple_Name
or else Nkind (Expr_Node) = N_Attribute_Reference
then
-- Check for error of range constraint after a subtype mark
if Token = Tok_Range then
Error_Msg_SC
("range constraint not allowed in membership test");
Scan; -- past RANGE
raise Error_Resync;
-- Check for error of DIGITS or DELTA after a subtype mark
elsif Token = Tok_Digits or else Token = Tok_Delta then
Error_Msg_SC
("accuracy definition not allowed in membership test");
Scan; -- past DIGITS or DELTA
raise Error_Resync;
elsif Token = Tok_Apostrophe then
return P_Subtype_Mark_Attribute (Expr_Node);
else
return Expr_Node;
end if;
-- At this stage, we have some junk following the expression. We
-- really can't tell what is wrong, might be a missing semicolon,
-- or a missing THEN, or whatever. Our caller will figure it out!
else
return Expr_Node;
end if;
end P_Range_Or_Subtype_Mark;
----------------------------------------
-- 3.5.1 Enumeration Type Definition --
----------------------------------------
-- ENUMERATION_TYPE_DEFINITION ::=
-- (ENUMERATION_LITERAL_SPECIFICATION
-- {, ENUMERATION_LITERAL_SPECIFICATION})
-- The caller has already scanned out the TYPE keyword
-- Error recovery: can raise Error_Resync;
function P_Enumeration_Type_Definition return Node_Id is
Typedef_Node : Node_Id;
begin
Typedef_Node := New_Node (N_Enumeration_Type_Definition, Token_Ptr);
Set_Literals (Typedef_Node, New_List);
T_Left_Paren;
loop
Append (P_Enumeration_Literal_Specification, Literals (Typedef_Node));
exit when not Comma_Present;
end loop;
T_Right_Paren;
return Typedef_Node;
end P_Enumeration_Type_Definition;
----------------------------------------------
-- 3.5.1 Enumeration Literal Specification --
----------------------------------------------
-- ENUMERATION_LITERAL_SPECIFICATION ::=
-- DEFINING_IDENTIFIER | DEFINING_CHARACTER_LITERAL
-- Error recovery: can raise Error_Resync
function P_Enumeration_Literal_Specification return Node_Id is
begin
if Token = Tok_Char_Literal then
return P_Defining_Character_Literal;
else
return P_Defining_Identifier (C_Comma_Right_Paren);
end if;
end P_Enumeration_Literal_Specification;
---------------------------------------
-- 3.5.1 Defining_Character_Literal --
---------------------------------------
-- DEFINING_CHARACTER_LITERAL ::= CHARACTER_LITERAL
-- Error recovery: cannot raise Error_Resync
-- The caller has checked that the current token is a character literal
function P_Defining_Character_Literal return Node_Id is
Literal_Node : Node_Id;
begin
Literal_Node := Token_Node;
Change_Character_Literal_To_Defining_Character_Literal (Literal_Node);
Scan; -- past character literal
return Literal_Node;
end P_Defining_Character_Literal;
------------------------------------
-- 3.5.4 Integer Type Definition --
------------------------------------
-- Parsed by P_Type_Declaration (3.2.1)
-------------------------------------------
-- 3.5.4 Signed Integer Type Definition --
-------------------------------------------
-- SIGNED_INTEGER_TYPE_DEFINITION ::=
-- range static_SIMPLE_EXPRESSION .. static_SIMPLE_EXPRESSION
-- Normally the initial token on entry is RANGE, but in some
-- error conditions, the range token was missing and control is
-- passed with Token pointing to first token of the first expression.
-- Error recovery: cannot raise Error_Resync
function P_Signed_Integer_Type_Definition return Node_Id is
Typedef_Node : Node_Id;
Expr_Node : Node_Id;
begin
Typedef_Node := New_Node (N_Signed_Integer_Type_Definition, Token_Ptr);
if Token = Tok_Range then
Scan; -- past RANGE
end if;
Expr_Node := P_Expression;
Check_Simple_Expression (Expr_Node);
Set_Low_Bound (Typedef_Node, Expr_Node);
T_Dot_Dot;
Expr_Node := P_Expression;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Typedef_Node, Expr_Node);
return Typedef_Node;
end P_Signed_Integer_Type_Definition;
------------------------------------
-- 3.5.4 Modular Type Definition --
------------------------------------
-- MODULAR_TYPE_DEFINITION ::= mod static_EXPRESSION
-- The caller has checked that the initial token is MOD
-- Error recovery: cannot raise Error_Resync
function P_Modular_Type_Definition return Node_Id is
Typedef_Node : Node_Id;
begin
if Ada_83 then
Error_Msg_SC ("(Ada 83): modular types not allowed");
end if;
Typedef_Node := New_Node (N_Modular_Type_Definition, Token_Ptr);
Scan; -- past MOD
Set_Expression (Typedef_Node, P_Expression_No_Right_Paren);
-- Handle mod L..R cleanly
if Token = Tok_Dot_Dot then
Error_Msg_SC ("range not allowed for modular type");
Scan; -- past ..
Set_Expression (Typedef_Node, P_Expression_No_Right_Paren);
end if;
return Typedef_Node;
end P_Modular_Type_Definition;
---------------------------------
-- 3.5.6 Real Type Definition --
---------------------------------
-- Parsed by P_Type_Declaration (3.2.1)
--------------------------------------
-- 3.5.7 Floating Point Definition --
--------------------------------------
-- FLOATING_POINT_DEFINITION ::=
-- digits static_EXPRESSION [REAL_RANGE_SPECIFICATION]
-- Note: In Ada-83, the EXPRESSION must be a SIMPLE_EXPRESSION
-- The caller has checked that the initial token is DIGITS
-- Error recovery: cannot raise Error_Resync
function P_Floating_Point_Definition return Node_Id is
Digits_Loc : constant Source_Ptr := Token_Ptr;
Def_Node : Node_Id;
Expr_Node : Node_Id;
begin
Scan; -- past DIGITS
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression_In_Ada_83 (Expr_Node);
-- Handle decimal fixed-point defn with DIGITS/DELTA in wrong order
if Token = Tok_Delta then
Error_Msg_SC ("DELTA must come before DIGITS");
Def_Node := New_Node (N_Decimal_Fixed_Point_Definition, Digits_Loc);
Scan; -- past DELTA
Set_Delta_Expression (Def_Node, P_Expression_No_Right_Paren);
-- OK floating-point definition
else
Def_Node := New_Node (N_Floating_Point_Definition, Digits_Loc);
end if;
Set_Digits_Expression (Def_Node, Expr_Node);
Set_Real_Range_Specification (Def_Node, P_Real_Range_Specification_Opt);
return Def_Node;
end P_Floating_Point_Definition;
-------------------------------------
-- 3.5.7 Real Range Specification --
-------------------------------------
-- REAL_RANGE_SPECIFICATION ::=
-- range static_SIMPLE_EXPRESSION .. static_SIMPLE_EXPRESSION
-- Error recovery: cannot raise Error_Resync
function P_Real_Range_Specification_Opt return Node_Id is
Specification_Node : Node_Id;
Expr_Node : Node_Id;
begin
if Token = Tok_Range then
Specification_Node :=
New_Node (N_Real_Range_Specification, Token_Ptr);
Scan; -- past RANGE
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression (Expr_Node);
Set_Low_Bound (Specification_Node, Expr_Node);
T_Dot_Dot;
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Specification_Node, Expr_Node);
return Specification_Node;
else
return Empty;
end if;
end P_Real_Range_Specification_Opt;
-----------------------------------
-- 3.5.9 Fixed Point Definition --
-----------------------------------
-- FIXED_POINT_DEFINITION ::=
-- ORDINARY_FIXED_POINT_DEFINITION | DECIMAL_FIXED_POINT_DEFINITION
-- ORDINARY_FIXED_POINT_DEFINITION ::=
-- delta static_EXPRESSION REAL_RANGE_SPECIFICATION
-- DECIMAL_FIXED_POINT_DEFINITION ::=
-- delta static_EXPRESSION
-- digits static_EXPRESSION [REAL_RANGE_SPECIFICATION]
-- The caller has checked that the initial token is DELTA
-- Error recovery: cannot raise Error_Resync
function P_Fixed_Point_Definition return Node_Id is
Delta_Node : Node_Id;
Delta_Loc : Source_Ptr;
Def_Node : Node_Id;
Expr_Node : Node_Id;
begin
Delta_Loc := Token_Ptr;
Scan; -- past DELTA
Delta_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression_In_Ada_83 (Delta_Node);
if Token = Tok_Digits then
if Ada_83 then
Error_Msg_SC ("(Ada 83) decimal fixed type not allowed!");
end if;
Def_Node := New_Node (N_Decimal_Fixed_Point_Definition, Delta_Loc);
Scan; -- past DIGITS
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression_In_Ada_83 (Expr_Node);
Set_Digits_Expression (Def_Node, Expr_Node);
else
Def_Node := New_Node (N_Ordinary_Fixed_Point_Definition, Delta_Loc);
-- Range is required in ordinary fixed point case
if Token /= Tok_Range then
Error_Msg_AP ("range must be given for fixed-point type");
T_Range;
end if;
end if;
Set_Delta_Expression (Def_Node, Delta_Node);
Set_Real_Range_Specification (Def_Node, P_Real_Range_Specification_Opt);
return Def_Node;
end P_Fixed_Point_Definition;
--------------------------------------------
-- 3.5.9 Ordinary Fixed Point Definition --
--------------------------------------------
-- Parsed by P_Fixed_Point_Definition (3.5.9)
-------------------------------------------
-- 3.5.9 Decimal Fixed Point Definition --
-------------------------------------------
-- Parsed by P_Decimal_Point_Definition (3.5.9)
------------------------------
-- 3.5.9 Digits Constraint --
------------------------------
-- DIGITS_CONSTRAINT ::=
-- digits static_EXPRESSION [RANGE_CONSTRAINT]
-- Note: in Ada 83, the EXPRESSION must be a SIMPLE_EXPRESSION
-- The caller has checked that the initial token is DIGITS
function P_Digits_Constraint return Node_Id is
Constraint_Node : Node_Id;
Expr_Node : Node_Id;
begin
Constraint_Node := New_Node (N_Digits_Constraint, Token_Ptr);
Scan; -- past DIGITS
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression_In_Ada_83 (Expr_Node);
Set_Digits_Expression (Constraint_Node, Expr_Node);
if Token = Tok_Range then
Set_Range_Constraint (Constraint_Node, P_Range_Constraint);
end if;
return Constraint_Node;
end P_Digits_Constraint;
-----------------------------
-- 3.5.9 Delta Constraint --
-----------------------------
-- DELTA CONSTRAINT ::= DELTA STATIC_EXPRESSION [RANGE_CONSTRAINT]
-- Note: this is an obsolescent feature in Ada 95 (I.3)
-- Note: in Ada 83, the EXPRESSION must be a SIMPLE_EXPRESSION
-- The caller has checked that the initial token is DELTA
-- Error recovery: cannot raise Error_Resync
function P_Delta_Constraint return Node_Id is
Constraint_Node : Node_Id;
Expr_Node : Node_Id;
begin
Constraint_Node := New_Node (N_Delta_Constraint, Token_Ptr);
Scan; -- past DELTA
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression_In_Ada_83 (Expr_Node);
Set_Delta_Expression (Constraint_Node, Expr_Node);
if Token = Tok_Range then
Set_Range_Constraint (Constraint_Node, P_Range_Constraint);
end if;
return Constraint_Node;
end P_Delta_Constraint;
--------------------------------
-- 3.6 Array Type Definition --
--------------------------------
-- ARRAY_TYPE_DEFINITION ::=
-- UNCONSTRAINED_ARRAY_DEFINITION | CONSTRAINED_ARRAY_DEFINITION
-- UNCONSTRAINED_ARRAY_DEFINITION ::=
-- array (INDEX_SUBTYPE_DEFINITION {, INDEX_SUBTYPE_DEFINITION}) of
-- COMPONENT_DEFINITION
-- INDEX_SUBTYPE_DEFINITION ::= SUBTYPE_MARK range <>
-- CONSTRAINED_ARRAY_DEFINITION ::=
-- array (DISCRETE_SUBTYPE_DEFINITION {, DISCRETE_SUBTYPE_DEFINITION}) of
-- COMPONENT_DEFINITION
-- DISCRETE_SUBTYPE_DEFINITION ::=
-- DISCRETE_SUBTYPE_INDICATION | RANGE
-- COMPONENT_DEFINITION ::= [aliased] SUBTYPE_INDICATION
-- The caller has checked that the initial token is ARRAY
-- Error recovery: can raise Error_Resync
function P_Array_Type_Definition return Node_Id is
Array_Loc : Source_Ptr;
CompDef_Node : Node_Id;
Def_Node : Node_Id;
Subs_List : List_Id;
Scan_State : Saved_Scan_State;
begin
Array_Loc := Token_Ptr;
Scan; -- past ARRAY
Subs_List := New_List;
T_Left_Paren;
-- It's quite tricky to disentangle these two possibilities, so we do
-- a prescan to determine which case we have and then reset the scan.
-- The prescan skips past possible subtype mark tokens.
Save_Scan_State (Scan_State); -- just after paren
while Token in Token_Class_Desig or else
Token = Tok_Dot or else
Token = Tok_Apostrophe -- because of 'BASE, 'CLASS
loop
Scan;
end loop;
-- If we end up on RANGE <> then we have the unconstrained case. We
-- will also allow the RANGE to be omitted, just to improve error
-- handling for a case like array (integer <>) of integer;
Scan; -- past possible RANGE or <>
if (Prev_Token = Tok_Range and then Token = Tok_Box) or else
Prev_Token = Tok_Box
then
Def_Node := New_Node (N_Unconstrained_Array_Definition, Array_Loc);
Restore_Scan_State (Scan_State); -- to first subtype mark
loop
Append (P_Subtype_Mark_Resync, Subs_List);
T_Range;
T_Box;
exit when Token = Tok_Right_Paren or else Token = Tok_Of;
T_Comma;
end loop;
Set_Subtype_Marks (Def_Node, Subs_List);
else
Def_Node := New_Node (N_Constrained_Array_Definition, Array_Loc);
Restore_Scan_State (Scan_State); -- to first discrete range
loop
Append (P_Discrete_Subtype_Definition, Subs_List);
exit when not Comma_Present;
end loop;
Set_Discrete_Subtype_Definitions (Def_Node, Subs_List);
end if;
T_Right_Paren;
T_Of;
CompDef_Node := New_Node (N_Component_Definition, Token_Ptr);
if Token = Tok_Aliased then
Set_Aliased_Present (CompDef_Node, True);
Scan; -- past ALIASED
end if;
Set_Subtype_Indication (CompDef_Node, P_Subtype_Indication);
Set_Component_Definition (Def_Node, CompDef_Node);
return Def_Node;
end P_Array_Type_Definition;
-----------------------------------------
-- 3.6 Unconstrained Array Definition --
-----------------------------------------
-- Parsed by P_Array_Type_Definition (3.6)
---------------------------------------
-- 3.6 Constrained Array Definition --
---------------------------------------
-- Parsed by P_Array_Type_Definition (3.6)
--------------------------------------
-- 3.6 Discrete Subtype Definition --
--------------------------------------
-- DISCRETE_SUBTYPE_DEFINITION ::=
-- discrete_SUBTYPE_INDICATION | RANGE
-- Note: the discrete subtype definition appearing in a constrained
-- array definition is parsed by P_Array_Type_Definition (3.6)
-- Error recovery: cannot raise Error_Resync
function P_Discrete_Subtype_Definition return Node_Id is
begin
-- The syntax of a discrete subtype definition is identical to that
-- of a discrete range, so we simply share the same parsing code.
return P_Discrete_Range;
end P_Discrete_Subtype_Definition;
-------------------------------
-- 3.6 Component Definition --
-------------------------------
-- For the array case, parsed by P_Array_Type_Definition (3.6)
-- For the record case, parsed by P_Component_Declaration (3.8)
-----------------------------
-- 3.6.1 Index Constraint --
-----------------------------
-- Parsed by P_Index_Or_Discriminant_Constraint (3.7.1)
---------------------------
-- 3.6.1 Discrete Range --
---------------------------
-- DISCRETE_RANGE ::= discrete_SUBTYPE_INDICATION | RANGE
-- The possible forms for a discrete range are:
-- Subtype_Mark (SUBTYPE_INDICATION, 3.2.2)
-- Subtype_Mark range Range (SUBTYPE_INDICATION, 3.2.2)
-- Range_Attribute (RANGE, 3.5)
-- Simple_Expression .. Simple_Expression (RANGE, 3.5)
-- Error recovery: cannot raise Error_Resync
function P_Discrete_Range return Node_Id is
Expr_Node : Node_Id;
Range_Node : Node_Id;
begin
Expr_Node := P_Simple_Expression_Or_Range_Attribute;
if Expr_Form = EF_Range_Attr then
return Expr_Node;
elsif Token = Tok_Range then
if Expr_Form /= EF_Simple_Name then
Error_Msg_SC ("range must be preceded by subtype mark");
end if;
return P_Subtype_Indication (Expr_Node);
-- Check Expression .. Expression case
elsif Token = Tok_Dot_Dot then
Range_Node := New_Node (N_Range, Token_Ptr);
Set_Low_Bound (Range_Node, Expr_Node);
Scan; -- past ..
Expr_Node := P_Expression;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Range_Node, Expr_Node);
return Range_Node;
-- Otherwise we must have a subtype mark
elsif Expr_Form = EF_Simple_Name then
return Expr_Node;
-- If incorrect, complain that we expect ..
else
T_Dot_Dot;
return Expr_Node;
end if;
end P_Discrete_Range;
----------------------------
-- 3.7 Discriminant Part --
----------------------------
-- DISCRIMINANT_PART ::=
-- UNKNOWN_DISCRIMINANT_PART
-- | KNOWN_DISCRIMINANT_PART
-- A discriminant part is parsed by P_Known_Discriminant_Part_Opt (3.7)
-- or P_Unknown_Discriminant_Part (3.7), since we know which we want.
------------------------------------
-- 3.7 Unknown Discriminant Part --
------------------------------------
-- UNKNOWN_DISCRIMINANT_PART ::= (<>)
-- If no unknown discriminant part is present, then False is returned,
-- otherwise the unknown discriminant is scanned out and True is returned.
-- Error recovery: cannot raise Error_Resync
function P_Unknown_Discriminant_Part_Opt return Boolean is
Scan_State : Saved_Scan_State;
begin
if Token /= Tok_Left_Paren then
return False;
else
Save_Scan_State (Scan_State);
Scan; -- past the left paren
if Token = Tok_Box then
if Ada_83 then
Error_Msg_SC ("(Ada 83) unknown discriminant not allowed!");
end if;
Scan; -- past the box
T_Right_Paren; -- must be followed by right paren
return True;
else
Restore_Scan_State (Scan_State);
return False;
end if;
end if;
end P_Unknown_Discriminant_Part_Opt;
----------------------------------
-- 3.7 Known Discriminant Part --
----------------------------------
-- KNOWN_DISCRIMINANT_PART ::=
-- (DISCRIMINANT_SPECIFICATION {; DISCRIMINANT_SPECIFICATION})
-- DISCRIMINANT_SPECIFICATION ::=
-- DEFINING_IDENTIFIER_LIST : SUBTYPE_MARK
-- [:= DEFAULT_EXPRESSION]
-- | DEFINING_IDENTIFIER_LIST : ACCESS_DEFINITION
-- [:= DEFAULT_EXPRESSION]
-- If no known discriminant part is present, then No_List is returned
-- Error recovery: cannot raise Error_Resync
function P_Known_Discriminant_Part_Opt return List_Id is
Specification_Node : Node_Id;
Specification_List : List_Id;
Ident_Sloc : Source_Ptr;
Scan_State : Saved_Scan_State;
Num_Idents : Nat;
Ident : Nat;
Idents : array (Int range 1 .. 4096) of Entity_Id;
-- This array holds the list of defining identifiers. The upper bound
-- of 4096 is intended to be essentially infinite, and we do not even
-- bother to check for it being exceeded.
begin
if Token = Tok_Left_Paren then
Specification_List := New_List;
Scan; -- past (
P_Pragmas_Misplaced;
Specification_Loop : loop
Ident_Sloc := Token_Ptr;
Idents (1) := P_Defining_Identifier (C_Comma_Colon);
Num_Idents := 1;
while Comma_Present loop
Num_Idents := Num_Idents + 1;
Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
end loop;
T_Colon;
-- If there are multiple identifiers, we repeatedly scan the
-- type and initialization expression information by resetting
-- the scan pointer (so that we get completely separate trees
-- for each occurrence).
if Num_Idents > 1 then
Save_Scan_State (Scan_State);
end if;
-- Loop through defining identifiers in list
Ident := 1;
Ident_Loop : loop
Specification_Node :=
New_Node (N_Discriminant_Specification, Ident_Sloc);
Set_Defining_Identifier (Specification_Node, Idents (Ident));
if Token = Tok_Access then
if Ada_83 then
Error_Msg_SC
("(Ada 83) access discriminant not allowed!");
end if;
Set_Discriminant_Type
(Specification_Node, P_Access_Definition);
else
Set_Discriminant_Type
(Specification_Node, P_Subtype_Mark);
No_Constraint;
end if;
Set_Expression
(Specification_Node, Init_Expr_Opt (True));
if Ident > 1 then
Set_Prev_Ids (Specification_Node, True);
end if;
if Ident < Num_Idents then
Set_More_Ids (Specification_Node, True);
end if;
Append (Specification_Node, Specification_List);
exit Ident_Loop when Ident = Num_Idents;
Ident := Ident + 1;
Restore_Scan_State (Scan_State);
end loop Ident_Loop;
exit Specification_Loop when Token /= Tok_Semicolon;
Scan; -- past ;
P_Pragmas_Misplaced;
end loop Specification_Loop;
T_Right_Paren;
return Specification_List;
else
return No_List;
end if;
end P_Known_Discriminant_Part_Opt;
-------------------------------------
-- 3.7 DIscriminant Specification --
-------------------------------------
-- Parsed by P_Known_Discriminant_Part_Opt (3.7)
-----------------------------
-- 3.7 Default Expression --
-----------------------------
-- Always parsed (simply as an Expression) by the parent construct
------------------------------------
-- 3.7.1 Discriminant Constraint --
------------------------------------
-- Parsed by P_Index_Or_Discriminant_Constraint (3.7.1)
--------------------------------------------------------
-- 3.7.1 Index or Discriminant Constraint (also 3.6) --
--------------------------------------------------------
-- DISCRIMINANT_CONSTRAINT ::=
-- (DISCRIMINANT_ASSOCIATION {, DISCRIMINANT_ASSOCIATION})
-- DISCRIMINANT_ASSOCIATION ::=
-- [discriminant_SELECTOR_NAME {| discriminant_SELECTOR_NAME} =>]
-- EXPRESSION
-- This routine parses either an index or a discriminant constraint. As
-- is clear from the above grammar, it is often possible to clearly
-- determine which of the two possibilities we have, but there are
-- cases (those in which we have a series of expressions of the same
-- syntactic form as subtype indications), where we cannot tell. Since
-- this means that in any case the semantic phase has to distinguish
-- between the two, there is not much point in the parser trying to
-- distinguish even those cases where the difference is clear. In any
-- case, if we have a situation like:
-- (A => 123, 235 .. 500)
-- it is not clear which of the two items is the wrong one, better to
-- let the semantic phase give a clear message. Consequently, this
-- routine in general returns a list of items which can be either
-- discrete ranges or discriminant associations.
-- The caller has checked that the initial token is a left paren
-- Error recovery: can raise Error_Resync
function P_Index_Or_Discriminant_Constraint return Node_Id is
Scan_State : Saved_Scan_State;
Constr_Node : Node_Id;
Constr_List : List_Id;
Expr_Node : Node_Id;
Result_Node : Node_Id;
begin
Result_Node := New_Node (N_Index_Or_Discriminant_Constraint, Token_Ptr);
Scan; -- past (
Constr_List := New_List;
Set_Constraints (Result_Node, Constr_List);
-- The two syntactic forms are a little mixed up, so what we are doing
-- here is looking at the first entry to determine which case we have
-- A discriminant constraint is a list of discriminant associations,
-- which have one of the following possible forms:
-- Expression
-- Id => Expression
-- Id | Id | .. | Id => Expression
-- An index constraint is a list of discrete ranges which have one
-- of the following possible forms:
-- Subtype_Mark
-- Subtype_Mark range Range
-- Range_Attribute
-- Simple_Expression .. Simple_Expression
-- Loop through discriminants in list
loop
-- Check cases of Id => Expression or Id | Id => Expression
if Token = Tok_Identifier then
Save_Scan_State (Scan_State); -- at Id
Scan; -- past Id
if Token = Tok_Arrow or else Token = Tok_Vertical_Bar then
Restore_Scan_State (Scan_State); -- to Id
Append (P_Discriminant_Association, Constr_List);
goto Loop_Continue;
else
Restore_Scan_State (Scan_State); -- to Id
end if;
end if;
-- Otherwise scan out an expression and see what we have got
Expr_Node := P_Expression_Or_Range_Attribute;
if Expr_Form = EF_Range_Attr then
Append (Expr_Node, Constr_List);
elsif Token = Tok_Range then
if Expr_Form /= EF_Simple_Name then
Error_Msg_SC ("subtype mark required before RANGE");
end if;
Append (P_Subtype_Indication (Expr_Node), Constr_List);
goto Loop_Continue;
-- Check Simple_Expression .. Simple_Expression case
elsif Token = Tok_Dot_Dot then
Check_Simple_Expression (Expr_Node);
Constr_Node := New_Node (N_Range, Token_Ptr);
Set_Low_Bound (Constr_Node, Expr_Node);
Scan; -- past ..
Expr_Node := P_Expression;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Constr_Node, Expr_Node);
Append (Constr_Node, Constr_List);
goto Loop_Continue;
-- Case of an expression which could be either form
else
Append (Expr_Node, Constr_List);
goto Loop_Continue;
end if;
-- Here with a single entry scanned
<<Loop_Continue>>
exit when not Comma_Present;
end loop;
T_Right_Paren;
return Result_Node;
end P_Index_Or_Discriminant_Constraint;
-------------------------------------
-- 3.7.1 Discriminant Association --
-------------------------------------
-- DISCRIMINANT_ASSOCIATION ::=
-- [discriminant_SELECTOR_NAME {| discriminant_SELECTOR_NAME} =>]
-- EXPRESSION
-- This routine is used only when the name list is present and the caller
-- has already checked this (by scanning ahead and repositioning the
-- scan).
-- Error_Recovery: cannot raise Error_Resync;
function P_Discriminant_Association return Node_Id is
Discr_Node : Node_Id;
Names_List : List_Id;
Ident_Sloc : Source_Ptr;
begin
Ident_Sloc := Token_Ptr;
Names_List := New_List;
loop
Append (P_Identifier (C_Vertical_Bar_Arrow), Names_List);
exit when Token /= Tok_Vertical_Bar;
Scan; -- past |
end loop;
Discr_Node := New_Node (N_Discriminant_Association, Ident_Sloc);
Set_Selector_Names (Discr_Node, Names_List);
TF_Arrow;
Set_Expression (Discr_Node, P_Expression);
return Discr_Node;
end P_Discriminant_Association;
---------------------------------
-- 3.8 Record Type Definition --
---------------------------------
-- RECORD_TYPE_DEFINITION ::=
-- [[abstract] tagged] [limited] RECORD_DEFINITION
-- There is no node in the tree for a record type definition. Instead
-- a record definition node appears, with possible Abstract_Present,
-- Tagged_Present, and Limited_Present flags set appropriately.
----------------------------
-- 3.8 Record Definition --
----------------------------
-- RECORD_DEFINITION ::=
-- record
-- COMPONENT_LIST
-- end record
-- | null record
-- Note: in the case where a record definition node is used to represent
-- a record type definition, the caller sets the Tagged_Present and
-- Limited_Present flags in the resulting N_Record_Definition node as
-- required.
-- Note that the RECORD token at the start may be missing in certain
-- error situations, so this function is expected to post the error
-- Error recovery: can raise Error_Resync
function P_Record_Definition return Node_Id is
Rec_Node : Node_Id;
begin
Rec_Node := New_Node (N_Record_Definition, Token_Ptr);
-- Null record case
if Token = Tok_Null then
Scan; -- past NULL
T_Record;
Set_Null_Present (Rec_Node, True);
-- Case starting with RECORD keyword. Build scope stack entry. For the
-- column, we use the first non-blank character on the line, to deal
-- with situations such as:
-- type X is record
-- ...
-- end record;
-- which is not official RM indentation, but is not uncommon usage
else
Push_Scope_Stack;
Scope.Table (Scope.Last).Etyp := E_Record;
Scope.Table (Scope.Last).Ecol := Start_Column;
Scope.Table (Scope.Last).Sloc := Token_Ptr;
Scope.Table (Scope.Last).Labl := Error;
Scope.Table (Scope.Last).Junk := (Token /= Tok_Record);
T_Record;
Set_Component_List (Rec_Node, P_Component_List);
loop
exit when Check_End;
Discard_Junk_Node (P_Component_List);
end loop;
end if;
return Rec_Node;
end P_Record_Definition;
-------------------------
-- 3.8 Component List --
-------------------------
-- COMPONENT_LIST ::=
-- COMPONENT_ITEM {COMPONENT_ITEM}
-- | {COMPONENT_ITEM} VARIANT_PART
-- | null;
-- Error recovery: cannot raise Error_Resync
function P_Component_List return Node_Id is
Component_List_Node : Node_Id;
Decls_List : List_Id;
Scan_State : Saved_Scan_State;
begin
Component_List_Node := New_Node (N_Component_List, Token_Ptr);
Decls_List := New_List;
if Token = Tok_Null then
Scan; -- past NULL
TF_Semicolon;
P_Pragmas_Opt (Decls_List);
Set_Null_Present (Component_List_Node, True);
return Component_List_Node;
else
P_Pragmas_Opt (Decls_List);
if Token /= Tok_Case then
Component_Scan_Loop : loop
P_Component_Items (Decls_List);
P_Pragmas_Opt (Decls_List);
exit Component_Scan_Loop when Token = Tok_End
or else Token = Tok_Case
or else Token = Tok_When;
-- We are done if we do not have an identifier. However, if
-- we have a misspelled reserved identifier that is in a column
-- to the right of the record definition, we will treat it as
-- an identifier. It turns out to be too dangerous in practice
-- to accept such a mis-spelled identifier which does not have
-- this additional clue that confirms the incorrect spelling.
if Token /= Tok_Identifier then
if Start_Column > Scope.Table (Scope.Last).Ecol
and then Is_Reserved_Identifier
then
Save_Scan_State (Scan_State); -- at reserved id
Scan; -- possible reserved id
if Token = Tok_Comma or else Token = Tok_Colon then
Restore_Scan_State (Scan_State);
Scan_Reserved_Identifier (Force_Msg => True);
-- Note reserved identifier used as field name after
-- all because not followed by colon or comma
else
Restore_Scan_State (Scan_State);
exit Component_Scan_Loop;
end if;
-- Non-identifier that definitely was not reserved id
else
exit Component_Scan_Loop;
end if;
end if;
end loop Component_Scan_Loop;
end if;
if Token = Tok_Case then
Set_Variant_Part (Component_List_Node, P_Variant_Part);
-- Check for junk after variant part
if Token = Tok_Identifier then
Save_Scan_State (Scan_State);
Scan; -- past identifier
if Token = Tok_Colon then
Restore_Scan_State (Scan_State);
Error_Msg_SC ("component may not follow variant part");
Discard_Junk_Node (P_Component_List);
elsif Token = Tok_Case then
Restore_Scan_State (Scan_State);
Error_Msg_SC ("only one variant part allowed in a record");
Discard_Junk_Node (P_Component_List);
else
Restore_Scan_State (Scan_State);
end if;
end if;
end if;
end if;
Set_Component_Items (Component_List_Node, Decls_List);
return Component_List_Node;
end P_Component_List;
-------------------------
-- 3.8 Component Item --
-------------------------
-- COMPONENT_ITEM ::= COMPONENT_DECLARATION | REPRESENTATION_CLAUSE
-- COMPONENT_DECLARATION ::=
-- DEFINING_IDENTIFIER_LIST : COMPONENT_DEFINITION
-- [:= DEFAULT_EXPRESSION];
-- COMPONENT_DEFINITION ::= [aliased] SUBTYPE_INDICATION
-- Error recovery: cannot raise Error_Resync, if an error occurs,
-- the scan is positioned past the following semicolon.
-- Note: we do not yet allow representation clauses to appear as component
-- items, do we need to add this capability sometime in the future ???
procedure P_Component_Items (Decls : List_Id) is
CompDef_Node : Node_Id;
Decl_Node : Node_Id;
Scan_State : Saved_Scan_State;
Num_Idents : Nat;
Ident : Nat;
Ident_Sloc : Source_Ptr;
Idents : array (Int range 1 .. 4096) of Entity_Id;
-- This array holds the list of defining identifiers. The upper bound
-- of 4096 is intended to be essentially infinite, and we do not even
-- bother to check for it being exceeded.
begin
if Token /= Tok_Identifier then
Error_Msg_SC ("component declaration expected");
Resync_Past_Semicolon;
return;
end if;
Ident_Sloc := Token_Ptr;
Idents (1) := P_Defining_Identifier (C_Comma_Colon);
Num_Idents := 1;
while Comma_Present loop
Num_Idents := Num_Idents + 1;
Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
end loop;
T_Colon;
-- If there are multiple identifiers, we repeatedly scan the
-- type and initialization expression information by resetting
-- the scan pointer (so that we get completely separate trees
-- for each occurrence).
if Num_Idents > 1 then
Save_Scan_State (Scan_State);
end if;
-- Loop through defining identifiers in list
Ident := 1;
Ident_Loop : loop
-- The following block is present to catch Error_Resync
-- which causes the parse to be reset past the semicolon
begin
Decl_Node := New_Node (N_Component_Declaration, Ident_Sloc);
Set_Defining_Identifier (Decl_Node, Idents (Ident));
if Token = Tok_Constant then
Error_Msg_SC ("constant components are not permitted");
Scan;
end if;
CompDef_Node := New_Node (N_Component_Definition, Token_Ptr);
if Token_Name = Name_Aliased then
Check_95_Keyword (Tok_Aliased, Tok_Identifier);
end if;
if Token = Tok_Aliased then
Scan; -- past ALIASED
Set_Aliased_Present (CompDef_Node, True);
end if;
if Token = Tok_Array then
Error_Msg_SC ("anonymous arrays not allowed as components");
raise Error_Resync;
end if;
Set_Subtype_Indication (CompDef_Node, P_Subtype_Indication);
Set_Component_Definition (Decl_Node, CompDef_Node);
Set_Expression (Decl_Node, Init_Expr_Opt);
if Ident > 1 then
Set_Prev_Ids (Decl_Node, True);
end if;
if Ident < Num_Idents then
Set_More_Ids (Decl_Node, True);
end if;
Append (Decl_Node, Decls);
exception
when Error_Resync =>
if Token /= Tok_End then
Resync_Past_Semicolon;
end if;
end;
exit Ident_Loop when Ident = Num_Idents;
Ident := Ident + 1;
Restore_Scan_State (Scan_State);
end loop Ident_Loop;
TF_Semicolon;
end P_Component_Items;
--------------------------------
-- 3.8 Component Declaration --
--------------------------------
-- Parsed by P_Component_Items (3.8)
-------------------------
-- 3.8.1 Variant Part --
-------------------------
-- VARIANT_PART ::=
-- case discriminant_DIRECT_NAME is
-- VARIANT
-- {VARIANT}
-- end case;
-- The caller has checked that the initial token is CASE
-- Error recovery: cannot raise Error_Resync
function P_Variant_Part return Node_Id is
Variant_Part_Node : Node_Id;
Variants_List : List_Id;
Case_Node : Node_Id;
begin
Variant_Part_Node := New_Node (N_Variant_Part, Token_Ptr);
Push_Scope_Stack;
Scope.Table (Scope.Last).Etyp := E_Case;
Scope.Table (Scope.Last).Sloc := Token_Ptr;
Scope.Table (Scope.Last).Ecol := Start_Column;
Scan; -- past CASE
Case_Node := P_Expression;
Set_Name (Variant_Part_Node, Case_Node);
if Nkind (Case_Node) /= N_Identifier then
Set_Name (Variant_Part_Node, Error);
Error_Msg ("discriminant name expected", Sloc (Case_Node));
end if;
TF_Is;
Variants_List := New_List;
P_Pragmas_Opt (Variants_List);
-- Test missing variant
if Token = Tok_End then
Error_Msg_BC ("WHEN expected (must have at least one variant)");
else
Append (P_Variant, Variants_List);
end if;
-- Loop through variants, note that we allow if in place of when,
-- this error will be detected and handled in P_Variant.
loop
P_Pragmas_Opt (Variants_List);
if Token /= Tok_When
and then Token /= Tok_If
and then Token /= Tok_Others
then
exit when Check_End;
end if;
Append (P_Variant, Variants_List);
end loop;
Set_Variants (Variant_Part_Node, Variants_List);
return Variant_Part_Node;
end P_Variant_Part;
--------------------
-- 3.8.1 Variant --
--------------------
-- VARIANT ::=
-- when DISCRETE_CHOICE_LIST =>
-- COMPONENT_LIST
-- Error recovery: cannot raise Error_Resync
-- The initial token on entry is either WHEN, IF or OTHERS
function P_Variant return Node_Id is
Variant_Node : Node_Id;
begin
-- Special check to recover nicely from use of IF in place of WHEN
if Token = Tok_If then
T_When;
Scan; -- past IF
else
T_When;
end if;
Variant_Node := New_Node (N_Variant, Prev_Token_Ptr);
Set_Discrete_Choices (Variant_Node, P_Discrete_Choice_List);
TF_Arrow;
Set_Component_List (Variant_Node, P_Component_List);
return Variant_Node;
end P_Variant;
---------------------------------
-- 3.8.1 Discrete Choice List --
---------------------------------
-- DISCRETE_CHOICE_LIST ::= DISCRETE_CHOICE {| DISCRETE_CHOICE}
-- DISCRETE_CHOICE ::= EXPRESSION | DISCRETE_RANGE | others
-- Note: in Ada 83, the expression must be a simple expression
-- Error recovery: cannot raise Error_Resync
function P_Discrete_Choice_List return List_Id is
Choices : List_Id;
Expr_Node : Node_Id;
Choice_Node : Node_Id;
begin
Choices := New_List;
loop
if Token = Tok_Others then
Append (New_Node (N_Others_Choice, Token_Ptr), Choices);
Scan; -- past OTHERS
else
begin
Expr_Node := No_Right_Paren (P_Expression_Or_Range_Attribute);
if Token = Tok_Colon
and then Nkind (Expr_Node) = N_Identifier
then
Error_Msg_SP ("label not permitted in this context");
Scan; -- past colon
elsif Expr_Form = EF_Range_Attr then
Append (Expr_Node, Choices);
elsif Token = Tok_Dot_Dot then
Check_Simple_Expression (Expr_Node);
Choice_Node := New_Node (N_Range, Token_Ptr);
Set_Low_Bound (Choice_Node, Expr_Node);
Scan; -- past ..
Expr_Node := P_Expression_No_Right_Paren;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Choice_Node, Expr_Node);
Append (Choice_Node, Choices);
elsif Expr_Form = EF_Simple_Name then
if Token = Tok_Range then
Append (P_Subtype_Indication (Expr_Node), Choices);
elsif Token in Token_Class_Consk then
Error_Msg_SC
("the only constraint allowed here " &
"is a range constraint");
Discard_Junk_Node (P_Constraint_Opt);
Append (Expr_Node, Choices);
else
Append (Expr_Node, Choices);
end if;
else
Check_Simple_Expression_In_Ada_83 (Expr_Node);
Append (Expr_Node, Choices);
end if;
exception
when Error_Resync =>
Resync_Choice;
return Error_List;
end;
end if;
if Token = Tok_Comma then
Error_Msg_SC (""","" should be ""'|""");
else
exit when Token /= Tok_Vertical_Bar;
end if;
Scan; -- past | or comma
end loop;
return Choices;
end P_Discrete_Choice_List;
----------------------------
-- 3.8.1 Discrete Choice --
----------------------------
-- Parsed by P_Discrete_Choice_List (3.8.1)
----------------------------------
-- 3.9.1 Record Extension Part --
----------------------------------
-- RECORD_EXTENSION_PART ::= with RECORD_DEFINITION
-- Parsed by P_Derived_Type_Def_Or_Private_Ext_Decl (3.4)
----------------------------------
-- 3.10 Access Type Definition --
----------------------------------
-- ACCESS_TYPE_DEFINITION ::=
-- ACCESS_TO_OBJECT_DEFINITION
-- | ACCESS_TO_SUBPROGRAM_DEFINITION
-- ACCESS_TO_OBJECT_DEFINITION ::=
-- access [GENERAL_ACCESS_MODIFIER] SUBTYPE_INDICATION
-- GENERAL_ACCESS_MODIFIER ::= all | constant
-- ACCESS_TO_SUBPROGRAM_DEFINITION
-- access [protected] procedure PARAMETER_PROFILE
-- | access [protected] function PARAMETER_AND_RESULT_PROFILE
-- PARAMETER_PROFILE ::= [FORMAL_PART]
-- PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] RETURN SUBTYPE_MARK
-- The caller has checked that the initial token is ACCESS
-- Error recovery: can raise Error_Resync
function P_Access_Type_Definition return Node_Id is
Prot_Flag : Boolean;
Access_Loc : Source_Ptr;
Type_Def_Node : Node_Id;
procedure Check_Junk_Subprogram_Name;
-- Used in access to subprogram definition cases to check for an
-- identifier or operator symbol that does not belong.
procedure Check_Junk_Subprogram_Name is
Saved_State : Saved_Scan_State;
begin
if Token = Tok_Identifier or else Token = Tok_Operator_Symbol then
Save_Scan_State (Saved_State);
Scan; -- past possible junk subprogram name
if Token = Tok_Left_Paren or else Token = Tok_Semicolon then
Error_Msg_SP ("unexpected subprogram name ignored");
return;
else
Restore_Scan_State (Saved_State);
end if;
end if;
end Check_Junk_Subprogram_Name;
-- Start of processing for P_Access_Type_Definition
begin
Access_Loc := Token_Ptr;
Scan; -- past ACCESS
if Token_Name = Name_Protected then
Check_95_Keyword (Tok_Protected, Tok_Procedure);
Check_95_Keyword (Tok_Protected, Tok_Function);
end if;
Prot_Flag := (Token = Tok_Protected);
if Prot_Flag then
Scan; -- past PROTECTED
if Token /= Tok_Procedure and then Token /= Tok_Function then
Error_Msg_SC ("FUNCTION or PROCEDURE expected");
end if;
end if;
if Token = Tok_Procedure then
if Ada_83 then
Error_Msg_SC ("(Ada 83) access to procedure not allowed!");
end if;
Type_Def_Node := New_Node (N_Access_Procedure_Definition, Access_Loc);
Scan; -- past PROCEDURE
Check_Junk_Subprogram_Name;
Set_Parameter_Specifications (Type_Def_Node, P_Parameter_Profile);
Set_Protected_Present (Type_Def_Node, Prot_Flag);
elsif Token = Tok_Function then
if Ada_83 then
Error_Msg_SC ("(Ada 83) access to function not allowed!");
end if;
Type_Def_Node := New_Node (N_Access_Function_Definition, Access_Loc);
Scan; -- past FUNCTION
Check_Junk_Subprogram_Name;
Set_Parameter_Specifications (Type_Def_Node, P_Parameter_Profile);
Set_Protected_Present (Type_Def_Node, Prot_Flag);
TF_Return;
Set_Subtype_Mark (Type_Def_Node, P_Subtype_Mark);
No_Constraint;
else
Type_Def_Node :=
New_Node (N_Access_To_Object_Definition, Access_Loc);
if Token = Tok_All or else Token = Tok_Constant then
if Ada_83 then
Error_Msg_SC ("(Ada 83) access modifier not allowed!");
end if;
if Token = Tok_All then
Set_All_Present (Type_Def_Node, True);
else
Set_Constant_Present (Type_Def_Node, True);
end if;
Scan; -- past ALL or CONSTANT
end if;
Set_Subtype_Indication (Type_Def_Node, P_Subtype_Indication);
end if;
return Type_Def_Node;
end P_Access_Type_Definition;
---------------------------------------
-- 3.10 Access To Object Definition --
---------------------------------------
-- Parsed by P_Access_Type_Definition (3.10)
-----------------------------------
-- 3.10 General Access Modifier --
-----------------------------------
-- Parsed by P_Access_Type_Definition (3.10)
-------------------------------------------
-- 3.10 Access To Subprogram Definition --
-------------------------------------------
-- Parsed by P_Access_Type_Definition (3.10)
-----------------------------
-- 3.10 Access Definition --
-----------------------------
-- ACCESS_DEFINITION ::= access SUBTYPE_MARK
-- The caller has checked that the initial token is ACCESS
-- Error recovery: cannot raise Error_Resync
function P_Access_Definition return Node_Id is
Def_Node : Node_Id;
begin
Def_Node := New_Node (N_Access_Definition, Token_Ptr);
Scan; -- past ACCESS
Set_Subtype_Mark (Def_Node, P_Subtype_Mark);
No_Constraint;
return Def_Node;
end P_Access_Definition;
-----------------------------------------
-- 3.10.1 Incomplete Type Declaration --
-----------------------------------------
-- Parsed by P_Type_Declaration (3.2.1)
----------------------------
-- 3.11 Declarative Part --
----------------------------
-- DECLARATIVE_PART ::= {DECLARATIVE_ITEM}
-- Error recovery: cannot raise Error_Resync (because P_Declarative_Items
-- handles errors, and returns cleanly after an error has occurred)
function P_Declarative_Part return List_Id is
Decls : List_Id;
Done : Boolean;
begin
-- Indicate no bad declarations detected yet. This will be reset by
-- P_Declarative_Items if a bad declaration is discovered.
Missing_Begin_Msg := No_Error_Msg;
-- Get rid of active SIS entry from outer scope. This means we will
-- miss some nested cases, but it doesn't seem worth the effort. See
-- discussion in Par for further details
SIS_Entry_Active := False;
Decls := New_List;
-- Loop to scan out the declarations
loop
P_Declarative_Items (Decls, Done, In_Spec => False);
exit when Done;
end loop;
-- Get rid of active SIS entry which is left set only if we scanned a
-- procedure declaration and have not found the body. We could give
-- an error message, but that really would be usurping the role of
-- semantic analysis (this really is a missing body case).
SIS_Entry_Active := False;
return Decls;
end P_Declarative_Part;
----------------------------
-- 3.11 Declarative Item --
----------------------------
-- DECLARATIVE_ITEM ::= BASIC_DECLARATIVE_ITEM | BODY
-- Can return Error if a junk declaration is found, or Empty if no
-- declaration is found (i.e. a token ending declarations, such as
-- BEGIN or END is encountered).
-- Error recovery: cannot raise Error_Resync. If an error resync occurs,
-- then the scan is set past the next semicolon and Error is returned.
procedure P_Declarative_Items
(Decls : List_Id;
Done : out Boolean;
In_Spec : Boolean)
is
Scan_State : Saved_Scan_State;
begin
if Style_Check then Style.Check_Indentation; end if;
case Token is
when Tok_Function =>
Check_Bad_Layout;
Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub), Decls);
Done := False;
when Tok_For =>
Check_Bad_Layout;
-- Check for loop (premature statement)
Save_Scan_State (Scan_State);
Scan; -- past FOR
if Token = Tok_Identifier then
Scan; -- past identifier
if Token = Tok_In then
Restore_Scan_State (Scan_State);
Statement_When_Declaration_Expected (Decls, Done, In_Spec);
return;
end if;
end if;
-- Not a loop, so must be rep clause
Restore_Scan_State (Scan_State);
Append (P_Representation_Clause, Decls);
Done := False;
when Tok_Generic =>
Check_Bad_Layout;
Append (P_Generic, Decls);
Done := False;
when Tok_Identifier =>
Check_Bad_Layout;
P_Identifier_Declarations (Decls, Done, In_Spec);
when Tok_Package =>
Check_Bad_Layout;
Append (P_Package (Pf_Decl_Gins_Pbod_Rnam_Stub), Decls);
Done := False;
when Tok_Pragma =>
Append (P_Pragma, Decls);
Done := False;
when Tok_Procedure =>
Check_Bad_Layout;
Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub), Decls);
Done := False;
when Tok_Protected =>
Check_Bad_Layout;
Scan; -- past PROTECTED
Append (P_Protected, Decls);
Done := False;
when Tok_Subtype =>
Check_Bad_Layout;
Append (P_Subtype_Declaration, Decls);
Done := False;
when Tok_Task =>
Check_Bad_Layout;
Scan; -- past TASK
Append (P_Task, Decls);
Done := False;
when Tok_Type =>
Check_Bad_Layout;
Append (P_Type_Declaration, Decls);
Done := False;
when Tok_Use =>
Check_Bad_Layout;
Append (P_Use_Clause, Decls);
Done := False;
when Tok_With =>
Check_Bad_Layout;
Error_Msg_SC ("WITH can only appear in context clause");
raise Error_Resync;
-- BEGIN terminates the scan of a sequence of declarations unless
-- there is a missing subprogram body, see section on handling
-- semicolon in place of IS. We only treat the begin as satisfying
-- the subprogram declaration if it falls in the expected column
-- or to its right.
when Tok_Begin =>
if SIS_Entry_Active and then Start_Column >= SIS_Ecol then
-- Here we have the case where a BEGIN is encountered during
-- declarations in a declarative part, or at the outer level,
-- and there is a subprogram declaration outstanding for which
-- no body has been supplied. This is the case where we assume
-- that the semicolon in the subprogram declaration should
-- really have been is. The active SIS entry describes the
-- subprogram declaration. On return the declaration has been
-- modified to become a body.
declare
Specification_Node : Node_Id;
Decl_Node : Node_Id;
Body_Node : Node_Id;
begin
-- First issue the error message. If we had a missing
-- semicolon in the declaration, then change the message
-- to <missing "is">
if SIS_Missing_Semicolon_Message /= No_Error_Msg then
Change_Error_Text -- Replace: "missing "";"" "
(SIS_Missing_Semicolon_Message, "missing ""is""");
-- Otherwise we saved the semicolon position, so complain
else
Error_Msg (""";"" should be IS", SIS_Semicolon_Sloc);
end if;
-- The next job is to fix up any declarations that occurred
-- between the procedure header and the BEGIN. These got
-- chained to the outer declarative region (immediately
-- after the procedure declaration) and they should be
-- chained to the subprogram itself, which is a body
-- rather than a spec.
Specification_Node := Specification (SIS_Declaration_Node);
Change_Node (SIS_Declaration_Node, N_Subprogram_Body);
Body_Node := SIS_Declaration_Node;
Set_Specification (Body_Node, Specification_Node);
Set_Declarations (Body_Node, New_List);
loop
Decl_Node := Remove_Next (Body_Node);
exit when Decl_Node = Empty;
Append (Decl_Node, Declarations (Body_Node));
end loop;
-- Now make the scope table entry for the Begin-End and
-- scan it out
Push_Scope_Stack;
Scope.Table (Scope.Last).Sloc := SIS_Sloc;
Scope.Table (Scope.Last).Etyp := E_Name;
Scope.Table (Scope.Last).Ecol := SIS_Ecol;
Scope.Table (Scope.Last).Labl := SIS_Labl;
Scope.Table (Scope.Last).Lreq := False;
SIS_Entry_Active := False;
Scan; -- past BEGIN
Set_Handled_Statement_Sequence (Body_Node,
P_Handled_Sequence_Of_Statements);
End_Statements (Handled_Statement_Sequence (Body_Node));
end;
Done := False;
else
Done := True;
end if;
-- Normally an END terminates the scan for basic declarative
-- items. The one exception is END RECORD, which is probably
-- left over from some other junk.
when Tok_End =>
Save_Scan_State (Scan_State); -- at END
Scan; -- past END
if Token = Tok_Record then
Error_Msg_SP ("no RECORD for this `end record`!");
Scan; -- past RECORD
TF_Semicolon;
else
Restore_Scan_State (Scan_State); -- to END
Done := True;
end if;
-- The following tokens which can only be the start of a statement
-- are considered to end a declarative part (i.e. we have a missing
-- BEGIN situation). We are fairly conservative in making this
-- judgment, because it is a real mess to go into statement mode
-- prematurely in response to a junk declaration.
when Tok_Abort |
Tok_Accept |
Tok_Declare |
Tok_Delay |
Tok_Exit |
Tok_Goto |
Tok_If |
Tok_Loop |
Tok_Null |
Tok_Requeue |
Tok_Select |
Tok_While =>
-- But before we decide that it's a statement, let's check for
-- a reserved word misused as an identifier.
if Is_Reserved_Identifier then
Save_Scan_State (Scan_State);
Scan; -- past the token
-- If reserved identifier not followed by colon or comma, then
-- this is most likely an assignment statement to the bad id.
if Token /= Tok_Colon and then Token /= Tok_Comma then
Restore_Scan_State (Scan_State);
Statement_When_Declaration_Expected (Decls, Done, In_Spec);
return;
-- Otherwise we have a declaration of the bad id
else
Restore_Scan_State (Scan_State);
Scan_Reserved_Identifier (Force_Msg => True);
P_Identifier_Declarations (Decls, Done, In_Spec);
end if;
-- If not reserved identifier, then it's definitely a statement
else
Statement_When_Declaration_Expected (Decls, Done, In_Spec);
return;
end if;
-- The token RETURN may well also signal a missing BEGIN situation,
-- however, we never let it end the declarative part, because it may
-- also be part of a half-baked function declaration.
when Tok_Return =>
Error_Msg_SC ("misplaced RETURN statement");
raise Error_Resync;
-- PRIVATE definitely terminates the declarations in a spec,
-- and is an error in a body.
when Tok_Private =>
if In_Spec then
Done := True;
else
Error_Msg_SC ("PRIVATE not allowed in body");
Scan; -- past PRIVATE
end if;
-- An end of file definitely terminates the declarations!
when Tok_EOF =>
Done := True;
-- The remaining tokens do not end the scan, but cannot start a
-- valid declaration, so we signal an error and resynchronize.
-- But first check for misuse of a reserved identifier.
when others =>
-- Here we check for a reserved identifier
if Is_Reserved_Identifier then
Save_Scan_State (Scan_State);
Scan; -- past the token
if Token /= Tok_Colon and then Token /= Tok_Comma then
Restore_Scan_State (Scan_State);
Set_Declaration_Expected;
raise Error_Resync;
else
Restore_Scan_State (Scan_State);
Scan_Reserved_Identifier (Force_Msg => True);
Check_Bad_Layout;
P_Identifier_Declarations (Decls, Done, In_Spec);
end if;
else
Set_Declaration_Expected;
raise Error_Resync;
end if;
end case;
-- To resynchronize after an error, we scan to the next semicolon and
-- return with Done = False, indicating that there may still be more
-- valid declarations to come.
exception
when Error_Resync =>
Resync_Past_Semicolon;
Done := False;
end P_Declarative_Items;
----------------------------------
-- 3.11 Basic Declarative Item --
----------------------------------
-- BASIC_DECLARATIVE_ITEM ::=
-- BASIC_DECLARATION | REPRESENTATION_CLAUSE | USE_CLAUSE
-- Scan zero or more basic declarative items
-- Error recovery: cannot raise Error_Resync. If an error is detected, then
-- the scan pointer is repositioned past the next semicolon, and the scan
-- for declarative items continues.
function P_Basic_Declarative_Items return List_Id is
Decl : Node_Id;
Decls : List_Id;
Kind : Node_Kind;
Done : Boolean;
begin
-- Indicate no bad declarations detected yet in the current context:
-- visible or private declarations of a package spec.
Missing_Begin_Msg := No_Error_Msg;
-- Get rid of active SIS entry from outer scope. This means we will
-- miss some nested cases, but it doesn't seem worth the effort. See
-- discussion in Par for further details
SIS_Entry_Active := False;
-- Loop to scan out declarations
Decls := New_List;
loop
P_Declarative_Items (Decls, Done, In_Spec => True);
exit when Done;
end loop;
-- Get rid of active SIS entry. This is set only if we have scanned a
-- procedure declaration and have not found the body. We could give
-- an error message, but that really would be usurping the role of
-- semantic analysis (this really is a case of a missing body).
SIS_Entry_Active := False;
-- Test for assorted illegal declarations not diagnosed elsewhere.
Decl := First (Decls);
while Present (Decl) loop
Kind := Nkind (Decl);
-- Test for body scanned, not acceptable as basic decl item
if Kind = N_Subprogram_Body or else
Kind = N_Package_Body or else
Kind = N_Task_Body or else
Kind = N_Protected_Body
then
Error_Msg
("proper body not allowed in package spec", Sloc (Decl));
-- Test for body stub scanned, not acceptable as basic decl item
elsif Kind in N_Body_Stub then
Error_Msg
("body stub not allowed in package spec", Sloc (Decl));
elsif Kind = N_Assignment_Statement then
Error_Msg
("assignment statement not allowed in package spec",
Sloc (Decl));
end if;
Next (Decl);
end loop;
return Decls;
end P_Basic_Declarative_Items;
----------------
-- 3.11 Body --
----------------
-- For proper body, see below
-- For body stub, see 10.1.3
-----------------------
-- 3.11 Proper Body --
-----------------------
-- Subprogram body is parsed by P_Subprogram (6.1)
-- Package body is parsed by P_Package (7.1)
-- Task body is parsed by P_Task (9.1)
-- Protected body is parsed by P_Protected (9.4)
------------------------------
-- Set_Declaration_Expected --
------------------------------
procedure Set_Declaration_Expected is
begin
Error_Msg_SC ("declaration expected");
if Missing_Begin_Msg = No_Error_Msg then
Missing_Begin_Msg := Get_Msg_Id;
end if;
end Set_Declaration_Expected;
----------------------
-- Skip_Declaration --
----------------------
procedure Skip_Declaration (S : List_Id) is
Dummy_Done : Boolean;
begin
P_Declarative_Items (S, Dummy_Done, False);
end Skip_Declaration;
-----------------------------------------
-- Statement_When_Declaration_Expected --
-----------------------------------------
procedure Statement_When_Declaration_Expected
(Decls : List_Id;
Done : out Boolean;
In_Spec : Boolean)
is
begin
-- Case of second occurrence of statement in one declaration sequence
if Missing_Begin_Msg /= No_Error_Msg then
-- In the procedure spec case, just ignore it, we only give one
-- message for the first occurrence, since otherwise we may get
-- horrible cascading if BODY was missing in the header line.
if In_Spec then
null;
-- In the declarative part case, take a second statement as a sure
-- sign that we really have a missing BEGIN, and end the declarative
-- part now. Note that the caller will fix up the first message to
-- say "missing BEGIN" so that's how the error will be signalled.
else
Done := True;
return;
end if;
-- Case of first occurrence of unexpected statement
else
-- If we are in a package spec, then give message of statement
-- not allowed in package spec. This message never gets changed.
if In_Spec then
Error_Msg_SC ("statement not allowed in package spec");
-- If in declarative part, then we give the message complaining
-- about finding a statement when a declaration is expected. This
-- gets changed to a complaint about a missing BEGIN if we later
-- find that no BEGIN is present.
else
Error_Msg_SC ("statement not allowed in declarative part");
end if;
-- Capture message Id. This is used for two purposes, first to
-- stop multiple messages, see test above, and second, to allow
-- the replacement of the message in the declarative part case.
Missing_Begin_Msg := Get_Msg_Id;
end if;
-- In all cases except the case in which we decided to terminate the
-- declaration sequence on a second error, we scan out the statement
-- and append it to the list of declarations (note that the semantics
-- can handle statements in a declaration list so if we proceed to
-- call the semantic phase, all will be (reasonably) well!
Append_List_To (Decls, P_Sequence_Of_Statements (SS_Unco));
-- Done is set to False, since we want to continue the scan of
-- declarations, hoping that this statement was a temporary glitch.
-- If we indeed are now in the statement part (i.e. this was a missing
-- BEGIN, then it's not terrible, we will simply keep calling this
-- procedure to process the statements one by one, and then finally
-- hit the missing BEGIN, which will clean up the error message.
Done := False;
end Statement_When_Declaration_Expected;
end Ch3;