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diff --git a/gcc/ada/scans.ads b/gcc/ada/scans.ads new file mode 100644 index 00000000000..b9d89e1f0ef --- /dev/null +++ b/gcc/ada/scans.ads @@ -0,0 +1,418 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S C A N S -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.32 $ +-- -- +-- Copyright (C) 1992-2000 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. -- +-- -- +-- As a special exception, if other files instantiate generics from this -- +-- unit, or you link this unit with other files to produce an executable, -- +-- this unit does not by itself cause the resulting executable to be -- +-- covered by the GNU General Public License. This exception does not -- +-- however invalidate any other reasons why the executable file might be -- +-- covered by the GNU Public License. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +with Types; use Types; +package Scans is + +-- The scanner maintains a current state in the global variables defined +-- in this package. The call to the Scan routine advances this state to +-- the next token. The state is initialized by the call to one of the +-- initialization routines in Sinput. + + -- The following type is used to identify token types returned by Scan. + -- The class column in this table indicates the token classes which + -- apply to the token, as defined by subsquent subtype declarations. + + -- Note: the coding in SCN depends on the fact that the first entry in + -- this type declaration is *not* for a reserved word. For details on + -- why there is this requirement, see Scn.Initialize_Scanner. + + type Token_Type is ( + + -- Token name Token type Class(es) + + Tok_Integer_Literal, -- numeric lit Literal, Lit_Or_Name + + Tok_Real_Literal, -- numeric lit Literal, Lit_Or_Name + + Tok_String_Literal, -- string lit Literal. Lit_Or_Name + + Tok_Char_Literal, -- char lit Name, Literal. Lit_Or_Name + + Tok_Operator_Symbol, -- op symbol Name, Literal, Lit_Or_Name, Desig + + Tok_Identifier, -- identifer Name, Lit_Or_Name, Desig + + Tok_Double_Asterisk, -- ** + + Tok_Ampersand, -- & Binary_Addop + Tok_Minus, -- - Binary_Addop, Unary_Addop + Tok_Plus, -- + Binary_Addop, Unary_Addop + + Tok_Asterisk, -- * Mulop + Tok_Mod, -- MOD Mulop + Tok_Rem, -- REM Mulop + Tok_Slash, -- / Mulop + + Tok_New, -- NEW + + Tok_Abs, -- ABS + Tok_Others, -- OTHERS + Tok_Null, -- NULL + + Tok_Dot, -- . Namext + Tok_Apostrophe, -- ' Namext + + Tok_Left_Paren, -- ( Namext, Consk + + Tok_Delta, -- DELTA Atkwd, Sterm, Consk + Tok_Digits, -- DIGITS Atkwd, Sterm, Consk + Tok_Range, -- RANGE Atkwd, Sterm, Consk + + Tok_Right_Paren, -- ) Sterm + Tok_Comma, -- , Sterm + + Tok_And, -- AND Logop, Sterm + Tok_Or, -- OR Logop, Sterm + Tok_Xor, -- XOR Logop, Sterm + + Tok_Less, -- < Relop, Sterm + Tok_Equal, -- = Relop, Sterm + Tok_Greater, -- > Relop, Sterm + Tok_Not_Equal, -- /= Relop, Sterm + Tok_Greater_Equal, -- >= Relop, Sterm + Tok_Less_Equal, -- <= Relop, Sterm + + Tok_In, -- IN Relop, Sterm + Tok_Not, -- NOT Relop, Sterm + + Tok_Box, -- <> Relop, Eterm, Sterm + Tok_Colon_Equal, -- := Eterm, Sterm + Tok_Colon, -- : Eterm, Sterm + Tok_Greater_Greater, -- >> Eterm, Sterm + + Tok_Abstract, -- ABSTRACT Eterm, Sterm + Tok_Access, -- ACCESS Eterm, Sterm + Tok_Aliased, -- ALIASED Eterm, Sterm + Tok_All, -- ALL Eterm, Sterm + Tok_Array, -- ARRAY Eterm, Sterm + Tok_At, -- AT Eterm, Sterm + Tok_Body, -- BODY Eterm, Sterm + Tok_Constant, -- CONSTANT Eterm, Sterm + Tok_Do, -- DO Eterm, Sterm + Tok_Is, -- IS Eterm, Sterm + Tok_Limited, -- LIMITED Eterm, Sterm + Tok_Of, -- OF Eterm, Sterm + Tok_Out, -- OUT Eterm, Sterm + Tok_Record, -- RECORD Eterm, Sterm + Tok_Renames, -- RENAMES Eterm, Sterm + Tok_Reverse, -- REVERSE Eterm, Sterm + Tok_Tagged, -- TAGGED Eterm, Sterm + Tok_Then, -- THEN Eterm, Sterm + + Tok_Less_Less, -- << Eterm, Sterm, After_SM + + Tok_Abort, -- ABORT Eterm, Sterm, After_SM + Tok_Accept, -- ACCEPT Eterm, Sterm, After_SM + Tok_Case, -- CASE Eterm, Sterm, After_SM + Tok_Delay, -- DELAY Eterm, Sterm, After_SM + Tok_Else, -- ELSE Eterm, Sterm, After_SM + Tok_Elsif, -- ELSIF Eterm, Sterm, After_SM + Tok_End, -- END Eterm, Sterm, After_SM + Tok_Exception, -- EXCEPTION Eterm, Sterm, After_SM + Tok_Exit, -- EXIT Eterm, Sterm, After_SM + Tok_Goto, -- GOTO Eterm, Sterm, After_SM + Tok_If, -- IF Eterm, Sterm, After_SM + Tok_Pragma, -- PRAGMA Eterm, Sterm, After_SM + Tok_Raise, -- RAISE Eterm, Sterm, After_SM + Tok_Requeue, -- REQUEUE Eterm, Sterm, After_SM + Tok_Return, -- RETURN Eterm, Sterm, After_SM + Tok_Select, -- SELECT Eterm, Sterm, After_SM + Tok_Terminate, -- TERMINATE Eterm, Sterm, After_SM + Tok_Until, -- UNTIL Eterm, Sterm, After_SM + Tok_When, -- WHEN Eterm, Sterm, After_SM + + Tok_Begin, -- BEGIN Eterm, Sterm, After_SM, Labeled_Stmt + Tok_Declare, -- DECLARE Eterm, Sterm, After_SM, Labeled_Stmt + Tok_For, -- FOR Eterm, Sterm, After_SM, Labeled_Stmt + Tok_Loop, -- LOOP Eterm, Sterm, After_SM, Labeled_Stmt + Tok_While, -- WHILE Eterm, Sterm, After_SM, Labeled_Stmt + + Tok_Entry, -- ENTRY Eterm, Sterm, Declk, Deckn, After_SM + Tok_Protected, -- PROTECTED Eterm, Sterm, Declk, Deckn, After_SM + Tok_Task, -- TASK Eterm, Sterm, Declk, Deckn, After_SM + Tok_Type, -- TYPE Eterm, Sterm, Declk, Deckn, After_SM + Tok_Subtype, -- SUBTYPE Eterm, Sterm, Declk, Deckn, After_SM + Tok_Use, -- USE Eterm, Sterm, Declk, Deckn, After_SM + + Tok_Function, -- FUNCTION Eterm, Sterm, Cunit, Declk, After_SM + Tok_Generic, -- GENERIC Eterm, Sterm, Cunit, Declk, After_SM + Tok_Package, -- PACKAGE Eterm, Sterm, Cunit, Declk, After_SM + Tok_Procedure, -- PROCEDURE Eterm, Sterm, Cunit, Declk, After_SM + + Tok_Private, -- PRIVATE Eterm, Sterm, Cunit, After_SM + Tok_With, -- WITH Eterm, Sterm, Cunit, After_SM + Tok_Separate, -- SEPARATE Eterm, Sterm, Cunit, After_SM + + Tok_EOF, -- End of file Eterm, Sterm, Cterm, After_SM + + Tok_Semicolon, -- ; Eterm, Sterm, Cterm + + Tok_Arrow, -- => Sterm, Cterm, Chtok + + Tok_Vertical_Bar, -- | Cterm, Sterm, Chtok + + Tok_Dot_Dot, -- .. Sterm, Chtok + + -- The following three entries are used only when scanning + -- project files. + + Tok_Project, + Tok_Modifying, + Tok_External, + + No_Token); + -- No_Token is used for initializing Token values to indicate that + -- no value has been set yet. + + -- Note: in the RM, operator symbol is a special case of string literal. + -- We distinguish at the lexical level in this compiler, since there are + -- many syntactic situations in which only an operator symbol is allowed. + + -- The following subtype declarations group the token types into classes. + -- These are used for class tests in the parser. + + subtype Token_Class_Numeric_Literal is + Token_Type range Tok_Integer_Literal .. Tok_Real_Literal; + -- Numeric literal + + subtype Token_Class_Literal is + Token_Type range Tok_Integer_Literal .. Tok_Operator_Symbol; + -- Literal + + subtype Token_Class_Lit_Or_Name is + Token_Type range Tok_Integer_Literal .. Tok_Identifier; + + subtype Token_Class_Binary_Addop is + Token_Type range Tok_Ampersand .. Tok_Plus; + -- Binary adding operator (& + -) + + subtype Token_Class_Unary_Addop is + Token_Type range Tok_Minus .. Tok_Plus; + -- Unary adding operator (+ -) + + subtype Token_Class_Mulop is + Token_Type range Tok_Asterisk .. Tok_Slash; + -- Multiplying operator + + subtype Token_Class_Logop is + Token_Type range Tok_And .. Tok_Xor; + -- Logical operator (and, or, xor) + + subtype Token_Class_Relop is + Token_Type range Tok_Less .. Tok_Box; + -- Relational operator (= /= < <= > >= not, in plus <> to catch misuse + -- of Pascal style not equal operator). + + subtype Token_Class_Name is + Token_Type range Tok_Char_Literal .. Tok_Identifier; + -- First token of name (4.1), + -- (identifier, char literal, operator symbol) + + subtype Token_Class_Desig is + Token_Type range Tok_Operator_Symbol .. Tok_Identifier; + -- Token which can be a Designator (identifier, operator symbol) + + subtype Token_Class_Namext is + Token_Type range Tok_Dot .. Tok_Left_Paren; + -- Name extension tokens. These are tokens which can appear immediately + -- after a name to extend it recursively (period, quote, left paren) + + subtype Token_Class_Consk is + Token_Type range Tok_Left_Paren .. Tok_Range; + -- Keywords which can start constraint + -- (left paren, delta, digits, range) + + subtype Token_Class_Eterm is + Token_Type range Tok_Colon_Equal .. Tok_Semicolon; + -- Expression terminators. These tokens can never appear within a simple + -- expression. This is used for error recovery purposes (if we encounter + -- an error in an expression, we simply scan to the next Eterm token). + + subtype Token_Class_Sterm is + Token_Type range Tok_Delta .. Tok_Dot_Dot; + -- Simple_Expression terminators. A Simple_Expression must be followed + -- by a token in this class, or an error message is issued complaining + -- about a missing binary operator. + + subtype Token_Class_Atkwd is + Token_Type range Tok_Delta .. Tok_Range; + -- Attribute keywords. This class includes keywords which can be used + -- as an Attribute_Designator, namely DELTA, DIGITS and RANGE + + subtype Token_Class_Cterm is + Token_Type range Tok_EOF .. Tok_Vertical_Bar; + -- Choice terminators. These tokens terminate a choice. This is used for + -- error recovery purposes (if we encounter an error in a Choice, we + -- simply scan to the next Cterm token). + + subtype Token_Class_Chtok is + Token_Type range Tok_Arrow .. Tok_Dot_Dot; + -- Choice tokens. These tokens signal a choice when used in an Aggregate + + subtype Token_Class_Cunit is + Token_Type range Tok_Function .. Tok_Separate; + -- Tokens which can begin a compilation unit + + subtype Token_Class_Declk is + Token_Type range Tok_Entry .. Tok_Procedure; + -- Keywords which start a declaration + + subtype Token_Class_Deckn is + Token_Type range Tok_Entry .. Tok_Use; + -- Keywords which start a declaration but can't start a compilation unit + + subtype Token_Class_After_SM is + Token_Type range Tok_Less_Less .. Tok_EOF; + -- Tokens which always, or almost always, appear after a semicolon. Used + -- in the Resync_Past_Semicolon routine to avoid gobbling up stuff when + -- a semicolon is missing. Of significance only for error recovery. + + subtype Token_Class_Labeled_Stmt is + Token_Type range Tok_Begin .. Tok_While; + -- Tokens which start labeled statements + + type Token_Flag_Array is array (Token_Type) of Boolean; + Is_Reserved_Keyword : constant Token_Flag_Array := Token_Flag_Array'( + Tok_Mod .. Tok_Rem => True, + Tok_New .. Tok_Null => True, + Tok_Delta .. Tok_Range => True, + Tok_And .. Tok_Xor => True, + Tok_In .. Tok_Not => True, + Tok_Abstract .. Tok_Then => True, + Tok_Abort .. Tok_Separate => True, + others => False); + -- Flag array used to test for reserved word + + -------------------------- + -- Scan State Variables -- + -------------------------- + + -- Note: these variables can only be referenced during the parsing of a + -- file. Reference to any of them from Sem or the expander is wrong. + + Scan_Ptr : Source_Ptr; + -- Current scan pointer location. After a call to Scan, this points + -- just past the end of the token just scanned. + + Token : Token_Type; + -- Type of current token + + Token_Ptr : Source_Ptr; + -- Pointer to first character of current token + + Current_Line_Start : Source_Ptr; + -- Pointer to first character of line containing current token + + Start_Column : Column_Number; + -- Starting column number (zero origin) of the first non-blank character + -- on the line containing the current token. This is used for error + -- recovery circuits which depend on looking at the column line up. + + Checksum : Word; + -- Used to accumulate a checksum representing the tokens in the source + -- file being compiled. This checksum includes only program tokens, and + -- excludes comments. + + First_Non_Blank_Location : Source_Ptr; + -- Location of first non-blank character on the line containing the + -- current token (i.e. the location of the character whose column number + -- is stored in Start_Column). + + Token_Node : Node_Id := Empty; + -- Node table Id for the current token. This is set only if the current + -- token is one for which the scanner constructs a node (i.e. it is an + -- identifier, operator symbol, or literal. For other token types, + -- Token_Node is undefined. + + Token_Name : Name_Id := No_Name; + -- For identifiers, this is set to the Name_Id of the identifier scanned. + -- For all other tokens, Token_Name is set to Error_Name. Note that it + -- would be possible for the caller to extract this information from + -- Token_Node. We set Token_Name separately for two reasons. First it + -- allows a quicker test for a specific identifier. Second, it allows + -- a version of the parser to be built that does not build tree nodes, + -- usable as a syntax checker. + + Prev_Token : Token_Type := No_Token; + -- Type of previous token + + Prev_Token_Ptr : Source_Ptr; + -- Pointer to first character of previous token + + Version_To_Be_Found : Boolean; + -- This flag is True if the scanner is still looking for an RCS version + -- number in a comment. Normally it is initialized to False so that this + -- circuit is not activated. If the -dv switch is set, then this flag is + -- initialized to True, and then reset when the version number is found. + -- We do things this way to minimize the impact on comment scanning. + + -------------------------------------------------------- + -- Procedures for Saving and Restoring the Scan State -- + -------------------------------------------------------- + + -- The following procedures can be used to save and restore the entire + -- scan state. They are used in cases where it is necessary to backup + -- the scan during the parse. + + type Saved_Scan_State is private; + -- Used for saving and restoring the scan state + + procedure Save_Scan_State (Saved_State : out Saved_Scan_State); + pragma Inline (Save_Scan_State); + -- Saves the current scan state for possible later restoration. Note that + -- there is no harm in saving the state and then never restoring it. + + procedure Restore_Scan_State (Saved_State : in Saved_Scan_State); + pragma Inline (Restore_Scan_State); + -- Restores a scan state saved by a call to Save_Scan_State. + -- The saved scan state must refer to the current source file. + +private + type Saved_Scan_State is record + Save_Scan_Ptr : Source_Ptr; + Save_Token : Token_Type; + Save_Token_Ptr : Source_Ptr; + Save_Current_Line_Start : Source_Ptr; + Save_Start_Column : Column_Number; + Save_Checksum : Word; + Save_First_Non_Blank_Location : Source_Ptr; + Save_Token_Node : Node_Id; + Save_Token_Name : Name_Id; + Save_Prev_Token : Token_Type; + Save_Prev_Token_Ptr : Source_Ptr; + end record; + +end Scans; |