+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S C A N S --
--- --
--- S p e c --
--- --
--- $Revision: 1.4.10.1 $
--- --
--- Copyright (C) 1992-2001 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. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-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, -- identifier 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_Extends,
- 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 CRC representing the tokens in the source
- -- file being compiled. This CRC 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;
projects / msp430-gcc.git / blobdiff