+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S C N . N L I T --
--- --
--- B o d y --
--- --
--- $Revision: 1.2.12.2 $
--- --
--- 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. --
--- --
--- GNAT was originally developed by the GNAT team at New York University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-with Uintp; use Uintp;
-with Urealp; use Urealp;
-
-separate (Scn)
-procedure Nlit is
-
- C : Character;
- -- Current source program character
-
- Base_Char : Character;
- -- Either # or : (character at start of based number)
-
- Base : Int;
- -- Value of base
-
- UI_Base : Uint;
- -- Value of base in Uint format
-
- UI_Int_Value : Uint;
- -- Value of integer scanned by Scan_Integer in Uint format
-
- UI_Num_Value : Uint;
- -- Value of integer in numeric value being scanned
-
- Scale : Int;
- -- Scale value for real literal
-
- UI_Scale : Uint;
- -- Scale in Uint format
-
- Exponent_Is_Negative : Boolean;
- -- Set true for negative exponent
-
- Extended_Digit_Value : Int;
- -- Extended digit value
-
- Point_Scanned : Boolean;
- -- Flag for decimal point scanned in numeric literal
-
- -----------------------
- -- Local Subprograms --
- -----------------------
-
- procedure Error_Digit_Expected;
- -- Signal error of bad digit, Scan_Ptr points to the location at which
- -- the digit was expected on input, and is unchanged on return.
-
- procedure Scan_Integer;
- -- Procedure to scan integer literal. On entry, Scan_Ptr points to a
- -- digit, on exit Scan_Ptr points past the last character of the integer.
- -- For each digit encountered, UI_Int_Value is multiplied by 10, and the
- -- value of the digit added to the result. In addition, the value in
- -- Scale is decremented by one for each actual digit scanned.
-
- --------------------------
- -- Error_Digit_Expected --
- --------------------------
-
- procedure Error_Digit_Expected is
- begin
- Error_Msg_S ("digit expected");
- end Error_Digit_Expected;
-
- -------------------
- -- Scan_Integer --
- -------------------
-
- procedure Scan_Integer is
- C : Character;
- -- Next character scanned
-
- begin
- C := Source (Scan_Ptr);
-
- -- Loop through digits (allowing underlines)
-
- loop
- Accumulate_Checksum (C);
- UI_Int_Value :=
- UI_Int_Value * 10 + (Character'Pos (C) - Character'Pos ('0'));
- Scan_Ptr := Scan_Ptr + 1;
- Scale := Scale - 1;
- C := Source (Scan_Ptr);
-
- if C = '_' then
- Accumulate_Checksum ('_');
-
- loop
- Scan_Ptr := Scan_Ptr + 1;
- C := Source (Scan_Ptr);
- exit when C /= '_';
- Error_No_Double_Underline;
- end loop;
-
- if C not in '0' .. '9' then
- Error_Digit_Expected;
- exit;
- end if;
-
- else
- exit when C not in '0' .. '9';
- end if;
- end loop;
-
- end Scan_Integer;
-
-----------------------------------
--- Start of Processing for Nlit --
-----------------------------------
-
-begin
- Base := 10;
- UI_Base := Uint_10;
- UI_Int_Value := Uint_0;
- Scale := 0;
- Scan_Integer;
- Scale := 0;
- Point_Scanned := False;
- UI_Num_Value := UI_Int_Value;
-
- -- Various possibilities now for continuing the literal are
- -- period, E/e (for exponent), or :/# (for based literal).
-
- Scale := 0;
- C := Source (Scan_Ptr);
-
- if C = '.' then
-
- -- Scan out point, but do not scan past .. which is a range sequence,
- -- and must not be eaten up scanning a numeric literal.
-
- while C = '.' and then Source (Scan_Ptr + 1) /= '.' loop
- Accumulate_Checksum ('.');
-
- if Point_Scanned then
- Error_Msg_S ("duplicate point ignored");
- end if;
-
- Point_Scanned := True;
- Scan_Ptr := Scan_Ptr + 1;
- C := Source (Scan_Ptr);
-
- if C not in '0' .. '9' then
- Error_Msg ("real literal cannot end with point", Scan_Ptr - 1);
- else
- Scan_Integer;
- UI_Num_Value := UI_Int_Value;
- end if;
- end loop;
-
- -- Based literal case. The base is the value we already scanned.
- -- In the case of colon, we insist that the following character
- -- is indeed an extended digit or a period. This catches a number
- -- of common errors, as well as catching the well known tricky
- -- bug otherwise arising from "x : integer range 1 .. 10:= 6;"
-
- elsif C = '#'
- or else (C = ':' and then
- (Source (Scan_Ptr + 1) = '.'
- or else
- Source (Scan_Ptr + 1) in '0' .. '9'
- or else
- Source (Scan_Ptr + 1) in 'A' .. 'Z'
- or else
- Source (Scan_Ptr + 1) in 'a' .. 'z'))
- then
- Accumulate_Checksum (C);
- Base_Char := C;
- UI_Base := UI_Int_Value;
-
- if UI_Base < 2 or else UI_Base > 16 then
- Error_Msg_SC ("base not 2-16");
- UI_Base := Uint_16;
- end if;
-
- Base := UI_To_Int (UI_Base);
- Scan_Ptr := Scan_Ptr + 1;
-
- -- Scan out extended integer [. integer]
-
- C := Source (Scan_Ptr);
- UI_Int_Value := Uint_0;
- Scale := 0;
-
- loop
- if C in '0' .. '9' then
- Accumulate_Checksum (C);
- Extended_Digit_Value :=
- Int'(Character'Pos (C)) - Int'(Character'Pos ('0'));
-
- elsif C in 'A' .. 'F' then
- Accumulate_Checksum (Character'Val (Character'Pos (C) + 32));
- Extended_Digit_Value :=
- Int'(Character'Pos (C)) - Int'(Character'Pos ('A')) + 10;
-
- elsif C in 'a' .. 'f' then
- Accumulate_Checksum (C);
- Extended_Digit_Value :=
- Int'(Character'Pos (C)) - Int'(Character'Pos ('a')) + 10;
-
- else
- Error_Msg_S ("extended digit expected");
- exit;
- end if;
-
- if Extended_Digit_Value >= Base then
- Error_Msg_S ("digit >= base");
- end if;
-
- UI_Int_Value := UI_Int_Value * UI_Base + Extended_Digit_Value;
- Scale := Scale - 1;
- Scan_Ptr := Scan_Ptr + 1;
- C := Source (Scan_Ptr);
-
- if C = '_' then
- loop
- Accumulate_Checksum ('_');
- Scan_Ptr := Scan_Ptr + 1;
- C := Source (Scan_Ptr);
- exit when C /= '_';
- Error_No_Double_Underline;
- end loop;
-
- elsif C = '.' then
- Accumulate_Checksum ('.');
-
- if Point_Scanned then
- Error_Msg_S ("duplicate point ignored");
- end if;
-
- Scan_Ptr := Scan_Ptr + 1;
- C := Source (Scan_Ptr);
- Point_Scanned := True;
- Scale := 0;
-
- elsif C = Base_Char then
- Accumulate_Checksum (C);
- Scan_Ptr := Scan_Ptr + 1;
- exit;
-
- elsif C = '#' or else C = ':' then
- Error_Msg_S ("based number delimiters must match");
- Scan_Ptr := Scan_Ptr + 1;
- exit;
-
- elsif not Identifier_Char (C) then
- if Base_Char = '#' then
- Error_Msg_S ("missing '#");
- else
- Error_Msg_S ("missing ':");
- end if;
-
- exit;
- end if;
-
- end loop;
-
- UI_Num_Value := UI_Int_Value;
- end if;
-
- -- Scan out exponent
-
- if not Point_Scanned then
- Scale := 0;
- UI_Scale := Uint_0;
- else
- UI_Scale := UI_From_Int (Scale);
- end if;
-
- if Source (Scan_Ptr) = 'e' or else Source (Scan_Ptr) = 'E' then
- Accumulate_Checksum ('e');
- Scan_Ptr := Scan_Ptr + 1;
- Exponent_Is_Negative := False;
-
- if Source (Scan_Ptr) = '+' then
- Accumulate_Checksum ('+');
- Scan_Ptr := Scan_Ptr + 1;
-
- elsif Source (Scan_Ptr) = '-' then
- Accumulate_Checksum ('-');
-
- if not Point_Scanned then
- Error_Msg_S ("negative exponent not allowed for integer literal");
- else
- Exponent_Is_Negative := True;
- end if;
-
- Scan_Ptr := Scan_Ptr + 1;
- end if;
-
- UI_Int_Value := Uint_0;
-
- if Source (Scan_Ptr) in '0' .. '9' then
- Scan_Integer;
- else
- Error_Digit_Expected;
- end if;
-
- if Exponent_Is_Negative then
- UI_Scale := UI_Scale - UI_Int_Value;
- else
- UI_Scale := UI_Scale + UI_Int_Value;
- end if;
- end if;
-
- -- Case of real literal to be returned
-
- if Point_Scanned then
- Token := Tok_Real_Literal;
- Token_Node := New_Node (N_Real_Literal, Token_Ptr);
- Set_Realval (Token_Node,
- UR_From_Components (
- Num => UI_Num_Value,
- Den => -UI_Scale,
- Rbase => Base));
-
- -- Case of integer literal to be returned
-
- else
- Token := Tok_Integer_Literal;
- Token_Node := New_Node (N_Integer_Literal, Token_Ptr);
-
- if UI_Scale = 0 then
- Set_Intval (Token_Node, UI_Num_Value);
-
- -- Avoid doing possibly expensive calculations in cases like
- -- parsing 163E800_000# when semantics will not be done anyway.
- -- This is especially useful when parsing garbled input.
-
- elsif Operating_Mode /= Check_Syntax
- and then (Errors_Detected = 0 or else Try_Semantics)
- then
- Set_Intval (Token_Node, UI_Num_Value * UI_Base ** UI_Scale);
-
- else
- Set_Intval (Token_Node, No_Uint);
- end if;
-
- end if;
-
- return;
-
-end Nlit;
projects / msp430-gcc.git / blobdiff