(*
    BSD 2-Clause License

    Copyright (c) 2020-2021, Anton Krotov
    All rights reserved.
*)

MODULE Trap;

IMPORT SYSTEM;


CONST

    SP = 4;


PROCEDURE [code] sp* (): INTEGER
    22, 0, SP;  (*  MOV R0, SP  *)


PROCEDURE [code] syscall* (ptr: INTEGER)
    22, 0, SP,  (*  MOV      R0, SP  *)
    27, 0, 8,   (*  ADD      R0,  8  *)
    16, 0, 0,   (*  LDD      R0, R0  *)
    67, 0, 0;   (*  SYSCALL  R0      *)


PROCEDURE Char (c: CHAR);
VAR
    a: ARRAY 2 OF INTEGER;

BEGIN
    a[0] := 8;
    a[1] := ORD(c);
    syscall(SYSTEM.ADR(a[0]))
END Char;


PROCEDURE String (s: ARRAY OF CHAR);
VAR
    i: INTEGER;

BEGIN
    i := 0;
    WHILE s[i] # 0X DO
        Char(s[i]);
        INC(i)
    END
END String;


PROCEDURE PString (ptr: INTEGER);
VAR
    c: CHAR;

BEGIN
    SYSTEM.GET(ptr, c);
    WHILE c # 0X DO
        Char(c);
        INC(ptr);
        SYSTEM.GET(ptr, c)
    END
END PString;


PROCEDURE Ln;
BEGIN
    String(0DX + 0AX)
END Ln;


PROCEDURE IntToStr (x: INTEGER; VAR str: ARRAY OF CHAR);
VAR
    i, a: INTEGER;

BEGIN
    i := 0;
    a := x;
    REPEAT
        INC(i);
        a := a DIV 10
    UNTIL a = 0;

    str[i] := 0X;

    REPEAT
        DEC(i);
        str[i] := CHR(x MOD 10 + ORD("0"));
        x := x DIV 10
    UNTIL x = 0
END IntToStr;


PROCEDURE Int (x: INTEGER);
VAR
    s: ARRAY 32 OF CHAR;

BEGIN
    IntToStr(x, s);
    String(s)
END Int;


PROCEDURE trap* (modnum, _module, err, line: INTEGER);
VAR
    s: ARRAY 32 OF CHAR;

BEGIN
    CASE err OF
    | 1: s := "assertion failure"
    | 2: s := "NIL dereference"
    | 3: s := "bad divisor"
    | 4: s := "NIL procedure call"
    | 5: s := "type guard error"
    | 6: s := "index out of range"
    | 7: s := "invalid CASE"
    | 8: s := "array assignment error"
    | 9: s := "CHR out of range"
    |10: s := "WCHR out of range"
    |11: s := "BYTE out of range"
    END;

    Ln;
    String("error ("); Int(err); String("): "); String(s); Ln;
    String("module: "); PString(_module); Ln;
    String("line: "); Int(line); Ln;

    SYSTEM.CODE(0, 0, 0)  (*  STOP  *)
END trap;


END Trap.