(*
    BSD 2-Clause License

    Copyright (c) 2018-2019, Anton Krotov
    All rights reserved.
*)

MODULE RTL;

IMPORT SYSTEM, API;


CONST

    bit_depth* = 32;
    maxint* = 7FFFFFFFH;
    minint* = 80000000H;

    DLL_PROCESS_ATTACH = 1;
    DLL_THREAD_ATTACH  = 2;
    DLL_THREAD_DETACH  = 3;
    DLL_PROCESS_DETACH = 0;

    WORD = bit_depth DIV 8;
    MAX_SET = bit_depth - 1;


TYPE

    DLL_ENTRY* = PROCEDURE (hinstDLL, fdwReason, lpvReserved: INTEGER);
    PROC       = PROCEDURE;


VAR

    name:  INTEGER;
    types: INTEGER;
    bits:  ARRAY MAX_SET + 1 OF INTEGER;

    dll: RECORD
        process_detach,
        thread_detach,
        thread_attach: DLL_ENTRY
    END;

    fini: PROC;


PROCEDURE [stdcall] _move* (bytes, dest, source: INTEGER);
BEGIN
    SYSTEM.CODE(
    08BH, 045H, 008H,    (*  mov eax, dword [ebp + 8]   *)
    085H, 0C0H,          (*  test eax, eax              *)
    07EH, 019H,          (*  jle L                      *)
    0FCH,                (*  cld                        *)
    057H,                (*  push edi                   *)
    056H,                (*  push esi                   *)
    08BH, 075H, 010H,    (*  mov esi, dword [ebp + 16]  *)
    08BH, 07DH, 00CH,    (*  mov edi, dword [ebp + 12]  *)
    089H, 0C1H,          (*  mov ecx, eax               *)
    0C1H, 0E9H, 002H,    (*  shr ecx, 2                 *)
    0F3H, 0A5H,          (*  rep movsd                  *)
    089H, 0C1H,          (*  mov ecx, eax               *)
    083H, 0E1H, 003H,    (*  and ecx, 3                 *)
    0F3H, 0A4H,          (*  rep movsb                  *)
    05EH,                (*  pop esi                    *)
    05FH                 (*  pop edi                    *)
                         (*  L:                         *)
                )
END _move;


PROCEDURE [stdcall] _arrcpy* (base_size, len_dst, dst, len_src, src: INTEGER): BOOLEAN;
VAR
    res: BOOLEAN;

BEGIN
    IF len_src > len_dst THEN
        res := FALSE
    ELSE
        _move(len_src * base_size, dst, src);
        res := TRUE
    END

    RETURN res
END _arrcpy;


PROCEDURE [stdcall] _strcpy* (chr_size, len_src, src, len_dst, dst: INTEGER);
BEGIN
    _move(MIN(len_dst, len_src) * chr_size, dst, src)
END _strcpy;


PROCEDURE [stdcall] _rot* (VAR A: ARRAY OF INTEGER);
VAR
    i, n, k: INTEGER;

BEGIN

    k := LEN(A) - 1;
    n := A[0];
    i := 0;
    WHILE i < k DO
        A[i] := A[i + 1];
        INC(i)
    END;
    A[k] := n

END _rot;


PROCEDURE [stdcall] _set* (b, a: INTEGER): INTEGER;
BEGIN
    IF (a <= b) & (a <= MAX_SET) & (b >= 0) THEN
        IF b > MAX_SET THEN
            b := MAX_SET
        END;
        IF a < 0 THEN
            a := 0
        END;
        a := LSR(ASR(minint, b - a), MAX_SET - b)
    ELSE
        a := 0
    END

    RETURN a
END _set;


PROCEDURE [stdcall] _set1* (a: INTEGER): INTEGER;
BEGIN
    IF ASR(a, 5) = 0 THEN
        SYSTEM.GET(SYSTEM.ADR(bits[0]) + a * WORD, a)
    ELSE
        a := 0
    END
    RETURN a
END _set1;


PROCEDURE [stdcall] _divmod* (y, x: INTEGER); (* (x div y) -> eax; (x mod y) -> edx *)
BEGIN
    SYSTEM.CODE(
    053H,                (*  push    ebx                    *)
    08BH, 045H, 00CH,    (*  mov     eax, dword [ebp + 12]  *)  (* eax <- x *)
    031H, 0D2H,          (*  xor     edx, edx               *)
    085H, 0C0H,          (*  test    eax, eax               *)
    074H, 018H,          (*  je      L2                     *)
    07FH, 002H,          (*  jg      L1                     *)
    0F7H, 0D2H,          (*  not     edx                    *)
                         (*  L1:                            *)
    089H, 0C3H,          (*  mov     ebx, eax               *)
    08BH, 04DH, 008H,    (*  mov     ecx, dword [ebp + 8]   *)  (* ecx <- y *)
    0F7H, 0F9H,          (*  idiv    ecx                    *)
    085H, 0D2H,          (*  test    edx, edx               *)
    074H, 009H,          (*  je      L2                     *)
    031H, 0CBH,          (*  xor     ebx, ecx               *)
    085H, 0DBH,          (*  test    ebx, ebx               *)
    07DH, 003H,          (*  jge     L2                     *)
    048H,                (*  dec     eax                    *)
    001H, 0CAH,          (*  add     edx, ecx               *)
                         (*  L2:                            *)
    05BH                 (*  pop     ebx                    *)
               )
END _divmod;


PROCEDURE [stdcall] _new* (t, size: INTEGER; VAR ptr: INTEGER);
BEGIN
    ptr := API._NEW(size);
    IF ptr # 0 THEN
        SYSTEM.PUT(ptr, t);
        INC(ptr, WORD)
    END
END _new;


PROCEDURE [stdcall] _dispose* (VAR ptr: INTEGER);
BEGIN
    IF ptr # 0 THEN
        ptr := API._DISPOSE(ptr - WORD)
    END
END _dispose;


PROCEDURE [stdcall] _length* (len, str: INTEGER);
BEGIN
    SYSTEM.CODE(
    08BH, 045H, 00CH,    (*  mov     eax, dword [ebp + 0Ch]  *)
    08BH, 04DH, 008H,    (*  mov     ecx, dword [ebp + 08h]  *)
    048H,                (*  dec     eax                     *)
                         (*  L1:                             *)
    040H,                (*  inc     eax                     *)
    080H, 038H, 000H,    (*  cmp     byte [eax], 0           *)
    074H, 003H,          (*  jz      L2                      *)
    0E2H, 0F8H,          (*  loop    L1                      *)
    040H,                (*  inc     eax                     *)
                         (*  L2:                             *)
    02BH, 045H, 00CH     (*  sub     eax, dword [ebp + 0Ch]  *)
               )
END _length;


PROCEDURE [stdcall] _lengthw* (len, str: INTEGER);
BEGIN
    SYSTEM.CODE(
    08BH, 045H, 00CH,         (*  mov     eax, dword [ebp + 0Ch]  *)
    08BH, 04DH, 008H,         (*  mov     ecx, dword [ebp + 08h]  *)
    048H,                     (*  dec     eax                     *)
    048H,                     (*  dec     eax                     *)
                              (*  L1:                             *)
    040H,                     (*  inc     eax                     *)
    040H,                     (*  inc     eax                     *)
    066H, 083H, 038H, 000H,   (*  cmp     word [eax], 0           *)
    074H, 004H,               (*  jz      L2                      *)
    0E2H, 0F6H,               (*  loop    L1                      *)
    040H,                     (*  inc     eax                     *)
    040H,                     (*  inc     eax                     *)
                              (*  L2:                             *)
    02BH, 045H, 00CH,         (*  sub     eax, dword [ebp + 0Ch]  *)
    0D1H, 0E8H                (*  shr     eax, 1                  *)
               )
END _lengthw;


PROCEDURE [stdcall] strncmp (a, b, n: INTEGER): INTEGER;
BEGIN
    SYSTEM.CODE(
    056H,                    (*  push    esi                            *)
    057H,                    (*  push    edi                            *)
    053H,                    (*  push    ebx                            *)
    08BH, 075H, 008H,        (*  mov     esi, dword[ebp +  8]; esi <- a *)
    08BH, 07DH, 00CH,        (*  mov     edi, dword[ebp + 12]; edi <- b *)
    08BH, 05DH, 010H,        (*  mov     ebx, dword[ebp + 16]; ebx <- n *)
    031H, 0C9H,              (*  xor     ecx, ecx                       *)
    031H, 0D2H,              (*  xor     edx, edx                       *)
    0B8H,
    000H, 000H, 000H, 080H,  (*  mov     eax, minint                    *)
                             (*  L1:                                    *)
    085H, 0DBH,              (*  test    ebx, ebx                       *)
    07EH, 017H,              (*  jle     L3                             *)
    08AH, 00EH,              (*  mov     cl, byte[esi]                  *)
    08AH, 017H,              (*  mov     dl, byte[edi]                  *)
    046H,                    (*  inc     esi                            *)
    047H,                    (*  inc     edi                            *)
    04BH,                    (*  dec     ebx                            *)
    039H, 0D1H,              (*  cmp     ecx, edx                       *)
    074H, 006H,              (*  je      L2                             *)
    089H, 0C8H,              (*  mov     eax, ecx                       *)
    029H, 0D0H,              (*  sub     eax, edx                       *)
    0EBH, 006H,              (*  jmp     L3                             *)
                             (*  L2:                                    *)
    085H, 0C9H,              (*  test    ecx, ecx                       *)
    075H, 0E7H,              (*  jne     L1                             *)
    031H, 0C0H,              (*  xor     eax, eax                       *)
                             (*  L3:                                    *)
    05BH,                    (*  pop     ebx                            *)
    05FH,                    (*  pop     edi                            *)
    05EH,                    (*  pop     esi                            *)
    05DH,                    (*  pop     ebp                            *)
    0C2H, 00CH, 000H         (*  ret     12                             *)
    )
    RETURN 0
END strncmp;


PROCEDURE [stdcall] strncmpw (a, b, n: INTEGER): INTEGER;
BEGIN
    SYSTEM.CODE(
    056H,                    (*  push    esi                            *)
    057H,                    (*  push    edi                            *)
    053H,                    (*  push    ebx                            *)
    08BH, 075H, 008H,        (*  mov     esi, dword[ebp +  8]; esi <- a *)
    08BH, 07DH, 00CH,        (*  mov     edi, dword[ebp + 12]; edi <- b *)
    08BH, 05DH, 010H,        (*  mov     ebx, dword[ebp + 16]; ebx <- n *)
    031H, 0C9H,              (*  xor     ecx, ecx                       *)
    031H, 0D2H,              (*  xor     edx, edx                       *)
    0B8H,
    000H, 000H, 000H, 080H,  (*  mov     eax, minint                    *)
                             (*  L1:                                    *)
    085H, 0DBH,              (*  test    ebx, ebx                       *)
    07EH, 01BH,              (*  jle     L3                             *)
    066H, 08BH, 00EH,        (*  mov     cx, word[esi]                  *)
    066H, 08BH, 017H,        (*  mov     dx, word[edi]                  *)
    046H,                    (*  inc     esi                            *)
    046H,                    (*  inc     esi                            *)
    047H,                    (*  inc     edi                            *)
    047H,                    (*  inc     edi                            *)
    04BH,                    (*  dec     ebx                            *)
    039H, 0D1H,              (*  cmp     ecx, edx                       *)
    074H, 006H,              (*  je      L2                             *)
    089H, 0C8H,              (*  mov     eax, ecx                       *)
    029H, 0D0H,              (*  sub     eax, edx                       *)
    0EBH, 006H,              (*  jmp     L3                             *)
                             (*  L2:                                    *)
    085H, 0C9H,              (*  test    ecx, ecx                       *)
    075H, 0E3H,              (*  jne     L1                             *)
    031H, 0C0H,              (*  xor     eax, eax                       *)
                             (*  L3:                                    *)
    05BH,                    (*  pop     ebx                            *)
    05FH,                    (*  pop     edi                            *)
    05EH,                    (*  pop     esi                            *)
    05DH,                    (*  pop     ebp                            *)
    0C2H, 00CH, 000H         (*  ret     12                             *)
    )
    RETURN 0
END strncmpw;


PROCEDURE [stdcall] _strcmp* (op, len2, str2, len1, str1: INTEGER): BOOLEAN;
VAR
    res:  INTEGER;
    bRes: BOOLEAN;
    c:    CHAR;

BEGIN

    res := strncmp(str1, str2, MIN(len1, len2));
    IF res = minint THEN
        IF len1 > len2 THEN
            SYSTEM.GET(str1 + len2, c);
            res := ORD(c)
        ELSIF len1 < len2 THEN
            SYSTEM.GET(str2 + len1, c);
            res := -ORD(c)
        ELSE
            res := 0
        END
    END;

    CASE op OF
    |0: bRes := res =  0
    |1: bRes := res #  0
    |2: bRes := res <  0
    |3: bRes := res <= 0
    |4: bRes := res >  0
    |5: bRes := res >= 0
    END

    RETURN bRes
END _strcmp;


PROCEDURE [stdcall] _strcmpw* (op, len2, str2, len1, str1: INTEGER): BOOLEAN;
VAR
    res:  INTEGER;
    bRes: BOOLEAN;
    c:    WCHAR;

BEGIN

    res := strncmpw(str1, str2, MIN(len1, len2));
    IF res = minint THEN
        IF len1 > len2 THEN
            SYSTEM.GET(str1 + len2 * 2, c);
            res := ORD(c)
        ELSIF len1 < len2 THEN
            SYSTEM.GET(str2 + len1 * 2, c);
            res := -ORD(c)
        ELSE
            res := 0
        END
    END;

    CASE op OF
    |0: bRes := res =  0
    |1: bRes := res #  0
    |2: bRes := res <  0
    |3: bRes := res <= 0
    |4: bRes := res >  0
    |5: bRes := res >= 0
    END

    RETURN bRes
END _strcmpw;


PROCEDURE PCharToStr (pchar: INTEGER; VAR s: ARRAY OF CHAR);
VAR
    c: CHAR;
    i: INTEGER;

BEGIN
    i := 0;
    REPEAT
        SYSTEM.GET(pchar, c);
        s[i] := c;
        INC(pchar);
        INC(i)
    UNTIL c = 0X
END PCharToStr;


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

BEGIN

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

    a := 0;
    b := i - 1;
    WHILE a < b DO
        c := str[a];
        str[a] := str[b];
        str[b] := c;
        INC(a);
        DEC(b)
    END;
    str[i] := 0X
END IntToStr;


PROCEDURE append (VAR s1: ARRAY OF CHAR; s2: ARRAY OF CHAR);
VAR
    n1, n2, i, j: INTEGER;
BEGIN
    n1 := LENGTH(s1);
    n2 := LENGTH(s2);

    ASSERT(n1 + n2 < LEN(s1));

    i := 0;
    j := n1;
    WHILE i < n2 DO
        s1[j] := s2[i];
        INC(i);
        INC(j)
    END;

    s1[j] := 0X

END append;


PROCEDURE [stdcall] _error* (module, err, line: INTEGER);
VAR
    s, temp: ARRAY 1024 OF CHAR;

BEGIN

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

    append(s, API.eol);

    append(s, "module: "); PCharToStr(module, temp); append(s, temp); append(s, API.eol);
    append(s, "line: ");   IntToStr(line, temp);     append(s, temp);

    API.DebugMsg(SYSTEM.ADR(s[0]), name);

    API.exit_thread(0)
END _error;


PROCEDURE [stdcall] _isrec* (t0, t1, r: INTEGER): INTEGER;
BEGIN
    SYSTEM.GET(t0 + t1 + types, t0)
    RETURN t0 MOD 2
END _isrec;


PROCEDURE [stdcall] _is* (t0, p: INTEGER): INTEGER;
BEGIN
    IF p # 0 THEN
        SYSTEM.GET(p - WORD, p);
        SYSTEM.GET(t0 + p + types, p)
    END

    RETURN p MOD 2
END _is;


PROCEDURE [stdcall] _guardrec* (t0, t1: INTEGER): INTEGER;
BEGIN
    SYSTEM.GET(t0 + t1 + types, t0)
    RETURN t0 MOD 2
END _guardrec;


PROCEDURE [stdcall] _guard* (t0, p: INTEGER): INTEGER;
BEGIN
    SYSTEM.GET(p, p);
    IF p # 0 THEN
        SYSTEM.GET(p - WORD, p);
        SYSTEM.GET(t0 + p + types, p)
    ELSE
        p := 1
    END

    RETURN p MOD 2
END _guard;


PROCEDURE [stdcall] _dllentry* (hinstDLL, fdwReason, lpvReserved: INTEGER): INTEGER;
VAR
    res: INTEGER;

BEGIN
    CASE fdwReason OF
    |DLL_PROCESS_ATTACH:
        res := 1
    |DLL_THREAD_ATTACH:
        res := 0;
        IF dll.thread_attach # NIL THEN
            dll.thread_attach(hinstDLL, fdwReason, lpvReserved)
        END
    |DLL_THREAD_DETACH:
        res := 0;
        IF dll.thread_detach # NIL THEN
            dll.thread_detach(hinstDLL, fdwReason, lpvReserved)
        END
    |DLL_PROCESS_DETACH:
        res := 0;
        IF dll.process_detach # NIL THEN
            dll.process_detach(hinstDLL, fdwReason, lpvReserved)
        END
    ELSE
        res := 0
    END

    RETURN res
END _dllentry;


PROCEDURE [stdcall] _exit* (code: INTEGER);
BEGIN
    API.exit(code)
END _exit;


PROCEDURE [stdcall] _init* (modname: INTEGER; tcount, _types: INTEGER; code, param: INTEGER);
VAR
    t0, t1, i, j: INTEGER;

BEGIN
    SYSTEM.CODE(09BH, 0DBH, 0E3H); (* finit *)
    API.init(param, code);

    types := API._NEW(tcount * tcount + SYSTEM.SIZE(INTEGER));
    ASSERT(types # 0);
    FOR i := 0 TO tcount - 1 DO
        FOR j := 0 TO tcount - 1 DO
            t0 := i; t1 := j;

            WHILE (t1 # 0) & (t1 # t0) DO
                SYSTEM.GET(_types + t1 * WORD, t1)
            END;

            SYSTEM.PUT8(i * tcount + j + types, ORD(t0 = t1))
        END
    END;

    j := 1;
    FOR i := 0 TO MAX_SET DO
        bits[i] := j;
        j := LSL(j, 1)
    END;

    name := modname;

    dll.process_detach := NIL;
    dll.thread_detach  := NIL;
    dll.thread_attach  := NIL;

    fini := NIL
END _init;


PROCEDURE [stdcall] _sofinit*;
BEGIN
    IF fini # NIL THEN
        fini
    END
END _sofinit;


PROCEDURE SetDll* (process_detach, thread_detach, thread_attach: DLL_ENTRY);
BEGIN
    dll.process_detach := process_detach;
    dll.thread_detach  := thread_detach;
    dll.thread_attach  := thread_attach
END SetDll;


PROCEDURE SetFini* (ProcFini: PROC);
BEGIN
    fini := ProcFini
END SetFini;


END RTL.