blackbox-linux-console/BlackBox/Dev0/Mod/CPM.txt

MODULE Dev0CPM;

	(* THIS IS TEXT COPY OF CPM.odc *)
	(* DO NOT EDIT *)

(**
	project	= "BlackBox"
	organization	= "www.oberon.ch"
	contributors	= "Oberon microsystems"
	version	= "System/Rsrc/About"
	copyright	= "System/Rsrc/About"
	license	= "Docu/BB-License"
	references	= "ftp://ftp.inf.ethz.ch/pub/software/Oberon/OberonV4/Docu/OP2.Paper.ps"
	changes	= ""
	issues	= ""

**)

	IMPORT SYSTEM, Kernel, Files (* , Stores, Models, Views, TextModels, TextMappers, StdLog, DevMarkers *);

	CONST
		ProcSize* = 4;	(* PROCEDURE type *)
		PointerSize* = 4;	(* POINTER type *)
		DArrSizeA* = 8;	(* dyn array descriptor *)
		DArrSizeB* = 4;	(* size = A + B * typ.n *)

		MaxSet* = 31;
		MaxIndex* = 7FFFFFFFH;	(* maximal index value for array declaration *)

		MinReal32Pat = 0FF7FFFFFH;	(* most positive, 32-bit pattern *)
		MinReal64PatL = 0FFFFFFFFH;	(* most  negative, lower 32-bit pattern *)
		MinReal64PatH = 0FFEFFFFFH;	(* most  negative, higher 32-bit pattern *)
		MaxReal32Pat = 07F7FFFFFH;	(* most positive, 32-bit pattern *)
		MaxReal64PatL = 0FFFFFFFFH;	(* most positive, lower 32-bit pattern *)
		MaxReal64PatH = 07FEFFFFFH;	(* most positive, higher 32-bit pattern *)
		InfRealPat = 07F800000H;	(* real infinity pattern *)


		(* inclusive range of parameter of standard procedure HALT *)
		MinHaltNr* = 0;
		MaxHaltNr* = 128;

		(* inclusive range of register number of procedures SYSTEM.GETREG and SYSTEM.PUTREG *)
		MinRegNr* = 0;
		MaxRegNr* = 31;

		(* maximal value of flag used to mark interface structures *)
		MaxSysFlag* = 127;	(* shortint *)
		CProcFlag* = 1;	(* code procedures *)

		(* maximal condition value of parameter of SYSTEM.CC *)
		MaxCC* = 15;

		(* initialization of constant address, must be different from any valid constant address *)
		ConstNotAlloc* = -1;

		(* whether hidden pointer fields have to be nevertheless exported *)
		ExpHdPtrFld* = TRUE;
		HdPtrName* = "@ptr";

		(* whether hidden untagged pointer fields have to be nevertheless exported *)
		ExpHdUtPtrFld* = TRUE;
		HdUtPtrName* = "@utptr";

		(* whether hidden procedure fields have to be nevertheless exported (may be used for System.Free) *)
		ExpHdProcFld* = TRUE;
		HdProcName* = "@proc";

		(* whether hidden bound procedures have to be nevertheless exported *)
		ExpHdTProc* = FALSE;
		HdTProcName* = "@tproc";

		(* maximal number of exported stuctures: *)
		MaxStruct* = 16000;	(* must be < MAX(INTEGER) DIV 2 in object model *)
		
		(* maximal number of record extensions: *)
		MaxExts* = 15;	(* defined by type descriptor layout *)
		
		(* whether field leaf of pointer variable p has to be set to FALSE, when NEW(p) or SYSTEM.NEW(p, n) is used *)
		NEWusingAdr* = FALSE;

		(* special character (< " ") returned by procedure Get, if end of text reached *)
		Eot* = 0X;
		
		(* warnings *)
		longreal* = 0; largeint* = 1; realConst* = 2; copy* = 3; lchr* = 4; lentier* = 5; invar* = 6; outvar* = 7;
		
		(* language options *)
		interface* = 1;
		com* = 2; comAware* = 3;
		som* = 4; somAware* = 5;
		oberon* = 6;
		java* = 7; javaAware* = 8;
		noCode* = 9;
		allSysVal* = 14;
		sysImp* = 15;
		trap* = 31;
		sys386 = 10; sys68k = 20;	(* processor type in options if system imported *)
		
	CONST
		SFdir = "Sym";
		OFdir = "Code";
		SYSdir = "System";
		SFtag = 6F4F5346H;	(* symbol file tag *)
		OFtag = 6F4F4346H;	(* object file tag *)
		maxErrors = 64;
		
TYPE
	File = POINTER TO RECORD next: File; f: Files.File END;

	VAR
		LEHost*: BOOLEAN;	(* little or big endian host *)
		MinReal32*, MaxReal32*, InfReal*,
		MinReal64*, MaxReal64*: REAL;
		noerr*: BOOLEAN;	(* no error found until now *)
		curpos*, startpos*, errpos*: INTEGER;	(* character, start, and error position in source file *)
		searchpos*: INTEGER;	(* search position in source file *)
		errors*: INTEGER;
		breakpc*: INTEGER;	(* set by OPV.Init *)
		options*: SET;	(* language options *)
		file*: Files.File;	(* used for sym file import *)
		codeDir*: ARRAY 16 OF CHAR;
		symDir*: ARRAY 16 OF CHAR;
		checksum*: INTEGER;	(* symbol file checksum *)

		errorMes*: ARRAY 4096 OF CHAR;

		lastpos: INTEGER;
		realpat: INTEGER;
		lrealpat: RECORD H, L: INTEGER END;
		fpi, fpj: SHORTINT; fp: ARRAY 4 OF SHORTCHAR;
		ObjFName: Files.Name;

		in: Files.Reader;
		oldSymFile, symFile, objFile: Files.File;
		inSym: Files.Reader;
		outSym, outObj: Files.Writer;
		
		errNo-, errPos-: ARRAY maxErrors OF INTEGER;
		
		lineReader: Files.Reader;
		lineNum: INTEGER;
		
		crc32tab: ARRAY 256 OF INTEGER;


	PROCEDURE^ err* (n: INTEGER);

	PROCEDURE Init* (source: Files.Reader);
	BEGIN
		in := source;
		noerr := TRUE; options := {};
		curpos := in.Pos(); errpos := curpos; lastpos := curpos - 11; errors := 0;
		codeDir := OFdir; symDir := SFdir;
		errorMes := ""
	END Init;
	
	PROCEDURE Close*;
	BEGIN
		oldSymFile := NIL; inSym := NIL;
		symFile := NIL; outSym := NIL;
		objFile := NIL; outObj := NIL;
		in := NIL; lineReader := NIL
	END Close;

	PROCEDURE Get* (VAR ch: SHORTCHAR);
		VAR
			ch1: BYTE;
	BEGIN
		REPEAT
			in.ReadByte(ch1);
			ch := SYSTEM.VAL(SHORTCHAR, ch1);
			INC(curpos)
		UNTIL (ch < 100X)
	END Get;
	
	PROCEDURE GetL* (VAR ch: CHAR);
		VAR
			sCh: SHORTCHAR;
	BEGIN
		Get(sCh);
		ch := sCh
	END GetL;
	
(*
	PROCEDURE LineOf* (pos: INTEGER): INTEGER;
		VAR ch: CHAR;
	BEGIN
		IF lineReader = NIL THEN lineReader := in.Base().NewReader(NIL); lineReader.SetPos(0); lineNum := 0 END;
		IF lineReader.Pos() > pos THEN lineReader.SetPos(0); lineNum := 0 END;
		WHILE lineReader.Pos() < pos DO
			lineReader.ReadChar(ch);
			IF ch = 0DX THEN INC(lineNum) END
		END;
		RETURN lineNum
	END LineOf;
*)

	PROCEDURE LoWord (r: REAL): INTEGER;
		VAR x: INTEGER;
	BEGIN
		x := SYSTEM.ADR(r);
		IF ~LEHost THEN INC(x, 4) END;
		SYSTEM.GET(x, x);
		RETURN x
	END LoWord;

	PROCEDURE HiWord (r: REAL): INTEGER;
		VAR x: INTEGER;
	BEGIN
		x := SYSTEM.ADR(r);
		IF LEHost THEN INC(x, 4) END;
		SYSTEM.GET(x, x);
		RETURN x
	END HiWord;
	
	PROCEDURE Compound (lo, hi: INTEGER): REAL;
		VAR r: REAL;
	BEGIN
		IF LEHost THEN
			SYSTEM.PUT(SYSTEM.ADR(r), lo); SYSTEM.PUT(SYSTEM.ADR(r) + 4, hi)
		ELSE
			SYSTEM.PUT(SYSTEM.ADR(r) + 4, lo); SYSTEM.PUT(SYSTEM.ADR(r), hi)
		END;
		RETURN r
	END Compound;


	(* sysflag control *)
	
	PROCEDURE ValidGuid* (VAR str: ARRAY OF SHORTCHAR): BOOLEAN;
		VAR i: SHORTINT; ch: SHORTCHAR;
	BEGIN
		IF (LEN(str$) # 38) OR (str[0] # "{") & (str[37] # "}") THEN RETURN FALSE END;
		i := 1;
		WHILE i < 37 DO
			ch := str[i];
			IF (i = 9) OR (i = 14) OR (i = 19) OR (i = 24) THEN
				IF ch # "-" THEN RETURN FALSE END
			ELSE
				IF (ch < "0") OR (ch > "9") & (CAP(ch) < "A") OR (CAP(ch) > "Z") THEN RETURN FALSE END
			END;
			INC(i)
		END;
		RETURN TRUE
	END ValidGuid;
	
	PROCEDURE GetProcSysFlag* (id: ARRAY OF SHORTCHAR; num: SHORTINT; VAR flag: SHORTINT);
	BEGIN
		IF id # "" THEN
			IF id = "code" THEN num := 1
			ELSIF id = "callback" THEN num := 2
			ELSIF id = "nostkchk" THEN num := 4
			ELSIF id = "ccall" THEN num := -10
			ELSIF id = "guarded" THEN num := 8
			ELSIF id = "noframe" THEN num := 16
			ELSIF id = "native" THEN num := -33
			ELSIF id = "bytecode" THEN num := -35
			END
		END;
		IF (options * {sysImp, sys386, sys68k} # {}) & ((num = 1) OR (num = 2)) THEN INC(flag, num)
		ELSIF (sys68k IN options) & (num = 4) THEN INC(flag, num)
		ELSIF (options * {sys386, interface} # {}) & (num = -10) & (flag = 0) THEN flag := -10
		ELSIF (options * {sys386, com} # {}) & (num = 8) & (flag = 0) THEN flag := 8
		ELSIF (options * {sysImp, sys386} # {}) & (num = 16) & (flag = 0) THEN flag := 16
		ELSIF ({sysImp, java} - options = {}) & ((num= -33) OR (num = -35)) & (flag = 0) THEN flag := num
		ELSE err(225); flag := 0
		END
	END GetProcSysFlag;
	
	PROCEDURE GetVarParSysFlag* (id: ARRAY OF SHORTCHAR; num: SHORTINT; VAR flag: SHORTINT);
		VAR old: SHORTINT;
	BEGIN
		old := flag; flag := 0;
		IF (options * {sys386, sys68k, interface, com} # {}) THEN
			IF (num = 1) OR (id = "nil") THEN
				IF ~ODD(old) THEN flag := SHORT(old + 1) END
			ELSIF ((num = 2) OR (id = "in")) & (oberon IN options) THEN
				IF old <= 1 THEN flag := SHORT(old + 2) END
			ELSIF ((num = 4) OR (id = "out")) & (oberon IN options) THEN
				IF old <= 1 THEN flag := SHORT(old + 4) END
			ELSIF ((num = 8) OR (id = "new")) & (options * {com, interface} # {}) THEN
				IF old <= 1 THEN flag := SHORT(old + 8) END
			ELSIF ((num = 16) OR (id = "iid")) & (com IN options) THEN
				IF old <= 1 THEN flag := SHORT(old + 16) END
			END
		END;
		IF flag = 0 THEN err(225) END
	END GetVarParSysFlag;
	
	PROCEDURE GetRecordSysFlag* (id: ARRAY OF SHORTCHAR; num: SHORTINT; VAR flag: SHORTINT);
		VAR old: SHORTINT;
	BEGIN
		old := flag; flag := 0;
		IF (num = 1) OR (id = "untagged") THEN
			IF (options * {sysImp, sys386, sys68k, interface, com, som} # {}) & (old = 0) THEN flag := 1 END
		ELSIF (num = 3) OR (id = "noalign") THEN
			IF (options * {sys386, sys68k, interface, com, som} # {}) & (old = 0) THEN flag := 3 END
		ELSIF (num = 4) OR (id = "align2") THEN
			IF (options * {sys386, interface, com} # {}) & (old = 0) THEN flag := 4 END
		ELSIF (num = 5) OR (id = "align4") THEN
			IF (options * {sys386, interface, com} # {}) & (old = 0) THEN flag := 5 END
		ELSIF (num = 6) OR (id = "align8") THEN
			IF (options * {sys386, interface, com} # {}) & (old = 0) THEN flag := 6 END
		ELSIF (num = 7) OR (id = "union") THEN
			IF (options * {sys386, sys68k, interface, com} # {}) & (old = 0) THEN flag := 7 END
		ELSIF (num = 10) OR (id = "interface") OR ValidGuid(id) THEN
			IF (com IN options) & (old = 0) THEN flag := 10 END
		ELSIF (num = -11) OR (id = "jint") THEN
			IF (java IN options) & (old = 0) THEN flag := -11 END
		ELSIF (num = -13) OR (id = "jstr") THEN
			IF (java IN options) & (old = 0) THEN flag := -13 END
		ELSIF (num = 20) OR (id = "som") THEN
			IF (som IN options) & (old = 0) THEN flag := 20 END
		END;
		IF flag = 0 THEN err(225) END
	END GetRecordSysFlag;
	
	PROCEDURE GetArraySysFlag* (id: ARRAY OF SHORTCHAR; num: SHORTINT; VAR flag: SHORTINT);
		VAR old: SHORTINT;
	BEGIN
		old := flag; flag := 0;
		IF (num = 1) OR (id = "untagged") THEN
			IF (options * {sysImp, sys386, sys68k, interface, com, som} # {}) & (old = 0) THEN flag := 1 END
		ELSIF (num = -12) OR (id = "jarr") THEN
			IF (java IN options) & (old = 0) THEN flag := -12 END
		ELSIF (num = -13) OR (id = "jstr") THEN
			IF (java IN options) & (old = 0) THEN flag := -13 END
		END;
		IF flag = 0 THEN err(225) END
	END GetArraySysFlag;
	
	PROCEDURE GetPointerSysFlag* (id: ARRAY OF SHORTCHAR; num: SHORTINT; VAR flag: SHORTINT);
		VAR old: SHORTINT;
	BEGIN
		old := flag; flag := 0;
		IF (num = 1) OR (id = "untagged") THEN
			IF (options * {sys386, sys68k, interface, com, som} # {}) & (old = 0) THEN flag := 1 END
		ELSIF (num = 2) OR (id = "handle") THEN
			IF (sys68k IN options) & (old = 0) THEN flag := 2 END
		ELSIF (num = 10) OR (id = "interface") THEN
			IF (com IN options) & (old = 0) THEN flag := 10 END
		ELSIF (num = 20) OR (id = "som") THEN
			IF (som IN options) & (old = 0) THEN flag := 20 END
		END;
		IF flag = 0 THEN err(225) END
	END GetPointerSysFlag;
	
	PROCEDURE GetProcTypSysFlag* (id: ARRAY OF SHORTCHAR; num: SHORTINT; VAR flag: SHORTINT);
	BEGIN
		IF ((num = -10) OR (id = "ccall")) & (options * {sys386, interface} # {}) THEN flag := -10
		ELSE err(225); flag := 0
		END
	END GetProcTypSysFlag;
	
	PROCEDURE PropagateRecordSysFlag* (baseFlag: SHORTINT; VAR flag: SHORTINT);
	BEGIN
		IF (baseFlag = 1) OR (baseFlag >= 3) & (baseFlag <= 7) THEN	(* propagate untagged .. union *)
			IF flag = 0 THEN flag := baseFlag
			ELSIF (flag = 6) & (baseFlag < 6) THEN (* OK *)	(* special case for 8 byte aligned records *)
			ELSIF flag # baseFlag THEN err(225); flag := 0
			END
		ELSIF (baseFlag # 10) & (flag = 10) THEN err(225)
		END
	END PropagateRecordSysFlag;
	
	PROCEDURE PropagateRecPtrSysFlag* (baseFlag: SHORTINT; VAR flag: SHORTINT);
	BEGIN
		IF (baseFlag = 1) OR (baseFlag >= 3) & (baseFlag <= 7) THEN	(* pointer to untagged .. union is untagged *)
			IF flag = 0 THEN flag := 1
			ELSIF (flag # 1) & (flag # 2) THEN err(225); flag := 0
			END
		ELSIF baseFlag = 10 THEN	(* pointer to interface is interface *)
			IF flag = 0 THEN flag := 10
			ELSIF flag # 10 THEN err(225); flag := 0
			END
		ELSIF baseFlag = -11 THEN	(* pointer to java interface is java interface *)
			IF flag # 0 THEN err(225) END;
			flag := -11
		ELSIF baseFlag = -13 THEN	(* pointer to java string is java string *)
			IF flag # 0 THEN err(225) END;
			flag := -13
		END
	END PropagateRecPtrSysFlag;
	
	PROCEDURE PropagateArrPtrSysFlag* (baseFlag: SHORTINT; VAR flag: SHORTINT);
	BEGIN
		IF baseFlag = 1 THEN	(* pointer to untagged or guid is untagged *)
			IF flag = 0 THEN flag := 1
			ELSIF (flag # 1) & (flag # 2) THEN err(225); flag := 0
			END
		ELSIF baseFlag = -12 THEN	(* pointer to java array is java array *)
			IF flag # 0 THEN err(225) END;
			flag := -12
		ELSIF baseFlag = -13 THEN	(* pointer to java string is java string *)
			IF flag # 0 THEN err(225) END;
			flag := -13
		END
	END PropagateArrPtrSysFlag;
	
	
	(* utf8 strings *)
	
	PROCEDURE PutUtf8* (VAR str: ARRAY OF SHORTCHAR; val: INTEGER; VAR idx: INTEGER);
	BEGIN
		ASSERT((val >= 0) & (val < 65536));
		IF val < 128 THEN
			str[idx] := SHORT(CHR(val)); INC(idx)
		ELSIF val < 2048 THEN
			str[idx] := SHORT(CHR(val DIV 64 + 192)); INC(idx);
			str[idx] := SHORT(CHR(val MOD 64 + 128)); INC(idx)
		ELSE
			str[idx] := SHORT(CHR(val DIV 4096 + 224)); INC(idx); 
			str[idx] := SHORT(CHR(val DIV 64 MOD 64 + 128)); INC(idx);
			str[idx] := SHORT(CHR(val MOD 64 + 128)); INC(idx)
		END
	END PutUtf8;
	
	PROCEDURE GetUtf8* (VAR str: ARRAY OF SHORTCHAR; VAR val, idx: INTEGER);
		VAR ch: SHORTCHAR;
	BEGIN
		ch := str[idx]; INC(idx);
		IF ch < 80X THEN
			val := ORD(ch)
		ELSIF ch < 0E0X THEN
			val := ORD(ch) - 192;
			ch := str[idx]; INC(idx); val := val * 64 + ORD(ch) - 128
		ELSE
			val := ORD(ch) - 224;
			ch := str[idx]; INC(idx); val := val * 64 + ORD(ch) - 128;
			ch := str[idx]; INC(idx); val := val * 64 + ORD(ch) - 128
		END
	END GetUtf8;

	PROCEDURE Mark* (n, pos: INTEGER);
	BEGIN
		IF (n >= 0) & ~((oberon IN options) & (n >= 181) & (n <= 190)) THEN
			noerr := FALSE;
			IF pos < 0 THEN pos := 0 END;
			IF (pos < lastpos) OR (lastpos + 9 < pos) THEN
				lastpos := pos;
				IF errors < maxErrors THEN
					errNo[errors] := n; errPos[errors] := pos
				END;
				INC(errors)
			END;
			IF trap IN options THEN HALT(100) END;
		ELSIF (n <= -700) & (errors < maxErrors) THEN
			errNo[errors] := -n; errPos[errors] := pos; INC(errors)
		END
	END Mark;
	
	PROCEDURE err* (n: INTEGER);
	BEGIN
		Mark(n, errpos)
	END err;

	(* fingerprinting *)

	PROCEDURE InitCrcTab;
		(* CRC32, high bit first, pre & post inverted *)
		CONST poly = {0, 1, 2, 4, 5, 7, 8, 10, 11, 12, 16, 22, 23, 26};	(* CRC32 polynom *)
		VAR x, c, i: INTEGER;
	BEGIN
		x := 0;
		WHILE x < 256 DO
			c := x * 1000000H; i := 0;
			WHILE i < 8 DO
				IF c < 0 THEN c := ORD(BITS(c * 2) / poly)
				ELSE c := c * 2
				END;
				INC(i)
			END;
			crc32tab[ORD(BITS(x) / BITS(255))] := ORD(BITS(c) / BITS(255));
			INC(x)
		END
	END InitCrcTab;
	
	PROCEDURE FPrint* (VAR fp: INTEGER; val: INTEGER);
		VAR c: INTEGER;
	BEGIN
(*
		fp := SYSTEM.ROT(ORD(BITS(fp) / BITS(val)), 1)	(* bad collision detection *)
*)
		(* CRC32, high bit first, pre & post inverted *)
		c := ORD(BITS(fp * 256) / BITS(crc32tab[ORD(BITS(fp DIV 1000000H) / BITS(val DIV 1000000H)) MOD 256]));
		c := ORD(BITS(c * 256) / BITS(crc32tab[ORD(BITS(c DIV 1000000H) / BITS(val DIV 10000H)) MOD 256]));
		c := ORD(BITS(c * 256) / BITS(crc32tab[ORD(BITS(c DIV 1000000H) / BITS(val DIV 100H)) MOD 256]));
		fp := ORD(BITS(c * 256) / BITS(crc32tab[ORD(BITS(c DIV 1000000H) / BITS(val)) MOD 256]));
	END FPrint;

	PROCEDURE FPrintSet* (VAR fp: INTEGER; set: SET);
	BEGIN FPrint(fp, ORD(set))
	END FPrintSet;

	PROCEDURE FPrintReal* (VAR fp: INTEGER; real: SHORTREAL);
	BEGIN FPrint(fp, SYSTEM.VAL(INTEGER, real))
	END FPrintReal;

	PROCEDURE FPrintLReal* (VAR fp: INTEGER; lr: REAL);
		VAR l, h: INTEGER;
	BEGIN
		FPrint(fp, LoWord(lr)); FPrint(fp, HiWord(lr))
	END FPrintLReal;

	PROCEDURE ChkSum (VAR fp: INTEGER; val: INTEGER);	(* symbolfile checksum *)
	BEGIN
		(* same as FPrint, 8 bit only *)
		fp := ORD(BITS(fp * 256) / BITS(crc32tab[ORD(BITS(fp DIV 1000000H) / BITS(val)) MOD 256]))
	END ChkSum;



	(* compact format *)
	
	PROCEDURE WriteLInt (w: Files.Writer; i: INTEGER);
	BEGIN
		ChkSum(checksum, i);
		w.WriteByte(SHORT(SHORT(i MOD 256))); i := i DIV 256;
		ChkSum(checksum, i);
		w.WriteByte(SHORT(SHORT(i MOD 256))); i := i DIV 256;
		ChkSum(checksum, i);
		w.WriteByte(SHORT(SHORT(i MOD 256))); i := i DIV 256;
		ChkSum(checksum, i);
		w.WriteByte(SHORT(SHORT(i MOD 256)))
	END WriteLInt;

	PROCEDURE ReadLInt (r: Files.Reader; VAR i: INTEGER);
		VAR b: BYTE; x: INTEGER;
	BEGIN
		r.ReadByte(b); x := b MOD 256;
		ChkSum(checksum, b);
		r.ReadByte(b); x := x + 100H * (b MOD 256);
		ChkSum(checksum, b);
		r.ReadByte(b); x := x + 10000H * (b MOD 256);
		ChkSum(checksum, b);
		r.ReadByte(b); i := x + 1000000H * b;
		ChkSum(checksum, b)
	END ReadLInt;

	PROCEDURE WriteNum (w: Files.Writer; i: INTEGER);
	BEGIN	(* old format of Oberon *)
		WHILE (i < -64) OR (i > 63) DO ChkSum(checksum, i MOD 128 - 128); w.WriteByte(SHORT(SHORT(i MOD 128 - 128))); i := i DIV 128 END;
		ChkSum(checksum, i MOD 128);
		w.WriteByte(SHORT(SHORT(i MOD 128)))
	END WriteNum;

	PROCEDURE ReadNum (r: Files.Reader; VAR i: INTEGER);
		VAR b: BYTE; s, y: INTEGER;
	BEGIN
		s := 0; y := 0; r.ReadByte(b);
		IF ~r.eof THEN ChkSum(checksum, b) END;
		WHILE b < 0 DO INC(y, ASH(b + 128, s)); INC(s, 7); r.ReadByte(b); ChkSum(checksum, b) END;
		i := ASH((b + 64) MOD 128 - 64, s) + y;
	END ReadNum;
	
	PROCEDURE WriteNumSet (w: Files.Writer; x: SET);
	BEGIN
		WriteNum(w, ORD(x))
	END WriteNumSet;

	PROCEDURE ReadNumSet (r: Files.Reader; VAR x: SET);
		VAR i: INTEGER;
	BEGIN
		ReadNum(r, i); x := BITS(i)
	END ReadNumSet;

	PROCEDURE WriteReal (w: Files.Writer; x: SHORTREAL);
	BEGIN
		WriteLInt(w, SYSTEM.VAL(INTEGER, x))
	END WriteReal;

	PROCEDURE ReadReal (r: Files.Reader; VAR x: SHORTREAL);
		VAR i: INTEGER;
	BEGIN
		ReadLInt(r, i); x := SYSTEM.VAL(SHORTREAL, i)
	END ReadReal;

	PROCEDURE WriteLReal (w: Files.Writer; x: REAL);
	BEGIN
		WriteLInt(w, LoWord(x)); WriteLInt(w, HiWord(x))
	END WriteLReal;

	PROCEDURE ReadLReal (r: Files.Reader; VAR x: REAL);
		VAR h, l: INTEGER;
	BEGIN
		ReadLInt(r, l); ReadLInt(r, h); x := Compound(l, h)
	END ReadLReal;


	(* read symbol file *)

	PROCEDURE SymRCh* (VAR ch: SHORTCHAR);
		VAR b: BYTE;
	BEGIN
		inSym.ReadByte(b); ch := SHORT(CHR(b));
		ChkSum(checksum, b)
	END SymRCh;
	
	PROCEDURE SymRInt* (): INTEGER;
		VAR k: INTEGER;
	BEGIN
		ReadNum(inSym, k); RETURN k
	END SymRInt;
		
	PROCEDURE SymRSet* (VAR s: SET);
	BEGIN
		ReadNumSet(inSym, s)
	END SymRSet;

	PROCEDURE SymRReal* (VAR r: SHORTREAL);
	BEGIN
		ReadReal(inSym, r)
	END SymRReal;
	
	PROCEDURE SymRLReal* (VAR lr: REAL);
	BEGIN
		ReadLReal(inSym, lr)
	END SymRLReal;
	
	PROCEDURE eofSF* (): BOOLEAN;
	BEGIN
		RETURN inSym.eof
	END eofSF;
	
	PROCEDURE OldSym* (VAR modName: ARRAY OF SHORTCHAR; VAR done: BOOLEAN);
		VAR tag: INTEGER; loc: Files.Locator; dir, name: Files.Name;
	BEGIN
		done := FALSE;
		IF modName = "@file" THEN
			oldSymFile := file
		ELSE
			name := modName$; Kernel.SplitName(name, dir, name);
			Kernel.MakeFileName(name, Kernel.symType); 
			loc := Files.dir.This(dir); loc := loc.This(symDir);
			oldSymFile := Files.dir.Old(loc, name, Files.shared);
			IF (oldSymFile = NIL) & (dir = "") THEN
				loc := Files.dir.This(SYSdir); loc := loc.This(symDir);
				oldSymFile := Files.dir.Old(loc, name, Files.shared)
			END
		END;
		IF oldSymFile # NIL THEN
			inSym := oldSymFile.NewReader(inSym);
			IF inSym # NIL THEN
				ReadLInt(inSym, tag);
				IF tag = SFtag THEN done := TRUE ELSE err(151) END
			END
		END
	END OldSym;

	PROCEDURE CloseOldSym*;
	BEGIN
		IF oldSymFile # NIL THEN oldSymFile.Close; oldSymFile := NIL END
	END CloseOldSym;


	(* write symbol file *)

	PROCEDURE SymWCh* (ch: SHORTCHAR);
	BEGIN
		ChkSum(checksum, ORD(ch));
		outSym.WriteByte(SHORT(ORD(ch)))
	END SymWCh;

	PROCEDURE SymWInt* (i: INTEGER);
	BEGIN
		WriteNum(outSym, i)
	END SymWInt;

	PROCEDURE SymWSet* (s: SET);
	BEGIN
		WriteNumSet(outSym, s)
	END SymWSet;

	PROCEDURE SymWReal* (VAR r: SHORTREAL);
	BEGIN
		WriteReal(outSym, r)
	END SymWReal;

	PROCEDURE SymWLReal* (VAR r: REAL);
	BEGIN
		WriteLReal(outSym, r)
	END SymWLReal;

	PROCEDURE SymReset*;
	BEGIN
		outSym.SetPos(4)
	END SymReset;

	PROCEDURE NewSym* (VAR modName: ARRAY OF SHORTCHAR);
		VAR loc: Files.Locator; dir: Files.Name;
	BEGIN
		ObjFName := modName$; Kernel.SplitName(ObjFName, dir, ObjFName);
		loc := Files.dir.This(dir); loc := loc.This(symDir);
		symFile := Files.dir.New(loc, Files.ask);
		IF symFile # NIL THEN
			outSym := symFile.NewWriter(NIL);
			WriteLInt(outSym, SFtag)
		ELSE
			err(153)
		END
	END NewSym;
	
	PROCEDURE RegisterNewSym*;
		VAR res: INTEGER; name: Files.Name;
	BEGIN
		IF symFile # NIL THEN
			name := ObjFName$;
			Kernel.MakeFileName(name, Kernel.symType);
			symFile.Register(name, Kernel.symType, Files.ask, res);
			symFile := NIL
		END
	END RegisterNewSym;
	
	PROCEDURE DeleteNewSym*;
	BEGIN
		IF symFile # NIL THEN symFile.Close; symFile := NIL END
	END DeleteNewSym;


	(* write object file *)

	PROCEDURE ObjW* (ch: SHORTCHAR);
	BEGIN
		outObj.WriteByte(SHORT(ORD(ch)))
	END ObjW;

	PROCEDURE ObjWNum* (i: INTEGER);
	BEGIN
		WriteNum(outObj, i)
	END ObjWNum;

	PROCEDURE ObjWInt (i: SHORTINT);
	BEGIN
		outObj.WriteByte(SHORT(SHORT(i MOD 256)));
		outObj.WriteByte(SHORT(SHORT(i DIV 256)))
	END ObjWInt;

	PROCEDURE ObjWLInt* (i: INTEGER);
	BEGIN
		ObjWInt(SHORT(i MOD 65536));
		ObjWInt(SHORT(i DIV 65536))
	END ObjWLInt;

	PROCEDURE ObjWBytes* (VAR bytes: ARRAY OF SHORTCHAR; n: INTEGER);
		TYPE P = POINTER TO ARRAY [untagged] 100000H OF BYTE;
		VAR p: P;
	BEGIN
		p := SYSTEM.VAL(P, SYSTEM.ADR(bytes));
		outObj.WriteBytes(p^, 0, n)
	END ObjWBytes;
	
	PROCEDURE ObjLen* (): INTEGER;
	BEGIN
		RETURN outObj.Pos()
	END ObjLen;
	
	PROCEDURE ObjSet* (pos: INTEGER);
	BEGIN
		outObj.SetPos(pos)
	END ObjSet;

	PROCEDURE NewObj* (VAR modName: ARRAY OF SHORTCHAR);
		VAR loc: Files.Locator; dir: Files.Name;
	BEGIN
		errpos := 0;
		ObjFName := modName$; Kernel.SplitName(ObjFName, dir, ObjFName);
		loc := Files.dir.This(dir); loc := loc.This(codeDir);
		objFile := Files.dir.New(loc, Files.ask);
		IF objFile # NIL THEN
			outObj := objFile.NewWriter(NIL);
			WriteLInt(outObj, OFtag)
		ELSE
			err(153)
		END
	END NewObj;

	PROCEDURE RegisterObj*;
		VAR res: INTEGER; name: Files.Name;
	BEGIN
		IF objFile # NIL THEN
			name := ObjFName$;
			Kernel.MakeFileName(name, Kernel.objType);
			objFile.Register(name, Kernel.objType, Files.ask, res);
			objFile := NIL; outObj := NIL
		END
	END RegisterObj;

	PROCEDURE DeleteObj*;
	BEGIN
		IF objFile # NIL THEN objFile.Close; objFile := NIL END
	END DeleteObj;


	PROCEDURE InitHost;
		VAR test: SHORTINT; lo: SHORTCHAR;
	BEGIN
		test := 1; SYSTEM.GET(SYSTEM.ADR(test), lo); LEHost := lo = 1X;
		InfReal := SYSTEM.VAL(SHORTREAL, InfRealPat);
		MinReal32 := SYSTEM.VAL(SHORTREAL, MinReal32Pat);
		MaxReal32 := SYSTEM.VAL(SHORTREAL, MaxReal32Pat);
		MinReal64 := Compound(MinReal64PatL, MinReal64PatH);
		MaxReal64 := Compound(MaxReal64PatL, MaxReal64PatH)
	END InitHost;

BEGIN
	InitCrcTab;
	InitHost
END Dev0CPM.