Trailing-Edge
-
PDP-10 Archives
-
decus_20tap4_198111
-
decus/20-0122/xpl.doc
There are 2 other files named xpl.doc in the archive. Click here to see a list.
XPL. DOC
DOCUMENTATION FILE FOR XPL ON THE PDP-10.
R. W. HAY,
COMPUTER GROUP,
DEPARTMENT OF ELECTRICAL ENGINEERING,
UNIVERSITY OF TORONTO,
TORONTO, ONTARIO, CANADA.
AND
DATALINE SYSTEMS LIMITED,
175 BEDFORD RD.,
TORONTO, ONTARIO, CANADA.
VERSION 4.0
NOVEMBER 20, 1975.
HISTORY OF XPL ON THE PDP-10
----------------------------
THIS COMPILER WAS ORIGINALLY DESIGNED AND IMPLEMENTED ON THE PDP-10
BY R.L. BISBEY, UNIVERSITY OF SOUTHERN CALIFORNIA, IN 1971. VERSION
1 COULD COMPILE ITSELF, BUT WAS RESTRICTED IN THAT IT HAD NO GENERAL
RUN-TIME PACKAGE (IT JUST SET UP THOSE TEXT FILES NEEDED BY THE
COMPILER ITSELF), NOR WERE THE BUILT-IN PROCEDURES FILE, DATE, TIME,
AND INLINE IMPLEMENTED.
VERSION 2, DEVELOPED AT DATALINE SYSTEMS LTD., AND THE UNIVERSITY
OF TORONTO, BY R.W. HAY, HAS MUCH MORE EFFICIENT STRING CATENATION
AND NUMBER-TO-STRING CONVERSION ROUTINES, IMPLEMENTED THE BUILT-IN
PROCEDURES FILE, DATE, TIME, AND HAS ADDED FILENAME AND RUNTIME,
HAS A MORE EFFICIENT PROCEDURE CALLING SEQUENCE, AND PRODUCES A MORE
INFORMATIVE PROGRAM LISTING.
SEVERAL PROBLEMS IN VARIOUS PARTS OF THE COMPILER HAVE BEEN
FIXED, AND THE COMPILING SPEED (TO PRODUCE THE MACRO FORM) HAS BEEN
IMPROVED BY A FACTOR OF NEARLY 3. THIS SPEED IMPROVEMENT WAS MAINLY
ACCOMPLISHED BY:
- USING A HASH-CODING SCHEME FOR SYMBOL TABLE MANIPULATION,
- GENERATING THE STRING OF CHARACTERS REPRESENTING A NUMBER, IN
THE NUMBER-TO-STRING CONVERSION ROUTINE, ADJACENT TO THE LAST
STRING IN THE STRING AREA,
- IN THE CATENATION ROUTINE, CHECKING FOR THE SPECIAL CASES
(1) THE STRINGS ARE ALREADY ADJACENT, AND ONLY THE DESCRIPTOR
NEEDS CONSTRUCTION,
(2) THE "LEFT" STRING IS THE LAST STRING, AND THEREFORE ONLY
THE "RIGHT" STRING NEEDS TO BE PHYSICALLY MOVED,
- SIMPLIFYING THE PROCEDURE CALLING SEQUENCE TO THAT DESCRIB-
ED BELOW, FROM ONE WHERE ALL REGISTERS WERE SAVED AT EVERY
CALL, AND RESTORED AT EVERY RETURN.
VERSION 3 PRODUCES RELOCATABLE BINARY OUTPUT (AND, OPTIONALLY
MACRO-10 SOURCE AS WELL), AND COMPILES "COMPACTIFY" FROM A COMMON
LIBRARY SOURCE FILE. "INLINE" FACILITY IS ALSO IMPLEMENTED.
VERSION 4 RECOGNIZES THE COMPLETE XPL LANGUAGE, INCLUDING
TYPED PROCEDURES AND FACTORED DECLARATIONS.
WHEREVER POSSIBLE, THE CHARACTERISTICS OF XPL AS DESCRIBED IN
"A COMPILER GENERATOR" BY MCKEEMAN, HORNING, AND WORTMAN, HAVE BEEN
RETAINED, EVEN AT THE EXPENSE OF PDP-10 EFFICIENCY OR CONVENTION. FOR
EXAMPLE, THE DEFAULT RADIX FOR BIT STRINGS IS 16, RATHER THAN THE
MORE "NATURAL" 8.
CAVEATS
-------
THE COMPILER IS NOT WARRANTED IN ANY WAY.
THE EFFECTS OF VARIOUS RUN-TIME ERRORS ARE NOT KNOWN FROM
TESTING. THE RUNTIME PACKAGE WILL ABORT WITH A TERSE MESSAGE ON
CONDITIONS SUCH AS "ILLEGAL FILE NUMBER", OR "LOOKUP FAILURE".
PLANNED IMPROVEMENTS
--------------------
1. PROVISION OF A CROSS-REFERENCING FACILITY (A LA F40).
CURRENT STATE OF THE COMPILER AND ITS LANGUAGE
----------------------------------------------
1. THE COMPILER AND ITS RUNTIME PACKAGE ARE DESIGNED TO OPERATE UNDER
THE CONTROL OF THE STANDARD DIGITAL EQUIPMENT CORP. PDP-10
MONITOR.
2. RESTRICTIONS
------------
- COMPILER WILL NOT HANDLE LOWER-CASE CHARACTERS PROPERLY,
- MAX. NO. OF CASES IN A DO CASE = 175,
- MAX. NO. OF DECLARED SYMBOLS = 420,
- MAX. NO. OF MACROS (DECLARE LITERALLY) = 60,
- MAX. NO. OF STRING DESCRIPTORS = 1000.
3. IMPLEMENTATION CHARACTERISTICS
----------------------------------
- \ REPRESENTS THE "NOT" SYMBOL,
- ^ REPRESENTS THE "VERTICAL BAR" SYMBOL,
- _ REPRESENTS THE "UNDERSCORE" SYMBOL,
- BYTE SIZE IS 9 BITS, 4 BYTES TO THE 36-BIT WORD,
- BIT (1) TO BIT(9) MAP TO BYTE
BIT (10) TO BIT(36) MAP TO FIXED,
BIT(>36) MAPS TO CHARACTER (A STRING OF 9-BIT BYTES),
- DATE BUILT-IN PROCEDURE RETURNS THE DATE IN PDP-10
CONDENSED FORM, RIGHT-JUSTIFIED IN A 36-BIT WORD,
- TIME BUILT-IN PROCEDURE RETURNS THE TIME OF DAY IN
MILLISECONDS SINCE MIDNIGHT,
- RUNTIME BUILT-IN PROCEDURE RETURNS THE ACCUMULATED CPU TIME
FOR THE JOB IN MILLISECONDS,
- FILE PSEUDO-ARRAY IS DIFFERENT.
FILE (N)
CAUSES 1 36-BIT WORD TO BE RECEIVED FROM (PLACED IN) FILE N.
(0<N<16).
- THE RUNTIME PACKAGE INITIALIZATION SETS UP A FREE STRING AREA
OF AT LEAST 12000 BYTES AND A STACK (PUSH-DOWN LIST) OF 1000
WORDS. (THIS MAY BE EXCESSIVE, BUT IT WORKS).
- PROCEDURE CALLS (EXCEPT TO THE RUNTIME PACKAGE) ARE BY
PUSHJ 15,XXXX
RETURNS FROM PROCEDURES ARE BY
POPJ 15,0
- XPL PROGRAMS USE REGISTERS 1-11 (DECIMAL) FOR EXPRESSION
EVALUATION, ETC. FUNCTIONS RETURN VALUES IN REGISTER 0.
AT PROCEDURE CALLS, BUSY REGISTERS ARE SAVED IN THE STACK,
AND ARE RESTORED AFTER THE RETURN. E.G.:
PUSH 15,1
PUSH 15,2
PUSHJ 15,XXX
POP 15,2
POP 15,1
- CALLS TO THE RUN-TIME ROUTINES USE A DIFFERENT SEQUENCE:
(LOAD F,FILE #) (IF SPECIFIED)
(LOAD R,DATUM) (IF REQUIRED)
CODE R,0(F) (CODE IS USER UUO)
(STORE R,RESULT) (IF REQUIRED)
- THE COMPILED PROGRAM LOADS INTO TWO SEGMENTS:
LOW SEGMENT CONTAINS ALL DATA AND STRINGS,
HIGH SEGMENT CONTAINS ALL INSTRUCTIONS.
THE PROGRAM MAY BE "SSAVED"" TO OBTAIN SHARABLE HIGH SEGMENTS.
- INLINE BUILT-IN FUNCTION:
CALL IS
INLINE (OPCODE,AC,INDIRECT,INDEX,LOC);
WHERE
OPCODE, AC, INDIRECT, INDEX MUST ALL BE CONSTANTS,
AND LOC MAY BE EITHER A CONSTANT OR <VARIABLE>.
THE VALUE OF "INLINE" IS RECOGNIZED AS "FIXED"
IN REGISTER "AC".
E.G. CALL INLINE ("(3)200,2,0,0,I);
I = INLINE ("(3)201,3,0,0,23);
4. COMPILER SWITCHES (TOGGLES)
---------------------------
THE COMPILER CONTROL SWITCHES IMPLEMENTED, AND THEIR FUNCTIONS
ARE AS BELOW:
SWITCH INITIALLY FUNCTION WHEN TRUE
---------------------------------------------------------------
A FALSE PRODUCE MACRO-10 SOURCE FILE FOR PROGRAM
B FALSE LIST EMITTED DATA AND DESCRIPTORS
C FALSE LIST EMITTED CONSTANTS
D TRUE LIST MACROS AND COMPILER INFO AT END OF PROGRAM
E FALSE LIST EMITTED CODE
F FALSE (IF L = TRUE) LIST CODE, DATA, DESCRIPTOR ADDRESSES
K FALSE KILL LISTING OUTPUT (INHIBITS L BEING SET)
L TRUE PRODUCE LISTING WITH LINE #, CURRENT PROCEDURE, ETC
M FALSE LIST JUST IMAGE OF INPUT SOURCE (OVERRIDES L)
R FALSE DUMP PARSE STACK ON LISTING ON SYNTAX ERRORS
S TRUE (IF L = TRUE) LIST SYMBOL TABLE FOR EACH PROC.
X FALSE DO NOT INCLUDE CONTENTS OF 'XPL.LIB'
5. KNOWN PROBLEMS
--------------
- RUN-TIME ROUTINES DO NOT HANDLE ANY ERRORS, SUCH AS OVERFLOW,
STACK OVERFLOW, DIVIDE CHECK, ETC. THESE WILL EITHER BE
IGNORED OR PRODUCE A MONITOR ERROR MESSAGE.
- ANY ERROR ON ANY FILE WILL LOOK LIKE END-OF-FILE (WHICH CAUSES
A NULL STRING, OR A ZERO, TO BE RETURNED ON INPUT FILES).
OPERATING PROCEDURES
--------------------
THE COMPILER (XPL) ASKS FOR A FILENAME ON THE TERMINAL.
IT THEN OPENS FOUR FILES:
SYSIN:<FILENAME>.XPL XPL SOURCE
SYSOUT:<FILENAME>.LST GENERATED LISTING
DSK:<FILENAME>.REL GENERATED RELOCATABLE BINARY FILE
LIB:XPL.LIB SOURCE FILE CONTAINING "COMPACTIFY"
IF THE "X" SWITCH IS SPECIFIED IN THE TERMINAL RESPONSE, THEN THE
LIBRARY FILE (LIB:XPL.LIB) IS NOT PROCESSED. THIS SWITCH MAY ONLY
BE SPECIFIED FROM THE TERMINAL.
IF THE "A" SWITCH IS SPECIFIED IN THE TERMINAL RESPONSE, THEN THE
TWO FILES BELOW ARE ALSO OPENED:
DSK:<FILENAME>.MAC GENERATED MACRO ASSEMBLER SOURCE
DSK:<FILENAME>.TMP TEMPORARY WORK FILE
IF DEVICES "SYSIN", "SYSOUT", OR "LIB" DO NOT EXIST,
"DSK" IS USED.
SWITCHES MAY BE SPECIFIED IN THE TERMINAL RESPONSE BY
PRECEDING EACH SWITCH BY A "/".
E.G. TEST/A TO GENERATED MACRO-10 SOURCE
TEST/L TO LIST COMPACTIFY(NORMALLY
SUPPRESSED).
1. COMPILE THE XPL SOURCE:
.RUN DSK:XPL
FILE NAME TO BE COMPILED: XXXX
EXIT
^C
.
AT THIS POINT FILE XXXX.LST MAY BE PRINTED.
2. LOAD OR EXECUTE THE PROGRAM:
.EX XXXX,HMON
...
...
TO COMPILE THE COMPILER ITSELF, REPLACE "XXXX" BY "XCOM" ABOVE
AND RUN XPL IN 35K (RU XPL 35). (THIS IS TO REDUCE THE CPU TIME
WHEN COMPILING LARGE PROGRAMS.)
THE RUN-TIME ROUTINES
---------------------
"HMON" IS A PACKAGE DESIGNED TO SUPPORT I/O FUNCTIONS
FOR GENERAL XPL PROGRAMS. IT SUPPORTS BINARY I/O AS WELL
AS TEXT FILES, BOTH INPUT AND OUTPUT.
COMPLETELY GENERAL FILE DESCRIPTIONS MAY BE USED. UP TO 16 FILES MAY
BE OPEN AT ANY ONE TIME (ON LOGICAL NUMBERS 0-15).
FILE 0 IS INPUT ONLY, IN TEXT MODE.
FILE 1 IS OUTPUT ONLY, IN TEXT MODE.
FILE -1 IS TELETYPE, IN OR OUT, USING TTCALL UUOS.
-2 " " , OUTPUT, WITHOUT <CARRIAGE RETURN><LINE FEED>
AT THE END OF THE STRING TYPED.
<STRING> = INPUT(N); RETURNS THE NEXT LINE (TERMINATING WITH LF,
FF, ETC.) FROM THE FILE CURRENTLY OPEN AS
LOGICAL FILE N, AS A STRING. IF AT END-OF-FILE,
RETURN A NULL STRING, OTHERWISE RETURN AT LEAST
1 BLANK. N=1 IS ILLEGAL. IF N OMITTED, USE 0.
OUTPUT(N) = <STRING>; OUTPUT THE STRING TO THE FILE OPEN AS LOGICAL
FILE N. IF N=0, OR N IS OMITTED, USE N=1,BUT
WITH NO CARRIAGE CONTROL. IF N=1, FIRST CHAR
IN STRING IS USED AS CARRIAGE CONTROL INDICATOR.
<FIXED> = FILE(N); RETURNS THE NEXT 36-BIT WORD IN THE FILE OPEN
AS LOGICAL FILE N. IF AT END-OF-FILE, RETURN
ZERO. N=0 AND N=1 ARE ILLEGAL.
FILE(N) = <FIXED>; OUTPUTS THE 36-BIT VALUE AS THE NEXT WORD IN
THE FILE OPEN AS LOGICAL FILE N. N=0 AND N=1
ARE ILLEGAL.
FILENAME(N) = <STRING>; MAKES THE NEXT INPUT, OUTPUT, OR FILE OPER-
ATION ON LOGICAL FILE N USE THE FILE DESCRIBED
BY <STRING>. <STRING> IS A NORMAL PDP-10 FILE
DESCRIPTION:
DEVICE:NAME.EXTENSION[PROJ,PROG]
IF DEVICE IS OMITTED, USE "DSK"
IF NAME IS OMITTED, USE "XPLNN", NN=DECIMAL
FILE NUMBER, 00-15;
IF EXTENSION IS OMITTED, USE "DAT";
IF [PROJ,PROG] IS OMITTED, USE [0,0] (I.E.
DEFAULT TO OWN DIRECTORY).
N.B. (1) IF A NULL EXTENSION IS DESIRED, SPECIFY
AT LEAST 1 BLANK IN THE EXTENSION,
(2) IF [PROJ,PROG] IS INCLUDED, SPECIFY
THE FILENAME TOO.
FILES ARE ALWAYS CHECKED FOR CORRECT MODE AND DIRECTION BEFORE
EACH USE, AND WILL BE CLOSED AND REWOUND IF NECESSARY.
FILES 0 AND 1 HAVE AN INITIAL DEVICE SPECIFICATION OF "SYSIN"
AND "SYSOUT", RESPECTIVELY, BUT THIS IS CHANGED TO "DSK" IF EITHER
THESE DEVICES ARE NOT AVAILABLE, OR FILENAME IS CALLED TO SPECIFY
ANYTHING FOR THESE FILES.
AT THIS TIME, NO DELETE OR RENAME CAPABILITY EXISTS FOR XPL
PROGRAMS.