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DoctorWkt.pdp7-unix/tools/as7
2016-03-01 01:43:24 -05:00

477 lines
14 KiB
Perl
Executable File

#!/usr/bin/perl
#
# Read in files of PDP-7 assembly code in Ken Thompon's as format
# and convert them into PDP-7 machine code
#
# (c) 2016 Warren Toomey, GPL3
# Tweaked by Phil Budne (line, expression parsing, "list" format)
#
use strict;
use warnings;
use Data::Dumper;
use Getopt::Long qw(GetOptions);
Getopt::Long::Configure qw(gnu_getopt);
### Global variables ###
my %Var; # Variables such as ., .., t
my %Label; # Labels that are defined once
my %Rlabel; # Relative labels, e.g. 1:, 2:
# with an array of locations for each label
my @Mem; # Actual PDP-7 memory locations
my @Mline; # Source lines associated with mem locations
my $origline; # The original current input line of code
my $line; # line being parsed
my $stage = 1; # Pass one or pass two
my $errors = 0; # set to non-zero on error
my $line_error = ' ';
my $file; # current file name
my $lineno; # current line number
## command line options
my $debug = 0; # Run in debug mode
my $symbols = 0; # dump symbols
my $format = 'a7out'; # output format
# keep this near the GetOptions call to make it easy to add documentation!
sub usage {
die("Usage: $0 [--debug] [--format=a7out|list ] file1.s [file2.s ...]\n")
}
### Main program ###
GetOptions(
'debug|d' => \$debug,
'format|f=s' => \$format,
) or usage();
usage() if ( @ARGV < 1 );
# predefine syscall and opcodes as variables
# start with the location counter at zero
%Var = (
'.' => 0,
save => 1, # saves core dump & user area!
getuid => 2,
open => 3,
read => 4,
write => 5,
creat => 6,
seek => 7,
tell => 8,
close => 9,
link => 10,
unlink => 11,
setuid => 12,
rename => 13,
exit => 14,
time => 15,
intrp => 16,
chdir => 17,
chmod => 18,
chown => 19,
# 20 removed
sysloc => 21, # return system addresses
# 22 removed
capt => 23, # capture display?
rele => 24, # release display?
status => 25, # "stat"
smes => 27,
rmes => 28,
fork => 29,
# List of instruction names and machine code values
# These come from https://raw.githubusercontent.com/simh/
# simtools/master/crossassemblers/macro7/macro7.c
# PLB: replace with symbols in "sop.s"?
sys => 0000000, # cal instruction (trap thru 020)
i => 0020000, # indirect bit
# memory reference instructions
dac => 0040000, # deposit AC
jms => 0100000, # jump to subroutine
dzm => 0140000, # deposit zero in memory
lac => 0200000, # load AC
xor => 0240000, # exclusive or
add => 0300000, # one's complement add
tad => 0340000, # two's complement add
xct => 0400000, # execute
isz => 0440000, # increment and skip if zero
and => 0500000, # AND with contents of Y
sad => 0540000, # skip if AC different from content of Y
jmp => 0600000, # jump to Y
# Type 177 Extended Arithmetic Element (EAE)
eae => 0640000, # base instruction (nop)
osc => 0640001, # OR SC into AC
omq => 0640002, # OR MQ into AC
cmq => 0640004, # Complement MQ
div => 0640323, # divide
norm => 0640444, # normalize, unsigned
lls => 0640600, # long left shift
als => 0640700, # AC shift
lrs => 0640500, # long right shift
lacs => 0641001, # load AC with SC
lacq => 0641002, # load AC with MQ
abs => 0644000, # absolute value
divs => 0644323, # divide, signed
clq => 0650000, # clear MQ
frdiv => 0650323, # fractional divide
lmq => 0652000, # load MQ from AC
mul => 0653122, # multiply
idiv => 0653323, # integer divide
idivs => 0657323, # integer divide, signed
frdivs => 0654323, # fractional divide, signed
muls => 0657122, # multiply, signed
norms => 0660444, # normalize, signed
gsm => 0664000, # get sign and magnitude
lrss => 0660500, # long right shift, signed
llss => 0660600, # long left shift, signed
alss => 0660700, # AC left shift, signed
# I/OT instructions
iot => 0700000, # base i/o transfer instruction
clsf => 0700001, # skip if RT clock overflow
iof => 0700002, # interrupts off (disable PIC)
ion => 0700042, # interrupts on (enable PIC)
iton => 0700062, # interrupt and trap on
clof => 0700004, # clear clock flag, disable clock
clon => 0700044, # clear clock flag, enable clock
rsf => 0700101, # skip if PTR flag set
rrb => 0700112, # clear PTR flag, OR buffer with AC
rcf => 0700102, # clear PTR flag
rsa => 0700104, # select PTR in alphanumeric mode
rsb => 0700144, # select PTR in binary mode
psf => 0700201, # skip if PTP flag set
pcf => 0700202, # clear PTP flag
psa => 0700204, # punch PTP in alphanumeric mode
psb => 0700244, # punch PTP in binary mode
ksf => 0700301, # skip if KBD flag set
krb => 0700312, # read KBD buffer
iors => 0700314, # input/output read status
tsf => 0700401, # skip if if TTY output flag set
tcf => 0700402, # clear TTY output flag
tls => 0700406, # load TTY output buffer and select
tts => 0703301, # Test Teleprinter and Skip
skp7 => 0703341, # skip if processor is PDP-7!
caf => 0703302, # Clear All Flags
crsf => 0706701, # skip if CDR is ready
crrb => 0706712, # read CDR buffer
crsa => 0706704, # select CDR alphanumeric mode
crsb => 0706744, # select CDR binary mode
# Operate Instructions
# Group 1 (OPR 1) instructions
opr => 0740000, # base operate instruction (nop)
nop => 0740000,
cma => 0740001, # complement accumulator
cml => 0740002, # complement link
oas => 0740004, # inclusive or accumulator switches
ral => 0740010, # rotate (ac, link) left
rar => 0740020, # rotate (ac, link) right
hlt => 0740040, # HALT
xx => 0740040,
sma => 0740100, # skip on minus accumulator
sza => 0740200, # skip on zero accumulator
snl => 0740400, # skip on non-zero link
skp => 0741000, # unconditional skip
spa => 0741100, # skip on positive accumulator
sna => 0741200, # skip on negative accumulator
szl => 0741400, # skip on zero link
rtl => 0742010, # rotate two left (ral*2)
rtr => 0742020, # rotate two right (rar*2)
cll => 0744000, # clear link
stl => 0744002, # set link
rcl => 0744010, # clear link, rotate left
rcr => 0744020, # clear link, rotate right
cla => 0750000, # clear accumulator
clc => 0750001, # clear and complement acc
las => 0750004, # load acc from switches
glk => 0750010, # get link
# Group 2 operate
law => 0760000, # load accumulator with (instruction)
lam => 0777777, # (load accumulator minus)
);
# Parse all the files
foreach my $file (@ARGV) {
parse_file($file);
}
# Now do it all again, pass two
$Var{'.'} = 0;
$stage = 2;
print("PASS 2\n") if ($debug);
foreach my $file (@ARGV) {
parse_file($file);
}
if ($format eq 'a7out') {
# print out the contents of memory
for my $i ( 0 .. $#Mem ) {
if ( defined( $Mem[$i] ) ) {
printf( "%06o: %06o\t%s\n", $i, $Mem[$i], $Mline[$i] || "" );
}
}
}
elsif ($format eq 'list') {
print "\n";
print "Labels:\n";
foreach my $key (sort keys %Label) {
printf("%-8.8s %#06o\n", $key, $Label{$key});
}
}
else {
die("unknown format $format");
}
exit($errors);
# report an assmebly error:
# sets error flag
# reports filename:lineno for emacs m-x compile
sub err {
$line_error = shift;
my $msg = shift;
$errors = 1; # exit status
if ($stage == 2) {
print STDERR "$file:$lineno: $msg\n";
print "$file:$lineno: $msg\n" if (! -t STDOUT);
}
return 0; # expression value
}
# Open and parse the given file
sub parse_file {
$file = shift;
open( my $IN, "<", $file ) || die("Cannot read $file: $!\n");
$lineno = 0;
while ( $line = <$IN> ) {
$lineno++;
chomp($line); # Lose the end of line
$origline = $line;
print "\t\t$line\n" if ($stage == 2 && $line ne '' && $format eq 'list');
parse_line();
}
close($IN);
}
# process a label and set its value to the location counter
# only called on pass 1;
# if called on pass 2, should check if values are identical
sub process_label {
my $label = shift;
# It's a relative label, save its current value in a list
if ( $label =~ m{^\d+$} ) {
push( @{ $Rlabel{$label} }, $Var{'.'} );
printf( "Pushing %#o for relative label %s\n", $Var{'.'}, $label ) if ($debug);
return;
}
# It's a textual label, check if it's been defined before
if ( defined( $Label{$label} ) ) {
err('M', "Label $label defined multiple times\n");
}
# Otherwise, save its value
$Label{$label} = $Var{'.'};
printf( "Set label %s to %#o\n", $label, $Label{$label} ) if ($debug);
}
# Blame Phil for this....
# parses global $line based on prefixes, nibbling of a bit at a time
# (: and ; can appear in char literals)
# handles multiple ';' separated words per line
sub parse_line {
while (1) {
$line_error = ' '; # clear listing error indicator
return if ($line eq '' || $line =~ m{^"}); # empty or comment: quit
# Lose any leading whitespace
$line =~ s{^\s*}{};
print "parse_line: '$line'\n" if ($debug);
while ($line =~ s{^([a-z0-9\.]+):\s*}{}) { # labels
my $label = $1;
# First pass: parse the labels
# (could check for same value on pass 2)
if ( $stage == 1 ) {
process_label($1);
}
}
if ( $line =~ s{^(\S+)\s*=}{}) { # assignment
my $lhs = $1;
my $word = parse_expression();
printf( "Setting variable %s to 0%o\n", $lhs, $word ) if ($debug);
$Var{$lhs} = $word;
printf("\t%06o %s\n", $word, $line_error) if ($stage == 2 && $format eq 'list');
}
else { # bare expression
# Get its value on pass two and save to memory
# Also save the input line that altered memory
my $word = parse_expression();
if ( $stage == 2 ) {
my $location = $Var{'.'};
$Mem[$location] = $word;
$Mline[$location] = $origline;
$origline = '';
if ($format eq 'list') {
printf( "%06o: %06o %s\n", $location, $word, $line_error);
}
}
# Move up to the next location in both passes
$Var{'.'}++;
} # expr
# eat trailing whitespace and ";", if any
$line =~ s{^\s*;?}{};
} # while
}
# Blame Phil for this bit too...
# Parse an expression off $line and return a PDP-7 word
# as a series of whitespace separated "syllables"
# ORed, added, or subtracted
sub parse_expression {
my $word = 0;
print "expression: '$line'\n" if ($debug);
while (1) {
my $syllable = 0;
my $op = '|';
$line =~ s{^\s+}{};
if ($line eq '' || $line =~ m{^[";]}) { # EOL ; and " terminate expr
printf("\tparse_expression => %#o\n", $word) if ($debug);
return $word;
}
print " '$line'\n" if ($debug);
if ($line =~ s{^-}{}) {
$op = '-';
}
elsif ($line =~ s{^\+}{}) {
$op = '+';
}
if ($line =~ s{^<(.)}{}) { # <char
$syllable = ord($1) << 9;
}
elsif ($line =~ s{^(.)>}{}) { # char>
$syllable = ord($1)
}
elsif ($line =~ s{^>(.)}{}) { # >char !!
$syllable = ord($1)
}
elsif ($line =~ s{^([a-z\.][a-z0-9\.]*)}{}) {
my $sym = $1;
print "\tsym: $sym\n" if ($debug);
if (defined($Var{$sym})) {
$syllable = $Var{$sym};
printf("\tvar: %s: %#o\n", $sym, $syllable) if ($debug);
}
elsif (defined($Label{$sym})) {
$syllable = $Label{$sym};
printf("\tlbl: %s: %#o\n", $sym, $syllable) if ($debug);
}
elsif ($stage == 2) {
err('U', "$sym not defined")
} # pass 2
} # symbol
elsif ( $line =~ s{^(\d+)([fb])}{} ) { # relative label
$syllable = find_relative_label( $1, $2 ) if ($stage == 2);
}
elsif ( $line =~ s{^(\d+)}{} ) {
my $value = $1;
if ( $value =~ m{^0} ) {
$syllable = oct($value);
}
else {
$syllable = $value + 0;
}
$syllable &= 0777777;
}
else {
# From the BSD fortune file:
# Ken Thompson has an automobile which he helped design.
# Unlike most automobiles, it has neither speedometer,
# nor gas gauge, nor any of the numerous idiot lights
# which plague the modern driver. Rather, if the driver
# makes any mistake, a giant "?" lights up in the center
# of the dashboard. "The experienced driver",
# he says, "will usually know what's wrong.
err('?', "huh? '$line'");
$line = ''; # abort processing
return $word;
}
if ($op eq '+') {
$word += $syllable;
}
elsif ($op eq '-') {
$word -= $syllable;
}
else {
$word |= $syllable;
}
$word &= 0777777;
printf("\tsyllable: %#o word: %#o\n", $syllable, $word) if ($debug);
}
}
# Given a relative label number and a direction,
# return the location of this relative label or
# die if we don't have one
sub find_relative_label {
my ( $label, $direction ) = @_;
my $curlocation = $Var{'.'};
# Error check: no labels at all
if ( !defined( $Rlabel{$label} ) ) {
return err('U', "relative label $label not defined\n");
}
# Get the list of possible locations for this label
my $locarray = $Rlabel{$label};
# Error check: no locations
return err('U', "No relative labels") if ( @{$locarray} == 0 );
if ( $direction eq 'f' ) {
# Search forward for first location larger then the current one
foreach my $reflocation ( @{$locarray} ) {
printf("forward %#o %#o\n", $reflocation, $curlocation) if ($debug);
return ($reflocation) if ( $reflocation > $curlocation );
}
}
else {
# Search backwards for first location smaller than the current one
foreach my $reflocation ( sort( { $b <=> $b } @{$locarray} ) ) {
printf("backward %#o %#o\n", $reflocation, $curlocation) if ($debug);
return ($reflocation) if ( $reflocation < $curlocation );
}
}
return err('U', "No relative label $label");
}