github.com/DoctorWkt.pdp7-unix
1
0
Fork 0
mirror of https://github.com/DoctorWkt/pdp7-unix.git synced 2026-04-07 06:06:28 +00:00
Code Issues Releases Wiki Activity

I commented out most of the debug lines, and I now output the octal code

Browse Source 
along with the input line that generated it. There is code to use values
of defined constants as well as defined labels.
This commit is contained in:
Warren Toomey
2016-02-24 13:25:24 +10:00
parent f46777b272
commit 07c95bbe15
1 changed files with 35 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

60
tools/as7
View File

@@ -16,6 +16,8 @@ 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 current input line of code
my $stage = 1; # Pass one or pass two
@@ -42,7 +44,8 @@ foreach my $file (@ARGV) {
# Now print out the contents of memory
for my $i ( 0 .. $#Mem ) {
if (defined($Mem[$i])) {
printf("%06o: %06o\n", $i, $Mem[$i]);
printf("%06o: %06o\t%s\n",
$i, $Mem[$i], $Mline[$i] || "");
}
}
@@ -57,10 +60,11 @@ sub parse_file {
# Lose the end of line and any leading/trailing whitespace
# Discard any comments and preceding comment whitespace
chomp($line);
$origline= $line;
$line =~ s{^\s+}{};
$line =~ s{\s+$}{};
$line =~ s{\s*\".*}{};
print("=>$line<=\n");
#print("=>$line<=\n");
# Split into a section with possible labels and a
# section with definitely no labels. The ? makes the
@@ -88,7 +92,7 @@ sub parse_file {
foreach my $s (@stmntlist) {
parse_statement($s);
}
print("\n");
#print("\n");
}
close($IN);
}
@@ -98,9 +102,9 @@ sub parse_label {
my $label = shift;
# It's a relative label, save its current value in a list
if ( $label =~ m{\d+} ) {
if ( $label =~ m{^\d+$} ) {
push( @{ $Rlabel{$label} }, $Var{'.'} );
printf( "Pushing 0%o for relative label %s\n", $Var{'.'}, $label );
#printf( "Pushing 0%o for relative label %s\n", $Var{'.'}, $label );
return;
}
@@ -110,35 +114,37 @@ sub parse_label {
# Otherwise, save its value
$Label{$label} = $Var{'.'};
printf( "Set absolute label %s to 0%o\n", $label, $Label{$label} );
#printf( "Set absolute label %s to 0%o\n", $label, $Label{$label} );
}
sub parse_statement {
my $statement = shift;
my $location = $Var{'.'};
printf( "Location: 0%o\n", $location );
#printf( "Location: 0%o\n", $location );
# It's an assignment statement: lhs = rhs
if ( $statement =~ m{(\S+)\s*=\s*(\S+)} ) {
my $lhs = $1;
my $rhs = $2;
print("Assignment $statement\n");
#print("Assignment $statement\n");
# Save the expression's value into the variable
my $result = parse_expression($rhs);
die("expression $rhs has no value in assignment\n")
if ( !defined($result) );
printf( "Setting variable %s to 0%o\n", $lhs, $result );
#printf( "Setting variable %s to 0%o\n", $lhs, $result );
$Var{$lhs} = $result;
return;
}
# It's an expression, not a statement
# Get its value on pass two and save to memory
# Also save the input line that altered memory
if ( $stage == 2 ) {
my $val = parse_expression($statement);
$Mem[$location] = $val;
printf( "Saving 0%o into memory location 0%o\n", $val, $location );
$Mem[$location] = $val & 0777777;
$Mline[$location] = $origline;
#printf( "Saving 0%o into memory location 0%o\n", $val, $location );
}
# Move up to the next location in both passes
@@ -151,9 +157,14 @@ sub parse_statement {
sub parse_expression {
my $expression = shift;
# If it's a defined variable ( . , .. , etc.)
# return the value
return($Var{$expression})
if (defined($Var{$expression}));
# If it's a numeric literal, simply return it
if ( $expression =~ m{^-?\d+$} ) {
print("Returning numeric literal $expression\n");
#print("Returning numeric literal $expression\n");
return ( oct($expression) ) if ( $expression =~ m{^0} );
return ($expression);
}
@@ -286,12 +297,12 @@ sub parse_expression {
# Split the expression into two or three words separated by whitespace
my ( $word1, $word2, $word3 ) = split( /\s+/, $expression );
printf( "o>%s<o o>%s<o o>%s<o\n",
$word1 || "", $word2 || "", $word3 || "" );
#printf( "o>%s<o o>%s<o o>%s<o\n",
# $word1 || "", $word2 || "", $word3 || "" );
# This a defined instruction
if ( defined( $inst{$word1} ) ) {
printf( "Found the instruction %s: 0%o\n", $word1, $inst{$word1} );
#printf( "Found the instruction %s: 0%o\n", $word1, $inst{$word1} );
my $instruction = $inst{$word1};
# Is this an indirect instruction?
@@ -299,7 +310,7 @@ sub parse_expression {
# We have an expression for this instruction
if ( ( $stage == 2 ) && defined($word2) ) {
print(" and I need to parse $word2\n");
#print(" and I need to parse $word2\n");
my $val = parse_expression($word2);
die("Unable to parse $word2 on pass two\n") if ( !defined($val) );
$instruction |= $val | $indirect;
@@ -309,14 +320,14 @@ sub parse_expression {
# This is a defined label
if ( defined( $Label{$word1} ) ) {
printf( "Found the label %s: 0%o\n", $word1, $Label{$word1} );
#printf( "Found the label %s: 0%o\n", $word1, $Label{$word1} );
return ( $Label{$word1} );
}
# This is a defined relative label: digits followed by f or b
if ( $word1 =~ m{^(\d+)([fb])} ) {
my $val = find_relative_label( $1, $2 );
print("Got location $val for relative label $1$2\n");
#print("Got location $val for relative label $1$2\n");
return ($val);
}
@@ -326,7 +337,7 @@ sub parse_expression {
if ( !defined($sum) ) {
die("Unable to add $word1 on pass two\n") if ( !defined($sum) );
}
print("Did an addition and got $sum\n");
#print("Did an addition and got $sum\n");
return ($sum);
}
@@ -337,12 +348,11 @@ sub parse_expression {
die("Unable to subtract $word1 on pass two\n")
if ( !defined($diff) );
}
print("Did a subtraction and got $diff\n");
#print("Did a subtraction and got $diff\n");
return ($diff);
}
die("I have no idea what $expression is in pass two\n") if ( $stage == 2 );
return (1); # Doesn't matter on pass one
}
# Add two expression together
@@ -351,9 +361,9 @@ sub add {
my $val1 = parse_expression($a);
my $val2 = parse_expression($b);
print("Adding $val1 + $val2\n");
#print("Adding $val1 + $val2\n");
return (undef) if ( !defined($val1) || !defined($val2) );
print( " with a good value of ", $val1 + $val2, "\n" );
#print( " with a good value of ", $val1 + $val2, "\n" );
return ( $val1 + $val2 );
}
@@ -363,9 +373,9 @@ sub subtract {
my $val1 = parse_expression($a);
my $val2 = parse_expression($b);
print("Subtracting $val1 - $val2\n");
#print("Subtracting $val1 - $val2\n");
return (undef) if ( !defined($val1) || !defined($val2) );
print( " with a good value of ", $val1 - $val2, "\n" );
#print( " with a good value of ", $val1 - $val2, "\n" );
return ( $val1 - $val2 );
}