#
# You may distribute under the terms of either the GNU General Public
# License or the Artistic License, as specified in the README file.
+
package B::Assembler;
use Exporter;
use B qw(ppname);
use B::Asmdata qw(%insn_data @insn_name);
use Config qw(%Config);
+require ByteLoader; # we just need its $VERSIOM
@ISA = qw(Exporter);
-@EXPORT_OK = qw(assemble_fh assemble_insn strip_comments
- parse_statement uncstring gen_header);
+@EXPORT_OK = qw(assemble_fh newasm endasm assemble);
+$VERSION = 0.04;
use strict;
my %opnumber;
$opnumber{$opname} = $i;
}
-my ($linenum, $errors);
+my($linenum, $errors, $out); # global state, set up by newasm
sub error {
my $str = shift;
my $debug = 0;
sub debug { $debug = shift }
+sub limcheck($$$$){
+ my( $val, $lo, $hi, $loc ) = @_;
+ if( $val < $lo || $hi < $val ){
+ error "argument for $loc outside [$lo, $hi]: $val";
+ $val = $hi;
+ }
+ return $val;
+}
+
#
# First define all the data conversion subs to which Asmdata will refer
#
$c = substr($c, 0, 1);
}
} else {
+ $arg = limcheck( $arg, 0, 0xff, 'U8' );
$c = chr($arg);
}
return $c;
}
-sub B::Asmdata::PUT_U16 { pack("S", $_[0]) }
-sub B::Asmdata::PUT_U32 { pack("L", $_[0]) }
-sub B::Asmdata::PUT_I32 { pack("L", $_[0]) }
+sub B::Asmdata::PUT_U16 {
+ my $arg = limcheck( $_[0], 0, 0xffff, 'U16' );
+ pack("S", $arg);
+}
+sub B::Asmdata::PUT_U32 {
+ my $arg = limcheck( $_[0], 0, 0xffffffff, 'U32' );
+ pack("L", $arg);
+}
+sub B::Asmdata::PUT_I32 {
+ my $arg = limcheck( $_[0], -0x80000000, 0x7fffffff, 'I32' );
+ pack("l", $arg);
+}
sub B::Asmdata::PUT_NV { sprintf("%s\0", $_[0]) } # "%lf" looses precision and pack('d',...)
# may not even be portable between compilers
-sub B::Asmdata::PUT_objindex { pack("L", $_[0]) } # could allow names here
+sub B::Asmdata::PUT_objindex { # could allow names here
+ my $arg = limcheck( $_[0], 0, 0xffffffff, '*index' );
+ pack("L", $arg);
+}
sub B::Asmdata::PUT_svindex { &B::Asmdata::PUT_objindex }
sub B::Asmdata::PUT_opindex { &B::Asmdata::PUT_objindex }
+sub B::Asmdata::PUT_pvindex { &B::Asmdata::PUT_objindex }
sub B::Asmdata::PUT_strconst {
my $arg = shift;
- $arg = uncstring($arg);
- if (!defined($arg)) {
+ my $str = uncstring($arg);
+ if (!defined($str)) {
error "bad string constant: $arg";
- return "";
+ $str = '';
}
- if ($arg =~ s/\0//g) {
+ if ($str =~ s/\0//g) {
error "string constant argument contains NUL: $arg";
+ $str = '';
}
- return $arg . "\0";
+ return $str . "\0";
}
sub B::Asmdata::PUT_pvcontents {
}
sub B::Asmdata::PUT_PV {
my $arg = shift;
- $arg = uncstring($arg);
- error "bad string argument: $arg" unless defined($arg);
- return pack("L", length($arg)) . $arg;
+ my $str = uncstring($arg);
+ if( ! defined($str) ){
+ error "bad string argument: $arg";
+ $str = '';
+ }
+ return pack("L", length($str)) . $str;
}
sub B::Asmdata::PUT_comment_t {
my $arg = shift;
return pack("S256", @ary);
}
# XXX Check this works
+# Note: $arg >> 32 is a no-op on 32-bit systems
sub B::Asmdata::PUT_IV64 {
my $arg = shift;
- return pack("LL", $arg >> 32, $arg & 0xffffffff);
+ return pack("LL", ($arg >> 16) >>16 , $arg & 0xffffffff);
+}
+
+sub B::Asmdata::PUT_IV {
+ $Config{ivsize} == 4 ? &B::Asmdata::PUT_I32 : &B::Asmdata::PUT_IV64;
}
my %unesc = (n => "\n", r => "\r", t => "\t", a => "\a",
sub strip_comments {
my $stmt = shift;
# Comments only allowed in instructions which don't take string arguments
+ # Treat string as a single line so .* eats \n characters.
$stmt =~ s{
- (?sx) # Snazzy extended regexp coming up. Also, treat
- # string as a single line so .* eats \n characters.
^\s* # Ignore leading whitespace
(
[^"]* # A double quote '"' indicates a string argument. If we
)
\s*\# # Any amount of whitespace plus the comment marker...
.*$ # ...which carries on to end-of-string.
- }{$1}; # Keep only the instruction and optional argument.
+ }{$1}sx; # Keep only the instruction and optional argument.
return $stmt;
}
-sub gen_header { # create the ByteCode header
- my $header = B::Asmdata::PUT_U32(0x43424c50); # 'PLBC'
- $header .= B::Asmdata::PUT_strconst($Config{archname});
+# create the ByteCode header: magic, archname, ByteLoader $VERSION, ivsize,
+# ptrsize, byteorder
+# nvtype is irrelevant (floats are stored as strings)
+# byteorder is strconst not U32 because of varying size issues
+
+sub gen_header {
+ my $header = "";
+
+ $header .= B::Asmdata::PUT_U32(0x43424c50); # 'PLBC'
+ $header .= B::Asmdata::PUT_strconst('"' . $Config{archname}. '"');
+ $header .= B::Asmdata::PUT_strconst(qq["$ByteLoader::VERSION"]);
$header .= B::Asmdata::PUT_U32($Config{ivsize});
- $header .= B::Asmdata::PUT_U32($Config{nvsize});
$header .= B::Asmdata::PUT_U32($Config{ptrsize});
- $header .= B::Asmdata::PUT_strconst($Config{byteorder}); # PV not U32 because
- # of varying size
+ $header .= B::Asmdata::PUT_strconst(sprintf(qq["0x%s"], $Config{byteorder}));
+
$header;
}
+
sub parse_statement {
my $stmt = shift;
my ($insn, $arg) = $stmt =~ m{
- (?sx)
^\s* # allow (but ignore) leading whitespace
(.*?) # Instruction continues up until...
(?: # ...an optional whitespace+argument group
\s+ # first whitespace.
(.*) # The argument is all the rest (newlines included).
)?$ # anchor at end-of-line
- };
+ }sx;
if (defined($arg)) {
if ($arg =~ s/^0x(?=[0-9a-fA-F]+$)//) {
$arg = hex($arg);
sub assemble_fh {
my ($fh, $out) = @_;
- my ($line, $insn, $arg);
- $linenum = 0;
- $errors = 0;
- &$out(gen_header());
+ my $line;
+ my $asm = newasm($out);
while ($line = <$fh>) {
- $linenum++;
- chomp $line;
- if ($debug) {
- my $quotedline = $line;
- $quotedline =~ s/\\/\\\\/g;
- $quotedline =~ s/"/\\"/g;
- &$out(assemble_insn("comment", qq("$quotedline")));
- }
- $line = strip_comments($line) or next;
- ($insn, $arg) = parse_statement($line);
- &$out(assemble_insn($insn, $arg));
- if ($debug) {
- &$out(assemble_insn("nop", undef));
- }
+ assemble($line);
}
+ endasm();
+}
+
+sub newasm {
+ my($outsub) = @_;
+
+ die "Invalid printing routine for B::Assembler\n" unless ref $outsub eq 'CODE';
+ die <<EOD if ref $out;
+Can't have multiple byteassembly sessions at once!
+ (perhaps you forgot an endasm()?)
+EOD
+
+ $linenum = $errors = 0;
+ $out = $outsub;
+
+ $out->(gen_header());
+}
+
+sub endasm {
if ($errors) {
- die "Assembly failed with $errors error(s)\n";
+ die "There were $errors assembly errors\n";
+ }
+ $linenum = $errors = $out = 0;
+}
+
+sub assemble {
+ my($line) = @_;
+ my ($insn, $arg);
+ $linenum++;
+ chomp $line;
+ if ($debug) {
+ my $quotedline = $line;
+ $quotedline =~ s/\\/\\\\/g;
+ $quotedline =~ s/"/\\"/g;
+ $out->(assemble_insn("comment", qq("$quotedline")));
+ }
+ if( $line = strip_comments($line) ){
+ ($insn, $arg) = parse_statement($line);
+ $out->(assemble_insn($insn, $arg));
+ if ($debug) {
+ $out->(assemble_insn("nop", undef));
+ }
}
}
=head1 SYNOPSIS
- use Assembler;
+ use B::Assembler qw(newasm endasm assemble);
+ newasm(\&printsub); # sets up for assembly
+ assemble($buf); # assembles one line
+ endasm(); # closes down
+
+ use B::Assembler qw(assemble_fh);
+ assemble_fh($fh, \&printsub); # assemble everything in $fh
=head1 DESCRIPTION
See F<ext/B/B/Assembler.pm>.
-=head1 AUTHOR
+=head1 AUTHORS
Malcolm Beattie, C<mbeattie@sable.ox.ac.uk>
+Per-statement interface by Benjamin Stuhl, C<sho_pi@hotmail.com>
=cut