#!/usr/bin/env perl
# Copyright 2009 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.
# This program reads a file containing function prototypes
# (like syscall_solaris.go) and generates system call bodies.
# The prototypes are marked by lines beginning with "//sys"
# and read like func declarations if //sys is replaced by func, but:
# * The parameter lists must give a name for each argument.
# This includes return parameters.
# * The parameter lists must give a type for each argument:
# the (x, y, z int) shorthand is not allowed.
# * If the return parameter is an error number, it must be named err.
# * If go func name needs to be different than its libc name,
# * or the function is not in libc, name could be specified
# * at the end, after "=" sign, like
# //sys getsockopt(s int, level int, name int, val uintptr, vallen *_Socklen) (err error) = libsocket.getsockopt
use strict;
my $cmdline = "mksyscall_solaris.pl " . join(' ', @ARGV);
my $errors = 0;
my $_32bit = "";
my $tags = ""; # build tags
binmode STDOUT;
if($ARGV[0] eq "-b32") {
$_32bit = "big-endian";
shift;
} elsif($ARGV[0] eq "-l32") {
$_32bit = "little-endian";
shift;
}
if($ARGV[0] eq "-tags") {
shift;
$tags = $ARGV[0];
shift;
}
if($ARGV[0] =~ /^-/) {
print STDERR "usage: mksyscall_solaris.pl [-b32 | -l32] [-tags x,y] [file ...]\n";
exit 1;
}
sub parseparamlist($) {
my ($list) = @_;
$list =~ s/^\s*//;
$list =~ s/\s*$//;
if($list eq "") {
return ();
}
return split(/\s*,\s*/, $list);
}
sub parseparam($) {
my ($p) = @_;
if($p !~ /^(\S*) (\S*)$/) {
print STDERR "$ARGV:$.: malformed parameter: $p\n";
$errors = 1;
return ("xx", "int");
}
return ($1, $2);
}
my $package = "";
my $text = "";
my $dynimports = "";
my $linknames = "";
my @vars = ();
while(<>) {
chomp;
s/\s+/ /g;
s/^\s+//;
s/\s+$//;
$package = $1 if !$package && /^package (\S+)$/;
my $nonblock = /^\/\/sysnb /;
next if !/^\/\/sys / && !$nonblock;
# Line must be of the form
# func Open(path string, mode int, perm int) (fd int, err error)
# Split into name, in params, out params.
if(!/^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*(?:(\w*)\.)?(\w*))?$/) {
print STDERR "$ARGV:$.: malformed //sys declaration\n";
$errors = 1;
next;
}
my ($nb, $func, $in, $out, $modname, $sysname) = ($1, $2, $3, $4, $5, $6);
# Split argument lists on comma.
my @in = parseparamlist($in);
my @out = parseparamlist($out);
# So file name.
if($modname eq "") {
$modname = "libc";
}
# System call name.
if($sysname eq "") {
$sysname = "$func";
}
# System call pointer variable name.
my $sysvarname = "proc$sysname";
my $strconvfunc = "BytePtrFromString";
my $strconvtype = "*byte";
$sysname =~ y/A-Z/a-z/; # All libc functions are lowercase.
# Runtime import of function to allow cross-platform builds.
$dynimports .= "//go:cgo_import_dynamic libc_${sysname} ${sysname} \"$modname.so\"\n";
# Link symbol to proc address variable.
$linknames .= "//go:linkname ${sysvarname} libc_${sysname}\n";
# Library proc address variable.
push @vars, $sysvarname;
# Go function header.
$out = join(', ', @out);
if($out ne "") {
$out = " ($out)";
}
if($text ne "") {
$text .= "\n"
}
$text .= sprintf "func %s(%s)%s {\n", $func, join(', ', @in), $out;
# Check if err return available
my $errvar = "";
foreach my $p (@out) {
my ($name, $type) = parseparam($p);
if($type eq "error") {
$errvar = $name;
last;
}
}
# Prepare arguments to Syscall.
my @args = ();
my $n = 0;
foreach my $p (@in) {
my ($name, $type) = parseparam($p);
if($type =~ /^\*/) {
push @args, "uintptr(unsafe.Pointer($name))";
} elsif($type eq "string" && $errvar ne "") {
$text .= "\tvar _p$n $strconvtype\n";
$text .= "\t_p$n, $errvar = $strconvfunc($name)\n";
$text .= "\tif $errvar != nil {\n\t\treturn\n\t}\n";
push @args, "uintptr(unsafe.Pointer(_p$n))";
$n++;
} elsif($type eq "string") {
print STDERR "$ARGV:$.: $func uses string arguments, but has no error return\n";
$text .= "\tvar _p$n $strconvtype\n";
$text .= "\t_p$n, _ = $strconvfunc($name)\n";
push @args, "uintptr(unsafe.Pointer(_p$n))";
$n++;
} elsif($type =~ /^\[\](.*)/) {
# Convert slice into pointer, length.
# Have to be careful not to take address of &a[0] if len == 0:
# pass nil in that case.
$text .= "\tvar _p$n *$1\n";
$text .= "\tif len($name) > 0 {\n\t\t_p$n = \&$name\[0]\n\t}\n";
push @args, "uintptr(unsafe.Pointer(_p$n))", "uintptr(len($name))";
$n++;
} elsif($type eq "int64" && $_32bit ne "") {
if($_32bit eq "big-endian") {
push @args, "uintptr($name >> 32)", "uintptr($name)";
} else {
push @args, "uintptr($name)", "uintptr($name >> 32)";
}
} elsif($type eq "bool") {
$text .= "\tvar _p$n uint32\n";
$text .= "\tif $name {\n\t\t_p$n = 1\n\t} else {\n\t\t_p$n = 0\n\t}\n";
push @args, "uintptr(_p$n)";
$n++;
} else {
push @args, "uintptr($name)";
}
}
my $nargs = @args;
# Determine which form to use; pad args with zeros.
my $asm = "sysvicall6";
if ($nonblock) {
$asm = "rawSysvicall6";
}
if(@args <= 6) {
while(@args < 6) {
push @args, "0";
}
} else {
print STDERR "$ARGV:$.: too many arguments to system call\n";
}
# Actual call.
my $args = join(', ', @args);
my $call = "$asm(uintptr(unsafe.Pointer(&$sysvarname)), $nargs, $args)";
# Assign return values.
my $body = "";
my $failexpr = "";
my @ret = ("_", "_", "_");
my @pout= ();
my $do_errno = 0;
for(my $i=0; $i<@out; $i++) {
my $p = $out[$i];
my ($name, $type) = parseparam($p);
my $reg = "";
if($name eq "err") {
$reg = "e1";
$ret[2] = $reg;
$do_errno = 1;
} else {
$reg = sprintf("r%d", $i);
$ret[$i] = $reg;
}
if($type eq "bool") {
$reg = "$reg != 0";
}
if($type eq "int64" && $_32bit ne "") {
# 64-bit number in r1:r0 or r0:r1.
if($i+2 > @out) {
print STDERR "$ARGV:$.: not enough registers for int64 return\n";
}
if($_32bit eq "big-endian") {
$reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i, $i+1);
} else {
$reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i+1, $i);
}
$ret[$i] = sprintf("r%d", $i);
$ret[$i+1] = sprintf("r%d", $i+1);
}
if($reg ne "e1") {
$body .= "\t$name = $type($reg)\n";
}
}
if ($ret[0] eq "_" && $ret[1] eq "_" && $ret[2] eq "_") {
$text .= "\t$call\n";
} else {
$text .= "\t$ret[0], $ret[1], $ret[2] := $call\n";
}
$text .= $body;
if ($do_errno) {
$text .= "\tif e1 != 0 {\n";
$text .= "\t\terr = e1\n";
$text .= "\t}\n";
}
$text .= "\treturn\n";
$text .= "}\n";
}
if($errors) {
exit 1;
}
print <<EOF;
// $cmdline
// MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
// +build $tags
package $package
import (
"syscall"
"unsafe"
)
EOF
print "import \"golang.org/x/sys/unix\"\n" if $package ne "unix";
my $vardecls = "\t" . join(",\n\t", @vars);
$vardecls .= " syscallFunc";
chomp($_=<<EOF);
$dynimports
$linknames
var (
$vardecls
)
$text
EOF
print $_;
exit 0;
