1#!/usr/bin/env perl
2# Copyright 2009 The Go Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style
4# license that can be found in the LICENSE file.
5
6# This program reads a file containing function prototypes
7# (like syscall_solaris.go) and generates system call bodies.
8# The prototypes are marked by lines beginning with "//sys"
9# and read like func declarations if //sys is replaced by func, but:
10#	* The parameter lists must give a name for each argument.
11#	  This includes return parameters.
12#	* The parameter lists must give a type for each argument:
13#	  the (x, y, z int) shorthand is not allowed.
14#	* If the return parameter is an error number, it must be named err.
15#	* If go func name needs to be different than its libc name,
16#	* or the function is not in libc, name could be specified
17#	* at the end, after "=" sign, like
18#	  //sys getsockopt(s int, level int, name int, val uintptr, vallen *_Socklen) (err error) = libsocket.getsockopt
19
20use strict;
21
22my $cmdline = "mksyscall_solaris.pl " . join(' ', @ARGV);
23my $errors = 0;
24my $_32bit = "";
25
26binmode STDOUT;
27
28if($ARGV[0] eq "-b32") {
29	$_32bit = "big-endian";
30	shift;
31} elsif($ARGV[0] eq "-l32") {
32	$_32bit = "little-endian";
33	shift;
34}
35
36if($ARGV[0] =~ /^-/) {
37	print STDERR "usage: mksyscall_solaris.pl [-b32 | -l32] [file ...]\n";
38	exit 1;
39}
40
41if($ENV{'GOARCH'} eq "" || $ENV{'GOOS'} eq "") {
42	print STDERR "GOARCH or GOOS not defined in environment\n";
43	exit 1;
44}
45
46sub parseparamlist($) {
47	my ($list) = @_;
48	$list =~ s/^\s*//;
49	$list =~ s/\s*$//;
50	if($list eq "") {
51		return ();
52	}
53	return split(/\s*,\s*/, $list);
54}
55
56sub parseparam($) {
57	my ($p) = @_;
58	if($p !~ /^(\S*) (\S*)$/) {
59		print STDERR "$ARGV:$.: malformed parameter: $p\n";
60		$errors = 1;
61		return ("xx", "int");
62	}
63	return ($1, $2);
64}
65
66my $package = "";
67my $text = "";
68my $dynimports = "";
69my $linknames = "";
70my @vars = ();
71while(<>) {
72	chomp;
73	s/\s+/ /g;
74	s/^\s+//;
75	s/\s+$//;
76	$package = $1 if !$package && /^package (\S+)$/;
77	my $nonblock = /^\/\/sysnb /;
78	next if !/^\/\/sys / && !$nonblock;
79
80	# Line must be of the form
81	#	func Open(path string, mode int, perm int) (fd int, err error)
82	# Split into name, in params, out params.
83	if(!/^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*(?:(\w*)\.)?(\w*))?$/) {
84		print STDERR "$ARGV:$.: malformed //sys declaration\n";
85		$errors = 1;
86		next;
87	}
88	my ($nb, $func, $in, $out, $modname, $sysname) = ($1, $2, $3, $4, $5, $6);
89
90	# Split argument lists on comma.
91	my @in = parseparamlist($in);
92	my @out = parseparamlist($out);
93
94	# So file name.
95	if($modname eq "") {
96		$modname = "libc";
97	}
98
99	# System call name.
100	if($sysname eq "") {
101		$sysname = "$func";
102	}
103
104	# System call pointer variable name.
105	my $sysvarname = "proc$sysname";
106
107	my $strconvfunc = "BytePtrFromString";
108	my $strconvtype = "*byte";
109
110	$sysname =~ y/A-Z/a-z/; # All libc functions are lowercase.
111
112	# Runtime import of function to allow cross-platform builds.
113	$dynimports .= "//go:cgo_import_dynamic libc_${sysname} ${sysname} \"$modname.so\"\n";
114	# Link symbol to proc address variable.
115	$linknames .= "//go:linkname ${sysvarname} libc_${sysname}\n";
116	# Library proc address variable.
117	push @vars, $sysvarname;
118
119	# Go function header.
120	$out = join(', ', @out);
121	if($out ne "") {
122		$out = " ($out)";
123	}
124	if($text ne "") {
125		$text .= "\n"
126	}
127	$text .= sprintf "func %s(%s)%s {\n", $func, join(', ', @in), $out;
128
129	# Check if err return available
130	my $errvar = "";
131	foreach my $p (@out) {
132		my ($name, $type) = parseparam($p);
133		if($type eq "error") {
134			$errvar = $name;
135			last;
136		}
137	}
138
139	# Prepare arguments to Syscall.
140	my @args = ();
141	my @uses = ();
142	my $n = 0;
143	foreach my $p (@in) {
144		my ($name, $type) = parseparam($p);
145		if($type =~ /^\*/) {
146			push @args, "uintptr(unsafe.Pointer($name))";
147		} elsif($type eq "string" && $errvar ne "") {
148			$text .= "\tvar _p$n $strconvtype\n";
149			$text .= "\t_p$n, $errvar = $strconvfunc($name)\n";
150			$text .= "\tif $errvar != nil {\n\t\treturn\n\t}\n";
151			push @args, "uintptr(unsafe.Pointer(_p$n))";
152			push @uses, "use(unsafe.Pointer(_p$n))";
153			$n++;
154		} elsif($type eq "string") {
155			print STDERR "$ARGV:$.: $func uses string arguments, but has no error return\n";
156			$text .= "\tvar _p$n $strconvtype\n";
157			$text .= "\t_p$n, _ = $strconvfunc($name)\n";
158			push @args, "uintptr(unsafe.Pointer(_p$n))";
159			push @uses, "use(unsafe.Pointer(_p$n))";
160			$n++;
161		} elsif($type =~ /^\[\](.*)/) {
162			# Convert slice into pointer, length.
163			# Have to be careful not to take address of &a[0] if len == 0:
164			# pass nil in that case.
165			$text .= "\tvar _p$n *$1\n";
166			$text .= "\tif len($name) > 0 {\n\t\t_p$n = \&$name\[0]\n\t}\n";
167			push @args, "uintptr(unsafe.Pointer(_p$n))", "uintptr(len($name))";
168			$n++;
169		} elsif($type eq "int64" && $_32bit ne "") {
170			if($_32bit eq "big-endian") {
171				push @args, "uintptr($name >> 32)", "uintptr($name)";
172			} else {
173				push @args, "uintptr($name)", "uintptr($name >> 32)";
174			}
175		} elsif($type eq "bool") {
176 			$text .= "\tvar _p$n uint32\n";
177			$text .= "\tif $name {\n\t\t_p$n = 1\n\t} else {\n\t\t_p$n = 0\n\t}\n";
178			push @args, "uintptr(_p$n)";
179			$n++;
180		} else {
181			push @args, "uintptr($name)";
182		}
183	}
184	my $nargs = @args;
185
186	# Determine which form to use; pad args with zeros.
187	my $asm = "sysvicall6";
188	if ($nonblock) {
189		$asm = "rawSysvicall6";
190	}
191	if(@args <= 6) {
192		while(@args < 6) {
193			push @args, "0";
194		}
195	} else {
196		print STDERR "$ARGV:$.: too many arguments to system call\n";
197	}
198
199	# Actual call.
200	my $args = join(', ', @args);
201	my $call = "$asm(uintptr(unsafe.Pointer(&$sysvarname)), $nargs, $args)";
202
203	# Assign return values.
204	my $body = "";
205	my $failexpr = "";
206	my @ret = ("_", "_", "_");
207	my @pout= ();
208	my $do_errno = 0;
209	for(my $i=0; $i<@out; $i++) {
210		my $p = $out[$i];
211		my ($name, $type) = parseparam($p);
212		my $reg = "";
213		if($name eq "err") {
214			$reg = "e1";
215			$ret[2] = $reg;
216			$do_errno = 1;
217		} else {
218			$reg = sprintf("r%d", $i);
219			$ret[$i] = $reg;
220		}
221		if($type eq "bool") {
222			$reg = "$reg != 0";
223		}
224		if($type eq "int64" && $_32bit ne "") {
225			# 64-bit number in r1:r0 or r0:r1.
226			if($i+2 > @out) {
227				print STDERR "$ARGV:$.: not enough registers for int64 return\n";
228			}
229			if($_32bit eq "big-endian") {
230				$reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i, $i+1);
231			} else {
232				$reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i+1, $i);
233			}
234			$ret[$i] = sprintf("r%d", $i);
235			$ret[$i+1] = sprintf("r%d", $i+1);
236		}
237		if($reg ne "e1") {
238			$body .= "\t$name = $type($reg)\n";
239		}
240	}
241	if ($ret[0] eq "_" && $ret[1] eq "_" && $ret[2] eq "_") {
242		$text .= "\t$call\n";
243	} else {
244		$text .= "\t$ret[0], $ret[1], $ret[2] := $call\n";
245	}
246	foreach my $use (@uses) {
247		$text .= "\t$use\n";
248	}
249	$text .= $body;
250
251	if ($do_errno) {
252		$text .= "\tif e1 != 0 {\n";
253		$text .= "\t\terr = e1\n";
254		$text .= "\t}\n";
255	}
256	$text .= "\treturn\n";
257	$text .= "}\n";
258}
259
260if($errors) {
261	exit 1;
262}
263
264print <<EOF;
265// $cmdline
266// MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
267
268// +build $ENV{'GOARCH'},$ENV{'GOOS'}
269
270package $package
271
272import (
273	"syscall"
274	"unsafe"
275)
276EOF
277
278print "import \"golang.org/x/sys/unix\"\n" if $package ne "unix";
279
280my $vardecls = "\t" . join(",\n\t", @vars);
281$vardecls .= " syscallFunc";
282
283chomp($_=<<EOF);
284
285$dynimports
286$linknames
287var (
288$vardecls
289)
290
291$text
292EOF
293print $_;
294exit 0;
295