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