#!/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 // Code generated by the command above; see README.md. 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;