github.com/maenmax/kairep@v0.0.0-20210218001208-55bf3df36788/src/golang.org/x/sys/unix/mksyscall.pl (about) 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_darwin.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 errno. 15 16 # A line beginning with //sysnb is like //sys, except that the 17 # goroutine will not be suspended during the execution of the system 18 # call. This must only be used for system calls which can never 19 # block, as otherwise the system call could cause all goroutines to 20 # hang. 21 22 use strict; 23 24 my $cmdline = "mksyscall.pl " . join(' ', @ARGV); 25 my $errors = 0; 26 my $_32bit = ""; 27 my $plan9 = 0; 28 my $openbsd = 0; 29 my $netbsd = 0; 30 my $dragonfly = 0; 31 my $arm = 0; # 64-bit value should use (even, odd)-pair 32 33 if($ARGV[0] eq "-b32") { 34 $_32bit = "big-endian"; 35 shift; 36 } elsif($ARGV[0] eq "-l32") { 37 $_32bit = "little-endian"; 38 shift; 39 } 40 if($ARGV[0] eq "-plan9") { 41 $plan9 = 1; 42 shift; 43 } 44 if($ARGV[0] eq "-openbsd") { 45 $openbsd = 1; 46 shift; 47 } 48 if($ARGV[0] eq "-netbsd") { 49 $netbsd = 1; 50 shift; 51 } 52 if($ARGV[0] eq "-dragonfly") { 53 $dragonfly = 1; 54 shift; 55 } 56 if($ARGV[0] eq "-arm") { 57 $arm = 1; 58 shift; 59 } 60 61 if($ARGV[0] =~ /^-/) { 62 print STDERR "usage: mksyscall.pl [-b32 | -l32] [file ...]\n"; 63 exit 1; 64 } 65 66 if($ENV{'GOARCH'} eq "" || $ENV{'GOOS'} eq "") { 67 print STDERR "GOARCH or GOOS not defined in environment\n"; 68 exit 1; 69 } 70 71 sub parseparamlist($) { 72 my ($list) = @_; 73 $list =~ s/^\s*//; 74 $list =~ s/\s*$//; 75 if($list eq "") { 76 return (); 77 } 78 return split(/\s*,\s*/, $list); 79 } 80 81 sub parseparam($) { 82 my ($p) = @_; 83 if($p !~ /^(\S*) (\S*)$/) { 84 print STDERR "$ARGV:$.: malformed parameter: $p\n"; 85 $errors = 1; 86 return ("xx", "int"); 87 } 88 return ($1, $2); 89 } 90 91 my $text = ""; 92 while(<>) { 93 chomp; 94 s/\s+/ /g; 95 s/^\s+//; 96 s/\s+$//; 97 my $nonblock = /^\/\/sysnb /; 98 next if !/^\/\/sys / && !$nonblock; 99 100 # Line must be of the form 101 # func Open(path string, mode int, perm int) (fd int, errno error) 102 # Split into name, in params, out params. 103 if(!/^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*((?i)SYS_[A-Z0-9_]+))?$/) { 104 print STDERR "$ARGV:$.: malformed //sys declaration\n"; 105 $errors = 1; 106 next; 107 } 108 my ($func, $in, $out, $sysname) = ($2, $3, $4, $5); 109 110 # Split argument lists on comma. 111 my @in = parseparamlist($in); 112 my @out = parseparamlist($out); 113 114 # Try in vain to keep people from editing this file. 115 # The theory is that they jump into the middle of the file 116 # without reading the header. 117 $text .= "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n"; 118 119 # Go function header. 120 my $out_decl = @out ? sprintf(" (%s)", join(', ', @out)) : ""; 121 $text .= sprintf "func %s(%s)%s {\n", $func, join(', ', @in), $out_decl; 122 123 # Check if err return available 124 my $errvar = ""; 125 foreach my $p (@out) { 126 my ($name, $type) = parseparam($p); 127 if($type eq "error") { 128 $errvar = $name; 129 last; 130 } 131 } 132 133 # Prepare arguments to Syscall. 134 my @args = (); 135 my @uses = (); 136 my $n = 0; 137 foreach my $p (@in) { 138 my ($name, $type) = parseparam($p); 139 if($type =~ /^\*/) { 140 push @args, "uintptr(unsafe.Pointer($name))"; 141 } elsif($type eq "string" && $errvar ne "") { 142 $text .= "\tvar _p$n *byte\n"; 143 $text .= "\t_p$n, $errvar = BytePtrFromString($name)\n"; 144 $text .= "\tif $errvar != nil {\n\t\treturn\n\t}\n"; 145 push @args, "uintptr(unsafe.Pointer(_p$n))"; 146 push @uses, "use(unsafe.Pointer(_p$n))"; 147 $n++; 148 } elsif($type eq "string") { 149 print STDERR "$ARGV:$.: $func uses string arguments, but has no error return\n"; 150 $text .= "\tvar _p$n *byte\n"; 151 $text .= "\t_p$n, _ = BytePtrFromString($name)\n"; 152 push @args, "uintptr(unsafe.Pointer(_p$n))"; 153 push @uses, "use(unsafe.Pointer(_p$n))"; 154 $n++; 155 } elsif($type =~ /^\[\](.*)/) { 156 # Convert slice into pointer, length. 157 # Have to be careful not to take address of &a[0] if len == 0: 158 # pass dummy pointer in that case. 159 # Used to pass nil, but some OSes or simulators reject write(fd, nil, 0). 160 $text .= "\tvar _p$n unsafe.Pointer\n"; 161 $text .= "\tif len($name) > 0 {\n\t\t_p$n = unsafe.Pointer(\&${name}[0])\n\t}"; 162 $text .= " else {\n\t\t_p$n = unsafe.Pointer(&_zero)\n\t}"; 163 $text .= "\n"; 164 push @args, "uintptr(_p$n)", "uintptr(len($name))"; 165 $n++; 166 } elsif($type eq "int64" && ($openbsd || $netbsd)) { 167 push @args, "0"; 168 if($_32bit eq "big-endian") { 169 push @args, "uintptr($name>>32)", "uintptr($name)"; 170 } elsif($_32bit eq "little-endian") { 171 push @args, "uintptr($name)", "uintptr($name>>32)"; 172 } else { 173 push @args, "uintptr($name)"; 174 } 175 } elsif($type eq "int64" && $dragonfly) { 176 if ($func !~ /^extp(read|write)/i) { 177 push @args, "0"; 178 } 179 if($_32bit eq "big-endian") { 180 push @args, "uintptr($name>>32)", "uintptr($name)"; 181 } elsif($_32bit eq "little-endian") { 182 push @args, "uintptr($name)", "uintptr($name>>32)"; 183 } else { 184 push @args, "uintptr($name)"; 185 } 186 } elsif($type eq "int64" && $_32bit ne "") { 187 if(@args % 2 && $arm) { 188 # arm abi specifies 64-bit argument uses 189 # (even, odd) pair 190 push @args, "0" 191 } 192 if($_32bit eq "big-endian") { 193 push @args, "uintptr($name>>32)", "uintptr($name)"; 194 } else { 195 push @args, "uintptr($name)", "uintptr($name>>32)"; 196 } 197 } else { 198 push @args, "uintptr($name)"; 199 } 200 } 201 202 # Determine which form to use; pad args with zeros. 203 my $asm = "Syscall"; 204 if ($nonblock) { 205 $asm = "RawSyscall"; 206 } 207 if(@args <= 3) { 208 while(@args < 3) { 209 push @args, "0"; 210 } 211 } elsif(@args <= 6) { 212 $asm .= "6"; 213 while(@args < 6) { 214 push @args, "0"; 215 } 216 } elsif(@args <= 9) { 217 $asm .= "9"; 218 while(@args < 9) { 219 push @args, "0"; 220 } 221 } else { 222 print STDERR "$ARGV:$.: too many arguments to system call\n"; 223 } 224 225 # System call number. 226 if($sysname eq "") { 227 $sysname = "SYS_$func"; 228 $sysname =~ s/([a-z])([A-Z])/${1}_$2/g; # turn FooBar into Foo_Bar 229 $sysname =~ y/a-z/A-Z/; 230 } 231 232 # Actual call. 233 my $args = join(', ', @args); 234 my $call = "$asm($sysname, $args)"; 235 236 # Assign return values. 237 my $body = ""; 238 my @ret = ("_", "_", "_"); 239 my $do_errno = 0; 240 for(my $i=0; $i<@out; $i++) { 241 my $p = $out[$i]; 242 my ($name, $type) = parseparam($p); 243 my $reg = ""; 244 if($name eq "err" && !$plan9) { 245 $reg = "e1"; 246 $ret[2] = $reg; 247 $do_errno = 1; 248 } elsif($name eq "err" && $plan9) { 249 $ret[0] = "r0"; 250 $ret[2] = "e1"; 251 next; 252 } else { 253 $reg = sprintf("r%d", $i); 254 $ret[$i] = $reg; 255 } 256 if($type eq "bool") { 257 $reg = "$reg != 0"; 258 } 259 if($type eq "int64" && $_32bit ne "") { 260 # 64-bit number in r1:r0 or r0:r1. 261 if($i+2 > @out) { 262 print STDERR "$ARGV:$.: not enough registers for int64 return\n"; 263 } 264 if($_32bit eq "big-endian") { 265 $reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i, $i+1); 266 } else { 267 $reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i+1, $i); 268 } 269 $ret[$i] = sprintf("r%d", $i); 270 $ret[$i+1] = sprintf("r%d", $i+1); 271 } 272 if($reg ne "e1" || $plan9) { 273 $body .= "\t$name = $type($reg)\n"; 274 } 275 } 276 if ($ret[0] eq "_" && $ret[1] eq "_" && $ret[2] eq "_") { 277 $text .= "\t$call\n"; 278 } else { 279 $text .= "\t$ret[0], $ret[1], $ret[2] := $call\n"; 280 } 281 foreach my $use (@uses) { 282 $text .= "\t$use\n"; 283 } 284 $text .= $body; 285 286 if ($plan9 && $ret[2] eq "e1") { 287 $text .= "\tif int32(r0) == -1 {\n"; 288 $text .= "\t\terr = e1\n"; 289 $text .= "\t}\n"; 290 } elsif ($do_errno) { 291 $text .= "\tif e1 != 0 {\n"; 292 $text .= "\t\terr = errnoErr(e1)\n"; 293 $text .= "\t}\n"; 294 } 295 $text .= "\treturn\n"; 296 $text .= "}\n\n"; 297 } 298 299 chomp $text; 300 chomp $text; 301 302 if($errors) { 303 exit 1; 304 } 305 306 print <<EOF; 307 // $cmdline 308 // MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT 309 310 // +build $ENV{'GOARCH'},$ENV{'GOOS'} 311 312 package unix 313 314 import ( 315 "syscall" 316 "unsafe" 317 ) 318 319 var _ syscall.Errno 320 321 $text 322 EOF 323 exit 0;