Serge Bazanski | cc25bdf | 2018-10-25 14:02:58 +0200 | [diff] [blame] | 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 | my $tags = ""; # build tags |
| 33 | |
| 34 | if($ARGV[0] eq "-b32") { |
| 35 | $_32bit = "big-endian"; |
| 36 | shift; |
| 37 | } elsif($ARGV[0] eq "-l32") { |
| 38 | $_32bit = "little-endian"; |
| 39 | shift; |
| 40 | } |
| 41 | if($ARGV[0] eq "-plan9") { |
| 42 | $plan9 = 1; |
| 43 | shift; |
| 44 | } |
| 45 | if($ARGV[0] eq "-openbsd") { |
| 46 | $openbsd = 1; |
| 47 | shift; |
| 48 | } |
| 49 | if($ARGV[0] eq "-netbsd") { |
| 50 | $netbsd = 1; |
| 51 | shift; |
| 52 | } |
| 53 | if($ARGV[0] eq "-dragonfly") { |
| 54 | $dragonfly = 1; |
| 55 | shift; |
| 56 | } |
| 57 | if($ARGV[0] eq "-arm") { |
| 58 | $arm = 1; |
| 59 | shift; |
| 60 | } |
| 61 | if($ARGV[0] eq "-tags") { |
| 62 | shift; |
| 63 | $tags = $ARGV[0]; |
| 64 | shift; |
| 65 | } |
| 66 | |
| 67 | if($ARGV[0] =~ /^-/) { |
| 68 | print STDERR "usage: mksyscall.pl [-b32 | -l32] [-tags x,y] [file ...]\n"; |
| 69 | exit 1; |
| 70 | } |
| 71 | |
| 72 | # Check that we are using the new build system if we should |
| 73 | if($ENV{'GOOS'} eq "linux" && $ENV{'GOARCH'} ne "sparc64") { |
| 74 | if($ENV{'GOLANG_SYS_BUILD'} ne "docker") { |
| 75 | print STDERR "In the new build system, mksyscall should not be called directly.\n"; |
| 76 | print STDERR "See README.md\n"; |
| 77 | exit 1; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | |
| 82 | sub parseparamlist($) { |
| 83 | my ($list) = @_; |
| 84 | $list =~ s/^\s*//; |
| 85 | $list =~ s/\s*$//; |
| 86 | if($list eq "") { |
| 87 | return (); |
| 88 | } |
| 89 | return split(/\s*,\s*/, $list); |
| 90 | } |
| 91 | |
| 92 | sub parseparam($) { |
| 93 | my ($p) = @_; |
| 94 | if($p !~ /^(\S*) (\S*)$/) { |
| 95 | print STDERR "$ARGV:$.: malformed parameter: $p\n"; |
| 96 | $errors = 1; |
| 97 | return ("xx", "int"); |
| 98 | } |
| 99 | return ($1, $2); |
| 100 | } |
| 101 | |
| 102 | my $text = ""; |
| 103 | while(<>) { |
| 104 | chomp; |
| 105 | s/\s+/ /g; |
| 106 | s/^\s+//; |
| 107 | s/\s+$//; |
| 108 | my $nonblock = /^\/\/sysnb /; |
| 109 | next if !/^\/\/sys / && !$nonblock; |
| 110 | |
| 111 | # Line must be of the form |
| 112 | # func Open(path string, mode int, perm int) (fd int, errno error) |
| 113 | # Split into name, in params, out params. |
| 114 | if(!/^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*((?i)SYS_[A-Z0-9_]+))?$/) { |
| 115 | print STDERR "$ARGV:$.: malformed //sys declaration\n"; |
| 116 | $errors = 1; |
| 117 | next; |
| 118 | } |
| 119 | my ($func, $in, $out, $sysname) = ($2, $3, $4, $5); |
| 120 | |
| 121 | # Split argument lists on comma. |
| 122 | my @in = parseparamlist($in); |
| 123 | my @out = parseparamlist($out); |
| 124 | |
| 125 | # Try in vain to keep people from editing this file. |
| 126 | # The theory is that they jump into the middle of the file |
| 127 | # without reading the header. |
| 128 | $text .= "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n"; |
| 129 | |
| 130 | # Go function header. |
| 131 | my $out_decl = @out ? sprintf(" (%s)", join(', ', @out)) : ""; |
| 132 | $text .= sprintf "func %s(%s)%s {\n", $func, join(', ', @in), $out_decl; |
| 133 | |
| 134 | # Check if err return available |
| 135 | my $errvar = ""; |
| 136 | foreach my $p (@out) { |
| 137 | my ($name, $type) = parseparam($p); |
| 138 | if($type eq "error") { |
| 139 | $errvar = $name; |
| 140 | last; |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | # Prepare arguments to Syscall. |
| 145 | my @args = (); |
| 146 | my $n = 0; |
| 147 | foreach my $p (@in) { |
| 148 | my ($name, $type) = parseparam($p); |
| 149 | if($type =~ /^\*/) { |
| 150 | push @args, "uintptr(unsafe.Pointer($name))"; |
| 151 | } elsif($type eq "string" && $errvar ne "") { |
| 152 | $text .= "\tvar _p$n *byte\n"; |
| 153 | $text .= "\t_p$n, $errvar = BytePtrFromString($name)\n"; |
| 154 | $text .= "\tif $errvar != nil {\n\t\treturn\n\t}\n"; |
| 155 | push @args, "uintptr(unsafe.Pointer(_p$n))"; |
| 156 | $n++; |
| 157 | } elsif($type eq "string") { |
| 158 | print STDERR "$ARGV:$.: $func uses string arguments, but has no error return\n"; |
| 159 | $text .= "\tvar _p$n *byte\n"; |
| 160 | $text .= "\t_p$n, _ = BytePtrFromString($name)\n"; |
| 161 | push @args, "uintptr(unsafe.Pointer(_p$n))"; |
| 162 | $n++; |
| 163 | } elsif($type =~ /^\[\](.*)/) { |
| 164 | # Convert slice into pointer, length. |
| 165 | # Have to be careful not to take address of &a[0] if len == 0: |
| 166 | # pass dummy pointer in that case. |
| 167 | # Used to pass nil, but some OSes or simulators reject write(fd, nil, 0). |
| 168 | $text .= "\tvar _p$n unsafe.Pointer\n"; |
| 169 | $text .= "\tif len($name) > 0 {\n\t\t_p$n = unsafe.Pointer(\&${name}[0])\n\t}"; |
| 170 | $text .= " else {\n\t\t_p$n = unsafe.Pointer(&_zero)\n\t}"; |
| 171 | $text .= "\n"; |
| 172 | push @args, "uintptr(_p$n)", "uintptr(len($name))"; |
| 173 | $n++; |
| 174 | } elsif($type eq "int64" && ($openbsd || $netbsd)) { |
| 175 | push @args, "0"; |
| 176 | if($_32bit eq "big-endian") { |
| 177 | push @args, "uintptr($name>>32)", "uintptr($name)"; |
| 178 | } elsif($_32bit eq "little-endian") { |
| 179 | push @args, "uintptr($name)", "uintptr($name>>32)"; |
| 180 | } else { |
| 181 | push @args, "uintptr($name)"; |
| 182 | } |
| 183 | } elsif($type eq "int64" && $dragonfly) { |
| 184 | if ($func !~ /^extp(read|write)/i) { |
| 185 | push @args, "0"; |
| 186 | } |
| 187 | if($_32bit eq "big-endian") { |
| 188 | push @args, "uintptr($name>>32)", "uintptr($name)"; |
| 189 | } elsif($_32bit eq "little-endian") { |
| 190 | push @args, "uintptr($name)", "uintptr($name>>32)"; |
| 191 | } else { |
| 192 | push @args, "uintptr($name)"; |
| 193 | } |
| 194 | } elsif($type eq "int64" && $_32bit ne "") { |
| 195 | if(@args % 2 && $arm) { |
| 196 | # arm abi specifies 64-bit argument uses |
| 197 | # (even, odd) pair |
| 198 | push @args, "0" |
| 199 | } |
| 200 | if($_32bit eq "big-endian") { |
| 201 | push @args, "uintptr($name>>32)", "uintptr($name)"; |
| 202 | } else { |
| 203 | push @args, "uintptr($name)", "uintptr($name>>32)"; |
| 204 | } |
| 205 | } else { |
| 206 | push @args, "uintptr($name)"; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | # Determine which form to use; pad args with zeros. |
| 211 | my $asm = "Syscall"; |
| 212 | if ($nonblock) { |
| 213 | if ($errvar eq "" && $ENV{'GOOS'} eq "linux") { |
| 214 | $asm = "RawSyscallNoError"; |
| 215 | } else { |
| 216 | $asm = "RawSyscall"; |
| 217 | } |
| 218 | } else { |
| 219 | if ($errvar eq "" && $ENV{'GOOS'} eq "linux") { |
| 220 | $asm = "SyscallNoError"; |
| 221 | } |
| 222 | } |
| 223 | if(@args <= 3) { |
| 224 | while(@args < 3) { |
| 225 | push @args, "0"; |
| 226 | } |
| 227 | } elsif(@args <= 6) { |
| 228 | $asm .= "6"; |
| 229 | while(@args < 6) { |
| 230 | push @args, "0"; |
| 231 | } |
| 232 | } elsif(@args <= 9) { |
| 233 | $asm .= "9"; |
| 234 | while(@args < 9) { |
| 235 | push @args, "0"; |
| 236 | } |
| 237 | } else { |
| 238 | print STDERR "$ARGV:$.: too many arguments to system call\n"; |
| 239 | } |
| 240 | |
| 241 | # System call number. |
| 242 | if($sysname eq "") { |
| 243 | $sysname = "SYS_$func"; |
| 244 | $sysname =~ s/([a-z])([A-Z])/${1}_$2/g; # turn FooBar into Foo_Bar |
| 245 | $sysname =~ y/a-z/A-Z/; |
| 246 | } |
| 247 | |
| 248 | # Actual call. |
| 249 | my $args = join(', ', @args); |
| 250 | my $call = "$asm($sysname, $args)"; |
| 251 | |
| 252 | # Assign return values. |
| 253 | my $body = ""; |
| 254 | my @ret = ("_", "_", "_"); |
| 255 | my $do_errno = 0; |
| 256 | for(my $i=0; $i<@out; $i++) { |
| 257 | my $p = $out[$i]; |
| 258 | my ($name, $type) = parseparam($p); |
| 259 | my $reg = ""; |
| 260 | if($name eq "err" && !$plan9) { |
| 261 | $reg = "e1"; |
| 262 | $ret[2] = $reg; |
| 263 | $do_errno = 1; |
| 264 | } elsif($name eq "err" && $plan9) { |
| 265 | $ret[0] = "r0"; |
| 266 | $ret[2] = "e1"; |
| 267 | next; |
| 268 | } else { |
| 269 | $reg = sprintf("r%d", $i); |
| 270 | $ret[$i] = $reg; |
| 271 | } |
| 272 | if($type eq "bool") { |
| 273 | $reg = "$reg != 0"; |
| 274 | } |
| 275 | if($type eq "int64" && $_32bit ne "") { |
| 276 | # 64-bit number in r1:r0 or r0:r1. |
| 277 | if($i+2 > @out) { |
| 278 | print STDERR "$ARGV:$.: not enough registers for int64 return\n"; |
| 279 | } |
| 280 | if($_32bit eq "big-endian") { |
| 281 | $reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i, $i+1); |
| 282 | } else { |
| 283 | $reg = sprintf("int64(r%d)<<32 | int64(r%d)", $i+1, $i); |
| 284 | } |
| 285 | $ret[$i] = sprintf("r%d", $i); |
| 286 | $ret[$i+1] = sprintf("r%d", $i+1); |
| 287 | } |
| 288 | if($reg ne "e1" || $plan9) { |
| 289 | $body .= "\t$name = $type($reg)\n"; |
| 290 | } |
| 291 | } |
| 292 | if ($ret[0] eq "_" && $ret[1] eq "_" && $ret[2] eq "_") { |
| 293 | $text .= "\t$call\n"; |
| 294 | } else { |
| 295 | if ($errvar eq "" && $ENV{'GOOS'} eq "linux") { |
| 296 | # raw syscall without error on Linux, see golang.org/issue/22924 |
| 297 | $text .= "\t$ret[0], $ret[1] := $call\n"; |
| 298 | } else { |
| 299 | $text .= "\t$ret[0], $ret[1], $ret[2] := $call\n"; |
| 300 | } |
| 301 | } |
| 302 | $text .= $body; |
| 303 | |
| 304 | if ($plan9 && $ret[2] eq "e1") { |
| 305 | $text .= "\tif int32(r0) == -1 {\n"; |
| 306 | $text .= "\t\terr = e1\n"; |
| 307 | $text .= "\t}\n"; |
| 308 | } elsif ($do_errno) { |
| 309 | $text .= "\tif e1 != 0 {\n"; |
| 310 | $text .= "\t\terr = errnoErr(e1)\n"; |
| 311 | $text .= "\t}\n"; |
| 312 | } |
| 313 | $text .= "\treturn\n"; |
| 314 | $text .= "}\n\n"; |
| 315 | } |
| 316 | |
| 317 | chomp $text; |
| 318 | chomp $text; |
| 319 | |
| 320 | if($errors) { |
| 321 | exit 1; |
| 322 | } |
| 323 | |
| 324 | print <<EOF; |
| 325 | // $cmdline |
| 326 | // Code generated by the command above; see README.md. DO NOT EDIT. |
| 327 | |
| 328 | // +build $tags |
| 329 | |
| 330 | package unix |
| 331 | |
| 332 | import ( |
| 333 | "syscall" |
| 334 | "unsafe" |
| 335 | ) |
| 336 | |
| 337 | var _ syscall.Errno |
| 338 | |
| 339 | $text |
| 340 | EOF |
| 341 | exit 0; |