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-rwxr-xr-xsrc/syscall/mksyscall_libc.pl332
1 files changed, 332 insertions, 0 deletions
diff --git a/src/syscall/mksyscall_libc.pl b/src/syscall/mksyscall_libc.pl
new file mode 100755
index 0000000..5ceedc8
--- /dev/null
+++ b/src/syscall/mksyscall_libc.pl
@@ -0,0 +1,332 @@
+#!/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_libc.pl " . join(' ', @ARGV);
+my $errors = 0;
+my $_32bit = "";
+my $tags = ""; # build tags
+my $aix = 0;
+my $solaris = 0;
+
+binmode STDOUT;
+
+if($ARGV[0] eq "-b32") {
+ $_32bit = "big-endian";
+ shift;
+} elsif($ARGV[0] eq "-l32") {
+ $_32bit = "little-endian";
+ shift;
+}
+if($ARGV[0] eq "-aix") {
+ $aix = 1;
+ shift;
+}
+if($ARGV[0] eq "-solaris") {
+ $solaris = 1;
+ shift;
+}
+if($ARGV[0] eq "-tags") {
+ shift;
+ $tags = $ARGV[0];
+ shift;
+}
+
+
+if($ARGV[0] =~ /^-/) {
+ print STDERR "usage: mksyscall_libc.pl [-b32 | -l32] [-aix | -solaris] [-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;
+
+ my $syscalldot = "";
+ $syscalldot = "syscall." if $package ne "syscall";
+
+ # 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);
+
+ # Try in vain to keep people from editing this file.
+ # The theory is that they jump into the middle of the file
+ # without reading the header.
+ $text .= "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n";
+
+ # So file name.
+ if($aix) {
+ if($modname eq "") {
+ $modname = "libc.a/shr_64.o";
+ } else {
+ print STDERR "$func: only syscall using libc are available\n";
+ $errors = 1;
+ next;
+ }
+
+ }
+ if($solaris) {
+ if($modname eq "") {
+ $modname = "libc";
+ }
+ $modname .= ".so";
+
+ }
+
+ # System call name.
+ if($sysname eq "") {
+ $sysname = "$func";
+ }
+
+ # System call pointer variable name.
+ my $sysvarname = "libc_${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 ${sysvarname} ${sysname} \"$modname\"\n";
+ # Link symbol to proc address variable.
+ $linknames .= "//go:linkname ${sysvarname} ${sysvarname}\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;
+
+ my $asmfuncname="";
+ my $asmrawfuncname="";
+
+ if($aix){
+ $asmfuncname="syscall6";
+ $asmrawfuncname="rawSyscall6";
+ } else {
+ $asmfuncname="sysvicall6";
+ $asmrawfuncname="rawSysvicall6";
+ }
+
+ # Determine which form to use; pad args with zeros.
+ my $asm = "${syscalldot}${asmfuncname}";
+ if ($nonblock) {
+ $asm = "${syscalldot}${asmrawfuncname}";
+ }
+ if(@args <= 6) {
+ while(@args < 6) {
+ push @args, "0";
+ }
+ } else {
+ print STDERR "$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 = errnoErr(e1)\n";
+ $text .= "\t}\n";
+ }
+ $text .= "\treturn\n";
+ $text .= "}\n";
+}
+
+if($errors) {
+ exit 1;
+}
+
+print <<EOF;
+// $cmdline
+// Code generated by the command above; DO NOT EDIT.
+
+// +build $tags
+
+package $package
+
+import "unsafe"
+EOF
+
+print "import \"syscall\"\n" if $package ne "syscall";
+
+my $vardecls = "\t" . join(",\n\t", @vars);
+$vardecls .= " libcFunc";
+
+chomp($_=<<EOF);
+
+$dynimports
+$linknames
+type libcFunc uintptr
+
+var (
+$vardecls
+)
+
+$text
+EOF
+print $_;
+exit 0;