src/pkg/syscall/mksyscall_windows.pl - go - Git at Google

 #!/usr/bin/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_darwin.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 from it's winapi dll name,
 #	  the winapi name could be specified at the end, after "=" sign, like
 #	  //sys LoadLibrary(libname string) (handle uint32, err error) = LoadLibraryA
 #	* Each function that returns err needs to supply a condition,
 #	  that return value of winapi will be tested against to
 #	  detect failure. This would set err to windows "last-error",
 #	  otherwise it will be nil. The value can be provided
 #	  at end of //sys declaration, like
 #	  //sys LoadLibrary(libname string) (handle uint32, err error) [failretval==-1] = LoadLibraryA
 #	  and is [failretval==0] by default.

 use strict;

 my $cmdline = "mksyscall_windows.pl " . join(' ', @ARGV);
 my $errors = 0;
 my $_32bit = "";

 binmode STDOUT;

 if($ARGV[0] eq "-b32") {
 	$_32bit = "big-endian";
 	shift;
 } elsif($ARGV[0] eq "-l32") {
 	$_32bit = "little-endian";
 	shift;
 }

 if($ARGV[0] =~ /^-/) {
 	print STDERR "usage: mksyscall_windows.pl [-b32 | -l32] [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 $vars = "";
 my $mods = "";
 my $modnames = "";
 while(<>) {
 	chomp;
 	s/\s+/ /g;
 	s/^\s+//;
 	s/\s+$//;
 	$package = $1 if !$package && /^package (\S+)$/;
 	next if !/^\/\/sys /;

 	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 (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:\[failretval(.*)\])?\s*(?:=\s*(?:(\w*)\.)?(\w*))?$/) {
 		print STDERR "$ARGV:$.: malformed //sys declaration\n";
 		$errors = 1;
 		next;
 	}
 	my ($func, $in, $out, $failcond, $modname, $sysname) = ($1, $2, $3, $4, $5, $6);

 	# Split argument lists on comma.
 	my @in = parseparamlist($in);
 	my @out = parseparamlist($out);

 	# Dll file name.
 	if($modname eq "") {
 		$modname = "kernel32";
 	}
 	my $modvname = "mod$modname";
 	if($modnames !~ /$modname/) {
 		$modnames .= ".$modname";
 		$mods .= "\t$modvname = ${syscalldot}NewLazyDLL(\"$modname.dll\")\n";
 	}

 	# System call name.
 	if($sysname eq "") {
 		$sysname = "$func";
 	}

 	# System call pointer variable name.
 	my $sysvarname = "proc$sysname";

 	# Returned value when failed
 	if($failcond eq "") {
 		$failcond = "== 0";
 	}

 	# Decide which version of api is used: ascii or unicode.
 	my $strconvfunc = $sysname !~ /W$/ ? "StringBytePtr" : "StringToUTF16Ptr";

 	# Winapi proc address variable.
 	$vars .= "\t$sysvarname = $modvname.NewProc(\"$sysname\")\n";

 	# 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;

 	# Prepare arguments to Syscall.
 	my @args = ();
 	my $n = 0;
 	my @pin= ();
 	foreach my $p (@in) {
 		my ($name, $type) = parseparam($p);
 		if($type =~ /^\*/) {
 			push @args, "uintptr(unsafe.Pointer($name))";
 		} elsif($type eq "string") {
 			push @args, "uintptr(unsafe.Pointer($strconvfunc($name)))";
 		} elsif($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)";
 		}
 		push @pin, sprintf "\"%s=\", %s, ", $name, $name;
 	}
 	my $nargs = @args;

 	# Determine which form to use; pad args with zeros.
 	my $asm = "${syscalldot}Syscall";
 	if(@args <= 3) {
 		while(@args < 3) {
 			push @args, "0";
 		}
 	} elsif(@args <= 6) {
 		$asm = "${syscalldot}Syscall6";
 		while(@args < 6) {
 			push @args, "0";
 		}
 	} elsif(@args <= 9) {
 		$asm = "${syscalldot}Syscall9";
 		while(@args < 9) {
 			push @args, "0";
 		}
 	} elsif(@args <= 12) {
 		$asm = "${syscalldot}Syscall12";
 		while(@args < 12) {
 			push @args, "0";
 		}
 	} elsif(@args <= 15) {
 		$asm = "${syscalldot}Syscall15";
 		while(@args < 15) {
 			push @args, "0";
 		}
 	} else {
 		print STDERR "$ARGV:$.: too many arguments to system call\n";
 	}

 	# Actual call.
 	my $args = join(', ', @args);
 	my $call = "$asm($sysvarname.Addr(), $nargs, $args)";

 	# Assign return values.
 	my $body = "";
 	my $failexpr = "";
 	my @ret = ("_", "_", "_");
 	my @pout= ();
 	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;
 		} 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);
 		}
 		my $rettype = $type;
 		if($type =~ /^\*/) {
 			$reg = "unsafe.Pointer($reg)";
 			$rettype = "($rettype)";
 		}
 		if($i == 0) {
 			if($type eq "bool") {
 				$failexpr = "!$name";
 			} elsif($name eq "err") {
 				$ret[$i] = "r1";
 				$failexpr = "int(r1) $failcond";
 			} else {
 				$failexpr = "$name $failcond";
 			}
 		}
 		$failexpr =~ s/(=)([0-9A-Za-z\-+])/$1 $2/;  # gofmt compatible
 		if($name eq "err") {
 			# Set err to "last error" only if returned value indicate failure
 			$body .= "\tif $failexpr {\n";
 			$body .= "\t\tif $reg != 0 {\n";
 			$body .= "\t\t\t$name = $type($reg)\n";
 			$body .= "\t\t} else {\n";
 			$body .= "\t\t\t$name = ${syscalldot}EINVAL\n";
 			$body .= "\t\t}\n";
 			$body .= "\t}\n";
 		} elsif($rettype eq "error") {
 			# Set $reg to "error" only if returned value indicate failure
 			$body .= "\tif $reg != 0 {\n";
 			$body .= "\t\t$name = ${syscalldot}Errno($reg)\n";
 			$body .= "\t}\n";
 		} else {
 			$body .= "\t$name = $rettype($reg)\n";
 		}
 		push @pout, sprintf "\"%s=\", %s, ", $name, $name;
 	}
 	if ($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(0) {
 		$text .= sprintf 'print("SYSCALL: %s(", %s") (", %s")\n")%s', $func, join('", ", ', @pin), join('", ", ', @pout), "\n";
 	}

 	$text .= "\treturn\n";
 	$text .= "}\n";
 }

 if($errors) {
 	exit 1;
 }

 print <<EOF;
 // $cmdline
 // MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT

 package $package

 import "unsafe"
 EOF

 print "import \"syscall\"\n" if $package ne "syscall";

 print <<EOF;

 var (
 $mods
 $vars
 )

 $text

 EOF
 exit 0;
	#!/usr/bin/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_darwin.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 from it's winapi dll name,
	# the winapi name could be specified at the end, after "=" sign, like
	# //sys LoadLibrary(libname string) (handle uint32, err error) = LoadLibraryA
	# * Each function that returns err needs to supply a condition,
	# that return value of winapi will be tested against to
	# detect failure. This would set err to windows "last-error",
	# otherwise it will be nil. The value can be provided
	# at end of //sys declaration, like
	# //sys LoadLibrary(libname string) (handle uint32, err error) [failretval==-1] = LoadLibraryA
	# and is [failretval==0] by default.

	use strict;

	my $cmdline = "mksyscall_windows.pl " . join(' ', @ARGV);
	my $errors = 0;
	my $_32bit = "";

	binmode STDOUT;

	if($ARGV[0] eq "-b32") {
	$_32bit = "big-endian";
	shift;
	} elsif($ARGV[0] eq "-l32") {
	$_32bit = "little-endian";
	shift;
	}

	if($ARGV[0] =~ /^-/) {
	print STDERR "usage: mksyscall_windows.pl [-b32 \| -l32] [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 $vars = "";
	my $mods = "";
	my $modnames = "";
	while(<>) {
	chomp;
	s/\s+/ /g;
	s/^\s+//;
	s/\s+$//;
	$package = $1 if !$package && /^package (\S+)$/;
	next if !/^\/\/sys /;

	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 (\w+)\(([^()])\)\s(?:\(([^()]+)\))?\s(?:\[failretval(.)\])?\s(?:=\s(?:(\w)\.)?(\w))?$/) {
	print STDERR "$ARGV:$.: malformed //sys declaration\n";
	$errors = 1;
	next;
	}
	my ($func, $in, $out, $failcond, $modname, $sysname) = ($1, $2, $3, $4, $5, $6);

	# Split argument lists on comma.
	my @in = parseparamlist($in);
	my @out = parseparamlist($out);

	# Dll file name.
	if($modname eq "") {
	$modname = "kernel32";
	}
	my $modvname = "mod$modname";
	if($modnames !~ /$modname/) {
	$modnames .= ".$modname";
	$mods .= "\t$modvname = ${syscalldot}NewLazyDLL(\"$modname.dll\")\n";
	}

	# System call name.
	if($sysname eq "") {
	$sysname = "$func";
	}

	# System call pointer variable name.
	my $sysvarname = "proc$sysname";

	# Returned value when failed
	if($failcond eq "") {
	$failcond = "== 0";
	}

	# Decide which version of api is used: ascii or unicode.
	my $strconvfunc = $sysname !~ /W$/ ? "StringBytePtr" : "StringToUTF16Ptr";

	# Winapi proc address variable.
	$vars .= "\t$sysvarname = $modvname.NewProc(\"$sysname\")\n";

	# 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;

	# Prepare arguments to Syscall.
	my @args = ();
	my $n = 0;
	my @pin= ();
	foreach my $p (@in) {
	my ($name, $type) = parseparam($p);
	if($type =~ /^\*/) {
	push @args, "uintptr(unsafe.Pointer($name))";
	} elsif($type eq "string") {
	push @args, "uintptr(unsafe.Pointer($strconvfunc($name)))";
	} elsif($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)";
	}
	push @pin, sprintf "\"%s=\", %s, ", $name, $name;
	}
	my $nargs = @args;

	# Determine which form to use; pad args with zeros.
	my $asm = "${syscalldot}Syscall";
	if(@args <= 3) {
	while(@args < 3) {
	push @args, "0";
	}
	} elsif(@args <= 6) {
	$asm = "${syscalldot}Syscall6";
	while(@args < 6) {
	push @args, "0";
	}
	} elsif(@args <= 9) {
	$asm = "${syscalldot}Syscall9";
	while(@args < 9) {
	push @args, "0";
	}
	} elsif(@args <= 12) {
	$asm = "${syscalldot}Syscall12";
	while(@args < 12) {
	push @args, "0";
	}
	} elsif(@args <= 15) {
	$asm = "${syscalldot}Syscall15";
	while(@args < 15) {
	push @args, "0";
	}
	} else {
	print STDERR "$ARGV:$.: too many arguments to system call\n";
	}

	# Actual call.
	my $args = join(', ', @args);
	my $call = "$asm($sysvarname.Addr(), $nargs, $args)";

	# Assign return values.
	my $body = "";
	my $failexpr = "";
	my @ret = ("_", "_", "_");
	my @pout= ();
	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;
	} 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);
	}
	my $rettype = $type;
	if($type =~ /^\*/) {
	$reg = "unsafe.Pointer($reg)";
	$rettype = "($rettype)";
	}
	if($i == 0) {
	if($type eq "bool") {
	$failexpr = "!$name";
	} elsif($name eq "err") {
	$ret[$i] = "r1";
	$failexpr = "int(r1) $failcond";
	} else {
	$failexpr = "$name $failcond";
	}
	}
	$failexpr =~ s/(=)([0-9A-Za-z\-+])/$1 $2/; # gofmt compatible
	if($name eq "err") {
	# Set err to "last error" only if returned value indicate failure
	$body .= "\tif $failexpr {\n";
	$body .= "\t\tif $reg != 0 {\n";
	$body .= "\t\t\t$name = $type($reg)\n";
	$body .= "\t\t} else {\n";
	$body .= "\t\t\t$name = ${syscalldot}EINVAL\n";
	$body .= "\t\t}\n";
	$body .= "\t}\n";
	} elsif($rettype eq "error") {
	# Set $reg to "error" only if returned value indicate failure
	$body .= "\tif $reg != 0 {\n";
	$body .= "\t\t$name = ${syscalldot}Errno($reg)\n";
	$body .= "\t}\n";
	} else {
	$body .= "\t$name = $rettype($reg)\n";
	}
	push @pout, sprintf "\"%s=\", %s, ", $name, $name;
	}
	if ($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(0) {
	$text .= sprintf 'print("SYSCALL: %s(", %s") (", %s")\n")%s', $func, join('", ", ', @pin), join('", ", ', @pout), "\n";
	}

	$text .= "\treturn\n";
	$text .= "}\n";
	}

	if($errors) {
	exit 1;
	}

	print <<EOF;
	// $cmdline
	// MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT

	package $package

	import "unsafe"
	EOF

	print "import \"syscall\"\n" if $package ne "syscall";

	print <<EOF;

	var (
	$mods
	$vars
	)

	$text

	EOF
	exit 0;