Adding upstream version 1.17.13.upstream/1.17.13upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 399 insertions, 0 deletions

diff --git a/src/syscall/mksyscall.pl b/src/syscall/mksyscall.pl
new file mode 100755
index 0000000..758948b
--- /dev/null
+++ b/src/syscall/mksyscall.pl
@@ -0,0 +1,399 @@
+#!/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_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 errno.
+
+# A line beginning with //sysnb is like //sys, except that the
+# goroutine will not be suspended during the execution of the system
+# call.  This must only be used for system calls which can never
+# block, as otherwise the system call could cause all goroutines to
+# hang.
+
+use strict;
+
+my $cmdline = "mksyscall.pl " . join(' ', @ARGV);
+my $errors = 0;
+my $_32bit = "";
+my $plan9 = 0;
+my $darwin = 0;
+my $openbsd = 0;
+my $netbsd = 0;
+my $dragonfly = 0;
+my $arm = 0; # 64-bit value should use (even, odd)-pair
+my $libc = 0;
+my $tags = "";  # build tags
+my $newtags = ""; # new style build tags
+my $extraimports = "";
+
+if($ARGV[0] eq "-b32") {
+	$_32bit = "big-endian";
+	shift;
+} elsif($ARGV[0] eq "-l32") {
+	$_32bit = "little-endian";
+	shift;
+}
+if($ARGV[0] eq "-plan9") {
+	$plan9 = 1;
+	shift;
+}
+if($ARGV[0] eq "-darwin") {
+	$darwin = 1;
+	$libc = 1;
+	shift;
+}
+if($ARGV[0] eq "-openbsd") {
+	$openbsd = 1;
+	shift;
+}
+if($ARGV[0] eq "-netbsd") {
+	$netbsd = 1;
+	shift;
+}
+if($ARGV[0] eq "-dragonfly") {
+	$dragonfly = 1;
+	shift;
+}
+if($ARGV[0] eq "-arm") {
+	$arm = 1;
+	shift;
+}
+if($ARGV[0] eq "-libc") {
+	$libc = 1;
+	shift;
+}
+if($ARGV[0] eq "-tags") {
+	shift;
+	$tags = $ARGV[0];
+	shift;
+}
+
+if($ARGV[0] =~ /^-/) {
+	print STDERR "usage: mksyscall.pl [-b32 | -l32] [-tags x,y] [file ...]\n";
+	exit 1;
+}
+
+if($libc) {
+	$extraimports = 'import "internal/abi"';
+}
+
+sub parseparamlist($) {
+	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);
+}
+
+# set of trampolines we've already generated
+my %trampolines;
+
+my $text = "";
+while(<>) {
+	chomp;
+	s/\s+/ /g;
+	s/^\s+//;
+	s/\s+$//;
+	my $nonblock = /^\/\/sysnb /;
+	next if !/^\/\/sys / && !$nonblock;
+
+	# Line must be of the form
+	#	func Open(path string, mode int, perm int) (fd int, errno error)
+	# Split into name, in params, out params.
+	if(!/^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*((?i)_?SYS_[A-Z0-9_]+))?$/) {
+		print STDERR "$ARGV:$.: malformed //sys declaration\n";
+		$errors = 1;
+		next;
+	}
+	my ($func, $in, $out, $sysname) = ($2, $3, $4, $5);
+
+	# Split argument lists on comma.
+	my @in = parseparamlist($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.
+	$text .= "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n";
+
+	if (($darwin && $func eq "ptrace1") || (($openbsd && $libc) && $func eq "ptrace")) {
+		# The ptrace function is called from forkAndExecInChild where stack
+		# growth is forbidden.
+		$text .= "//go:nosplit\n"
+	}
+
+	# Go function header.
+	my $out_decl = @out ? sprintf(" (%s)", join(', ', @out)) : "";
+	$text .= sprintf "func %s(%s)%s {\n", $func, join(', ', @in), $out_decl;
+
+	# 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 *byte\n";
+			$text .= "\t_p$n, $errvar = BytePtrFromString($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 *byte\n";
+			$text .= "\t_p$n, _ = BytePtrFromString($name)\n";
+			push @args, "uintptr(unsafe.Pointer(_p$n))";
+			$n++;
+		} elsif($type =~ /^\[\](.*)/) {
+			# Convert slice into pointer, length.
+			# Have to be careful not to take address of &a[0] if len == 0:
+			# pass dummy pointer in that case.
+			# Used to pass nil, but some OSes or simulators reject write(fd, nil, 0).
+			$text .= "\tvar _p$n unsafe.Pointer\n";
+			$text .= "\tif len($name) > 0 {\n\t\t_p$n = unsafe.Pointer(\&${name}[0])\n\t}";
+			$text .= " else {\n\t\t_p$n = unsafe.Pointer(&_zero)\n\t}";
+			$text .= "\n";
+			push @args, "uintptr(_p$n)", "uintptr(len($name))";
+			$n++;
+		} elsif($type eq "int64" && ($openbsd || $netbsd)) {
+			if (!$libc) {
+				push @args, "0";
+			}
+			if($libc && $arm && @args % 2) {
+				# arm abi specifies 64 bit argument must be 64 bit aligned.
+				push @args, "0"
+			}
+			if($_32bit eq "big-endian") {
+				push @args, "uintptr($name>>32)", "uintptr($name)";
+			} elsif($_32bit eq "little-endian") {
+				push @args, "uintptr($name)", "uintptr($name>>32)";
+			} else {
+				push @args, "uintptr($name)";
+			}
+		} elsif($type eq "int64" && $dragonfly) {
+			if ($func !~ /^extp(read|write)/i) {
+				push @args, "0";
+			}
+			if($_32bit eq "big-endian") {
+				push @args, "uintptr($name>>32)", "uintptr($name)";
+			} elsif($_32bit eq "little-endian") {
+				push @args, "uintptr($name)", "uintptr($name>>32)";
+			} else {
+				push @args, "uintptr($name)";
+			}
+		} elsif($type eq "int64" && $_32bit ne "") {
+			if(@args % 2 && $arm) {
+				# arm abi specifies 64-bit argument uses
+				# (even, odd) pair
+				push @args, "0"
+			}
+			if($_32bit eq "big-endian") {
+				push @args, "uintptr($name>>32)", "uintptr($name)";
+			} else {
+				push @args, "uintptr($name)", "uintptr($name>>32)";
+			}
+		} else {
+			push @args, "uintptr($name)";
+		}
+	}
+
+	# Determine which form to use; pad args with zeros.
+	my $asm = "Syscall";
+	if ($nonblock) {
+		if ($errvar eq "" && $ENV{'GOOS'} eq "linux") {
+			$asm = "rawSyscallNoError";
+		} else {
+			$asm = "RawSyscall";
+		}
+	}
+	if ($libc) {
+		# Call unexported syscall functions (which take
+		# libc functions instead of syscall numbers).
+		$asm = lcfirst($asm);
+	}
+	if(@args <= 3) {
+		while(@args < 3) {
+			push @args, "0";
+		}
+	} elsif(@args <= 6) {
+		$asm .= "6";
+		while(@args < 6) {
+			push @args, "0";
+		}
+	} elsif(@args <= 9) {
+		$asm .= "9";
+		while(@args < 9) {
+			push @args, "0";
+		}
+	} else {
+		print STDERR "$ARGV:$.: too many arguments to system call\n";
+	}
+
+	if ($darwin || ($openbsd && $libc)) {
+		# Use extended versions for calls that generate a 64-bit result.
+		my ($name, $type) = parseparam($out[0]);
+		if ($type eq "int64" || ($type eq "uintptr" && $_32bit eq "")) {
+			$asm .= "X";
+		}
+	}
+
+	# System call number.
+	my $funcname = "";
+	if($sysname eq "") {
+		$sysname = "SYS_$func";
+		$sysname =~ s/([a-z])([A-Z])/${1}_$2/g;	# turn FooBar into Foo_Bar
+		$sysname =~ y/a-z/A-Z/;
+		if($libc) {
+			$sysname =~ y/A-Z/a-z/;
+			$sysname = substr $sysname, 4;
+			$funcname = "libc_$sysname";
+		}
+	}
+	if($libc) {
+		if($funcname eq "") {
+			$sysname = substr $sysname, 4;
+			$funcname = "libc_$sysname";
+		}
+		$sysname = "abi.FuncPCABI0(${funcname}_trampoline)";
+	}
+
+	# Actual call.
+	my $args = join(', ', @args);
+	my $call = "$asm($sysname, $args)";
+
+	# Assign return values.
+	my $body = "";
+	my @ret = ("_", "_", "_");
+	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" && !$plan9) {
+			$reg = "e1";
+			$ret[2] = $reg;
+			$do_errno = 1;
+		} elsif($name eq "err" && $plan9) {
+			$ret[0] = "r0";
+			$ret[2] = "e1";
+			next;
+		} 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" || $plan9) {
+			$body .= "\t$name = $type($reg)\n";
+		}
+	}
+	if ($ret[0] eq "_" && $ret[1] eq "_" && $ret[2] eq "_") {
+		$text .= "\t$call\n";
+	} else {
+		if ($errvar eq "" && $ENV{'GOOS'} eq "linux") {
+			# raw syscall without error on Linux, see golang.org/issue/22924
+			$text .= "\t$ret[0], $ret[1] := $call\n";
+		} else {
+			$text .= "\t$ret[0], $ret[1], $ret[2] := $call\n";
+		}
+	}
+	$text .= $body;
+
+	if ($plan9 && $ret[2] eq "e1") {
+		$text .= "\tif int32(r0) == -1 {\n";
+		$text .= "\t\terr = e1\n";
+		$text .= "\t}\n";
+	} elsif ($do_errno) {
+		$text .= "\tif e1 != 0 {\n";
+		$text .= "\t\terr = errnoErr(e1)\n";
+		$text .= "\t}\n";
+	}
+	$text .= "\treturn\n";
+	$text .= "}\n\n";
+	if($libc) {
+		if (not exists $trampolines{$funcname}) {
+			$trampolines{$funcname} = 1;
+			# The assembly trampoline that jumps to the libc routine.
+			$text .= "func ${funcname}_trampoline()\n\n";
+			# Tell the linker that funcname can be found in libSystem using varname without the libc_ prefix.
+			my $basename = substr $funcname, 5;
+			my $libc = "libc.so";
+			if ($darwin) {
+				$libc = "/usr/lib/libSystem.B.dylib";
+			}
+			$text .= "//go:cgo_import_dynamic $funcname $basename \"$libc\"\n\n";
+		}
+	}
+}
+
+chomp $text;
+chomp $text;
+
+if($errors) {
+	exit 1;
+}
+
+# TODO: this assumes tags are just simply comma separated. For now this is all the uses.
+$newtags = $tags =~ s/,/ && /r;
+
+print <<EOF;
+// $cmdline
+// Code generated by the command above; DO NOT EDIT.
+
+//go:build $newtags
+// +build $tags
+
+package syscall
+
+import "unsafe"
+$extraimports
+
+$text
+EOF
+exit 0;