wasi: support building internal/sysfs with TinyGo (#2160)

Signed-off-by: gram <git@orsinium.dev>
Signed-off-by: Edoardo Vacchi <evacchi@users.noreply.github.com>
Co-authored-by: Edoardo Vacchi <evacchi@users.noreply.github.com>

internal/sysfs/dirfs.go

@@ -86,12 +86,6 @@ func (d *dirFS) Readlink(path string) (string, experimentalsys.Errno) {
 	return platform.ToPosixPath(dst), 0
 }
 
-// Link implements the same method as documented on sys.FS
-func (d *dirFS) Link(oldName, newName string) experimentalsys.Errno {
-	err := os.Link(d.join(oldName), d.join(newName))
-	return experimentalsys.UnwrapOSError(err)
-}
-
 // Rmdir implements the same method as documented on sys.FS
 func (d *dirFS) Rmdir(path string) experimentalsys.Errno {
 	return rmdir(d.join(path))

internal/sysfs/dirfs_link_supported.go

@@ -0,0 +1,15 @@
+//go:build !tinygo
+
+package sysfs
+
+import (
+	"os"
+
+	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
+)
+
+// Link implements the same method as documented on sys.FS
+func (d *dirFS) Link(oldName, newName string) experimentalsys.Errno {
+	err := os.Link(d.join(oldName), d.join(newName))
+	return experimentalsys.UnwrapOSError(err)
+}

internal/sysfs/dirfs_link_unsupported.go

@@ -0,0 +1,12 @@
+//go:build tinygo
+
+package sysfs
+
+import (
+	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
+)
+
+// Link implements the same method as documented on sys.FS
+func (d *dirFS) Link(oldName, newName string) experimentalsys.Errno {
+	return experimentalsys.ENOSYS
+}

internal/sysfs/sock.go

@@ -58,25 +58,6 @@ func newDefaultTCPListenerFile(tl *net.TCPListener) socketapi.TCPSock {
 	return &tcpListenerFile{tl: tl}
 }
 
-// Accept implements the same method as documented on socketapi.TCPSock
-func (f *tcpListenerFile) Accept() (socketapi.TCPConn, experimentalsys.Errno) {
-	// Ensure we have an incoming connection, otherwise return immediately.
-	if f.nonblock {
-		if ready, errno := _pollSock(f.tl, fsapi.POLLIN, 0); !ready || errno != 0 {
-			return nil, experimentalsys.EAGAIN
-		}
-	}
-
-	// Accept normally blocks goroutines, but we
-	// made sure that we have an incoming connection,
-	// so we should be safe.
-	if conn, err := f.tl.Accept(); err != nil {
-		return nil, experimentalsys.UnwrapOSError(err)
-	} else {
-		return newTcpConn(conn.(*net.TCPConn)), 0
-	}
-}
-
 // Close implements the same method as documented on experimentalsys.File
 func (f *tcpListenerFile) Close() experimentalsys.Errno {
 	if !f.closed {
@@ -90,15 +71,6 @@ func (f *tcpListenerFile) Addr() *net.TCPAddr {
 	return f.tl.Addr().(*net.TCPAddr)
 }
 
-// SetNonblock implements the same method as documented on fsapi.File
-func (f *tcpListenerFile) SetNonblock(enabled bool) (errno experimentalsys.Errno) {
-	f.nonblock = enabled
-	_, errno = syscallConnControl(f.tl, func(fd uintptr) (int, experimentalsys.Errno) {
-		return 0, setNonblockSocket(fd, enabled)
-	})
-	return
-}
-
 // IsNonblock implements the same method as documented on fsapi.File
 func (f *tcpListenerFile) IsNonblock() bool {
 	return f.nonblock
@@ -182,23 +154,6 @@ func (f *tcpConnFile) Recvfrom(p []byte, flags int) (n int, errno experimentalsy
 	})
 }
 
-// Shutdown implements the same method as documented on experimentalsys.Conn
-func (f *tcpConnFile) Shutdown(how int) experimentalsys.Errno {
-	// FIXME: can userland shutdown listeners?
-	var err error
-	switch how {
-	case socketapi.SHUT_RD:
-		err = f.tc.CloseRead()
-	case socketapi.SHUT_WR:
-		err = f.tc.CloseWrite()
-	case socketapi.SHUT_RDWR:
-		return f.close()
-	default:
-		return experimentalsys.EINVAL
-	}
-	return experimentalsys.UnwrapOSError(err)
-}
-
 // Close implements the same method as documented on experimentalsys.File
 func (f *tcpConnFile) Close() experimentalsys.Errno {
 	return f.close()

internal/sysfs/sock_supported.go

@@ -1,13 +1,61 @@
-//go:build linux || darwin || windows
+//go:build (linux || darwin || windows) && !tinygo
 
 package sysfs
 
 import (
+	"net"
 	"syscall"
 
 	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
+	"github.com/tetratelabs/wazero/internal/fsapi"
+	socketapi "github.com/tetratelabs/wazero/internal/sock"
 )
 
+// Accept implements the same method as documented on socketapi.TCPSock
+func (f *tcpListenerFile) Accept() (socketapi.TCPConn, experimentalsys.Errno) {
+	// Ensure we have an incoming connection, otherwise return immediately.
+	if f.nonblock {
+		if ready, errno := _pollSock(f.tl, fsapi.POLLIN, 0); !ready || errno != 0 {
+			return nil, experimentalsys.EAGAIN
+		}
+	}
+
+	// Accept normally blocks goroutines, but we
+	// made sure that we have an incoming connection,
+	// so we should be safe.
+	if conn, err := f.tl.Accept(); err != nil {
+		return nil, experimentalsys.UnwrapOSError(err)
+	} else {
+		return newTcpConn(conn.(*net.TCPConn)), 0
+	}
+}
+
+// SetNonblock implements the same method as documented on fsapi.File
+func (f *tcpListenerFile) SetNonblock(enabled bool) (errno experimentalsys.Errno) {
+	f.nonblock = enabled
+	_, errno = syscallConnControl(f.tl, func(fd uintptr) (int, experimentalsys.Errno) {
+		return 0, setNonblockSocket(fd, enabled)
+	})
+	return
+}
+
+// Shutdown implements the same method as documented on experimentalsys.Conn
+func (f *tcpConnFile) Shutdown(how int) experimentalsys.Errno {
+	// FIXME: can userland shutdown listeners?
+	var err error
+	switch how {
+	case socketapi.SHUT_RD:
+		err = f.tc.CloseRead()
+	case socketapi.SHUT_WR:
+		err = f.tc.CloseWrite()
+	case socketapi.SHUT_RDWR:
+		return f.close()
+	default:
+		return experimentalsys.EINVAL
+	}
+	return experimentalsys.UnwrapOSError(err)
+}
+
 // syscallConnControl extracts a syscall.RawConn from the given syscall.Conn and applies
 // the given fn to a file descriptor, returning an integer or a nonzero syscall.Errno on failure.
 //

internal/sysfs/sock_unix.go

@@ -1,4 +1,4 @@
-//go:build linux || darwin
+//go:build (linux || darwin) && !tinygo
 
 package sysfs
 

internal/sysfs/sock_unsupported.go

@@ -1,4 +1,4 @@
-//go:build !linux && !darwin && !windows
+//go:build (!linux && !darwin && !windows) || tinygo
 
 package sysfs
 
@@ -57,3 +57,25 @@ func recvfrom(fd uintptr, buf []byte, flags int32) (n int, errno sys.Errno) {
 func syscallConnControl(conn syscall.Conn, fn func(fd uintptr) (int, experimentalsys.Errno)) (n int, errno sys.Errno) {
 	return -1, sys.ENOTSUP
 }
+
+// Accept implements the same method as documented on socketapi.TCPSock
+func (f *tcpListenerFile) Accept() (socketapi.TCPConn, experimentalsys.Errno) {
+	return nil, experimentalsys.ENOSYS
+}
+
+// Shutdown implements the same method as documented on experimentalsys.Conn
+func (f *tcpConnFile) Shutdown(how int) experimentalsys.Errno {
+	// FIXME: can userland shutdown listeners?
+	var err error
+	switch how {
+	case socketapi.SHUT_RD:
+		err = f.tc.Close()
+	case socketapi.SHUT_WR:
+		err = f.tc.Close()
+	case socketapi.SHUT_RDWR:
+		return f.close()
+	default:
+		return experimentalsys.EINVAL
+	}
+	return experimentalsys.UnwrapOSError(err)
+}