stub truncate for wasip2

Signed-off-by: leongross <[email protected]>

Author: leongross

src/os/file_unix.go

@@ -128,7 +128,6 @@ func Readlink(name string) (string, error) {
 // Truncate changes the size of the file.
 // It does not change the I/O offset.
 // If there is an error, it will be of type *PathError.
-
 // Alternatively just use 'raw' syscall by file name
 func (f *File) Truncate(size int64) (err error) {
 	if f.handle == nil {

src/os/truncate_test.go

@@ -14,8 +14,10 @@ import (
 )
 
 func TestTruncate(t *testing.T) {
-	if runtime.GOOS == "windows" {
-		t.Skip()
+	// Truncate is not supported on Windows or wasi at the moment
+	if runtime.GOOS == "windows" || runtime.GOOS == "wasip1" || runtime.GOOS == "wasip2" {
+		t.Logf("skipping test on %s", runtime.GOOS)
+		return
 	}
 
 	tmpDir := t.TempDir()
@@ -25,6 +27,7 @@ func TestTruncate(t *testing.T) {
 	if err != nil {
 		t.Fatalf("create %q: got %v, want nil", file, err)
 	}
+	defer fd.Close()
 
 	// truncate up to 0x100
 	if err := fd.Truncate(0x100); err != nil {

src/syscall/libc_wasip2.go

@@ -432,7 +432,6 @@ func chmod(pathname *byte, mode uint32) int32 {
 //
 //export mkdir
 func mkdir(pathname *byte, mode uint32) int32 {
-
 	path := goString(pathname)
 	dir, relPath := findPreopenForPath(path)
 	if dir.d == cm.ResourceNone {
@@ -773,7 +772,6 @@ var libcCWD wasiDir
 var wasiPreopens map[string]types.Descriptor
 
 func populatePreopens() {
-
 	var cwd string
 
 	// find CWD
@@ -1354,3 +1352,11 @@ func getcwd(buf *byte, size uint) *byte {
 	copy(s, cwd)
 	return buf
 }
+
+// int truncate(const char *path, off_t length);
+//
+//export truncate
+func truncate(path *byte, length int64) int32 {
+	libcErrno = ENOSYS
+	return -1
+}

src/syscall/syscall_libc.go

@@ -465,6 +465,3 @@ func libc_execve(filename *byte, argv **byte, envp **byte) int
 //
 //export truncate
 func libc_truncate(path *byte, length int64) int32
-
-//go:extern environ
-var libc_environ *unsafe.Pointer