internal: add tags and stubs so wazero can be compiled for MCU targets (#2166)

Signed-off-by: deadprogram <ron@hybridgroup.com>

.github/workflows/commit.yaml

@@ -167,6 +167,7 @@ jobs:
         with:
           tinygo-version: "0.31.2"
       - run: tinygo build ./cmd/wazero
+      - run: tinygo build -size short -target pico -stack-size=8kb ./cmd/wazero
 
   bench:
     name: Benchmark

internal/sock/sock_supported.go

@@ -1,4 +1,4 @@
-//go:build !plan9 && !js
+//go:build !plan9 && !js && !tinygo
 
 package sock
 

internal/sock/sock_unsupported.go

@@ -1,4 +1,4 @@
-//go:build plan9 || js
+//go:build plan9 || js || tinygo
 
 package sock
 

internal/sysfs/datasync_linux.go

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

internal/sysfs/datasync_tinygo.go

@@ -0,0 +1,13 @@
+//go:build tinygo
+
+package sysfs
+
+import (
+	"os"
+
+	"github.com/tetratelabs/wazero/experimental/sys"
+)
+
+func datasync(f *os.File) sys.Errno {
+	return sys.ENOSYS
+}

internal/sysfs/dirfs.go

@@ -63,18 +63,6 @@ func (d *dirFS) Mkdir(path string, perm fs.FileMode) (errno experimentalsys.Errn
 	return
 }
 
-// Chmod implements the same method as documented on sys.FS
-func (d *dirFS) Chmod(path string, perm fs.FileMode) experimentalsys.Errno {
-	err := os.Chmod(d.join(path), perm)
-	return experimentalsys.UnwrapOSError(err)
-}
-
-// Rename implements the same method as documented on sys.FS
-func (d *dirFS) Rename(from, to string) experimentalsys.Errno {
-	from, to = d.join(from), d.join(to)
-	return rename(from, to)
-}
-
 // Readlink implements the same method as documented on sys.FS
 func (d *dirFS) Readlink(path string) (string, experimentalsys.Errno) {
 	// Note: do not use syscall.Readlink as that causes race on Windows.
@@ -91,20 +79,6 @@ func (d *dirFS) Rmdir(path string) experimentalsys.Errno {
 	return rmdir(d.join(path))
 }
 
-// Unlink implements the same method as documented on sys.FS
-func (d *dirFS) Unlink(path string) (err experimentalsys.Errno) {
-	return unlink(d.join(path))
-}
-
-// Symlink implements the same method as documented on sys.FS
-func (d *dirFS) Symlink(oldName, link string) experimentalsys.Errno {
-	// Note: do not resolve `oldName` relative to this dirFS. The link result is always resolved
-	// when dereference the `link` on its usage (e.g. readlink, read, etc).
-	// https://github.com/bytecodealliance/cap-std/blob/v1.0.4/cap-std/src/fs/dir.rs#L404-L409
-	err := os.Symlink(oldName, d.join(link))
-	return experimentalsys.UnwrapOSError(err)
-}
-
 // Utimens implements the same method as documented on sys.FS
 func (d *dirFS) Utimens(path string, atim, mtim int64) experimentalsys.Errno {
 	return utimens(d.join(path), atim, mtim)

internal/sysfs/dirfs_link_supported.go

@@ -1,15 +0,0 @@
-//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

@@ -1,12 +0,0 @@
-//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/dirfs_supported.go

@@ -0,0 +1,42 @@
+//go:build !tinygo
+
+package sysfs
+
+import (
+	"io/fs"
+	"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)
+}
+
+// Unlink implements the same method as documented on sys.FS
+func (d *dirFS) Unlink(path string) (err experimentalsys.Errno) {
+	return unlink(d.join(path))
+}
+
+// Rename implements the same method as documented on sys.FS
+func (d *dirFS) Rename(from, to string) experimentalsys.Errno {
+	from, to = d.join(from), d.join(to)
+	return rename(from, to)
+}
+
+// Chmod implements the same method as documented on sys.FS
+func (d *dirFS) Chmod(path string, perm fs.FileMode) experimentalsys.Errno {
+	err := os.Chmod(d.join(path), perm)
+	return experimentalsys.UnwrapOSError(err)
+}
+
+// Symlink implements the same method as documented on sys.FS
+func (d *dirFS) Symlink(oldName, link string) experimentalsys.Errno {
+	// Note: do not resolve `oldName` relative to this dirFS. The link result is always resolved
+	// when dereference the `link` on its usage (e.g. readlink, read, etc).
+	// https://github.com/bytecodealliance/cap-std/blob/v1.0.4/cap-std/src/fs/dir.rs#L404-L409
+	err := os.Symlink(oldName, d.join(link))
+	return experimentalsys.UnwrapOSError(err)
+}

internal/sysfs/dirfs_unsupported.go

@@ -0,0 +1,34 @@
+//go:build tinygo
+
+package sysfs
+
+import (
+	"io/fs"
+
+	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
+}
+
+// Unlink implements the same method as documented on sys.FS
+func (d *dirFS) Unlink(path string) (err experimentalsys.Errno) {
+	return experimentalsys.ENOSYS
+}
+
+// Rename implements the same method as documented on sys.FS
+func (d *dirFS) Rename(from, to string) experimentalsys.Errno {
+	return experimentalsys.ENOSYS
+}
+
+// Chmod implements the same method as documented on sys.FS
+func (d *dirFS) Chmod(path string, perm fs.FileMode) experimentalsys.Errno {
+	return experimentalsys.ENOSYS
+}
+
+// Symlink implements the same method as documented on sys.FS
+func (d *dirFS) Symlink(oldName, link string) experimentalsys.Errno {
+	return experimentalsys.ENOSYS
+}

internal/sysfs/file_unix.go

@@ -1,4 +1,4 @@
-//go:build unix
+//go:build unix && !tinygo
 
 package sysfs
 

internal/sysfs/file_unsupported.go

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

internal/sysfs/futimens.go

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

internal/sysfs/futimens_linux.go

@@ -1,3 +1,5 @@
+//go:build !tinygo
+
 package sysfs
 
 import (

internal/sysfs/futimens_unsupported.go

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

internal/sysfs/ino.go

@@ -1,4 +1,4 @@
-//go:build !windows && !plan9
+//go:build !windows && !plan9 && !tinygo
 
 package sysfs
 

internal/sysfs/ino_tinygo.go

@@ -0,0 +1,14 @@
+//go:build tinygo
+
+package sysfs
+
+import (
+	"io/fs"
+
+	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
+	"github.com/tetratelabs/wazero/sys"
+)
+
+func inoFromFileInfo(_ string, info fs.FileInfo) (sys.Inode, experimentalsys.Errno) {
+	return 0, experimentalsys.ENOTSUP
+}

internal/sysfs/nonblock_unix.go

@@ -1,4 +1,4 @@
-//go:build !windows && !plan9
+//go:build !windows && !plan9 && !tinygo
 
 package sysfs
 

internal/sysfs/nonblock_unsupported.go

@@ -1,3 +1,5 @@
+//go:build plan9 || tinygo
+
 package sysfs
 
 import "github.com/tetratelabs/wazero/experimental/sys"

internal/sysfs/open_file_linux.go

@@ -1,3 +1,5 @@
+//go:build !tinygo
+
 package sysfs
 
 import (

internal/sysfs/open_file_notwindows.go

@@ -1,4 +1,4 @@
-//go:build !windows
+//go:build !windows && !tinygo
 
 package sysfs
 

internal/sysfs/open_file_tinygo.go

@@ -0,0 +1,25 @@
+//go:build tinygo
+
+package sysfs
+
+import (
+	"io/fs"
+	"os"
+
+	"github.com/tetratelabs/wazero/experimental/sys"
+)
+
+const supportedSyscallOflag = sys.Oflag(0)
+
+func withSyscallOflag(oflag sys.Oflag, flag int) int {
+	// O_DIRECTORY not defined
+	// O_DSYNC not defined
+	// O_NOFOLLOW not defined
+	// O_NONBLOCK not defined
+	// O_RSYNC not defined
+	return flag
+}
+
+func openFile(path string, oflag sys.Oflag, perm fs.FileMode) (*os.File, sys.Errno) {
+	return nil, sys.ENOSYS
+}

internal/sysfs/poll.go

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

internal/sysfs/poll_linux.go

@@ -1,3 +1,5 @@
+//go:build !tinygo
+
 package sysfs
 
 import (

internal/sysfs/poll_unsupported.go

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

internal/sysfs/rename.go

@@ -1,4 +1,4 @@
-//go:build !windows && !plan9
+//go:build !windows && !plan9 && !tinygo
 
 package sysfs
 

internal/sysfs/unlink.go

@@ -1,4 +1,4 @@
-//go:build !windows && !plan9
+//go:build !windows && !plan9 && !tinygo
 
 package sysfs