runtime, syscall: use pointer types on wasmimport functions

Now that we support pointer types on wasmimport functions, use
them, instead of unsafe.Pointer. This removes unsafe conversions.
There is still one unsafe.Pointer argument left. It is actually a
*Stat_t, which is an exported type with an int field, which is not
allowed as a wasmimport field type. We probably cannot change it
at this point.

Updates #66984.

Change-Id: I445c70b356c3877a5604bee67d19d99a538c682e
Reviewed-on: https://go-review.googlesource.com/c/go/+/627059
Reviewed-by: Johan Brandhorst-Satzkorn <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: David Chase <[email protected]>

Author: cherrymui

src/go/build/deps_test.go

@@ -61,6 +61,7 @@ var depsRules = `
 	  internal/trace/traceviewer/format,
 	  log/internal,
 	  math/bits,
+	  structs,
 	  unicode,
 	  unicode/utf8,
 	  unicode/utf16;
@@ -78,7 +79,8 @@ var depsRules = `
 	internal/goexperiment,
 	internal/goos,
 	internal/profilerecord,
-	math/bits
+	math/bits,
+	structs
 	< internal/bytealg
 	< internal/stringslite
 	< internal/itoa

src/internal/syscall/unix/at_wasip1.go

@@ -27,11 +27,11 @@ func Readlinkat(dirfd int, path string, buf []byte) (int, error) {
 	var nwritten size
 	errno := path_readlink(
 		int32(dirfd),
-		unsafe.Pointer(unsafe.StringData(path)),
+		unsafe.StringData(path),
 		size(len(path)),
-		unsafe.Pointer(&buf[0]),
+		&buf[0],
 		size(len(buf)),
-		unsafe.Pointer(&nwritten))
+		&nwritten)
 	return int(nwritten), errnoErr(errno)
 
 }
@@ -42,22 +42,22 @@ type (
 
 //go:wasmimport wasi_snapshot_preview1 path_readlink
 //go:noescape
-func path_readlink(fd int32, path unsafe.Pointer, pathLen size, buf unsafe.Pointer, bufLen size, nwritten unsafe.Pointer) syscall.Errno
+func path_readlink(fd int32, path *byte, pathLen size, buf *byte, bufLen size, nwritten *size) syscall.Errno
 
 func Mkdirat(dirfd int, path string, mode uint32) error {
 	if path == "" {
 		return syscall.EINVAL
 	}
 	return errnoErr(path_create_directory(
 		int32(dirfd),
-		unsafe.Pointer(unsafe.StringData(path)),
+		unsafe.StringData(path),
 		size(len(path)),
 	))
 }
 
 //go:wasmimport wasi_snapshot_preview1 path_create_directory
 //go:noescape
-func path_create_directory(fd int32, path unsafe.Pointer, pathLen size) syscall.Errno
+func path_create_directory(fd int32, path *byte, pathLen size) syscall.Errno
 
 func errnoErr(errno syscall.Errno) error {
 	if errno == 0 {

src/runtime/netpoll_wasip1.go

@@ -209,7 +209,7 @@ func netpoll(delay int64) (gList, int32) {
 
 retry:
 	var nevents size
-	errno := poll_oneoff(unsafe.Pointer(&pollsubs[0]), unsafe.Pointer(&evts[0]), uint32(len(pollsubs)), unsafe.Pointer(&nevents))
+	errno := poll_oneoff(&pollsubs[0], &evts[0], uint32(len(pollsubs)), &nevents)
 	if errno != 0 {
 		if errno != _EINTR {
 			println("errno=", errno, " len(pollsubs)=", len(pollsubs))

src/runtime/os_wasip1.go

@@ -6,7 +6,10 @@
 
 package runtime
 
-import "unsafe"
+import (
+	"structs"
+	"unsafe"
+)
 
 // GOARCH=wasm currently has 64 bits pointers, but the WebAssembly host expects
 // pointers to be 32 bits so we use this type alias to represent pointers in
@@ -48,31 +51,31 @@ func exit(code int32)
 
 //go:wasmimport wasi_snapshot_preview1 args_get
 //go:noescape
-func args_get(argv, argvBuf unsafe.Pointer) errno
+func args_get(argv *uintptr32, argvBuf *byte) errno
 
 //go:wasmimport wasi_snapshot_preview1 args_sizes_get
 //go:noescape
-func args_sizes_get(argc, argvBufLen unsafe.Pointer) errno
+func args_sizes_get(argc, argvBufLen *size) errno
 
 //go:wasmimport wasi_snapshot_preview1 clock_time_get
 //go:noescape
-func clock_time_get(clock_id clockid, precision timestamp, time unsafe.Pointer) errno
+func clock_time_get(clock_id clockid, precision timestamp, time *timestamp) errno
 
 //go:wasmimport wasi_snapshot_preview1 environ_get
 //go:noescape
-func environ_get(environ, environBuf unsafe.Pointer) errno
+func environ_get(environ *uintptr32, environBuf *byte) errno
 
 //go:wasmimport wasi_snapshot_preview1 environ_sizes_get
 //go:noescape
-func environ_sizes_get(environCount, environBufLen unsafe.Pointer) errno
+func environ_sizes_get(environCount, environBufLen *size) errno
 
 //go:wasmimport wasi_snapshot_preview1 fd_write
 //go:noescape
-func fd_write(fd int32, iovs unsafe.Pointer, iovsLen size, nwritten unsafe.Pointer) errno
+func fd_write(fd int32, iovs unsafe.Pointer, iovsLen size, nwritten *size) errno
 
 //go:wasmimport wasi_snapshot_preview1 random_get
 //go:noescape
-func random_get(buf unsafe.Pointer, bufLen size) errno
+func random_get(buf *byte, bufLen size) errno
 
 type eventtype = uint8
 
@@ -99,13 +102,15 @@ type userdata = uint64
 // struct size because errno is declared as a 32 bits type, so we declare the
 // error field as a plain uint16.
 type event struct {
+	_           structs.HostLayout
 	userdata    userdata
 	error       uint16
 	typ         eventtype
 	fdReadwrite eventFdReadwrite
 }
 
 type eventFdReadwrite struct {
+	_      structs.HostLayout
 	nbytes filesize
 	flags  eventrwflags
 }
@@ -117,17 +122,20 @@ const (
 )
 
 type subscriptionClock struct {
+	_         structs.HostLayout
 	id        clockid
 	timeout   timestamp
 	precision timestamp
 	flags     subclockflags
 }
 
 type subscriptionFdReadwrite struct {
+	_  structs.HostLayout
 	fd int32
 }
 
 type subscription struct {
+	_        structs.HostLayout
 	userdata userdata
 	u        subscriptionUnion
 }
@@ -148,15 +156,15 @@ func (u *subscriptionUnion) subscriptionFdReadwrite() *subscriptionFdReadwrite {
 
 //go:wasmimport wasi_snapshot_preview1 poll_oneoff
 //go:noescape
-func poll_oneoff(in, out unsafe.Pointer, nsubscriptions size, nevents unsafe.Pointer) errno
+func poll_oneoff(in *subscription, out *event, nsubscriptions size, nevents *size) errno
 
 func write1(fd uintptr, p unsafe.Pointer, n int32) int32 {
 	iov := iovec{
 		buf:    uintptr32(uintptr(p)),
 		bufLen: size(n),
 	}
 	var nwritten size
-	if fd_write(int32(fd), unsafe.Pointer(&iov), 1, unsafe.Pointer(&nwritten)) != 0 {
+	if fd_write(int32(fd), unsafe.Pointer(&iov), 1, &nwritten) != 0 {
 		throw("fd_write failed")
 	}
 	return int32(nwritten)
@@ -175,13 +183,13 @@ func usleep(usec uint32) {
 	subscription.timeout = timestamp(usec) * 1e3
 	subscription.precision = 1e3
 
-	if poll_oneoff(unsafe.Pointer(&in), unsafe.Pointer(&out), 1, unsafe.Pointer(&nevents)) != 0 {
+	if poll_oneoff(&in, &out, 1, &nevents) != 0 {
 		throw("wasi_snapshot_preview1.poll_oneoff")
 	}
 }
 
 func readRandom(r []byte) int {
-	if random_get(unsafe.Pointer(&r[0]), size(len(r))) != 0 {
+	if random_get(&r[0], size(len(r))) != 0 {
 		return 0
 	}
 	return len(r)
@@ -191,15 +199,15 @@ func goenvs() {
 	// arguments
 	var argc size
 	var argvBufLen size
-	if args_sizes_get(unsafe.Pointer(&argc), unsafe.Pointer(&argvBufLen)) != 0 {
+	if args_sizes_get(&argc, &argvBufLen) != 0 {
 		throw("args_sizes_get failed")
 	}
 
 	argslice = make([]string, argc)
 	if argc > 0 {
 		argv := make([]uintptr32, argc)
 		argvBuf := make([]byte, argvBufLen)
-		if args_get(unsafe.Pointer(&argv[0]), unsafe.Pointer(&argvBuf[0])) != 0 {
+		if args_get(&argv[0], &argvBuf[0]) != 0 {
 			throw("args_get failed")
 		}
 
@@ -216,15 +224,15 @@ func goenvs() {
 	// environment
 	var environCount size
 	var environBufLen size
-	if environ_sizes_get(unsafe.Pointer(&environCount), unsafe.Pointer(&environBufLen)) != 0 {
+	if environ_sizes_get(&environCount, &environBufLen) != 0 {
 		throw("environ_sizes_get failed")
 	}
 
 	envs = make([]string, environCount)
 	if environCount > 0 {
 		environ := make([]uintptr32, environCount)
 		environBuf := make([]byte, environBufLen)
-		if environ_get(unsafe.Pointer(&environ[0]), unsafe.Pointer(&environBuf[0])) != 0 {
+		if environ_get(&environ[0], &environBuf[0]) != 0 {
 			throw("environ_get failed")
 		}
 
@@ -245,15 +253,15 @@ func walltime() (sec int64, nsec int32) {
 
 func walltime1() (sec int64, nsec int32) {
 	var time timestamp
-	if clock_time_get(clockRealtime, 0, unsafe.Pointer(&time)) != 0 {
+	if clock_time_get(clockRealtime, 0, &time) != 0 {
 		throw("clock_time_get failed")
 	}
 	return int64(time / 1000000000), int32(time % 1000000000)
 }
 
 func nanotime1() int64 {
 	var time timestamp
-	if clock_time_get(clockMonotonic, 0, unsafe.Pointer(&time)) != 0 {
+	if clock_time_get(clockMonotonic, 0, &time) != 0 {
 		throw("clock_time_get failed")
 	}
 	return int64(time)