[release-branch.go1.24] syscall: disable O_DIRECTORY on Windows for js/wasm

O_DIRECTORY is not available on all platforms, as described at

https://nodejs.org/docs/latest/api/fs.html#file-open-constants .

On Windows, only O_APPEND, O_CREAT, O_EXCL, O_RDONLY, O_RDWR,
O_TRUNC, O_WRONLY, and UV_FS_O_FILEMAP are available.

For #71758.
Fixes #71977.

Change-Id: Iacc890ba9a30dcd75eb746ec324fa0c3e368048e
GitHub-Last-Rev: a0160e8fc82583c4f903ae165fe9f204896cf56d
GitHub-Pull-Request: golang/go#71770
Reviewed-on: https://go-review.googlesource.com/c/go/+/650015
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Bypass: Dmitri Shuralyov <dmitshur@golang.org>
(cherry picked from commit ad8b33002bb5cb0c910694339e1cc6c75f781c5a)
Reviewed-on: https://go-review.googlesource.com/c/go/+/652835
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>

diff --git a/src/syscall/fs_js.go b/src/syscall/fs_js.go
index 111ce4f5c1e7c501f6aa22e18f07d231642f4cd4..7ef3cdee14a8b6dde35ae51b5bd0a3e8dd600eb7 100644 (file)
--- a/src/syscall/fs_js.go
+++ b/src/syscall/fs_js.go
@@ -23,15 +23,26 @@ var constants = jsFS.Get("constants")
 var uint8Array = js.Global().Get("Uint8Array")
 
 var (
-       nodeWRONLY    = constants.Get("O_WRONLY").Int()
-       nodeRDWR      = constants.Get("O_RDWR").Int()
-       nodeCREATE    = constants.Get("O_CREAT").Int()
-       nodeTRUNC     = constants.Get("O_TRUNC").Int()
-       nodeAPPEND    = constants.Get("O_APPEND").Int()
-       nodeEXCL      = constants.Get("O_EXCL").Int()
-       nodeDIRECTORY = constants.Get("O_DIRECTORY").Int()
+       nodeWRONLY = constants.Get("O_WRONLY").Int()
+       nodeRDWR   = constants.Get("O_RDWR").Int()
+       nodeCREATE = constants.Get("O_CREAT").Int()
+       nodeTRUNC  = constants.Get("O_TRUNC").Int()
+       nodeAPPEND = constants.Get("O_APPEND").Int()
+       nodeEXCL   = constants.Get("O_EXCL").Int()
+
+       // NodeJS on Windows does not support O_DIRECTORY, so we default
+       // to -1 and assign it in init if available.
+       // See https://nodejs.org/docs/latest/api/fs.html#file-open-constants.
+       nodeDIRECTORY = -1
 )
 
+func init() {
+       oDir := constants.Get("O_DIRECTORY")
+       if !oDir.IsUndefined() {
+               nodeDIRECTORY = oDir.Int()
+       }
+}
+
 type jsFile struct {
        path    string
        entries []string
@@ -85,7 +96,11 @@ func Open(path string, openmode int, perm uint32) (int, error) {
                return 0, errors.New("syscall.Open: O_SYNC is not supported by js/wasm")
        }
        if openmode&O_DIRECTORY != 0 {
-               flags |= nodeDIRECTORY
+               if nodeDIRECTORY != -1 {
+                       flags |= nodeDIRECTORY
+               } else {
+                       return 0, errors.New("syscall.Open: O_DIRECTORY is not supported on Windows")
+               }
        }
 
        jsFD, err := fsCall("open", path, flags, perm)