Fix stat and chmod on windows under NODERAWFS (#23013)

Author: sbc100

src/library_nodefs.js

@@ -76,15 +76,14 @@ addToLibrary({
       return node;
     },
     getMode(path) {
-      var stat;
       return NODEFS.tryFSOperation(() => {
-        stat = fs.lstatSync(path);
+        var mode = fs.lstatSync(path).mode;
         if (NODEFS.isWindows) {
-          // Node.js on Windows never represents permission bit 'x', so
-          // propagate read bits to execute bits
-          stat.mode |= (stat.mode & {{{ cDefs.S_IRUSR | cDefs.S_IRGRP | cDefs.S_IROTH }}}) >> 2;
+          // Windows does not report the 'x' permission bit, so propagate read
+          // bits to execute bits.
+          mode |= (mode & {{{ cDefs.S_IRUGO }}}) >> 2;
         }
-        return stat.mode;
+        return mode;
       });
     },
     realPath(node) {
@@ -133,9 +132,9 @@ addToLibrary({
           if (!stat.blocks) {
             stat.blocks = (stat.size+stat.blksize-1)/stat.blksize|0;
           }
-          // Node.js on Windows never represents permission bit 'x', so
-          // propagate read bits to execute bits.
-          stat.mode |= (stat.mode & {{{ cDefs.S_IRUSR | cDefs.S_IRGRP | cDefs.S_IROTH }}}) >> 2;
+          // Windows does not report the 'x' permission bit, so propagate read
+          // bits to execute bits.
+          stat.mode |= (stat.mode & {{{ cDefs.S_IRUGO }}}) >> 2;
         }
         return {
           dev: stat.dev,
@@ -157,7 +156,13 @@ addToLibrary({
         var path = NODEFS.realPath(node);
         NODEFS.tryFSOperation(() => {
           if (attr.mode !== undefined) {
-            fs.chmodSync(path, attr.mode);
+            var mode = attr.mode;
+            if (NODEFS.isWindows) {
+              // Windows only supports S_IREAD / S_IWRITE (S_IRUSR / S_IWUSR)
+              // https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/chmod-wchmod
+              mode &= {{{ cDefs.S_IRUSR | cDefs.S_IWUSR }}};
+            }
+            fs.chmodSync(path, mode);
             // update the common node structure mode as well
             node.mode = attr.mode;
           }

src/library_noderawfs.js

@@ -70,9 +70,22 @@ addToLibrary({
     readdir(...args) { return ['.', '..'].concat(fs.readdirSync(...args)); },
     unlink(...args) { fs.unlinkSync(...args); },
     readlink(...args) { return fs.readlinkSync(...args); },
-    stat(...args) { return fs.statSync(...args); },
-    lstat(...args) { return fs.lstatSync(...args); },
+    stat(path, dontFollow) {
+      var stat = dontFollow ? fs.lstatSync(path) : fs.statSync(path);
+      if (NODEFS.isWindows) {
+        // Windows does not report the 'x' permission bit, so propagate read
+        // bits to execute bits.
+        stat.mode |= (stat.mode & {{{ cDefs.S_IRUGO }}}) >> 2;
+      }
+      return stat;
+    },
     chmod(path, mode, dontFollow) {
+      mode &= {{{ cDefs.S_IALLUGO }}};
+      if (NODEFS.isWindows) {
+        // Windows only supports S_IREAD / S_IWRITE (S_IRUSR / S_IWUSR)
+        // https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/chmod-wchmod
+        mode &= {{{ cDefs.S_IRUSR | cDefs.S_IWUSR }}};
+      }
       if (dontFollow && fs.lstatSync(path).isSymbolicLink()) {
         // Node (and indeed linux) does not support chmod on symlinks
         // https://nodejs.org/api/fs.html#fslchmodsyncpath-mode

src/struct_info.json

@@ -23,6 +23,12 @@
     {
         "file": "sys/stat.h",
         "defines": [
+            "S_IALLUGO",
+            "S_IWUSR",
+            "S_IWUGO",
+            "S_IRUGO",
+            "S_IRWXUGO",
+            "S_IXUGO",
             "S_IFDIR",
             "S_IFREG",
             "S_IFMT",
@@ -470,16 +476,6 @@
             "SEEK_SET"
         ]
     },
-    {
-        "file": "sys/stat.h",
-        "defines": [
-            "S_IALLUGO",
-            "S_IWUGO",
-            "S_IRUGO",
-            "S_IRWXUGO",
-            "S_IXUGO"
-        ]
-    },
     {
         "file": "sys/mman.h",
         "defines": [

src/struct_info_generated.json

@@ -447,6 +447,7 @@
         "S_IRWXUGO": 511,
         "S_ISVTX": 512,
         "S_IWUGO": 146,
+        "S_IWUSR": 128,
         "S_IXUGO": 73,
         "TCFLSH": 21515,
         "TCGETA": 21509,

src/struct_info_generated_wasm64.json

@@ -447,6 +447,7 @@
         "S_IRWXUGO": 511,
         "S_ISVTX": 512,
         "S_IWUGO": 146,
+        "S_IWUSR": 128,
         "S_IXUGO": 73,
         "TCFLSH": 21515,
         "TCGETA": 21509,

test/test_core.py

@@ -5911,25 +5911,31 @@ def test_sigaction_default(self, signal, exit_code, assert_identical):
       assert_returncode=exit_code
     )
 
-  @no_windows('https://github.com/emscripten-core/emscripten/issues/8882')
   @requires_node
+  @crossplatform
   @parameterized({
     '': (['-DMEMFS'],),
     'nodefs': (['-DNODEFS', '-lnodefs.js'],),
     'noderawfs': (['-DNODERAWFS', '-sNODERAWFS'],)
   })
   def test_unistd_access(self, args):
     self.emcc_args += args
+    nodefs = '-DNODEFS' in args or '-DNODERAWFS' in args
     if self.get_setting('WASMFS'):
-      if '-DNODEFS' in args or '-DNODERAWFS' in args:
+      if nodefs:
         self.skipTest('NODEFS in WasmFS')
       self.emcc_args += ['-sFORCE_FILESYSTEM']
-
-    # Node.js fs.chmod is nearly no-op on Windows
-    if '-DNODERAWFS' in args and WINDOWS:
-      self.skipTest('NODERAWFS on windows')
-
-    self.do_run_in_out_file_test('unistd/access.c')
+    # On windows we have slighly different output because we the same
+    # level of permissions are not available. For example, on windows
+    # its not possible have a file that is not readable, but writable.
+    # We also report all files as executable since there is no x bit
+    # recorded there.
+    # See https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/chmod-wchmod?view=msvc-170#remarks
+    if WINDOWS and '-DNODERAWFS' in args:
+      out_suffix = '.win'
+    else:
+      out_suffix = ''
+    self.do_run_in_out_file_test('unistd/access.c', out_suffix=out_suffix)
 
   def test_unistd_curdir(self):
     if self.get_setting('WASMFS'):

test/unistd/access.c

@@ -10,6 +10,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
@@ -31,18 +32,10 @@ int main() {
   char* files[] = {"readable", "writeable",
                    "allaccess", "forbidden", "nonexistent", ""};
   for (int i = 0; i < sizeof files / sizeof files[0]; i++) {
-    printf("F_OK(%s): %d\n", files[i], access(files[i], F_OK));
-    printf("errno: %d\n", errno);
-    errno = 0;
-    printf("R_OK(%s): %d\n", files[i], access(files[i], R_OK));
-    printf("errno: %d\n", errno);
-    errno = 0;
-    printf("X_OK(%s): %d\n", files[i], access(files[i], X_OK));
-    printf("errno: %d\n", errno);
-    errno = 0;
-    printf("W_OK(%s): %d\n", files[i], access(files[i], W_OK));
-    printf("errno: %d\n", errno);
-    errno = 0;
+    printf("F_OK('%s'): %s\n", files[i], access(files[i], F_OK) < 0 ? strerror(errno) : "OK");
+    printf("R_OK('%s'): %s\n", files[i], access(files[i], R_OK) < 0 ? strerror(errno) : "OK");
+    printf("X_OK('%s'): %s\n", files[i], access(files[i], X_OK) < 0 ? strerror(errno) : "OK");
+    printf("W_OK('%s'): %s\n", files[i], access(files[i], W_OK) < 0 ? strerror(errno) : "OK");
     printf("\n");
   }
 
@@ -51,25 +44,20 @@ int main() {
   int rename_ret = rename("filetorename", "renamedfile");
   assert(rename_ret == 0);
 
-  errno = 0;
-  printf("F_OK(%s): %d\n", "filetorename", access("filetorename", F_OK));
-  printf("errno: %d\n", errno);
-  errno = 0;
-  printf("F_OK(%s): %d\n", "renamedfile", access("renamedfile", F_OK));
-  printf("errno: %d\n", errno);
+  printf("F_OK('%s'): %d\n", "filetorename", access("filetorename", F_OK));
+  printf("F_OK('%s'): %d\n", "renamedfile", access("renamedfile", F_OK));
 
   // Same againt with faccessat
-  errno = 0;
-  printf("F_OK(%s): %d\n", "filetorename", faccessat(AT_FDCWD, "filetorename", F_OK, 0));
-  printf("errno: %d\n", errno);
-  errno = 0;
-  printf("F_OK(%s): %d\n", "renamedfile", faccessat(AT_FDCWD, "renamedfile", F_OK, 0));
-  printf("errno: %d\n", errno);
-
-  chmod("fchmodtest", 0666);
+  printf("F_OK('%s'): %d\n", "filetorename", faccessat(AT_FDCWD, "filetorename", F_OK, 0));
+  printf("F_OK('%s'): %d\n", "renamedfile", faccessat(AT_FDCWD, "renamedfile", F_OK, 0));
+
+  chmod("fchmodtest", S_IRUGO | S_IWUGO);
   struct stat fileStats;
   stat("fchmodtest", &fileStats);
-  assert((fileStats.st_mode & 0777) == 0666);
+  int mode = fileStats.st_mode & 0777;
+  // Allow S_IXUGO in addtion to S_IWUGO because on windows
+  // we always report the execute bit.
+  assert(mode == (S_IRUGO | S_IWUGO) || mode == (S_IRUGO | S_IWUGO | S_IXUGO));
 
   EM_ASM(
     var fchmodstream = FS.open("fchmodtest", "r");
@@ -92,7 +80,8 @@ int main() {
   assert((symlinkStats.st_mode & 0777) == 0777);
 
   stat("writeable", &fileStats);
-  assert((fileStats.st_mode & 0777) == 0222);
+  mode = fileStats.st_mode & 0777;
+  assert(mode == S_IWUGO || mode == (S_IWUGO | S_IXUGO));
 #endif
 
   EM_ASM(

test/unistd/access.out

@@ -1,62 +1,34 @@
-F_OK(readable): 0
-errno: 0
-R_OK(readable): 0
-errno: 0
-X_OK(readable): -1
-errno: 2
-W_OK(readable): -1
-errno: 2
+F_OK('readable'): OK
+R_OK('readable'): OK
+X_OK('readable'): Permission denied
+W_OK('readable'): Permission denied
 
-F_OK(writeable): 0
-errno: 0
-R_OK(writeable): -1
-errno: 2
-X_OK(writeable): -1
-errno: 2
-W_OK(writeable): 0
-errno: 0
+F_OK('writeable'): OK
+R_OK('writeable'): Permission denied
+X_OK('writeable'): Permission denied
+W_OK('writeable'): OK
 
-F_OK(allaccess): 0
-errno: 0
-R_OK(allaccess): 0
-errno: 0
-X_OK(allaccess): 0
-errno: 0
-W_OK(allaccess): 0
-errno: 0
+F_OK('allaccess'): OK
+R_OK('allaccess'): OK
+X_OK('allaccess'): OK
+W_OK('allaccess'): OK
 
-F_OK(forbidden): 0
-errno: 0
-R_OK(forbidden): -1
-errno: 2
-X_OK(forbidden): -1
-errno: 2
-W_OK(forbidden): -1
-errno: 2
+F_OK('forbidden'): OK
+R_OK('forbidden'): Permission denied
+X_OK('forbidden'): Permission denied
+W_OK('forbidden'): Permission denied
 
-F_OK(nonexistent): -1
-errno: 44
-R_OK(nonexistent): -1
-errno: 44
-X_OK(nonexistent): -1
-errno: 44
-W_OK(nonexistent): -1
-errno: 44
+F_OK('nonexistent'): No such file or directory
+R_OK('nonexistent'): No such file or directory
+X_OK('nonexistent'): No such file or directory
+W_OK('nonexistent'): No such file or directory
 
-F_OK(): -1
-errno: 44
-R_OK(): -1
-errno: 44
-X_OK(): -1
-errno: 44
-W_OK(): -1
-errno: 44
+F_OK(''): No such file or directory
+R_OK(''): No such file or directory
+X_OK(''): No such file or directory
+W_OK(''): No such file or directory
 
-F_OK(filetorename): -1
-errno: 44
-F_OK(renamedfile): 0
-errno: 0
-F_OK(filetorename): -1
-errno: 44
-F_OK(renamedfile): 0
-errno: 0
+F_OK('filetorename'): -1
+F_OK('renamedfile'): 0
+F_OK('filetorename'): -1
+F_OK('renamedfile'): 0

test/unistd/access.win.out

@@ -0,0 +1,34 @@
+F_OK('readable'): OK
+R_OK('readable'): OK
+X_OK('readable'): OK
+W_OK('readable'): Permission denied
+
+F_OK('writeable'): OK
+R_OK('writeable'): OK
+X_OK('writeable'): OK
+W_OK('writeable'): OK
+
+F_OK('allaccess'): OK
+R_OK('allaccess'): OK
+X_OK('allaccess'): OK
+W_OK('allaccess'): OK
+
+F_OK('forbidden'): OK
+R_OK('forbidden'): OK
+X_OK('forbidden'): OK
+W_OK('forbidden'): Permission denied
+
+F_OK('nonexistent'): No such file or directory
+R_OK('nonexistent'): No such file or directory
+X_OK('nonexistent'): No such file or directory
+W_OK('nonexistent'): No such file or directory
+
+F_OK(''): No such file or directory
+R_OK(''): No such file or directory
+X_OK(''): No such file or directory
+W_OK(''): No such file or directory
+
+F_OK('filetorename'): -1
+F_OK('renamedfile'): 0
+F_OK('filetorename'): -1
+F_OK('renamedfile'): 0