Add CWD handling to standalone WASI mode, and some related syscalls

.circleci/config.yml

@@ -494,7 +494,7 @@ jobs:
           name: get wasmtime
           command: |
             # use a pinned version due to https://github.com/bytecodealliance/wasmtime/issues/714
-            export VERSION=v0.33.0
+            export VERSION=v32.0.0
             wget https://github.com/bytecodealliance/wasmtime/releases/download/$VERSION/wasmtime-$VERSION-x86_64-linux.tar.xz
             tar -xf wasmtime-$VERSION-x86_64-linux.tar.xz
             cp wasmtime-$VERSION-x86_64-linux/wasmtime ~/vms

LICENSE

@@ -100,3 +100,31 @@ The third_party/ subdirectory contains code with other licenses. None of it is
 used by default, but certain options use it (e.g., the optional closure compiler
 flag will run closure compiler from third_party/).
 
+Files in system/lib/standalone/ contain code derived from wasi-libc, in
+accordance with the terms of the MIT license. wasi-libc's license follows:
+
+    """
+        Permission is hereby granted, free of charge, to any
+        person obtaining a copy of this software and associated
+        documentation files (the "Software"), to deal in the
+        Software without restriction, including without
+        limitation the rights to use, copy, modify, merge,
+        publish, distribute, sublicense, and/or sell copies of
+        the Software, and to permit persons to whom the Software
+        is furnished to do so, subject to the following
+        conditions:
+
+        The above copyright notice and this permission notice
+        shall be included in all copies or substantial portions
+        of the Software.
+
+        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+        ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+        TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+        PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+        SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+        CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+        OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+        IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+        DEALINGS IN THE SOFTWARE.
+    """

src/lib/libsigs.js

@@ -969,6 +969,7 @@ sigs = {
   fd_pread__sig: 'iippjp',
   fd_pwrite__sig: 'iippjp',
   fd_read__sig: 'iippp',
+  fd_readdir__sig: 'iippjp',
   fd_seek__sig: 'iijip',
   fd_sync__sig: 'ii',
   fd_write__sig: 'iippp',
@@ -1536,6 +1537,9 @@ sigs = {
   lineColor__sig: 'ipiiiii',
   lineRGBA__sig: 'ipiiiiiiii',
   llvm_eh_typeid_for__sig: 'vp',
+  path_create_directory__sig: 'iipp',
+  path_filestat_get__sig: 'iiippp',
+  path_symlink__sig: 'ippipp',
   pixelRGBA__sig: 'ipiiiiii',
   proc_exit__sig: 'vi',
   random_get__sig: 'ipp',

src/lib/libwasi.js

@@ -612,6 +612,26 @@ var WasiLibrary = {
     randomFill(HEAPU8.subarray(buffer, buffer + size));
     return 0;
   },
+
+  path_filestat_get__nothrow: true,
+  path_filestat_get: (fd, flags, path, path_len, buf) => {
+    return {{{ cDefs.ENOSYS }}};
+  },
+
+  path_create_directory__nothrow: true,
+  path_create_directory: (fd, path, path_len) => {
+    return {{{ cDefs.ENOSYS }}};
+  },
+
+  path_symlink__nothrow: true,
+  path_symlink: (old_path, old_path_len, fd, new_path, new_path_len) => {
+    return {{{ cDefs.ENOSYS }}};
+  },
+
+  fd_readdir__nothrow: true,
+  fd_readdir: (fd, buf, buf_len, cookie, bufused) => {
+    return {{{ cDefs.ENOSYS }}};
+  },
 };
 
 for (var x in WasiLibrary) {

system/lib/libc/musl/src/dirent/seekdir.c

@@ -7,6 +7,11 @@ void seekdir(DIR *dir, long off)
 {
 	LOCK(dir->lock);
 	dir->tell = lseek(dir->fd, off, SEEK_SET);
+#if defined(__EMSCRIPTEN__)
+	// The above relies on `lseek` to work on a directory fd, which is not
+	// guaranteed on WASI. Just set `off` again if the above failed.
+	dir->tell = off;
+#endif
 	dir->buf_pos = dir->buf_end = 0;
 	UNLOCK(dir->lock);
 }