[WasmFS] Consistent use of const char* in wasmfs API (#23775)

Author: sbc100

src/lib/libwasmfs.js

@@ -351,7 +351,7 @@ addToLibrary({
       return FS.handleError(withStackSave(() => __wasmfs_mount(stringToUTF8OnStack(mountpoint), backendPointer)));
     },
     unmount: (mountpoint) => (
-      FS.handleError(withStackSave(() => __wasmfs_unmount(stringToUTF8OnStack(mountpoint))))
+      FS.handleError(withStackSave(() => _wasmfs_unmount(stringToUTF8OnStack(mountpoint))))
     ),
     // TODO: lookup
     mknod: (path, mode, dev) => FS_mknod(path, mode, dev),

system/include/emscripten/wasmfs.h

@@ -17,7 +17,7 @@ extern "C" {
 typedef struct Backend* backend_t;
 
 // Obtains the backend_t of a specified path.
-backend_t wasmfs_get_backend_by_path(char* path __attribute__((nonnull)));
+backend_t wasmfs_get_backend_by_path(const char* path __attribute__((nonnull)));
 
 // Obtains the backend_t of a specified fd.
 backend_t wasmfs_get_backend_by_fd(int fd);
@@ -36,7 +36,7 @@ int wasmfs_create_directory(const char* path __attribute__((nonnull)), mode_t mo
 
 // Unmounts the directory (Which must be a valid mountpoint) at a specific path.
 // Returns 0 on success, or a negative value on error.
-int wasmfs_unmount(intptr_t path);
+int wasmfs_unmount(const char* path __attribute__((nonnull)));
 
 // Backend creation
 

system/lib/wasmfs/js_api.cpp

@@ -24,9 +24,8 @@ extern "C" {
 
 // TODO: Replace forward declarations with #include <emscripten/wasmfs.h> and
 // resolve wasmfs::backend_t namespace conflicts.
-__wasi_fd_t wasmfs_create_file(char* pathname, mode_t mode, backend_t backend);
-int wasmfs_create_directory(char* path, int mode, backend_t backend);
-int wasmfs_unmount(intptr_t path);
+__wasi_fd_t wasmfs_create_file(const char* pathname, mode_t mode, backend_t backend);
+int wasmfs_create_directory(const char* path, int mode, backend_t backend);
 
 // Copy the file specified by the pathname into JS.
 // Return a pointer to the JS buffer in HEAPU8.
@@ -298,10 +297,6 @@ int _wasmfs_mount(char* path, wasmfs::backend_t created_backend) {
   return wasmfs_create_directory(path, 0777, created_backend);
 }
 
-// WasmFS will always remove the mounted directory, regardless of if the
-// directory existed before.
-int _wasmfs_unmount(char* path) { return wasmfs_unmount((intptr_t)path); }
-
 // Helper method that identifies what a path is:
 //   ENOENT - if nothing exists there
 //   EISDIR - if it is a directory

system/lib/wasmfs/syscalls.cpp

@@ -867,8 +867,8 @@ int __syscall_rmdir(intptr_t path) {
 
 // wasmfs_unmount is similar to __syscall_unlinkat, but assumes AT_REMOVEDIR is
 // true and will only unlink mountpoints (Empty and nonempty).
-int wasmfs_unmount(intptr_t path) {
-  auto parsed = path::parseParent((char*)path, AT_FDCWD);
+int wasmfs_unmount(const char* path) {
+  auto parsed = path::parseParent(path, AT_FDCWD);
   if (auto err = parsed.getError()) {
     return err;
   }

tools/link.py

@@ -1260,8 +1260,8 @@ def phase_linker_setup(options, linker_args):  # noqa: C901, PLR0912, PLR0915
       settings.REQUIRED_EXPORTS += [
         'emscripten_builtin_memalign',
         'wasmfs_create_file',
+        'wasmfs_unmount',
         '_wasmfs_mount',
-        '_wasmfs_unmount',
         '_wasmfs_read_file',
         '_wasmfs_write_file',
         '_wasmfs_open',