dylink: Make preload plugin dependency conditional on FILESYTEM (#19362)

The preload plugin system is part of the core filesystem code
in `library_fs_shared.py`.

Fixes: #19361

Author: sbc100

src/library_browser.js

@@ -12,9 +12,11 @@ var LibraryBrowser = {
     '$safeSetTimeout',
     '$warnOnce',
     'emscripten_set_main_loop_timing',
+#if FILESYSTEM || WASMFS
     '$preloadPlugins',
 #if MAIN_MODULE
     '$preloadedWasm',
+#endif
 #endif
   ],
   $Browser__postset: `
@@ -105,6 +107,7 @@ var LibraryBrowser = {
       if (Browser.initted) return;
       Browser.initted = true;
 
+#if FILESYSTEM || WASMFS
       // Support for plugins that can process preloaded files. You can add more of these to
       // your app by creating and appending to preloadPlugins.
       //
@@ -209,6 +212,7 @@ var LibraryBrowser = {
         }, 10000);
       };
       preloadPlugins.push(audioPlugin);
+#endif
 
       // Canvas event setup
 

src/library_dylink.js

@@ -10,6 +10,7 @@ var dlopenMissingError = "'To use dlopen, you need enable dynamic linking, see h
 
 var LibraryDylink = {
 #if RELOCATABLE
+#if FILESYSTEM || WASMFS
   $registerWasmPlugin__deps: ['$preloadPlugins'],
   $registerWasmPlugin: function() {
     // Use string keys here to avoid minification since the plugin consumer
@@ -43,6 +44,7 @@ var LibraryDylink = {
     registerWasmPlugin();
     `,
   $preloadedWasm: {},
+#endif // FILESYSTEM
 
   $isSymbolDefined: function(symName) {
     // Ignore 'stub' symbols that are auto-generated as part of the original
@@ -910,7 +912,11 @@ var LibraryDylink = {
   // Once a library becomes "global" or "nodelete", it cannot be removed or unloaded.
   $loadDynamicLibrary__deps: ['$LDSO', '$loadWebAssemblyModule',
                               '$isInternalSym', '$mergeLibSymbols', '$newDSO',
-                              '$asyncLoad', '$preloadedWasm'],
+                              '$asyncLoad',
+#if FILESYSTEM || WASMFS
+                              '$preloadedWasm',
+#endif
+  ],
   $loadDynamicLibrary__docs: `
     /**
      * @param {number=} handle
@@ -981,6 +987,7 @@ var LibraryDylink = {
 
     // libName -> exports
     function getExports() {
+#if FILESYSTEM || WASMFS
       // lookup preloaded cache first
       if (preloadedWasm[libName]) {
 #if DYLINK_DEBUG
@@ -989,6 +996,7 @@ var LibraryDylink = {
         var libModule = preloadedWasm[libName];
         return flags.loadAsync ? Promise.resolve(libModule) : libModule;
       }
+#endif
 
       // module not preloaded - load lib data and create new module from it
       if (flags.loadAsync) {

test/test_other.py

@@ -4994,7 +4994,7 @@ def test_libc_files_without_syscalls(self):
 }''')
     self.run_process([EMXX, 'src.cpp'])
 
-  def test_syscall_without_filesystem(self):
+  def test_syscall_no_filesystem(self):
     # a program which includes a non-trivial syscall, but disables the filesystem.
     create_file('src.c', r'''
 #include <sys/time.h>
@@ -5004,6 +5004,9 @@ def test_syscall_without_filesystem(self):
 }''')
     self.run_process([EMCC, 'src.c', '-sNO_FILESYSTEM'])
 
+  def test_dylink_no_filesystem(self):
+    self.run_process([EMCC, test_file('hello_world.c'), '-sMAIN_MODULE=2', '-sNO_FILESYSTEM'])
+
   def test_dashS(self):
     self.run_process([EMCC, test_file('hello_world.c'), '-S'])
     self.assertExists('hello_world.s')