Finalize EMCC_STRICT mode for linking to libraries. Improve browser suite to pass in EMCC_STRICT mode.

Author: juj

emcc.py

@@ -955,12 +955,18 @@ def detect_fixed_language_mode(args):
             'm': '',
             'openal': 'library_openal.js',
             'pthread': '',
+            'X11': 'library_xlib.js',
             'SDL': 'library_sdl.js',
-            'stdc++': ''
+            'stdc++': '',
+            'uuid': 'library_uuid.js'
           }
           if lib in js_system_libraries:
             if len(js_system_libraries[lib]) > 0:
               system_js_libraries += [js_system_libraries[lib]]
+
+              # TODO: This is unintentional due to historical reasons. Improve EGL to use HTML5 API to avoid depending on GLUT.
+              if lib == 'EGL': system_js_libraries += ['library_glut.js']
+
           elif lib.endswith('.js') and os.path.isfile(shared.path_from_root('src', 'library_' + lib)):
             system_js_libraries += ['library_' + lib]
           else:
@@ -972,6 +978,12 @@ def detect_fixed_language_mode(args):
             else:
               logging.warning('emcc: cannot find library "%s"', lib)
 
+      # Certain linker flags imply some link libraries to be pulled in by default.
+      if 'EMTERPRETIFY_ASYNC=1' in settings_changes: system_js_libraries += ['library_async.js']
+      if 'ASYNCIFY=1' in settings_changes: system_js_libraries += ['library_async.js']
+      if 'LZ4=1' in settings_changes: system_js_libraries += ['library_lz4.js']
+      if 'USE_SDL=1' in settings_changes: system_js_libraries += ['library_sdl.js']
+      if 'USE_SDL=2' in settings_changes: system_js_libraries += ['library_egl.js', 'library_glut.js', 'library_gl.js']
       settings_changes.append('SYSTEM_JS_LIBRARIES="' + ','.join(system_js_libraries) + '"')
 
       # If not compiling to JS, then we are compiling to an intermediate bitcode objects or library, so

src/library_fs.js

@@ -1,5 +1,15 @@
 mergeInto(LibraryManager.library, {
-  $FS__deps: ['$ERRNO_CODES', '$ERRNO_MESSAGES', '__setErrNo', '$PATH', '$TTY', '$MEMFS', '$IDBFS', '$NODEFS', '$WORKERFS', 'stdin', 'stdout', 'stderr'],
+  $FS__deps: ['$ERRNO_CODES', '$ERRNO_MESSAGES', '__setErrNo', '$PATH', '$TTY', '$MEMFS',
+#if __EMSCRIPTEN_HAS_idbfs_js__
+  '$IDBFS',
+#endif
+#if __EMSCRIPTEN_HAS_nodefs_js__
+   '$NODEFS',
+#endif
+#if __EMSCRIPTEN_HAS_workerfs_js__
+   '$WORKERFS',
+#endif
+   'stdin', 'stdout', 'stderr'],
   $FS__postset: 'FS.staticInit();' +
                 '__ATINIT__.unshift(function() { if (!Module["noFSInit"] && !FS.init.initialized) FS.init() });' +
                 '__ATMAIN__.push(function() { FS.ignorePermissions = false });' +
@@ -1379,9 +1389,15 @@ mergeInto(LibraryManager.library, {
 
       FS.filesystems = {
         'MEMFS': MEMFS,
+#if __EMSCRIPTEN_HAS_idbfs_js__
         'IDBFS': IDBFS,
+#endif
+#if __EMSCRIPTEN_HAS_nodefs_js__
         'NODEFS': NODEFS,
+#endif
+#if __EMSCRIPTEN_HAS_workerfs_js__
         'WORKERFS': WORKERFS,
+#endif
       };
     },
     init: function(input, output, error) {

src/modules.js

@@ -102,6 +102,7 @@ var LibraryManager = {
       'library_browser.js',
       'library_formatString.js',
       'library_path.js',
+      'library_signals.js',
       'library_syscall.js',
       'library_html5.js'
     ];
@@ -138,7 +139,6 @@ var LibraryManager = {
         'library_glfw.js',
         'library_uuid.js',
         'library_glew.js',
-        'library_signals.js',
         'library_idbstore.js',
         'library_async.js',
         'library_vr.js'
@@ -148,6 +148,11 @@ var LibraryManager = {
     // If there are any explicitly specified system JS libraries to link to, add those to link.
     if (SYSTEM_JS_LIBRARIES) {
       SYSTEM_JS_LIBRARIES = SYSTEM_JS_LIBRARIES.split(',');
+      // For each system JS library library_xxx.js, add a preprocessor token __EMSCRIPTEN_HAS_xxx_js__ so that code can conditionally dead code eliminate out
+      // if a particular feature is not being linked in.
+      for (var i = 0; i < SYSTEM_JS_LIBRARIES.length; ++i) {
+        global['__EMSCRIPTEN_HAS_' + SYSTEM_JS_LIBRARIES[i].replace('.', '_').replace('library_', '') + '__'] = 1
+      }
       libraries = libraries.concat(SYSTEM_JS_LIBRARIES);
     }