Use nullish coalescing in more places in the JS library. NFC (#22601)

src/library.js

@@ -1551,8 +1551,7 @@ addToLibrary({
     var ret = getCompilerSetting(name);
     if (typeof ret == 'number' || typeof ret == 'boolean') return ret;
 
-    if (!_emscripten_get_compiler_setting.cache) _emscripten_get_compiler_setting.cache = {};
-    var cache = _emscripten_get_compiler_setting.cache;
+    var cache = _emscripten_get_compiler_setting.cache ??= {};
     var fullret = cache[name];
     if (fullret) return fullret;
     return cache[name] = stringToNewUTF8(ret);

src/library_fs.js

@@ -66,7 +66,9 @@ FS.staticInit();
     genericErrors: {},
     filesystems: null,
     syncFSRequests: 0, // we warn if there are multiple in flight at once
-
+#if expectToReceiveOnModule('logReadFiles')
+    readFiles: {},
+#endif
 #if ASSERTIONS
     ErrnoError: class extends Error {
 #else
@@ -1100,15 +1102,16 @@ FS.staticInit();
       if (stream.stream_ops.open) {
         stream.stream_ops.open(stream);
       }
+#if expectToReceiveOnModule('logReadFiles')
       if (Module['logReadFiles'] && !(flags & {{{ cDefs.O_WRONLY}}})) {
-        if (!FS.readFiles) FS.readFiles = {};
         if (!(path in FS.readFiles)) {
           FS.readFiles[path] = 1;
 #if FS_DEBUG
           dbg(`FS.trackingDelegate error on read file: ${path}`);
 #endif
         }
       }
+#endif
 #if FS_DEBUG
       if (FS.trackingDelegate['onOpenFile']) {
         FS.trackingDelegate['onOpenFile'](path, trackingFlags);
@@ -1588,7 +1591,7 @@ FS.staticInit();
     createDevice(parent, name, input, output) {
       var path = PATH.join2(typeof parent == 'string' ? parent : FS.getPath(parent), name);
       var mode = FS_getMode(!!input, !!output);
-      if (!FS.createDevice.major) FS.createDevice.major = 64;
+      FS.createDevice.major ??= 64;
       var dev = FS.makedev(FS.createDevice.major++, 0);
       // Create a fake device that a set of stream ops to emulate
       // the old behavior.

src/library_html5.js

@@ -12,22 +12,27 @@ var LibraryHTML5 = {
   ],
   $JSEvents: {
 
-/* We do not depend on the exact initial values of falsey member fields - these
-   fields can be populated on-demand to save code size.
-   (but still documented here to keep track of what is supposed to be present)
-
+#if USE_CLOSURE_COMPILER
     // pointers to structs malloc()ed to Emscripten HEAP for JS->C interop.
+    batteryEvent: 0,
+    gamepadEvent: 0,
     keyEvent: 0,
     mouseEvent: 0,
     wheelEvent: 0,
     uiEvent: 0,
     focusEvent: 0,
     deviceOrientationEvent: 0,
+    orientationChangeEvent: 0,
     deviceMotionEvent: 0,
     fullscreenChangeEvent: 0,
     pointerlockChangeEvent: 0,
     visibilityChangeEvent: 0,
     touchEvent: 0,
+#endif
+
+/* We do not depend on the exact initial values of falsey member fields - these
+   fields can be populated on-demand to save code size.
+   (but still documented here to keep track of what is supposed to be present)
 
     // When we transition from fullscreen to windowed mode, we remember here the
     // element that was just in fullscreen mode so that we can report
@@ -253,7 +258,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.keyEvent) JSEvents.keyEvent = _malloc({{{ C_STRUCTS.EmscriptenKeyboardEvent.__size__ }}});
+    JSEvents.keyEvent ||= _malloc({{{ C_STRUCTS.EmscriptenKeyboardEvent.__size__ }}});
 
     var keyEventHandlerFunc = (e) => {
 #if ASSERTIONS
@@ -507,7 +512,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.mouseEvent) JSEvents.mouseEvent = _malloc({{{ C_STRUCTS.EmscriptenMouseEvent.__size__ }}});
+    JSEvents.mouseEvent ||= _malloc({{{ C_STRUCTS.EmscriptenMouseEvent.__size__ }}});
     target = findEventTarget(target);
 
     var mouseEventHandlerFunc = (e = event) => {
@@ -598,7 +603,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.wheelEvent) JSEvents.wheelEvent = _malloc({{{ C_STRUCTS.EmscriptenWheelEvent.__size__ }}});
+    JSEvents.wheelEvent ||= _malloc({{{ C_STRUCTS.EmscriptenWheelEvent.__size__ }}});
 
     // The DOM Level 3 events spec event 'wheel'
     var wheelHandlerFunc = (e = event) => {
@@ -673,7 +678,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.uiEvent) JSEvents.uiEvent = _malloc({{{ C_STRUCTS.EmscriptenUiEvent.__size__ }}});
+    JSEvents.uiEvent ||= _malloc({{{ C_STRUCTS.EmscriptenUiEvent.__size__ }}});
 
 #if DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR
     target = findEventTarget(target);
@@ -745,7 +750,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.focusEvent) JSEvents.focusEvent = _malloc({{{ C_STRUCTS.EmscriptenFocusEvent.__size__ }}});
+    JSEvents.focusEvent ||= _malloc({{{ C_STRUCTS.EmscriptenFocusEvent.__size__ }}});
 
     var focusEventHandlerFunc = (e = event) => {
       var nodeName = JSEvents.getNodeNameForTarget(e.target);
@@ -809,7 +814,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.deviceOrientationEvent) JSEvents.deviceOrientationEvent = _malloc({{{ C_STRUCTS.EmscriptenDeviceOrientationEvent.__size__ }}});
+    JSEvents.deviceOrientationEvent ||= _malloc({{{ C_STRUCTS.EmscriptenDeviceOrientationEvent.__size__ }}});
 
     var deviceOrientationEventHandlerFunc = (e = event) => {
       fillDeviceOrientationEventData(JSEvents.deviceOrientationEvent, e, target); // TODO: Thread-safety with respect to emscripten_get_deviceorientation_status()
@@ -879,7 +884,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.deviceMotionEvent) JSEvents.deviceMotionEvent = _malloc({{{ C_STRUCTS.EmscriptenDeviceMotionEvent.__size__ }}});
+    JSEvents.deviceMotionEvent ||= _malloc({{{ C_STRUCTS.EmscriptenDeviceMotionEvent.__size__ }}});
 
     var deviceMotionEventHandlerFunc = (e = event) => {
       fillDeviceMotionEventData(JSEvents.deviceMotionEvent, e, target); // TODO: Thread-safety with respect to emscripten_get_devicemotion_status()
@@ -962,7 +967,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.orientationChangeEvent) JSEvents.orientationChangeEvent = _malloc({{{ C_STRUCTS.EmscriptenOrientationChangeEvent.__size__ }}});
+    JSEvents.orientationChangeEvent ||= _malloc({{{ C_STRUCTS.EmscriptenOrientationChangeEvent.__size__ }}});
 
     var orientationChangeEventHandlerFunc = (e = event) => {
 #if PTHREADS
@@ -1074,7 +1079,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.fullscreenChangeEvent) JSEvents.fullscreenChangeEvent = _malloc({{{ C_STRUCTS.EmscriptenFullscreenChangeEvent.__size__ }}});
+    JSEvents.fullscreenChangeEvent ||= _malloc({{{ C_STRUCTS.EmscriptenFullscreenChangeEvent.__size__ }}});
 
     var fullscreenChangeEventhandlerFunc = (e = event) => {
 #if PTHREADS
@@ -1200,9 +1205,9 @@ var LibraryHTML5 = {
 
     // If we are adding padding, must choose a background color or otherwise Chrome will give the
     // padding a default white color. Do it only if user has not customized their own background color.
-    if (!target.style.backgroundColor) target.style.backgroundColor = 'black';
+    target.style.backgroundColor ||= 'black';
     // IE11 does the same, but requires the color to be set in the document body.
-    if (!document.body.style.backgroundColor) document.body.style.backgroundColor = 'black'; // IE11
+    document.body.style.backgroundColor ||= 'black'; // IE11
     // Firefox always shows black letterboxes independent of style color.
 
     target.style.width = cssWidth + 'px';
@@ -1421,7 +1426,7 @@ var LibraryHTML5 = {
   $doRequestFullscreen: (target, strategy) => {
     if (!JSEvents.fullscreenEnabled()) return {{{ cDefs.EMSCRIPTEN_RESULT_NOT_SUPPORTED }}};
 #if !DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR
-    if (!target) target = '#canvas';
+    target ||= '#canvas';
 #endif
     target = findEventTarget(target);
     if (!target) return {{{ cDefs.EMSCRIPTEN_RESULT_UNKNOWN_TARGET }}};
@@ -1604,7 +1609,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.pointerlockChangeEvent) JSEvents.pointerlockChangeEvent = _malloc({{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.__size__ }}});
+    JSEvents.pointerlockChangeEvent ||= _malloc({{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.__size__ }}});
 
     var pointerlockChangeEventHandlerFunc = (e = event) => {
 #if PTHREADS
@@ -1742,7 +1747,7 @@ var LibraryHTML5 = {
   emscripten_request_pointerlock__deps: ['$JSEvents', '$requestPointerLock', '$findEventTarget'],
   emscripten_request_pointerlock: (target, deferUntilInEventHandler) => {
 #if !DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR
-    if (!target) target = '#canvas';
+    target ||= '#canvas';
 #endif
     target = findEventTarget(target);
     if (!target) return {{{ cDefs.EMSCRIPTEN_RESULT_UNKNOWN_TARGET }}};
@@ -1833,7 +1838,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.visibilityChangeEvent) JSEvents.visibilityChangeEvent = _malloc({{{ C_STRUCTS.EmscriptenVisibilityChangeEvent.__size__ }}});
+    JSEvents.visibilityChangeEvent ||= _malloc({{{ C_STRUCTS.EmscriptenVisibilityChangeEvent.__size__ }}});
 
     var visibilityChangeEventHandlerFunc = (e = event) => {
 #if PTHREADS
@@ -1887,7 +1892,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.touchEvent) JSEvents.touchEvent = _malloc({{{ C_STRUCTS.EmscriptenTouchEvent.__size__ }}});
+    JSEvents.touchEvent ||= _malloc({{{ C_STRUCTS.EmscriptenTouchEvent.__size__ }}});
 
     target = findEventTarget(target);
 
@@ -2035,7 +2040,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.gamepadEvent) JSEvents.gamepadEvent = _malloc({{{ C_STRUCTS.EmscriptenGamepadEvent.__size__ }}});
+    JSEvents.gamepadEvent ||= _malloc({{{ C_STRUCTS.EmscriptenGamepadEvent.__size__ }}});
 
     var gamepadEventHandlerFunc = (e = event) => {
 #if PTHREADS
@@ -2175,7 +2180,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    if (!JSEvents.batteryEvent) JSEvents.batteryEvent = _malloc({{{ C_STRUCTS.EmscriptenBatteryEvent.__size__ }}});
+    JSEvents.batteryEvent ||= _malloc({{{ C_STRUCTS.EmscriptenBatteryEvent.__size__ }}});
 
     var batteryEventHandlerFunc = (e = event) => {
 #if PTHREADS

src/library_html5_webgl.js

@@ -382,7 +382,7 @@ var LibraryHtml5WebGL = {
 #endif
 
 #if !DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR
-    if (!target) target = Module['canvas'];
+    target ||= Module['canvas'];
 #endif
 
     var webGlEventHandlerFunc = (e = event) => {

src/library_lz4.js

@@ -22,8 +22,7 @@ addToLibrary({
     },
     loadPackage(pack, preloadPlugin) {
       LZ4.init();
-      var compressedData = pack['compressedData'];
-      if (!compressedData) compressedData = LZ4.codec.compressPackage(pack['data']);
+      var compressedData = pack['compressedData'] || LZ4.codec.compressPackage(pack['data']);
       assert(compressedData['cachedIndexes'].length === compressedData['cachedChunks'].length);
       for (var i = 0; i < compressedData['cachedIndexes'].length; i++) {
         compressedData['cachedIndexes'][i] = -1;

src/library_sdl.js

@@ -2042,7 +2042,7 @@ var LibrarySDL = {
     SDL.eventHandlerContext = userdata;
 
     // All SDLEvents take the same amount of memory
-    if (!SDL.eventHandlerTemp) SDL.eventHandlerTemp = _malloc({{{ C_STRUCTS.SDL_KeyboardEvent.__size__ }}});
+    SDL.eventHandlerTemp ||= _malloc({{{ C_STRUCTS.SDL_KeyboardEvent.__size__ }}});
   },
 
   SDL_SetColors__proxy: 'sync',

src/library_stack_trace.js

@@ -58,8 +58,7 @@ var LibraryStackTrace = {
         lineno = parts[3];
         column = parts[4];
       } else {
-        parts = newFirefoxRe.exec(line);
-        if (!parts) parts = firefoxRe.exec(line);
+        parts = newFirefoxRe.exec(line) || firefoxRe.exec(line);
         if (parts && parts.length >= 4) {
           symbolName = parts[1];
           file = parts[2];

src/library_wasmfs.js

@@ -409,7 +409,7 @@ FS.init();
       }
       var path = PATH.join2(parent, name);
       var mode = FS_getMode(!!input, !!output);
-      if (!FS.createDevice.major) FS.createDevice.major = 64;
+      FS.createDevice.major ??= 64;
       var dev = FS.makedev(FS.createDevice.major++, 0);
       // Create a fake device with a set of stream ops to emulate
       // the old API's createDevice().

src/library_webgl.js

@@ -669,7 +669,7 @@ for (/**@suppress{duplicate}*/var i = 0; i <= {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
     },
 
     hookWebGL: function(glCtx) {
-      if (!glCtx) glCtx = this.detectWebGLContext();
+      glCtx ??= this.detectWebGLContext();
       if (!glCtx) return;
       if (!((typeof WebGLRenderingContext != 'undefined' && glCtx instanceof WebGLRenderingContext)
             || (typeof WebGL2RenderingContext != 'undefined' && glCtx instanceof WebGL2RenderingContext))) {
@@ -4161,8 +4161,7 @@ for (/**@suppress{duplicate}*/var i = 0; i <= {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
     var mem = _malloc(length), binding = emscriptenWebGLGetBufferBinding(target);
     if (!mem) return 0;
 
-    if (!GL.mappedBuffers[binding]) GL.mappedBuffers[binding] = {};
-    binding = GL.mappedBuffers[binding];
+    binding = GL.mappedBuffers[binding] ??= {};
     binding.offset = offset;
     binding.length = length;
     binding.mem = mem;

src/library_workerfs.js

@@ -12,7 +12,7 @@ addToLibrary({
     reader: null,
     mount(mount) {
       assert(ENVIRONMENT_IS_WORKER);
-      if (!WORKERFS.reader) WORKERFS.reader = new FileReaderSync();
+      WORKERFS.reader ??= new FileReaderSync();
       var root = WORKERFS.createNode(null, '/', WORKERFS.DIR_MODE, 0);
       var createdParents = {};
       function ensureParent(path) {

src/preamble.js

@@ -1076,7 +1076,7 @@ function createWasm() {
   }
 #endif
 
-  if (!wasmBinaryFile) wasmBinaryFile = findWasmBinary();
+  wasmBinaryFile ??= findWasmBinary();
 
 #if WASM_ASYNC_COMPILATION
 #if RUNTIME_DEBUG

src/shell.html

@@ -63,7 +63,7 @@
           return canvas;
         })(),
         setStatus: (text) => {
-          if (!Module.setStatus.last) Module.setStatus.last = { time: Date.now(), text: '' };
+          Module.setStatus.last ??= { time: Date.now(), text: '' };
           if (text === Module.setStatus.last.text) return;
           var m = text.match(/([^(]+)\((\d+(\.\d+)?)\/(\d+)\)/);
           var now = Date.now();

src/shell_minimal.html

@@ -102,7 +102,7 @@
           return canvas;
         })(),
         setStatus: (text) => {
-          if (!Module.setStatus.last) Module.setStatus.last = { time: Date.now(), text: '' };
+          Module.setStatus.last ??= { time: Date.now(), text: '' };
           if (text === Module.setStatus.last.text) return;
           var m = text.match(/([^(]+)\((\d+(\.\d+)?)\/(\d+)\)/);
           var now = Date.now();

test/other/codesize/test_codesize_cxx_ctors1.gzsize

@@ -1 +1 @@
-8455
+8451

test/other/codesize/test_codesize_cxx_ctors1.jssize

@@ -1 +1 @@
-20831
+20829

test/other/codesize/test_codesize_cxx_ctors2.gzsize

@@ -1 +1 @@
-8438
+8435

test/other/codesize/test_codesize_cxx_ctors2.jssize

@@ -1 +1 @@
-20799
+20797

test/other/codesize/test_codesize_cxx_except.gzsize

@@ -1 +1 @@
-9476
+9473

test/other/codesize/test_codesize_cxx_except.jssize

@@ -1 +1 @@
-24675
+24673

test/other/codesize/test_codesize_cxx_except_wasm.gzsize

@@ -1 +1 @@
-8415
+8411

test/other/codesize/test_codesize_cxx_except_wasm.jssize

@@ -1 +1 @@
-20725
+20723

test/other/codesize/test_codesize_cxx_except_wasm_exnref.gzsize

@@ -1 +1 @@
-8415
+8411

test/other/codesize/test_codesize_cxx_except_wasm_exnref.jssize

@@ -1 +1 @@
-20725
+20723

test/other/codesize/test_codesize_cxx_lto.gzsize

@@ -1 +1 @@
-8347
+8342

test/other/codesize/test_codesize_cxx_lto.jssize

@@ -1 +1 @@
-20408
+20407

test/other/codesize/test_codesize_cxx_mangle.gzsize

@@ -1 +1 @@
-9480
+9475

test/other/codesize/test_codesize_cxx_mangle.jssize

@@ -1 +1 @@
-24675
+24673

test/other/codesize/test_codesize_cxx_noexcept.gzsize

@@ -1 +1 @@
-8455
+8451

test/other/codesize/test_codesize_cxx_noexcept.jssize

@@ -1 +1 @@
-20831
+20829

test/other/codesize/test_codesize_files_js_fs.gzsize

@@ -1 +1 @@
-7581
+7584

test/other/codesize/test_codesize_files_js_fs.jssize

@@ -1 +1 @@
-18732
+18730

test/other/codesize/test_codesize_hello_O0.gzsize

@@ -1 +1 @@
-7983
+7985

test/other/codesize/test_codesize_hello_O1.gzsize

@@ -1 +1 @@
-2788
+2790