Use const in JS library code where values can be inlined

src/Fetch.js

@@ -666,7 +666,7 @@ function fetchXHR(fetch, onsuccess, onerror, onprogress, onreadystatechange) {
     // Specifies the maximum chunk size that a streaming fetch will transfer from
     // JS over to WebAssembly side. Used to cap a streaming fetch to avoid
     // overallocating WebAssembly memory needlessly.
-    var FETCH_STREAMING_MAX_CHUNK_SIZE = 8*1024*1024;
+    const FETCH_STREAMING_MAX_CHUNK_SIZE = 8*1024*1024;
 
     for (var bytePos = 0; bytePos < ptrLen || !ptrLen;) {
       var sz = Math.min(ptrLen - bytePos, FETCH_STREAMING_MAX_CHUNK_SIZE);

src/audio_worklet.js

@@ -123,13 +123,15 @@ function createWasmAudioWorkletProcessor() {
         outputViewsNeeded += entry.length;
       }
       stackMemoryData += outputViewsNeeded * this.bytesPerChannel;
-      var numParams = 0;
 #if AUDIO_WORKLET_SUPPORT_AUDIO_PARAMS
+      var numParams = 0;
       for (entry in parameters) {
         ++numParams;
         stackMemoryStruct += {{{ C_STRUCTS.AudioParamFrame.__size__ }}};
         stackMemoryData += parameters[entry].byteLength;
       }
+#else
+      const numParams = 0;
 #endif
       var oldStackPtr = stackSave();
 #if ASSERTIONS
@@ -185,7 +187,7 @@ function createWasmAudioWorkletProcessor() {
         dataPtr += subentry.length * {{{ getNativeTypeSize('float') }}};
       }
 #else
-      var paramsPtr = 0;
+      const paramsPtr = 0;
 #endif
 
       // Copy output audio descriptor structs to Wasm. 'outputsPtr' is the start

src/lib/libbrowser.js

@@ -101,7 +101,7 @@ var LibraryBrowser = {
             err(`warning: browser could not fully decode audio ${name}, trying slower base64 approach`);
             function encode64(data) {
               var BASE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
-              var PAD = '=';
+              const PAD = '=';
               var ret = '';
               var leftchar = 0;
               var leftbits = 0;
@@ -629,7 +629,7 @@ var LibraryBrowser = {
 
   emscripten_get_window_title__proxy: 'sync',
   emscripten_get_window_title: () => {
-    var buflen = 256;
+    const buflen = 256;
 
     if (!_emscripten_get_window_title.buffer) {
       _emscripten_get_window_title.buffer = _malloc(buflen);

src/lib/libdylink.js

@@ -494,15 +494,15 @@ var LibraryDylink = {
     }
 
     var customSection = { neededDynlibs: [], tlsExports: new Set(), weakImports: new Set(), runtimePaths: [] };
-    var WASM_DYLINK_MEM_INFO = 0x1;
-    var WASM_DYLINK_NEEDED = 0x2;
-    var WASM_DYLINK_EXPORT_INFO = 0x3;
-    var WASM_DYLINK_IMPORT_INFO = 0x4;
-    var WASM_DYLINK_RUNTIME_PATH = 0x5;
-    var WASM_DYLINK_TARGET_ARCH = 0x6;
-    var WASM_SYMBOL_TLS = 0x100;
-    var WASM_SYMBOL_BINDING_MASK = 0x3;
-    var WASM_SYMBOL_BINDING_WEAK = 0x1;
+    const WASM_DYLINK_MEM_INFO = 0x1;
+    const WASM_DYLINK_NEEDED = 0x2;
+    const WASM_DYLINK_EXPORT_INFO = 0x3;
+    const WASM_DYLINK_IMPORT_INFO = 0x4;
+    const WASM_DYLINK_RUNTIME_PATH = 0x5;
+    const WASM_DYLINK_TARGET_ARCH = 0x6;
+    const WASM_SYMBOL_TLS = 0x100;
+    const WASM_SYMBOL_BINDING_MASK = 0x3;
+    const WASM_SYMBOL_BINDING_WEAK = 0x1;
     while (offset < end) {
       var subsectionType = getU8();
       var subsectionSize = getLEB();
@@ -1052,7 +1052,7 @@ var LibraryDylink = {
     return withStackSave(() => {
       // In dylink.c we use: `char buf[2*NAME_MAX+2];` and NAME_MAX is 255.
       // So we use the same size here.
-      var bufSize = 2*255 + 2;
+      const bufSize = 2*255 + 2;
       var buf = stackAlloc(bufSize);
       var rpathC = stringToUTF8OnStack(rpathResolved.join(':'));
       var libNameC = stringToUTF8OnStack(libName);

src/lib/libembind.js

@@ -451,7 +451,7 @@ var LibraryEmbind = {
     '$stringToUTF8', '$lengthBytesUTF8', 'malloc', 'free'],
   _embind_register_std_string: (rawType, name) => {
     name = AsciiToString(name);
-    var stdStringIsUTF8 = {{{ EMBIND_STD_STRING_IS_UTF8 }}};
+    const stdStringIsUTF8 = {{{ EMBIND_STD_STRING_IS_UTF8 }}};
 
     registerType(rawType, {
       name,

src/lib/libemval.js

@@ -289,7 +289,7 @@ var LibraryEmVal = {
     '$Emval', '$getStringOrSymbol',
   ],
   _emval_create_invoker: (argCount, argTypesPtr, kind) => {
-    var GenericWireTypeSize = {{{ 2 * POINTER_SIZE }}};
+    const GenericWireTypeSize = {{{ 2 * POINTER_SIZE }}};
 
     var [retType, ...argTypes] = emval_lookupTypes(argCount, argTypesPtr);
     var toReturnWire = retType.toWireType.bind(retType);

src/lib/libglemu.js

@@ -990,72 +990,72 @@ var LibraryGLEmulation = {
     TexEnvJIT: null,
     spawnTexEnvJIT: () => {
       // GL defs:
-      var GL_TEXTURE0 = 0x84C0;
-      var GL_TEXTURE_1D = 0xDE0;
-      var GL_TEXTURE_2D = 0xDE1;
-      var GL_TEXTURE_3D = 0x806f;
-      var GL_TEXTURE_CUBE_MAP = 0x8513;
-      var GL_TEXTURE_ENV = 0x2300;
-      var GL_TEXTURE_ENV_MODE = 0x2200;
-      var GL_TEXTURE_ENV_COLOR = 0x2201;
-      var GL_TEXTURE_CUBE_MAP_POSITIVE_X = 0x8515;
-      var GL_TEXTURE_CUBE_MAP_NEGATIVE_X = 0x8516;
-      var GL_TEXTURE_CUBE_MAP_POSITIVE_Y = 0x8517;
-      var GL_TEXTURE_CUBE_MAP_NEGATIVE_Y = 0x8518;
-      var GL_TEXTURE_CUBE_MAP_POSITIVE_Z = 0x8519;
-      var GL_TEXTURE_CUBE_MAP_NEGATIVE_Z = 0x851A;
-
-      var GL_SRC0_RGB = 0x8580;
-      var GL_SRC1_RGB = 0x8581;
-      var GL_SRC2_RGB = 0x8582;
-
-      var GL_SRC0_ALPHA = 0x8588;
-      var GL_SRC1_ALPHA = 0x8589;
-      var GL_SRC2_ALPHA = 0x858A;
-
-      var GL_OPERAND0_RGB = 0x8590;
-      var GL_OPERAND1_RGB = 0x8591;
-      var GL_OPERAND2_RGB = 0x8592;
-
-      var GL_OPERAND0_ALPHA = 0x8598;
-      var GL_OPERAND1_ALPHA = 0x8599;
-      var GL_OPERAND2_ALPHA = 0x859A;
-
-      var GL_COMBINE_RGB = 0x8571;
-      var GL_COMBINE_ALPHA = 0x8572;
-
-      var GL_RGB_SCALE = 0x8573;
-      var GL_ALPHA_SCALE = 0xD1C;
+      const GL_TEXTURE0 = 0x84C0;
+      const GL_TEXTURE_1D = 0xDE0;
+      const GL_TEXTURE_2D = 0xDE1;
+      const GL_TEXTURE_3D = 0x806f;
+      const GL_TEXTURE_CUBE_MAP = 0x8513;
+      const GL_TEXTURE_ENV = 0x2300;
+      const GL_TEXTURE_ENV_MODE = 0x2200;
+      const GL_TEXTURE_ENV_COLOR = 0x2201;
+      const GL_TEXTURE_CUBE_MAP_POSITIVE_X = 0x8515;
+      const GL_TEXTURE_CUBE_MAP_NEGATIVE_X = 0x8516;
+      const GL_TEXTURE_CUBE_MAP_POSITIVE_Y = 0x8517;
+      const GL_TEXTURE_CUBE_MAP_NEGATIVE_Y = 0x8518;
+      const GL_TEXTURE_CUBE_MAP_POSITIVE_Z = 0x8519;
+      const GL_TEXTURE_CUBE_MAP_NEGATIVE_Z = 0x851A;
+
+      const GL_SRC0_RGB = 0x8580;
+      const GL_SRC1_RGB = 0x8581;
+      const GL_SRC2_RGB = 0x8582;
+
+      const GL_SRC0_ALPHA = 0x8588;
+      const GL_SRC1_ALPHA = 0x8589;
+      const GL_SRC2_ALPHA = 0x858A;
+
+      const GL_OPERAND0_RGB = 0x8590;
+      const GL_OPERAND1_RGB = 0x8591;
+      const GL_OPERAND2_RGB = 0x8592;
+
+      const GL_OPERAND0_ALPHA = 0x8598;
+      const GL_OPERAND1_ALPHA = 0x8599;
+      const GL_OPERAND2_ALPHA = 0x859A;
+
+      const GL_COMBINE_RGB = 0x8571;
+      const GL_COMBINE_ALPHA = 0x8572;
+
+      const GL_RGB_SCALE = 0x8573;
+      const GL_ALPHA_SCALE = 0xD1C;
 
       // env.mode
-      var GL_ADD      = 0x104;
-      var GL_BLEND    = 0xBE2;
-      var GL_REPLACE  = 0x1E01;
-      var GL_MODULATE = 0x2100;
-      var GL_DECAL    = 0x2101;
-      var GL_COMBINE  = 0x8570;
+      const GL_ADD      = 0x104;
+      const GL_BLEND    = 0xBE2;
+      const GL_REPLACE  = 0x1E01;
+      const GL_MODULATE = 0x2100;
+      const GL_DECAL    = 0x2101;
+      const GL_COMBINE  = 0x8570;
 
       // env.color/alphaCombiner
-      //var GL_ADD         = 0x104;
-      //var GL_REPLACE     = 0x1E01;
-      //var GL_MODULATE    = 0x2100;
-      var GL_SUBTRACT    = 0x84E7;
-      var GL_INTERPOLATE = 0x8575;
+      //const GL_ADD         = 0x104;
+      //const GL_REPLACE     = 0x1E01;
+      //const GL_MODULATE    = 0x2100;
+      const GL_SUBTRACT    = 0x84E7;
+      const GL_INTERPOLATE = 0x8575;
 
       // env.color/alphaSrc
-      var GL_TEXTURE       = 0x1702;
-      var GL_CONSTANT      = 0x8576;
-      var GL_PRIMARY_COLOR = 0x8577;
-      var GL_PREVIOUS      = 0x8578;
+      const GL_TEXTURE       = 0x1702;
+      const GL_CONSTANT      = 0x8576;
+      const GL_PRIMARY_COLOR = 0x8577;
+      const GL_PREVIOUS      = 0x8578;
 
       // env.color/alphaOp
-      var GL_SRC_COLOR           = 0x300;
-      var GL_ONE_MINUS_SRC_COLOR = 0x301;
-      var GL_SRC_ALPHA           = 0x302;
-      var GL_ONE_MINUS_SRC_ALPHA = 0x303;
+      const GL_SRC_COLOR           = 0x300;
+      const GL_ONE_MINUS_SRC_COLOR = 0x301;
+      const GL_SRC_ALPHA           = 0x302;
+      const GL_ONE_MINUS_SRC_ALPHA = 0x303;
 
-      var GL_RGB  = 0x1907;
-      var GL_RGBA = 0x1908;
+      const GL_RGB  = 0x1907;
+      const GL_RGBA = 0x1908;
 
       // Our defs:
       var TEXENVJIT_NAMESPACE_PREFIX = 'tej_';
@@ -2174,7 +2174,7 @@ var LibraryGLEmulation = {
           var uTexUnitPrefix = 'u_texUnit';
           var aTexCoordPrefix = 'a_texCoord';
           var vTexCoordPrefix = 'v_texCoord';
-          var vPrimColor = 'v_color';
+          const vPrimColor = 'v_color';
           var uTexMatrixPrefix = GLImmediate.useTextureMatrix ? 'u_textureMatrix' : null;
 
           if (useCurrProgram) {

src/lib/libhtml5.js

@@ -276,7 +276,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenKeyboardEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenKeyboardEvent.__size__ }}};
     JSEvents.keyEvent ||= _malloc(eventSize);
 
     var keyEventHandlerFunc = (e) => {
@@ -507,7 +507,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenMouseEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenMouseEvent.__size__ }}};
     JSEvents.mouseEvent ||= _malloc(eventSize);
     target = findEventTarget(target);
 
@@ -603,7 +603,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenWheelEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenWheelEvent.__size__ }}};
     JSEvents.wheelEvent ||= _malloc(eventSize)
 
     // The DOM Level 3 events spec event 'wheel'
@@ -654,7 +654,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenUiEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenUiEvent.__size__ }}};
     JSEvents.uiEvent ||= _malloc(eventSize);
 
 #if DISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR
@@ -726,7 +726,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenFocusEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenFocusEvent.__size__ }}};
     JSEvents.focusEvent ||= _malloc(eventSize);
 
     var focusEventHandlerFunc = (e) => {
@@ -789,7 +789,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenDeviceOrientationEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenDeviceOrientationEvent.__size__ }}};
     JSEvents.deviceOrientationEvent ||= _malloc(eventSize);
 
     var deviceOrientationEventHandlerFunc = (e) => {
@@ -856,7 +856,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenDeviceMotionEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenDeviceMotionEvent.__size__ }}};
     JSEvents.deviceMotionEvent ||= _malloc(eventSize);
 
     var deviceMotionEventHandlerFunc = (e) => {
@@ -935,7 +935,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenOrientationChangeEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenOrientationChangeEvent.__size__ }}};
     JSEvents.orientationChangeEvent ||= _malloc(eventSize);
 
     var orientationChangeEventHandlerFunc = (e) => {
@@ -1037,7 +1037,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenFullscreenChangeEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenFullscreenChangeEvent.__size__ }}};
     JSEvents.fullscreenChangeEvent ||= _malloc(eventSize);
 
     var fullscreenChangeEventHandlerFunc = (e) => {
@@ -1521,7 +1521,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.__size__ }}};
     JSEvents.pointerlockChangeEvent ||= _malloc(eventSize);
 
     var pointerlockChangeEventHandlerFunc = (e) => {
@@ -1719,7 +1719,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenVisibilityChangeEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenVisibilityChangeEvent.__size__ }}};
     JSEvents.visibilityChangeEvent ||= _malloc(eventSize);
 
     var visibilityChangeEventHandlerFunc = (e) => {
@@ -1772,7 +1772,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenTouchEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenTouchEvent.__size__ }}};
     JSEvents.touchEvent ||= _malloc(eventSize);
 
     target = findEventTarget(target);
@@ -1906,7 +1906,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenGamepadEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenGamepadEvent.__size__ }}};
     JSEvents.gamepadEvent ||= _malloc(eventSize);
 
     var gamepadEventHandlerFunc = (e) => {
@@ -2049,7 +2049,7 @@ var LibraryHTML5 = {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
 #endif
-    var eventSize = {{{ C_STRUCTS.EmscriptenBatteryEvent.__size__ }}};
+    const eventSize = {{{ C_STRUCTS.EmscriptenBatteryEvent.__size__ }}};
     JSEvents.batteryEvent ||= _malloc(eventSize)
 
     var batteryEventHandlerFunc = (e) => {

src/lib/libmemfs.js

@@ -115,7 +115,7 @@ addToLibrary({
       // For small filesizes (<1MB), perform size*2 geometric increase, but for
       // large sizes, do a much more conservative size*1.125 increase to avoid
       // overshooting the allocation cap by a very large margin.
-      var CAPACITY_DOUBLING_MAX = 1024 * 1024;
+      const CAPACITY_DOUBLING_MAX = 1024 * 1024;
       newCapacity = Math.max(newCapacity, (prevCapacity * (prevCapacity < CAPACITY_DOUBLING_MAX ? 2.0 : 1.125)) >>> 0);
       if (prevCapacity) newCapacity = Math.max(newCapacity, 256); // At minimum allocate 256b for each file when expanding.
       var oldContents = MEMFS.getFileDataAsTypedArray(node);

src/lib/libopenal.js

@@ -1779,7 +1779,7 @@ var LibraryOpenAL = {
       // Have to pick a size from 256, 512, 1024, 2048, 4096, 8192, 16384.
       // One can also set it to zero, which leaves the decision up to the impl.
       // An extension could allow specifying this value.
-      var processorFrameCount = 512;
+      const processorFrameCount = 512;
 
       newCapture.scriptProcessorNode = newCapture.audioCtx.createScriptProcessor(
         processorFrameCount, inputChannelCount, outputChannelCount

src/lib/libsdl.js

@@ -2717,7 +2717,7 @@ var LibrarySDL = {
     // In particular, see https://bugzil.la/654787 and https://bugzil.la/1012801 for tradeoffs.
     var canPlayWithWebAudio = !Module['SDL_canPlayWithWebAudio'] || Module['SDL_canPlayWithWebAudio'](filename, arrayBuffer);
 #else
-    var canPlayWithWebAudio = true;
+    const canPlayWithWebAudio = true;
 #endif
 
     if (bytes !== undefined && SDL.webAudioAvailable() && canPlayWithWebAudio) {