Enable STRICT_JS by default

ChangeLog.md

@@ -35,6 +35,10 @@ See docs/process.md for more on how version tagging works.
 - SDL2 port updated to include stub functions for `SDL_hid_init()` and related
   functions. (#26297)
 - libpng port updated from 1.6.39 to 1.6.55. (#26388)
+- The `STRICT_JS` setting is now on by default.  Previously it was enabled by
+  default in `STRICT` mode.  If you have EM_ASM or EM_JS or `--pre-js` code
+  that does not conform to JS strict mode then you maybe need to disable this
+  with `-sSTRICT_JS=0`. (#26421)
 
 5.0.2 - 02/25/26
 ----------------

site/source/docs/tools_reference/settings_reference.rst

@@ -1703,7 +1703,6 @@ Changes enabled by this:
 
   - The C define EMSCRIPTEN is not defined (__EMSCRIPTEN__ always is, and
     is the correct thing to use).
-  - STRICT_JS is enabled.
   - IGNORE_MISSING_MAIN is disabled.
   - AUTO_JS_LIBRARIES is disabled.
   - AUTO_NATIVE_LIBRARIES is disabled.
@@ -1734,7 +1733,7 @@ STRICT_JS
 
 Add ``"use strict;"`` to generated JS
 
-Default value: false
+Default value: true
 
 .. _warn_on_undefined_symbols:
 

src/lib/libglemu.js

@@ -34,43 +34,41 @@ var LibraryGLEmulation = {
     'glVertexAttribPointer', 'glActiveTexture', '$stringToNewUTF8',
     '$ptrToString', '$getEmscriptenSupportedExtensions',
   ],
-  $GLEmulation__postset:
-#if MAYBE_CLOSURE_COMPILER
-    // Forward declare GL functions that are overridden by GLEmulation here to appease Closure compiler.
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glDrawArrays;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glDrawElements;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glActiveTexture;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glEnable;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glDisable;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glTexEnvf;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glTexEnvi;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glTexEnvfv;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetIntegerv;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glIsEnabled;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetBooleanv;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetString;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glCreateShader;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glShaderSource;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glCompileShader;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glAttachShader;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glDetachShader;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glUseProgram;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glDeleteProgram;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glBindAttribLocation;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glLinkProgram;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glBindBuffer;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetFloatv;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glHint;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glEnableVertexAttribArray;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glDisableVertexAttribArray;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _emscripten_glVertexAttribPointer;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _glTexEnvf;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _glTexEnvi;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _glTexEnvfv;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _glGetTexEnviv;' +
-    '/**@suppress {duplicate, undefinedVars}*/var _glGetTexEnvfv;' +
-#endif
-    'GLEmulation.init();',
+  $GLEmulation__postset: `
+    // Forward declare GL functions that are overridden by GLEmulation.
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDrawArrays;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDrawElements;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glActiveTexture;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glEnable;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDisable;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glTexEnvf;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glTexEnvi;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glTexEnvfv;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetIntegerv;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glIsEnabled;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetBooleanv;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetString;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glCreateShader;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glShaderSource;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glCompileShader;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glAttachShader;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDetachShader;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glUseProgram;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDeleteProgram;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glBindAttribLocation;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glLinkProgram;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glBindBuffer;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glGetFloatv;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glHint;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glEnableVertexAttribArray;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDisableVertexAttribArray;
+    /**@suppress {duplicate, undefinedVars}*/var _emscripten_glVertexAttribPointer;
+    /**@suppress {duplicate, undefinedVars}*/var _glTexEnvf;
+    /**@suppress {duplicate, undefinedVars}*/var _glTexEnvi;
+    /**@suppress {duplicate, undefinedVars}*/var _glTexEnvfv;
+    /**@suppress {duplicate, undefinedVars}*/var _glGetTexEnviv;
+    /**@suppress {duplicate, undefinedVars}*/var _glGetTexEnvfv;
+    GLEmulation.init();`,
   $GLEmulation: {
     // Fog support. Partial, we assume shaders are used that implement fog. We just pass them uniforms
     fogStart: 0,

src/settings.js

@@ -1162,7 +1162,6 @@ var LINKABLE = false;
 //
 //   - The C define EMSCRIPTEN is not defined (__EMSCRIPTEN__ always is, and
 //     is the correct thing to use).
-//   - STRICT_JS is enabled.
 //   - IGNORE_MISSING_MAIN is disabled.
 //   - AUTO_JS_LIBRARIES is disabled.
 //   - AUTO_NATIVE_LIBRARIES is disabled.
@@ -1181,7 +1180,7 @@ var IGNORE_MISSING_MAIN = true;
 
 // Add ``"use strict;"`` to generated JS
 // [link]
-var STRICT_JS = false;
+var STRICT_JS = true;
 
 // If set to 1, we will warn on any undefined symbols that are not resolved by
 // the ``library_*.js`` files. Note that it is common in large projects to not

test/browser/glut_touchevents.c

@@ -68,7 +68,6 @@ int main(int argc, char *argv[])
         touches.item = function(i) { return this[i]; };
 
         var event = document.createEvent('UIEvent');
-        event.target = Module['canvas'];
         event.button = 0;
         event.changedTouches = touches;
         event.initUIEvent(eventType, true, true, window, 1);

test/codesize/test_unoptimized_code_size.json

@@ -1,16 +1,16 @@
 {
-  "hello_world.js": 57007,
-  "hello_world.js.gz": 17736,
+  "hello_world.js": 57022,
+  "hello_world.js.gz": 17744,
   "hello_world.wasm": 15138,
   "hello_world.wasm.gz": 7455,
-  "no_asserts.js": 26576,
-  "no_asserts.js.gz": 8881,
+  "no_asserts.js": 26591,
+  "no_asserts.js.gz": 8894,
   "no_asserts.wasm": 12187,
   "no_asserts.wasm.gz": 5984,
   "strict.js": 54825,
   "strict.js.gz": 17039,
   "strict.wasm": 15138,
   "strict.wasm.gz": 7450,
-  "total": 180871,
-  "total_gz": 64545
+  "total": 180901,
+  "total_gz": 64566
 }

test/embind/test_pthreads.cpp

@@ -8,7 +8,7 @@ using namespace emscripten;
 
 void thread(void) {
   EM_ASM({
-    globalProperty = {
+    globalThis.globalProperty = {
       foo: function(value) {
         return value;
       }

test/other/test_runtime_keepalive.cpp

@@ -8,7 +8,7 @@ int main() {
     Module["onExit"] = () => { out("onExit"); };
     runtimeKeepalivePush();
     out("runtimeKeepalivePush done");
-    counter = 0;
+    var counter = 0;
     function timerCallback() {
       if (counter < 5) {
         runtimeKeepalivePush();

test/test_browser.py

@@ -944,7 +944,7 @@ def test_sdl_stb_image_cleanup(self):
     'safe_heap_O2': (['-sSAFE_HEAP', '-O2'],),
   })
   def test_sdl_canvas(self, args):
-    self.btest_exit('test_sdl_canvas.c', cflags=['-sLEGACY_GL_EMULATION', '-lSDL', '-lGL'] + args)
+    self.btest_exit('test_sdl_canvas.c', cflags=['-sSTRICT_JS', '-sLEGACY_GL_EMULATION', '-lSDL', '-lGL'] + args)
 
   def test_sdl_canvas_alpha(self):
     # N.B. On Linux with Intel integrated graphics cards, this test needs Firefox 49 or newer.
@@ -1058,7 +1058,7 @@ def test_sdl_mouse_offsets(self):
     self.run_browser('page.html', '', '/report_result?exit:0')
 
   def test_glut_touchevents(self):
-    self.btest_exit('glut_touchevents.c', cflags=['-lglut'])
+    self.btest_exit('glut_touchevents.c', cflags=['-lglut', '-sSTRICT_JS'])
 
   def test_glut_wheelevents(self):
     self.btest_exit('glut_wheelevents.c', cflags=['-lglut'])

test/test_core.py

@@ -411,7 +411,6 @@ def decorated(self, textdecoder, *args, **kwargs):
 
 no_safe_heap = make_no_decorator_for_setting('SAFE_HEAP')
 no_strict = make_no_decorator_for_setting('STRICT')
-no_strict_js = make_no_decorator_for_setting('STRICT_JS')
 no_big_endian = make_no_decorator_for_setting('SUPPORT_BIG_ENDIAN')
 no_omit_asm_module_exports = make_no_decorator_for_setting('DECLARE_ASM_MODULE_EXPORTS=0')
 no_js_math = make_no_decorator_for_setting('JS_MATH')
@@ -6306,7 +6305,6 @@ def test_jslib(self):
   @with_env_modify({'LC_ALL': 'latin-1', 'PYTHONUTF8': '0', 'PYTHONCOERCECLOCALE': '0'})
   @crossplatform
   @no_modularize_instance('uses MODULARIZE')
-  @no_strict_js('MODULARIZE is not compatible with STRICT_JS')
   @no_omit_asm_module_exports('MODULARIZE is not compatible with DECLARE_ASM_MODULE_EXPORTS=0')
   def test_unicode_js_library(self):
     # First verify that we have correct overridden the default python file encoding.
@@ -8038,7 +8036,6 @@ def get_wat_addr(call_index):
 
   @no_omit_asm_module_exports('MODULARIZE is not compatible with DECLARE_ASM_MODULE_EXPORTS=0')
   @no_modularize_instance('uses -sMODULARIZE')
-  @no_strict_js('MODULARIZE is not compatible with STRICT_JS')
   def test_modularize_closure_pre(self):
     # test that the combination of modularize + closure + pre-js works. in that mode,
     # closure should not minify the Module object in a way that the pre-js cannot use it.
@@ -8985,7 +8982,6 @@ def test_asan_api(self):
     self.do_core_test('test_asan_api.c', cflags=['-fsanitize=address'])
 
   @asan
-  @no_strict_js('MODULARIZE is not compatible with STRICT_JS')
   @no_omit_asm_module_exports('MODULARIZE is not compatible with DECLARE_ASM_MODULE_EXPORTS=0')
   @no_modularize_instance('uses MODULARIZE')
   def test_asan_modularized_with_closure(self):
@@ -9680,7 +9676,6 @@ def test_esm_integration(self):
     self.assertFileContents(test_file('core/test_esm_integration.expected.mjs'), read_file('hello_world.mjs'))
 
   @no_omit_asm_module_exports('MODULARIZE is not compatible with DECLARE_ASM_MODULE_EXPORTS=0')
-  @no_strict_js('MODULARIZE is not compatible with STRICT_JS')
   def test_modularize_instance_hello(self):
     self.do_core_test('test_hello_world.c', cflags=['-sMODULARIZE=instance', '-Wno-experimental'])
 
@@ -9689,7 +9684,6 @@ def test_modularize_instance_hello(self):
     'pthreads': (['-pthread'],),
   })
   @no_omit_asm_module_exports('MODULARIZE is not compatible with DECLARE_ASM_MODULE_EXPORTS=0')
-  @no_strict_js('MODULARIZE is not compatible with STRICT_JS')
   def test_modularize_instance(self, args):
     if args:
       self.require_pthreads()
@@ -9725,7 +9719,6 @@ def test_modularize_instance(self, args):
 
   @no_omit_asm_module_exports('MODULARIZE is not compatible with DECLARE_ASM_MODULE_EXPORTS=0')
   @no_4gb('EMBIND_AOT can\'t lower 4gb')
-  @no_strict_js('MODULARIZE is not compatible with STRICT_JS')
   def test_modularize_instance_embind(self):
     self.run_process([EMXX, test_file('modularize_instance_embind.cpp'),
                       '-sMODULARIZE=instance',
@@ -9905,7 +9898,6 @@ def setUp(self):
 
 # Add DEFAULT_TO_CXX=0
 strict = make_run('strict', cflags=[], settings={'STRICT': 1})
-strict_js = make_run('strict_js', cflags=[], settings={'STRICT_JS': 1})
 
 ubsan = make_run('ubsan', cflags=['-fsanitize=undefined', '--profiling'])
 lsan = make_run('lsan', cflags=['-fsanitize=leak', '--profiling'], settings={'ALLOW_MEMORY_GROWTH': 1})

tools/link.py

@@ -1147,9 +1147,10 @@ def limit_incoming_module_api():
   elif options.shell_html:
     diagnostics.warning('unused-command-line-argument', '--shell-file ignored when not generating html output')
 
+  if settings.EXPORT_ES6 or settings.MODULARIZE:
+    default_setting('STRICT_JS', 0)
+
   if settings.STRICT:
-    if not settings.MODULARIZE:
-      default_setting('STRICT_JS', 1)
     default_setting('DEFAULT_TO_CXX', 0)
     default_setting('IGNORE_MISSING_MAIN', 0)
     default_setting('AUTO_NATIVE_LIBRARIES', 0)