[mimalloc] Error on mimalloc + ASan (#23314)

mimalloc is not meant to be used with ASan in general, see

#23288 (comment)

Fixes #23288

test/test_core.py

@@ -8909,10 +8909,6 @@ def test_asan_no_error(self, name):
     'vector': ('test_asan_vector.cpp', [
       'AddressSanitizer: container-overflow on address'
     ]),
-    # some coverage for mimalloc as well
-    'use_after_free_c_mimalloc': ('test_asan_use_after_free.c', [
-      'AddressSanitizer: heap-use-after-free on address',
-    ], ['-sMALLOC=mimalloc']),
   })
   def test_asan(self, name, expected_output, cflags=None):
     if '-Oz' in self.emcc_args:

test/test_other.py

@@ -15218,6 +15218,11 @@ def test_wasm64_no_asan(self):
     err = self.expect_fail([EMCC, test_file('hello_world.c'), '-sMEMORY64', '-fsanitize=address'])
     self.assertContained('error: MEMORY64 does not yet work with ASAN', err)
 
+  def test_mimalloc_no_asan(self):
+    # See https://github.com/emscripten-core/emscripten/issues/23288#issuecomment-2571648258
+    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-sMALLOC=mimalloc', '-fsanitize=address'])
+    self.assertContained('error: mimalloc is not compatible with -fsanitize=address', err)
+
   @crossplatform
   def test_js_preprocess_pre_post(self):
     create_file('pre.js', '''

tools/system_libs.py

@@ -2369,6 +2369,9 @@ def add_sanitizer_libs():
     add_library('libc')
     if settings.MALLOC == 'mimalloc':
       add_library('libmimalloc')
+      if settings.USE_ASAN:
+        # See https://github.com/emscripten-core/emscripten/issues/23288#issuecomment-2571648258
+        shared.exit_with_error('mimalloc is not compatible with -fsanitize=address')
     elif settings.MALLOC != 'none':
       add_library('libmalloc')
   add_library('libcompiler_rt')