Skip export wrapper for stackRestore function. (#21554)

The `stackRestore` function used by `invoke_xxx` wrappers and gets
called as the stack unwinds after a call to `exit`.

Alternatively we could add a check in each of the `invoke_xxx` wrappers
to avoid calling `stackRestore`, but that doesn't seem worth it.

Fixes: #21474

Author: sbc100

test/other/test_exceptions_exit_runtime.cpp

@@ -0,0 +1,20 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void foo() {
+  printf("foo\n");
+  exit(0);
+}
+
+int main() {
+  printf("main\n");
+  try {
+    // `foo` calls `exit()` which triggers the runtime to exit and then
+    // the stack to unwind.
+    // This test verifies that we don't error during the unwinding due
+    // to the runtime having already exited.
+    foo();
+  } catch(...) {
+    printf("caught\n");
+  }
+}

test/other/test_exceptions_exit_runtime.out

@@ -0,0 +1,2 @@
+main
+foo

test/test_other.py

@@ -8998,6 +8998,19 @@ def test_exceptions_rethrow_stack_trace_and_message(self, wasm_eh):
                       expected_output=rethrow_stack_trace_checks, regex=True)
     self.assertNotContained('important_function', err)
 
+  @parameterized({
+    '': (False,),
+    'wasm': (True,),
+  })
+  def test_exceptions_exit_runtime(self, wasm_eh):
+    self.set_setting('EXIT_RUNTIME')
+    if wasm_eh:
+      self.require_wasm_eh()
+      self.emcc_args.append('-fwasm-exceptions')
+    else:
+      self.set_setting('DISABLE_EXCEPTION_CATCHING', 0)
+    self.do_other_test('test_exceptions_exit_runtime.cpp')
+
   @requires_node
   def test_jsrun(self):
     print(config.NODE_JS)

tools/emscripten.py

@@ -822,18 +822,20 @@ def make_export_wrappers(function_exports):
 
   wrappers = []
 
-  # The emscripten stack functions are called very early (by writeStackCookie) before
-  # the runtime is initialized so we can't create these wrappers that check for
-  # runtimeInitialized.
-  # Likewise `__trap` can occur before the runtime is initialized since it is used in
-  # abort.
-  # pthread_self and _emscripten_proxy_execute_task_queue are currently called in some
-  # cases after the runtime has exited.
-  # TODO: Look into removing these, and improving our robustness around thread termination.
   def install_wrapper(sym):
+    # The emscripten stack functions are called very early (by writeStackCookie) before
+    # the runtime is initialized so we can't create these wrappers that check for
+    # runtimeInitialized.
     if sym.startswith('_asan_') or sym.startswith('emscripten_stack_'):
       return False
-    if sym in ('__trap', 'pthread_self', '_emscripten_proxy_execute_task_queue'):
+    # Likewise `__trap` can occur before the runtime is initialized since it is used in
+    # abort.
+    # stackRestore is often called during stack unwinding (e.g. by invoke_xxx function) which
+    # runs after the runtime has exited.
+    # pthread_self and _emscripten_proxy_execute_task_queue are currently called in some
+    # cases after the runtime has exited.
+    # TODO: Look into removing these, and improving our robustness around thread termination.
+    if sym in ('__trap', 'pthread_self', '_emscripten_proxy_execute_task_queue', 'stackRestore'):
       return False
     return True