Automatically report exit status in browser tests (#12928)

This means that tests don't necessarily need to call REPORT_RESULT.

I'm going to be taking advantage of this in #12923.

Also, don't initialize EXIT_STATUS to zero, but leave it as undefined.
It seems useful to be able to tell the diference between a program that
exits with a zero status and one that has not in fact exited yet.

Author: sbc100

tests/browser_reporting.js

@@ -1,3 +1,5 @@
+var hasModule = typeof Module === 'object' && Module;
+
 /** @param {boolean=} sync
     @param {number=} port */
 function reportResultToServer(result, sync, port) {
@@ -7,9 +9,7 @@ function reportResultToServer(result, sync, port) {
     reportErrorToServer("excessive reported results, sending " + result + ", test will fail");
   }
   reportResultToServer.reported = true;
-
   var xhr = new XMLHttpRequest();
-  var hasModule = typeof Module === 'object' && Module;
   if (hasModule && Module['pageThrewException']) result = 12345;
   xhr.open('GET', 'http://localhost:' + port + '/report_result?' + result, !sync);
   xhr.send();
@@ -36,3 +36,9 @@ if (typeof window === 'object' && window) {
     xhr.send();
   });
 }
+
+if (hasModule) {
+  Module['onExit'] = function(status) {
+    maybeReportResultToServer('exit:' + status);
+  }
+}

tests/runner.py

@@ -1484,22 +1484,26 @@ def reftest(self, expected, manually_trigger=False):
       }
 ''' % (reporting.read(), basename, int(manually_trigger)))
 
-  def compile_btest(self, args):
+  def compile_btest(self, args, reporting=True):
     # add in support for reporting results. this adds an include a header so testcases can
     # use REPORT_RESULT, and also adds a cpp file to be compiled alongside the testcase, which
     # contains the implementation of REPORT_RESULT (we can't just include that implementation in
     # the header as there may be multiple files being compiled here).
-    args += ['-s', 'IN_TEST_HARNESS=1', '-DEMTEST_PORT_NUMBER=%d' % self.port,
-             '-I', path_from_root('tests'),
-             '-include', path_from_root('tests', 'report_result.h'),
-             path_from_root('tests', 'report_result.cpp')]
-    self.run_process([EMCC] + args + ['--pre-js', path_from_root('tests', 'browser_reporting.js')])
+    args += ['-s', 'IN_TEST_HARNESS=1']
+    if reporting:
+      args += ['-DEMTEST_PORT_NUMBER=%d' % self.port,
+               '-I', path_from_root('tests'),
+               '-include', path_from_root('tests', 'report_result.h'),
+               path_from_root('tests', 'report_result.cpp'),
+               '--pre-js', path_from_root('tests', 'browser_reporting.js')]
+    self.run_process([EMCC] + args)
 
   def btest(self, filename, expected=None, reference=None, force_c=False,
             reference_slack=0, manual_reference=False, post_build=None,
             args=None, message='.', also_proxied=False,
             url_suffix='', timeout=None, also_asmjs=False,
-            manually_trigger_reftest=False, extra_tries=1):
+            manually_trigger_reftest=False, extra_tries=1,
+            reporting=True):
     assert expected or reference, 'a btest must either expect an output, or have a reference image'
     if args is None:
       args = []
@@ -1523,7 +1527,7 @@ def btest(self, filename, expected=None, reference=None, force_c=False,
     args = [filepath, '-o', outfile] + args
     # print('all args:', args)
     try_delete(outfile)
-    self.compile_btest(args)
+    self.compile_btest(args, reporting)
     self.assertExists(outfile)
     if post_build:
       post_build()

tests/test_browser.py

@@ -2400,15 +2400,17 @@ def test_runtime_misuse(self):
     ]:
       for mode in [[], ['-s', 'WASM=0']]:
         print('\n', filename, extra_args, mode)
+
         print('mem init, so async, call too early')
         create_test_file('post.js', post_prep + post_test + post_hook)
-        self.btest(filename, expected='600', args=['--post-js', 'post.js', '--memory-init-file', '1', '-s', 'EXIT_RUNTIME=1'] + extra_args + mode)
+        self.btest(filename, expected='600', args=['--post-js', 'post.js', '--memory-init-file', '1', '-s', 'EXIT_RUNTIME=1'] + extra_args + mode, reporting=False)
         print('sync startup, call too late')
         create_test_file('post.js', post_prep + 'Module.postRun.push(function() { ' + post_test + ' });' + post_hook)
-        self.btest(filename, expected=str(second_code), args=['--post-js', 'post.js', '-s', 'EXIT_RUNTIME=1'] + extra_args + mode)
+        self.btest(filename, expected=str(second_code), args=['--post-js', 'post.js', '-s', 'EXIT_RUNTIME=1'] + extra_args + mode, reporting=False)
+
         print('sync, runtime still alive, so all good')
         create_test_file('post.js', post_prep + 'expected_ok = true; Module.postRun.push(function() { ' + post_test + ' });' + post_hook)
-        self.btest(filename, expected='606', args=['--post-js', 'post.js'] + extra_args + mode)
+        self.btest(filename, expected='606', args=['--post-js', 'post.js'] + extra_args + mode, reporting=False)
 
   def test_cwrap_early(self):
     self.btest(os.path.join('browser', 'cwrap_early.cpp'), args=['-O2', '-s', 'ASSERTIONS=1', '--pre-js', path_from_root('tests', 'browser', 'cwrap_early.js'), '-s', 'EXTRA_EXPORTED_RUNTIME_METHODS=["cwrap"]'], expected='0')
@@ -4539,14 +4541,13 @@ def test_base64_atob_fallback(self):
       #include <stdio.h>
       #include <emscripten.h>
       int main() {
-        REPORT_RESULT(0);
         return 0;
       }
     ''')
     # generate a dummy file
     create_test_file('dummy_file', 'dummy')
     # compile the code with the modularize feature and the preload-file option enabled
-    self.compile_btest(['test.c', '-s', 'MODULARIZE=1', '-s', 'EXPORT_NAME="Foo"', '--preload-file', 'dummy_file', '-s', 'SINGLE_FILE=1'])
+    self.compile_btest(['test.c', '-s', 'EXIT_RUNTIME', '-s', 'MODULARIZE=1', '-s', 'EXPORT_NAME="Foo"', '--preload-file', 'dummy_file', '-s', 'SINGLE_FILE=1'])
     create_test_file('a.html', '''
       <script>
         atob = undefined;
@@ -4557,7 +4558,7 @@ def test_base64_atob_fallback(self):
         var foo = Foo();
       </script>
     ''')
-    self.run_browser('a.html', '...', '/report_result?0')
+    self.run_browser('a.html', '...', '/report_result?exit:0')
 
   # Tests that SINGLE_FILE works as intended in generated HTML (with and without Worker)
   def test_single_file_html(self):