Run more of out tests with -sNO_DEFAULT_TO_CXX

We were previously only applying this flag to tests that use
`self.build` (i.e. most test).  Now we apply it to and even larger set.

The code size changes here only occur in debug builds where we enumerate
all known JS symbols, and there are come JS symbols are the C++ only.

Author: sbc100

test/common.py

@@ -833,6 +833,11 @@ def setUp(self):
     self.js_engines = config.JS_ENGINES.copy()
     self.settings_mods = {}
     self.emcc_args = ['-Wclosure', '-Werror', '-Wno-limited-postlink-optimizations']
+    # TODO(https://github.com/emscripten-core/emscripten/issues/11121)
+    # For historical reasons emcc compiles and links as C++ by default.
+    # However we want to run our tests in a more strict manner.  We can
+    # remove this if the issue above is ever fixed.
+    self.set_setting('NO_DEFAULT_TO_CXX')
     self.ldflags = []
     # Increate stack trace limit to maximise usefulness of test failure reports
     self.node_args = ['--stack-trace-limit=50']
@@ -954,9 +959,13 @@ def has_changed_setting(self, key):
   def clear_setting(self, key):
     self.settings_mods.pop(key, None)
 
-  def serialize_settings(self):
+  def serialize_settings(self, ldflags=True):
     ret = []
+    # Incomplete list of link-only settings
+    link_only_settings = ['NO_DEFAULT_TO_CXX']
     for key, value in self.settings_mods.items():
+      if not ldflags and key in link_only_settings:
+        continue
       if value == 1:
         ret.append(f'-s{key}')
       elif type(value) is list:
@@ -994,7 +1003,7 @@ def get_emcc_args(self, main_file=False, ldflags=True):
     def is_ldflag(f):
       return any(f.startswith(s) for s in ['-sENVIRONMENT=', '--pre-js=', '--post-js='])
 
-    args = self.serialize_settings() + self.emcc_args
+    args = self.serialize_settings(ldflags) + self.emcc_args
     if ldflags:
       args += self.ldflags
     else:
@@ -1034,12 +1043,6 @@ def build(self, filename, libraries=None, includes=None, force_c=False, js_outfi
       filename = test_file(filename)
     suffix = '.js' if js_outfile else '.wasm'
     compiler = [compiler_for(filename, force_c)]
-    if compiler[0] == EMCC:
-      # TODO(https://github.com/emscripten-core/emscripten/issues/11121)
-      # For historical reasons emcc compiles and links as C++ by default.
-      # However we want to run our tests in a more strict manner.  We can
-      # remove this if the issue above is ever fixed.
-      compiler.append('-sNO_DEFAULT_TO_CXX')
 
     if force_c:
       assert shared.suffix(filename) != '.c', 'force_c is not needed for source files ending in .c'
@@ -2106,7 +2109,7 @@ def reftest(self, expected, manually_trigger=False):
       setupRefTest();
 ''' % (reporting, basename, int(manually_trigger)))
 
-  def compile_btest(self, args, reporting=Reporting.FULL):
+  def compile_btest(self, args, reporting=Reporting.FULL, compiler=EMCC):
     # Inject support code 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
@@ -2123,7 +2126,7 @@ def compile_btest(self, args, reporting=Reporting.FULL):
                  test_file('report_result.c')]
     if EMTEST_BROWSER == 'node':
       args.append('-DEMTEST_NODE')
-    self.run_process([EMCC] + self.get_emcc_args() + args)
+    self.run_process([compiler] + self.get_emcc_args() + args)
 
   def btest_exit(self, filename, assert_returncode=0, *args, **kwargs):
     """Special case of btest that reports its result solely via exiting
@@ -2169,7 +2172,7 @@ def btest(self, filename, expected=None, reference=None,
     args += [filename, '-o', outfile]
     # print('all args:', args)
     utils.delete_file(outfile)
-    self.compile_btest(args, reporting=reporting)
+    self.compile_btest(args, reporting=reporting, compiler=compiler_for(filename))
     self.assertExists(outfile)
     if post_build:
       post_build()

test/other/metadce/test_metadce_hello_O0.gzsize

@@ -1 +1 @@
-8420
+8389

test/other/metadce/test_metadce_hello_O0.jssize

@@ -1 +1 @@
-23089
+23004

test/other/metadce/test_metadce_minimal_O0.gzsize

@@ -1 +1 @@
-7250
+7217

test/other/metadce/test_metadce_minimal_O0.jssize

@@ -1 +1 @@
-19713
+19628

test/test_other.py

@@ -3108,7 +3108,7 @@ def test_embind_tsgen_val(self):
     self.assertExists('embind_tsgen_val.d.ts')
 
   def test_embind_tsgen_bigint(self):
-    args = [EMCC, test_file('other/embind_tsgen_bigint.cpp'), '-lembind', '--embind-emit-tsd', 'embind_tsgen_bigint.d.ts']
+    args = [EMXX, test_file('other/embind_tsgen_bigint.cpp'), '-lembind', '--embind-emit-tsd', 'embind_tsgen_bigint.d.ts']
     # Check that TypeScript generation fails when code contains bigints but their support is not enabled
     stderr = self.expect_fail(args)
     self.assertContained("Missing primitive type to TS type for 'int64_t", stderr)
@@ -3118,14 +3118,14 @@ def test_embind_tsgen_bigint(self):
 
   def test_embind_tsgen_memory64(self):
     # Check that when memory64 is enabled longs & unsigned longs are mapped to bigint in the generated TS bindings
-    self.run_process([EMCC, test_file('other/embind_tsgen_memory64.cpp'),
+    self.run_process([EMXX, test_file('other/embind_tsgen_memory64.cpp'),
                       '-lembind', '--embind-emit-tsd', 'embind_tsgen_memory64.d.ts', '-sMEMORY64', '-Wno-experimental'] +
                      self.get_emcc_args())
     self.assertFileContents(test_file('other/embind_tsgen_memory64.d.ts'), read_file('embind_tsgen_memory64.d.ts'))
 
   def test_embind_tsgen_exceptions(self):
     # Check that when Wasm exceptions and assertions are enabled bindings still generate.
-    self.run_process([EMCC, test_file('other/embind_tsgen.cpp'),
+    self.run_process([EMXX, test_file('other/embind_tsgen.cpp'),
                       '-lembind', '--embind-emit-tsd', 'embind_tsgen.d.ts', '-fwasm-exceptions', '-sASSERTIONS'])
     self.assertFileContents(test_file('other/embind_tsgen.d.ts'), read_file('embind_tsgen.d.ts'))