Add anyref feature and type (#3109)

Adds `anyref` type, which is enabled by a new feature `--enable-anyref`. This type is primarily used for testing that passes correctly handle subtype relationships so that the codebase will continue to be prepared for future subtyping. Since `--enable-anyref` is meaningless without also using `--enable-reference-types`, this PR also makes it a validation error to pass only the former (and similarly makes it a validation error to enable exception handling without enabling reference types).

1 files changed, 12 insertions, 4 deletions

diff --git a/scripts/fuzz_opt.py b/scripts/fuzz_opt.py
index bf1f7f409..4df552b99 100755
--- a/scripts/fuzz_opt.py
+++ b/scripts/fuzz_opt.py
@@ -111,6 +111,8 @@ def randomize_feature_opts():
         for possible in POSSIBLE_FEATURE_OPTS:
             if random.random() < 0.5:
                 FEATURE_OPTS.append(possible)
+                if possible in IMPLIED_FEATURE_OPTS:
+                    FEATURE_OPTS.extend(IMPLIED_FEATURE_OPTS[possible])
     print('randomized feature opts:', ' '.join(FEATURE_OPTS))
 
 
@@ -402,7 +404,7 @@ class CompareVMs(TestCaseHandler):
                 if random.random() < 0.5:
                     return False
                 # wasm2c doesn't support most features
-                return all([x in FEATURE_OPTS for x in ['--disable-exception-handling', '--disable-simd', '--disable-threads', '--disable-bulk-memory', '--disable-nontrapping-float-to-int', '--disable-tail-call', '--disable-sign-ext', '--disable-reference-types', '--disable-multivalue']])
+                return all([x in FEATURE_OPTS for x in ['--disable-exception-handling', '--disable-simd', '--disable-threads', '--disable-bulk-memory', '--disable-nontrapping-float-to-int', '--disable-tail-call', '--disable-sign-ext', '--disable-reference-types', '--disable-multivalue', '--disable-anyref']])
 
             def run(self, wasm):
                 run([in_bin('wasm-opt'), wasm, '--emit-wasm2c-wrapper=main.c'] + FEATURE_OPTS)
@@ -502,7 +504,7 @@ class CompareVMs(TestCaseHandler):
                 compare(before[vm], after[vm], 'CompareVMs between before and after: ' + vm.name)
 
     def can_run_on_feature_opts(self, feature_opts):
-        return all([x in feature_opts for x in ['--disable-simd', '--disable-reference-types', '--disable-exception-handling', '--disable-multivalue']])
+        return all([x in feature_opts for x in ['--disable-simd', '--disable-reference-types', '--disable-exception-handling', '--disable-multivalue', '--disable-anyref']])
 
 
 # Check for determinism - the same command must have the same output.
@@ -633,7 +635,7 @@ class Wasm2JS(TestCaseHandler):
         return run_vm([shared.NODEJS, js_file, 'a.wasm'])
 
     def can_run_on_feature_opts(self, feature_opts):
-        return all([x in feature_opts for x in ['--disable-exception-handling', '--disable-simd', '--disable-threads', '--disable-bulk-memory', '--disable-nontrapping-float-to-int', '--disable-tail-call', '--disable-sign-ext', '--disable-reference-types', '--disable-multivalue']])
+        return all([x in feature_opts for x in ['--disable-exception-handling', '--disable-simd', '--disable-threads', '--disable-bulk-memory', '--disable-nontrapping-float-to-int', '--disable-tail-call', '--disable-sign-ext', '--disable-reference-types', '--disable-multivalue', '--disable-anyref']])
 
 
 class Asyncify(TestCaseHandler):
@@ -687,7 +689,7 @@ class Asyncify(TestCaseHandler):
         compare(before, after_asyncify, 'Asyncify (before/after_asyncify)')
 
     def can_run_on_feature_opts(self, feature_opts):
-        return all([x in feature_opts for x in ['--disable-exception-handling', '--disable-simd', '--disable-tail-call', '--disable-reference-types', '--disable-multivalue']])
+        return all([x in feature_opts for x in ['--disable-exception-handling', '--disable-simd', '--disable-tail-call', '--disable-reference-types', '--disable-multivalue', '--disable-anyref']])
 
 
 # The global list of all test case handlers
@@ -870,6 +872,12 @@ def randomize_opt_flags():
 POSSIBLE_FEATURE_OPTS = run([in_bin('wasm-opt'), '--print-features', in_binaryen('test', 'hello_world.wat')] + CONSTANT_FEATURE_OPTS).replace('--enable', '--disable').strip().split('\n')
 print('POSSIBLE_FEATURE_OPTS:', POSSIBLE_FEATURE_OPTS)
 
+# some features depend on other features, so if a required feature is
+# disabled, its dependent features need to be disabled as well.
+IMPLIED_FEATURE_OPTS = {
+    '--disable-reference-types': ['--disable-exception-handling', '--disable-anyref']
+}
+
 if __name__ == '__main__':
     # if we are given a seed, run exactly that one testcase. otherwise,
     # run new ones until we fail