Do not fuzz on V8 with custom descriptors enabled (#7351)

V8 does not yet support custom descriptors, so update all fuzz handlers
that use it to avoid running when the feature is enabled. Since running
V8 is important, though, disable the feature most of the time, just like
we do for shared-everything.

Author: tlively

scripts/bundle_clusterfuzz.py

@@ -106,6 +106,7 @@
     '-all',
     '--disable-shared-everything',
     '--disable-fp16',
+    '--disable-custom-descriptors',
 ]
 
 with tarfile.open(output_file, "w:gz") as tar:

scripts/clusterfuzz/run.py

@@ -87,6 +87,7 @@
     '-all',
     '--disable-shared-everything',
     '--disable-fp16',
+    '--disable-custom-descriptors',
 ]
 
 

scripts/fuzz_opt.py

@@ -151,8 +151,10 @@ def randomize_feature_opts():
 
         # The shared-everything feature is new and we want to fuzz it, but it
         # also currently disables fuzzing V8, so disable it most of the time.
+        # Same with custom descriptors.
         if random.random() < 0.9:
             FEATURE_OPTS.append('--disable-shared-everything')
+            FEATURE_OPTS.append('--disable-custom-descriptors')
 
     print('randomized feature opts:', '\n  ' + '\n  '.join(FEATURE_OPTS))
 
@@ -813,8 +815,8 @@ def run(self, wasm, extra_d8_flags=[]):
             def can_run(self, wasm):
                 # V8 does not support shared memories when running with
                 # shared-everything enabled, so do not fuzz shared-everything
-                # for now.
-                return all_disallowed(['shared-everything'])
+                # for now. It also does not yet support custom descriptors.
+                return all_disallowed(['shared-everything', 'custom-descriptors'])
 
             def can_compare_to_self(self):
                 # With nans, VM differences can confuse us, so only very simple VMs
@@ -864,7 +866,7 @@ def can_run(self, wasm):
                 if random.random() < 0.5:
                     return False
                 # wasm2c doesn't support most features
-                return all_disallowed(['exception-handling', 'simd', 'threads', 'bulk-memory', 'nontrapping-float-to-int', 'tail-call', 'sign-ext', 'reference-types', 'multivalue', 'gc'])
+                return all_disallowed(['exception-handling', 'simd', 'threads', 'bulk-memory', 'nontrapping-float-to-int', 'tail-call', 'sign-ext', 'reference-types', 'multivalue', 'gc', 'custom-descriptors'])
 
             def run(self, wasm):
                 run([in_bin('wasm-opt'), wasm, '--emit-wasm2c-wrapper=main.c'] + FEATURE_OPTS)
@@ -1165,7 +1167,7 @@ def can_run_on_wasm(self, wasm):
         # implement wasm suspending using JS async/await.
         if JSPI:
             return False
-        return all_disallowed(['exception-handling', 'simd', 'threads', 'bulk-memory', 'nontrapping-float-to-int', 'tail-call', 'sign-ext', 'reference-types', 'multivalue', 'gc', 'multimemory', 'memory64'])
+        return all_disallowed(['exception-handling', 'simd', 'threads', 'bulk-memory', 'nontrapping-float-to-int', 'tail-call', 'sign-ext', 'reference-types', 'multivalue', 'gc', 'multimemory', 'memory64', 'custom-descriptors'])
 
 
 # given a wasm, find all the exports of particular kinds (for example, kinds
@@ -1571,7 +1573,7 @@ def can_run_on_wasm(self, wasm):
             return False
 
         # see D8.can_run
-        return all_disallowed(['shared-everything'])
+        return all_disallowed(['shared-everything', 'custom-descriptors'])
 
 
 # Check that the text format round-trips without error.
@@ -1752,7 +1754,11 @@ def can_run_on_wasm(self, wasm):
         # mode. We also cannot run shared-everything code in d8 yet. We also
         # cannot compare if there are NaNs (as optimizations can lead to
         # different outputs).
-        return not CLOSED_WORLD and all_disallowed(['shared-everything']) and not NANS
+        if CLOSED_WORLD:
+            return False
+        if NANS:
+            return False
+        return all_disallowed(['shared-everything', 'custom-descriptors'])
 
 
 # Test --fuzz-preserve-imports-exports, which never modifies imports or exports.