Add flag contradictions for ClusterFuzz and a README

Add flag contradictions for "assert-types" flag and a README file for how
to add trials from the source side. Also restore "assert-types" and its
contradictions' probability since we can avoid contradictions now.

Bug: v8:1340816,v8:1336577
No-Try: true
Change-Id: I2a3af2d13cd2f9f542bec5c013c50bf26ff93cc1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3787878
Commit-Queue: Almothana Athamneh <almuthanna@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82133}

tools/clusterfuzz/trials/PRESUBMIT.py

@@ -21,10 +21,15 @@ def _CheckTrialsConfig(input_api, output_api):
     with open(f.AbsoluteLocalPath()) as j:
       try:
         trials = json.load(j)
+        mandatory_properties = {'app_args', 'app_name', 'probability'}
+        optional_properties = {'contradicts'}
+        all_properties = mandatory_properties.union(optional_properties)
         for trial in trials:
-          if not all(
-              k in trial for k in ('app_args', 'app_name', 'probability')):
-            results.append('trial {} is not configured correctly'.format(trial))
+          trial_keys = set(trial.keys())
+          if not mandatory_properties.issubset(trial_keys):
+            results.append('trial {} does not have mandatory propertie(s) {}'.format(trial, mandatory_properties - trial_keys))
+          if not trial_keys.issubset(all_properties):
+            results.append('trial {} has incorrect propertie(s) {}'.format(trial, trial_keys - all_properties))
           if trial['app_name'] != 'd8':
             results.append('trial {} has an incorrect app_name'.format(trial))
           if not isinstance(trial['probability'], float):
@@ -36,6 +41,11 @@ def _CheckTrialsConfig(input_api, output_api):
             results.append(
                 'trial {} should have a non-empty string for app_args'.format(
                     trial))
+          contradicts = trial.get('contradicts', [])
+          if not isinstance(contradicts, list) or not all(
+              isinstance(cont, str) for cont in contradicts):
+              results.append(
+                'trial {} contradicts is not a list of strings'.format(trial))
       except Exception as e:
         results.append(
             'JSON validation failed for %s. Error:\n%s' % (f.LocalPath(), e))

tools/clusterfuzz/trials/README.md

+It is possible to add trials from the source code side by adding the below line
+to `clusterfuzz_trials_config.json`:
+
+```
+{
+  "app_args": "FLAG_NAME",
+  "app_name": "APP_NAME",
+  "probability": PROBABILITY,
+  "contradicts": ["FLAG1", "FLAG2", ...]
+}
+```
+
+- `app_args`: the name of the flag we want to add.
+- `app_name`: the name of the app we are adding the flag for, this must be `d8` on `V8`.
+- `probability`: the probability of this flag to be selected.
+- `contradicts` (optional): the flags that contradict the flag referred to in `app_args`.
+This will stop flags that contradict each other from being added in the same
+trial.

tools/clusterfuzz/trials/clusterfuzz_trials_config.json

 [
-    {"app_args": "--assert-types", "app_name": "d8", "probability": 0.10},
+    {"app_args": "--assert-types", "app_name": "d8", "probability": 0.25, "contradicts": ["--stress-concurrent-inlining", "--stress-concurrent-inlining-attach-code"]},
     {"app_args": "--interrupt-budget-for-feedback-vector-allocation=0", "app_name": "d8", "probability": 0.05},
     {"app_args": "--compact-maps", "app_name": "d8", "probability": 0.25},
     {"app_args": "--force-slow-path", "app_name": "d8", "probability": 0.05},
@@ -28,8 +28,8 @@
     {"app_args": "--regexp-interpret-all", "app_name": "d8", "probability": 0.1},
     {"app_args": "--simulate-errors", "app_name": "d8", "probability": 0.001},
     {"app_args": "--stress-compaction-random", "app_name": "d8", "probability": 0.05},
-    {"app_args": "--stress-concurrent-inlining", "app_name": "d8", "probability": 0.10},
-    {"app_args": "--stress-concurrent-inlining-attach-code", "app_name": "d8", "probability": 0.10},
+    {"app_args": "--stress-concurrent-inlining", "app_name": "d8", "probability": 0.25, "contradicts": ["--assert-types"]},
+    {"app_args": "--stress-concurrent-inlining-attach-code", "app_name": "d8", "probability": 0.25, "contradicts": ["--assert-types"]},
     {"app_args": "--stress-flush-code", "app_name": "d8", "probability": 0.25},
     {"app_args": "--stress-marking=100", "app_name": "d8", "probability": 0.05},
     {"app_args": "--stress-scavenge=100", "app_name": "d8", "probability": 0.05},