diff options
Diffstat (limited to 'scripts/fuzz_opt.py')
| -rwxr-xr-x | scripts/fuzz_opt.py | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/scripts/fuzz_opt.py b/scripts/fuzz_opt.py index 7522dce8c..bf712c821 100755 --- a/scripts/fuzz_opt.py +++ b/scripts/fuzz_opt.py @@ -1230,6 +1230,16 @@ def filter_exports(wasm, output, keep, keep_defaults=True): run([in_bin('wasm-metadce'), wasm, '-o', output, '--graph-file', 'graph.json'] + FEATURE_OPTS) +# Check if a wasm file would notice changes to exports. Normally removing an +# export that is not called, for example, would not be observable, but if the +# "call-export*" functions are present then such changes can break us. +def wasm_notices_export_changes(wasm): + # we could be more precise here and disassemble the wasm to look for an + # actual import with name "call-export*", but looking for the string should + # have practically no false positives. + return b'call-export' in open(wasm, 'rb').read() + + # Fuzz the interpreter with --fuzz-exec -tnh. The tricky thing with traps-never- # happen mode is that if a trap *does* happen then that is undefined behavior, # and the optimizer was free to make changes to observable behavior there. The @@ -1323,6 +1333,12 @@ class TrapsNeverHappen(TestCaseHandler): compare_between_vms(before, after, 'TrapsNeverHappen') + def can_run_on_wasm(self, wasm): + # If the wasm is sensitive to changes in exports then we cannot alter + # them, but we must remove trapping exports (see above), so we cannot + # run in such a case. + return not wasm_notices_export_changes(wasm) + # Tests wasm-ctor-eval class CtorEval(TestCaseHandler): @@ -1354,6 +1370,12 @@ class CtorEval(TestCaseHandler): compare_between_vms(fix_output(wasm_exec), fix_output(evalled_wasm_exec), 'CtorEval') + def can_run_on_wasm(self, wasm): + # ctor-eval modifies exports, because it assumes they are ctors and so + # are only called once (so if it evals them away, they can be + # removed). If the wasm might notice that, we cannot run. + return not wasm_notices_export_changes(wasm) + # Tests wasm-merge class Merge(TestCaseHandler): @@ -1427,6 +1449,12 @@ class Merge(TestCaseHandler): compare_between_vms(output, merged_output, 'Merge') + def can_run_on_wasm(self, wasm): + # wasm-merge combines exports, which can alter their indexes and lead to + # noticeable differences if the wasm is sensitive to such things, which + # prevents us from running. + return not wasm_notices_export_changes(wasm) + FUNC_NAMES_REGEX = re.compile(r'\n [(]func [$](\S+)') |