From fe08c991c508a77f14b4bb243c90da106f7d7e71 Mon Sep 17 00:00:00 2001 From: Drew Scoggins Date: Thu, 2 Jul 2026 09:59:28 -0700 Subject: [PATCH] Revert "[wasm] Pass --experimental-wasm-exnref to V8 for perf runs (#5247)" This reverts commit 4fe479c5975bb932cfd35c2f6d565b32cd9dc51b. The flag is not needed and does nothing useful. Per dotnet/runtime#129849 (Failure 3, the wasm-perf leg), the perf leg resolves its V8 engine solely from runtime's eng/testing/BrowserVersions.props (linux_V8Version) via jsvu; no dotnet/performance change is required. Verified directly against real d8 15.1.103 on both win32 and linux64 (the platform jsvu installs on Helix): the runtime's own gate -- wasm-feature-detect 1.8.0 exceptionsFinal() probe used by startup.ts -- returns SUPPORTED, so the engine already ships exnref by default. --experimental-wasm-exnref does not exist in V8 15.1 and is reported as an "unknown flag" (harmless, but noise). The authoritative fix is the BrowserVersions.props V8 bump to an exnref-capable build (15.1.103), which has already landed. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- scripts/run_performance_job.py | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/scripts/run_performance_job.py b/scripts/run_performance_job.py index dabe5cb05d5..0904e70a771 100644 --- a/scripts/run_performance_job.py +++ b/scripts/run_performance_job.py @@ -443,12 +443,6 @@ def get_bdn_arguments( "--wasmProcessTimeout", "20", ] - # The runtime now uses the standardized exnref WASM exception-handling proposal, - # which V8 keeps behind --experimental-wasm-exnref. Pass it through to the engine - # via BDN's --wasmArgs (the escaped quotes keep it a single token on the Helix shell). - if javascript_engine == "v8": - bdn_arguments += ["\\\"--wasmArgs=--experimental-wasm-exnref\\\""] - if is_aot: bdn_arguments += [ "--aotcompilermode", "wasm", @@ -466,12 +460,6 @@ def get_bdn_arguments( "--wasmProcessTimeout", "20" ] - # The runtime now uses the standardized exnref WASM exception-handling proposal, - # which V8 keeps behind --experimental-wasm-exnref. Pass it through to the engine - # via BDN's --wasmArgs (the escaped quotes keep it a single token on the Helix shell). - if javascript_engine == "v8": - bdn_arguments += ["\\\"--wasmArgs=--experimental-wasm-exnref\\\""] - if runtime_type == "coreclr_r2r_interpreter": if os_group == "windows": bdn_arguments += [