[v22.x] deps: V8: backport Wasm exception handling correctness fixes by guybedford · Pull Request #62783 · nodejs/node · GitHub

This is a set of V8 backports that land correctness fixes for the modern WebAssembly exception handling (exnref / try_table / throw_ref) implementation in Node.js 22's V8 12.4.254.21.

Node.js 22 force-enables --experimental-wasm-exnref at startup via src/node.cc, so the modern Wasm EH code paths are reachable by any Wasm module shipped by Node 22 users — including the default try_table / throw_ref sequences emitted by current toolchains (LLVM/Emscripten with -fwasm-exceptions, wasm-bindgen, AssemblyScript exception mode, etc.).

V8 12.4's exnref implementation predates spec finalization (April 2025) and has known correctness bugs that manifest as runtime traps (RuntimeError: unreachable inside catch wrappers), validation errors on spec-conforming modules, wrong representation of null exnref, and mis-canonicalization of exception tags across instances.

This PR brings in the strict-correctness subset of upstream V8's exnref fixes from 12.4.254.21..main, ordered chronologically to respect dependency order. Every commit is a focused correctness fix; refactors, DCHECK-only changes, Turboshaft-specific fixes (Node 22 uses Turbofan for Wasm), JSPI-specific fixes, and fuzzer-only hardening have been deliberately excluded.

#	SHA	Subject
1	5f1342c20b59	[wasm][exnref] Fix broken abstract casts
2	b2f3aea23a01	[wasm][exnref] Do not allow exnref at wasm/JS boundary
3	c734674e03f9	[wasm][exnref] Fix null value for constant expressions
4	692f3d526a38	[wasm][exnref] Special behavior of WA.JSTag in try_table
5	cf03d55db2a0	[wasm][exnref] Fix default value for null exnref
6	b8f91e510e0f	[wasm][exnref] Update WA.JSTag semantics
7	910cb91733dc	[wasm][liftoff][arm64] Fix DropExceptionValueAtOffset
8	89dc6eab605c	[wasm] Add missing type canonicalization for exceptions JS API
9	323942700cfe	[wasm][exnref] Accept exnref subtypes for throw_ref
10	63b8849d73ae	[wasm][exnref] Reject non-nullable exnref in JS import/export
11	8e214ec3ec8c	[wasm][exnref] Fix catchless try_table
12	e7ccf0af1bdd	[wasm] Fix default externref/exnref reference
13	7cb6188cf913	[wasm][exnref] Accept non-nullable exn catch type
14	b96e40d5ac85	[wasm][js-api] Fix exception handling in WebAssembly.Exception ctor
15	9997fc013952	[wasm][exnref] Use wasm_null for exnref (null representation fix)
16	1b27e4674f11	[wasm] Disallow v128 in exception handling JS API
17	85b390089e51	[wasm][eh] Fix getArg() when exception has an S128

Notable

Commit #4 (692f3d526a38) in particular fixes a runtime RuntimeError: unreachable thrown from within the try_table JSTag catch wrapper on v22.x — the most user-visible symptom that motivated this triage.

Commit #15 (9997fc013952) changes the internal representation of a null exnref to use V8's wasm_null sentinel so that throw_ref of a caught JS null vs. a null exnref can behave per the spec (one rethrowable, one not). The upstream patch adds a use_wasm_null() helper; in this backport the equivalent representation change has been applied directly to the three compilers (Liftoff / Turbofan / graph-builder-interface) and the constant-expression interface, since the helper doesn't exist in V8 12.4. The new WasmThrowRef builtin from the upstream patch is included verbatim.

Commits #8 (89dc6eab605c) and #15 required manual porting because of V8 API drift; all others applied with git node v8 backport either cleanly or with only line-offset fuzz.

Explicitly NOT included

Per the Node.js V8 maintenance policy ("Only bug fixes are accepted for backporting") and scoping to observable user-facing correctness, the following upstream commits were excluded:

Turboshaft-only fixes (Turboshaft for Wasm is not the default optimizer in V8 12.4)
JSPI-specific fixes (--experimental-wasm-jspi is not forced on in Node 22)
DCHECK-only fixes (no release-build impact)
Fuzzer-only hardening of %GetWasmExceptionTag* intrinsics (require --allow-natives-syntax)
The 737-line WasmJSApiScope refactor (7d4ba5062ac) and its follow-ups — error-message consistency, not correctness
wasm_null helper follow-ups (47fb21842c1) — superseded by the direct application in commit domain: add arguments for the function in domain.run() #15
[wasm][eh] mixed old/new EH disabling (af887e07511 / bf0970ea9e5) — spec conformance rather than a crash/miscompile
5e3f70eb5b9 (Liftoff slot count for EH) — a legacy-EH bug, being tracked as a separate backport concern
2d499b85959 (top type) — compiler-hardening, not user-facing correctness

A final omission worth calling out: 657d8de2742 [maglev] Fix throwing node inside eager inlining — the single most impactful remaining wasm-EH correctness fix upstream. This one applies equally to Node 22 and Node 24 and will be submitted as a separate PR so it can be released in parallel with this series.

Verification

make -j$(nproc) completes cleanly against v22.x-staging.
Binary reports v22.22.3-pre / V8 12.4.254.21-node.40.
WebAssembly EH JS APIs (WebAssembly.Tag, WebAssembly.Exception) present and functional.
Wasm Bindgen panic=unwind test suite passes with this change
The V8 CI run (node-test-commit-v8-linux) should be requested in addition to the regular CI per the Node.js V8 maintenance doc.

/cc @nodejs/v8 @nodejs/lts @nodejs/releasers

Original commit message: [wasm][exnref] Fix broken abstract casts ref.test, ref.cast, br_on_cast, br_on_cast_fail allow arbitrary heap types, so they also allow exnref and noexnref. This CL also fixes the missing type checks in the js to wasm wrapper. Bug: v8:14398 Change-Id: Ieefb9a8e99d3d7a4b175db60f55b7fa9a96c5203 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5372489 Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Commit-Queue: Matthias Liedtke <mliedtke@chromium.org> Cr-Commit-Position: refs/heads/main@{#92867} Refs: v8/v8@5f1342c

Review requested:

@nodejs/gyp
@nodejs/security-wg
@nodejs/v8-update

CI: https://ci.nodejs.org/job/node-test-pull-request/72730/

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=benchmark-ubuntu2404-intel-64,v8test=v8test/7127/

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-power9le,v8test=v8test/7127/

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-s390x,v8test=v8test/7127/

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-ppc64le,v8test=v8test/7127/

Original commit message: [wasm][exnref] Do not allow exnref at the wasm/JS boundary R=mliedtke@chromium.org Bug: v8:14398 Change-Id: I5bb75a83e9de9f838d8e530c77c89aa031f473f9 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5381603 Reviewed-by: Matthias Liedtke <mliedtke@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#92944} Refs: v8/v8@b2f3aea

Original commit message: [wasm][exnref] Fix null value for constant expressions Bug: v8:14398 Change-Id: Ia00d2de97a897d608d6c043b6e267c7d6313a18b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5402583 Auto-Submit: Manos Koukoutos <manoskouk@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93107} Refs: v8/v8@c734674

Original commit message: [wasm][exnref] Implement special behavior of WA.JSTag in try_table. This commit ports the changes from 4e79015dc28659a8a031f06580e902720b35674c to `CatchCase`, i.e., the `try_table` instruction. In addition, it implements the same changes in Turboshaft, for which the implementation of exceptions initially came from 2c1c14d30c61fa4fa19184369e587cb663bd8580 and already contained the `JSTag` handling for `CatchException`. This commit addresses part of https://issues.chromium.org/issues/333067164 but not all. Only catching with `try_table` is fixed. `throw` remains unchanged. Change-Id: I7bad031e28eaf609fb12e7706d0b6a7cc63fa09d Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5435077 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93303} Refs: v8/v8@692f3d5

Original commit message: [wasm][exnref] Fix default value for null exnref R=manoskouk@chromium.org Bug: 332081797 Change-Id: Ied777935946c880a78e2011040a4d9ab19a4ddd2 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5444544 Reviewed-by: Manos Koukoutos <manoskouk@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93310} Refs: v8/v8@cf03d55

Original commit message: [wasm][exnref] Update WA.JSTag semantics According to the last spec updates: - Passing WebAssembly.JSTag to the WebAssembly.Exception constructor is not allowed in JS, - Throwing an exception with the JSTag in wasm is allowed, but the exception should conceptually be "unwrapped" when it exits wasm, and JS should observe the raw externref. Instead, we simply throw the externref in this case, which has the same observable behavior and is consistent with how JSTag has been implemented so far. R=ahaas@chromium.org Bug: 333067164 Change-Id: I6f43df8d254dd7450137d99ff7cc9cbffb697663 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5454404 Reviewed-by: Andreas Haas <ahaas@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93398} Refs: v8/v8@b8f91e5

Original commit message: [wasm][liftoff][arm64] Fix DropExceptionValueAtOffset We cannot exit the iteration early, we must update all entries in the cache state. Fixed: 343748812 Change-Id: I8353acb7bd0edc4b979db92e44d24cb9028fd92b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5596273 Reviewed-by: Clemens Backes <clemensb@chromium.org> Commit-Queue: Clemens Backes <clemensb@chromium.org> Auto-Submit: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#94244} Refs: v8/v8@910cb91733dc

Original commit message: [wasm] Add missing type canonicalization for exceptions JS API When we encode a JS value in a wasm exception, canonicalize the type stored in the tag's signature first. Canonicalize it using the tag's original module by storing the instance on the tag object. R=jkummerow@chromium.org Bug: 346197738 Change-Id: I7575fd79c792d98e4a11c00b466700f0ab82d164 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5613375 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#94335} Refs: v8/v8@89dc6eab605c

Original commit message: [wasm][exnref] Accept exnref subtypes for throw_ref Only accepting a strict exnref type was incorrect in two cases: - the stack-polymorphic case, with the bottom type - a noexn param R=jkummerow@chromium.org Fixed: 332931390 Change-Id: I80c96a7026f2469e6a3ce54344c2d5e617b78be7 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5904414 Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#96387} Refs: v8/v8@323942700cfe

Original commit message: [wasm][exnref] Reject non-nullable exnref in JS import/export R=jkummerow@chromium.org Change-Id: I0ba2deb1a9671d87e76fea7bfe76df9eee56442a Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5920338 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#96489} Refs: v8/v8@63b8849d73ae

Original commit message: [wasm][exnref] Fix catchless try_table If the try_table does not have a catch handler, we don't update the {current_catch_} index or set the {previous_catch} field of the block when we enter it. Therefore also skip the reverse operation when the block ends. R=clemensb@chromium.org Fixed: 372261626 Change-Id: Ib3a23e32f9d0ec153d6a00733d96b52cf040e8bd Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5920086 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Clemens Backes <clemensb@chromium.org> Cr-Commit-Position: refs/heads/main@{#96481} Refs: v8/v8@8e214ec

Original commit message: [wasm] Fix default externref/exnref reference - The default nullexternref should be null instead of undefined - The default exnref/nullexnref should be null instead of wasm_null R=mliedtke@chromium.org Fixed: 372285204,372269618 Change-Id: Id5addce2b196f7ba81aac3c2dd9447a91ed2ce2b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5922878 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Matthias Liedtke <mliedtke@chromium.org> Cr-Commit-Position: refs/heads/main@{#96531} Refs: v8/v8@e7ccf0a

Original commit message: [wasm][exnref] Accept non-nullable exn catch type R=jkummerow@chromium.org Fixed: 373681572 Change-Id: Iecfc86d2ce6592a6f442bc3504ddde58ff236f64 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5938956 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#96637} Refs: v8/v8@7cb6188

Original commit message: [wasm][js-api] Fix exception handling in Exception Calling `Get` on the third argument can throw. If so, return immediately. R=thibaudm@chromium.org Fixed: 372993873 Change-Id: I70ec0d0421833a60151f6bcdc9c386f6ad864256 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5937803 Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Commit-Queue: Clemens Backes <clemensb@chromium.org> Cr-Commit-Position: refs/heads/main@{#96627} Refs: v8/v8@b96e40d

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=benchmark-ubuntu2404-intel-64,v8test=v8test/7134/

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-s390x,v8test=v8test/7134/

V8 CI: https://ci.nodejs.org/job/node-test-commit-v8-linux/nodes=rhel8-ppc64le,v8test=v8test/7134/

CI: https://ci.nodejs.org/job/node-test-pull-request/72993/ 💚

@nodejs/releasers ... looks like this is ready to go. what's the timeframe for another v22.x release?

@nodejs/releasers ... looks like this is ready to go. what's the timeframe for another v22.x release?

Wednesday 13th May

Original commit message: [wasm][exnref] Fix broken abstract casts ref.test, ref.cast, br_on_cast, br_on_cast_fail allow arbitrary heap types, so they also allow exnref and noexnref. This CL also fixes the missing type checks in the js to wasm wrapper. Bug: v8:14398 Change-Id: Ieefb9a8e99d3d7a4b175db60f55b7fa9a96c5203 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5372489 Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Commit-Queue: Matthias Liedtke <mliedtke@chromium.org> Cr-Commit-Position: refs/heads/main@{#92867} Refs: v8/v8@5f1342c PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Do not allow exnref at the wasm/JS boundary R=mliedtke@chromium.org Bug: v8:14398 Change-Id: I5bb75a83e9de9f838d8e530c77c89aa031f473f9 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5381603 Reviewed-by: Matthias Liedtke <mliedtke@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#92944} Refs: v8/v8@b2f3aea PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Fix null value for constant expressions Bug: v8:14398 Change-Id: Ia00d2de97a897d608d6c043b6e267c7d6313a18b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5402583 Auto-Submit: Manos Koukoutos <manoskouk@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93107} Refs: v8/v8@c734674 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Implement special behavior of WA.JSTag in try_table. This commit ports the changes from 4e79015dc28659a8a031f06580e902720b35674c to `CatchCase`, i.e., the `try_table` instruction. In addition, it implements the same changes in Turboshaft, for which the implementation of exceptions initially came from 2c1c14d30c61fa4fa19184369e587cb663bd8580 and already contained the `JSTag` handling for `CatchException`. This commit addresses part of https://issues.chromium.org/issues/333067164 but not all. Only catching with `try_table` is fixed. `throw` remains unchanged. Change-Id: I7bad031e28eaf609fb12e7706d0b6a7cc63fa09d Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5435077 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93303} Refs: v8/v8@692f3d5 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Fix default value for null exnref R=manoskouk@chromium.org Bug: 332081797 Change-Id: Ied777935946c880a78e2011040a4d9ab19a4ddd2 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5444544 Reviewed-by: Manos Koukoutos <manoskouk@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93310} Refs: v8/v8@cf03d55 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Update WA.JSTag semantics According to the last spec updates: - Passing WebAssembly.JSTag to the WebAssembly.Exception constructor is not allowed in JS, - Throwing an exception with the JSTag in wasm is allowed, but the exception should conceptually be "unwrapped" when it exits wasm, and JS should observe the raw externref. Instead, we simply throw the externref in this case, which has the same observable behavior and is consistent with how JSTag has been implemented so far. R=ahaas@chromium.org Bug: 333067164 Change-Id: I6f43df8d254dd7450137d99ff7cc9cbffb697663 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5454404 Reviewed-by: Andreas Haas <ahaas@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#93398} Refs: v8/v8@b8f91e5 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Landed in 005508d...ec11f3c

Original commit message: [wasm][liftoff][arm64] Fix DropExceptionValueAtOffset We cannot exit the iteration early, we must update all entries in the cache state. Fixed: 343748812 Change-Id: I8353acb7bd0edc4b979db92e44d24cb9028fd92b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5596273 Reviewed-by: Clemens Backes <clemensb@chromium.org> Commit-Queue: Clemens Backes <clemensb@chromium.org> Auto-Submit: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#94244} Refs: v8/v8@910cb91733dc PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm] Add missing type canonicalization for exceptions JS API When we encode a JS value in a wasm exception, canonicalize the type stored in the tag's signature first. Canonicalize it using the tag's original module by storing the instance on the tag object. R=jkummerow@chromium.org Bug: 346197738 Change-Id: I7575fd79c792d98e4a11c00b466700f0ab82d164 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5613375 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#94335} Refs: v8/v8@89dc6eab605c PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Accept exnref subtypes for throw_ref Only accepting a strict exnref type was incorrect in two cases: - the stack-polymorphic case, with the bottom type - a noexn param R=jkummerow@chromium.org Fixed: 332931390 Change-Id: I80c96a7026f2469e6a3ce54344c2d5e617b78be7 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5904414 Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#96387} Refs: v8/v8@323942700cfe PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Reject non-nullable exnref in JS import/export R=jkummerow@chromium.org Change-Id: I0ba2deb1a9671d87e76fea7bfe76df9eee56442a Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5920338 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#96489} Refs: v8/v8@63b8849d73ae PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Fix catchless try_table If the try_table does not have a catch handler, we don't update the {current_catch_} index or set the {previous_catch} field of the block when we enter it. Therefore also skip the reverse operation when the block ends. R=clemensb@chromium.org Fixed: 372261626 Change-Id: Ib3a23e32f9d0ec153d6a00733d96b52cf040e8bd Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5920086 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Clemens Backes <clemensb@chromium.org> Cr-Commit-Position: refs/heads/main@{#96481} Refs: v8/v8@8e214ec PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm] Fix default externref/exnref reference - The default nullexternref should be null instead of undefined - The default exnref/nullexnref should be null instead of wasm_null R=mliedtke@chromium.org Fixed: 372285204,372269618 Change-Id: Id5addce2b196f7ba81aac3c2dd9447a91ed2ce2b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5922878 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Matthias Liedtke <mliedtke@chromium.org> Cr-Commit-Position: refs/heads/main@{#96531} Refs: v8/v8@e7ccf0a PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Accept non-nullable exn catch type R=jkummerow@chromium.org Fixed: 373681572 Change-Id: Iecfc86d2ce6592a6f442bc3504ddde58ff236f64 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5938956 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#96637} Refs: v8/v8@7cb6188 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][js-api] Fix exception handling in Exception Calling `Get` on the third argument can throw. If so, return immediately. R=thibaudm@chromium.org Fixed: 372993873 Change-Id: I70ec0d0421833a60151f6bcdc9c386f6ad864256 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5937803 Reviewed-by: Thibaud Michaud <thibaudm@chromium.org> Commit-Queue: Clemens Backes <clemensb@chromium.org> Cr-Commit-Position: refs/heads/main@{#96627} Refs: v8/v8@b96e40d PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][exnref] Use wasm_null for exnref A JS null caught in wasm as an exnref with catch_(all_)ref should be observably different from a null exnref: a JS null should behave like a regular JS exception with null as the externref package, while a null exnref is the actual null value for this type. In particular, a JS null exception can be rethrown while a null exnref cannot. Represent null exnrefs with wasm_null instead of JS null to avoid the confusion. R=jkummerow@chromium.org Fixed: 374790906 Change-Id: If9f16a24407ee7d1399613255c3f14e0a6ebef9e Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5953226 Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#96782} Refs: v8/v8@9997fc013952 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm] Disallow v128 in exception handling JS API R=jkummerow@chromium.org Fixed: 395214627 Change-Id: Ief84b0fd79a87e539dfbfed31d475926f0f0a288 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6249317 Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#98608} Refs: v8/v8@1b27e4674f11 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Original commit message: [wasm][eh] Fix getArg() when exception has an S128 We cannot read an S128 exception value from JS, but we can read a value at a higher index in the exception. So accept S128 values when we compute the encoded index. R=mliedtke@chromium.org Fixed: 403675482 Change-Id: I7cc0238310863b6d579fcbe0a216ddce6f760c8b Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6367014 Reviewed-by: Matthias Liedtke <mliedtke@chromium.org> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Cr-Commit-Position: refs/heads/main@{#99305} Refs: v8/v8@85b390089e51 PR-URL: #62783 Reviewed-By: Xuguang Mei <meixuguang@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

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guybedford force-pushed the backport-exn-patches branch from 3e2a6d5 to d9bc587 Compare April 17, 2026 15:58

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marco-ippolito closed this May 11, 2026

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2026-05-13, Version 22.22.3 'Jod' (LTS), @marco-ippolito #63250

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guybedford mentioned this pull request Aug 10, 2026

Require node v24 for WASM_EXCEPTIONS feature emscripten-core/emscripten#27105

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kleisauke mentioned this pull request Aug 22, 2026

Disable WASM_LEGACY_EXCEPTIONS by default emscripten-core/emscripten#27575

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[v22.x] deps: V8: backport Wasm exception handling correctness fixes by guybedford · Pull Request #62783 · nodejs/node · GitHub

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[v22.x] deps: V8: backport Wasm exception handling correctness fixes - #62783

[v22.x] deps: V8: backport Wasm exception handling correctness fixes#62783guybedford wants to merge 17 commits intonodejs:v22.x-stagingnodejs/node:v22.x-stagingfrom guybedford:backport-exn-patchesguybedford/node:backport-exn-patchesCopy head branch name to clipboard

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[v22.x] deps: V8: backport Wasm exception handling correctness fixes#62783
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