We currently print reference type indices as unsigned LEB. This will not
work properly for large indices (>=64), as they will be interpreted as
negative indices when read back. They may also alias with builtin types.
In this CL, we fix this by defining builtin types as negative numbers.
We add positive byte constants that can be used in function bodies.
We adapt wasm-module-builder and tests to the above changes.

Bug: v8:7748
Change-Id: I4dfaa65d4cbf77a6731ca2283148bd842ea5c56b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3080569
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76176}

The JS API constructor was renamed to "WebAssembly.Tag" to match the
spec:
https://github.com/WebAssembly/exception-handling/issues/159

Rename "exception" to "tag" throughout the codebase for consistency with
the JS API, and to match the spec terminology (e.g. "tag section").

R=clemensb@chromium.org,nicohartmann@chromium.org

Bug: v8:11992
Change-Id: I63f9f3101abfeefd49117461bd59c594ca5dab70
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3053583Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75994}

- Add d8.file.read() and d8.file.execute() helpers
- Change tools and tests to use new d8.file helper
- Unify error throwing in v8::Shell::ReadFile

Change-Id: I5ef4cb27f217508a367106f01e872a4059d5e399
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2928505
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74883}

First step towards the new exception handling proposal:
https://github.com/WebAssembly/exception-handling/issues/125

This is essentially a revert of:
"[wasm] Switch to new 'catch' and 'br_on_exn' proposal."

The changes are:
- "catch" instruction takes a tag immediate,
- "rethrow" instruction takes a label immediate,
- Add "catch_all" instruction,
- Remove "br_on_exn" instruction,
- Do not push exceptions on the stack, only the encoded values

R=clemensb@chromium.org
CC=​aheejin@chromium.org

Bug: v8:8091
Change-Id: Iea4d8d5a5d3ad50693f645e93c13e8de117aa884
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484514
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71602}

Changes:
- Add possibility to define and emit all reference types.
- Simplify function locals definition.
- Change 'type' to 'type_index' where appropiate.

Bug: v8:7748
Change-Id: Ie35a6204369e678298ee2ff2ec7c7793c5315c3e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2390144
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69814}

Due to recent spec changes, this CL removes the type immediate of
ref.is_null again. Instead we check if the type of the input parameter
is nullable.

R=jkummerow@chromium.org

Bug: v8:10556
Change-Id: If07d30fe4dd27664be7774422573b2ab2b0dfa20
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2247654
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68484}

As per the latest update to the 'reference types' wasm proposal, the
nullref type is removed. Following that, all its uses in V8 were also
removed. This CL:
- Removes now dead code referencing nullref.
- Changes names of functions/exceptions containing 'nullref' to 'null'.
- Changes nullref to the corresponding nullable type in some tests.

Bug: v8:7748
Change-Id: I5b4606671d7b24dd48a45a3341e8a1c056fcd1d0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2238026
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68283}

The reference types wasm proposal dropped all subtyping. Subsequently,
the 'anyref' type was renamed to externref.
This changes all references of the *type* anyref to externref.
Additionally, the flag that permits this extension is renamed to
"reftypes" to mirror the proposal name.

Bug: v8:7748
Change-Id: Icf323f13b9660fd10540e65125af053fca3a03f9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2232941
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68270}

All subtyping has been removed from the reference-types proposal. This
CL implements this proposal change now in V8.

R=manoskouk@chromium.org

Bug: v8:10556
Change-Id: I08ef064952278e03ea655461fa9f0c96426157c7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2222345
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68152}

With recent changes to the anyref proposal, null refs now have a type
immediate which declares the type of a null ref constant. Likewise,
the RefIsNull instruction is type aware now. This CL addresses these
proposal changes now.

R=jkummerow@chromium.org

Bug: v8:10556
Change-Id: I810dfa3a4ab4389afc9639f897cee5d43e9b62cb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2215172
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68141}

The behaviour was clarified in the spec:
https://github.com/WebAssembly/exception-handling/pull/97

br_on_exn (which was done in another CL) and also rethrow should trap on
nullptr. This CL implements this by an explicit check in the builtin
called for rethrow.

R=jkummerow@chromium.org
CC=aheejin@chromium.org

Bug: v8:10128
Change-Id: Icb0f4e54991b3385917bf183efa825048db4cb82
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2115430
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66827}

The behaviour was clarified in the spec:
https://github.com/WebAssembly/exception-handling/pull/97

br_on_exn (and also rethrow, which will be added in another CL) should
trap on nullptr. This CL implements this by an explicit check on each
br_on_exn (within {GetExceptionTag}). This check will be redundant if
several br_on_exn follow each other. Since also the runtime call for
{GetExceptionTag} is redundant, and also the fact that we do a runtime
call is suboptimal, I consider the whole implementation prototypical for
now anyway.

R=jkummerow@chromium.org
CC=aheejin@chromium.org

Bug: v8:10128
Change-Id: I234c3183f93fe0884aadd2ab6dbd6c2b7a07c660
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2113381
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66826}

This extends existing table support to be able to store 'exnref' in
addition to 'anyref' types. Tools can use this to maintain data
structures for exception packages.

R=ahaas@chromium.org
TEST=mjsunit/wasm/exceptions-anyref
BUG=v8:8091

Change-Id: Iccbcfdc328db81a366921bcdd98c2256f66e7fc8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1781046
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64323}

This brings our constants back in line with the changed spec text. We
already use kExprTableGet and kExprTableSet, but for locals and globals
we still use the old wording.

This renaming is mostly mechanical.

PS1 was created using:
ag -l 'kExpr(Get|Set|Tee)Local' src test | \
  xargs -L1 sed -E 's/kExpr(Get|Set|Tee)Local\b/kExprLocal\1/g' -i

PS2 contains manual fixes.

R=mstarzinger@chromium.org

Bug: v8:9810
Change-Id: I1617f1b2a100685a3bf56218e76845a9481959c5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1847354Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64161}

Also see: https://github.com/WebAssembly/exception-handling/pull/84

R=ahaas@chromium.org
BUG=v8:8091

Change-Id: Ibcf9a2bba019cbd634884cb217e1507231a5bcf8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1700077Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62717}

This extends the existing test coverage of interactions between the
exception handling and the reference type proposal. Now "any-func" and
"except-ref" can both be encoded as an exception value. Missing switch
cases have been added.

R=clemensh@chromium.org
TEST=mjsunit/wasm/exceptions-anyref[-interpreter]
BUG=v8:8091,v8:7581

Change-Id: Ie2e9819fe66b4daab623390f27bb19007131f619
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1581600Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60977}

We noticed that almost every call site were loading both files,
the split isn't necessary anymore.

In some message tests, removed the absolute line number to allow future
changes.

Bug: v8:8726
Change-Id: I8527f0a1ecfa685aa01a5e2f5f47ddf1cb13a545
Reviewed-on: https://chromium-review.googlesource.com/c/1446452
Commit-Queue: Sven Sauleau <ssauleau@igalia.com>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59220}

This switches the experimental exception handling implementation to the
new proposal where 'catch' blocks behave in a catch-all fashion and a
new 'br_on_exn' operation is used to check for a certain exception type
and extract the exception values on a match.

R=clemensh@chromium.org
TEST=unittests/FunctionBodyDecoderTest,mjsunit/wasm/exceptions
BUG=v8:8091

Change-Id: Ib12ba28b3aa2a7d831312a83abcb00bf56d0adc3
Reviewed-on: https://chromium-review.googlesource.com/c/1409431
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58832}

R=clemensh@chromium.org

Change-Id: Ie4f40314eb41957c6983796e43eeefe655458160
Reviewed-on: https://chromium-review.googlesource.com/c/1367806
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58118}

This adds support for having reference type values (i.e. anyref) stored
in an exception. It is the natural combination of the reference type
proposal and the exception handling proposal.

Note that this also introduces support for having write barriers in
generated WasmCode, as this is the first time we are storing references
within generated code. Such write barriers will be needed for other uses
of reference types (e.g. mutable global) regardless.

R=clemensh@chromium.org
TEST=mjsunit/wasm/exceptions-anyref
BUG=v8:8341

Change-Id: I1211d4a850954622cb873eede0b4024fecc3dd8b
Reviewed-on: https://chromium-review.googlesource.com/c/1296484
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56995}