[WASM] Exception handling prototype.

[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the
AST construction during bytecode parsing.

BUG=

Committed: https://crrev.com/b2b40134d8ec1a418dd4bc5ac448f6f4278e59a1
Cr-Commit-Position: refs/heads/master@{#38579}

[John, 2016-08-10 17:08:27]

Description was changed from

==========
[WASM] Exception handling prototype.

BUG=
==========

to

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the AST
construction during bytecode parsing.

BUG=
==========

[John, 2016-08-10 17:08:58]

Description was changed from

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the AST
construction during bytecode parsing.

BUG=
==========

to

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the
AST construction during bytecode parsing.

BUG=
==========

[John, 2016-08-10 17:16:17]

The CQ bit was checked by jpp@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-10 17:16:27]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[John, 2016-08-10 17:16:40]

jpp@chromium.org changed reviewers:
+ bradnelson@chromium.org, titzer@chromium.org

[commit-bot: I haz the power, 2016-08-10 17:21:55]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-08-10 17:21:56]

Dry run: Try jobs failed on following builders:
  v8_win64_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win64_rel_ng/builds/12274)
  v8_win_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_rel_ng/builds/12289)

[John, 2016-08-10 17:23:13]

The CQ bit was checked by jpp@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-10 17:23:15]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-10 17:27:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-08-10 17:27:46]

Dry run: Try jobs failed on following builders:
  v8_win_compile_dbg on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_compile_dbg/builds/2...)

[John, 2016-08-10 17:35:04]

The CQ bit was checked by jpp@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-10 17:35:06]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-10 17:58:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-08-10 17:58:44]

Dry run: This issue passed the CQ dry run.

[bradnelson, 2016-08-11 00:39:29]

lgtm

https://codereview.chromium.org/2222193004/diff/120001/src/wasm/ast-decoder.cc
File src/wasm/ast-decoder.cc (right):

https://codereview.chromium.org/2222193004/diff/120001/src/wasm/ast-decoder.c...
src/wasm/ast-decoder.cc:72: SsaEnv* cont_env;   // continuation environment
(only for try with finally).
This name is confusing, implies continue as in the statement / loops, and
happens to match a local down in Loop.
How about finish_try_env, or if you can think of better?

https://codereview.chromium.org/2222193004/diff/120001/test/unittests/wasm/as...
File test/unittests/wasm/ast-decoder-unittest.cc (right):

https://codereview.chromium.org/2222193004/diff/120001/test/unittests/wasm/as...
test/unittests/wasm/ast-decoder-unittest.cc:1836: // TODO(jpp): can't throw d,
f, or l.
Wait just to clarify.
You're asserting the current behavior, but the intention is to restrict to
int32?

[John, 2016-08-11 11:22:27]

https://codereview.chromium.org/2222193004/diff/120001/src/wasm/ast-decoder.cc
File src/wasm/ast-decoder.cc (right):

https://codereview.chromium.org/2222193004/diff/120001/src/wasm/ast-decoder.c...
src/wasm/ast-decoder.cc:72: SsaEnv* cont_env;   // continuation environment
(only for try with finally).
On 2016/08/11 00:39:29, bradnelson wrote:
> This name is confusing, implies continue as in the statement / loops, and
> happens to match a local down in Loop.
> How about finish_try_env, or if you can think of better?

Yeah, cont_env threw me off a few times, but I couldn't come up with anything
better. Going with finish_try_env.

https://codereview.chromium.org/2222193004/diff/120001/test/unittests/wasm/as...
File test/unittests/wasm/ast-decoder-unittest.cc (right):

https://codereview.chromium.org/2222193004/diff/120001/test/unittests/wasm/as...
test/unittests/wasm/ast-decoder-unittest.cc:1836: // TODO(jpp): can't throw d,
f, or l.
On 2016/08/11 00:39:29, bradnelson wrote:
> Wait just to clarify.
> You're asserting the current behavior, but the intention is to restrict to
> int32?

Yes. I am testing the (current) implementation, leaving the TODO behind so that
once the implementation is finished I'll remember why these tests are failing.

[John, 2016-08-11 11:23:03]

The CQ bit was checked by jpp@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-11 11:23:08]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-11 12:14:17]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-08-11 12:14:17]

Dry run: This issue passed the CQ dry run.

[John, 2016-08-11 13:12:45]

The CQ bit was checked by jpp@chromium.org

[John, 2016-08-11 13:12:46]

The patchset sent to the CQ was uploaded after l-g-t-m from
bradnelson@chromium.org
Link to the patchset: https://codereview.chromium.org/2222193004/#ps140001
(title: "addresses comments")

[commit-bot: I haz the power, 2016-08-11 13:12:57]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-11 13:14:54]

Description was changed from

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the
AST construction during bytecode parsing.

BUG=
==========

to

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the
AST construction during bytecode parsing.

BUG=
==========

[commit-bot: I haz the power, 2016-08-11 13:14:58]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2016-08-11 13:15:17]

Description was changed from

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the
AST construction during bytecode parsing.

BUG=
==========

to

==========
[WASM] Exception handling prototype.
------------------------------------------------------------------------

This CL adds support for decoding eh-related wasm opcodes:
* Throw: used for raising an exception; the thrown value lives on top of
         the evaluation stack;
* TryCatch: used to start a try block that has a catch clause;
* TryFinally: used to start a try block that has a finally clause;
* TryCatchFinally: used to start a try block that has both catch and
                   finally clauses;
* Catch <local>: used to start the catch block of a
                 TryCatch/TryCatchFinally block; the thrown value is
                 stored in local <local>; and
* Finally: used to start a finally block of TryFinally/TryCatchFinally.

Three different opcodes are used to start a try block to simplify the
AST construction during bytecode parsing.

BUG=

Committed: https://crrev.com/b2b40134d8ec1a418dd4bc5ac448f6f4278e59a1
Cr-Commit-Position: refs/heads/master@{#38579}
==========

[commit-bot: I haz the power, 2016-08-11 13:15:18]

Patchset 8 (id:??) landed as
https://crrev.com/b2b40134d8ec1a418dd4bc5ac448f6f4278e59a1
Cr-Commit-Position: refs/heads/master@{#38579}