Context independent CodeBlocks

[HalidOdat]

Fixes/Closes #2626

This allows us to share CodeBlocks between Context, which makes functions sharable between Contexts.

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	95,609	95,609	0
Passed	76,526	76,526	0
Ignored	18,132	18,132	0
Failed	951	951	0
Panics	0	0	0
Conformance	80.04%	80.04%	0.00%

[codecov]

Codecov Report

Attention: 256 lines in your changes are missing coverage. Please review.

Comparison is base (b2223cb) 44.59% compared to head (98f447b) 44.66%.
Report is 5 commits behind head on main.

Files	Patch %	Lines
boa_engine/src/module/source.rs	0.00%	67 Missing ⚠️
boa_engine/src/vm/code_block.rs	0.00%	32 Missing ⚠️
boa_engine/src/bytecompiler/declarations.rs	59.45%	30 Missing ⚠️
boa_engine/src/bytecompiler/mod.rs	64.38%	26 Missing ⚠️
boa_engine/src/module/mod.rs	0.00%	19 Missing ⚠️
boa_engine/src/bytecompiler/statement/loop.rs	69.44%	11 Missing ⚠️
...ne/src/object/internal_methods/module_namespace.rs	0.00%	11 Missing ⚠️
boa_engine/src/vm/opcode/set/name.rs	47.05%	9 Missing ⚠️
boa_engine/src/module/synthetic.rs	0.00%	6 Missing ⚠️
boa_examples/src/bin/synthetic.rs	0.00%	6 Missing ⚠️
... and 16 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3424      +/-   ##
==========================================
+ Coverage   44.59%   44.66%   +0.07%     
==========================================
  Files         487      487              
  Lines       50601    50640      +39     
==========================================
+ Hits        22563    22620      +57     
+ Misses      28038    28020      -18     

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[HalidOdat]

Ideally we would make the interner store JsStrings and when we .resolve_expect() it would return a JsString, this would simplify our compiler logic.

[jedel1043]

Does this affect performance in any way? Just thinking that copying Identifier was pretty cheap, but cloning a JsString involves incrementing a Cell.

The other alternative would be to have an API similar to V8's, where scripts are "linked" to contexts, and you can unlink them and relink them to other contexts if you need to.

[HalidOdat]

Does this affect performance in any way?

Yes, there is a small perf. increase.

main:

PROGRESS Richards
RESULT Richards 35.0
PROGRESS DeltaBlue
RESULT DeltaBlue 39.8
PROGRESS Encrypt
PROGRESS Decrypt
RESULT Crypto 54.5
PROGRESS RayTrace
RESULT RayTrace 135
PROGRESS Earley
PROGRESS Boyer
RESULT EarleyBoyer 114

PR:

PROGRESS Richards
RESULT Richards 36.2
PROGRESS DeltaBlue
RESULT DeltaBlue 41.9
PROGRESS Encrypt
PROGRESS Decrypt
RESULT Crypto 55.5
PROGRESS RayTrace
RESULT RayTrace 140
PROGRESS Earley
PROGRESS Boyer
RESULT EarleyBoyer 116

NOTE: I didn't run all of them, the RegExp takes a lot of time (+10mins). Not sure when it got fixed, probably in #3338?

Just thinking that copying Identifier was pretty cheap, but cloning a JsString involves incrementing a Cell.

I'm fine with keeping Identifier in AST, we should only change the interners internal string store to be JsString instead of InternedStr<u16>, it would remove the back and forth conversions. This would require either moving JsString to a separate crate (probably the better choice) or in boa_interner crate.

The other alternative would be to have an API similar to V8's, where scripts are "linked" to contexts, and you can unlink them and relink them to other contexts if you need to.

Sounds interesting! Is there any resource that describes this? :)

[jedel1043]

Sounds interesting! Is there any resource that describes this? :)

I don't think V8 has an example on how to use that API, but Script is split into an UnboundScript (the data that doesn't depend on the current context) and the rest of the context-dependent data. Then, UnboundScript has a method to bind the script to a Context:
https://github.com/v8/v8/blob/2465184635ae2c2237ea13afe3bb395eae7f94bd/include/v8-script.h#L62-L65

I think it's slightly more flexible, since an UnboundScript can be shared between many Contexts, and you can always recover the shared UnboundScript from the Script:
https://github.com/v8/v8/blob/7fdc2728f2114b083ebbd24710a32fe4574c0c57/src/api/api.cc#L2153-L2159

[jedel1043]

@jedel1043 and @raskad will review this.

[raskad]

Really nice, I just got one comment.

[jedel1043]

Note for later: see if we can avoid taking interner as a parameter on this, to make it a bit more similar to the ToString trait.

[jedel1043]

Looks great!