Execution and Node modularization

[Razican]

The idea behind this work is to divide the exec and ast::node modules in smaller code pieces. I also want to solve #376 in the process, and maybe #377.

This is the progress as of now:

• Node::ArrayDecl
• Node::ArrowFunctionDecl
• Node::Assign
• Node::BinOp
• Node::Block
• Node::Break
• Node::Call
• Node::ConditionalOp
• Node::Const
• Node::ConstDecl => Node::ConstDeclList
• Node::Continue
• Node::DoWhileLoop
• Node::FunctionDecl
• Node::FunctionExpr
• Node::GetConstField
• Node::GetField
• Node::ForLoop
• Node::If
• Node::LetDecl => Node::LetDeclList
• Node::Local => Node::Identifier
• Node::New
• Node::Object
• Node::Return
• Node::Switch
• Node::Spread
• Node::StatementList (no longer a node)
• Node::Throw
• Node::Try
• Node::This (no change)
• Node::UnaryOp
• Node::VarDecl => Node::VarDeclList
• Node::WhileLoop

I also added the Executable trait, and I'm modifying the Executor trait in order for external libraries to provide their own executors. We could also just remove the Executor trait if we don't want to offer this option.

[github-actions]

Benchmark for a84b7d1

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	418.2±10.07µs	417.4±9.69µs	100%
Expression (Lexer)	2.0±0.09µs	2.0±0.06µs	100%
Expression (Parser)	5.2±0.17µs	5.2±0.09µs	101%
Fibonacci (Execution)	2.9±0.08ms	3.0±0.07ms	99%
For loop (Execution)	443.6±12.80µs	440.0±10.26µs	101%
For loop (Lexer)	5.3±0.20µs	5.4±0.21µs	99%
For loop (Parser)	14.7±0.53µs	14.8±0.75µs	99%
Hello World (Lexer)	932.0±16.92ns	937.6±22.56ns	99%
Hello World (Parser)	2.3±0.06µs	2.4±0.12µs	96%
Symbols (Execution)	448.9±20.10µs	444.2±14.72µs	101%
	undefined	undefined	100%

[github-actions]

Benchmark for 3567431

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Test	PR Benchmark	Master Benchmark	%
Create Realm	411.2±6.65µs	415.2±8.82µs	99%
Expression (Lexer)	1995.3±27.46ns	2.1±0.05µs	97%
Expression (Parser)	5.1±0.08µs	5.1±0.06µs	101%
Fibonacci (Execution)	2.9±0.13ms	2.9±0.03ms	100%
For loop (Execution)	433.1±7.26µs	432.4±4.32µs	100%
For loop (Lexer)	5.2±0.06µs	5.3±0.07µs	98%
For loop (Parser)	14.2±0.18µs	14.5±0.31µs	98%
Hello World (Lexer)	933.4±26.69ns	933.5±15.05ns	100%
Hello World (Parser)	2.3±0.02µs	2.3±0.03µs	101%
Symbols (Execution)	440.9±8.64µs	436.5±5.05µs	101%
	undefined	undefined	100%

[github-actions]

Benchmark for ab63b70

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Test	PR Benchmark	Master Benchmark	%
Create Realm	426.6±8.40µs	432.8±20.42µs	99%
Expression (Lexer)	2.1±0.06µs	2.1±0.04µs	102%
Expression (Parser)	5.3±0.25µs	5.2±0.16µs	101%
Fibonacci (Execution)	3.2±0.08ms	3.3±0.07ms	99%
For loop (Execution)	478.6±17.93µs	460.4±37.19µs	104%
For loop (Lexer)	5.6±0.21µs	5.7±0.21µs	99%
For loop (Parser)	15.6±0.43µs	15.3±0.34µs	102%
Hello World (Lexer)	1020.3±38.35ns	991.3±26.54ns	103%
Hello World (Parser)	2.5±0.07µs	2.5±0.05µs	100%
Symbols (Execution)	475.8±12.17µs	469.9±14.16µs	101%
	undefined	undefined	100%

[github-actions]

Benchmark for f3a168d

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	377.3±15.26µs	375.8±15.28µs	100%
Expression (Lexer)	1799.3±57.79ns	1843.4±47.23ns	98%
Expression (Parser)	4.6±0.10µs	4.6±0.12µs	99%
Fibonacci (Execution)	2.7±0.08ms	2.6±0.07ms	101%
For loop (Execution)	399.8±13.88µs	394.0±15.77µs	101%
For loop (Lexer)	4.8±0.15µs	4.8±0.16µs	99%
For loop (Parser)	13.0±0.29µs	13.2±0.34µs	99%
Hello World (Lexer)	858.1±27.22ns	862.4±20.30ns	100%
Hello World (Parser)	2.1±0.08µs	2.1±0.06µs	100%
Symbols (Execution)	407.1±13.87µs	408.3±18.49µs	100%
	undefined	undefined	100%

[github-actions]

Benchmark for 8849ae3

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Test	PR Benchmark	Master Benchmark	%
Create Realm	397.5±9.41µs	397.0±7.70µs	100%
Expression (Lexer)	1891.4±50.48ns	1924.5±109.63ns	98%
Expression (Parser)	4.9±0.11µs	4.9±0.07µs	99%
Fibonacci (Execution)	2.8±0.05ms	2.8±0.03ms	99%
For loop (Execution)	416.7±6.64µs	417.7±12.83µs	100%
For loop (Lexer)	5.2±0.09µs	5.0±0.13µs	104%
For loop (Parser)	13.8±0.22µs	13.9±0.14µs	99%
Hello World (Lexer)	907.7±17.77ns	888.7±13.25ns	102%
Hello World (Parser)	2.2±0.10µs	2.3±0.05µs	99%
Symbols (Execution)	442.1±45.35µs	428.0±11.12µs	103%
	undefined	undefined	100%

[github-actions]

Benchmark for 91b0b79

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Test	PR Benchmark	Master Benchmark	%
Create Realm	403.5±20.34µs	422.2±17.62µs	95%
Expression (Lexer)	1962.9±95.66ns	2.0±0.09µs	98%
Expression (Parser)	4.7±0.25µs	5.0±0.22µs	94%
Fibonacci (Execution)	3.1±0.10ms	3.1±0.09ms	98%
For loop (Execution)	433.1±18.33µs	457.0±21.22µs	94%
For loop (Lexer)	5.2±0.26µs	5.0±0.23µs	105%
For loop (Parser)	15.4±0.85µs	14.7±1.82µs	105%
Hello World (Lexer)	921.6±52.22ns	916.9±48.20ns	101%
Hello World (Parser)	2.3±0.14µs	2.3±0.10µs	102%
Symbols (Execution)	432.3±17.25µs	460.6±19.64µs	93%
	undefined	undefined	100%

[github-actions]

Benchmark for 5083e07

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Test	PR Benchmark	Master Benchmark	%
Create Realm	416.7±15.84µs	401.0±13.04µs	104%
Expression (Lexer)	1926.6±80.65ns	1985.1±100.35ns	97%
Expression (Parser)	6.2±0.18µs	5.1±0.23µs	121%
Fibonacci (Execution)	2.9±0.11ms	2.8±0.20ms	104%
For loop (Execution)	449.0±18.67µs	425.0±17.85µs	106%
For loop (Lexer)	5.1±0.17µs	5.2±0.25µs	99%
For loop (Parser)	16.8±0.65µs	14.3±0.60µs	117%
Hello World (Lexer)	923.0±42.76ns	905.8±33.65ns	102%
Hello World (Parser)	2.7±0.11µs	2.3±0.07µs	118%
Symbols (Execution)	441.3±18.33µs	432.3±14.90µs	102%
	undefined	undefined	100%

[github-actions]

Benchmark for ec9295e

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Test	PR Benchmark	Master Benchmark	%
Create Realm	434.9±11.86µs	419.6±13.04µs	104%
Expression (Lexer)	2.1±0.06µs	2.1±0.09µs	98%
Expression (Parser)	6.2±0.25µs	5.2±0.19µs	119%
Fibonacci (Execution)	3.2±0.09ms	3.1±0.08ms	105%
For loop (Execution)	470.2±13.12µs	444.8±14.35µs	106%
For loop (Lexer)	5.4±0.21µs	5.4±0.24µs	100%
For loop (Parser)	17.6±0.55µs	15.1±0.58µs	117%
Hello World (Lexer)	986.5±58.30ns	996.9±36.77ns	99%
Hello World (Parser)	2.9±0.09µs	2.4±0.11µs	117%
Symbols (Execution)	466.6±16.00µs	447.3±13.44µs	104%
	undefined	undefined	100%

[github-actions]

Benchmark for fdcdf09

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	411.0±12.49µs	398.9±8.62µs	103%
Expression (Lexer)	1946.6±50.74ns	1942.6±77.15ns	100%
Expression (Parser)	5.1±0.21µs	4.9±0.49µs	102%
Fibonacci (Execution)	2.8±0.05ms	2.8±0.08ms	98%
For loop (Execution)	424.4±9.58µs	434.2±26.63µs	98%
For loop (Lexer)	5.1±0.07µs	5.1±0.13µs	101%
For loop (Parser)	13.7±0.50µs	13.9±0.36µs	98%
Hello World (Lexer)	932.5±33.96ns	895.4±24.45ns	104%
Hello World (Parser)	2.3±0.22µs	2.3±0.08µs	99%
Symbols (Execution)	435.2±22.94µs	420.8±9.46µs	103%
	undefined	undefined	100%

[github-actions]

Benchmark for 954ad85

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	365.4±36.21µs	390.9±37.86µs	93%
Expression (Lexer)	1778.2±136.68ns	1759.5±124.30ns	101%
Expression (Parser)	5.5±0.41µs	5.0±0.31µs	111.00000000000001%
Fibonacci (Execution)	2.7±0.18ms	2.9±0.18ms	90.99999999999999%
For loop (Execution)	376.9±30.90µs	403.4±40.90µs	93%
For loop (Lexer)	4.9±0.40µs	5.0±0.59µs	96%
For loop (Parser)	14.6±1.24µs	14.0±1.62µs	104%
Hello World (Lexer)	883.0±106.85ns	882.7±77.94ns	100%
Hello World (Parser)	2.5±0.25µs	2.1±0.16µs	115.99999999999999%
Symbols (Execution)	375.6±29.88µs	400.0±42.68µs	93%
	undefined	undefined	100%

[Razican]

A small update on the changes I made:
I removed the StatementList node for now, and simplified some nodes to have less indirections.

This has added a bit of extra complexity in the parser, which brings the times up a bit, but they are clearly minor compared to the huge gains in execution. This should improve further as I continue modularizing more nodes.

I also removed the Executor trait for now. I don't think it makes sense for other crates to create their own Boa interpreters. It was almost impossible to use it before that way anyways. This has simplified the execution and reduces compile times.

I also added a preliminary version of hoisting, but it's not 100% spec compliant yet.

[Razican]

Some more changes:

• Tokens now have a Span instead of a Position. This should make it easier to implement Span nodes #300, or even better diagnostics of errors if we get into that.
• Positions and spans are now properly checked on creation: no more positions with 0 as the column or line number, no more spans that end before they start. This brought up many errors with token positions that should now be fixed.
• Positions use now NonZeroU32 for column and line numbers instead of u32. This means that a whole position now occupies only 64 bits, instead of 128, and enter in a word in most recent processors. It also brings some optimisations if we use Option<Position>. This should make a Token a bit smaller, and thus easier to pass around, and should give some performance optimisations.
• Constants no longer have a String if they are of type String, they will have a Box<str>, this gives us some space optimisation in both heap an stack. String interning #279 should help with this too, by making all tokens Copy.
• The helper structure used to lex numbers is now smaller and Copy, which should improve performance in this area.
• Hoisting is now 100% spec compliant (!), at least with the tests I did.
• Node::Local is now Node::Identifier. I thought this name made more sense, and it's the name V8 uses.
• All non-mutable String-s have been replaced by Box<str> in Node. This will reduce the size of a Node.

Still many things to do, but this modularization is already showing big performance improvements. In the future, I would like to modify the Assign node and others to allow only for 3 types of nodes in the left hand side. This would avoid one boxing and therefore improve performance.

[github-actions]

Benchmark for b8899e2

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	393.9±15.86µs	391.5±15.84µs	101%
Expression (Lexer)	2.1±0.08µs	1919.6±93.58ns	111.00000000000001%
Expression (Parser)	5.0±0.25µs	4.8±0.22µs	105%
Fibonacci (Execution)	2.9±0.09ms	2.9±0.10ms	99%
For loop (Execution)	424.1±14.17µs	425.1±24.42µs	100%
For loop (Lexer)	5.5±0.23µs	5.1±0.25µs	109.00000000000001%
For loop (Parser)	15.1±0.81µs	14.2±0.62µs	106%
Hello World (Lexer)	1037.7±42.89ns	981.4±99.83ns	106%
Hello World (Parser)	2.3±0.08µs	2.3±0.09µs	101%
Symbols (Execution)	439.3±23.73µs	423.9±17.66µs	104%
	undefined	undefined	100%

[github-actions]

Benchmark for 9db5584

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Test	PR Benchmark	Master Benchmark	%
Create Realm	401.3±25.71µs	406.0±31.53µs	99%
Expression (Lexer)	2.2±0.07µs	1837.8±75.95ns	118%
Expression (Parser)	4.7±0.34µs	4.9±0.37µs	96%
Fibonacci (Execution)	2.7±0.16ms	3.0±0.17ms	93%
For loop (Execution)	387.1±35.34µs	392.4±35.50µs	99%
For loop (Lexer)	5.3±0.40µs	4.4±0.48µs	120%
For loop (Parser)	15.0±1.91µs	14.6±0.59µs	103%
Hello World (Lexer)	1103.2±119.89ns	930.6±53.33ns	119%
Hello World (Parser)	2.4±0.08µs	2.2±0.30µs	111.00000000000001%
Symbols (Execution)	425.4±21.04µs	452.5±41.53µs	94%
	undefined	undefined	100%

[github-actions]

Benchmark for 157482b

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	397.2±9.35µs	403.3±20.39µs	98%
Expression (Lexer)	2.1±0.03µs	1934.5±50.61ns	107%
Expression (Parser)	5.2±0.08µs	5.0±0.07µs	105%
Fibonacci (Execution)	2.8±0.04ms	2.8±0.05ms	99%
For loop (Execution)	419.0±13.38µs	425.2±7.31µs	99%
For loop (Lexer)	5.5±0.11µs	5.2±0.36µs	105%
For loop (Parser)	13.9±0.32µs	14.0±0.46µs	100%
Hello World (Lexer)	1012.0±22.43ns	968.2±16.09ns	105%
Hello World (Parser)	2.3±0.04µs	2.3±0.03µs	99%
Symbols (Execution)	421.3±8.64µs	428.7±7.60µs	98%
	undefined	undefined	100%

[github-actions]

Benchmark for c4bc22b

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Test	PR Benchmark	Master Benchmark	%
Create Realm	413.7±11.98µs	430.8±6.79µs	96%
Expression (Lexer)	2.3±0.12µs	2.2±0.12µs	108%
Expression (Parser)	5.5±0.15µs	5.3±0.18µs	104%
Fibonacci (Execution)	3.1±0.07ms	3.2±0.05ms	99%
For loop (Execution)	447.0±13.53µs	459.5±15.37µs	97%
For loop (Lexer)	5.9±0.22µs	5.4±0.17µs	109.00000000000001%
For loop (Parser)	15.5±0.48µs	15.1±0.41µs	103%
Hello World (Lexer)	1121.6±42.92ns	1074.3±61.42ns	104%
Hello World (Parser)	2.5±0.10µs	2.5±0.07µs	102%
Symbols (Execution)	444.0±14.39µs	484.0±18.09µs	90.99999999999999%
	undefined	undefined	100%

[github-actions]

Benchmark for 36278f7

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	401.0±14.86µs	408.4±9.87µs	98%
Expression (Lexer)	2.2±0.05µs	1978.7±41.25ns	109.00000000000001%
Expression (Parser)	5.0±0.05µs	4.9±0.13µs	100%
Fibonacci (Execution)	3.0±0.06ms	3.1±0.07ms	97%
For loop (Execution)	426.3±11.71µs	432.3±13.05µs	99%
For loop (Lexer)	5.4±0.14µs	5.3±0.20µs	104%
For loop (Parser)	14.5±1.09µs	14.8±0.44µs	98%
Hello World (Lexer)	1038.5±18.04ns	998.9±28.46ns	104%
Hello World (Parser)	2.3±0.12µs	2.4±0.10µs	95%
Symbols (Execution)	434.6±34.98µs	445.8±23.53µs	97%
	undefined	undefined	100%

[github-actions]

Benchmark for c1897e3

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	396.0±13.98µs	397.8±15.82µs	100%
Expression (Lexer)	2.1±0.11µs	1963.2±114.34ns	105%
Expression (Parser)	5.1±0.14µs	5.1±0.19µs	100%
Fibonacci (Execution)	2.6±0.12ms	2.6±0.17ms	99%
For loop (Execution)	416.8±17.62µs	432.5±22.10µs	96%
For loop (Lexer)	5.5±0.14µs	5.3±0.20µs	105%
For loop (Parser)	13.9±0.36µs	14.8±1.07µs	93%
Hello World (Lexer)	991.2±43.00ns	948.7±21.98ns	104%
Hello World (Parser)	2.3±0.15µs	2.4±0.04µs	97%
Symbols (Execution)	424.7±8.54µs	417.8±18.45µs	102%
	undefined	undefined	100%

[github-actions]

Benchmark for df82a0f

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	430.1±24.35µs	412.1±14.45µs	104%
Expression (Lexer)	2.3±0.13µs	2.1±0.12µs	108%
Expression (Parser)	5.5±0.25µs	5.2±0.30µs	105%
Fibonacci (Execution)	2.9±0.16ms	3.0±0.10ms	98%
For loop (Execution)	442.1±21.03µs	457.9±20.62µs	96%
For loop (Lexer)	5.7±0.24µs	5.4±0.28µs	105%
For loop (Parser)	15.0±1.03µs	15.2±0.76µs	99%
Hello World (Lexer)	1067.8±56.03ns	1053.7±61.45ns	101%
Hello World (Parser)	2.4±0.13µs	2.5±0.13µs	97%
Symbols (Execution)	449.2±25.60µs	451.6±18.35µs	99%
	undefined	undefined	100%

[github-actions]

Benchmark for 9c87c48

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	422.2±20.46µs	426.0±10.89µs	99%
Expression (Lexer)	2.3±0.07µs	2.1±0.13µs	108%
Expression (Parser)	5.3±0.15µs	5.2±0.16µs	101%
Fibonacci (Execution)	2.9±0.09ms	2.9±0.09ms	100%
For loop (Execution)	447.2±12.64µs	452.0±17.06µs	99%
For loop (Lexer)	5.8±0.24µs	5.7±0.21µs	102%
For loop (Parser)	14.7±0.35µs	15.5±0.58µs	94%
Hello World (Lexer)	1073.8±34.84ns	1065.1±20.53ns	101%
Hello World (Parser)	2.4±0.07µs	2.5±0.08µs	95%
Symbols (Execution)	443.8±13.32µs	450.8±11.99µs	98%
	undefined	undefined	100%

[github-actions]

Benchmark for fff8e38

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	339.6±15.62µs	338.2±24.27µs	100%
Expression (Lexer)	1751.7±204.55ns	1542.8±91.81ns	113.99999999999999%
Expression (Parser)	4.1±0.38µs	4.1±0.27µs	102%
Fibonacci (Execution)	2.3±0.10ms	2.4±0.10ms	96%
For loop (Execution)	353.1±19.76µs	354.4±36.33µs	100%
For loop (Lexer)	4.4±0.32µs	4.3±0.28µs	104%
For loop (Parser)	11.4±0.65µs	13.0±1.39µs	86.00000000000001%
Hello World (Lexer)	818.5±54.65ns	793.6±51.80ns	103%
Hello World (Parser)	1829.6±105.37ns	1904.2±116.60ns	96%
Symbols (Execution)	356.4±21.22µs	349.3±23.15µs	102%
	undefined	undefined	100%

[github-actions]

Benchmark for 2c449a5

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Create Realm	436.7±13.69µs	416.5±13.83µs	105%
Expression (Lexer)	2.2±0.07µs	2.0±0.06µs	109.00000000000001%
Expression (Parser)	5.3±0.06µs	5.4±0.26µs	99%
Fibonacci (Execution)	2.7±0.04ms	2.8±0.04ms	99%
For loop (Execution)	460.0±25.44µs	448.9±8.91µs	102%
For loop (Lexer)	5.8±0.11µs	5.5±0.17µs	105%
For loop (Parser)	14.5±0.41µs	15.1±0.29µs	96%
Hello World (Lexer)	1050.7±31.70ns	998.1±25.14ns	105%
Hello World (Parser)	2.4±0.05µs	2.5±0.06µs	98%
Symbols (Execution)	458.5±7.30µs	442.1±5.62µs	104%
	undefined	undefined	100%

[Razican]

@jasonwilliams, @HalidOdat I think this is ready for review, in the sense that there are some nodes left, but the architecture is there. I'm starting to see that future future PRs will make merges very difficult, so I think we can land a preliminary version of this, and then modularize the rest of the nodes (and the tests) in another PR.

This PR notably fixes #376 (with a workaround), #336 and #377.

It adds a Span to the tokens, so it will be relativelly easy to implement #300. And of course, it does great progress towards #366, I will add the mising nodes to that issue.

Let me know what you think :)

PS: I also modified all static strings to be Box<str>, but this required a change in rust-gc. We would need for rust-gc to publish a new version in crates.io for this to be mergeable. We will need the help of @Manishearth for this :)

[HalidOdat]

This looks simply awesome!!! Good work as usual!

With 122 files changed there will be a lot of merge conflicts with future PRs so we should merge this ASAP :)

[jasonwilliams]

Will find some time to take a look at this

PS: I also modified all static strings to be Box, but this required a change in rust-gc. We would need for rust-gc to publish a new version in crates.io for this to be mergeable. We will need the help of @Manishearth for this :)

So we need that to be merged before this then, is there a link to that PR or issue?

[Razican]

PS: I also modified all static strings to be Box, but this required a change in rust-gc. We would need for rust-gc to publish a new version in crates.io for this to be mergeable. We will need the help of @Manishearth for this :)

So we need that to be merged before this then, is there a link to that PR or issue?

It was already merged, we only need a release in crates.io :D

[Manishearth]

Published

[Razican]

Published

Great! I updated the dependencies, without the Git dependency, so this is ready to be merged!

[jasonwilliams]

Looks good to me, lets merge and carry on after