feat(blockifier): add NativeSyscallHandler

[rodrigo-pino]

Recration of #1157 targeting Main

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This change is 

[codecov]

Codecov Report

Attention: Patch coverage is 10.24590% with 219 lines in your changes missing coverage. Please review.

Project coverage is 69.30%. Comparing base (b0cfe82) to head (e9d7c2a).
Report is 313 commits behind head on main.

Files with missing lines	Patch %	Lines
...blockifier/src/execution/native/syscall_handler.rs	0.00%	219 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1240      +/-   ##
==========================================
- Coverage   74.18%   69.30%   -4.89%     
==========================================
  Files         359       88     -271     
  Lines       36240    11803   -24437     
  Branches    36240    11803   -24437     
==========================================
- Hits        26886     8180   -18706     
+ Misses       7220     3256    -3964     
+ Partials     2134      367    -1767     

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[meship-starkware]

Reviewed 3 of 4 files at r1.
Reviewable status: 2 of 5 files reviewed, all discussions resolved

[noaov1]

Reviewed 1 of 4 files at r1, 1 of 1 files at r2, 1 of 1 files at r6, all commit messages.
Reviewable status: 4 of 5 files reviewed, 2 unresolved discussions (waiting on @meship-starkware and @rodrigo-pino)

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crates/blockifier/src/execution/native/utils.rs line 22 at r7 (raw file):

        encoding[i] = Felt::from_bytes_be(&chunk);
    }
    encoding

The chunks are of size 31 (as well as data_chunk.
chunk is of size 32.
We write at indices 1-31 the value of data_chunk as the MSB no?
It's different than what we do in the constants messages, right?

Suggestion:

    let data = msg.as_bytes().chunks(CHUNK_SIZE - 1);
    let mut encoding = vec![];
    for data_chunk in data.iter() {
        let mut chunk = [0_u8; CHUNK_SIZE];
        chunk[1..data_chunk.len() + 1].copy_from_slice(data_chunk);
        encoding.push(Felt::from_bytes_be(&chunk));
    }
    encoding

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crates/blockifier/src/execution/native/utils.rs line 27 at r7 (raw file):

// Todo(rodrigo): This is an opinionated way of interpretting error messages. It's ok for now but I
// think it can be improved; (for example) trying to make the output similar to a Cairo VM panic
pub fn decode_felts_as_str(encoding: &[Felt]) -> String {

When will it be used?

Code quote:

pub fn decode_felts_as_str(encoding: &[Felt]) -> String {

[meship-starkware]

Reviewed 1 of 1 files at r6.
Reviewable status: 4 of 5 files reviewed, 2 unresolved discussions (waiting on @rodrigo-pino)

[rodrigo-pino]

Reviewable status: 4 of 5 files reviewed, 2 unresolved discussions (waiting on @meship-starkware and @noaov1)

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crates/blockifier/src/execution/native/utils.rs line 22 at r7 (raw file):

We write at indices 1-31 the value of data_chunk as the MSB no?
It's different than what we do in the constants messages, right?

I'd have to dive a bit deep in the code to answer a 100% sure but I think is not. Both messages are encoded in the same fashion as your error messages. When they get decoded during execution we don't see any word being reversed 🤔

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crates/blockifier/src/execution/native/utils.rs line 27 at r7 (raw file):

Previously, noaov1 (Noa Oved) wrote…

When will it be used?

When outputting the final error message, after Cairo Native returned control if there was a failure, the message is contained in a Vec<Felt>

[noaov1]

Reviewable status: 4 of 5 files reviewed, 3 unresolved discussions (waiting on @meship-starkware and @rodrigo-pino)

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crates/blockifier/src/execution/native/utils.rs line 22 at r7 (raw file):

Previously, rodrigo-pino (Rodrigo) wrote…

We write at indices 1-31 the value of data_chunk as the MSB no?
It's different than what we do in the constants messages, right?

I'd have to dive a bit deep in the code to answer a 100% sure but I think is not. Both messages are encoded in the same fashion as your error messages. When they get decoded during execution we don't see any word being reversed 🤔

I tried to decode it and it seems to result with the same "Out of gas" message. I guess it's because you remove the 0's (in prefix and suffix). Makes sense?

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crates/blockifier/src/execution/native/utils.rs line 34 at r7 (raw file):

        // If the string is utf8 make sure it is not prefixed by no null chars. Null chars in
        // between can still happen
        Ok(s) => s.trim_matches('\0').to_owned(),

Can it be problematic? Consider the error message: "Not supporting Cairo 0". It's hex is "4E 6F 74 20 73 75 70 70 6F 72 74 69 6E 67 20 43 61 69 72 6F 20 30", so trimming the last zero can be problematic.

Code quote:

Ok(s) => s.trim_matches('\0').to_owned(),

[meship-starkware]

Reviewed 1 of 1 files at r2.
Reviewable status: 4 of 5 files reviewed, 3 unresolved discussions (waiting on @rodrigo-pino)

[PearsonWhite]

Reviewable status: 4 of 5 files reviewed, 3 unresolved discussions (waiting on @meship-starkware, @noaov1, and @rodrigo-pino)

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crates/blockifier/src/execution/native/utils.rs line 27 at r7 (raw file):

Previously, rodrigo-pino (Rodrigo) wrote…

When outputting the final error message, after Cairo Native returned control if there was a failure, the message is contained in a Vec<Felt>

It's used in the syscall_handler.rs execute_inner_call to translate the CallEntryPoint.

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crates/blockifier/src/execution/native/utils.rs line 34 at r7 (raw file):

Previously, noaov1 (Noa Oved) wrote…

Can it be problematic? Consider the error message: "Not supporting Cairo 0". It's hex is "4E 6F 74 20 73 75 70 70 6F 72 74 69 6E 67 20 43 61 69 72 6F 20 30", so trimming the last zero can be problematic.

I don't think this will match unicode 0s. I can't reproduce an error with the test string "Not supporting Cairo 0" in "test_encode_decode_str".

[noaov1]

Reviewed 1 of 4 files at r1.
Reviewable status: 4 of 5 files reviewed, 1 unresolved discussion (waiting on @meship-starkware, @PearsonWhite, and @rodrigo-pino)

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crates/blockifier/src/execution/native/utils.rs line 34 at r7 (raw file):

Previously, PearsonWhite wrote…

I don't think this will match unicode 0s. I can't reproduce an error with the test string "Not supporting Cairo 0" in "test_encode_decode_str".

You are right :)

[meship-starkware]

Reviewed all commit messages.
Reviewable status: 4 of 5 files reviewed, 1 unresolved discussion (waiting on @PearsonWhite and @rodrigo-pino)

[meship-starkware]

Reviewable status: 4 of 5 files reviewed, 1 unresolved discussion (waiting on @PearsonWhite and @rodrigo-pino)

[meship-starkware]

Reviewed 1 of 1 files at r5.
Reviewable status: 4 of 5 files reviewed, all discussions resolved (waiting on @PearsonWhite)

[meship-starkware]

Reviewed 1 of 1 files at r7.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @PearsonWhite)