starknet_os: os resources test - remove all fee transfer syscalls

[dorimedini-starkware]

No description provided.

[dorimedini-starkware]

• starknet_os: os resources test - add send_message_to_l1 #14143 : 2 dependent PRs (#14144 , #14153 )
• starknet_os: os resources test - add replace_class #14142
• starknet_os: os resources test - support virtual builtins, add sha256 #14141
• starknet_os: define sha256 batch resources constants #14140
• starknet_os: os resources test - add keccak #14139
• starknet_os: os resources test - add 3 more syscalls #14138
• starknet_os: os resources test - remove all fee transfer syscalls #14137 👈 (View in Graphite)
• starknet_os: os resources test - add emit event #14136
• starknet_os: os resources test - add meta tx #14135
• starknet_os: os resources test - measure linear factor, add deploy #14134
• starknet_os: os resources test - library call #14129
• starknet_os: initial test, measure call contract resources #14128
• blockifier_test_utils: add option to deploy from zero in test accounts #14258
• starknet_os_flow_tests: helper function to declare explicit classes #14257
• starknet_os: os resources test - create fixed deployable account #14173
• main

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[reviewable-StarkWare]

This change is 

[cursor]

PR Summary

Low Risk
Changes are limited to test contracts and OS resource measurement helpers; no production execution or fee logic is modified.

Overview
Improves OS syscall resource measurement by treating the fee-transfer tail of each measurement transaction as a fixed, known syscall sequence instead of ad-hoc trimming.

The OS resources test contract’s __execute__ now no-ops when both calldata args are zero, so an invoke can exercise only account fee transfer without running the syscall benchmark loop.

In os_resources_test.rs, a FEE_TRANSFER_SYSCALLS constant documents the 10 syscalls emitted during fee transfer. A new test_fee_transfer_syscalls regression runs a zero-calldata invoke and asserts the trace matches that list. The main test_os_resources_regression path splits off the last 10 syscall traces, asserts they match FEE_TRANSFER_SYSCALLS, and measures only the remaining syscalls—replacing the previous approach of popping the last EmitEvent and filtering UNMEASURABLE_SYSCALLS during iteration.

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[yoavGrs]

@yoavGrs made 3 comments.
Reviewable status: 0 of 1 files reviewed, 4 unresolved discussions (waiting on dorimedini-starkware).

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crates/starknet_os_flow_tests/src/os_resources_test.rs line 121 at r3 (raw file):

///    the measurements, we use a stable dummy contract (that is not recompiled when the Cairo1
///    compiler's version changes), and we set the `deploy_from_zero` flag to `true` to make sure
///    changes in the deploying contract address are not reflected in the measurements.

Move this doc down.
Doc this new test.

Code quote:

/// Measure the OS overhead for each syscall, and compare the results with the latest VC.
///
/// This test relies on the [starknet_os::hint_processor::os_logger::OsLogger] to capture the
/// resources used by the OS when running a syscall. A "checkpoint" is made before entering a
/// syscall implementation, and after the syscall execution returns, the difference between the two
/// is stored in the logger's traces.
///
/// Some notes about these measurements:
/// 1. Some syscalls incur inner calls ([Selector::CallContract], for example). The resources
///    consumed by the inner logic must be subtracted from the measured overhead to get the actual
///    OS overhead.
/// 2. Some syscalls incur overhead that depends linearly on the length of the input to the syscall.
///    In these cases, the measuring contract calls the syscall twice in a row, the second call
///    having "one more" input than the first call; subtracting the sequential measurements gives
///    the linear factor of the syscall. One caveat here is that the linear factor of
///    [Selector::Keccak] is stored as a separate syscall cost ([Selector::KeccakRound]).
/// 3. The SHA family syscalls are implemented as "virtual builtins": the syscall execution only
///    pushes the inputs to a special memory segment, and the "heavy lifting" is done later. This
///    means that the overhead of the syscall is not captured by the `OsLogger`. These syscalls have
///    separate tests to measure their overhead.
/// 4. The [Selector::Deploy] syscall's overhead depends on the deployed contract address in a non-
///    trivial way (see the `normalize_address` function in the cairo-lang core). To avoid noise in
///    the measurements, we use a stable dummy contract (that is not recompiled when the Cairo1
///    compiler's version changes), and we set the `deploy_from_zero` flag to `true` to make sure
///    changes in the deploying contract address are not reflected in the measurements.

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crates/starknet_os_flow_tests/src/os_resources_test.rs line 275 at r3 (raw file):

    let all_syscalls = test_output.runner_output.txs_trace.last().unwrap().get_syscalls().clone();
    let (syscall_traces, fee_transfer_syscall_traces) =
        all_syscalls.split_at(all_syscalls.len() - FEE_TRANSFER_SYSCALLS.len());

Consider splitting the iterator (take / skip) instead of the syscalls vector.
non-blocking

Code quote:

    let all_syscalls = test_output.runner_output.txs_trace.last().unwrap().get_syscalls().clone();
    let (syscall_traces, fee_transfer_syscall_traces) =
        all_syscalls.split_at(all_syscalls.len() - FEE_TRANSFER_SYSCALLS.len());

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crates/starknet_os_flow_tests/src/os_resources_test.rs line 360 at r3 (raw file):

    // Make sure there are no more dangling syscalls.
    let dangling_syscall = syscalls_iter.next();

How can it happen after while let Some(syscall_trace) = syscalls_iter.next()?

Code quote:

    // Make sure there are no more dangling syscalls.
    let dangling_syscall = syscalls_iter.next();

[dorimedini-starkware]

@dorimedini-starkware made 4 comments.
Reviewable status: 0 of 1 files reviewed, 4 unresolved discussions (waiting on dorimedini-starkware, yoavGrs, and Yoni-Starkware).

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crates/starknet_os_flow_tests/src/os_resources_test.rs line 80 at r2 (raw file):

Previously, Yoni-Starkware (Yoni) wrote…

You can run this tx with trivial fee bounds and make this test a bit cleaner

I don't want to break if for some reason we want to avoid trivial resource bounds... we need to override the VC already to run in cairo-steps mode, I can imagine a scenario in which we will no longer allow "free" txs in cairo-steps mode. the current way adds more code but it is closer to a "real flow"

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crates/starknet_os_flow_tests/src/os_resources_test.rs line 121 at r3 (raw file):

Previously, yoavGrs wrote…

Move this doc down.
Doc this new test.

Done.

---

crates/starknet_os_flow_tests/src/os_resources_test.rs line 275 at r3 (raw file):

Previously, yoavGrs wrote…

Consider splitting the iterator (take / skip) instead of the syscalls vector.
non-blocking

what is the benefit? I want to verify the second part is equal to the expected fee-transfer syscalls, and iterate over the first part

---

crates/starknet_os_flow_tests/src/os_resources_test.rs line 360 at r3 (raw file):

Previously, yoavGrs wrote…

How can it happen after while let Some(syscall_trace) = syscalls_iter.next()?

can't, leftover code. thanks

[yoavGrs]

@yoavGrs reviewed 1 file and all commit messages, made 1 comment, and resolved 3 discussions.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on Yoni-Starkware).

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crates/starknet_os_flow_tests/src/os_resources_test.rs line 275 at r3 (raw file):

Previously, dorimedini-starkware wrote…

what is the benefit? I want to verify the second part is equal to the expected fee-transfer syscalls, and iterate over the first part

Avoid cloning, but that's not important enough in tests

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[Yoni-Starkware]

@Yoni-Starkware reviewed 1 file and all commit messages, made 1 comment, and resolved 1 discussion.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on dorimedini-starkware).

[dorimedini-starkware]

@dorimedini-starkware resolved 1 discussion.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on dorimedini-starkware).

[dorimedini-starkware]

@dorimedini-starkware reviewed 2 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on dorimedini-starkware).