[pallet-revive] Execution tracer

[pgherveou]

This PR introduces a Geth-compatible execution tracer (StructLogger) for pallet-revive

The tracer can be used to capture both EVM opcode and PVM syscall.
It can be used with the same RPC endpoint as Geth StructLogger.

Since it can be quite resource intensive, It can only be queried from the node when the DebugSettings are enabled (This is turned on now by default in the dev-node)

Tested in paritytech/evm-test-suite#138

example:

❯ cast rpc debug_traceTransaction "<TX_HASH>" | jq

# or with options
# See list of options https://geth.ethereum.org/docs/developers/evm-tracing/built-in-tracers#struct-opcode-logger

  ❯ cast rpc debug_traceTransaction "<TX_HASH>", { "tracer": { "enableMemory": true } } | jq

The response includes additional fields compared to the original Geth debug RPC endpoints:

For the trace:

• weight_consumed: same as gas but expressed in Weight
• base_call_weight: the base cost of the transaction

For each step:

• weight_cost: same as gas_cost but expressed in Weight

For an EVM execution, the output will look like this

{
  "gas": 4208049,
  "weight_consumed": { "ref_time": 126241470000, "proof_size": 4208 },
  "base_call_weight": { "ref_time": 9000000000, "proof_size": 3000 },
  "failed": false,
  "returnValue": "0x",
  "structLogs": [
    {
      "gas": 4109533,
      "gasCost": 3,
      "weight_cost": { "ref_time": 90000, "proof_size": 0 },
      "depth": 1,
      "pc": 0,
      "op": "PUSH1",
      "stack": []
    },
    {
      "gas": 4109530,
      "gasCost": 3,
      "weight_cost": { "ref_time": 90000, "proof_size": 0 },
      "depth": 1,
      "pc": 2,
      "op": "PUSH1",
      "stack": [
        "0x80"
      ]
    },
    {
      "gas": 4109527,
      "gasCost": 3,
      "weight_cost": { "ref_time": 90000, "proof_size": 0 },
      "depth": 1,
      "pc": 4,
      "op": "MSTORE",
      "stack": [
        "0x80",
        "0x40"
      ]
    }]
}

For PVM execution, each step includes additional fields not present in Geth:

• args: Array of syscall arguments (register values a0-a5) as hex strings
• returned: The syscall return value as hex string

These fields are enabled by default. To disable them, use disableSyscallDetails: true.

Example output with syscall details:

{
  "gas": 97108,
  "gasCost": 131,
  "weight_cost": { "ref_time": 3930000, "proof_size": 0 },
  "depth": 1,
  "op": "call_data_load",
  "args": ["0x0", "0x4"],
  "returned": "0x2a"
}

[xermicus]

The EVM trace also reports the stack which should be enough the reconstruct a full execution trace. But PVM missing the syscall arguments and return values makes this of limited use?

[pgherveou]

The EVM trace also reports the stack which should be enough the reconstruct a full execution trace. But PVM missing the syscall arguments and return values makes this of limited use?

true, I can add that in, wasn't planning on supporting pvm at first, but now that I do we better add the args you are right

[pgherveou]

/bot fmt

[marian-radu]

Looks good to me

[pgherveou]

/bot fmt

[paritytech-workflow-stopper]

All GitHub workflows were cancelled due to failure one of the required jobs.
Failed workflow url: https://github.com/paritytech/polkadot-sdk/actions/runs/21358429077
Failed job name: fmt