How to use config option fullTracer.printOpcodes in zkevm-proverjs

[mooori]

For benchmarking of NEAR’s ZK WASM I’m trying to make zkevm-proverjs print opcodes using fulltracer.printOpcodes. This script triggers execution and I’m using the following config:

const config = {
    debug: true,
    debugInfo: {
        inputName: path.basename(pathTest),
    },
    tracer: true,
    stepsN: 8388608,
    assertOutputs: false,
    verboseOptions: {
        fulltracer: {
            enable: true,
            enableOpcodes: true,
            printOpcodes: true,
            bytecode: true,
            outputs: true,
            saveOutputs: true
        }
    }
};

Tracer objects are constructed but onOpcode isn’t called

By manual debugging I could check that both FullTracer and VerboseTracer are constructed. However onOpcode (which should print the opcode) is not called.

Possible issues

• Some other steps are needed to emit onOpcode events?
• Is printOpcodes used in a wrong location?
• Is there other configuration that needs to be enabled to make printOpcodes work?
• Are logs written but I just cannot find them?
  • I would assume that’s rather not the problem as I inserted logs into zkevm-proverjs to print the directory where logs should be written. After execution these directories are empty.

Smoke test: stats: true

This works for me. When adding stats: true to above config, data is written to node_modules/0xpolygonhermez/zkevm-proverjs/src/sm/sm_main/logs-stats/*.json.

Branch feature/64bits

Note that near/wasmtime uses branch feature/64bits of zkevm-proverjs.

[krlosMata]

hi !!

Brief explanation of modules:

• fullTracer: Class to get execution traces of the batch execution. Heavily focus to get EVM traces like geth does for Ethereum. It is like an EVM trace extended wverboseOptionsith some zkEVM parameters
• verboseOptions: property of the config. Useful to print data on the terminal (or save data) that is collected by the fullTracer. Very useful to debug without doing breakpoints.

Enable fullTracer

• main_executor.js should be run with the -T flag: https://github.com/0xPolygonHermez/zkevm-proverjs/blob/feature/64bits/src/main_executor.js#L35
  • note that fullTracer has not been ported to 64 bits registers
• fullTracer works by triggering its events (eventLog) from the .zkasm code: https://github.com/0xPolygonHermez/zkevm-rom/blob/main/main/process-tx.zkasm#L381
  • this basically means that every time this line of the .zkasm is triggered --> the sm_main calls the fullTracer to that specific function --> https://github.com/0xPolygonHermez/zkevm-proverjs/blob/feature/64bits/src/sm/sm_main/sm_main_exec.js#L1753
    • then, inside the fullTracert --> the onOpcode is called
    • inside the onOpcode all the necessary data is collected to create the EVM execution trace opcode step
      • note that all the data collected depends heavily on the .zkasm variables defined

Suggestion

• take the fullTracer class and add a new function like onOpcode64
• in the .zkasm add the necessary event $${eventLog(onOpcode64())}
• collect necessary data in the fullTracer function

hope it helps xD