Dual Contract Builds with Optional Logging

[liuchengxu]

Summary

To balance development experience and on-chain performance, I propose maintaining two variants of our CosmWasm contracts:

• Development Version: Logging enabled for better debugging and observability.
• Production Version: Logging stripped out to reduce on-chain WASM overhead.

WASM logging incurs non-negligible execution costs, which makes a logging-free build preferable for production deployments. This issue tracks the design and implementation of tooling and workflows to support this approach.

Tasks

• Created cosmwasm-logging Crate

  • Standard Rust log crate integration with CosmWasm's api.debug()
  • Zero-cost production builds using conditional compilation
  • Custom logger that formats output as target: [LEVEL] message

• Contract Integration

  • Feature-Based Build System

    • logging feature: Full logging with log crate dependency
    • No features (default): No-op macros, zero runtime cost, no log dependency
    • Organized code structure with enabled/disabled modules

  • Dual-Build Integration

    • Configured via [package.metadata.optimizer] in Cargo.toml
      • Production: babylon_contract.wasm (no logging)
      • Development: babylon_contract-dev.wasm (full logging)

  • Added logging to contracts with structured targets

  • Called init_cosmwasm_logger() in all entry points: instantiate(), execute(), query(), reply(), migrate(), ensuring logging works in all unit tests regardless of entry point

• Update babylon-sdk to use the dev version of contracts so that we can have the proper logging in development. We should integrate the logging into the rollup-bsn-contracts once everything goes well.

Optionally, we can support automated size/gas/cost comparison between the two builds.