EWTS — Error and Warning Trapping System

EWTS is a multi-language logging framework for hydrologic modules running either within ngen or as standalone applications. It provides consistent log levels, module identity handling, environment-driven configuration, and a common bridge model across C, C++, Fortran, and Python.

Under ngen, EWTS routes log messages through the ngen integration layer so configuration, formatting, and output location are controlled centrally. In standalone mode, each runtime applies the same general policy while handling its own file output.

Repository purpose

This repository provides:

• runtime logging libraries for C, C++, Fortran, and Python
• the ngen integration bridge and logger implementation
• generated module constants and log-level definitions
• generator tooling that keeps constants synchronized across languages
• MkDocs content for user-facing documentation

Logging model summary

EWTS supports two execution contexts:

1. ngen-integrated logging

   • the ngen integration layer owns configuration and output policy
   • logging configuration is read from ngen_logging.json
   • output is written beneath NGEN_RESULTS_DIR/logs/
   • files are generated per MPI rank
   • output can be unified or split by module

2. Standalone runtime logging

   • each language runtime writes its own log output
   • runtime behavior is controlled by environment variables such as EWTS_ENABLED, EWTS_LOG_LEVEL, and EWTS_LOG_DIR
   • output falls back through EWTS_LOG_DIR, $HOME/run_logs, and ./run_logs

Repository layout

runtime/
  c/          C Runtime Library
  cpp/        C++ Runtime Library
  fortran/    Fortran Runtime Library
  python/     Python package
integrations/
  ngen/       ngen bridge and logger integration
spec/
  module_registry.yaml
  log_levels.json
tools/
  generate_language_constants.py
docs/         MkDocs source

Build from the repository root

cmake -B cmake_buld -S . -DCMAKE_BUILD_TYPE=Release -DEWTS_WITH_NGEN=ON -DEWTS_BUILD_SHARED=ON
cmake --build cmake_buld -j

The top-level build compiles the native language-specific Runtime Libraries and builds the Python package.

Install

cmake --install cmake_buld --prefix /path/to/install

The install tree includes:

• C Runtime Library and headers
• C++ Runtime Library and headers
• Fortran Runtime Library and module files
• generated constants for supported languages
• ngen integration library when enabled
• CMake package configuration files
• Python wheel output from the top-level build

Python runtime development

For direct Python development:

pip install -e runtime/python/ewts

To build a wheel manually:

python -m cmake_buld runtime/python/ewts

Generated constants

EWTS uses specification files as the single source of truth for module metadata and log levels:

• spec/module_registry.yaml
• spec/log_levels.json

Regenerate language-specific constants with:

python tools/generate_language_constants.py

Generated files should be treated as derived artifacts and should not be edited by hand.

Documentation split

This repository uses two documentation audiences:

• docs/ contains user-facing MkDocs content intended to explain the framework, runtime behavior, and integration model.
• directory-local README.md files contain developer-facing documentation intended for contributors working in that part of the repository.

Developer entry points

For implementation details, start with:

• runtime/c/README.md
• runtime/cpp/README.md
• runtime/fortran/README.md
• runtime/python/README.md
• integrations/ngen/README.md
• tools/README.md