# Repository Guidelines

## Project Structure & Module Organization

`libakstdlib` is a C shared library that wraps libc calls and small data
structures in `libakerror` error contexts. Public API declarations live in
`include/akstdlib.h`; implementation lives in `src/stdlib.c`. Tests are
one-file CTest executables under `tests/test_<name>.c`, with shared test helpers
in `tests/aksl_capture.h`. CMake package templates are in `cmake/` and
`akstdlib.pc.in`. The vendored dependency is `deps/libakerror`; update it as a
submodule rather than editing generated files under `build/`, `build-asan/` or
`build-coverage/`.

## Build, Test, and Development Commands

Initialize dependencies before a fresh build:

```sh
git submodule update --init --recursive
cmake -S . -B build
cmake --build build
```

Run the normal suite with `ctest --test-dir build --output-on-failure`. Use the
instrumented build for memory and undefined-behavior checks:

```sh
cmake -S . -B build-asan -DAKSL_SANITIZE=ON
cmake --build build-asan
ctest --test-dir build-asan --output-on-failure
```

For coverage, configure a third tree; the report is part of that suite (the
`coverage_reset` / `coverage_report` CTest entries) and also lands in
`build-coverage/coverage-summary.txt`:

```sh
cmake -S . -B build-coverage -DAKSL_COVERAGE=ON
cmake --build build-coverage --target coverage
```

Run `cmake --build build --target mutation` only when you need the slower
mutation harness. `rebuild.sh` installs to `/home/andrew/local` and removes the
local build directory, so treat it as a local convenience script.

## Coding Style & Naming Conventions

Use C with 4-space indentation; existing files sometimes use tabs for continued
statements, so match the surrounding block. Public symbols use the `aksl_`
prefix, structs use `aksl_<Name>`, and tests use `test_<feature>.c` plus static
`test_<case>` functions. Preserve the `akerr_ErrorContext AKERR_NOIGNORE *`
return convention and the `PREPARE_ERROR` / `FAIL_*` / `SUCCEED_RETURN` pattern.

## Testing Guidelines

Add a new test by creating `tests/test_mything.c` and adding `mything` to the
right list in `CMakeLists.txt`. `AKSL_TESTS` must exit zero.
`AKSL_WILL_FAIL_TESTS` are deliberate abort/contract tests.
`AKSL_KNOWN_FAILING_TESTS` assert documented defects from `TODO.md`; when one
starts unexpectedly passing, move it into `AKSL_TESTS` with the fix.

`src/stdlib.c` is at 99.1% line coverage and CI gates it at 90 (line) / 40
(branch), so new code needs tests in the same commit. Run
`cmake --build build-coverage --target coverage` and check the uncovered-line
listing before proposing a change. Tests for behaviour that `TODO.md` records as
defective belong in `AKSL_KNOWN_FAILING_TESTS` asserting the *correct* contract —
do not pin current-but-wrong behaviour in `AKSL_TESTS`, since that turns the
eventual fix into a test failure.

## Commit & Pull Request Guidelines

Recent commits use short imperative summaries, for example `Add memory wrapper
tests` and `Make error-status assertions authoritative`. Keep commits focused
and include tests with behavior changes. Pull requests should describe the
changed API or behavior, list the CTest/sanitizer/mutation commands run, and
link the relevant `TODO.md` item or issue when fixing a known defect.

## Agent-Specific Instructions

Do not modify generated build trees, profiling artifacts, or untracked scratch
files unless explicitly asked. Prefer small, test-backed changes and update
`README.md` or `TODO.md` when changing documented workflows or known failures.