Files
libakstdlib/AGENTS.md
Andrew Kesterson 125eeb2109 Version at 0.2.0: complete the wishlist, document it, gate the docs
Closes what was left of TODO.md sections 1, 2 and 3, and rewrites that
file to hold outstanding items only.

The API break gets a minor bump, because pre-1.0 the soname carries
MAJOR.MINOR and 0.1 and 0.2 are therefore different ABIs. Five
signatures changed and the ato* contract with them; UPGRADING.md is new
and lists every one, with the before/after for the cases the compiler
cannot warn about.

Section 3.1 is finished: reallocarray with the multiplication checked,
aligned_alloc and posix_memalign, asprintf/vasprintf, scanf/vscanf.
Four functions on that list are deliberately absent rather than missing
-- sprintf, strtok, setbuf and perror -- and TODO.md now says which and
why, so nobody adds them thinking they were forgotten.

Section 1.9, the cross-cutting tests:

  tests/test_pool.c    drives every failure path AKERR_MAX_ARRAY_ERROR
                       + 10 times and checks the pool after each round,
                       because a wrapper that leaks a slot fails a
                       hundred calls later in unrelated code. It also
                       asserts that each error names the function and
                       file it was raised from, which is what catches a
                       FAIL that migrates into a helper during a
                       refactor: status right, message right, origin
                       quietly lying.
  tests/negative/      two sources that must FAIL to compile, built with
                       -Werror and registered WILL_FAIL. AKERR_NOIGNORE
                       and the format attributes are enforced by the
                       compiler and by nothing else; drop either and
                       every ordinary test still passes.

Thread safety is answered rather than tested: the library is not
thread-safe and cannot be made so from here, because libakerror's error
pool is an unlocked process-global array. README.md says so plainly and
TODO.md carries it as the item blocking any future pthread wrappers.

Doxygen is configured and gated. All 147 public functions have @brief,
a @param each, @throws per status and @return; EXTRACT_ALL is off and
WARN_NO_PARAMDOC on, so `cmake --build build --target docs` fails on an
undocumented entity. It ran to 0 warnings. The Doxyfile carries no
version -- cmake/RunDoxygen.cmake feeds PROJECT_NUMBER in from
project(), so that stays the one place a version is written.

CI now builds against the submodule it pins instead of also installing
libakerror@main and never linking it, adds -Werror, and gains a
sanitizer job. The pre-push hook matches, and runs the docs check too.

Coverage: 99.5% of lines (1643/1651), 100% of functions (147/147). The
eight uncovered lines are each uncovered on purpose and TODO.md says
which and why.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 08:00:16 -04:00

6.0 KiB

Repository Guidelines

Project Structure & Module Organization

libakstdlib is a C shared library that wraps libc calls and data structures in libakerror error contexts.

Public API declarations live in include/akstdlib.h, which is also where the Doxygen documentation lives -- the header is the contract, the sources carry the reasoning. The implementation is split by domain:

File Covers
src/stdlib.c memory, formatted output, string-to-number, realpath, djb2, and the list/tree traversal entry points
src/string.c the string.h surface
src/stream.c stdio.h beyond open/read/write/close
src/collections.c list and tree operations, hash map, string buffer, FNV-1a
src/aksl_internal.h shared internals; not installed, not public

Tests are one-file CTest executables under tests/test_<name>.c, with shared helpers in tests/aksl_capture.h. tests/negative/ holds sources that must fail to compile -- see the testing section below. 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:

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:

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:

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, and cmake --build build --target docs to regenerate the API documentation -- that one fails if any public function, parameter or return value is undocumented, so it is a check as well as a generator.

.githooks/pre-push runs the default build, the sanitizer build and the documentation check before a push; enable it with git config core.hooksPath .githooks. 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.

Four conventions hold across the whole library, and a new wrapper that breaks one of them is wrong even if it compiles and passes:

  • A NULL out-param is a caller error, not "don't care".
  • Finding nothing is success -- searching functions write NULL or zero and return NULL.
  • Truncation is a failure. Take the destination's size, raise AKERR_OUTOFBOUNDS, and write nothing rather than a prefix.
  • Clear errno before the wrapped call and read it back through AKSL_ERRNO_OR, so no error can carry status 0 -- which every downstream DETECT reads as success.

Every new public function needs a Doxygen block on its declaration with @brief, a @param per parameter, a @throws per status it can raise, and @return. The docs target fails otherwise.

The build is -Wall -Wextra and CI adds -Werror. -Wpedantic is deliberately off: libakerror's FAIL_* macros trip "ISO C99 requires at least one argument for the ..." on their own expansion, not on anything at the call site.

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. Both of the latter are currently empty -- all six confirmed defects are fixed -- but the mechanism stays for the next one.

tests/negative/ holds sources that must fail to compile. Each is an EXCLUDE_FROM_ALL target built with -Werror and registered as a WILL_FAIL CTest entry, so the test passes only when the compile fails. They cover the two guarantees the compiler enforces and nothing else does: AKERR_NOIGNORE and the format attributes. Drop either in a refactor and every ordinary test still passes.

Coverage is 99.5% of lines and 100% of functions across all four sources; CI gates 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.