sanitizer-testing

name	sanitizer-testing
description	Build and test Reussir with ASan, LSan, MSan, or TSan, especially when validating generated LLVM IR against the Rust runtime allocator path and future multithreaded code.
license	MPL-2.0

Use this skill when the task is about sanitizer correctness, sanitizer-enabled test builds, or checking whether generated Reussir code interacts correctly with the runtime.

Standard Procedure

1. Keep the compiler and tools unsanitized. Build dedicated runtime variants instead:

   cmake -S . -B build-sanitizers -G Ninja \
     -DCMAKE_C_COMPILER=clang \
     -DCMAKE_CXX_COMPILER=clang++ \
     -DREUSSIR_ENABLE_TESTS=ON \
     -DREUSSIR_RUNTIME_SANITIZERS="address;leak;memory;thread"
   

2. Build the normal project plus the sanitizer runtimes:

   ninja -C build-sanitizers reussir-ut check check-sanitizer
   ctest --test-dir build-sanitizers --output-on-failure
   

3. For integration tests of generated Reussir programs, prefer this pipeline:

   %rrc input.rr -o %t.ll --emit llvm-ir ...
   %cc %asan_flags -c -x ir %t.ll -o %t.o
   %cc %asan_flags %t.o harness.c %reussir_rt_asan -o %t.exe \
     %rpath_flag %extra_sys_libs
   %asan_env %t.exe
   

   Replace asan with lsan, msan, or tsan as needed. This lets Clang instrument the generated LLVM IR while the runtime comes from a dedicated libreussir_rt.<san>.so build.

Reussir-Specific Rules

• Sanitized runtime builds must not use the runtime's custom global allocator. The runtime CMake rules build sanitizer variants with --no-default-features so ASan/LSan can see heap allocation and free events.
• Prefer check-sanitizer for sanitizer-specific lit cases under tests/integration/sanitizer/.

Accuracy Expectations

• address / leak: Accurate heap reports require the runtime allocator path to stay visible to compiler-rt. If allocator customization is reintroduced in sanitized runtime builds, expect heap-use-after-free and leak reports to become incomplete.
• memory: MSan requires all participating code to be instrumented. Reussir-generated LLVM IR and the Rust runtime can be instrumented, but external libraries and system runtimes may still limit report quality.
• thread: TSan does not need allocator-specific hooks for ordinary memory accesses, but future Reussir thread primitives or custom mutex/queue implementations must be annotated with ThreadSanitizer synchronization APIs such as __tsan_acquire, __tsan_release, or mutex annotations.

Test Patterns

• Add one leak-clean sample that either returns a scalar result or uses a known correct ownership handoff in the C harness.
• Add one negative leak sample that intentionally omits release and uses %not under REQUIRES: lsan.
• Reuse existing benchmark-like programs such as rbtree.rr and rbtree2.rr so sanitizer coverage stays close to realistic allocation and ownership patterns.