review-pr

# libuipc PR Review ## Architecture primer (read before reviewing) libuipc is a GPU-accelerated Incremental Potential Contact (IPC) simulation library (C++20 + optional Python/pybind11). **Layer split:** | Layer | Path | Role | |-------|------|------| | Core | `src/core/`, `include/uipc/` | Engine lifecycle, Scene/World, geometry attribute ECS | | Geometry | `src/geometry/` | Mesh algorithms; libigl, TBB, Octree, embedded C++ METIS | | Constitution | `src/constitution/` | Material / constraint implementations | | I/O | `src/io/` | Scene + mesh serialisation | | Sanity check | `src/sanity_check/` | Pre-sim scene validation | | Backends | `src/backends/<name>/` | Physics engines as runtime-loaded **MODULE** DLLs | | Pybind | `src/pybind/` | Thin pybind11 wrapper; mirrors C++ submodules | **Backend plugin ABI** (`src/backends/common/module.h`): - Exports: `uipc_init_module`, `uipc_create_engine`, `uipc_destroy_engine` - Base classes: `SimEngine` → `ISimSystem` → subsystem folders (`affine_body/`, `finite_element/`, `contact_system/`, `collision_detection/`, etc.) - RMR (Reporter–Manager–Receiver) data-oriented design; avoid heavy OOP in backend code **CUDA backend subsystems** (most review-sensitive): `affine_body/`, `finite_element/`, `contact_system/`, `collision_detection/`, `distance_system/`, `active_set_system/`, `inter_primitive_effect_system/`, `engine/` (Newton + augmented-Lagrangian step in `advance_al.cu`) ## Workflow ### 1. Checkout and fetch metadata ```bash gh pr checkout <PR_NUMBER> gh pr view <PR_NUMBER> --json title,body,author,baseRefName,headRefName,headRefOid,repository,url,additions,deletions,changedFiles gh pr diff <PR_NUMBER> --name-only ``` ### 2. Present summary to the human reviewer ``` ## PR #<N>: <title> Author: <author> Branch: `<head>` → `<base>` URL: <url> Stats: +<add> / -<del> across <N> files ### Description <body> ### Files to review (grouped by subsystem) #### Backend — CUDA physics src/backends/cuda/affine_body/... src/backends/cuda/finite_element/... ... #### Core / Public API include/uipc/... src/core/... #### Geometry / Constitution src/geometry/... src/constitution/... #### Python bindings src/pybind/... python/src/uipc/... #### Build / CMake CMakeLists.txt src/backends/.../CMakeLists.txt #### Tests apps/tests/... python/tests/... ``` ### 3. AI review — libuipc-specific checklist Run `gh pr diff <PR_NUMBER>` and check every area below that is touched. --- #### Fast fail - [ ] All expected internal invariants are checked with `UIPC_ASSERT` where feasible - [ ] All user-facing inputs are validated with `UIPC_ASSERT_THROW` #### C++20 style - [ ] C-style code is forbidden unless unavoidable (e.g., DLL export signatures) - [ ] Raw pointer parameters are forbidden unless unavoidable; prefer `span<T>` - [ ] `const std::string&` parameters are forbidden; use `std::string_view` instead - [ ] Multiple inheritance is forbidden; separate concerns into distinct classes #### CUDA / GPU code - [ ] GPU buffer arguments use `muda::BufferView` / `muda::TripletMatrixView` (or equivalent view types) instead of raw pointers - [ ] Raw pointer parameters are forbidden in device code unless unavoidable #### Constitution / material - [ ] New constitutions implement required `IConstitution`-family interface - [ ] Material parameters validated / clamped (no negative stiffness, density, etc.) #### Public C++ API (`include/uipc/`) - [ ] No breaking changes to public headers without a version bump or deprecation notice - [ ] New public classes/functions follow existing naming: `CamelCase` types, `snake_case` functions, `m_` prefix for members - [ ] `#pragma once` present; no `<windows.h>`-style global macros leaked #### C++ style (`.clang-format` enforced) - [ ] 4-space indent, 80-column limit - [ ] Allman braces (`{` on its own line) - [ ] Left-aligned pointers (`int* p`, not `int *p`) - [ ] No `using namespace std;` in headers #### CMake - [ ] New backend follows `uipc_add_backend(name)` macro in `src/backends/CMakeLists.txt` - [ ] New CMake options added to the root `CMakeLists.txt` option block with sensible defaults - [ ] `file(GLOB ...)` patterns extended if new source subdirs added #### Python bindings (`src/pybind/` + `python/`) - [ ] Check whether new features expose a public API that should be mirrored in the Python bindings - [ ] New C++ types exposed via matching pybind submodule (mirrors C++ namespace) - [ ] `__init__.py` import chain not broken (`pyuipc` → `init()` → `config["module_dir"]`) - [ ] Python-side tests added under `python/tests/` for new pybind surface #### Tests - [ ] C++ tests use Catch2 macros; added via `uipc_add_test` in the appropriate `apps/tests/<subsystem>/CMakeLists.txt` - [ ] Regression tests added for bug fixes --- ### 4. Output format Each finding must have a **sequential number** (1, 2, 3 … across all severity tiers) and a **clickable local file link** constructed from the absolute repo path + relative file path. Use this markdown link format for every citation: ``` [filename.ext:LINE](ABSOLUTE_REPO_PATH/relative/path/to/file.ext) ``` For example, if the repo is at `/home/user/libuipc` and the file is `src/backends/cuda/affine_body/foo.cu` at line 42: ``` [foo.cu:42](/home/user/libuipc/src/backends/cuda/affine_body/foo.cu) ``` Full output template: ``` ## AI Review — PR #<N> ### Summary of changes <one paragraph> ### Findings 🔴 Critical (must fix) **#1** — [filename.ext:LINE](ABSOLUTE_PATH/relative/path/filename.ext) Description of the issue and why it matters. **#2** — [filename.ext:LINE](ABSOLUTE_PATH/relative/path/filename.ext) Description. 🟡 Suggestion **#3** — [filename.ext:LINE](ABSOLUTE_PATH/relative/path/filename.ext) Description. 🟢 Nice-to-have **#4** — [filename.ext:LINE](ABSOLUTE_PATH/relative/path/filename.ext) Description. ### Checklist coverage (tick the items above that were verified or N/A) ``` --- ### 5. Post comments via `gh` (when asked) **General review comment / request changes / approve:** ```bash gh pr review <PR_NUMBER> --comment --body "..." gh pr review <PR_NUMBER> --request-changes --body "..." gh pr review <PR_NUMBER> --approve --body "LGTM" ``` **Inline comment on a specific line:** ```bash gh api repos/<OWNER>/<REPO>/pulls/<PR_NUMBER>/comments \ --method POST \ -f path="<FILE_PATH>" \ -f body="Your comment" \ -F line=<LINE_NUMBER> \ -f side="RIGHT" \ -f commit_id="<HEAD_REF_OID>" ``` Run `gh auth status` first if commands fail.