Enable C++ PPR Sampling

.clang-tidy

@@ -47,10 +47,10 @@ Checks: >
 # Warnings from headers outside the regex (PyTorch, pybind11, etc.) are suppressed
 # entirely and never reach WarningsAsErrors — so the large warning counts printed
 # by clang-tidy ("N warnings generated") are third-party noise that is silently
-# dropped. Only diagnostics in our own headers (.*/gigl/csrc/.*) are reported,
+# dropped. Only diagnostics in our own headers (.*/gigl-core/core/.*) are reported,
 # and those are treated as hard errors.
 WarningsAsErrors: '*'
-HeaderFilterRegex: '.*/gigl-core/csrc/.*'
+HeaderFilterRegex: '.*/gigl-core/core/.*'
 FormatStyle:     none
 # CheckOptions: per-check tuning parameters. Each entry configures a specific
 # option for an individual check, using the form:

.github/cloud_builder/run_command_on_active_checkout.yaml

@@ -3,7 +3,7 @@ substitutions:
 options:
   logging: CLOUD_LOGGING_ONLY
 steps:
-  - name: us-central1-docker.pkg.dev/external-snap-ci-github-gigl/gigl-base-images/gigl-builder:b598f3d72eee47f5513dcb39460944459a0a012f.108.1
+  - name: us-central1-docker.pkg.dev/external-snap-ci-github-gigl/gigl-base-images/gigl-builder:7d3182eeb6446ce3e35910babba990c8e003879d.109.1
     entrypoint: /bin/bash
     args:
       - -c

.github/workflows/release.yml

@@ -59,7 +59,7 @@ jobs:
       run: |
         # Remove stale cmake cache from previous runs on self-hosted runners.
         rm -rf gigl-core/.cache/cmake_build
-        uv build --wheel gigl-core/ --locked
+        uv build --wheel gigl-core/
 
     - name: Publish gigl-core wheel
       working-directory: gigl-core
@@ -73,5 +73,5 @@ jobs:
     # when gigl becomes available.
     - name: Build and publish gigl wheel
       run: |
-        uv build --wheel --locked
+        uv build --wheel
         uv publish --publish-url ${{ matrix.publish-url }} --username oauth2accesstoken --keyring-provider subprocess

Makefile

@@ -22,7 +22,7 @@ DOCKER_IMAGE_MAIN_CPU_NAME_WITH_TAG?=${DOCKER_IMAGE_MAIN_CPU_NAME}:${DATE}
 DOCKER_IMAGE_DEV_WORKBENCH_NAME_WITH_TAG?=${DOCKER_IMAGE_DEV_WORKBENCH_NAME}:${DATE}
 
 PYTHON_DIRS:=.github/scripts examples gigl tests snapchat scripts
-CPP_SOURCES:=$(shell find gigl-core/csrc \( -name "*.cpp" -o -name "*.cu" \) 2>/dev/null)
+CPP_SOURCES:=$(shell find gigl-core/core \( -name "*.cpp" -o -name "*.cu" \) 2>/dev/null)
 # clang-tidy 15 does not fully support CUDA syntax (e.g. <<<...>>>, __global__).
 # Exclude .cu files from tidy targets; clang-format and clangd handle them fine.
 CPP_SOURCES_NO_CUDA:=$(filter-out %.cu,$(CPP_SOURCES))
@@ -35,8 +35,8 @@ GIGL_E2E_TEST_COMPILED_PIPELINE_PATH:=/tmp/gigl/pipeline_${DATE}_${GIT_HASH}.yam
 
 GIT_BRANCH:=$(shell git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "")
 
-# Find all markdown files in the repo except for those in .venv or tools directories.
-MD_FILES := $(shell find . -type f -name "*.md" ! -path "*/.venv/*" ! -path "*/tools/*")
+# Find all markdown files in the repo except for those in .venv, tools, or cmake cache directories.
+MD_FILES := $(shell find . -type f -name "*.md" ! -path "*/.venv/*" ! -path "*/tools/*" ! -path "*/.cache/*")
 GIGL_ALERT_EMAILS?=""
 
 get_ver_hash:
@@ -165,20 +165,11 @@ type_check:
 build_cpp_extensions:
 	$(MAKE) -C gigl-core build_cpp_extensions
 
-check_lint_cpp: build_cpp_extensions
-	$(if $(CPP_SOURCES_NO_CUDA),uv run python -m scripts.run_cpp_lint $(CPP_SOURCES_NO_CUDA))
-
-# Not part of `make format`: clang-tidy --fix rewrites logic (renames identifiers,
-# changes expressions, adds/removes keywords), not just style. Run manually and
-# review the diff before committing. Note: --fix cannot auto-repair every check;
-# some violations require manual edits.
-# --extra-arg=-Wno-ignored-optimization-argument suppresses GCC-specific LTO flags
-# (-fno-fat-lto-objects, -flto=auto) that cmake writes into compile_commands.json.
-# clang-tidy forwards compiler warnings via clang-diagnostic-*, and .clang-tidy sets
-# WarningsAsErrors: '*', so the warning must be silenced at the compiler level before
-# clang-tidy ever sees it.
-fix_lint_cpp: build_cpp_extensions
-	$(if $(CPP_SOURCES_NO_CUDA),clang-tidy-15 --fix --extra-arg=-Wno-ignored-optimization-argument -p gigl-core/.cache/cmake_build/compile_commands.json $(CPP_SOURCES_NO_CUDA))
+check_lint_cpp:
+	$(MAKE) -C gigl-core check_lint_cpp
+
+fix_lint_cpp:
+	$(MAKE) -C gigl-core fix_lint_cpp
 
 lint_test: check_format assert_yaml_configs_parse check_lint_cpp
 	@echo "Lint checks pass!"

docs/cpp_style_guide.md

@@ -163,7 +163,7 @@ Enforced via `readability-identifier-naming`:
 | Option                                                     | Value                  | Effect                                                                                                                                                                                |
 | ---------------------------------------------------------- | ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `WarningsAsErrors`                                         | `*`                    | Every check failure is a hard error in CI                                                                                                                                             |
-| `HeaderFilterRegex`                                        | `.*/gigl-core/csrc/.*` | Scopes checks to our own headers. Using `.*` causes clang-tidy to report warnings from every PyTorch/pybind11 header it parses, flooding output with thousands of third-party issues. |
+| `HeaderFilterRegex`                                        | `.*/gigl-core/core/.*` | Scopes checks to our own headers. Using `.*` causes clang-tidy to report warnings from every PyTorch/pybind11 header it parses, flooding output with thousands of third-party issues. |
 | `FormatStyle`                                              | `none`                 | clang-tidy does not auto-reformat; use clang-format separately                                                                                                                        |
 | `bugprone-string-constructor.LargeLengthThreshold`         | `8388608` (8 MB)       | Strings larger than 8 MB from a length argument are flagged                                                                                                                           |
 | `modernize-loop-convert.NamingStyle`                       | `camelBack`            | Auto-generated loop variable names use camelBack, matching `readability-identifier-naming.VariableCase`                                                                               |
@@ -174,7 +174,7 @@ ______________________________________________________________________
 
 ## pybind11 Extension Modules
 
-Extension modules live under `gigl-core/csrc/`.
+Extension modules live under `gigl-core/core/`.
 
 ### Naming convention
 
@@ -184,11 +184,11 @@ Extension modules live under `gigl-core/csrc/`.
 | `<name>.cpp` / `<name>.cu` | Implementation — function and class definitions                  |
 | `<name>.h`                 | Declarations (function signatures, class definitions, constants) |
 
-Example: to add a `my_op` extension under `gigl-core/csrc/sampling/`:
+Example: to add a `my_op` extension under `gigl-core/core/sampling/`:
 
 ```
-gigl-core/csrc/sampling/python_my_op.cpp   ← pybind11 bindings
-gigl-core/csrc/sampling/my_op.cpp          ← implementation
+gigl-core/core/sampling/python_my_op.cpp   ← pybind11 bindings
+gigl-core/core/sampling/my_op.cpp          ← implementation
 ```
 
 The compiled `.so` is installed into the `gigl_core` package and importable as `gigl_core.<name>`.

gigl-core/.clangd

@@ -0,0 +1,5 @@
+# Point clangd at the test compilation database rather than the default cmake_build one.
+# The test database includes both the extension modules and the test binaries, so clangd
+# can resolve gtest headers for test files alongside production headers.
+CompileFlags:
+  CompilationDatabase: .cache/cpp_tests

gigl-core/CMakeLists.txt

@@ -26,19 +26,19 @@ endif()
 
 # ---------------------------------------------------------------------------
 # Extension modules — auto-discovered.
-# Files named python_*.cpp under csrc/ are compiled as pybind11 extension
+# Files named python_*.cpp under core/ are compiled as pybind11 extension
 # modules. The companion <name>.cpp (without the "python_" prefix) is included
 # automatically when present. Add a new extension by dropping source files
 # here; no changes to this CMakeLists.txt are needed.
 # ---------------------------------------------------------------------------
 if(CMAKE_CUDA_COMPILER)
     file(GLOB_RECURSE _PYTHON_SRCS CONFIGURE_DEPENDS
-        "${CMAKE_CURRENT_SOURCE_DIR}/csrc/python_*.cpp"
-        "${CMAKE_CURRENT_SOURCE_DIR}/csrc/python_*.cu"
+        "${CMAKE_CURRENT_SOURCE_DIR}/core/python_*.cpp"
+        "${CMAKE_CURRENT_SOURCE_DIR}/core/python_*.cu"
     )
 else()
     file(GLOB_RECURSE _PYTHON_SRCS CONFIGURE_DEPENDS
-        "${CMAKE_CURRENT_SOURCE_DIR}/csrc/python_*.cpp"
+        "${CMAKE_CURRENT_SOURCE_DIR}/core/python_*.cpp"
     )
 endif()
 

gigl-core/Makefile

@@ -2,7 +2,7 @@
 # Invoked from the GiGL repo root via: $(MAKE) -C gigl-core <target>
 # All paths below are relative to gigl-core/.
 
-CPP_SOURCES := $(shell find csrc \( -name "*.cpp" -o -name "*.cu" \) 2>/dev/null)
+CPP_SOURCES := $(shell find core \( -name "*.cpp" -o -name "*.cu" \) 2>/dev/null)
 # clang-tidy 15 does not fully support CUDA syntax (e.g. <<<...>>>, __global__).
 # Exclude .cu files from tidy targets; clang-format and clangd handle them fine.
 CPP_SOURCES_NO_CUDA := $(filter-out %.cu,$(CPP_SOURCES))
@@ -12,10 +12,12 @@ CPP_SOURCES_NO_CUDA := $(filter-out %.cu,$(CPP_SOURCES))
 # pyproject.toml, make skips the reinstall unless something actually changed.
 # We cd to the repo root so that no-build-isolation-package in the root pyproject.toml
 # is respected by uv pip install.
-.cache/cmake_build/CMakeInit.txt: $(shell find csrc \( -name '*.cpp' -o -name '*.cu' -o -name '*.h' -o -name '*.cuh' \) 2>/dev/null) CMakeLists.txt pyproject.toml
+.cache/cmake_build/CMakeInit.txt: $(shell find core \( -name '*.cpp' -o -name '*.cu' -o -name '*.h' -o -name '*.cuh' \) 2>/dev/null) CMakeLists.txt pyproject.toml
 	cd $(abspath $(CURDIR)/..) && uv pip install -e gigl-core/
 
-build_cpp_extensions: .cache/cmake_build/CMakeInit.txt
+# Also depend on the test cmake configure so that .cache/cpp_tests/compile_commands.json
+# is generated automatically, giving clangd visibility into test files and gtest headers.
+build_cpp_extensions: .cache/cmake_build/CMakeInit.txt .cache/cpp_tests/.configured
 
 .cache/cpp_tests/.configured: CMakeLists.txt tests/CMakeLists.txt .cache/cmake_build/CMakeInit.txt
 	cmake -C .cache/cmake_build/CMakeInit.txt -S . -B .cache/cpp_tests -DGIGL_CORE_BUILD_TESTS=ON
@@ -25,13 +27,26 @@ unit_test_cpp: .cache/cpp_tests/.configured
 	cmake --build .cache/cpp_tests --parallel
 	ctest --test-dir .cache/cpp_tests --output-on-failure
 
-# TODO: Remove the $(if ...) guards once C++ source files are permanently present in the
-# repo. The guards exist to silently no-op on branches that have no python_*.cpp files yet.
 check_format_cpp:
-	$(if $(CPP_SOURCES),clang-format-15 --dry-run --Werror --style=file $(CPP_SOURCES))
+	clang-format-15 --dry-run --Werror --style=file $(CPP_SOURCES)
 
 format_cpp:
-	$(if $(CPP_SOURCES),clang-format-15 -i --style=file $(CPP_SOURCES))
+	clang-format-15 -i --style=file $(CPP_SOURCES)
+
+# Not part of `make format`: clang-tidy --fix rewrites logic (renames identifiers,
+# changes expressions, adds/removes keywords), not just style. Run manually and
+# review the diff before committing. Note: --fix cannot auto-repair every check;
+# some violations require manual edits.
+# --extra-arg=-Wno-ignored-optimization-argument suppresses GCC-specific LTO flags
+# (-fno-fat-lto-objects, -flto=auto) that cmake writes into compile_commands.json.
+# clang-tidy forwards compiler warnings via clang-diagnostic-*, and .clang-tidy sets
+# WarningsAsErrors: '*', so the warning must be silenced at the compiler level before
+# clang-tidy ever sees it.
+check_lint_cpp: build_cpp_extensions
+	cd $(abspath $(CURDIR)/..) && uv run python gigl-core/scripts/run_cpp_lint.py $(addprefix gigl-core/,$(CPP_SOURCES_NO_CUDA))
+
+fix_lint_cpp: build_cpp_extensions
+	clang-tidy-15 --fix --extra-arg=-Wno-ignored-optimization-argument -p .cache/cmake_build/compile_commands.json $(CPP_SOURCES_NO_CUDA)
 
 # Wipe cmake build caches. Use this if cmake's cached state becomes inconsistent
 # after switching between branches with substantially different CMakeLists.txt structure.
@@ -43,4 +58,4 @@ clean_build_files_cpp:
 
 # Declare targets as phony so make always runs their recipes, even if a file or
 # directory with the same name happens to exist on disk.
-.PHONY: build_cpp_extensions unit_test_cpp check_format_cpp format_cpp clean_cpp clean_build_files_cpp
+.PHONY: build_cpp_extensions unit_test_cpp check_format_cpp format_cpp check_lint_cpp fix_lint_cpp clean_cpp clean_build_files_cpp