fix: add cmake subproject integration check

.github/workflows/03-macos-linux-build.yml

@@ -107,6 +107,35 @@ jobs:
             setuptools_scm
         shell: bash       
 
+      - name: Check CMake subproject integration
+        if: matrix.platform == 'linux-x64'
+        run: |
+          SMOKE_SOURCE="$RUNNER_TEMP/zvec-subproject-smoke"
+          SMOKE_BUILD="$RUNNER_TEMP/zvec-subproject-build"
+
+          mkdir -p "$SMOKE_SOURCE" "$SMOKE_BUILD"
+          cat > "$SMOKE_SOURCE/CMakeLists.txt" <<'EOF'
+          cmake_minimum_required(VERSION 3.13)
+          project(zvec_subproject_smoke LANGUAGES C CXX)
+
+          if(NOT ZVEC_SOURCE_DIR)
+            message(FATAL_ERROR "ZVEC_SOURCE_DIR is required")
+          endif()
+
+          add_subdirectory("${ZVEC_SOURCE_DIR}" zvec)
+          EOF
+
+          cmake -S "$SMOKE_SOURCE" -B "$SMOKE_BUILD" -G Ninja \
+            -DZVEC_SOURCE_DIR="$GITHUB_WORKSPACE" \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DBUILD_TOOLS=OFF \
+            -DBUILD_C_BINDINGS=OFF \
+            -DBUILD_PYTHON_BINDINGS=OFF \
+            -DENABLE_WERROR=ON \
+            -DCMAKE_C_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_CXX_COMPILER_LAUNCHER=ccache
+        shell: bash
+
       - name: Build from source
         run: |
           cd "$GITHUB_WORKSPACE"

src/core/algorithm/diskann/CMakeLists.txt

@@ -1,4 +1,4 @@
-include(${CMAKE_SOURCE_DIR}/cmake/bazel.cmake)
+include(${PROJECT_ROOT_DIR}/cmake/bazel.cmake)
 
 file(GLOB_RECURSE ALL_SRCS *.cc *.c)
 
@@ -54,4 +54,4 @@ endif()
 # as an optional plugin that users load at runtime via zvec::LoadDiskAnnPlugin().
 set_target_properties(core_knn_diskann PROPERTIES
     OUTPUT_NAME zvec_diskann_plugin
-)
+)

tests/core/algorithm/diskann/CMakeLists.txt

@@ -1,4 +1,4 @@
-include(${CMAKE_SOURCE_DIR}/cmake/bazel.cmake)
+include(${PROJECT_ROOT_DIR}/cmake/bazel.cmake)
 
 file(GLOB_RECURSE ALL_TEST_SRCS *_test.cc)
 
@@ -9,6 +9,6 @@ foreach(CC_SRCS ${ALL_TEST_SRCS})
       STRICT
       LIBS zvec_ailego core_framework core_utility core_metric core_quantizer core_knn_cluster core_plugin core_knn_diskann
       SRCS ${CC_SRCS}
-      INCS . ${CMAKE_SOURCE_DIR}/src/core ${CMAKE_SOURCE_DIR}/src/core/algorithm/diskann
+      INCS . ${PROJECT_ROOT_DIR}/src/core ${PROJECT_ROOT_DIR}/src/core/algorithm/diskann
     )
-endforeach()
+endforeach()

thirdparty/FastPFOR/CMakeLists.txt

@@ -1,4 +1,4 @@
-include(${CMAKE_SOURCE_DIR}/cmake/bazel.cmake)
+include(${PROJECT_ROOT_DIR}/cmake/bazel.cmake)
 
 # On ARM platforms, FastPFOR uses SIMDe to emulate SSE intrinsics.
 # Detection covers native ARM builds AND cross-compilation (e.g. iOS/Android).