CMakeLists.txt

# Copyright (c) Facebook, Inc. and its affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.

cmake_minimum_required(VERSION 3.17 FATAL_ERROR)

project(faiss
  VERSION 1.7.3
  DESCRIPTION "A library for efficient similarity search and clustering of dense vectors."
  HOMEPAGE_URL "https://github.com/facebookresearch/faiss"
  LANGUAGES CXX)
include(GNUInstallDirs)

set(CMAKE_CXX_STANDARD 11)

list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")

# Valid values are "generic", "avx2".
option(FAISS_OPT_LEVEL "" "generic")
option(FAISS_ENABLE_GPU "Enable support for GPU indexes." ON)
option(FAISS_ENABLE_PYTHON "Build Python extension." ON)
option(FAISS_ENABLE_C_API "Build C API." OFF)

if(FAISS_ENABLE_GPU)
  set(CMAKE_CUDA_HOST_COMPILER ${CMAKE_CXX_COMPILER})
  enable_language(CUDA)
endif()

add_subdirectory(faiss)

if(FAISS_ENABLE_GPU)
  add_subdirectory(faiss/gpu)
endif()

if(FAISS_ENABLE_PYTHON)
  add_subdirectory(faiss/python)
endif()

if(FAISS_ENABLE_C_API)
  add_subdirectory(c_api)
endif()

add_subdirectory(demos)
add_subdirectory(benchs)
add_subdirectory(tutorial/cpp)

# CTest must be included in the top level to enable `make test` target.
include(CTest)
if(BUILD_TESTING)
  add_subdirectory(tests)

  if(FAISS_ENABLE_GPU)
    add_subdirectory(faiss/gpu/test)
  endif()
endif()

# include(FetchContent)

# FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz)
# FetchContent_MakeAvailable(json)

# # target_link_libraries(foo PRIVATE nlohmann_json::nlohmann_json)

include(FetchContent)

FetchContent_Declare(
    nlohmann_json
    GIT_REPOSITORY https://github.com/nlohmann/json.git
    GIT_TAG v3.10.4
)

FetchContent_GetProperties(nlohmann_json)
if(NOT nlohmann_json_POPULATED)
    FetchContent_Populate(nlohmann_json)
    add_subdirectory(${nlohmann_json_SOURCE_DIR} ${nlohmann_json_BINARY_DIR})
endif()

target_include_directories(faiss PRIVATE ${nlohmann_json_SOURCE_DIR}/include)

find_package(ZLIB REQUIRED)
target_link_libraries(faiss PUBLIC ${ZLIB_LIBRARIES})