CMakeLists.txt

#
# This file is open source software, licensed to you under the terms
# of the Apache License, Version 2.0 (the "License").  See the NOTICE file
# distributed with this work for additional information regarding copyright
# ownership.  You may not use this file except in compliance with the License.
#
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#

#
# Copyright (C) 2018 Scylladb, Ltd.
#

cmake_minimum_required (VERSION 2.8)

project (seastar)

message (WARNING "CMake is not yet supported as the Seastar build system. Please use with caution.")

get_filename_component (SEASTAR_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR} ABSOLUTE)
get_filename_component (SEASTAR_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR} ABSOLUTE)

#
# Prologue.
#
# We define these manually because we want to be explicit about the options that are defined and because CMake defines
# NDEBUG by default, and we don't wish to.

set (CMAKE_CXX_FLAGS_DEBUG "-O0 -g")
set (CMAKE_CXX_FLAGS_RELEASE "-O2")
set (CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g")
set (CMAKE_CXX_FLAGS_MINSIZEREL "-Os")

# Set an option defined in a sub-directory.
# Courtesy of http://edsiper.linuxchile.cl/blog/2016/01/08/cmake-override-subdirectory-options/
macro (set_option option value)
  set (${option} ${value} CACHE INTERNAL "" FORCE)
endmacro ()

#
# Configuration options.
#
option (SEASTAR_ENABLE_TESTS
  "If OFF, used to disable testing altogether." ON)

option (SEASTAR_EXCLUDE_TESTS_BY_DEFAULT
  "If ON, then tests are not built by default when the build tool is invoked"
  ON)

option (SEASTAR_EXCLUDE_APPS_BY_DEFAULT
  "If ON, then applications are not build by default when the build tool is invoked"
  ON)

set (SEASTAR_CXX_DIALECT
  "gnu++17"
  CACHE
  STRING
  "C++ dialect to build with.")

set (SEASTAR_CXX_OPTIMIZATION_FLAGS
  ""
  CACHE
  STRING
  "Extra optimization flags for non-debug builds.")

set (SEASTAR_USER_CXXFLAGS
  ""
  CACHE
  STRING
  "Extra CXXFLAGS, separated by semicolon.")

set (SEASTAR_USER_LDFLAGS
  ""
  CACHE
  STRING
  "Extra LDFLAGS, separated by semicolon.")

option (SEASTAR_ENABLE_HWLOC
  "Enable hwloc support."
  ON)

option (SEASTAR_ENABLE_DPDK
  "Enable DPDK (from bundled sources)."
  OFF)

option (SEASTAR_ENABLE_EXCEPTION_SCALABILITY_WORKAROUND
  "Override the dl_iterate_phdr symbol to workaround C++ exception scalability issues."
  OFF)

set (SEASTAR_ALLOCATOR_PAGE_SIZE
  ""
  CACHE
  STRING
  "Override the allocator page size in bytes.")

option (SEASTAR_ENABLE_ALLOC_FAILURE_INJECTOR
  "Enable allocation failure injection."
  OFF)

option (SEASTAR_ENABLE_GCC6_CONCEPTS
  "Enable experimental support for C++ concepts as implemented in GCC 6."
  OFF)

option (SEASTAR_LINK_STATIC_BOOST
  "Link with the Boost library statically."
  OFF)

option (SEASTAR_LINK_STATIC_YAML_CPP
  "Link with the yaml-cpp library statically."
  OFF)

option (SEASTAR_EXECUTE_ONLY_FAST_TESTS
  "Execute fast unit tests only, where applicable."
  OFF)

set (SEASTAR_JENKINS
  ""
  CACHE
  STRING
  "Configure the build and tests for execution within a Jenkins context, with the given identifier.")

#
# Link pools (only supported for the Ninja generator).
#

if (${CMAKE_GENERATOR} STREQUAL "Ninja")
  exec_program ("${CMAKE_CURRENT_SOURCE_DIR}/cmake-tools/query_link_pool_depth.py"
    OUTPUT_VARIABLE link_pool_depth
    RETURN_VALUE query_pool_depth_code)

  if (NOT ("${query_pool_depth_code}" STREQUAL 0))
    MESSAGE (FATAL_ERROR "tools/query_link_pool_depth.py had a non-zero exit code.")
  endif ()

  set_property (GLOBAL PROPERTY
    JOB_POOLS
    seastar_link_pool=${link_pool_depth})

  set_property (GLOBAL PROPERTY
    CMAKE_JOB_POOL_LINK seastar_link_pool)
endif ()

#
# External projects.
#

set_option (CARES_STATIC YES)
set_option (CARES_SHARED NO)
set_option (CARES_INSTALL NO)
set_option (CARES_STATIC_PIC YES)
add_subdirectory (c-ares)

add_subdirectory (fmt)

#
# System dependencies.
#

set (CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH}" "${CMAKE_CURRENT_SOURCE_DIR}/cmake")

##
## Unconditional dependencies.
##

if (${SEASTAR_LINK_STATIC_BOOST})
  set (Boost_USE_STATIC_LIBS ON)
endif ()

if (NOT TARGET Boost)
  find_package (Boost COMPONENTS program_options filesystem unit_test_framework thread REQUIRED)
endif()

if (${Boost_VERSION} VERSION_LESS "1.58")
  message(error "Seastar requires Boost >= 1.58")
endif ()

find_package (GnuTLS REQUIRED)

find_package (Protobuf REQUIRED)

find_package (Cryptopp REQUIRED)

find_package (Lz4 REQUIRED)

find_package (Yaml-cpp REQUIRED)

find_library (RT_LIBRARY rt DOC "The Posix Realtime extension library.")

find_program (Ragel_EXECUTABLE NAMES ragel DOC "Path to the ragel executable.")

##
## Conditional dependencies.
##

if (${SEASTAR_ENABLE_HWLOC})
  find_package (HWLoc REQUIRED)

  find_package (LibXml2 REQUIRED)

  find_package (ZLIB REQUIRED)

  find_library (NUMA_LIBRARY numa DOC "The NUMA support library.")

  find_library (PCIAccess_LIBRARY pciaccess DOC "The pciaccess library.")
endif ()

#
# Code generation.
#

add_subdirectory (proto)

function (seastar_ragel_generate file output_var)
  set (abs_file "${CMAKE_CURRENT_SOURCE_DIR}/${file}")

  get_filename_component (base_name ${file} NAME_WE)
  set (output_name "${base_name}.hh")

  add_custom_command (
    OUTPUT "${output_name}"
    MAIN_DEPENDENCY ${abs_file}
    COMMAND ${Ragel_EXECUTABLE} -G2 -o ${output_name} ${abs_file}
    # sed away a bug in ragel 7 that emits some extraneous _nfa* variables.
    COMMAND sed -i -e '1h\;2,$$H\;$$!d\;g' -re 's/static const char _nfa[^\;]*\;//g' ${output_name})

  set ("${output_var}" "${CMAKE_CURRENT_BINARY_DIR}/${output_name}" PARENT_SCOPE)
endfunction ()

function (seastar_swagger_generate file output_var)
  set (abs_file "${CMAKE_CURRENT_SOURCE_DIR}/${file}")
  set (output_name "${file}.hh")
  set (output_path "${CMAKE_CURRENT_BINARY_DIR}/${output_name}")

  add_custom_command (
    OUTPUT ${output_path}
    MAIN_DEPENDENCY ${abs_file}
    COMMAND "${SEASTAR_SOURCE_DIR}/json/json2code.py" -f ${abs_file} -o ${output_path})

  set ("${output_var}" ${output_path} PARENT_SCOPE)
endfunction ()

add_subdirectory (http)

#
# Sources.
#

set (core_files
  core/abort_source.hh
  core/alien.hh core/alien.cc
  core/align.hh
  core/aligned_buffer.hh
  core/app-template.hh core/app-template.cc
  core/apply.hh
  core/array_map.hh
  core/bitops.hh
  core/bitset-iter.hh
  core/byteorder.hh
  core/cacheline.hh
  core/checked_ptr.hh
  core/chunked_fifo.hh
  core/circular_buffer.hh
  core/circular_buffer_fixed_capacity.hh
  core/condition-variable.hh
  core/deleter.hh
  core/distributed.hh
  core/do_with.hh
  core/dpdk_rte.hh core/dpdk_rte.cc
  core/enum.hh
  core/exception_hacks.hh core/exception_hacks.cc
  core/execution_stage.hh
  core/expiring_fifo.hh
  core/fair_queue.hh
  core/file-impl.hh
  core/file.hh
  core/fsqual.hh core/fsqual.cc
  core/fstream.hh core/fstream.cc
  core/function_traits.hh
  core/future-util.hh core/future-util.cc
  core/future.hh
  core/gate.hh
  core/iostream-impl.hh
  core/iostream.hh
  core/linux-aio.hh core/linux-aio.cc
  core/lowres_clock.hh
  core/manual_clock.hh
  core/memory.hh core/memory.cc
  core/metrics.hh core/metrics.cc
  core/metrics_api.hh
  core/metrics_registration.hh
  core/metrics_types.hh
  core/pipe.hh
  core/posix.hh core/posix.cc
  core/preempt.hh
  core/prefetch.hh
  core/print.hh
  core/prometheus.hh core/prometheus.cc
  core/queue.hh
  core/ragel.hh
  core/reactor.hh core/reactor.cc
  core/report_exception.hh
  core/resource.hh core/resource.cc
  core/rwlock.hh
  core/scattered_message.hh
  core/scheduling.hh
  core/scollectd-impl.hh
  core/scollectd.hh core/scollectd.cc
  core/scollectd_api.hh
  core/seastar.hh
  core/semaphore.hh
  core/sharded.hh
  core/shared_future.hh
  core/shared_mutex.hh
  core/shared_ptr.hh
  core/shared_ptr_debug_helper.hh
  core/shared_ptr_incomplete.hh
  core/simple-stream.hh
  core/slab.hh
  core/sleep.hh
  core/sstring.hh
  core/stall_sampler.hh
  core/stream.hh
  core/systemwide_memory_barrier.hh core/systemwide_memory_barrier.cc
  core/task.hh
  core/temporary_buffer.hh
  core/thread.hh core/thread.cc
  core/thread_impl.hh
  core/timer-set.hh
  core/timer.hh
  core/transfer.hh
  core/unaligned.hh
  core/units.hh
  core/vector-data-sink.hh
  core/vla.hh
  core/weak_ptr.hh)

set (http_files
  http/api_docs.hh http/api_docs.cc
  http/common.hh http/common.cc
  http/exception.hh
  http/file_handler.hh http/file_handler.cc
  http/function_handlers.hh
  http/handlers.hh
  http/httpd.hh http/httpd.cc
  http/json_path.hh http/json_path.cc
  http/matcher.hh http/matcher.cc
  http/matchrules.hh
  http/mime_types.hh http/mime_types.cc
  http/reply.hh http/reply.cc
  http/request.hh
  http/routes.hh http/routes.cc
  http/transformers.hh http/transformers.cc)

set (json_files
  json/formatter.hh json/formatter.cc
  json/json_elements.hh json/json_elements.cc)

set (net_files
  net/api.hh
  net/arp.hh net/arp.cc
  net/byteorder.hh
  net/config.hh net/config.cc
  net/const.hh
  net/dhcp.hh net/dhcp.cc
  net/dns.hh net/dns.cc
  net/dpdk.hh net/dpdk.cc
  net/ethernet.hh net/ethernet.cc
  net/inet_address.hh net/inet_address.cc
  net/ip.hh net/ip.cc
  net/ip_checksum.hh net/ip_checksum.cc
  net/native-stack-impl.hh
  net/native-stack.hh net/native-stack.cc
  net/net.hh net/net.cc
  net/packet-data-source.hh
  net/packet-util.hh
  net/packet.hh net/packet.cc
  net/posix-stack.hh net/posix-stack.cc
  net/proxy.hh net/proxy.cc
  net/socket_defs.hh
  net/stack.hh net/stack.cc
  net/tcp-stack.hh
  net/tcp.hh net/tcp.cc
  net/tls.hh net/tls.cc
  net/toeplitz.hh
  net/udp.hh net/udp.cc
  net/virtio-interface.hh
  net/virtio.hh net/virtio.cc)

set (rpc_files
  rpc/lz4_compressor.hh rpc/lz4_compressor.cc
  rpc/multi_algo_compressor_factory.hh
  rpc/rpc.hh rpc/rpc.cc
  rpc/rpc_impl.hh
  rpc/rpc_types.hh)

set (util_files
  util/alloc_failure_injector.hh util/alloc_failure_injector.cc
  util/backtrace.hh util/backtrace.cc
  util/bool_class.hh
  util/conversions.hh util/conversions.cc
  util/defer.hh
  util/eclipse.hh
  util/function_input_iterator.hh
  util/gcc6-concepts.hh
  util/indirect.hh
  util/is_smart_ptr.hh
  util/lazy.hh
  util/log.hh util/log.cc
  util/log-cli.hh
  util/noncopyable_function.hh
  util/optimized_optional.hh
  util/print_safe.hh
  util/program-options.hh util/program-options.cc
  util/reference_wrapper.hh
  util/spinlock.hh
  util/transform_iterator.hh
  util/tuple_utils.hh
  util/variant_utils.hh)

add_library (seastar
  ${core_files}
  ${http_files}
  ${json_files}
  ${net_files}
  ${rpc_files}
  ${util_files}
  $<TARGET_OBJECTS:seastar-protobuf>)

add_dependencies (seastar
  seastar-http-response-parser
  seastar-http-request-parser)

add_library (Seastar::seastar ALIAS seastar)

#
# DPDK.
#

if (${SEASTAR_ENABLE_DPDK})
  set (dpdk_source_dir "${CMAKE_CURRENT_SOURCE_DIR}/dpdk")
  set (dpdk_binary_dir "${CMAKE_CURRENT_BINARY_DIR}/dpdk")

  #
  # Oh, CMake...
  #

  set (arch "")
  foreach (flag ${SEASTAR_USER_CXXFLAGS})
    if (${flag} MATCHES "-march=(.+)")
      set (arch ${CMAKE_MATCH_1})
    endif ()
  endforeach ()

  if ("${arch}" STREQUAL "nehalem")
    set (dpdk_machine "nhm")
  elseif ("${arch}" STREQUAL "westmere")
    set (dpdk_machine "wsm")
  elseif ("${arch}" STREQUAL "sandybridge")
    set (dpdk_machine "snb")
  elseif ("${arch}" STREQUAL "ivybridge")
    set (dpdk_machine "ivb")
  else ()
    set (dpdk_machine "native")
  endif ()

  if (EXISTS "${dpdk_binary_dir}/.config")
    file (REMOVE "${dpdk_binary_dir}/.config")
  endif ()

  exec_program (make
    ARGS -C ${dpdk_source_dir} RTE_OUTPUT=${dpdk_binary_dir} config "T=x86_64-${dpdk_machine}-linuxapp-gcc")

  exec_program ("${CMAKE_CURRENT_SOURCE_DIR}/cmake-tools/dpdk_adjust_variables.py"
    ARGS "${dpdk_binary_dir}/.config" ${dpdk_machine})

  exec_program ("${CMAKE_CURRENT_SOURCE_DIR}/cmake-tools/dpdk_query_cflags.py"
    ARGS ${dpdk_binary_dir} ${dpdk_machine}
    OUTPUT_VARIABLE dpdk_cflags)

  add_custom_target (seastar-dpdk
    COMMAND make -C ${dpdk_binary_dir} CC=\"${CMAKE_C_COMPILER} -Wno-implicit-fallthrough -Wno-format-truncation -Wno-bool-operation -Wno-maybe-uninitialized\")

  add_dependencies (seastar seastar-dpdk)

  target_include_directories (seastar SYSTEM PUBLIC "${dpdk_binary_dir}/include")
  target_compile_options (seastar PUBLIC "${dpdk_cflags}")
endif ()

#
# Compilation flags and definitions.
#

target_compile_options (seastar
  PRIVATE
    -Wall
    -Werror

  PUBLIC
    "-std=${SEASTAR_CXX_DIALECT}"
    -Wno-error=deprecated-declarations
    -fvisibility=hidden
    -U_FORTIFY_SOURCE)

if ("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
  target_compile_options (seastar PUBLIC
    -fsanitize=address
    -fsanitize=leak
    -fsanitize=undefined)

  target_compile_definitions (seastar PUBLIC
    SEASTAR_DEBUG
    SEASTAR_DEBUG_SHARED_PTR
    SEASTAR_DEFAULT_ALLOCATOR
    SEASTAR_THREAD_STACK_GUARDS
    SEASTAR_ASAN_ENABLED
    SEASTAR_SHUFFLE_TASK_QUEUE)
else ()
  target_compile_options (seastar PUBLIC "${SEASTAR_CXX_OPTIMIZATION_FLAGS}")
endif ()

if (${SEASTAR_ENABLE_GCC6_CONCEPTS})
  target_compile_options (seastar PUBLIC -fconcepts)
  target_compile_definitions (seastar PUBLIC SEASTAR_HAVE_GCC6_CONCEPTS)
endif ()

if (NOT ${SEASTAR_ENABLE_EXCEPTION_SCALABILITY_WORKAROUND})
  target_compile_definitions (seastar PUBLIC
    SEASTAR_NO_EXCEPTION_HACK)
endif ()

if (${SEASTAR_ENABLE_HWLOC})
  target_compile_definitions (seastar PUBLIC
    SEASTAR_HAVE_HWLOC SEASTAR_HAVE_NUMA)
endif ()

if (${SEASTAR_ENABLE_DPDK})
  target_compile_options (seastar PUBLIC
    -Wno-error=literal-suffix
    -Wno-literal-suffix
    -Wno-invalid-offsetof)

  target_compile_definitions (seastar PUBLIC
    SEASTAR_HAVE_DPDK)
endif ()

if (${SEASTAR_ALLOCATOR_PAGE_SIZE})
  target_compile_definitions (seastar PUBLIC
    SEASTAR_OVERRIDE_ALLOCATOR_PAGE_SIZE=${SEASTAR_ALLOCATOR_PAGE_SIZE})
endif ()

if (${SEASTAR_ENABLE_ALLOC_FAILURE_INJECTOR})
  target_compile_definitions (seastar PUBLIC
    SEASTAR_ENABLE_ALLOC_FAILURE_INJECTION)
endif ()

##
## Code tests.
##

###
### have_lz4_compress_default
###

set (CMAKE_REQUIRED_INCLUDES ${Lz4_INCLUDE_DIRS})
set (CMAKE_REQUIRED_LIBRARIES ${Lz4_LIBRARIES})
check_symbol_exists (LZ4_compress_default lz4.h have_lz4_compress_default)

if (${have_lz4_compress_default})
  target_compile_definitions (seastar PUBLIC SEASTAR_HAVE_LZ4_COMPRESS_DEFAULT)
endif ()

###
### have_asan_fiber_support
###

try_compile (have_asan_fiber_support
  ${CMAKE_CURRENT_BINARY_DIR}
  ${CMAKE_CURRENT_SOURCE_DIR}/cmake-tests/asan_fiber.cc
  LINK_LIBRARIES -fsanitize=address)

if (${have_asan_fiber_support})
  target_compile_definitions (seastar PUBLIC SEASTAR_HAVE_ASAN_FIBER_SUPPORT)
endif ()

###
### have_sanitize_vptr_flag
###

# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67258
check_cxx_compiler_flag (-fsanitize=vptr have_sanitize_vptr_flag)

set (ENV{UBSAN_OPTIONS} "exitcode=1")
try_run (sanitize_vptr_run sanitize_vptr_compile
  ${CMAKE_CURRENT_BINARY_DIR}
  ${CMAKE_CURRENT_SOURCE_DIR}/cmake-tests/sanitize_vptr.cc
  CMAKE_FLAGS -DCMAKE_CXX_FLAGS="-fsanitize=undefined -fno-sanitize-recover")

# TODO: -fsanitize=vptr is broken even when the test passes.
if ((NOT "${have_sanitize_vptr_flag}") OR "${sanitize_vptr_run}" AND FALSE)
else ()
  if ("${CMAKE_BUILD_TYPE}" STREQUAL Debug)
    message (STATUS "-fsanitize=vptr is broken; disabling. Some debug-mode tests are bypassed.")
    target_compile_options (seastar PUBLIC -fno-sanitize=vptr)
  endif ()
endif ()

###
### visibility_flags_compile
###

# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80947
try_compile (visiblity_flags_compile
  ${CMAKE_CURRENT_BINARY_DIR}
  ${CMAKE_CURRENT_SOURCE_DIR}/cmake-tests/visibility_flags.cc
  CMAKE_FLAGS -DCMAKE_CXX_FLAGS="-fvisibility=hidden -std=gnu++1y -Werror=attributes")

if (NOT "${visibility_flags_compile}")
  message (STATUS "Disabling -Wattributes due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80947")
  target_compile_options (seastar PUBLIC -Wno-attributes)
endif ()

###
### have_membarrier
###

try_compile (have_membarrier
  ${CMAKE_CURRENT_BINARY_DIR}
  ${CMAKE_CURRENT_SOURCE_DIR}/cmake-tests/have_membarrier.cc)

if (${have_membarrier})
  target_compile_definitions (seastar PUBLIC SEASTAR_HAS_MEMBARRIER)
endif ()

##
## Warnings.
##

function (seastar_add_warning_if_supported warning)
  # GCC ignores the `-Wno` prefix even when the warning is not recognized, so strip it.
  string (REGEX REPLACE "^-Wno-" "-W" adjusted ${warning})
  string (REGEX REPLACE "^-W" "warning_" human_name_prefix ${adjusted})
  set (result "${human_name_prefix}_supported")
  check_cxx_compiler_flag (${adjusted} ${result})

  if ("${${result}}")
    target_compile_options (seastar PUBLIC ${warning})
  endif ()
endfunction ()

# Clang-only.
seastar_add_warning_if_supported (-Wno-mismatched-tags)

# Clang-only: moving a temporary object prevents copy elision.
seastar_add_warning_if_supported (-Wno-pessimizing-move)

# Clang-only: redundant move in return statement.
seastar_add_warning_if_supported (-Wno-redundant-move)

# Clang-only: 'x' overrides a member function but is not marked 'override'.
seastar_add_warning_if_supported (-Wno-inconsistent-missing-override)

# Clang-only: private field 'x' is not used.
seastar_add_warning_if_supported (-Wno-unused-private-field)

# Clang-only: unknown attribute 'x' ignored (x in this case is gnu::externally_visible).
seastar_add_warning_if_supported (-Wno-unknown-attributes)

# Clang-only: 'x' function 'y' declared in header file should be declared 'z'.
seastar_add_warning_if_supported (-Wno-unneeded-internal-declaration)

# Clang-only: inline function 'x' is not defined.
seastar_add_warning_if_supported (-Wno-undefined-inline)

# Clang-only: 'x' hides overloaded virtual functions.
seastar_add_warning_if_supported (-Wno-overloaded-virtual)

seastar_add_warning_if_supported (-Wno-maybe-uninitialized)

# GCC: Overzealous: false positives.
seastar_add_warning_if_supported (-Wno-stringop-overflow)

seastar_add_warning_if_supported (-Wno-error=cpp)

##
## Extra flags at the end.
##

target_compile_options (seastar PUBLIC "${SEASTAR_USER_CXXFLAGS}")

#
# Configuration.
#

target_include_directories (seastar SYSTEM
  PUBLIC
    ${GNUTLS_INCLUDE_DIR})

target_include_directories (seastar PUBLIC
  ${CMAKE_CURRENT_SOURCE_DIR}
  ${CMAKE_CURRENT_BINARY_DIR})

if (${SEASTAR_NABLE_HWLOC})
  target_include_directories (seastar SYSTEM
    PUBLIC
      ${LIBXML2_INCLUDE_DIRS})
endif ()

target_link_libraries (seastar PUBLIC
  -Wl,--no-as-needed
  -fvisibility=hidden)

target_link_libraries (seastar PUBLIC
  debug -fsanitize=address
  debug -fsanitize=leak
  debug -fsanitize=undefined
  stdc++fs
  -ldl
  -lgcc_s
  ${CMAKE_THREAD_LIBS_INIT}
  ${GNUTLS_LIBRARIES}
  ${PROTOBUF_LIBRARIES}
  ${RT_LIBRARY}
  Boost::boost # Headers only.
  Cryptopp::cryptopp
  Lz4::lz4
  fmt::fmt
  c-ares::cares)

function (seastar_maybe_link_statically static_flag)
  string (REPLACE ";" "," joined_targets "${ARGN}")

  if (${static_flag})
    target_link_libraries (seastar PUBLIC "-Wl,-Bstatic" "${joined_targets}" "-Wl,-Bdynamic")
  else ()
    target_link_libraries (seastar PUBLIC "${ARGN}")
  endif ()
endfunction ()

seastar_maybe_link_statically (${SEASTAR_LINK_STATIC_BOOST}
  Boost::program_options
  Boost::filesystem
  Boost::thread)

seastar_maybe_link_statically (${SEASTAR_LINK_STATIC_YAML_CPP}
  Yaml-cpp::yaml-cpp)

if (${SEASTAR_ENABLE_HWLOC})
  target_link_libraries (seastar PUBLIC
    ${NUMA_LIBRARY}
    ${PCIAccess_LIBRARY}
    ${LIBXML2_LIBRARIES}
    HWLoc::hwloc
    ZLIB::ZLIB)
endif ()

if (${SEASTAR_ENABLE_DPDK})
  set (dpdk_libraries
    -lrte_pmd_vmxnet3_uio
    -lrte_pmd_i40e
    -lrte_pmd_ixgbe
    -lrte_pmd_e1000
    -lrte_pmd_ring
    -lrte_pmd_bnxt
    -lrte_pmd_cxgbe
    -lrte_pmd_ena
    -lrte_pmd_enic
    -lrte_pmd_fm10k
    -lrte_pmd_nfp
    -lrte_pmd_qede
    -lrte_pmd_sfc_efx
    -lrte_hash
    -lrte_kvargs
    -lrte_mbuf
    -lrte_ethdev
    -lrte_eal
    -lrte_mempool
    -lrte_ring
    -lrte_cmdline
    -lrte_cfgfile)

  string (REPLACE ";" "," joined_dpdk_libraries "${dpdk_libraries}")

  target_link_libraries (seastar PUBLIC
    -L"${dpdk_binary_dir}/lib"
    -Wl,--whole-archive,${joined_dpdk_libraries},--no-whole-archive)
endif ()

target_link_libraries (seastar PUBLIC "${SEASTAR_USER_LDFLAGS}")

#
# Applications.
#

if (${SEASTAR_EXCLUDE_APPS_BY_DEFAULT})
  set (exclude_apps EXCLUDE_FROM_ALL)
else ()
  set (exclude_apps "")
endif ()

add_subdirectory (apps ${exclude_apps})

#
# Tests.
#

enable_testing ()

if (${SEASTAR_EXCLUDE_TESTS_BY_DEFAULT})
  set (exclude_tests EXCLUDE_FROM_ALL)
else ()
  set (exclude_tests "")
endif ()

if(${SEASTAR_ENABLE_TESTS})
  add_subdirectory (tests ${exclude_tests})
endif()
#
# Documentation.
#

add_custom_target (tutorial-html
  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
  COMMAND
    pandoc
    --self-contained
    --smart
    --toc
    -c doc/template.css
    -V documentclas=report
    --chapters
    --number-sections
    -f markdown_github+pandoc_title_block
    --highlight-style tango
    doc/tutorial.md
    -o doc/tutorial.html)

add_custom_target (tutorial-html-split
  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/doc"
  COMMAND mkdir -p split && ./htmlsplit.py
  DEPENDS tutorial-html)

add_custom_target (tutorial-pdf
  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
  COMMAND
    pandoc
    -f markdown_github+pandoc_title_block
    --highlight-style tango
    --template=doc/template.tex
    doc/tutorial.md
    -o doc/tutorial.pdf)

#
# Source code navigation tools.
#

add_custom_target (cscope
  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
  COMMAND sh -c find -name '*.[chS]' -o -name '*.cc' -o -name '*.hh' | cscope -bq -i-)

#
# Generate pkg-config specification.
#
# This is quite ugly, since we need to extract information from imported targets
# (like `Boost::program_options`) and resolve generator expessions ($<...>).
# CMake doesn't make it easy to do either.

set (imported_target_regex "[a-zA-Z0-9_\\-]+::[a-zA-ZA0-9_\\-]+")

set (pc_cflags "")
set (pc_libs "")

##
## Query an imported target for all its non-linking compiler options.
##
function (seastar_expand_imported_target_cflags target output)
  get_target_property (definitions ${target} INTERFACE_COMPILE_DEFINITIONS)
  get_target_property (options ${target} INTERFACE_COMPILE_OPTIONS)
  get_target_property (include_dirs ${target} INTERFACE_INCLUDE_DIRECTORIES)

  set (cflags "")
  if (definitions)
    # All definitions need to be prefixed with -D.
    string (REGEX REPLACE "([^;]+)" -D\\1 definitions_args "${definitions}")
    list (APPEND cflags "${definitions_args}")
  endif ()
  if (options)
    list (APPEND cflags "${options}")
  endif ()
  if (include_dirs)
    list (REMOVE_DUPLICATES include_dirs)

    ##
    ## All directories need to be prefixed with -I. We only care about
    ## BUILD_INTERFACE directories, so we have to manually remove the
    ## INSTALL_INTERFACE ones.
    ##

    string (REGEX REPLACE "([^;]+)" -I\\1 include_dirs_args "${include_dirs}")
    string (REGEX REPLACE "-I\\$<INSTALL_INTERFACE:.+>" "" include_dirs_args_no_empty "${include_dirs_args}")
    list (APPEND cflags "${include_dirs_args_no_empty}")
  endif ()

  set ("${output}" "${cflags}" PARENT_SCOPE)
endfunction ()

function (seastar_expand_imported_target_libs target output)
  get_target_property (libs ${target} INTERFACE_LINK_LIBRARIES)
  set ("${output}" "${libs}" PARENT_SCOPE)
endfunction ()

##
## Start with the CMAKE_CXX cflags.
##

string (TOUPPER "${CMAKE_BUILD_TYPE}" build_type_uppercase)
string (REGEX REPLACE "[ ]+" ";" global_cflags "${CMAKE_CXX_FLAGS_${build_type_uppercase}}")
list (APPEND pc_cflags "${global_cflags}")

seastar_expand_imported_target_cflags (Seastar::seastar seastar_cflags)
list (APPEND pc_cflags "${seastar_cflags}")

##
## We expand the seastar library flags and process each one, looking for imported targets.
##

seastar_expand_imported_target_libs (Seastar::seastar seastar_libs_raw)
foreach (lib ${seastar_libs_raw})
  if (${lib} MATCHES ${imported_target_regex})
    ##
    ## For an imported target, expand its CFLAGS.
    ##

    seastar_expand_imported_target_cflags (${lib} lib_cflags)
    list (APPEND pc_cflags "${lib_cflags}")

    ##
    ## For non-header-only libraries, add the imported target's actual library file.
    ##

    get_target_property (lib_type ${lib} TYPE)
    if (NOT ("${lib_type}" STREQUAL INTERFACE_LIBRARY))
      set (lib_location $<TARGET_FILE:${lib}>)
      list (APPEND pc_libs "${lib_location}")
    endif ()
  else ()
    list (APPEND pc_libs "${lib}")
  endif ()
endforeach ()

list (REMOVE_DUPLICATES pc_cflags)

set (pc_file "${CMAKE_CURRENT_BINARY_DIR}/seastar.pc")

# At this point, both pc_libs and pc_cflags can contain generator expressions
# ($<...>). CMake gives us no way to evaluate these in code. They are evaluated
# by CMake internally at the build phase (but not the configure phase). Creating
# a target and echoing the strings forces their evaluation at the right time.
# This would not be possible with CONFIGURE_FILE.
#
# Note that seastar needs to be listed prior to other static libraries to
# prevent symbols from being omitted from them.
add_custom_target (pkg-config ALL
  COMMAND echo "Name: Seastar" > ${pc_file}
  COMMAND echo "URL: http://seastar-project.org/" >> ${pc_file}
  COMMAND echo "Description: Advanced C++ framework for high-performance server applications on modern hardware." >> ${pc_file}
  COMMAND echo "Version: 1.0" >> ${pc_file}
  COMMAND echo "Libs:" '-Wl,--whole-archive,$<TARGET_FILE:Seastar::seastar>,--no-whole-archive' '${pc_libs}' >> ${pc_file}
  COMMAND echo "Cflags:" '${pc_cflags}' >> ${pc_file})