FindRapidjson.cmake

# Copyright (c) 2011 Milo Yip (miloyip@gmail.com)
# Copyright (c) 2013 Rafal Jeczalik (rjeczalik@gmail.com)
# Distributed under the MIT License (see license.txt file)

# -----------------------------------------------------------------------------------
#
# Finds the rapidjson library
#
# -----------------------------------------------------------------------------------
#
# Variables used by this module, they can change the default behaviour.
# Those variables need to be either set before calling find_package
# or exported as environment variables before running CMake:
#
# RAPIDJSON_INCLUDEDIR - Set custom include path, useful when rapidjson headers are
#                        outside system paths
# RAPIDJSON_USE_SSE2   - Configure rapidjson to take advantage of SSE2 capabilities
# RAPIDJSON_USE_SSE42  - Configure rapidjson to take advantage of SSE4.2 capabilities
#
# -----------------------------------------------------------------------------------
#
# Variables defined by this module:
#
# RAPIDJSON_FOUND        - True if rapidjson was found
# RAPIDJSON_INCLUDE_DIRS - Path to rapidjson include directory
# RAPIDJSON_CXX_FLAGS    - Extra C++ flags required for compilation with rapidjson
#
# -----------------------------------------------------------------------------------
#
# Example usage:
#
#  set(RAPIDJSON_USE_SSE2 ON)
#  set(RAPIDJSON_INCLUDEDIR "/opt/github.com/rjeczalik/rapidjson/include")
#
#  find_package(rapidjson REQUIRED)
#
#  include_directories("${RAPIDJSON_INCLUDE_DIRS}")
#  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${RAPIDJSON_CXX_FLAGS}")
#  add_executable(foo foo.cc)
#
# -----------------------------------------------------------------------------------

foreach(opt RAPIDJSON_INCLUDEDIR RAPIDJSON_USE_SSE2 RAPIDJSON_USE_SSE42)
  if(${opt} AND DEFINED ENV{${opt}} AND NOT ${opt} STREQUAL "$ENV{${opt}}")
    message(WARNING "Conflicting ${opt} values: ignoring environment variable and using CMake cache entry.")
  elseif(DEFINED ENV{${opt}} AND NOT ${opt})
    set(${opt} "$ENV{${opt}}")
  endif()
endforeach()

find_path(
  RAPIDJSON_INCLUDE_DIRS
  NAMES rapidjson/rapidjson.h
  PATHS ${RAPIDJSON_INCLUDEDIR}
  DOC "Include directory for the rapidjson library."
)

mark_as_advanced(RAPIDJSON_INCLUDE_DIRS)

if(RAPIDJSON_INCLUDE_DIRS)
  set(RAPIDJSON_FOUND TRUE)
endif()

mark_as_advanced(RAPIDJSON_FOUND)

if(RAPIDJSON_USE_SSE42)
  set(RAPIDJSON_CXX_FLAGS "-DRAPIDJSON_SSE42")
  if(MSVC)
    set(RAPIDJSON_CXX_FLAGS "${RAPIDJSON_CXX_FLAGS} /arch:SSE4.2")
  else()
    set(RAPIDJSON_CXX_FLAGS "${RAPIDJSON_CXX_FLAGS} -msse4.2")
  endif()
else()
  if(RAPIDJSON_USE_SSE2)
    set(RAPIDJSON_CXX_FLAGS "-DRAPIDJSON_SSE2")
    if(MSVC)
      set(RAPIDJSON_CXX_FLAGS "${RAPIDJSON_CXX_FLAGS} /arch:SSE2")
    else()
      set(RAPIDJSON_CXX_FLAGS "${RAPIDJSON_CXX_FLAGS} -msse2")
    endif()
  endif()
endif()

mark_as_advanced(RAPIDJSON_CXX_FLAGS)

if(RAPIDJSON_FOUND)
  if(NOT rapidjson_FIND_QUIETLY)
    message(STATUS "Found rapidjson header files in ${RAPIDJSON_INCLUDE_DIRS}")
    if(DEFINED RAPIDJSON_CXX_FLAGS)
      message(STATUS "Found rapidjson C++ extra compilation flags: ${RAPIDJSON_CXX_FLAGS}")
    endif()
  endif()
elseif(rapidjson_FIND_REQUIRED)
    message(FATAL_ERROR "Could not find rapidjson")
else()
  message(STATUS "Optional package rapidjson was not found")
endif()