compiler.cmake

# Copyright (C) 2008-2014 LAAS-CNRS, JRL AIST-CNRS.
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program.  If not, see <http://www.gnu.org/licenses/>.

include(CheckCXXCompilerFlag)

macro(_SETUP_PROJECT_WARNINGS)
  # -Wmissing-declarations is disabled for now as older GCC version does not
  # support it but CMake doest not check for the flag acceptance correctly.

  set(GNU_FLAGS
      -pedantic
      -Wno-long-long
      -Wall
      -Wextra
      -Wcast-align
      -Wcast-qual
      -Wformat
      -Wwrite-strings
      -Wconversion)
  if(NOT DEFINED CXX_DISABLE_WERROR)
    list(APPEND GNU_FLAGS -Werror)
  endif(NOT DEFINED CXX_DISABLE_WERROR)

  # For win32 systems, it is impossible to use Wall, especially with boost,
  # which is way too verbose The default levels (W3/W4) are enough The next
  # macro remove warnings on deprecations due to stl.
  set(MSVC_FLAGS
      -D_SCL_SECURE_NO_WARNINGS
      -D_CRT_SECURE_NO_WARNINGS
      -D_CRT_SECURE_NO_DEPRECATE
      # -- The following warnings are removed to highlight the output C4101 The
      # local variable is never used removed since happens frequently in
      # headers.
      /wd4101
      # C4250 'class1' : inherits 'class2::member' via dominance
      /wd4250
      # C4251 class 'type' needs to have dll-interface to be used by clients of
      # class 'type2' ~ in practice, raised by the classes that have non-dll
      # attribute (such as std::vector)
      /wd4251
      # C4275 non - DLL-interface used as base for DLL-interface
      /wd4275
      # C4355 "this" used in base member initializer list
      /wd4355)

  cxx_flags_by_compiler_frontend(
    GNU
    ${GNU_FLAGS}
    MSVC
    ${MSVC_FLAGS}
    OUTPUT
    WARNING_CXX_FLAGS_LIST
    FILTER)
  string(REPLACE ";" " " WARNING_CXX_FLAGS "${WARNING_CXX_FLAGS_LIST}")

  set(CMAKE_CXX_FLAGS "${WARNING_CXX_FLAGS} ${CMAKE_CXX_FLAGS}")

  list(APPEND LOGGING_WATCHED_VARIABLES WARNING_CXX_FLAGS)
endmacro(_SETUP_PROJECT_WARNINGS)

#[=======================================================================[.rst:
.. command:: CXX_FLAGS_BY_COMPILER_FRONTEND(<GCC   [<flags1>...]>
                                            <MSVC  [<flags1>...]>
                                            OUTPUT flags
                                            <FILTER>)

Detect the compiler frontend (the command line interface) and output the
corresponding ``CXX_FLAGS``.

The following arguments allow to specify ``CXX_FLAGS`` for a compiler
frontend:

:param GNU: List of flags for GNU compiler frontend (Gcc, G++)
:param MSVC: List of flags for MSVC compiler frontend (MSVC, ClangCl)

Detected compiler frontend flags are then outputed in the ``OUTPUT``
parameter.

Optional ``FILTER`` parameter filter outputed flags with check_cxx_compiler_flag.

.. warning:: When ``FILTER`` option is activated, definition should by passed with
-D prefix to be valid compiler parameter.

Example
^^^^^^^

.. code-block:: cmake
  CXX_FLAGS_BY_COMPILER_FRONTEND(
    GNU -Wno-conversion -Wno-comment -Wno-self-assign-overloaded
    MSVC  "/bigobj"
    OUTPUT COMPLIE_OPTIONS
    FILTER)
#]=======================================================================]

function(CXX_FLAGS_BY_COMPILER_FRONTEND)
  set(options FILTER)
  set(oneValueArgs OUTPUT)
  set(multiValueArgs GNU MSVC)
  cmake_parse_arguments(ARGS "${options}" "${oneValueArgs}" "${multiValueArgs}"
                        ${ARGN})

  # Before CMake 3.14, the CMAKE_CXX_COMPILER_FRONTEND_VARIANT doesn't exists.
  # Before CMake 3.26, when CMAKE_CXX_COMPILER_ID is set to GNU, MSVC or
  # AppleClang, CMAKE_CXX_COMPILER_FRONTEND_VARIANT doesn't exists either
  if(CMAKE_CXX_COMPILER_FRONTEND_VARIANT)
    if(CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "GNU")
      set(FLAGS ${ARGS_GNU})
    elseif(CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC")
      set(FLAGS ${ARGS_MSVC})
    else()
      message(
        WARNING "Unknown compiler frontend for '${CMAKE_CXX_COMPILER_ID}' "
                "with frontend '${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}'\n"
                "No flags outputed")
    endif()
  else()
    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND CMAKE_CXX_SIMULATE_ID MATCHES
                                                 "MSVC")
      set(FLAGS ${ARGS_MSVC})
    elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
      set(FLAGS ${ARGS_MSVC})
    elseif(CMAKE_CXX_COMPILER_ID MATCHES "Clang|GNU")
      set(FLAGS ${ARGS_GNU})
    else()
      message(
        WARNING "Unknown compiler frontend for '${CMAKE_CXX_COMPILER_ID}' "
                "with simulated ID '${CMAKE_CXX_SIMULATED_ID}'\n"
                "No flags outputed")
    endif()
  endif()

  if(ARGS_FILTER)
    foreach(FLAG ${FLAGS})
      check_cxx_compiler_flag(${FLAG} res_${FLAG})
      if(${res_${FLAG}})
        list(APPEND FILTERED_FLAGS ${FLAG})
      endif()
    endforeach()
  else()
    set(FILTERED_FLAGS ${FLAGS})
  endif()

  set(${ARGS_OUTPUT}
      ${FILTERED_FLAGS}
      PARENT_SCOPE)
endfunction()