Commit 9b3d60d0 authored by Simon Spannagel's avatar Simon Spannagel
Browse files

Build system: always chose the C++ version ROOT is built against

parent 8c46b2b9

CMakeLists.txt

+36 −31
Original line number Diff line number Diff line
@@ -178,6 +178,34 @@ ENDIF() 
# We need PkgConfig for some dependencies:

FIND_PACKAGE(PkgConfig REQUIRED)





#################################

# Figure out ROOT's C++ version #

#################################



FIND_PACKAGE(ROOT REQUIRED COMPONENTS Geom Core GenVector Hist RIO NO_MODULE)

IF(NOT ROOT_FOUND)

    MESSAGE(FATAL_ERROR "Could not find ROOT, make sure to source the ROOT environment\n"

                        "$ source YOUR_ROOT_DIR/bin/thisroot.sh")

ENDIF()



# Check which C++ version ROOT was built against

IF(ROOT_CXX_FLAGS MATCHES ".*std=c\\+\\+2[0a].*")

    SET(ROOT_CXX_STD 20)

ELSEIF(ROOT_CXX_FLAGS MATCHES ".*std=c\\+\\+1[7z].*")

    SET(ROOT_CXX_STD 17)

ELSEIF(ROOT_CXX_FLAGS MATCHES ".*std=c\\+\\+.*")

    MESSAGE(FATAL_ERROR "ROOT was built with an unsupported C++ version, at least C++17 is required: ${ROOT_CXX_FLAGS}")

ELSE()

    MESSAGE(FATAL_ERROR "Could not deduce ROOT's C++ version from build flags: ${ROOT_CXX_FLAGS}")

ENDIF()



# Check ROOT version

IF(NOT ${ROOT_VERSION} VERSION_GREATER "6.0")

    MESSAGE(FATAL_ERROR "ROOT versions below 6.0 are not supported")

ENDIF()





###################################

# Define build flags for allpix   #

###################################
@@ -226,14 +254,18 @@ IF(CCACHE_FOUND) 
        CACHE PATH "CCache program" FORCE)

ENDIF()



# Require C++17

# Require C++17 or C++20

CHECK_CXX_COMPILER_FLAG(-std=c++17 SUPPORT_STD_CXX17)

CHECK_CXX_COMPILER_FLAG(-std=c++20 SUPPORT_STD_CXX20)

IF(NOT SUPPORT_STD_CXX17)

    MESSAGE(FATAL_ERROR "Compiler does not support required standard C++17")

IF(ROOT_CXX_STD EQUAL 20 AND NOT SUPPORT_STD_CXX20)

    MESSAGE(FATAL_ERROR "Compiler does not support standard required by ROOT: C++20")

ELSEIF(ROOT_CXX_STD EQUAL 17 AND NOT SUPPORT_STD_CXX17)

    MESSAGE(FATAL_ERROR "Compiler does not support standard required by ROOT: C++17")

ENDIF()



SET(CMAKE_CXX_STANDARD 17)

# Build with C++20 or C++17

SET(CMAKE_CXX_STANDARD "${ROOT_CXX_STD}")

MESSAGE(STATUS "Building against C++ version ${CMAKE_CXX_STANDARD}")

SET(CMAKE_CXX_STANDARD_REQUIRED ON)

SET(CMAKE_CXX_EXTENSIONS OFF)
@@ -293,33 +325,6 @@ SET(ALLPIX_BUILD_GEANT4_INTERFACE 
    "OFF"

    CACHE BOOL "Build Geant4 interface library" FORCE)



# ROOT is required for vector and persistency etc

FIND_PACKAGE(ROOT REQUIRED COMPONENTS Geom Core GenVector Hist RIO NO_MODULE)

IF(NOT ROOT_FOUND)

    MESSAGE(FATAL_ERROR "Could not find ROOT, make sure to source the ROOT environment\n"

                        "$ source YOUR_ROOT_DIR/bin/thisroot.sh")

ENDIF()



# Downgrade to C++14 if ROOT is not build with C++17 support

IF(ROOT_CXX_FLAGS MATCHES ".*std=c\\+\\+2[0a].*")

    IF(NOT SUPPORT_STD_CXX20)

        MESSAGE(FATAL_ERROR "ROOT was built with C++20 support but current compiler doesn't support it")

    ENDIF()

ELSEIF(ROOT_CXX_FLAGS MATCHES ".*std=c\\+\\+1[7z].*")

    IF(NOT SUPPORT_STD_CXX17)

        MESSAGE(FATAL_ERROR "ROOT was built with C++17 support but current compiler doesn't support it")

    ENDIF()

ELSEIF(ROOT_CXX_FLAGS MATCHES ".*std=c\\+\\+.*")

    MESSAGE(FATAL_ERROR "ROOT was built with an unsupported C++ version, C++17 is required: ${ROOT_CXX_FLAGS}")

ELSE()

    MESSAGE(FATAL_ERROR "Could not deduce ROOT's C++ version from build flags: ${ROOT_CXX_FLAGS}")

ENDIF()



# Check ROOT version

IF(NOT ${ROOT_VERSION} VERSION_GREATER "6.0")

    MESSAGE(FATAL_ERROR "ROOT versions below 6.0 are not supported")

ENDIF()



# Prepare ROOT Targets if necessary:

ALLPIX_SETUP_ROOT_TARGETS()