# number of parallel jobs for CTest
set(N 10)

###############################################################################
# Needed tools.
###############################################################################

include(FindPython3)
find_package(Python3 COMPONENTS Interpreter)

find_program(ASTYLE_TOOL NAMES astyle)
execute_process(COMMAND ${ASTYLE_TOOL} --version OUTPUT_VARIABLE ASTYLE_TOOL_VERSION ERROR_VARIABLE ASTYLE_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" ASTYLE_TOOL_VERSION "${ASTYLE_TOOL_VERSION}")
message(STATUS "🔖 Artistic Style ${ASTYLE_TOOL_VERSION} (${ASTYLE_TOOL})")

find_program(CLANG_TOOL NAMES clang++-HEAD clang++ clang++-20 clang++-19 clang++-18 clang++-17 clang++-16 clang++-15 clang++-14 clang++-13 clang++-12 clang++-11 clang++)
execute_process(COMMAND ${CLANG_TOOL} --version OUTPUT_VARIABLE CLANG_TOOL_VERSION ERROR_VARIABLE CLANG_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" CLANG_TOOL_VERSION "${CLANG_TOOL_VERSION}")
message(STATUS "🔖 Clang ${CLANG_TOOL_VERSION} (${CLANG_TOOL})")

find_program(CLANG_TIDY_TOOL NAMES clang-tidy-17 clang-tidy-16 clang-tidy-15 clang-tidy-14 clang-tidy-13 clang-tidy-12 clang-tidy-11 clang-tidy)
execute_process(COMMAND ${CLANG_TIDY_TOOL} --version OUTPUT_VARIABLE CLANG_TIDY_TOOL_VERSION ERROR_VARIABLE CLANG_TIDY_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" CLANG_TIDY_TOOL_VERSION "${CLANG_TIDY_TOOL_VERSION}")
message(STATUS "🔖 Clang-Tidy ${CLANG_TIDY_TOOL_VERSION} (${CLANG_TIDY_TOOL})")

message(STATUS "🔖 CMake ${CMAKE_VERSION} (${CMAKE_COMMAND})")

find_program(CPPCHECK_TOOL NAMES cppcheck)
execute_process(COMMAND ${CPPCHECK_TOOL} --version OUTPUT_VARIABLE CPPCHECK_TOOL_VERSION ERROR_VARIABLE CPPCHECK_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" CPPCHECK_TOOL_VERSION "${CPPCHECK_TOOL_VERSION}")
message(STATUS "🔖 Cppcheck ${CPPCHECK_TOOL_VERSION} (${CPPCHECK_TOOL})")

find_program(GCC_TOOL NAMES g++-latest g++-HEAD g++-13 g++-12 g++-11 g++-10)
execute_process(COMMAND ${GCC_TOOL} --version OUTPUT_VARIABLE GCC_TOOL_VERSION ERROR_VARIABLE GCC_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" GCC_TOOL_VERSION "${GCC_TOOL_VERSION}")
message(STATUS "🔖 GCC ${GCC_TOOL_VERSION} (${GCC_TOOL})")

find_program(GCOV_TOOL NAMES gcov-HEAD gcov-11 gcov-10 gcov)
execute_process(COMMAND ${GCOV_TOOL} --version OUTPUT_VARIABLE GCOV_TOOL_VERSION ERROR_VARIABLE GCOV_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" GCOV_TOOL_VERSION "${GCOV_TOOL_VERSION}")
message(STATUS "🔖 GCOV ${GCOV_TOOL_VERSION} (${GCOV_TOOL})")

find_program(GIT_TOOL NAMES git)
execute_process(COMMAND ${GIT_TOOL} --version OUTPUT_VARIABLE GIT_TOOL_VERSION ERROR_VARIABLE GIT_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" GIT_TOOL_VERSION "${GIT_TOOL_VERSION}")
message(STATUS "🔖 Git ${GIT_TOOL_VERSION} (${GIT_TOOL})")

find_program(IWYU_TOOL NAMES include-what-you-use iwyu)
execute_process(COMMAND ${IWYU_TOOL} --version OUTPUT_VARIABLE IWYU_TOOL_VERSION ERROR_VARIABLE IWYU_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" IWYU_TOOL_VERSION "${IWYU_TOOL_VERSION}")
message(STATUS "🔖 include-what-you-use ${IWYU_TOOL_VERSION} (${IWYU_TOOL})")

find_program(INFER_TOOL NAMES infer)
execute_process(COMMAND ${INFER_TOOL} --version OUTPUT_VARIABLE INFER_TOOL_VERSION ERROR_VARIABLE INFER_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" INFER_TOOL_VERSION "${INFER_TOOL_VERSION}")
message(STATUS "🔖 Infer ${INFER_TOOL_VERSION} (${INFER_TOOL})")

find_program(LCOV_TOOL NAMES lcov)
execute_process(COMMAND ${LCOV_TOOL} --version OUTPUT_VARIABLE LCOV_TOOL_VERSION ERROR_VARIABLE LCOV_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" LCOV_TOOL_VERSION "${LCOV_TOOL_VERSION}")
message(STATUS "🔖 LCOV ${LCOV_TOOL_VERSION} (${LCOV_TOOL})")

find_program(NINJA_TOOL NAMES ninja)
execute_process(COMMAND ${NINJA_TOOL} --version OUTPUT_VARIABLE NINJA_TOOL_VERSION ERROR_VARIABLE NINJA_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" NINJA_TOOL_VERSION "${NINJA_TOOL_VERSION}")
message(STATUS "🔖 Ninja ${NINJA_TOOL_VERSION} (${NINJA_TOOL})")

find_program(OCLINT_TOOL NAMES oclint-json-compilation-database)
find_program(OCLINT_VERSION_TOOL NAMES oclint)
execute_process(COMMAND ${OCLINT_VERSION_TOOL} --version OUTPUT_VARIABLE OCLINT_TOOL_VERSION ERROR_VARIABLE OCLINT_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" OCLINT_TOOL_VERSION "${OCLINT_TOOL_VERSION}")
message(STATUS "🔖 OCLint ${OCLINT_TOOL_VERSION} (${OCLINT_TOOL})")

find_program(VALGRIND_TOOL NAMES valgrind)
execute_process(COMMAND ${VALGRIND_TOOL} --version OUTPUT_VARIABLE VALGRIND_TOOL_VERSION ERROR_VARIABLE VALGRIND_TOOL_VERSION)
string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" VALGRIND_TOOL_VERSION "${VALGRIND_TOOL_VERSION}")
message(STATUS "🔖 Valgrind ${VALGRIND_TOOL_VERSION} (${VALGRIND_TOOL})")

find_program(GENHTML_TOOL NAMES genhtml)
find_program(PLOG_CONVERTER_TOOL NAMES plog-converter)
find_program(PVS_STUDIO_ANALYZER_TOOL NAMES pvs-studio-analyzer)
find_program(SCAN_BUILD_TOOL NAMES scan-build-15 scan-build-14 scan-build-13 scan-build-12 scan-build-11 scan-build)

# the individual source files
file(GLOB_RECURSE SRC_FILES ${PROJECT_SOURCE_DIR}/include/nlohmann/*.hpp)

###############################################################################
# Thorough check with recent compilers
###############################################################################

# Ignored Clang warnings:
# -Wno-c++98-compat               The library targets C++11.
# -Wno-c++98-compat-pedantic      The library targets C++11.
# -Wno-deprecated-declarations    The library contains annotations for deprecated functions.
# -Wno-extra-semi-stmt            The library uses std::assert which triggers this warning.
# -Wno-padded                     We do not care about padding warnings.
# -Wno-covered-switch-default     All switches list all cases and a default case.
# -Wno-unsafe-buffer-usage        Otherwise Doctest would not compile.
# -Wno-weak-vtables               The library is header-only.
# -Wreserved-identifier           See https://github.com/onqtam/doctest/issues/536.

set(CLANG_CXXFLAGS
    -Werror
    -Weverything
    -Wno-c++98-compat
    -Wno-c++98-compat-pedantic
    -Wno-deprecated-declarations
    -Wno-extra-semi-stmt
    -Wno-padded
    -Wno-covered-switch-default
    -Wno-unsafe-buffer-usage
    -Wno-weak-vtables
    -Wno-reserved-identifier
)

# Warning flags determined for GCC 13.0 (experimental) with https://github.com/nlohmann/gcc_flags:
# Ignored GCC warnings:
# -Wno-abi-tag                    We do not care about ABI tags.
# -Wno-aggregate-return           The library uses aggregate returns.
# -Wno-long-long                  The library uses the long long type to interface with system functions.
# -Wno-namespaces                 The library uses namespaces.
# -Wno-padded                     We do not care about padding warnings.
# -Wno-system-headers             We do not care about warnings in system headers.
# -Wno-templates                  The library uses templates.

set(GCC_CXXFLAGS
    -pedantic
    -Werror
    --all-warnings
    --extra-warnings
    -W
    -WNSObject-attribute
    -Wno-abi-tag
    -Waddress
    -Waddress-of-packed-member
    -Wno-aggregate-return
    -Waggressive-loop-optimizations
    -Waligned-new=all
    -Wall
    -Walloc-zero
    -Walloca
    -Wanalyzer-double-fclose
    -Wanalyzer-double-free
    -Wanalyzer-exposure-through-output-file
    -Wanalyzer-file-leak
    -Wanalyzer-free-of-non-heap
    -Wanalyzer-malloc-leak
    -Wanalyzer-mismatching-deallocation
    -Wanalyzer-null-argument
    -Wanalyzer-null-dereference
    -Wanalyzer-possible-null-argument
    -Wanalyzer-possible-null-dereference
    -Wanalyzer-shift-count-negative
    -Wanalyzer-shift-count-overflow
    -Wanalyzer-stale-setjmp-buffer
    -Wanalyzer-tainted-allocation-size
    -Wanalyzer-tainted-array-index
    -Wanalyzer-tainted-divisor
    -Wanalyzer-tainted-offset
    -Wanalyzer-tainted-size
    -Wanalyzer-too-complex
    -Wanalyzer-unsafe-call-within-signal-handler
    -Wanalyzer-use-after-free
    -Wanalyzer-use-of-pointer-in-stale-stack-frame
    -Wanalyzer-use-of-uninitialized-value
    -Wanalyzer-va-arg-type-mismatch
    -Wanalyzer-va-list-exhausted
    -Wanalyzer-va-list-leak
    -Wanalyzer-va-list-use-after-va-end
    -Wanalyzer-write-to-const
    -Wanalyzer-write-to-string-literal
    -Warith-conversion
    -Warray-bounds=2
    -Warray-compare
    -Warray-parameter=2
    -Wattribute-alias=2
    -Wattribute-warning
    -Wattributes
    -Wbool-compare
    -Wbool-operation
    -Wbuiltin-declaration-mismatch
    -Wbuiltin-macro-redefined
    -Wc++0x-compat
    -Wc++11-compat
    -Wc++11-extensions
    -Wc++14-compat
    -Wc++14-extensions
    -Wc++17-compat
    -Wc++17-extensions
    -Wc++1z-compat
    -Wc++20-compat
    -Wc++20-extensions
    -Wc++23-extensions
    -Wc++2a-compat
    -Wcannot-profile
    -Wcast-align
    -Wcast-align=strict
    -Wcast-function-type
    -Wcast-qual
    -Wcatch-value=3
    -Wchar-subscripts
    -Wclass-conversion
    -Wclass-memaccess
    -Wclobbered
    -Wcomma-subscript
    -Wcomment
    -Wcomments
    -Wconditionally-supported
    -Wconversion
    -Wconversion-null
    -Wcoverage-invalid-line-number
    -Wcoverage-mismatch
    -Wcpp
    -Wctad-maybe-unsupported
    -Wctor-dtor-privacy
    -Wdangling-else
    -Wdangling-pointer=2
    -Wdate-time
    -Wdelete-incomplete
    -Wdelete-non-virtual-dtor
    -Wdeprecated
    -Wdeprecated-copy
    -Wdeprecated-copy-dtor
    -Wdeprecated-declarations
    -Wdeprecated-enum-enum-conversion
    -Wdeprecated-enum-float-conversion
    -Wdisabled-optimization
    -Wdiv-by-zero
    -Wdouble-promotion
    -Wduplicated-branches
    -Wduplicated-cond
    -Weffc++
    -Wempty-body
    -Wendif-labels
    -Wenum-compare
    -Wenum-conversion
    -Wexceptions
    -Wexpansion-to-defined
    -Wextra
    -Wextra-semi
    -Wfloat-conversion
    -Wfloat-equal
    -Wformat-diag
    -Wformat-overflow=2
    -Wformat-signedness
    -Wformat-truncation=2
    -Wformat=2
    -Wframe-address
    -Wfree-nonheap-object
    -Whsa
    -Wif-not-aligned
    -Wignored-attributes
    -Wignored-qualifiers
    -Wimplicit-fallthrough=5
    -Winaccessible-base
    -Winfinite-recursion
    -Winherited-variadic-ctor
    -Winit-list-lifetime
    -Winit-self
    -Winline
    -Wint-in-bool-context
    -Wint-to-pointer-cast
    -Winterference-size
    -Winvalid-imported-macros
    -Winvalid-memory-model
    -Winvalid-offsetof
    -Winvalid-pch
    -Wliteral-suffix
    -Wlogical-not-parentheses
    -Wlogical-op
    -Wno-long-long
    -Wlto-type-mismatch
    -Wmain
    -Wmaybe-uninitialized
    -Wmemset-elt-size
    -Wmemset-transposed-args
    -Wmisleading-indentation
    -Wmismatched-dealloc
    -Wmismatched-new-delete
    -Wmismatched-tags
    -Wmissing-attributes
    -Wmissing-braces
    -Wmissing-declarations
    -Wmissing-field-initializers
    -Wmissing-include-dirs
    -Wmissing-profile
    -Wmissing-requires
    -Wmissing-template-keyword
    -Wmultichar
    -Wmultiple-inheritance
    -Wmultistatement-macros
    -Wno-namespaces
    -Wnarrowing
    -Wnoexcept
    -Wnoexcept-type
    -Wnon-template-friend
    -Wnon-virtual-dtor
    -Wnonnull
    -Wnonnull-compare
    -Wnormalized=nfkc
    -Wnull-dereference
    -Wodr
    -Wold-style-cast
    -Wopenacc-parallelism
    -Wopenmp-simd
    -Woverflow
    -Woverlength-strings
    -Woverloaded-virtual
    -Wpacked
    -Wpacked-bitfield-compat
    -Wpacked-not-aligned
    -Wno-padded
    -Wparentheses
    -Wpedantic
    -Wpessimizing-move
    -Wplacement-new=2
    -Wpmf-conversions
    -Wpointer-arith
    -Wpointer-compare
    -Wpragmas
    -Wprio-ctor-dtor
    -Wpsabi
    -Wrange-loop-construct
    -Wredundant-decls
    -Wredundant-move
    -Wredundant-tags
    -Wregister
    -Wreorder
    -Wrestrict
    -Wreturn-local-addr
    -Wreturn-type
    -Wscalar-storage-order
    -Wsequence-point
    -Wshadow=compatible-local
    -Wshadow=global
    -Wshadow=local
    -Wshift-count-negative
    -Wshift-count-overflow
    -Wshift-negative-value
    -Wshift-overflow=2
    -Wsign-compare
    -Wsign-conversion
    -Wsign-promo
    -Wsized-deallocation
    -Wsizeof-array-argument
    -Wsizeof-array-div
    -Wsizeof-pointer-div
    -Wsizeof-pointer-memaccess
    -Wstack-protector
    -Wstrict-aliasing=3
    -Wstrict-null-sentinel
    -Wno-strict-overflow
    -Wstring-compare
    -Wstringop-overflow=4
    -Wstringop-overread
    -Wstringop-truncation
    -Wsubobject-linkage
    -Wsuggest-attribute=cold
    -Wsuggest-attribute=const
    -Wsuggest-attribute=format
    -Wsuggest-attribute=malloc
    -Wsuggest-attribute=noreturn
    -Wsuggest-attribute=pure
    -Wsuggest-final-methods
    -Wsuggest-final-types
    -Wsuggest-override
    -Wswitch
    -Wswitch-bool
    -Wswitch-default
    -Wswitch-enum
    -Wswitch-outside-range
    -Wswitch-unreachable
    -Wsync-nand
    -Wsynth
    -Wno-system-headers
    -Wtautological-compare
    -Wno-templates
    -Wterminate
    -Wtrampolines
    -Wtrigraphs
    -Wtrivial-auto-var-init
    -Wtsan
    -Wtype-limits
    -Wundef
    -Wuninitialized
    -Wunknown-pragmas
    -Wunreachable-code
    -Wunsafe-loop-optimizations
    -Wunused
    -Wunused-but-set-parameter
    -Wunused-but-set-variable
    -Wunused-const-variable=2
    -Wunused-function
    -Wunused-label
    -Wunused-local-typedefs
    -Wunused-macros
    -Wunused-parameter
    -Wunused-result
    -Wunused-value
    -Wunused-variable
    -Wuse-after-free=3
    -Wuseless-cast
    -Wvarargs
    -Wvariadic-macros
    -Wvector-operation-performance
    -Wvexing-parse
    -Wvirtual-inheritance
    -Wvirtual-move-assign
    -Wvla
    -Wvla-parameter
    -Wvolatile
    -Wvolatile-register-var
    -Wwrite-strings
    -Wzero-as-null-pointer-constant
    -Wzero-length-bounds
)

add_custom_target(ci_test_gcc
    COMMAND CXX=${GCC_TOOL} CXXFLAGS="${GCC_CXXFLAGS}" ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_gcc
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_gcc
    COMMAND cd ${PROJECT_BINARY_DIR}/build_gcc && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with GCC using maximal warning flags"
)

add_custom_target(ci_test_clang
    COMMAND CXX=${CLANG_TOOL} CXXFLAGS="${CLANG_CXXFLAGS}" ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang
    COMMAND cd ${PROJECT_BINARY_DIR}/build_clang && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with Clang using maximal warning flags"
)

###############################################################################
# Different C++ Standards.
###############################################################################

foreach(CXX_STANDARD 11 14 17 20 23)
    add_custom_target(ci_test_gcc_cxx${CXX_STANDARD}
        COMMAND CXX=${GCC_TOOL} CXXFLAGS="${GCC_CXXFLAGS}" ${CMAKE_COMMAND}
            -DCMAKE_BUILD_TYPE=Debug -GNinja
            -DJSON_BuildTests=ON -DJSON_FastTests=ON
            -DJSON_TestStandards=${CXX_STANDARD}
            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_gcc_cxx${CXX_STANDARD}
        COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_gcc_cxx${CXX_STANDARD}
        COMMAND cd ${PROJECT_BINARY_DIR}/build_gcc_cxx${CXX_STANDARD} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
        COMMENT "Compile and test with GCC for C++${CXX_STANDARD}"
    )

    add_custom_target(ci_test_clang_cxx${CXX_STANDARD}
        COMMAND CXX=${CLANG_TOOL} CXXFLAGS="${CLANG_CXXFLAGS}" ${CMAKE_COMMAND}
            -DCMAKE_BUILD_TYPE=Debug -GNinja
            -DJSON_BuildTests=ON -DJSON_FastTests=ON
            -DJSON_TestStandards=${CXX_STANDARD}
            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD}
        COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD}
        COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
        COMMENT "Compile and test with Clang for C++${CXX_STANDARD}"
    )

    add_custom_target(ci_test_clang_libcxx_cxx${CXX_STANDARD}
        COMMAND CXX=${CLANG_TOOL} CXXFLAGS="${CLANG_CXXFLAGS}" ${CMAKE_COMMAND}
            -DCMAKE_BUILD_TYPE=Debug -GNinja
            -DJSON_BuildTests=ON -DJSON_FastTests=ON
            -DJSON_TestStandards=${CXX_STANDARD}
            -DCMAKE_CXX_FLAGS="-stdlib=libc++"
            -DCMAKE_EXE_LINKER_FLAGS="-lc++abi"
            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD}
        COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD}
        COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
        COMMENT "Compile and test with Clang for C++${CXX_STANDARD} (libc++)"
    )
endforeach()

###############################################################################
# Disable exceptions.
###############################################################################

add_custom_target(ci_test_noexceptions
    COMMAND ${CMAKE_COMMAND}
    -DCMAKE_BUILD_TYPE=Debug -GNinja
    -DJSON_BuildTests=ON -DCMAKE_CXX_FLAGS=-DJSON_NOEXCEPTION -DDOCTEST_TEST_FILTER=--no-throw
    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_noexceptions
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_noexceptions
    COMMAND cd ${PROJECT_BINARY_DIR}/build_noexceptions && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with exceptions switched off"
)

###############################################################################
# Disable implicit conversions.
###############################################################################

add_custom_target(ci_test_noimplicitconversions
    COMMAND ${CMAKE_COMMAND}
    -DCMAKE_BUILD_TYPE=Debug -GNinja
    -DJSON_BuildTests=ON -DJSON_ImplicitConversions=OFF
    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_noimplicitconversions
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_noimplicitconversions
    COMMAND cd ${PROJECT_BINARY_DIR}/build_noimplicitconversions && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with implicit conversions switched off"
)

###############################################################################
# Enable improved diagnostics.
###############################################################################

add_custom_target(ci_test_diagnostics
    COMMAND ${CMAKE_COMMAND}
    -DCMAKE_BUILD_TYPE=Debug -GNinja
    -DJSON_BuildTests=ON -DJSON_Diagnostics=ON
    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_diagnostics
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_diagnostics
    COMMAND cd ${PROJECT_BINARY_DIR}/build_diagnostics && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with improved diagnostics enabled"
)

###############################################################################
# Enable legacy discarded value comparison.
###############################################################################

add_custom_target(ci_test_legacycomparison
    COMMAND ${CMAKE_COMMAND}
    -DCMAKE_BUILD_TYPE=Debug -GNinja
    -DJSON_BuildTests=ON -DJSON_LegacyDiscardedValueComparison=ON
    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_legacycomparison
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_legacycomparison
    COMMAND cd ${PROJECT_BINARY_DIR}/build_legacycomparison && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with legacy discarded value comparison enabled"
)

###############################################################################
# Disable global UDLs.
###############################################################################

add_custom_target(ci_test_noglobaludls
    COMMAND ${CMAKE_COMMAND}
    -DCMAKE_BUILD_TYPE=Debug -GNinja
    -DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_GlobalUDLs=OFF
    -DCMAKE_CXX_FLAGS=-DJSON_TEST_NO_GLOBAL_UDLS
    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_noglobaludls
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_noglobaludls
    COMMAND cd ${PROJECT_BINARY_DIR}/build_noglobaludls && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with global UDLs disabled"
)

###############################################################################
# Coverage.
###############################################################################

add_custom_target(ci_test_coverage
    COMMAND CXX=g++ ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja -DCMAKE_CXX_FLAGS="--coverage;-fprofile-arcs;-ftest-coverage"
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_coverage
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_coverage
    COMMAND cd ${PROJECT_BINARY_DIR}/build_coverage && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure

    COMMAND CXX=g++ ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja -DCMAKE_CXX_FLAGS="-m32;--coverage;-fprofile-arcs;-ftest-coverage"
        -DJSON_BuildTests=ON -DJSON_32bitTest=ONLY
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_coverage32
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_coverage32
    COMMAND cd ${PROJECT_BINARY_DIR}/build_coverage32 && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure

    COMMAND ${LCOV_TOOL} --directory . --capture --output-file json.info --rc lcov_branch_coverage=1
    COMMAND ${LCOV_TOOL} -e json.info ${SRC_FILES} --output-file json.info.filtered --rc lcov_branch_coverage=1
    COMMAND ${CMAKE_SOURCE_DIR}/tests/thirdparty/imapdl/filterbr.py json.info.filtered > json.info.filtered.noexcept
    COMMAND genhtml --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage json.info.filtered.noexcept

    COMMENT "Compile and test with coverage"
)

###############################################################################
# Sanitizers.
###############################################################################

set(CLANG_CXX_FLAGS_SANITIZER "-g -O1 -fsanitize=address -fsanitize=undefined -fsanitize=integer -fsanitize=nullability -fno-omit-frame-pointer -fno-sanitize-recover=all -fno-sanitize=unsigned-integer-overflow -fno-sanitize=unsigned-shift-base")

add_custom_target(ci_test_clang_sanitizer
    COMMAND CXX=${CLANG_TOOL} CXXFLAGS=${CLANG_CXX_FLAGS_SANITIZER} ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_sanitizer
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang_sanitizer
    COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_sanitizer && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test with sanitizers"
)

###############################################################################
# Check if header is amalgamated and sources are properly indented.
###############################################################################

set(ASTYLE_FLAGS --style=allman --indent=spaces=4 --indent-modifiers --indent-switches --indent-preproc-block --indent-preproc-define --indent-col1-comments --pad-oper --pad-header --align-pointer=type --align-reference=type --add-brackets --convert-tabs --close-templates --lineend=linux --preserve-date --formatted)

file(GLOB_RECURSE INDENT_FILES
    ${PROJECT_SOURCE_DIR}/include/nlohmann/*.hpp
        ${PROJECT_SOURCE_DIR}/tests/src/*.cpp
        ${PROJECT_SOURCE_DIR}/tests/src/*.hpp
        ${PROJECT_SOURCE_DIR}/tests/benchmarks/src/benchmarks.cpp
    ${PROJECT_SOURCE_DIR}/docs/examples/*.cpp
)

set(include_dir ${PROJECT_SOURCE_DIR}/single_include/nlohmann)
set(tool_dir ${PROJECT_SOURCE_DIR}/tools/amalgamate)
add_custom_target(ci_test_amalgamation
    COMMAND rm -fr ${include_dir}/json.hpp~ ${include_dir}/json_fwd.hpp~
    COMMAND cp ${include_dir}/json.hpp ${include_dir}/json.hpp~
    COMMAND cp ${include_dir}/json_fwd.hpp ${include_dir}/json_fwd.hpp~

    COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json.json -s .
    COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json_fwd.json -s .
    COMMAND ${ASTYLE_TOOL} ${ASTYLE_FLAGS} --suffix=none --quiet ${include_dir}/json.hpp ${include_dir}/json_fwd.hpp

    COMMAND diff ${include_dir}/json.hpp~ ${include_dir}/json.hpp
    COMMAND diff ${include_dir}/json_fwd.hpp~ ${include_dir}/json_fwd.hpp

    COMMAND ${ASTYLE_TOOL} ${ASTYLE_FLAGS} ${INDENT_FILES}
    COMMAND for FILE in `find . -name '*.orig'`\; do false \; done

    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
    COMMENT "Check amalgamation and indentation"
)

###############################################################################
# Build and test using the amalgamated header
###############################################################################

add_custom_target(ci_test_single_header
    COMMAND CXX=${GCC_TOOL} CXXFLAGS="${GCC_CXXFLAGS}" ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON -DJSON_MultipleHeaders=OFF -DJSON_FastTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_single_header
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_single_header
    COMMAND cd ${PROJECT_BINARY_DIR}/build_single_header && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Compile and test single-header version"
)

###############################################################################
# Valgrind.
###############################################################################

add_custom_target(ci_test_valgrind
    COMMAND CXX=${GCC_TOOL} ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON -DJSON_Valgrind=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_valgrind
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_valgrind
    COMMAND cd ${PROJECT_BINARY_DIR}/build_valgrind && ${CMAKE_CTEST_COMMAND} -L valgrind --parallel ${N} --output-on-failure
    COMMENT "Compile and test with Valgrind"
)

###############################################################################
# Check code with Clang Static Analyzer.
###############################################################################

set(CLANG_ANALYZER_CHECKS "fuchsia.HandleChecker,nullability.NullableDereferenced,nullability.NullablePassedToNonnull,nullability.NullableReturnedFromNonnull,optin.cplusplus.UninitializedObject,optin.cplusplus.VirtualCall,optin.mpi.MPI-Checker,optin.osx.OSObjectCStyleCast,optin.osx.cocoa.localizability.EmptyLocalizationContextChecker,optin.osx.cocoa.localizability.NonLocalizedStringChecker,optin.performance.GCDAntipattern,optin.performance.Padding,optin.portability.UnixAPI,security.FloatLoopCounter,security.insecureAPI.DeprecatedOrUnsafeBufferHandling,security.insecureAPI.bcmp,security.insecureAPI.bcopy,security.insecureAPI.bzero,security.insecureAPI.rand,security.insecureAPI.strcpy,valist.CopyToSelf,valist.Uninitialized,valist.Unterminated,webkit.NoUncountedMemberChecker,webkit.RefCntblBaseVirtualDtor,core.CallAndMessage,core.DivideZero,core.NonNullParamChecker,core.NullDereference,core.StackAddressEscape,core.UndefinedBinaryOperatorResult,core.VLASize,core.uninitialized.ArraySubscript,core.uninitialized.Assign,core.uninitialized.Branch,core.uninitialized.CapturedBlockVariable,core.uninitialized.UndefReturn,cplusplus.InnerPointer,cplusplus.Move,cplusplus.NewDelete,cplusplus.NewDeleteLeaks,cplusplus.PlacementNew,cplusplus.PureVirtualCall,deadcode.DeadStores,nullability.NullPassedToNonnull,nullability.NullReturnedFromNonnull,osx.API,osx.MIG,osx.NumberObjectConversion,osx.OSObjectRetainCount,osx.ObjCProperty,osx.SecKeychainAPI,osx.cocoa.AtSync,osx.cocoa.AutoreleaseWrite,osx.cocoa.ClassRelease,osx.cocoa.Dealloc,osx.cocoa.IncompatibleMethodTypes,osx.cocoa.Loops,osx.cocoa.MissingSuperCall,osx.cocoa.NSAutoreleasePool,osx.cocoa.NSError,osx.cocoa.NilArg,osx.cocoa.NonNilReturnValue,osx.cocoa.ObjCGenerics,osx.cocoa.RetainCount,osx.cocoa.RunLoopAutoreleaseLeak,osx.cocoa.SelfInit,osx.cocoa.SuperDealloc,osx.cocoa.UnusedIvars,osx.cocoa.VariadicMethodTypes,osx.coreFoundation.CFError,osx.coreFoundation.CFNumber,osx.coreFoundation.CFRetainRelease,osx.coreFoundation.containers.OutOfBounds,osx.coreFoundation.containers.PointerSizedValues,security.insecureAPI.UncheckedReturn,security.insecureAPI.decodeValueOfObjCType,security.insecureAPI.getpw,security.insecureAPI.gets,security.insecureAPI.mkstemp,security.insecureAPI.mktemp,security.insecureAPI.vfork,unix.API,unix.Malloc,unix.MallocSizeof,unix.MismatchedDeallocator,unix.Vfork,unix.cstring.BadSizeArg,unix.cstring.NullArg")

add_custom_target(ci_clang_analyze
    COMMAND CXX=${CLANG_TOOL} ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_analyze
    COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_analyze && ${SCAN_BUILD_TOOL} -enable-checker ${CLANG_ANALYZER_CHECKS} --use-c++=${CLANG_TOOL} -analyze-headers -o ${PROJECT_BINARY_DIR}/report ninja
    COMMENT "Check code with Clang Analyzer"
)

###############################################################################
# Check code with Cppcheck.
###############################################################################

add_custom_target(ci_cppcheck
    COMMAND ${CPPCHECK_TOOL} --enable=warning --suppress=missingReturn --inline-suppr --inconclusive --force --std=c++11 ${PROJECT_SOURCE_DIR}/single_include/nlohmann/json.hpp --error-exitcode=1
    COMMENT "Check code with Cppcheck"
)

###############################################################################
# Check code with cpplint.
###############################################################################

add_custom_target(ci_cpplint
    COMMAND ${Python3_EXECUTABLE} -mvenv venv_cpplint
    COMMAND venv_cpplint/bin/pip3 --quiet install cpplint
    COMMAND venv_cpplint/bin/cpplint --filter=-whitespace,-legal,-runtime/references,-runtime/explicit,-runtime/indentation_namespace,-readability/casting,-readability/nolint --quiet --recursive ${SRC_FILES}
    COMMENT "Check code with cpplint"
    WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
)

###############################################################################
# Check code with OCLint.
###############################################################################

file(COPY ${PROJECT_SOURCE_DIR}/single_include/nlohmann/json.hpp DESTINATION ${PROJECT_BINARY_DIR}/src_single)
file(RENAME ${PROJECT_BINARY_DIR}/src_single/json.hpp ${PROJECT_BINARY_DIR}/src_single/all.cpp)
file(APPEND "${PROJECT_BINARY_DIR}/src_single/all.cpp" "\n\nint main()\n{}\n")

add_executable(single_all ${PROJECT_BINARY_DIR}/src_single/all.cpp)
target_compile_features(single_all PRIVATE cxx_std_11)

add_custom_target(ci_oclint
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug
        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
        -DJSON_BuildTests=OFF -DJSON_CI=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_oclint
    COMMAND ${OCLINT_TOOL} -i ${PROJECT_BINARY_DIR}/build_oclint/src_single/all.cpp -p ${PROJECT_BINARY_DIR}/build_oclint --
        -report-type html -enable-global-analysis --max-priority-1=0 --max-priority-2=1000 --max-priority-3=2000
        --disable-rule=MultipleUnaryOperator
        --disable-rule=DoubleNegative
        --disable-rule=ShortVariableName
        --disable-rule=GotoStatement
        --disable-rule=LongLine
        -o ${PROJECT_BINARY_DIR}/build_oclint/oclint_report.html
    COMMENT "Check code with OCLint"
)

###############################################################################
# Check code with Clang-Tidy.
###############################################################################

add_custom_target(ci_clang_tidy
    COMMAND CXX=${CLANG_TOOL} ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_CXX_CLANG_TIDY=${CLANG_TIDY_TOOL}
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_tidy
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang_tidy
    COMMENT "Check code with Clang-Tidy"
)

###############################################################################
# Check code with PVS-Studio Analyzer <https://www.viva64.com/en/pvs-studio/>.
###############################################################################

add_custom_target(ci_pvs_studio
    COMMAND CXX=${CLANG_TOOL} ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug
        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
        -DJSON_BuildTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_pvs_studio
    COMMAND cd ${PROJECT_BINARY_DIR}/build_pvs_studio && ${PVS_STUDIO_ANALYZER_TOOL} analyze -j 10
    COMMAND cd ${PROJECT_BINARY_DIR}/build_pvs_studio && ${PLOG_CONVERTER_TOOL} -a'GA:1,2;64:1;CS' -t fullhtml PVS-Studio.log -o pvs
    COMMENT "Check code with PVS Studio"
)

###############################################################################
# Check code with Infer <https://fbinfer.com> static analyzer.
###############################################################################

add_custom_target(ci_infer
    COMMAND mkdir -p ${PROJECT_BINARY_DIR}/build_infer
    COMMAND cd ${PROJECT_BINARY_DIR}/build_infer && ${INFER_TOOL} compile -- ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=Debug ${PROJECT_SOURCE_DIR} -DJSON_BuildTests=ON
    COMMAND cd ${PROJECT_BINARY_DIR}/build_infer && ${INFER_TOOL} run -- make
    COMMENT "Check code with Infer"
)

###############################################################################
# Run test suite with previously downloaded test data.
###############################################################################

add_custom_target(ci_offline_testdata
    COMMAND mkdir -p ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data
    COMMAND cd ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data && ${GIT_TOOL} clone -c advice.detachedHead=false --branch v3.1.0 https://github.com/nlohmann/json_test_data.git --quiet --depth 1
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_TestDataDirectory=${PROJECT_BINARY_DIR}/build_offline_testdata/test_data/json_test_data
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_offline_testdata
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_offline_testdata
    COMMAND cd ${PROJECT_BINARY_DIR}/build_offline_testdata && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
    COMMENT "Check code with previously downloaded test data"
)

###############################################################################
# Run test suite when project was not checked out from Git
###############################################################################

add_custom_target(ci_non_git_tests
    COMMAND git config --global --add safe.directory ${PROJECT_SOURCE_DIR}
    COMMAND mkdir -p ${PROJECT_BINARY_DIR}/build_non_git_tests/sources
    COMMAND cd ${PROJECT_SOURCE_DIR} && for FILE in `${GIT_TOOL} ls-tree --name-only HEAD`\; do cp -r $$FILE ${PROJECT_BINARY_DIR}/build_non_git_tests/sources \; done
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON -DJSON_FastTests=ON
        -S${PROJECT_BINARY_DIR}/build_non_git_tests/sources -B${PROJECT_BINARY_DIR}/build_non_git_tests
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_non_git_tests
    COMMAND cd ${PROJECT_BINARY_DIR}/build_non_git_tests && ${CMAKE_CTEST_COMMAND} --parallel ${N} -LE git_required --output-on-failure
    COMMENT "Check code when project was not checked out from Git"
)

###############################################################################
# Run test suite and exclude tests that change installed files
###############################################################################

add_custom_target(ci_reproducible_tests
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON -DJSON_FastTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_reproducible_tests
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_reproducible_tests
    COMMAND cd ${PROJECT_BINARY_DIR}/build_reproducible_tests && ${CMAKE_CTEST_COMMAND} --parallel ${N} -LE not_reproducible --output-on-failure
    COMMENT "Check code and exclude tests that change installed files"
)

###############################################################################
# Check if every header in the include folder includes sufficient headers to
# be compiled individually.
###############################################################################

set(iwyu_path_and_options ${IWYU_TOOL} -Xiwyu --max_line_length=300)

foreach(SRC_FILE ${SRC_FILES})
    # get relative path of the header file
    file(RELATIVE_PATH RELATIVE_SRC_FILE "${PROJECT_SOURCE_DIR}/include/nlohmann" "${SRC_FILE}")
    # replace slashes and strip suffix
    string(REPLACE "/" "_" RELATIVE_SRC_FILE "${RELATIVE_SRC_FILE}")
    string(REPLACE ".hpp" "" RELATIVE_SRC_FILE "${RELATIVE_SRC_FILE}")
    # create code file
    file(WRITE "${PROJECT_BINARY_DIR}/src_single/${RELATIVE_SRC_FILE}.cpp" "#include \"${SRC_FILE}\" // IWYU pragma: keep\n\nint main()\n{}\n")
    # create executable
    add_executable(single_${RELATIVE_SRC_FILE} EXCLUDE_FROM_ALL ${PROJECT_BINARY_DIR}/src_single/${RELATIVE_SRC_FILE}.cpp)
    target_include_directories(single_${RELATIVE_SRC_FILE} PRIVATE ${PROJECT_SOURCE_DIR}/include)
    target_compile_features(single_${RELATIVE_SRC_FILE} PRIVATE cxx_std_11)
    set_property(TARGET single_${RELATIVE_SRC_FILE} PROPERTY CXX_INCLUDE_WHAT_YOU_USE "${iwyu_path_and_options}")
    # remember binary for ci_single_binaries target
    list(APPEND single_binaries single_${RELATIVE_SRC_FILE})
endforeach()

add_custom_target(ci_single_binaries
    DEPENDS ${single_binaries}
    COMMENT "Check if headers are self-contained"
)

###############################################################################
# Benchmarks
###############################################################################

add_custom_target(ci_benchmarks
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Release -GNinja
        -S${PROJECT_SOURCE_DIR}/benchmarks -B${PROJECT_BINARY_DIR}/build_benchmarks
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_benchmarks --target json_benchmarks
    COMMAND cd ${PROJECT_BINARY_DIR}/build_benchmarks && ./json_benchmarks
    COMMENT "Run benchmarks"
)

###############################################################################
# CMake flags
###############################################################################

function(ci_get_cmake version var)
    set(${var} ${PROJECT_BINARY_DIR}/cmake-${version}/bin/cmake)
    add_custom_command(
        OUTPUT ${${var}}
        COMMAND wget -nc https://github.com/Kitware/CMake/releases/download/v${version}/cmake-${version}.tar.gz
        COMMAND tar xfz cmake-${version}.tar.gz
        COMMAND rm cmake-${version}.tar.gz
        COMMAND ${CMAKE_COMMAND} -S cmake-${version} -B cmake-${version}
        COMMAND ${CMAKE_COMMAND} --build cmake-${version} --parallel 10
        WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
        COMMENT "Download CMake ${version}"
    )
    set(${var} ${${var}} PARENT_SCOPE)
endfunction()

ci_get_cmake(3.1.0 CMAKE_3_1_0_BINARY)
ci_get_cmake(3.13.0 CMAKE_3_13_0_BINARY)

set(JSON_CMAKE_FLAGS_3_1_0 JSON_Diagnostics JSON_GlobalUDLs JSON_ImplicitConversions JSON_DisableEnumSerialization
    JSON_LegacyDiscardedValueComparison JSON_Install JSON_MultipleHeaders JSON_SystemInclude JSON_Valgrind)
set(JSON_CMAKE_FLAGS_3_13_0 JSON_BuildTests)

function(ci_add_cmake_flags_targets flag min_version)
    string(TOLOWER "ci_cmake_flag_${flag}" flag_target)
    string(REPLACE . _ min_version_var ${min_version})
    set(cmake_binary ${CMAKE_${min_version_var}_BINARY})
    add_custom_target(${flag_target}
        COMMENT "Check CMake flag ${flag} (CMake ${CMAKE_VERSION})"
        COMMAND ${CMAKE_COMMAND}
            -Werror=dev
            -D${flag}=ON
            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_${flag_target}
    )
    add_custom_target(${flag_target}_${min_version_var}
        COMMENT "Check CMake flag ${JSON_CMAKE_FLAG} (CMake ${min_version})"
        COMMAND mkdir -pv ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var}
        COMMAND cd ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var}
            && ${cmake_binary} -Werror=dev ${PROJECT_SOURCE_DIR} -D${flag}=ON
        DEPENDS ${cmake_binary}
    )
    list(APPEND JSON_CMAKE_FLAG_TARGETS ${JSON_CMAKE_FLAG_TARGET} ${flag_target}_${min_version_var})
    list(APPEND JSON_CMAKE_FLAG_BUILD_DIRS ${PROJECT_BINARY_DIR}/build_${flag_target} ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var})
    set(JSON_CMAKE_FLAG_TARGETS ${JSON_CMAKE_FLAG_TARGETS} PARENT_SCOPE)
    set(JSON_CMAKE_FLAG_BUILD_DIRS ${JSON_CMAKE_FLAG_BUILD_DIRS} PARENT_SCOPE)
endfunction()

foreach(JSON_CMAKE_FLAG ${JSON_CMAKE_FLAGS_3_1_0})
    ci_add_cmake_flags_targets(${JSON_CMAKE_FLAG} 3.1.0)
endforeach()

foreach(JSON_CMAKE_FLAG ${JSON_CMAKE_FLAGS_3_13_0})
    ci_add_cmake_flags_targets(${JSON_CMAKE_FLAG} 3.13.0)
endforeach()

add_custom_target(ci_cmake_flags
    DEPENDS ${JSON_CMAKE_FLAG_TARGETS}
    COMMENT "Check CMake flags"
)

###############################################################################
# Use more installed compilers.
###############################################################################

foreach(COMPILER g++-4.8 g++-4.9 g++-5 g++-6 g++-7 g++-8 g++-9 g++-10 g++-11 clang++-3.5 clang++-3.6 clang++-3.7 clang++-3.8 clang++-3.9 clang++-4.0 clang++-5.0 clang++-6.0 clang++-7 clang++-8 clang++-9 clang++-10 clang++-11 clang++-12 clang++-13 clang++-14 clang++-15 clang++-16 clang++-17 clang++-18 clang++-19 clang++-20)
    find_program(COMPILER_TOOL NAMES ${COMPILER})
    if (COMPILER_TOOL)
        unset(ADDITIONAL_FLAGS)

        add_custom_target(ci_test_compiler_${COMPILER}
            COMMAND CXX=${COMPILER} ${CMAKE_COMMAND}
                -DCMAKE_BUILD_TYPE=Debug -GNinja
                -DJSON_BuildTests=ON -DJSON_FastTests=ON
                -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_compiler_${COMPILER}
                ${ADDITIONAL_FLAGS}
            COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_compiler_${COMPILER}
            COMMAND cd ${PROJECT_BINARY_DIR}/build_compiler_${COMPILER} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --exclude-regex "test-unicode" --output-on-failure
            COMMENT "Compile and test with ${COMPILER}"
        )
    endif()
    unset(COMPILER_TOOL CACHE)
endforeach()

add_custom_target(ci_test_compiler_default
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DJSON_BuildTests=ON -DJSON_FastTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_compiler_default
        ${ADDITIONAL_FLAGS}
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_compiler_default --parallel ${N}
    COMMAND cd ${PROJECT_BINARY_DIR}/build_compiler_default && ${CMAKE_CTEST_COMMAND} --parallel ${N} --exclude-regex "test-unicode" -LE git_required --output-on-failure
    COMMENT "Compile and test with default C++ compiler"
)

###############################################################################
# CUDA example
###############################################################################

add_custom_target(ci_cuda_example
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DCMAKE_CUDA_HOST_COMPILER=g++-8
        -S${PROJECT_SOURCE_DIR}/tests/cuda_example -B${PROJECT_BINARY_DIR}/build_cuda_example
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_cuda_example
)

###############################################################################
# Intel C++ Compiler
###############################################################################

add_custom_target(ci_icpc
    COMMAND ${CMAKE_COMMAND}
        -DCMAKE_BUILD_TYPE=Debug -GNinja
        -DCMAKE_C_COMPILER=icc -DCMAKE_CXX_COMPILER=icpc
        -DJSON_BuildTests=ON -DJSON_FastTests=ON
        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_icpc
    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_icpc
    COMMAND cd ${PROJECT_BINARY_DIR}/build_icpc && ${CMAKE_CTEST_COMMAND} --parallel ${N} --exclude-regex "test-unicode" --output-on-failure
    COMMENT "Compile and test with ICPC"
)

###############################################################################
# test documentation
###############################################################################

add_custom_target(ci_test_examples
    COMMAND make CXX="${GCC_TOOL}" check_output_portable -j8
    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/docs
    COMMENT "Check that all examples compile and create the desired output"
)

add_custom_target(ci_test_api_documentation
    COMMAND ${Python3_EXECUTABLE} scripts/check_structure.py
    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/docs/mkdocs
    COMMENT "Lint the API documentation"
)

###############################################################################
# Clean up all generated files.
###############################################################################

add_custom_target(ci_clean
    COMMAND rm -fr ${PROJECT_BINARY_DIR}/build_* cmake-3.1.0-Darwin64 ${JSON_CMAKE_FLAG_BUILD_DIRS} ${single_binaries}
    COMMENT "Clean generated directories"
)