# The MIT License (MIT)
#
# Copyright (c)
#   2013 Matthew Arsenault
#   2015-2016 RWTH Aachen University, Federal Republic of Germany
#   2021 Markus Eggenbauer
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# Helper function to get the language of a source file.
function(sanitizer_lang_of_source FILE RETURN_VAR)
    get_filename_component(LONGEST_EXT "${FILE}" EXT)
    # If extension is empty return. This can happen for extensionless headers
    if("${LONGEST_EXT}" STREQUAL "")
        set(${RETURN_VAR} "" PARENT_SCOPE)
        return()
    endif()
    # Get shortest extension as some files can have dot in their names
    string(REGEX REPLACE "^.*(\\.[^.]+)$" "\\1" FILE_EXT ${LONGEST_EXT})
    string(TOLOWER "${FILE_EXT}" FILE_EXT)
    string(SUBSTRING "${FILE_EXT}" 1 -1 FILE_EXT)

    get_property(ENABLED_LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
    foreach(LANG ${ENABLED_LANGUAGES})
        list(FIND CMAKE_${LANG}_SOURCE_FILE_EXTENSIONS "${FILE_EXT}" TEMP)
        if(NOT ${TEMP} EQUAL -1)
            set(${RETURN_VAR} "${LANG}" PARENT_SCOPE)
            return()
        endif()
    endforeach()

    set(${RETURN_VAR} "" PARENT_SCOPE)
endfunction()

# Helper function to get compilers used by a target.
function(sanitizer_target_compilers TARGET RETURN_VAR)
    # Check if all sources for target use the same compiler. If a target uses
    # e.g. C and Fortran mixed and uses different compilers (e.g. clang and
    # gfortran) this can trigger huge problems, because different compilers may
    # use different implementations for sanitizers.
    set(BUFFER "")
    get_target_property(TSOURCES ${TARGET} SOURCES)
    foreach(FILE ${TSOURCES})
        # If expression was found, FILE is a generator-expression for an object
        # library. Object libraries will be ignored.
        string(REGEX MATCH "TARGET_OBJECTS:([^ >]+)" _file ${FILE})
        if("${_file}" STREQUAL "")
            sanitizer_lang_of_source(${FILE} LANG)
            if(LANG)
                list(APPEND BUFFER ${CMAKE_${LANG}_COMPILER_ID})
            endif()
        endif()
    endforeach()

    list(REMOVE_DUPLICATES BUFFER)
    set(${RETURN_VAR} "${BUFFER}" PARENT_SCOPE)
endfunction()

# Helper function to check compiler flags for language compiler.
function(sanitizer_check_compiler_flag FLAG LANG VARIABLE)
    if(${LANG} STREQUAL "C")
        include(CheckCCompilerFlag)
        check_c_compiler_flag("${FLAG}" ${VARIABLE})

    elseif(${LANG} STREQUAL "CXX")
        include(CheckCXXCompilerFlag)
        check_cxx_compiler_flag("${FLAG}" ${VARIABLE})

    elseif(${LANG} STREQUAL "Fortran")
        # CheckFortranCompilerFlag was introduced in CMake 3.x. To be compatible
        # with older Cmake versions, we will check if this module is present
        # before we use it. Otherwise we will define Fortran coverage support as
        # not available.
        include(CheckFortranCompilerFlag OPTIONAL RESULT_VARIABLE INCLUDED)
        if(INCLUDED)
            CHECK_Fortran_COMPILER_FLAG("${FLAG}" ${VARIABLE})
        elseif(NOT CMAKE_REQUIRED_QUIET)
            message(STATUS "Performing Test ${VARIABLE}")
            message(STATUS "Performing Test ${VARIABLE}" " - Failed (Check not supported)")
        endif()
    endif()
endfunction()

# Helper function to test compiler flags.
function(sanitizer_check_compiler_flags FLAG_CANDIDATES NAME PREFIX)
    set(CMAKE_REQUIRED_QUIET ${${PREFIX}_FIND_QUIETLY})

    get_property(ENABLED_LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
    foreach(LANG ${ENABLED_LANGUAGES})
        # Sanitizer flags are not dependend on language, but the used compiler.
        # So instead of searching flags foreach language, search flags foreach
        # compiler used.
        set(COMPILER ${CMAKE_${LANG}_COMPILER_ID})
        if(NOT DEFINED ${PREFIX}_${COMPILER}_FLAGS)
            foreach(FLAG ${FLAG_CANDIDATES})
                if(NOT CMAKE_REQUIRED_QUIET)
                    message(STATUS "Try ${COMPILER} ${NAME} flag = [${FLAG}]")
                endif()

                set(CMAKE_REQUIRED_FLAGS "${FLAG}")
                unset(${PREFIX}_FLAG_DETECTED CACHE)
                sanitizer_check_compiler_flag("${FLAG}" ${LANG} ${PREFIX}_FLAG_DETECTED)

                if(${PREFIX}_FLAG_DETECTED)
                    # If compiler is a GNU compiler, search for static flag, if
                    # SANITIZE_LINK_STATIC is enabled.
                    if(SANITIZE_LINK_STATIC AND (COMPILER STREQUAL "GNU"))
                        string(TOLOWER ${PREFIX} PREFIX_lower)
                        sanitizer_check_compiler_flag("-static-lib${PREFIX_lower}" ${LANG}
                                                      ${PREFIX}_STATIC_FLAG_DETECTED)

                        if(${PREFIX}_STATIC_FLAG_DETECTED)
                            set(FLAG "-static-lib${PREFIX_lower} ${FLAG}")
                        endif()
                    endif()

                    set(${PREFIX}_${COMPILER}_FLAGS "${FLAG}"
                        CACHE STRING "${NAME} flags for ${COMPILER} compiler.")
                    mark_as_advanced(${PREFIX}_${COMPILER}_FLAGS)
                    break()
                endif()
            endforeach()

            if(NOT ${PREFIX}_FLAG_DETECTED)
                set(${PREFIX}_${COMPILER}_FLAGS "" CACHE STRING
                                                         "${NAME} flags for ${COMPILER} compiler.")
                mark_as_advanced(${PREFIX}_${COMPILER}_FLAGS)

                message(
                    NOTICE "${NAME} is not available for ${COMPILER} "
                    "compiler. Targets using this compiler will be " "compiled without ${NAME}.")
            endif()
        endif()
    endforeach()
endfunction()

# Helper to assign sanitizer flags for TARGET.
function(sanitizer_add_flags TARGET NAME PREFIX)
    # Get list of compilers used by target and check, if sanitizer is available
    # for this target. Other compiler checks like check for conflicting
    # compilers will be done in add_sanitizers function.
    sanitizer_target_compilers(${TARGET} TARGET_COMPILER)
    list(LENGTH TARGET_COMPILER NUM_COMPILERS)
    if("${${PREFIX}_${TARGET_COMPILER}_FLAGS}" STREQUAL "")
        return()
    endif()

    # Set compile- and link-flags for target.
    set_property(TARGET ${TARGET} APPEND_STRING PROPERTY COMPILE_FLAGS
                                                         " ${${PREFIX}_${TARGET_COMPILER}_FLAGS}")
    set_property(TARGET ${TARGET} APPEND_STRING PROPERTY COMPILE_FLAGS
                                                         " ${SanBlist_${TARGET_COMPILER}_FLAGS}")
    set_property(TARGET ${TARGET} APPEND_STRING PROPERTY LINK_FLAGS
                                                         " ${${PREFIX}_${TARGET_COMPILER}_FLAGS}")
endfunction()

macro(sanitizer_check_target TARGET)
    # Check if this target will be compiled by exactly one compiler. Other-
    # wise sanitizers can't be used and a warning should be printed once.
    get_target_property(TARGET_TYPE ${TARGET} TYPE)
    if(TARGET_TYPE STREQUAL "INTERFACE_LIBRARY")
        message(NOTICE "Can't use any sanitizers for target ${TARGET}, "
                "because it is an interface library and cannot be " "compiled directly.")
        return()
    endif()
    sanitizer_target_compilers(${TARGET} TARGET_COMPILER)
    list(LENGTH TARGET_COMPILER NUM_COMPILERS)
    if(NUM_COMPILERS GREATER 1)
        message(
            NOTICE "Can't use any sanitizers for target ${TARGET}, "
            "because it will be compiled by incompatible compilers. "
            "Target will be compiled without sanitizers.")
        return()

        # If the target is compiled by no or no known compiler, give a warning.
    elseif(NUM_COMPILERS EQUAL 0)
        message(
            NOTICE "Sanitizers for target ${TARGET} may not be"
            " usable, because it uses no or an unknown compiler. "
            "This is a false warning for targets using only " "object lib(s) as input.")
        return()
    endif()
endmacro(sanitizer_check_target)