##
## THIS IS THE MASTER FILE
## It contains some basic defaults and defintions that are inherited by the projects
##

################################################################################
# CONTENTS
#
# Project header
# CMake globals
# Project Settings
# Options

# Targets

# Testing (TODO)
# Packaging (TODO)
################################################################################
cmake_minimum_required(VERSION 3.25 FATAL_ERROR)
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/")
include(ConfigSafeGuards)


################################################################################
#
# Project header
#
#################################################################################

# Suppress "Policy CMP0066 is not set"
# This policy provides compatibility for projects that do not expect
# config-specific compiler flags to be used.
# See https://cmake.org/cmake/help/latest/policy/CMP0066.html
#set (CMAKE_POLICY_WARNING_CMP0066 OFF)




cmake_minimum_required(VERSION 3.10)

# tomsfastmath - modified from CMakeLists.txt created for libtomath
project (TOMSFASTMATH 
    VERSION 0.13.1
    DESCRIPTION "TomsFastMath is meant to be a very fast yet still fairly portable and easy to port large integer arithmetic library written in ISO C."
    HOMEPAGE_URL "https://github.com/libtom/tomsfastmath"
    LANGUAGES C)

# package release version
# bump if re-releasing the same VERSION + patches
# set to 1 if releasing a new VERSION
set(PACKAGE_RELEASE_VERSION 1)
################################################################################
#
# CMake Global Settings
#
################################################################################

# Allow use of function cmake_print_variables to print vars to output
# See https://cmake.org/cmake/help/latest/module/CMakePrintHelpers.html
include(CMakePrintHelpers)


set(CMAKE_EXPORT_COMPILE_COMMANDS ON CACHE INTERNAL "Export compile_commands.json to support editors such as Kate, Visual Studio Code, Vim etc.")

set(CMAKE_VERBOSE_MAKEFILE ON CACHE INTERNAL "Generate verbose makefile")

# For tomsfastmath we use Build, although convention is to use all lowercase
set(CMAKE_BINARY_DIR ${CMAKE_SOURCE_DIR}/Build)


################################################################################
#
# Project Settings
#
#################################################################################

# Define build mode - this must be executed AFTER the project command otherwise
# the cmake compiler will complain that CMAKE_BUILD_TYPE is uninitialised.
message(STATUS "CMAKE_BUILD_TYPE  is ${CMAKE_BUILD_TYPE}")
if (NOT DEFINED CMAKE_BUILD_TYPE OR "${CMAKE_BUILD_TYPE}" STREQUAL "")
    set(CMAKE_BUILD_TYPE RelWithDebInfo CACHE STRING "Choose the type of build...")
endif()

if ( UNIX )
  set(CMAKE_INSTALL_PREFIX /opt/fireswarm  CACHE PATH "Default installation directory" FORCE)
elseif ( WIN32 )
  set(CMAKE_INSTALL_PREFIX $ENV{ProgramFiles}/fireswarm  CACHE PATH "Default installation directory" FORCE)
endif()


################################################################################
#
# Option Settings
#
#################################################################################

# ### Options: Things you can set via commandline options to cmake (e.g. -DTOMSFASTMATH_DISABLE_LIBCXX=[ON|OFF])

option(BUILD_SHARED_LIBS "Build shared library" ON)

option(TOMSFASTMATH_DISABLE_LIBCXX "Do not use libc++, even if available" ON)

option(ENABLE_WARNINGS_SETTINGS "Allow target_set_warnings to add flags and defines.
                                 Set this to OFF if you want to provide your own warning parameters.
                                 See cmake/Warnings.cmake for more info." ON)

option(ENABLE_LTO "Enable link time optimization" ON)


include(LTO)
include(Warnings)
include(functions)
include(sources)
include(CompilerSettings)

# Check for LTO (Link-time optimisation) support.
find_lto(CXX)


include_directories( "src/" "src/headers" )
include(cmake/sources.cmake)

# The only direct cmake argument for now
option(BUILD_SHARED_LIBS "Build shared library and only the shared library if \"ON\", default is static" OFF)

#-----------------------------------------------------------------------------
# Compose CFLAGS
#-----------------------------------------------------------------------------

# Some information ported from makefile_include.mk


if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
  message(STATUS "Setting build type to 'Release' as none was specified.")
  set(CMAKE_BUILD_TYPE "Release")
endif()

# We only differentiate between MSVC and GCC-compatible compilers
if(MSVC)
    set(LTM_C_FLAGS -W3)
elseif(WATCOM)
    set(LTM_C_FLAGS -fo=.obj -oaxt -3r -w3)
else()
    set(LTM_C_FLAGS -Wall -Wsign-compare -Wextra -Wshadow
                    -Wdeclaration-after-statement -Wbad-function-cast -Wcast-align
                    -Wstrict-prototypes -Wpointer-arith -Wsystem-headers)
    set(CMAKE_C_FLAGS_DEBUG "-g3")
    set(CMAKE_C_FLAGS_RELEASE "-O3 -funroll-loops -fomit-frame-pointer")
    set(CMAKE_C_FLAGS_RELWITHDEBINFO "-g3 -O2")
    set(CMAKE_C_FLAGS_MINSIZEREL "-Os")
endif()

# What compiler do we have and what are their...uhm... peculiarities
if(CMAKE_C_COMPILER_ID MATCHES "(C|c?)lang")
    list(APPEND LTM_C_FLAGS -Wno-typedef-redefinition -Wno-tautological-compare -Wno-builtin-requires-header)
    # Clang requires at least '-O1' for dead code elimination
    set(CMAKE_C_FLAGS_DEBUG "-O1 ${CMAKE_C_FLAGS_DEBUG}")
endif()
if(CMAKE_C_COMPILER MATCHES "mingw")
    list(APPEND LTM_C_FLAGS -Wno-shadow -Wno-expansion-to-defined -Wno-declaration-after-statement -Wno-bad-function-cast)
endif()
if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
    list(APPEND LTM_C_FLAGS -Wno-nullability-completeness)
endif()
if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN")
    list(APPEND LTM_C_FLAGS -no-undefined)
endif()

# TODO: coverage (lgcov)

# If the user set the environment variables at generate-time, append them
# in order to allow overriding our defaults.
# ${LTM_CFLAGS} means the user passed it via sth like:
# $ cmake -DLTM_CFLAGS="foo"
list(APPEND LTM_C_FLAGS ${LTM_CFLAGS})
list(APPEND LTM_LD_FLAGS ${LTM_LDFLAGS})

#-----------------------------------------------------------------------------
# library target
#-----------------------------------------------------------------------------
add_library( ${PROJECT_NAME} SHARED
    ${TFM_SOURCE}
    ${TFM_HEADERS}
)

target_include_directories(${PROJECT_NAME} PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}>
)

target_compile_options(${PROJECT_NAME} BEFORE PRIVATE
    ${LTM_C_FLAGS}
)
target_link_options(${PROJECT_NAME} BEFORE PRIVATE
    ${LTM_LD_FLAGS}
)

set(PUBLIC_HEADERS tfm.h)

set_target_properties(${PROJECT_NAME} PROPERTIES
    OUTPUT_NAME tomsfastmath
    VERSION ${PROJECT_VERSION}
    SOVERSION ${PROJECT_VERSION_MAJOR}
    PUBLIC_HEADER "${PUBLIC_HEADERS}"
)

option(COMPILE_LTO "Build with LTO enabled")
if(COMPILE_LTO)
    check_ipo_supported(RESULT COMPILER_SUPPORTS_LTO)
    if(COMPILER_SUPPORTS_LTO)
        set_property(TARGET ${PROJECT_NAME} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
    else()
        message(SEND_ERROR "This compiler does not support LTO. Reconfigure ${PROJECT_NAME} with -DCOMPILE_LTO=OFF.")
    endif()
endif()



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