cmake_minimum_required(VERSION 3.20)
message(STATUS "CMake version: ${CMAKE_VERSION}")

project(fortuna LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

OPTION(TIDY "Run clang-tidy" OFF)
OPTION(VALGRIND "Run valgrind" OFF)
OPTION(SAN "Build with sanitize flags" OFF)
if(DEFINED ENV{CI})
  if($ENV{CI} MATCHES "true")
    message(STATUS "We're in CI!")
    OPTION(IS_CI "Are we in CI?" ON)
  endif()
else()
  OPTION(IS_CI "Are we in CI?" OFF)
endif()

find_package(Git QUIET)
if(GIT_FOUND AND EXISTS "${PROJECT_SOURCE_DIR}/.git")
  if(IS_CI)
    # there seems to be a race condition so the submodules are simply
    # initialized/updated in a separate step and therefore this is not needed
    option(GIT_SUBMODULE "Check submodules during build" OFF)
  else()
    option(GIT_SUBMODULE "Check submodules during build" ON)
  endif()
  if(GIT_SUBMODULE)
    message(STATUS "Update submodule(s)")
    message(STATUS "Current source dir: ${CMAKE_CURRENT_SOURCE_DIR}")
    execute_process(COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive
                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
                    RESULT_VARIABLE GIT_SUBMOD_RESULT)
    if(NOT GIT_SUBMOD_RESULT EQUAL "0")
      message(FATAL_ERROR "git submodule update --init --recursive failed with ${GIT_SUBMOD_RESULT}, please checkout submodules")
    endif()
  endif()
endif()

add_subdirectory(lib/fmt EXCLUDE_FROM_ALL)
add_subdirectory(lib/fmtlog EXCLUDE_FROM_ALL)
add_subdirectory(lib/da_threading EXCLUDE_FROM_ALL)

if(NOT CMAKE_CXX_FLAGS MATCHES "-Wall")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
endif(NOT CMAKE_CXX_FLAGS MATCHES "-Wall")

if(CMAKE_BUILD_TYPE MATCHES "Debug")

  if(TIDY)
    message(STATUS "TIDY=ON, running clang-tidy")
    set(CMAKE_CXX_CLANG_TIDY clang-tidy -p ${CMAKE_CURRENT_BINARY_DIR} --checks=-*,clang-diagnostic-*,clang-analyzer-*,google-*,bugprone-* --header-filter= --use-color=true)
    message(STATUS "CMAKE_CXX_CLANG_TIDY: ${CMAKE_CXX_CLANG_TIDY}")
  endif()


  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -grecord-gcc-switches")
  endif()

  # Produce debugging information in the operating system's native format.
  # Level 3 includes extra information, such as all the macro definitions
  # present in the program. Some debuggers support macro expansion when you
  # use -g3
  if(NOT CMAKE_CXX_FLAGS MATCHES "-g")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g3")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-g")

  # Optimize debugging experience. -Og should be the optimization level of
  # choice for the standard edit-compile-debug cycle, offering a reasonable
  # level of optimization while maintaining fast compilation and a good
  # debugging experience. It is a better choice than -O0 for producing
  # debuggable code because some compiler passes that collect debug
  # information are disabled at -O0.
  if(NOT CMAKE_CXX_FLAGS MATCHES "-Og")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Og")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-Og")

  if(NOT VALGRIND)
    if(SAN)
      message(STATUS "SAN=ON, building with sanitize flags")
      # this needs {libasan,liblsan,libubsan} on fedora, gcc-libs on arch
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=leak") # issue with gdb
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=pointer-compare")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=pointer-subtract")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=vla-bound")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize-address-use-after-scope")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-clash-protection")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=undefined")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=bounds")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=vptr")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=pointer-overflow")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=enum")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=signed-integer-overflow")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=null")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=return")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=integer-divide-by-zero")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=float-cast-overflow")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=unreachable")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=alignment")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=object-size")
      if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
        if(NOT CMAKE_CXX_FLAGS MATCHES "-fsanitize=address" OR "-fsanitize=leak")
          # clang-only atm
          # also doesn't like asan, leaksan et al.
          set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=safe-stack")
        endif()
      endif()
    endif(SAN)


    # If DWARF debugging information is enabled, separate as much debugging
    # information as possible into a separate output file with the extension
    # .dwo. This option allows the build system to avoid linking files with
    # debug information.
    if(NOT CMAKE_CXX_FLAGS MATCHES "-gsplit-dwarf")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -gsplit-dwarf")
    endif(NOT CMAKE_CXX_FLAGS MATCHES "-gsplit-dwarf")
  else()
    message(STATUS "VALGRIND=ON, not setting '-gsplit-dwarf'")
  endif(NOT VALGRIND)

  if(NOT CMAKE_CXX_FLAGS MATCHES "-Wextra")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wextra")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-Wextra")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-Wpedantic")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wpedantic")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-Wpedantic")

endif(CMAKE_BUILD_TYPE MATCHES "Debug")

if(CMAKE_BUILD_TYPE MATCHES "Release")

  # Optimize yet more.
  if(NOT CMAKE_CXX_FLAGS MATCHES "-O3")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O3")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-O3")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-DNDEBUG")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNDEBUG")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-DNDEBUG")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-fstack-protector-all")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstack-protector-all")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-fstack-protector-all")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-fdelete-null-pointer-checks")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdelete-null-pointer-checks")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-fdelete-null-pointer-checks")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-fisolate-erroneous-paths-dereference")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fisolate-erroneous-paths-dereference")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-fisolate-erroneous-paths-dereference")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-ftree-loop-if-convert")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ftree-loop-if-convert")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-ftree-loop-if-convert")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-funwind-tables")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -funwind-tables")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-funwind-tables")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-fasynchronous-unwind-tables")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fasynchronous-unwind-tables")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-fasynchronous-unwind-tables")

  if(NOT CMAKE_CXX_FLAGS MATCHES "-Wp,-D_FORTIFY_SOURCE=2")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wp,-D_FORTIFY_SOURCE=2")
  endif(NOT CMAKE_CXX_FLAGS MATCHES "-Wp,-D_FORTIFY_SOURCE=2")
endif(CMAKE_BUILD_TYPE MATCHES "Release")

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsplit-stack")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wformat -Wformat-security")

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native -mtune=generic -pipe -fno-plt")
if(NOT CMAKE_CXX_FLAGS MATCHES "-fPIC")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")
endif(NOT CMAKE_CXX_FLAGS MATCHES "-fPIC")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIE")
# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fcf-protection")
add_compile_options (-fdiagnostics-show-location=once)

if(CMAKE_BUILD_TYPE MATCHES "Debug")
  set(LDFLAGS "${LDFLAGS} -Wl,-Og,–sort-common,–as-needed,-z,now,-pic,-pie")
elseif(CMAKE_BUILD_TYPE MATCHES "Release")
  set(LDFLAGS "${LDFLAGS} -Wl,-O1,–sort-common,–as-needed,-z,relro,-z,now,-pic,-pie,-flto")
endif()

# inspired by https://medium.com/@alasher/colored-c-compiler-output-with-ninja-clang-gcc-10bfe7f2b949
option (COLORS_FOREVER "Always produce ANSI-colored output (GNU/Clang only)." TRUE)
if (${COLORS_FOREVER})
    message(STATUS "COLORS_FOREVER: ${COLORS_FOREVER}")
  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
    add_compile_options (-fdiagnostics-color=always)
  elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
    add_compile_options (-fcolor-diagnostics)
  endif ()
endif ()

message(STATUS "Compiler ID: ${CMAKE_CXX_COMPILER_ID}")
message(STATUS "CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS}")
message(STATUS "LDFLAGS: ${LDFLAGS}")

find_program(LLD lld)
if(LLD)
  if(NOT CMAKE_EXE_LINKER_FLAGS MATCHES "-fuse-ld=lld")
    message(STATUS "Linker: lld: ${LLD}")
    set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=lld")
  endif(NOT CMAKE_EXE_LINKER_FLAGS MATCHES "-fuse-ld=lld")
endif()
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_CXX_FLAGS}")


set(FORTUNA_SOURCES
  main.cpp
  fortuna.cpp
  generator.cpp
  accumulator.cpp
  pool.cpp
  do_task.cpp
  seed_file_management.cpp)
set(FORTUNA_HEADERS
  fortuna.h
  generator.h
  accumulator.h
  pool.h
  do_task.h
  event_adder.h
  event_adder_impl.h
  event_scheduler.h
  entropy_src.h
  urandom_entropy_src.h
  util.h
  seed_file_management.h)
add_executable(fortuna ${FORTUNA_SOURCES} ${FORTUNA_HEADERS})
target_include_directories(fortuna PRIVATE .)
target_compile_features(fortuna PUBLIC cxx_std_20)

if(CMAKE_BUILD_TYPE MATCHES "Debug")
  message(STATUS "Looking for iwyu...")
  find_program(iwyu NAMES include-what-you-use iwyu)
  if(iwyu)
      message(STATUS "iwyu found at: ${iwyu}")
    set(iwyu_and_options
      ${iwyu}
      -Xiwyu
      -p .
      --verbose=3)
    set_property(TARGET fortuna PROPERTY CXX_INCLUDE_WHAT_YOU_USE ${iwyu_and_options})
  else()
    message(STATUS "iwyu, not found")
  endif()
endif()

# add_executable(fortuna main.cpp generator.cpp generator.h fortuna.cpp fortuna.h accumulator.cpp accumulator.h pool.cpp pool.h event_adder.h event_adder_impl.h event_scheduler.h entropy_src.h urandom_entropy_src.h do_task.cpp do_task.h util.h seed_file_management.cpp seed_file_management.h)
# ref: https://cmake.org/pipermail/cmake/2016-May/063400.html
target_link_libraries(fortuna
  PRIVATE cryptopp
  fmt::fmt
  PRIVATE fmtlog::fmtlog
  PRIVATE da_threading::da_threading
  PRIVATE pthread)

# vim: ft=cmake ff=unix softtabstop=2