cmake_minimum_required(VERSION "3.27")

project("kernel"
  DESCRIPTION "An educational OS kernel"
  HOMEPAGE_URL "https://gitlab.ost.ch/teachos/kernel"
  VERSION "0.0.1"
  LANGUAGES ASM C CXX
)

#[============================================================================[
# Global Build System Configuration
#]============================================================================]

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/bin")
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}/lib")
set(CMAKE_INTERPROCEDURAL_OPTIMIZATION YES)

set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/Modules")

set(CMAKE_CXX_STANDARD "20")
set(CMAKE_CXX_STANDARD_REQUIRED YES)
set(CMAKE_CXX_EXTENSIONS NO)

#[============================================================================[
# Documentation
#]============================================================================]

find_package("Doxygen")

set(DOXYGEN_GENERATE_HTML YES)
set(DOXYGEN_GENERATE_XML YES)
set(DOXYGEN_EXCLUDE_PATTERNS "*.cpp")
set(DOXYGEN_OUTPUT_DIRECTORY "doxygen")
set(DOXYGEN_QUIET YES)

file(GLOB_RECURSE DOXYGEN_SOURCES CONFIGURE_DEPENDS "*.hpp")

message(STATUS "${SPHINX_SOURCES}")

doxygen_add_docs("docs_xml"
  ${DOXYGEN_SOURCES}
  ALL
  USE_STAMP_FILE
  COMMENT "Generating developer documentation sources"
)

set_target_properties("docs_xml" PROPERTIES
  ADDITIONAL_CLEAN_FILES
  "${PROJECT_BINARY_DIR}/doxygen"
)

file(GLOB_RECURSE SPHINX_SOURCES CONFIGURE_DEPENDS "../docs/**.rst") 

add_custom_target("docs" ALL
  COMMAND "${SPHINX_BUILD_EXE}"
  "../docs"
  "docs"
  "-q"
  DEPENDS "docs_xml"
  SOURCES ${SPHINX_SOURCES}
  COMMENT "Generating developer documentation html"
)

set_target_properties("docs" PROPERTIES
  ADDITIONAL_CLEAN_FILES
  "${PROJECT_BINARY_DIR}/docs"
)

#[============================================================================[
# Global Compiler Configuration
#]============================================================================]

add_compile_options(
  "$<$<CXX_COMPILER_ID:GNU>:-Wall>"
  "$<$<CXX_COMPILER_ID:GNU>:-Wextra>"
  "$<$<CXX_COMPILER_ID:GNU>:-Werror>"
  "$<$<CXX_COMPILER_ID:GNU>:-pedantic-errors>"
  "$<$<CXX_COMPILER_ID:GNU>:-fsanitize=address,leak,bounds,alignment,return,integer-divide-by-zero,vla-bound,null,enum,pointer-overflow>"
)

#[============================================================================[
# Global Directories
#]============================================================================]

include_directories(
  "include"
  "arch/${CMAKE_SYSTEM_PROCESSOR}/include"
)

#[============================================================================[
# The Bootstrap Library
#]============================================================================]

add_library("_boot" OBJECT)
add_library("teachos::boot" ALIAS "_boot")

#[============================================================================[
# The Video Library
#]============================================================================]

add_library("_video" OBJECT)
add_library("teachos::video" ALIAS "_video")

#[============================================================================[
# THE Memory Library
#]============================================================================]

add_library("_memory" OBJECT)
add_library("teachos::memory" ALIAS "_memory")

#[============================================================================[
# The Exception handling Library
#]============================================================================]

add_library("_exception" OBJECT)
add_library("teachos::exception" ALIAS "_exception")

#[============================================================================[
# The Context switching Library
#]============================================================================]

add_library("_context" OBJECT)
add_library("teachos::context_switching" ALIAS "_context")

add_library("_interrupt_handling" OBJECT)
add_library("teachos::interrupt_handling" ALIAS "_interrupt_handling")
# https://forum.osdev.org/viewtopic.php?f=1&t=36712
# https://gcc.gnu.org/onlinedocs/gcc/x86-Function-Attributes.html#index-interrupt-function-attribute_002c-x86
target_compile_options("_interrupt_handling" PRIVATE "-mgeneral-regs-only")

#[============================================================================[
# The Stub Standard Library
#]============================================================================]

add_library("_stl" OBJECT)
add_library("teachos::stl" ALIAS "_stl")

#[============================================================================[
# The Kernel
#]============================================================================]

add_executable("_kernel"
  "src/kernel/main.cpp"
)
add_executable("teachos::kernel" ALIAS "_kernel")

target_link_libraries("_kernel" PRIVATE
  "teachos::boot"
  "teachos::video"
  "teachos::memory"
  "teachos::exception"
  "teachos::stl"
  "teachos::context_switching"
  "teachos::interrupt_handling"
)

#[============================================================================[
# Platform Specific Components
#]============================================================================]

add_subdirectory("arch/${CMAKE_SYSTEM_PROCESSOR}")