cmake_minimum_required(VERSION 3.16)
project(duckstation C CXX)

# Policy settings.
cmake_policy(SET CMP0069 NEW)
set(CMAKE_POLICY_DEFAULT_CMP0069 NEW)

if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR})
  message(FATAL_ERROR "DuckStation does not support in-tree builds. Please make a build directory that is not the source"
                      "directory and generate your CMake project there using either `cmake -B build_directory` or by "
                      "running cmake from the build directory.")
endif()

if(NOT CMAKE_BUILD_TYPE MATCHES "Debug|Devel|MinSizeRel|RelWithDebInfo|Release")
  message(STATUS "CMAKE_BUILD_TYPE not set, defaulting to Release.")
  set(CMAKE_BUILD_TYPE "Release")
endif()

message(STATUS "CMake Version: ${CMAKE_VERSION}")
message(STATUS "CMake System Name: ${CMAKE_SYSTEM_NAME}")
message(STATUS "Build Type: ${CMAKE_BUILD_TYPE}")

# Pull in modules.
set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/CMakeModules/")
include(DuckStationUtils)

# Detect system attributes.
detect_operating_system()
detect_compiler()
detect_architecture()
detect_page_size()
detect_cache_line_size()

# Build options. Depends on system attributes.
include(DuckStationBuildOptions)
include(DuckStationDependencies)

# Enable PIC on Linux, otherwise the builds do not support ASLR.
if(LINUX OR BSD)
  include(CheckPIESupported)
  check_pie_supported()
  set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
endif()

# Release build optimizations for MSVC.
if(MSVC)
  add_definitions("/D_CRT_SECURE_NO_WARNINGS")
  foreach(config CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
    # Set warning level 3 instead of 4.
    string(REPLACE "/W3" "/W4" ${config} "${${config}}")

    # Enable intrinsic functions, disable minimal rebuild, UTF-8 source, set __cplusplus version.
    set(${config} "${${config}} /Oi /Gm- /utf-8 /Zc:__cplusplus")
  endforeach()

  # RelWithDebInfo is set to Ob1 instead of Ob2.   
  string(REPLACE "/Ob1" "/Ob2" CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}")
  string(REPLACE "/Ob1" "/Ob2" CMAKE_C_FLAGS_DEVEL "${CMAKE_C_FLAGS_DEVEL}")
  string(REPLACE "/Ob1" "/Ob2" CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
  string(REPLACE "/Ob1" "/Ob2" CMAKE_CXX_FLAGS_DEVEL "${CMAKE_CXX_FLAGS_DEVEL}")

  # Disable incremental linking in RelWithDebInfo.
  string(REPLACE "/INCREMENTAL" "/INCREMENTAL:NO" CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO}")
  string(REPLACE "/INCREMENTAL" "/INCREMENTAL:NO" CMAKE_EXE_LINKER_FLAGS_DEVEL "${CMAKE_EXE_LINKER_FLAGS_DEVEL}")

  # COMDAT folding/remove unused functions.
  set(CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} /OPT:REF /OPT:ICF")
  set(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO} /OPT:REF /OPT:ICF")
  set(CMAKE_EXE_LINKER_FLAGS_DEVEL "${CMAKE_EXE_LINKER_FLAGS_DEVEL} /OPT:REF /OPT:ICF")
endif()

# Warning disables.
if(COMPILER_CLANG OR COMPILER_CLANG_CL OR COMPILER_GCC)
  include(CheckCXXFlag)
  check_cxx_flag(-Wall COMPILER_SUPPORTS_WALL)
  check_cxx_flag(-Wno-class-memaccess COMPILER_SUPPORTS_MEMACCESS)
  check_cxx_flag(-Wno-invalid-offsetof COMPILER_SUPPORTS_OFFSETOF)
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-switch")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-switch")
endif()

# We don't need exceptions, disable them to save a bit of code size.
if(MSVC)
  string(REPLACE "/EHsc" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
  string(REPLACE "/GR" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")

  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /D_HAS_EXCEPTIONS=0 /permissive-")
  if(COMPILER_CLANG_CL)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /clang:-fno-rtti")
  endif()
else()
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-exceptions -fno-rtti")
endif()

# Write binaries to a seperate directory.
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin")

# Installation directories. If INSTALL_SELF_CONTAINED is set, everything goes
# into one directory, otherwise CMAKE_INSTALL_PREFIX/bin is used (for Flatpak).
if(ALLOW_INSTALL)
  if(INSTALL_SELF_CONTAINED)
    set(CMAKE_INSTALL_BINDIR "${CMAKE_INSTALL_PREFIX}")
    set(CMAKE_INSTALL_LIBDIR "${CMAKE_INSTALL_PREFIX}")
  else()
    # Let GNUInstallDirs set the destinations.
    include(GNUInstallDirs)
  endif()
endif()

# Enable large file support on Linux 32-bit platforms.
if(CMAKE_SIZEOF_VOID_P EQUAL 4)
  add_definitions("-D_FILE_OFFSET_BITS=64")
endif()

# Optional unit tests.
if(BUILD_TESTS)
  enable_testing()
endif()

# Prevent fmt from being built with exceptions, or being thrown at call sites.
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DFMT_EXCEPTIONS=0")

# Use C++20.
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Recursively include the source tree.
add_subdirectory(dep)
add_subdirectory(src)

# Output build summary.
include(DuckStationBuildSummary)