# Cross-compile for Windows x86_64 with llvm-mingw: clang + libc++ + the
# libc++ `std` module, targeting the MSVCRT MinGW runtime (which is what the
# official SDL3 MinGW package links against).

# The `import std` gate must be set before the compiler is probed; a toolchain
# file is processed earlier than the project's own top-level settings.
set(CMAKE_EXPERIMENTAL_CXX_IMPORT_STD "d0edc3af-4c50-42ea-a356-e2862fe7a444")

set(CMAKE_SYSTEM_NAME Windows)
set(CMAKE_SYSTEM_PROCESSOR x86_64)

set(OPENRA3_LLVM_MINGW_ROOT "/opt/llvm-mingw" CACHE PATH "llvm-mingw installation root")
if(NOT EXISTS "${OPENRA3_LLVM_MINGW_ROOT}/bin/clang++")
    message(FATAL_ERROR "llvm-mingw not found at ${OPENRA3_LLVM_MINGW_ROOT} (expected bin/clang++)")
endif()

set(CMAKE_C_COMPILER "${OPENRA3_LLVM_MINGW_ROOT}/bin/clang")
set(CMAKE_CXX_COMPILER "${OPENRA3_LLVM_MINGW_ROOT}/bin/clang++")
set(CMAKE_C_COMPILER_TARGET x86_64-w64-mingw32)
set(CMAKE_CXX_COMPILER_TARGET x86_64-w64-mingw32)
# CMake's standard-library detection does not pass COMPILER_TARGET, so without
# this it probes the host standard library. Putting the target in ARG1 makes
# the probe see libc++ (the MinGW target's library).
set(CMAKE_C_COMPILER_ARG1 "--target=x86_64-w64-mingw32")
set(CMAKE_CXX_COMPILER_ARG1 "--target=x86_64-w64-mingw32")

# libc++ standard-library module description for the MinGW target. Must be set
# before the compiler is probed so CMake can build `import std;`.
set(CMAKE_CXX_STDLIB_MODULES_JSON "${OPENRA3_LLVM_MINGW_ROOT}/x86_64-w64-mingw32/lib/libc++.modules.json")

# Select libc++ explicitly so CMake's `import std` detection recognises the
# standard library (llvm-mingw defaults to it, but CMake keys off -stdlib=).
set(CMAKE_CXX_FLAGS_INIT "-stdlib=libc++")
set(CMAKE_EXE_LINKER_FLAGS_INIT "-stdlib=libc++")
set(CMAKE_SHARED_LINKER_FLAGS_INIT "-stdlib=libc++")

# Official SDL3 MinGW development package (headers + import library + DLL).
set(OPENRA3_SDL3_ROOT "/opt/sdl3-mingw" CACHE PATH "SDL3 MinGW development package root")
# The triple-named subdirectory inside the SDL3 MinGW package.
set(OPENRA3_SDL3_MINGW_TRIPLE "x86_64-w64-mingw32" CACHE STRING "SDL3 MinGW triple subdirectory")

set(CMAKE_FIND_ROOT_PATH "${OPENRA3_LLVM_MINGW_ROOT}/x86_64-w64-mingw32")
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)