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# Shared CMake logic for every platform that builds the Nim library from
# source. Included by android/, linux/ and windows/.
cmake_minimum_required(VERSION 3.15)
project(nimflutter LANGUAGES C)

find_program(NIM_EXECUTABLE nim REQUIRED
  DOC "The Nim compiler. Set -DNIM_EXECUTABLE=/path/to/nim to override.")

set(NF_SRC "${CMAKE_CURRENT_LIST_DIR}/nimflutter.nim")

# Nim cross-compiles by emitting C, so the reliable pattern is:
#   Nim source -> C  (Nim's job)     C -> object/library  (the toolchain's)
# This keeps the NDK / MSVC / clang in charge of ABI, sysroot and flags.
#
# Nim writes one .c per module rather than a single file, and the set is only
# known after it runs — so it runs at CONFIGURE time and the results are
# globbed, instead of the add_custom_command a single-file emitter allows.
set(NF_NIMCACHE "${CMAKE_CURRENT_BINARY_DIR}/nimcache")

execute_process(
  COMMAND "${NIM_EXECUTABLE}" c --compileOnly --nimcache:${NF_NIMCACHE}
          --mm:arc -d:danger --threads:on --noMain "${NF_SRC}"
  RESULT_VARIABLE NF_NIM_RESULT
  OUTPUT_VARIABLE NF_NIM_OUTPUT
  ERROR_VARIABLE NF_NIM_OUTPUT)
if(NOT NF_NIM_RESULT EQUAL 0)
  message(FATAL_ERROR "nim failed to emit C:\n${NF_NIM_OUTPUT}")
endif()

file(GLOB NF_GENERATED_C "${NF_NIMCACHE}/*.c")
if(NF_GENERATED_C STREQUAL "")
  message(FATAL_ERROR "nim produced no C in ${NF_NIMCACHE}")
endif()

add_library(nimflutter SHARED ${NF_GENERATED_C})

# nimbase.h lives in Nim's own lib/, alongside the compiler.
get_filename_component(NF_NIM_BIN "${NIM_EXECUTABLE}" DIRECTORY)
get_filename_component(NF_NIM_ROOT "${NF_NIM_BIN}" DIRECTORY)

target_include_directories(nimflutter PUBLIC
  "${CMAKE_CURRENT_LIST_DIR}"
  "${NF_NIM_ROOT}/lib")

# Nim's generated C is machine output: silence the noise, keep real errors.
#
# -O2 is set unconditionally, including in Debug. This library is a numeric
# kernel with no Dart-visible debugger story of its own, and at -O0 the
# Mandelbrot path runs several times slower than the equivalent Dart — which
# makes a debug run of the example wildly misrepresent the bridge.
if(MSVC)
  target_compile_options(nimflutter PRIVATE /O2)
else()
  target_compile_options(nimflutter PRIVATE
    -O2 -w -fPIC -Wno-int-conversion -Wno-incompatible-pointer-types)
endif()

if(ANDROID)
  target_link_libraries(nimflutter PRIVATE log)
endif()

# Nim's threading support needs pthreads where the platform has them.
find_package(Threads)
if(Threads_FOUND AND NOT ANDROID AND NOT WIN32)
  target_link_libraries(nimflutter PRIVATE Threads::Threads)
endif()

set_target_properties(nimflutter PROPERTIES
  OUTPUT_NAME "nimflutter"
  C_VISIBILITY_PRESET hidden)