file(GLOB_RECURSE PROJECT_C_SOURCES
  "${SOURCE_DIR}/src/*.c"
  "${SOURCE_DIR}/src/*.h"
)

foreach(source IN LISTS PROJECT_C_SOURCES)
  file(READ "${source}" contents)
  if(contents MATCHES "(^|[^A-Za-z0-9_])goto([^A-Za-z0-9_]|$)")
    message(FATAL_ERROR "goto is forbidden in project source: ${source}")
  endif()
  if(contents MATCHES "#define[ \t]+static" OR contents MATCHES "#include[ \t]+\"[^\"]+\\.c\"")
    message(FATAL_ERROR "test-only source visibility hack found: ${source}")
  endif()
  string(FIND "${source}" "/src/sys/" sys_position)
  if(sys_position EQUAL -1 AND
     contents MATCHES "windows\\.h|GetFullPathNameW|CreateFileW|ReadFile|WriteFile|MoveFileExW|BCryptGenRandom")
    message(FATAL_ERROR "OS-specific API reference outside src/sys: ${source}")
  endif()
endforeach()

if(NOT CLANG_FORMAT_EXECUTABLE STREQUAL "")
  execute_process(
    COMMAND "${CLANG_FORMAT_EXECUTABLE}" --dry-run --Werror ${PROJECT_C_SOURCES}
    RESULT_VARIABLE format_result
    OUTPUT_VARIABLE format_output
    ERROR_VARIABLE format_error
  )
  if(NOT format_result EQUAL 0)
    message(FATAL_ERROR "clang-format check failed:\n${format_output}${format_error}")
  endif()
endif()

execute_process(
  COMMAND "${GIT_EXECUTABLE}" diff --check
  WORKING_DIRECTORY "${SOURCE_DIR}"
  RESULT_VARIABLE diff_result
  OUTPUT_VARIABLE diff_output
  ERROR_VARIABLE diff_error
)
if(NOT diff_result EQUAL 0)
  message(FATAL_ERROR "git diff --check failed:\n${diff_output}${diff_error}")
endif()