# Splits DWARF out of the packaged ELF binaries, then strips them.
#
# This is a CPack pre-build script (CPACK_PRE_BUILD_SCRIPTS, wired in CrashReporting.cmake):
# CPack runs it after staging the install tree and before producing the package, so it only
# ever touches the copy that becomes the release artifact. The build tree is left alone: -g
# stays on, and CI uploads symbols to Sentry straight from build/.
#
# For every ELF file under CPACK_TEMPORARY_DIRECTORY the script extracts the debug information
# to COCKATRICE_DEBUG_SYMBOL_DIR and removes the debug sections from the packaged binary.
# COCKATRICE_DEBUG_SYMBOL_DIR is deliberately outside the staging tree, so sidecars never end
# up in the package; CI can archive/upload them if wanted (it normally uploads straight from
# the build tree). The only thing that must survive stripping is .eh_frame (allocatable, used
# for unwinding), which neither --only-keep-debug nor --strip-debug removes.
#
# Tool paths, the symbol directory and the tree to walk are baked in / provided at configure /
# run time; the guards below refuse to run on anything that is not a CPack staging directory,
# so a missing variable can never turn the glob into a filesystem-wide walk.

set(_objcopy "@COCKATRICE_OBJCOPY@")
set(_strip "@COCKATRICE_STRIP_TOOL@")
set(_symbolDir "@COCKATRICE_DEBUG_SYMBOL_DIR@")

if(_objcopy STREQUAL "" OR _strip STREQUAL "")
  message(WARNING "split debug symbols: objcopy/strip not found at configure time, packaging unstripped binaries")
  return()
endif()
if(_symbolDir STREQUAL "")
  message(FATAL_ERROR "split debug symbols: COCKATRICE_DEBUG_SYMBOL_DIR is empty")
endif()

# CPack sets CPACK_TEMPORARY_DIRECTORY to the staging tree; CMAKE_INSTALL_PREFIX is still the
# configured /usr prefix here, so globbing it would walk system directories. Refuse to run
# unless the path exists and really is a CPack staging tree.
if(NOT CPACK_TEMPORARY_DIRECTORY OR NOT IS_DIRECTORY "${CPACK_TEMPORARY_DIRECTORY}")
  message(STATUS "split debug symbols: no CPack staging directory, skipping")
  return()
endif()
if(NOT CPACK_TEMPORARY_DIRECTORY MATCHES "_CPack_Packages")
  message(WARNING "split debug symbols: ${CPACK_TEMPORARY_DIRECTORY} is not a CPack staging tree, skipping")
  return()
endif()

file(MAKE_DIRECTORY "${_symbolDir}")

file(
  GLOB_RECURSE _entries
  LIST_DIRECTORIES true
  "${CPACK_TEMPORARY_DIRECTORY}/*"
)
set(_processed 0)
foreach(_file IN LISTS _entries)
  if(IS_DIRECTORY "${_file}" OR IS_SYMLINK "${_file}")
    continue()
  endif()
  # Only ELF: objcopy would fail on the icons, translations and Qt resources next to it.
  file(
    READ "${_file}" _magic
    OFFSET 0
    LIMIT 4
    HEX
  )
  if(NOT _magic STREQUAL "7f454c46")
    continue()
  endif()
  get_filename_component(_name "${_file}" NAME)
  set(_debug "${_symbolDir}/${_name}.debug")
  execute_process(COMMAND "${_objcopy}" --only-keep-debug "${_file}" "${_debug}" RESULT_VARIABLE _rc)
  if(NOT _rc EQUAL 0)
    message(WARNING "split debug symbols: objcopy --only-keep-debug failed for ${_file}")
    continue()
  endif()
  execute_process(COMMAND "${_strip}" --strip-debug --strip-unneeded "${_file}" RESULT_VARIABLE _rc)
  if(NOT _rc EQUAL 0)
    message(WARNING "split debug symbols: strip failed for ${_file}")
    continue()
  endif()
  math(EXPR _processed "${_processed} + 1")
endforeach()

message(STATUS "Split debug symbols for ${_processed} packaged ELF file(s); sidecars in ${_symbolDir}")