qt5base-lts/cmake/QtScopeFinalizerHelpers.cmake
Alexandru Croitor 69d9b2b6fd CMake: Use cmake_language(DEFER) when available for scope finalizers
If CMake version is 3.19 or greater, use cmake_language(DEFER CALL)
for Qt internal scope finalizers, instead of the homegrown
implementation.

Apart from not depending on the hacky homegrown solution, it
significantly improves the readability of --trace-redirect logs.

Pick-to: 6.0
Task-number: QTBUG-77377
Change-Id: I5ce374bb313865662c536826e86052bc762438b9
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
2020-11-25 22:08:10 +01:00

99 lines
4.2 KiB
CMake

# Add a finalizer function for the current CMake list file.
# It will be processed just before leaving the current source directory scope.
#
# When using CMake 3.18 or lower:
# You may add up to nine arguments that are passed to the finalizer.
# A finalizer that is registered with qt_add_list_file_finalizer(foo bar baz)
# will be called with nine arguments: foo(bar baz IGNORE IGNORE IGNORE...),
# because CMake's handling of empty list elements is a cruel joke.
# For CMake < 3.18 the function qt_watch_current_list_dir must know about the finalizer.
#
# When using CMake 3.19 or higher, no more INGORE parameters are passed. Instead we
# use cmake_language(DEFER CALL) and pass arguments as usual.
# qt_watch_current_list_dir also doesn't need to know about the finalizer
function(qt_add_list_file_finalizer func)
set(use_cmake_defer_call TRUE)
if(CMAKE_VERSION VERSION_LESS "3.19.0")
set(use_cmake_defer_call FALSE)
endif()
if(use_cmake_defer_call)
cmake_language(EVAL CODE "cmake_language(DEFER CALL \"${func}\" ${ARGN}) ")
else()
set_property(GLOBAL APPEND
PROPERTY QT_LIST_FILE_FINALIZER_FILES "${CMAKE_CURRENT_LIST_FILE}")
set_property(GLOBAL APPEND
PROPERTY QT_LIST_FILE_FINALIZER_FUNCS ${func})
foreach(i RANGE 1 9)
set(arg "${ARGV${i}}")
if(i GREATER_EQUAL ARGC OR "${arg}" STREQUAL "")
set(arg "IGNORE")
endif()
set_property(GLOBAL APPEND
PROPERTY QT_LIST_FILE_FINALIZER_ARGV${i} "${arg}")
endforeach()
endif()
endfunction()
# Watcher function for the variable CMAKE_CURRENT_LIST_DIR.
# This is the driver of the finalizer facility.
function(qt_watch_current_list_dir variable access value current_list_file stack)
if(NOT access STREQUAL "MODIFIED_ACCESS")
# We are only interested in modifications of CMAKE_CURRENT_LIST_DIR.
return()
endif()
list(GET stack -1 stack_top)
if(stack_top STREQUAL current_list_file)
# If the top of the stack equals the current list file then
# we're entering a file. We're not interested in this case.
return()
endif()
get_property(files GLOBAL PROPERTY QT_LIST_FILE_FINALIZER_FILES)
if(NOT files)
return()
endif()
get_property(funcs GLOBAL PROPERTY QT_LIST_FILE_FINALIZER_FUNCS)
foreach(i RANGE 1 9)
get_property(args${i} GLOBAL PROPERTY QT_LIST_FILE_FINALIZER_ARGV${i})
endforeach()
list(LENGTH files n)
set(i 0)
while(i LESS n)
list(GET files ${i} file)
if(file STREQUAL stack_top)
list(GET funcs ${i} func)
foreach(k RANGE 1 9)
list(GET args${k} ${i} a${k})
endforeach()
# We've found a file we're looking for. Call the finalizer.
if(${CMAKE_VERSION} VERSION_LESS "3.18.0")
# Make finalizer known functions here:
if(func STREQUAL "qt_finalize_module")
qt_finalize_module(${a1} ${a2} ${a3} ${a4} ${a5} ${a6} ${a7} ${a8} ${a9})
elseif(func STREQUAL "qt_finalize_plugin")
qt_finalize_plugin(${a1} ${a2} ${a3} ${a4} ${a5} ${a6} ${a7} ${a8} ${a9})
elseif(func STREQUAL "qt_internal_finalize_app")
qt_internal_finalize_app(${a1} ${a2} ${a3} ${a4} ${a5} ${a6} ${a7} ${a8} ${a9})
else()
message(FATAL_ERROR "qt_watch_current_list_dir doesn't know about ${func}. Consider adding it.")
endif()
else()
cmake_language(CALL ${func} ${a1} ${a2} ${a3} ${a4} ${a5} ${a6} ${a7} ${a8} ${a9})
endif()
list(REMOVE_AT files ${i})
list(REMOVE_AT funcs ${i})
foreach(k RANGE 1 9)
list(REMOVE_AT args${k} ${i})
endforeach()
math(EXPR n "${n} - 1")
else()
math(EXPR i "${i} + 1")
endif()
endwhile()
set_property(GLOBAL PROPERTY QT_LIST_FILE_FINALIZER_FILES ${files})
set_property(GLOBAL PROPERTY QT_LIST_FILE_FINALIZER_FUNCS ${funcs})
foreach(i RANGE 1 9)
set_property(GLOBAL PROPERTY QT_LIST_FILE_FINALIZER_ARGV${i} "${args${i}}")
endforeach()
endfunction()