4 files changed, 35 insertions, 0 deletions
diff --git a/sources/pyside6/cmake/Macros/PySideModules.cmake b/sources/pyside6/cmake/Macros/PySideModules.cmake
index c5bee643c..d722b4650 100644
--- a/sources/pyside6/cmake/Macros/PySideModules.cmake
+++ b/sources/pyside6/cmake/Macros/PySideModules.cmake
@@ -18,6 +18,19 @@ macro(unmake_path varname)
    string(REPLACE "${PATH_SEP}" ";" ${varname} "${ARGN}")
 endmacro()
 
+# set size optimization flags for pyside6
+macro(append_size_optimization_flags _module_name)
+    if(NOT QFP_NO_OVERRIDE_OPTIMIZATION_FLAGS)
+        if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+            target_compile_options(${_module_name} PRIVATE /Gy /Gw /EHsc)
+            target_link_options(${_module_name} PRIVATE LINKER:/OPT:REF)
+        elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU|CLANG")
+            target_compile_options(${_module_name} PRIVATE -ffunction-sections -fdata-sections -fno-exceptions)
+            target_link_options(${_module_name} PRIVATE LINKER:--gc-sections)
+        endif()
+    endif()
+endmacro()
+
 # Sample usage
 # create_pyside_module(NAME QtGui
 #                      INCLUDE_DIRS QtGui_include_dirs
@@ -146,6 +159,9 @@ macro(create_pyside_module)
     include_directories(${module_NAME} ${${module_INCLUDE_DIRS}} ${pyside6_SOURCE_DIR})
     add_library(${module_NAME} MODULE ${${module_SOURCES}}
                                       ${${module_STATIC_SOURCES}})
+
+    append_size_optimization_flags(${module_NAME})
+
     set_target_properties(${module_NAME} PROPERTIES
                           PREFIX ""
                           OUTPUT_NAME "${module_NAME}${SHIBOKEN_PYTHON_EXTENSION_SUFFIX}"
diff --git a/sources/pyside6/cmake/PySideHelpers.cmake b/sources/pyside6/cmake/PySideHelpers.cmake
index 86cda83f8..0de8e1bdc 100644
--- a/sources/pyside6/cmake/PySideHelpers.cmake
+++ b/sources/pyside6/cmake/PySideHelpers.cmake
@@ -252,3 +252,16 @@ macro(collect_module_if_found shortname)
         endif()
     endif()
 endmacro()
+
+# resets the RELEASE CXX flags for size based optimization
+macro(override_release_flags_for_size_optimization)
+    if(NOT QFP_NO_OVERRIDE_OPTIMIZATION_FLAGS)
+        if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+            set(CMAKE_CXX_FLAGS_RELEASE "/O1 /DNDEBUG")
+        elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+            set(CMAKE_CXX_FLAGS_RELEASE "-Os -DNDEBUG")
+        elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+            set(CMAKE_CXX_FLAGS_RELEASE "-Oz -DNDEBUG")
+        endif()
+    endif()
+endmacro()
diff --git a/sources/pyside6/cmake/PySideSetup.cmake b/sources/pyside6/cmake/PySideSetup.cmake
index 08072ac02..a167f4ddd 100644
--- a/sources/pyside6/cmake/PySideSetup.cmake
+++ b/sources/pyside6/cmake/PySideSetup.cmake
@@ -12,6 +12,9 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/Macros")
 include(ShibokenHelpers)
 include(PySideHelpers)
 
+#does nothing if QFP_NO_OVERRIDE_OPTIMIZATION_FLAGS (no-size-optimization) flag is not set
+override_release_flags_for_size_optimization()
+
 # Don't display "up-to-date / install" messages when installing, to reduce visual clutter.
 if(QUIET_BUILD)
     set(CMAKE_INSTALL_MESSAGE NEVER)
diff --git a/sources/pyside6/libpyside/CMakeLists.txt b/sources/pyside6/libpyside/CMakeLists.txt
index cd39483a3..0b2f7a097 100644
--- a/sources/pyside6/libpyside/CMakeLists.txt
+++ b/sources/pyside6/libpyside/CMakeLists.txt
@@ -50,6 +50,9 @@ add_other_files(${other_files})
 add_library(pyside6 SHARED ${libpyside_SRC} ${other_files})
 add_library(PySide6::pyside6 ALIAS pyside6)
 
+#does nothing if QFP_NO_OVERRIDE_OPTIMIZATION_FLAGS (no-size-optimization) flag is not set
+append_size_optimization_flags(pyside6)
+
 target_include_directories(pyside6 PUBLIC
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
   $<INSTALL_INTERFACE:include/PySide6>