MSVC: Optimize global data to reduce binary size

Package global data in COMDAT sections for optimization. According to the docs, this can significantly reduce the size of the resulting binary executable. I've tested build Qt with /Gw locally with and without LTCG, the result shows /Gw can reduce the binary size indeed, but not "significantly". The result also reveals that exes can benefit much more from /Gw than dlls. The result can be seen from the QTBUG-98894 bug report. Microsoft Docs: https://docs.microsoft.com/en-us/cpp/build/reference/gw-optimize-global-data?view=msvc-170 Task-number: QTBUG-98894 Change-Id: Ibce34c98e791e519d669a5fe39c0027d1459c382 Reviewed-by: Thiago Macieira <[email protected]> Reviewed-by: Kai Koehne <[email protected]>
sohide · Dec 15, 2021 · d2a0202 · d2a0202
1 parent 877d6cf
commit d2a0202
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/cmake/QtInternalTargets.cmake b/cmake/QtInternalTargets.cmake
@@ -199,7 +199,7 @@ if (MSVC)
     target_compile_options(PlatformCommonInternal INTERFACE -Zc:wchar_t)
 
     target_compile_options(PlatformCommonInternal INTERFACE
-        $<$<NOT:$<CONFIG:Debug>>:-guard:cf>
+        $<$<NOT:$<CONFIG:Debug>>:-guard:cf -Gw>
     )
 
     target_link_options(PlatformCommonInternal INTERFACE