Merged PR 2475924: compiler switches to reduce binary size.

trying out a few compiler optimization switches to reduce binary size. (thanks to some tips from https://ptspts.blogspot.com/2013/12/how-to-make-smaller-c-and-c-binaries.html)
On MacOs/ios, got gains of ~200K. Not much on android for some reason, could be that the android toolchain is interfering somehow.

Related work items: #19337401

cmake/crypto.cmake

@@ -9,8 +9,9 @@ set( TARGET_INCLUDE_DIRS ${OpenSLL_INCLUDE_PATH} )
 set( TARGET_INCLUDE_DIRS_PRIVATE "${TARGET_SOURCE_DIR_TRUE}" "${TARGET_SOURCE_DIR_TRUE}/asn1" "${TARGET_SOURCE_DIR_TRUE}/evp" "${TARGET_SOURCE_DIR_TRUE}/modes")
 set( TARGET_DEFINES "OPENSSL_THREADS" )
 set( TARGET_DEFINES_PRIVATE "${OpenSSL_COMPILER_DEFINES}" )
-set( TARGET_COMPILE_FLAGS "" )
-set( TARGET_COMPILE_FLAGS_PRIVATE "" )
+set( TARGET_COMPILE_FLAGS -fno-rtti -fno-stack-protector -O1 -fno-unwind-tables -fno-asynchronous-unwind-tables
+    -fno-math-errno -fno-unroll-loops -fmerge-all-constants)
+set( TARGET_COMPILE_FLAGS_PRIVATE -ffunction-sections -fdata-sections)
 set( TARGET_LINK "" )
 set( TARGET_LINK_PRIVATE "" )
 set( TARGET_SOURCES "" )
@@ -94,9 +95,7 @@ add_library(crypto STATIC ${TARGET_SOURCES})
 
 target_include_directories( crypto PRIVATE ${TARGET_INCLUDE_DIRS} ${TARGET_INCLUDE_DIRS_PRIVATE} )
 target_compile_definitions( crypto PRIVATE ${TARGET_DEFINES} ${TARGET_DEFINES_PRIVATE} )
-target_link_libraries     ( crypto PRIVATE ${TARGET_LINK} ${TARGET_LINK_PRIVATE} )
-target_compile_options    ( crypto PRIVATE ${TARGET_COMPILE_FLAGS} ${TARGET_COMPILE_FLAGS_PRIVATE} )
+target_compile_options    ( crypto PRIVATE ${TARGET_COMPILE_FLAGS} ${TARGET_COMPILE_FLAGS_PRIVATE})
 target_include_directories( crypto PUBLIC  ${TARGET_INCLUDE_DIRS} ${OpenSLL_INCLUDE_PATH} ${OpenSLL_INCLUDE_PATH}/openssl)
 target_compile_definitions( crypto PUBLIC  ${TARGET_DEFINES} )
-target_link_libraries     ( crypto PUBLIC  ${TARGET_LINK} )
-target_compile_options    ( crypto PUBLIC  ${TARGET_COMPILE_FLAGS} )
+target_compile_options    ( crypto PUBLIC  ${TARGET_COMPILE_FLAGS})

src/msix/CMakeLists.txt

@@ -239,8 +239,9 @@ target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_PROJECT_ROOT}/src/inc
 
 
 if(WIN32)
+    string(REPLACE "/GR" " " CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
     set_target_properties(${PROJECT_NAME} PROPERTIES
-        COMPILE_FLAGS "/source-charset:utf-8"
+        COMPILE_FLAGS "/source-charset:utf-8 /Gw /GL /GR-"
         VS_WINRT_COMPONENT TRUE)
     # Using /DELAYLOAD as linker option will use a helper funtion provided by
     # Visual C++ that will load the dll at runtime by calling LoadLibrary and GetProcAddress.
@@ -252,7 +253,7 @@ if(WIN32)
             "/DELAYLOAD:api-ms-win-core-winrt-string-l1-1-0.dll"
             "/DELAYLOAD:api-ms-win-core-winrt-l1-1-0.dll")
     string(REPLACE ";" " " DELAYFLAGS "${DELAYFLAGS}")
-    set_property(TARGET ${PROJECT_NAME} APPEND_STRING PROPERTY LINK_FLAGS "${DELAYFLAGS}")
+    set_property(TARGET ${PROJECT_NAME} APPEND_STRING PROPERTY LINK_FLAGS "${DELAYFLAGS} /LTCG")
     if(USE_STATIC_MSVC)
         if(CMAKE_BUILD_TYPE MATCHES Debug)
             set_property(TARGET ${PROJECT_NAME} APPEND_STRING PROPERTY LINK_FLAGS " /NODEFAULTLIB:MSVCRTD")
@@ -366,5 +367,9 @@ endif()
 if(OpenSSL_FOUND)
     # include the libraries needed to use OpenSSL
     target_include_directories(${PROJECT_NAME} PRIVATE ${OpenSLL_INCLUDE_PATH})
-    target_link_libraries(${PROJECT_NAME} PRIVATE crypto)
-endif()
+    if((IOS) OR (MACOS))
+        target_link_libraries(${PROJECT_NAME} PRIVATE crypto -Wl,-dead_strip)
+    else()
+        target_link_libraries(${PROJECT_NAME} PRIVATE crypto -Wl,--gc-sections)
+    endif()
+endif()