[CMake] Give Mach-O arm64 binaries an ad-hoc signature

Also lower platform requirement to Catalina (was Big-Sur)

Signed-off-by: AeroStun <[email protected]>

Author: AeroStun

.github/workflows/build.yml

@@ -215,7 +215,7 @@ jobs:
           export OPENSSL_ROOT_DIR=$(brew --prefix openssl@3)
           mkdir build
           cmake -G Ninja \
-            -DCMAKE_OSX_DEPLOYMENT_TARGET=10.13 \
+            -DCMAKE_OSX_DEPLOYMENT_TARGET=10.15\
             -DCMAKE_OSX_ARCHITECTURES="x86_64;arm64" \
             -DCMAKE_BUILD_TYPE=Release \
             -DSMCE_CXXRT_LINKING=STATIC \

CMake/Modules/AdHocSign.cmake

@@ -1,17 +1,19 @@
 
 set (OSX_NEEDS_SIGN False)
 if (APPLE AND NOT CMAKE_HOST_SYSTEM_PROCESSOR STREQUAL "arm64")
-  list (FIND CMAKE_OSX_ARCHITECTURES "arm64" osx_target_arm64)
+  string (FIND "${CMAKE_OSX_ARCHITECTURES}" "arm64" osx_target_arm64)
   if (osx_target_arm64 GREATER_EQUAL 0)
+    message (STATUS "Targeting Apple Silicon - ad-hoc signatures required")
     set (OSX_NEEDS_SIGN True)
     find_program (CODESIGN_EXECUTABLE codesign REQUIRED)
   endif()
 endif ()
 
-function (ad_hoc_sign target)
+macro (ad_hoc_sign target)
   if (OSX_NEEDS_SIGN)
     add_custom_command (TARGET "${target}" POST_BUILD
         COMMAND "${CODESIGN_EXECUTABLE}" --force --deep -s - --digest-algorithm=sha1,sha256 "$<TARGET_FILE:${target}>"
+        COMMENT "Stamping ad-hoc signature on target ${target}"
     )
   endif ()
-endfunction ()
+endmacro ()