CPack: Avoid using OS X CoreServices if compiler fails on header (#16021)

Some compilers on OS X report errors in the CoreServices framework headers.
Check for support of the header ahead of time and compile the relevant code
only when the header is available.

Source/CMakeLists.txt

@@ -728,7 +728,20 @@ endif()
 add_library(CPackLib ${CPACK_SRCS})
 target_link_libraries(CPackLib CMakeLib)
 if(APPLE)
-  target_link_libraries(CPackLib "-framework CoreServices")
+  # Some compilers produce errors in the CoreServices framework headers.
+  # Ideally such errors should be fixed by either the compiler vendor
+  # or the framework source, but we try to workaround it and build anyway.
+  # If it does not work, build with reduced functionality and warn.
+  check_include_file("CoreServices/CoreServices.h" HAVE_CoreServices)
+  if(HAVE_CoreServices)
+    set_property(SOURCE CPack/cmCPackDragNDropGenerator.cxx PROPERTY COMPILE_DEFINITIONS HAVE_CoreServices)
+    target_link_libraries(CPackLib "-framework CoreServices")
+  else()
+    message(WARNING "This compiler does not appear to support\n"
+      "  #include <CoreServices/CoreServices.h>\n"
+      "Some CPack functionality may be limited.\n"
+      "See CMakeFiles/CMakeError.log for details of the failure.")
+  endif()
 endif()
 
 if(APPLE)

Source/CPack/cmCPackDragNDropGenerator.cxx

@@ -22,10 +22,12 @@
 
 #include <CoreFoundation/CoreFoundation.h>
 
+#ifdef HAVE_CoreServices
 // For the old LocaleStringToLangAndRegionCodes() function, to convert
 // to the old Script Manager RegionCode values needed for the 'LPic' data
 // structure used for generating multi-lingual SLAs.
 #include <CoreServices/CoreServices.h>
+#endif
 
 static const char* SLAHeader =
 "data 'LPic' (5000) {\n"
@@ -643,9 +645,11 @@ int cmCPackDragNDropGenerator::CreateDMG(const std::string& src_dir,
                            kCFStringEncodingMacRoman);
         LangCode lang = 0;
         RegionCode region = 0;
+#ifdef HAVE_CoreServices
         OSStatus err = LocaleStringToLangAndRegionCodes(iso_language_cstr,
                                                         &lang, &region);
         if (err != noErr)
+#endif
           {
           cmCPackLogger(cmCPackLog::LOG_ERROR,
             "No language/region code available for " << iso_language_cstr
@@ -653,10 +657,12 @@ int cmCPackDragNDropGenerator::CreateDMG(const std::string& src_dir,
           free(iso_language_cstr);
           return 0;
           }
+#ifdef HAVE_CoreServices
         free(iso_language_cstr);
         header_data.push_back(region);
         header_data.push_back(i);
         header_data.push_back(0);
+#endif
         }
       ofs << "data 'LPic' (5000) {\n";
       ofs << std::hex << std::uppercase << std::setfill('0');