lowell@ubuntu:/usr/src/libobjc2-1.6$ make -f Makefile.clang Compiling arc.m... In file included from arc.m:7: ./class.h:285:14: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] return obj->isa; ^ arc.m:159:19: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] Class cls = obj->isa; ^ arc.m:176:19: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] Class cls = obj->isa; ^ 3 warnings generated. Compiling associate.m... In file included from associate.m:9: ./class.h:285:14: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] return obj->isa; ^ associate.m:186:19: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] Class cls = obj->isa; ^ associate.m:225:47: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] Class hiddenClass = allocateHiddenClass(obj->isa); ^ associate.m:226:33: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] assert(!class_isMetaClass(obj->isa)); ^ /usr/include/assert.h:92:5: note: expanded from macro 'assert' ((expr) \ ^ associate.m:235:7: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] obj->isa = hiddenClass; ^ associate.m:255:32: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] if (class_isMetaClass(object->isa)) ^ associate.m:314:32: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] if (class_isMetaClass(object->isa)) ^ associate.m:318:22: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] Class cls = object->isa; ^ associate.m:385:32: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] if (class_isMetaClass(object->isa)) ^ associate.m:387:18: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] return object->isa; ^ associate.m:423:40: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] id new = class_createInstance(object->isa, 0); ^ 11 warnings generated. Compiling gc_none.c... Compiling NSBlocks.m... In file included from NSBlocks.m:2: ./class.h:285:14: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] return obj->isa; ^ 1 warning generated. Compiling Protocol2.m... In file included from Protocol2.m:3: ./class.h:285:14: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] return obj->isa; ^ 1 warning generated. Compiling abi_version.c... Compiling alias_table.c... Compiling blocks_runtime.m... Compiling caps.c... Compiling category_loader.c... Compiling class_table.c... Compiling dtable.c... Compiling eh_personality.c... In file included from eh_personality.c:4: ./dwarf_eh.h:160:8: warning: case value not in enumerated type 'dwarf_data_encoding' [-Wswitch] case DW_EH_PE_absptr: ^ 1 warning generated. Compiling encoding2.c... Compiling hash_table.c... Compiling hooks.c... Compiling ivar.c... Compiling legacy_malloc.c... Compiling loader.c... Compiling mutation.m... Compiling properties.m... In file included from properties.m:7: ./class.h:285:14: warning: direct access to objective-c's isa is deprecated in favor of object_setClass() and object_getClass() [-Wdeprecated-objc-isa-usage] return obj->isa; ^ 1 warning generated. Compiling protocol.c... Compiling runtime.c... Compiling sarray2.c... Compiling selector_table.c... Compiling sendmsg2.c... Compiling statics_loader.c... Compiling toydispatch.c... Linking bitcode... Generating native object code... Linking shared library... /usr/bin/ld: libobjc.o: relocation R_X86_64_32 against `.data' can not be used when making a shared object; recompile with -fPIC libobjc.o: could not read symbols: Bad value clang: error: linker command failed with exit code 1 (use -v to see invocation) make: *** [libobjc.so.4] Error 1