+#if defined(LISP_FEATURE_SB_THREAD)
+static void
+preserve_context_registers (os_context_t *c)
+{
+ void **ptr;
+ /* On Darwin the signal context isn't a contiguous block of memory,
+ * so just preserve_pointering its contents won't be sufficient.
+ */
+#if defined(LISP_FEATURE_DARWIN)
+#if defined LISP_FEATURE_X86
+ preserve_pointer((void*)*os_context_register_addr(c,reg_EAX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_ECX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_EDX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_EBX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_ESI));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_EDI));
+ preserve_pointer((void*)*os_context_pc_addr(c));
+#elif defined LISP_FEATURE_X86_64
+ preserve_pointer((void*)*os_context_register_addr(c,reg_RAX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_RCX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_RDX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_RBX));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_RSI));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_RDI));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R8));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R9));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R10));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R11));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R12));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R13));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R14));
+ preserve_pointer((void*)*os_context_register_addr(c,reg_R15));
+ preserve_pointer((void*)*os_context_pc_addr(c));
+#else
+ #error "preserve_context_registers needs to be tweaked for non-x86 Darwin"
+#endif
+#endif
+ for(ptr = ((void **)(c+1))-1; ptr>=(void **)c; ptr--) {
+ preserve_pointer(*ptr);
+ }
+}
+#endif
+