Introduce a separate preprocessor macro, _LIBUNWIND_USE_DLADDR, for directly controlling a dependency on dladdr(). This will allow us to use libunwind without adding a libdl dependency.

libunwind/trunk/src/AddressSpace.hpp

 #ifndef __ADDRESSSPACE_HPP__
 #define __ADDRESSSPACE_HPP__
 
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#ifndef _LIBUNWIND_USE_DLADDR
   #if !defined(_LIBUNWIND_IS_BAREMETAL) && !defined(_WIN32)
+    #define _LIBUNWIND_USE_DLADDR 1
+  #else
+    #define _LIBUNWIND_USE_DLADDR 0
+  #endif
+#endif
+
+#if _LIBUNWIND_USE_DLADDR
 #include <dlfcn.h>
 #endif
 
 #ifdef __APPLE__
 #include <mach-o/getsect.h>
 namespace libunwind {
    bool checkKeyMgrRegisteredFDEs(uintptr_t targetAddr, void *&fde);
 }
#else
   (void)fde;
   return false;
 #endif
 }
 
 inline bool LocalAddressSpace::findFunctionName(pint_t addr, char *buf,
                                                 size_t bufLen,
                                                 unw_word_t *offset) {
-#if !defined(_LIBUNWIND_IS_BAREMETAL) && !defined(_WIN32)
+#if _LIBUNWIND_USE_DLADDR
   Dl_info dyldInfo;
   if (dladdr((void *)addr, &dyldInfo)) {
     if (dyldInfo.dli_sname != NULL) {
       snprintf(buf, bufLen, "%s", dyldInfo.dli_sname);
       *offset = (addr - (pint_t) dyldInfo.dli_saddr);
       return true;
     }
   }