+#ifdef LISP_FEATURE_DARWIN
+/* defined in ppc-darwin-os.c instead */
+#elif defined(LISP_FEATURE_FREEBSD)
+char *
+os_get_runtime_executable_path()
+{
+ char path[PATH_MAX + 1];
+ /* Defined on FreeBSD 6 and later. -- JES, 2006-02-06. */
+#ifdef KERN_PROC_PATHNAME
+ size_t len = PATH_MAX + 1;
+ int mib[4];
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_PROC;
+ mib[2] = KERN_PROC_PATHNAME;
+ mib[3] = -1;
+ if (sysctl(mib, 4, &path, &len, NULL, 0) != 0)
+ /* FIXME: Should we rather fall back into the /proc/-based
+ * code below, so that an SBCL executable core made on
+ * FreeBSD 6 would have at least some chance of working on
+ * FreeBSD 4? -- JES, 2006-02-06.
+ */
+ return NULL;
+#else
+ int size;
+ size = readlink("/proc/curproc/file", path, sizeof(path) - 1);
+ if (size < 0)
+ return NULL;
+ path[size] = '\0';
+ if (strcmp(path, "unknown") == 0)
+ return NULL;
+#endif
+ return copied_string(path);
+}
+#else /* Not DARWIN or FREEBSD */