Try to use smartlist_add_asprintf consistently

(To ensure correctness, in every case, make sure that the temporary
variable is deleted, renamed, or lowered in scope, so we can't have
any bugs related to accidentally relying on the no-longer-filled
variable.)

11 files changed, 92 insertions, 160 deletions

diff --git a/changes/clean_asprintf b/changes/clean_asprintf
new file mode 100644
index 0000000000..fc1613f8d0
--- /dev/null
+++ b/changes/clean_asprintf
@@ -0,0 +1,3 @@
+  o Code simplifications and refactoring
+    - Use the smartlist_add_asprintf alias more consistently
+      throughout the codebase.
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index a9e5d22943..216c926585 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -1545,15 +1545,13 @@ circuit_list_path_impl(origin_circuit_t *circ, int verbose, int verbose_names)
 
   if (verbose) {
     const char *nickname = build_state_get_exit_nickname(circ->build_state);
-    char *cp;
-    tor_asprintf(&cp, "%s%s circ (length %d%s%s):",
+    smartlist_add_asprintf(elements, "%s%s circ (length %d%s%s):",
                  circ->build_state->is_internal ? "internal" : "exit",
                  circ->build_state->need_uptime ? " (high-uptime)" : "",
                  circ->build_state->desired_path_len,
                  circ->_base.state == CIRCUIT_STATE_OPEN ? "" : ", last hop ",
                  circ->_base.state == CIRCUIT_STATE_OPEN ? "" :
                  (nickname?nickname:"*unnamed*"));
-    smartlist_add(elements, cp);
   }
 
   hop = circ->cpath;
@@ -3599,19 +3597,17 @@ log_entry_guards(int severity)
   SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e)
     {
       const char *msg = NULL;
-      char *cp;
       if (entry_is_live(e, 0, 1, 0, &msg))
-        tor_asprintf(&cp, "%s [%s] (up %s)",
+        smartlist_add_asprintf(elements, "%s [%s] (up %s)",
                      e->nickname,
                      hex_str(e->identity, DIGEST_LEN),
                      e->made_contact ? "made-contact" : "never-contacted");
       else
-        tor_asprintf(&cp, "%s [%s] (%s, %s)",
+        smartlist_add_asprintf(elements, "%s [%s] (%s, %s)",
                      e->nickname,
                      hex_str(e->identity, DIGEST_LEN),
                      msg,
                      e->made_contact ? "made-contact" : "never-contacted");
-      smartlist_add(elements, cp);
     }
   SMARTLIST_FOREACH_END(e);
 
diff --git a/src/or/config.c b/src/or/config.c
index 341bc15d21..d4a4e0349a 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -3147,11 +3147,9 @@ config_dump(const config_format_t *fmt, const void *default_options,
     line = assigned = get_assigned_option(fmt, options, fmt->vars[i].name, 1);
 
     for (; line; line = line->next) {
-      char *tmp;
-      tor_asprintf(&tmp, "%s%s %s\n",
+      smartlist_add_asprintf(elements, "%s%s %s\n",
                    comment_option ? "# " : "",
                    line->key, line->value);
-      smartlist_add(elements, tmp);
     }
     config_free_lines(assigned);
   }
@@ -3159,9 +3157,7 @@ config_dump(const config_format_t *fmt, const void *default_options,
   if (fmt->extra) {
     line = *(config_line_t**)STRUCT_VAR_P(options, fmt->extra->var_offset);
     for (; line; line = line->next) {
-      char *tmp;
-      tor_asprintf(&tmp, "%s %s\n", line->key, line->value);
-      smartlist_add(elements, tmp);
+      smartlist_add_asprintf(elements, "%s %s\n", line->key, line->value);
     }
   }
 
@@ -6994,7 +6990,6 @@ getinfo_helper_config(control_connection_t *conn,
     for (i = 0; _option_vars[i].name; ++i) {
       const config_var_t *var = &_option_vars[i];
       const char *type;
-      char *line;
       switch (var->type) {
         case CONFIG_TYPE_STRING: type = "String"; break;
         case CONFIG_TYPE_FILENAME: type = "Filename"; break;
@@ -7018,8 +7013,7 @@ getinfo_helper_config(control_connection_t *conn,
       }
       if (!type)
         continue;
-      tor_asprintf(&line, "%s %s\n",var->name,type);
-      smartlist_add(sl, line);
+      smartlist_add_asprintf(sl, "%s %s\n",var->name,type);
     }
     *answer = smartlist_join_strings(sl, "", 0, NULL);
     SMARTLIST_FOREACH(sl, char *, c, tor_free(c));
diff --git a/src/or/control.c b/src/or/control.c
index a6b8e4fa92..7bb11cd8c9 100644
--- a/src/or/control.c
+++ b/src/or/control.c
@@ -525,18 +525,15 @@ control_ports_write_to_file(void)
   lines = smartlist_create();
 
   SMARTLIST_FOREACH_BEGIN(get_connection_array(), const connection_t *, conn) {
-    char *port_str = NULL;
     if (conn->type != CONN_TYPE_CONTROL_LISTENER || conn->marked_for_close)
       continue;
 #ifdef AF_UNIX
     if (conn->socket_family == AF_UNIX) {
-      tor_asprintf(&port_str, "UNIX_PORT=%s\n", conn->address);
-      smartlist_add(lines, port_str);
+      smartlist_add_asprintf(lines, "UNIX_PORT=%s\n", conn->address);
       continue;
     }
 #endif
-    tor_asprintf(&port_str, "PORT=%s:%d\n", conn->address, conn->port);
-    smartlist_add(lines, port_str);
+    smartlist_add_asprintf(lines, "PORT=%s:%d\n", conn->address, conn->port);
   } SMARTLIST_FOREACH_END(conn);
 
   joined = smartlist_join_strings(lines, "", 0, NULL);
@@ -1558,7 +1555,6 @@ getinfo_helper_listeners(control_connection_t *control_conn,
 
   res = smartlist_create();
   SMARTLIST_FOREACH_BEGIN(get_connection_array(), connection_t *, conn) {
-    char *addr;
     struct sockaddr_storage ss;
     socklen_t ss_len = sizeof(ss);
 
@@ -1566,14 +1562,13 @@ getinfo_helper_listeners(control_connection_t *control_conn,
       continue;
 
     if (getsockname(conn->s, (struct sockaddr *)&ss, &ss_len) < 0) {
-      tor_asprintf(&addr, "%s:%d", conn->address, (int)conn->port);
+      smartlist_add_asprintf(res, "%s:%d", conn->address, (int)conn->port);
     } else {
       char *tmp = tor_sockaddr_to_str((struct sockaddr *)&ss);
-      addr = esc_for_log(tmp);
+      smartlist_add(res, esc_for_log(tmp));
       tor_free(tmp);
     }
-    if (addr)
-      smartlist_add(res, addr);
+
   } SMARTLIST_FOREACH_END(conn);
 
   *answer = smartlist_join_strings(res, " ", 0, NULL);
@@ -1798,7 +1793,6 @@ circuit_describe_status_for_controller(origin_circuit_t *circ)
   }
 
   {
-    char *buildflags = NULL;
     cpath_build_state_t *build_state = circ->build_state;
     smartlist_t *flaglist = smartlist_create();
     char *flaglist_joined;
@@ -1816,8 +1810,7 @@ circuit_describe_status_for_controller(origin_circuit_t *circ)
     if (smartlist_len(flaglist)) {
       flaglist_joined = smartlist_join_strings(flaglist, ",", 0, NULL);
 
-      tor_asprintf(&buildflags, "BUILD_FLAGS=%s", flaglist_joined);
-      smartlist_add(descparts, buildflags);
+      smartlist_add_asprintf(descparts, "BUILD_FLAGS=%s", flaglist_joined);
 
       tor_free(flaglist_joined);
     }
@@ -1825,43 +1818,29 @@ circuit_describe_status_for_controller(origin_circuit_t *circ)
     smartlist_free(flaglist);
   }
 
-  {
-    char *purpose = NULL;
-    tor_asprintf(&purpose, "PURPOSE=%s",
-                 circuit_purpose_to_controller_string(circ->_base.purpose));
-    smartlist_add(descparts, purpose);
-  }
+  smartlist_add_asprintf(descparts, "PURPOSE=%s",
+                    circuit_purpose_to_controller_string(circ->_base.purpose));
 
   {
-    char *hs_state_arg = NULL;
     const char *hs_state =
       circuit_purpose_to_controller_hs_state_string(circ->_base.purpose);
 
     if (hs_state != NULL) {
-      tor_asprintf(&hs_state_arg, "HS_STATE=%s",
-                   hs_state);
-
-      smartlist_add(descparts, hs_state_arg);
+      smartlist_add_asprintf(descparts, "HS_STATE=%s", hs_state);
     }
   }
 
   if (circ->rend_data != NULL) {
-    char *rend_query_arg = NULL;
-
-    tor_asprintf(&rend_query_arg, "REND_QUERY=%s",
+    smartlist_add_asprintf(descparts, "REND_QUERY=%s",
                  circ->rend_data->onion_address);
 
-    smartlist_add(descparts, rend_query_arg);
   }
 
   {
-    char *time_created_arg = NULL;
     char tbuf[ISO_TIME_USEC_LEN+1];
     format_iso_time_nospace_usec(tbuf, &circ->_base.timestamp_created);
 
-    tor_asprintf(&time_created_arg, "TIME_CREATED=%s", tbuf);
-
-    smartlist_add(descparts, time_created_arg);
+    smartlist_add_asprintf(descparts, "TIME_CREATED=%s", tbuf);
   }
 
   rv = smartlist_join_strings(descparts, " ", 0, NULL);
@@ -2218,18 +2197,16 @@ static char *
 list_getinfo_options(void)
 {
   int i;
-  char *buf=NULL;
   smartlist_t *lines = smartlist_create();
   char *ans;
   for (i = 0; getinfo_items[i].varname; ++i) {
     if (!getinfo_items[i].desc)
       continue;
 
-    tor_asprintf(&buf, "%s%s -- %s\n",
+    smartlist_add_asprintf(lines, "%s%s -- %s\n",
                  getinfo_items[i].varname,
                  getinfo_items[i].is_prefix ? "*" : "",
                  getinfo_items[i].desc);
-    smartlist_add(lines, buf);
   }
   smartlist_sort_strings(lines);
 
diff --git a/src/or/directory.c b/src/or/directory.c
index 12636bac33..8087d7603d 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -1124,7 +1124,6 @@ directory_send_command(dir_connection_t *conn,
   smartlist_t *headers = smartlist_create();
   char *url;
   char request[8192];
-  char *header;
   const char *httpcommand = NULL;
   size_t len;
 
@@ -1147,8 +1146,7 @@ directory_send_command(dir_connection_t *conn,
   if (if_modified_since) {
     char b[RFC1123_TIME_LEN+1];
     format_rfc1123_time(b, if_modified_since);
-    tor_asprintf(&header, "If-Modified-Since: %s\r\n", b);
-    smartlist_add(headers, header);
+    smartlist_add_asprintf(headers, "If-Modified-Since: %s\r\n", b);
   }
 
   /* come up with some proxy lines, if we're using one. */
@@ -1163,11 +1161,10 @@ directory_send_command(dir_connection_t *conn,
         log_warn(LD_BUG, "Encoding http authenticator failed");
     }
     if (base64_authenticator) {
-      tor_asprintf(&header,
+      smartlist_add_asprintf(headers,
                    "Proxy-Authorization: Basic %s\r\n",
                    base64_authenticator);
       tor_free(base64_authenticator);
-      smartlist_add(headers, header);
     }
   } else {
     proxystring[0] = 0;
@@ -1238,8 +1235,7 @@ directory_send_command(dir_connection_t *conn,
       httpcommand = "POST";
       url = tor_strdup("/tor/");
       if (why) {
-        tor_asprintf(&header, "X-Desc-Gen-Reason: %s\r\n", why);
-        smartlist_add(headers, header);
+        smartlist_add_asprintf(headers, "X-Desc-Gen-Reason: %s\r\n", why);
       }
       break;
     }
@@ -1294,15 +1290,16 @@ directory_send_command(dir_connection_t *conn,
   tor_free(url);
 
   if (!strcmp(httpcommand, "POST") || payload) {
-    tor_asprintf(&header, "Content-Length: %lu\r\n",
+    smartlist_add_asprintf(headers, "Content-Length: %lu\r\n",
                  payload ? (unsigned long)payload_len : 0);
-    smartlist_add(headers, header);
   }
 
-  header = smartlist_join_strings(headers, "", 0, NULL);
-  tor_snprintf(request, sizeof(request), " HTTP/1.0\r\nHost: %s\r\n%s\r\n",
-               hoststring, header);
-  tor_free(header);
+  {
+    char *header = smartlist_join_strings(headers, "", 0, NULL);
+    tor_snprintf(request, sizeof(request), " HTTP/1.0\r\nHost: %s\r\n%s\r\n",
+                 hoststring, header);
+    tor_free(header);
+  }
 
   connection_write_to_buf(request, strlen(request), TO_CONN(conn));
 
diff --git a/src/or/dirvote.c b/src/or/dirvote.c
index 3bb165aeea..72f49c7f47 100644
--- a/src/or/dirvote.c
+++ b/src/or/dirvote.c
@@ -1475,7 +1475,6 @@ networkstatus_compute_consensus(smartlist_t *votes,
   chunks = smartlist_create();
 
   {
-    char *buf=NULL;
     char va_buf[ISO_TIME_LEN+1], fu_buf[ISO_TIME_LEN+1],
       vu_buf[ISO_TIME_LEN+1];
     char *flaglist;
@@ -1484,20 +1483,17 @@ networkstatus_compute_consensus(smartlist_t *votes,
     format_iso_time(vu_buf, valid_until);
     flaglist = smartlist_join_strings(flags, " ", 0, NULL);
 
-    tor_asprintf(&buf, "network-status-version 3%s%s\n"
+    smartlist_add_asprintf(chunks, "network-status-version 3%s%s\n"
                  "vote-status consensus\n",
                  flavor == FLAV_NS ? "" : " ",
                  flavor == FLAV_NS ? "" : flavor_name);
 
-    smartlist_add(chunks, buf);
-
     if (consensus_method >= 2) {
-      tor_asprintf(&buf, "consensus-method %d\n",
+      smartlist_add_asprintf(chunks, "consensus-method %d\n",
                    consensus_method);
-      smartlist_add(chunks, buf);
     }
 
-    tor_asprintf(&buf,
+    smartlist_add_asprintf(chunks,
                  "valid-after %s\n"
                  "fresh-until %s\n"
                  "valid-until %s\n"
@@ -1508,7 +1504,6 @@ networkstatus_compute_consensus(smartlist_t *votes,
                  va_buf, fu_buf, vu_buf,
                  vote_seconds, dist_seconds,
                  client_versions, server_versions, flaglist);
-    smartlist_add(chunks, buf);
 
     tor_free(flaglist);
   }
@@ -1550,7 +1545,6 @@ networkstatus_compute_consensus(smartlist_t *votes,
       char votedigest[HEX_DIGEST_LEN+1];
       networkstatus_t *v = e->v;
       networkstatus_voter_info_t *voter = get_voter(v);
-      char *buf = NULL;
 
       if (e->is_legacy)
         tor_assert(consensus_method >= 2);
@@ -1559,20 +1553,18 @@ networkstatus_compute_consensus(smartlist_t *votes,
       base16_encode(votedigest, sizeof(votedigest), voter->vote_digest,
                     DIGEST_LEN);
 
-      tor_asprintf(&buf,
+      smartlist_add_asprintf(chunks,
                    "dir-source %s%s %s %s %s %d %d\n",
                    voter->nickname, e->is_legacy ? "-legacy" : "",
                    fingerprint, voter->address, fmt_addr32(voter->addr),
                    voter->dir_port,
                    voter->or_port);
-      smartlist_add(chunks, buf);
       if (! e->is_legacy) {
-        tor_asprintf(&buf,
+        smartlist_add_asprintf(chunks,
                      "contact %s\n"
                      "vote-digest %s\n",
                      voter->contact,
                      votedigest);
-        smartlist_add(chunks, buf);
       }
     } SMARTLIST_FOREACH_END(e);
     SMARTLIST_FOREACH(dir_sources, dir_src_ent_t *, e, tor_free(e));
@@ -1709,7 +1701,6 @@ networkstatus_compute_consensus(smartlist_t *votes,
       int naming_conflict = 0;
       int n_listing = 0;
       int i;
-      char *buf=NULL;
       char microdesc_digest[DIGEST256_LEN];
 
       /* Of the next-to-be-considered digest in each voter, which is first? */
@@ -1977,10 +1968,9 @@ networkstatus_compute_consensus(smartlist_t *votes,
       /*     Now an m line, if applicable. */
       if (flavor == FLAV_MICRODESC &&
           !tor_digest256_is_zero(microdesc_digest)) {
-        char m[BASE64_DIGEST256_LEN+1], *cp;
+        char m[BASE64_DIGEST256_LEN+1];
         digest256_to_base64(m, microdesc_digest);
-        tor_asprintf(&cp, "m %s\n", m);
-        smartlist_add(chunks, cp);
+        smartlist_add_asprintf(chunks, "m %s\n", m);
       }
       /*     Next line is all flags.  The "\n" is missing. */
       smartlist_add(chunks,
@@ -1993,15 +1983,12 @@ networkstatus_compute_consensus(smartlist_t *votes,
       smartlist_add(chunks, tor_strdup("\n"));
       /*     Now the weight line. */
       if (rs_out.has_bandwidth) {
-        char *cp=NULL;
-        tor_asprintf(&cp, "w Bandwidth=%d\n", rs_out.bandwidth);
-        smartlist_add(chunks, cp);
+        smartlist_add_asprintf(chunks, "w Bandwidth=%d\n", rs_out.bandwidth);
       }
 
       /*     Now the exitpolicy summary line. */
       if (rs_out.has_exitsummary && flavor == FLAV_NS) {
-        tor_asprintf(&buf, "p %s\n", rs_out.exitsummary);
-        smartlist_add(chunks, buf);
+        smartlist_add_asprintf(chunks, "p %s\n", rs_out.exitsummary);
       }
 
       /* And the loop is over and we move on to the next router */
@@ -2083,7 +2070,6 @@ networkstatus_compute_consensus(smartlist_t *votes,
     size_t digest_len =
       flavor == FLAV_NS ? DIGEST_LEN : DIGEST256_LEN;
     const char *algname = crypto_digest_algorithm_get_name(digest_alg);
-    char *buf = NULL;
     char sigbuf[4096];
 
     smartlist_add(chunks, tor_strdup("directory-signature "));
@@ -2097,14 +2083,13 @@ networkstatus_compute_consensus(smartlist_t *votes,
 
     /* add the junk that will go at the end of the line. */
     if (flavor == FLAV_NS) {
-      tor_asprintf(&buf, "%s %s\n", fingerprint,
+      smartlist_add_asprintf(chunks, "%s %s\n", fingerprint,
                    signing_key_fingerprint);
     } else {
-      tor_asprintf(&buf, "%s %s %s\n",
+      smartlist_add_asprintf(chunks, "%s %s %s\n",
                    algname, fingerprint,
                    signing_key_fingerprint);
     }
-    smartlist_add(chunks, buf);
     /* And the signature. */
     sigbuf[0] = '\0';
     if (router_append_dirobj_signature(sigbuf, sizeof(sigbuf),
@@ -2122,14 +2107,13 @@ networkstatus_compute_consensus(smartlist_t *votes,
       crypto_pk_get_fingerprint(legacy_signing_key,
                                 signing_key_fingerprint, 0);
       if (flavor == FLAV_NS) {
-        tor_asprintf(&buf, "%s %s\n", fingerprint,
+        smartlist_add_asprintf(chunks, "%s %s\n", fingerprint,
                      signing_key_fingerprint);
       } else {
-        tor_asprintf(&buf, "%s %s %s\n",
+        smartlist_add_asprintf(chunks, "%s %s %s\n",
                      algname, fingerprint,
                      signing_key_fingerprint);
       }
-      smartlist_add(chunks, buf);
       sigbuf[0] = '\0';
       if (router_append_dirobj_signature(sigbuf, sizeof(sigbuf),
                                          digest, digest_len,
diff --git a/src/or/geoip.c b/src/or/geoip.c
index 73194ae9c6..3e1ee5987f 100644
--- a/src/or/geoip.c
+++ b/src/or/geoip.c
@@ -856,9 +856,7 @@ geoip_get_client_history(geoip_client_action_t action)
   /* Build the result. */
   chunks = smartlist_create();
   SMARTLIST_FOREACH(entries, c_hist_t *, ch, {
-      char *buf=NULL;
-      tor_asprintf(&buf, "%s=%u", ch->country, ch->total);
-      smartlist_add(chunks, buf);
+      smartlist_add_asprintf(chunks, "%s=%u", ch->country, ch->total);
   });
   result = smartlist_join_strings(chunks, ",", 0, NULL);
  done:
@@ -907,10 +905,8 @@ geoip_get_request_history(geoip_client_action_t action)
 
   strings = smartlist_create();
   SMARTLIST_FOREACH(entries, c_hist_t *, ent, {
-      char *buf = NULL;
-      tor_asprintf(&buf, "%s=%u", ent->country, ent->total);
-      smartlist_add(strings, buf);
-    });
+      smartlist_add_asprintf(strings, "%s=%u", ent->country, ent->total);
+  });
   result = smartlist_join_strings(strings, ",", 0, NULL);
   SMARTLIST_FOREACH(strings, char *, cp, tor_free(cp));
   SMARTLIST_FOREACH(entries, c_hist_t *, ent, tor_free(ent));
diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c
index a835e78b85..0a1fc08bf7 100644
--- a/src/or/networkstatus.c
+++ b/src/or/networkstatus.c
@@ -598,39 +598,38 @@ networkstatus_check_consensus_signature(networkstatus_t *consensus,
                  hex_str(ds->v3_identity_digest, DIGEST_LEN));
       });
     {
+      char *joined;
       smartlist_t *sl = smartlist_create();
-      char *cp;
       char *tmp = smartlist_join_strings(list_good, " ", 0, NULL);
-      tor_asprintf(&cp, "A consensus needs %d good signatures from recognized "
+      smartlist_add_asprintf(sl,
+                   "A consensus needs %d good signatures from recognized "
                    "authorities for us to accept it. This one has %d (%s).",
                    n_required, n_good, tmp);
       tor_free(tmp);
-      smartlist_add(sl,cp);
       if (n_no_signature) {
         tmp = smartlist_join_strings(list_no_signature, " ", 0, NULL);
-        tor_asprintf(&cp, "%d (%s) of the authorities we know didn't sign it.",
+        smartlist_add_asprintf(sl,
+                     "%d (%s) of the authorities we know didn't sign it.",
                      n_no_signature, tmp);
         tor_free(tmp);
-        smartlist_add(sl,cp);
       }
       if (n_unknown) {
-        tor_asprintf(&cp, "It has %d signatures from authorities we don't "
+        smartlist_add_asprintf(sl,
+                      "It has %d signatures from authorities we don't "
                       "recognize.", n_unknown);
-        smartlist_add(sl,cp);
       }
       if (n_bad) {
-        tor_asprintf(&cp, "%d of the signatures on it didn't verify "
+        smartlist_add_asprintf(sl, "%d of the signatures on it didn't verify "
                       "correctly.", n_bad);
-        smartlist_add(sl,cp);
       }
       if (n_missing_key) {
-        tor_asprintf(&cp, "We were unable to check %d of the signatures, "
+        smartlist_add_asprintf(sl,
+                      "We were unable to check %d of the signatures, "
                       "because we were missing the keys.", n_missing_key);
-        smartlist_add(sl,cp);
       }
-      cp = smartlist_join_strings(sl, " ", 0, NULL);
-      log(severity, LD_DIR, "%s", cp);
-      tor_free(cp);
+      joined = smartlist_join_strings(sl, " ", 0, NULL);
+      log(severity, LD_DIR, "%s", joined);
+      tor_free(joined);
       SMARTLIST_FOREACH(sl, char *, c, tor_free(c));
       smartlist_free(sl);
     }
diff --git a/src/or/rephist.c b/src/or/rephist.c
index 6bbb93b821..b7bd2387fe 100644
--- a/src/or/rephist.c
+++ b/src/or/rephist.c
@@ -1588,7 +1588,6 @@ rep_hist_update_bwhist_state_section(or_state_t *state,
                                      time_t *s_begins,
                                      int *s_interval)
 {
-  char *cp;
   int i,j;
   uint64_t maxval;
 
@@ -1626,17 +1625,17 @@ rep_hist_update_bwhist_state_section(or_state_t *state,
   for (j=0; j < b->num_maxes_set; ++j,++i) {
     if (i >= NUM_TOTALS)
       i = 0;
-    tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(b->totals[i] & ~0x3ff));
-    smartlist_add(*s_values, cp);
+    smartlist_add_asprintf(*s_values, U64_FORMAT,
+                           U64_PRINTF_ARG(b->totals[i] & ~0x3ff));
     maxval = b->maxima[i] / NUM_SECS_ROLLING_MEASURE;
-    tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(maxval & ~0x3ff));
-    smartlist_add(*s_maxima, cp);
+    smartlist_add_asprintf(*s_maxima, U64_FORMAT,
+                           U64_PRINTF_ARG(maxval & ~0x3ff));
   }
-  tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(b->total_in_period & ~0x3ff));
-  smartlist_add(*s_values, cp);
+  smartlist_add_asprintf(*s_values, U64_FORMAT,
+                         U64_PRINTF_ARG(b->total_in_period & ~0x3ff));
   maxval = b->max_total / NUM_SECS_ROLLING_MEASURE;
-  tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(maxval & ~0x3ff));
-  smartlist_add(*s_maxima, cp);
+  smartlist_add_asprintf(*s_maxima, U64_FORMAT,
+                         U64_PRINTF_ARG(maxval & ~0x3ff));
 }
 
 /** Update <b>state</b> with the newest bandwidth history. Done before
@@ -2125,7 +2124,6 @@ rep_hist_format_exit_stats(time_t now)
   uint64_t cur_bytes = 0, other_read = 0, other_written = 0,
            total_read = 0, total_written = 0;
   uint32_t total_streams = 0, other_streams = 0;
-  char *buf;
   smartlist_t *written_strings, *read_strings, *streams_strings;
   char *written_string, *read_string, *streams_string;
   char t[ISO_TIME_LEN+1];
@@ -2204,9 +2202,8 @@ rep_hist_format_exit_stats(time_t now)
                      exit_bytes_written[cur_port],
                      EXIT_STATS_ROUND_UP_BYTES);
       num /= 1024;
-      buf = NULL;
-      tor_asprintf(&buf, "%d="U64_FORMAT, cur_port, U64_PRINTF_ARG(num));
-      smartlist_add(written_strings, buf);
+      smartlist_add_asprintf(written_strings, "%d="U64_FORMAT,
+                             cur_port, U64_PRINTF_ARG(num));
       other_written -= exit_bytes_written[cur_port];
     }
     if (exit_bytes_read[cur_port] > 0) {
@@ -2214,18 +2211,15 @@ rep_hist_format_exit_stats(time_t now)
                      exit_bytes_read[cur_port],
                      EXIT_STATS_ROUND_UP_BYTES);
       num /= 1024;
-      buf = NULL;
-      tor_asprintf(&buf, "%d="U64_FORMAT, cur_port, U64_PRINTF_ARG(num));
-      smartlist_add(read_strings, buf);
+      smartlist_add_asprintf(read_strings, "%d="U64_FORMAT,
+                             cur_port, U64_PRINTF_ARG(num));
       other_read -= exit_bytes_read[cur_port];
     }
     if (exit_streams[cur_port] > 0) {
       uint32_t num = round_uint32_to_next_multiple_of(
                      exit_streams[cur_port],
                      EXIT_STATS_ROUND_UP_STREAMS);
-      buf = NULL;
-      tor_asprintf(&buf, "%d=%u", cur_port, num);
-      smartlist_add(streams_strings, buf);
+      smartlist_add_asprintf(streams_strings, "%d=%u", cur_port, num);
       other_streams -= exit_streams[cur_port];
     }
   }
@@ -2234,20 +2228,16 @@ rep_hist_format_exit_stats(time_t now)
   other_written = round_uint64_to_next_multiple_of(other_written,
                   EXIT_STATS_ROUND_UP_BYTES);
   other_written /= 1024;
-  buf = NULL;
-  tor_asprintf(&buf, "other="U64_FORMAT, U64_PRINTF_ARG(other_written));
-  smartlist_add(written_strings, buf);
+  smartlist_add_asprintf(written_strings, "other="U64_FORMAT,
+                         U64_PRINTF_ARG(other_written));
   other_read = round_uint64_to_next_multiple_of(other_read,
                EXIT_STATS_ROUND_UP_BYTES);
   other_read /= 1024;
-  buf = NULL;
-  tor_asprintf(&buf, "other="U64_FORMAT, U64_PRINTF_ARG(other_read));
-  smartlist_add(read_strings, buf);
+  smartlist_add_asprintf(read_strings, "other="U64_FORMAT,
+                         U64_PRINTF_ARG(other_read));
   other_streams = round_uint32_to_next_multiple_of(other_streams,
                   EXIT_STATS_ROUND_UP_STREAMS);
-  buf = NULL;
-  tor_asprintf(&buf, "other=%u", other_streams);
-  smartlist_add(streams_strings, buf);
+  smartlist_add_asprintf(streams_strings, "other=%u", other_streams);
 
   /* Join all observations in single strings. */
   written_string = smartlist_join_strings(written_strings, ",", 0, NULL);
@@ -2468,7 +2458,6 @@ rep_hist_format_buffer_stats(time_t now)
   int processed_cells[SHARES], circs_in_share[SHARES],
       number_of_circuits, i;
   double queued_cells[SHARES], time_in_queue[SHARES];
-  char *buf = NULL;
   smartlist_t *processed_cells_strings, *queued_cells_strings,
               *time_in_queue_strings;
   char *processed_cells_string, *queued_cells_string,
@@ -2510,19 +2499,19 @@ rep_hist_format_buffer_stats(time_t now)
   queued_cells_strings = smartlist_create();
   time_in_queue_strings = smartlist_create();
   for (i = 0; i < SHARES; i++) {
-    tor_asprintf(&buf,"%d", !circs_in_share[i] ? 0 :
-                 processed_cells[i] / circs_in_share[i]);
-    smartlist_add(processed_cells_strings, buf);
+    smartlist_add_asprintf(processed_cells_strings,
+                           "%d", !circs_in_share[i] ? 0 :
+                              processed_cells[i] / circs_in_share[i]);
   }
   for (i = 0; i < SHARES; i++) {
-    tor_asprintf(&buf, "%.2f", circs_in_share[i] == 0 ? 0.0 :
-                 queued_cells[i] / (double) circs_in_share[i]);
-    smartlist_add(queued_cells_strings, buf);
+    smartlist_add_asprintf(queued_cells_strings, "%.2f",
+                           circs_in_share[i] == 0 ? 0.0 :
+                             queued_cells[i] / (double) circs_in_share[i]);
   }
   for (i = 0; i < SHARES; i++) {
-    tor_asprintf(&buf, "%.0f", circs_in_share[i] == 0 ? 0.0 :
-                 time_in_queue[i] / (double) circs_in_share[i]);
-    smartlist_add(time_in_queue_strings, buf);
+    smartlist_add_asprintf(time_in_queue_strings, "%.0f",
+                           circs_in_share[i] == 0 ? 0.0 :
+                             time_in_queue[i] / (double) circs_in_share[i]);
   }
 
   /* Join all observations in single strings. */
diff --git a/src/or/router.c b/src/or/router.c
index b2df3834fe..7d9d2724f7 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -2267,9 +2267,7 @@ extrainfo_dump_to_string(char **s_out, extrainfo_t *extrainfo,
   smartlist_add(chunks, pre);
 
   if (geoip_is_loaded()) {
-    char *chunk=NULL;
-    tor_asprintf(&chunk, "geoip-db-digest %s\n", geoip_db_digest());
-    smartlist_add(chunks, chunk);
+    smartlist_add_asprintf(chunks, "geoip-db-digest %s\n", geoip_db_digest());
   }
 
   if (options->ExtraInfoStatistics && write_stats_to_extrainfo) {
diff --git a/src/or/transports.c b/src/or/transports.c
index abf9d884f7..d8d2ff6aa6 100644
--- a/src/or/transports.c
+++ b/src/or/transports.c
@@ -918,7 +918,7 @@ parse_cmethod_line(const char *line, managed_proxy_t *mp)
 static char *
 get_bindaddr_for_proxy(const managed_proxy_t *mp)
 {
-  char *bindaddr = NULL;
+  char *bindaddr_result = NULL;
   char *bindaddr_tmp = NULL;
   smartlist_t *string_tmp = smartlist_create();
 
@@ -927,18 +927,17 @@ get_bindaddr_for_proxy(const managed_proxy_t *mp)
   SMARTLIST_FOREACH_BEGIN(mp->transports_to_launch, char *, t) {
     bindaddr_tmp = get_bindaddr_for_transport(t);
 
-    tor_asprintf(&bindaddr, "%s-%s", t, bindaddr_tmp);
-    smartlist_add(string_tmp, bindaddr);
+    smartlist_add_asprintf(string_tmp, "%s-%s", t, bindaddr_tmp);
 
     tor_free(bindaddr_tmp);
   } SMARTLIST_FOREACH_END(t);
 
-  bindaddr = smartlist_join_strings(string_tmp, ",", 0, NULL);
+  bindaddr_result = smartlist_join_strings(string_tmp, ",", 0, NULL);
 
   SMARTLIST_FOREACH(string_tmp, char *, t, tor_free(t));
   smartlist_free(string_tmp);
 
-  return bindaddr;
+  return bindaddr_result;
 }
 
 #ifdef MS_WINDOWS