lib,rlc: changed return of string helper functions from char* to std::string to avoid UB

lib/include/srsran/rlc/rlc_am_lte_packing.h

@@ -62,8 +62,8 @@ bool     rlc_am_is_unaligned(const uint8_t fi);
 bool     rlc_am_not_start_aligned(const uint8_t fi);
 std::string
 rlc_am_undelivered_sdu_info_to_string(const std::map<uint32_t, pdcp_pdu_info<rlc_amd_pdu_header_t> >& info_queue);
-const char* rlc_amd_pdu_header_to_string(const rlc_amd_pdu_header_t& header);
-const char* rlc_am_status_pdu_to_string(rlc_status_pdu_t* status);
+std::string rlc_amd_pdu_header_to_string(const rlc_amd_pdu_header_t& header);
+std::string rlc_am_status_pdu_to_string(rlc_status_pdu_t* status);
 } // namespace srsran
 
 #endif // SRSRAN_RLC_AM_LTE_PACKING_H

lib/src/rlc/rlc_am_lte.cc

@@ -420,7 +420,7 @@ bool rlc_am_lte_tx::poll_required()
 
   /* According to 5.2.2.1 in 36.322 v13.3.0 a poll should be requested if
    * the entire AM window is unacknowledged, i.e. no new PDU can be transmitted.
-   * However, it seems more appropiate to request more often if polling
+   * However, it seems more appropriate to request more often if polling
    * is disabled otherwise, e.g. every N PDUs.
    */
   if (cfg.poll_pdu == 0 && cfg.poll_byte == 0 && vt_s % rlc_am::poll_periodicity == 0) {

lib/src/rlc/rlc_am_lte_packing.cc

@@ -312,7 +312,7 @@ bool rlc_am_not_start_aligned(const uint8_t fi)
 /**
  * Logging helpers
  */
-const char* rlc_amd_pdu_header_to_string(const rlc_amd_pdu_header_t& header)
+std::string rlc_amd_pdu_header_to_string(const rlc_amd_pdu_header_t& header)
 {
   fmt::memory_buffer buffer;
   fmt::format_to(buffer,
@@ -334,10 +334,10 @@ const char* rlc_amd_pdu_header_to_string(const rlc_amd_pdu_header_t& header)
   }
   fmt::format_to(buffer, "]");
 
-  return to_c_str(buffer);
+  return fmt::to_string(buffer);
 }
 
-const char* rlc_am_status_pdu_to_string(rlc_status_pdu_t* status)
+std::string rlc_am_status_pdu_to_string(rlc_status_pdu_t* status)
 {
   fmt::memory_buffer buffer;
   fmt::format_to(buffer, "ACK_SN = {}, N_nack = {}", status->ack_sn, status->N_nack);
@@ -352,7 +352,7 @@ const char* rlc_am_status_pdu_to_string(rlc_status_pdu_t* status)
       }
     }
   }
-  return to_c_str(buffer);
+  return fmt::to_string(buffer);
 }
 
 } // namespace srsran