[style] apply missing const declarations (#3921)

src/core/coap/coap_secure.hpp

@@ -123,7 +123,7 @@ public:
      * @retval FALSE If DTLS session is not active.
      *
      */
-    bool IsConnectionActive(void) { return mDtls.IsConnectionActive(); }
+    bool IsConnectionActive(void) const { return mDtls.IsConnectionActive(); }
 
     /**
      * This method indicates whether or not the DTLS session is connected.
@@ -132,7 +132,7 @@ public:
      * @retval FALSE  The DTLS session is not connected.
      *
      */
-    bool IsConnected(void) { return mDtls.IsConnected(); }
+    bool IsConnected(void) const { return mDtls.IsConnected(); }
 
     /**
      * This method stops the DTLS connection.

src/core/common/settings.hpp

@@ -383,7 +383,7 @@ public:
          * @retval FALSE  The current entry is valid.
          *
          */
-        bool IsDone(void) { return mIsDone; }
+        bool IsDone(void) const { return mIsDone; }
 
         /**
          * This method advances the iterator to move to the next Child Info entry in the list (if any).

src/core/common/tasklet.hpp

@@ -164,7 +164,7 @@ public:
      * @retval FALSE  If there are no tasklets pending.
      *
      */
-    bool AreTaskletsPending(void) { return mHead != NULL; }
+    bool AreTaskletsPending(void) const { return mHead != NULL; }
 
     /**
      * This method processes all tasklets queued when this is called.

src/core/mac/mac.cpp

@@ -172,17 +172,7 @@ void Mac::Scan(Operation aScanOperation, uint32_t aScanChannels, uint16_t aScanD
     StartOperation(aScanOperation);
 }
 
-bool Mac::IsActiveScanInProgress(void)
-{
-    return (mOperation == kOperationActiveScan) || (mPendingActiveScan);
-}
-
-bool Mac::IsEnergyScanInProgress(void)
-{
-    return (mOperation == kOperationEnergyScan) || (mPendingEnergyScan);
-}
-
-bool Mac::IsInTransmitState(void)
+bool Mac::IsInTransmitState(void) const
 {
     return (mOperation == kOperationTransmitData) || (mOperation == kOperationTransmitBeacon) ||
            (mOperation == kOperationTransmitOutOfBandFrame);

src/core/mac/mac.hpp

@@ -466,13 +466,13 @@ public:
      * This method returns if an active scan is in progress.
      *
      */
-    bool IsActiveScanInProgress(void);
+    bool IsActiveScanInProgress(void) const { return (mOperation == kOperationActiveScan) || (mPendingActiveScan); }
 
     /**
      * This method returns if an energy scan is in progress.
      *
      */
-    bool IsEnergyScanInProgress(void);
+    bool IsEnergyScanInProgress(void) const { return (mOperation == kOperationEnergyScan) || (mPendingEnergyScan); }
 
     /**
      * This method returns if the MAC layer is in transmit state.
@@ -482,7 +482,7 @@ public:
      * Requests.
      *
      */
-    bool IsInTransmitState(void);
+    bool IsInTransmitState(void) const;
 
     /**
      * This method registers a callback to provide received raw IEEE 802.15.4 frames.
@@ -564,7 +564,7 @@ public:
      * @retval false  Link layer is not enabled.
      *
      */
-    bool IsEnabled(void) { return mEnabled; }
+    bool IsEnabled(void) const { return mEnabled; }
 
     /**
      * This method performs AES CCM on the frame which is going to be sent.

src/core/mac/mac_filter.cpp

@@ -142,13 +142,13 @@ void Filter::ClearAddresses(void)
     }
 }
 
-otError Filter::GetNextAddress(Iterator &aIterator, Entry &aEntry)
+otError Filter::GetNextAddress(Iterator &aIterator, Entry &aEntry) const
 {
     otError error = OT_ERROR_NOT_FOUND;
 
     for (; aIterator < OT_ARRAY_LENGTH(mFilterEntries); aIterator++)
     {
-        FilterEntry &entry = mFilterEntries[aIterator];
+        const FilterEntry &entry = mFilterEntries[aIterator];
 
         if (entry.mFiltered)
         {

src/core/mac/mac_filter.hpp

@@ -144,7 +144,7 @@ public:
      * @retval OT_ERROR_NOT_FOUND  No subsequent entry exists.
      *
      */
-    otError GetNextAddress(Iterator &aIterator, Entry &aEntry);
+    otError GetNextAddress(Iterator &aIterator, Entry &aEntry) const;
 
     /**
      * This method sets the received signal strength for the messages from the Extended Address.

src/core/mac/mac_frame.hpp

@@ -1319,7 +1319,7 @@ public:
      * @retval FALSE if the beacon does not appear to be a valid Thread Beacon message.
      *
      */
-    bool IsValid(void)
+    bool IsValid(void) const
     {
         return (mSuperframeSpec == ot::Encoding::LittleEndian::HostSwap16(kSuperFrameSpec)) && (mGtsSpec == 0) &&
                (mPendingAddressSpec == 0);
@@ -1387,7 +1387,7 @@ public:
      * @retval FALSE if the beacon does not appear to be a valid Thread Beacon Payload.
      *
      */
-    bool IsValid(void) { return (mProtocolId == kProtocolId); }
+    bool IsValid(void) const { return (mProtocolId == kProtocolId); }
 
     /**
      * This method returns the Protocol ID value.

src/core/meshcop/dataset_manager.hpp

@@ -408,8 +408,6 @@ private:
 #if OPENTHREAD_FTD
     static void HandleSet(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo);
     void        HandleSet(Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
-
-    bool IsTlvInitialized(Tlv::Type aType);
 #endif
 
     Coap::Resource mResourceGet;

src/core/meshcop/joiner_router.hpp

@@ -216,7 +216,7 @@ public:
      * @retval TRUE   If the message shall be sent before the given time.
      * @retval FALSE  Otherwise.
      */
-    bool IsEarlier(uint32_t aTime) { return (static_cast<int32_t>(aTime - mSendTime) > 0); }
+    bool IsEarlier(uint32_t aTime) const { return (static_cast<int32_t>(aTime - mSendTime) > 0); }
 
     /**
      * This method checks if the message shall be sent after the given time.
@@ -226,7 +226,7 @@ public:
      * @retval TRUE   If the message shall be sent after the given time.
      * @retval FALSE  Otherwise.
      */
-    bool IsLater(uint32_t aTime) { return (static_cast<int32_t>(aTime - mSendTime) < 0); }
+    bool IsLater(uint32_t aTime) const { return (static_cast<int32_t>(aTime - mSendTime) < 0); }
 
 private:
     Ip6::MessageInfo mMessageInfo;                    ///< Message info of the message to send.

src/core/meshcop/meshcop_tlvs.hpp

@@ -2445,7 +2445,7 @@ public:
      * @retval FALSE  If the Joiner flag is not set.
      *
      */
-    bool IsJoiner(void) { return (mFlags & kJoinerMask) != 0; }
+    bool IsJoiner(void) const { return (mFlags & kJoinerMask) != 0; }
 
     /**
      * This method sets the Joiner flag.
@@ -2532,7 +2532,7 @@ public:
      * @retval FALSE  If the Native Commissioner flag is not set.
      *
      */
-    bool IsNativeCommissioner(void) { return (mFlags & kNativeMask) != 0; }
+    bool IsNativeCommissioner(void) const { return (mFlags & kNativeMask) != 0; }
 
     /**
      * This method sets the Native Commissioner flag.

src/core/net/ip6.hpp

@@ -279,7 +279,7 @@ public:
      * @sa SetReceiveIp6FilterEnabled
      *
      */
-    bool IsReceiveIp6FilterEnabled(void) { return mIsReceiveIp6FilterEnabled; }
+    bool IsReceiveIp6FilterEnabled(void) const { return mIsReceiveIp6FilterEnabled; }
 
     /**
      * This method sets whether or not Thread control traffic is filtered out when delivering IPv6 datagrams
@@ -299,7 +299,7 @@ public:
      * @returns TRUE if IPv6 forwarding is enabled, FALSE otherwise.
      *
      */
-    bool IsForwardingEnabled(void) { return mForwardingEnabled; }
+    bool IsForwardingEnabled(void) const { return mForwardingEnabled; }
 
     /**
      * This method enables/disables IPv6 forwarding.

src/core/net/ip6_headers.hpp

@@ -576,7 +576,7 @@ public:
      * @returns The Fragment Offset value.
      *
      */
-    uint16_t GetOffset(void) { return (HostSwap16(mOffsetMore) & kOffsetMask) >> kOffsetOffset; }
+    uint16_t GetOffset(void) const { return (HostSwap16(mOffsetMore) & kOffsetMask) >> kOffsetOffset; }
 
     /**
      * This method sets the Fragment Offset value.
@@ -596,7 +596,7 @@ public:
      * @returns The M flag value.
      *
      */
-    bool IsMoreFlagSet(void) { return HostSwap16(mOffsetMore) & kMoreFlag; }
+    bool IsMoreFlagSet(void) const { return HostSwap16(mOffsetMore) & kMoreFlag; }
 
     /**
      * This method clears the M flag value.

src/core/net/ip6_mpl.hpp

@@ -125,7 +125,7 @@ public:
      * @retval FALSE  If the MPL M flag is not set.
      *
      */
-    bool IsMaxFlagSet(void) { return (mControl & kMaxFlag) != 0; }
+    bool IsMaxFlagSet(void) const { return (mControl & kMaxFlag) != 0; }
 
     /**
      * This method clears the MPL M flag.

src/core/net/netif.cpp

@@ -302,23 +302,22 @@ exit:
     return error;
 }
 
-otError Netif::GetNextExternalMulticast(uint8_t &aIterator, Address &aAddress)
+otError Netif::GetNextExternalMulticast(uint8_t &aIterator, Address &aAddress) const
 {
-    otError                error = OT_ERROR_NOT_FOUND;
-    size_t                 num   = OT_ARRAY_LENGTH(mExtMulticastAddresses);
-    NetifMulticastAddress *entry;
+    otError error = OT_ERROR_NOT_FOUND;
+    size_t  num   = OT_ARRAY_LENGTH(mExtMulticastAddresses);
 
     VerifyOrExit(aIterator < num);
 
     // Find an available entry in the `mExtMulticastAddresses` array.
     for (uint8_t i = aIterator; i < num; i++)
     {
-        entry = &mExtMulticastAddresses[i];
+        const NetifMulticastAddress &entry = mExtMulticastAddresses[i];
 
         // In an unused/available entry, `mNext` points back to the entry itself.
-        if (entry->mNext != entry)
+        if (entry.mNext != &entry)
         {
-            aAddress  = entry->GetAddress();
+            aAddress  = entry.GetAddress();
             aIterator = i + 1;
             ExitNow(error = OT_ERROR_NONE);
         }

src/core/net/netif.hpp

@@ -360,7 +360,7 @@ public:
      * @retval OT_ERROR_NOT_FOUND  No subsequent external multicast address.
      *
      */
-    otError GetNextExternalMulticast(uint8_t &aIterator, Address &aAddress);
+    otError GetNextExternalMulticast(uint8_t &aIterator, Address &aAddress) const;
 
     /**
      * This method subscribes the network interface to the external (to OpenThread) multicast address.
@@ -400,7 +400,7 @@ public:
      * @retval TRUE   If the multicast promiscuous mode is enabled.
      * @retval FALSE  If the multicast promiscuous mode is disabled.
      */
-    bool IsMulticastPromiscuousEnabled(void) { return mMulticastPromiscuous; }
+    bool IsMulticastPromiscuousEnabled(void) const { return mMulticastPromiscuous; }
 
     /**
      * This method enables multicast promiscuous mode on the network interface.

src/core/thread/mesh_forwarder.cpp

@@ -385,7 +385,7 @@ exit:
     return error;
 }
 
-bool MeshForwarder::GetRxOnWhenIdle(void)
+bool MeshForwarder::GetRxOnWhenIdle(void) const
 {
     return Get<Mac::Mac>().GetRxOnWhenIdle();
 }

src/core/thread/mesh_forwarder.hpp

@@ -219,7 +219,7 @@ public:
      * @retval FALSE  The rx-on-when-idle-mode is disabled.
      *
      */
-    bool GetRxOnWhenIdle(void);
+    bool GetRxOnWhenIdle(void) const;
 
     /**
      * This method sets the rx-on-when-idle mode

src/core/thread/mle_router_ftd.hpp

@@ -282,7 +282,7 @@ public:
      * @returns The current router selection jitter timeout value.
      *
      */
-    uint8_t GetRouterSelectionJitterTimeout(void) { return mRouterSelectionJitterTimeout; }
+    uint8_t GetRouterSelectionJitterTimeout(void) const { return mRouterSelectionJitterTimeout; }
 
     /**
      * This method returns the ROUTER_UPGRADE_THRESHOLD value.

src/core/thread/mle_router_mtd.hpp

@@ -62,12 +62,12 @@ public:
 
     bool IsRouterRoleEnabled(void) const { return false; }
 
-    bool IsSingleton(void) { return false; }
+    bool IsSingleton(void) const { return false; }
 
     otError BecomeRouter(ThreadStatusTlv::Status) { return OT_ERROR_NOT_CAPABLE; }
     otError BecomeLeader(void) { return OT_ERROR_NOT_CAPABLE; }
 
-    uint8_t GetRouterSelectionJitterTimeout(void) { return 0; }
+    uint8_t GetRouterSelectionJitterTimeout(void) const { return 0; }
 
     uint32_t GetPreviousPartitionId(void) const { return 0; }
     void     SetPreviousPartitionId(uint32_t) {}
@@ -84,7 +84,7 @@ public:
     otError RemoveNeighbor(const Mac::Address &) { return BecomeDetached(); }
     otError RemoveNeighbor(Neighbor &) { return BecomeDetached(); }
 
-    bool IsMinimalChild(uint16_t) { return false; }
+    bool IsMinimalChild(uint16_t) const { return false; }
 
     void    RestoreChildren(void) {}
     otError RemoveStoredChild(uint16_t) { return OT_ERROR_NOT_IMPLEMENTED; }

src/core/thread/mle_tlvs.hpp

@@ -1152,7 +1152,7 @@ public:
      * @retval OT_ERROR_NOT_FOUND   No subsequent Tlv exists in TlvRequestTlv.
      *
      */
-    otError GetNextTlv(TlvRequestIterator &aIterator, uint8_t &aTlv)
+    otError GetNextTlv(TlvRequestIterator &aIterator, uint8_t &aTlv) const
     {
         otError error = OT_ERROR_NOT_FOUND;
 
@@ -1233,7 +1233,7 @@ public:
      * @retval TRUE   If the Router flag is set.
      * @retval FALSE  If the Router flag is not set.
      */
-    bool IsRouterFlagSet(void) { return (mMask & kRouterFlag) != 0; }
+    bool IsRouterFlagSet(void) const { return (mMask & kRouterFlag) != 0; }
 
     /**
      * This method clears the End Device flag.
@@ -1253,7 +1253,7 @@ public:
      * @retval TRUE   If the End Device flag is set.
      * @retval FALSE  If the End Device flag is not set.
      */
-    bool IsEndDeviceFlagSet(void) { return (mMask & kEndDeviceFlag) != 0; }
+    bool IsEndDeviceFlagSet(void) const { return (mMask & kEndDeviceFlag) != 0; }
 
     /**
      * This method sets the Mask byte value.

src/core/utils/channel_manager.hpp

@@ -196,7 +196,7 @@ public:
      * @returns The interval (in seconds).
      *
      */
-    uint32_t GetAutoChannelSelectionInterval(void) { return mAutoSelectInterval; }
+    uint32_t GetAutoChannelSelectionInterval(void) const { return mAutoSelectInterval; }
 
     /**
      * This method gets the supported channel mask.

src/ncp/ncp_base.hpp

@@ -225,7 +225,7 @@ protected:
                                                    uint16_t          aValueLen);
 
     otError SendQueuedResponses(void);
-    bool    IsResponseQueueEmpty(void) { return (mResponseQueueHead == mResponseQueueTail); }
+    bool    IsResponseQueueEmpty(void) const { return (mResponseQueueHead == mResponseQueueTail); }
     otError EnqueueResponse(uint8_t aHeader, ResponseType aType, unsigned int aPropKeyOrStatus);
 
     otError PrepareGetResponse(uint8_t aHeader, spinel_prop_key_t aPropKey)