Enable -Wconversion in src/platform/Darwin. (#25323)

Also fixes incorrect handling of the bssid from CWNetwork.

src/app/EventLoggingTypes.h

@@ -95,7 +95,7 @@ static_assert(sizeof(std::underlying_type_t<PriorityLevel>) <= sizeof(unsigned),
  */
 struct Timestamp
 {
-    enum class Type
+    enum class Type : uint8_t
     {
         kSystem = 0,
         kEpoch

src/app/util/af-types.h

@@ -35,6 +35,7 @@
 
 #include <app/ConcreteAttributePath.h>
 #include <app/data-model/Nullable.h>
+#include <lib/core/DataModelTypes.h>
 #include <lib/support/Variant.h>
 #include <messaging/ExchangeContext.h>
 
@@ -123,7 +124,7 @@ typedef struct
  */
 typedef struct
 {
-    uint16_t deviceId;
+    chip::DeviceTypeId deviceId;
     uint8_t deviceVersion;
 } EmberAfDeviceType;
 

src/include/platform/BuildTime.h

@@ -28,9 +28,9 @@
 // Example of __TIME__ string: "21:06:19"
 
 #define COMPUTE_BUILD_YEAR(_date)                                                                                                  \
-    (((_date)[7] - '0') * 1000 + ((_date)[8] - '0') * 100 + ((_date)[9] - '0') * 10 + ((_date)[10] - '0'))
+    static_cast<uint16_t>(((_date)[7] - '0') * 1000 + ((_date)[8] - '0') * 100 + ((_date)[9] - '0') * 10 + ((_date)[10] - '0'))
 
-#define COMPUTE_BUILD_DAY(_date) ((((_date)[4] >= '0') ? ((_date)[4] - '0') * 10 : 0) + ((_date)[5] - '0'))
+#define COMPUTE_BUILD_DAY(_date) static_cast<uint8_t>((((_date)[4] >= '0') ? ((_date)[4] - '0') * 10 : 0) + ((_date)[5] - '0'))
 
 #define BUILD_MONTH_IS_JAN(_date) ((_date)[0] == 'J' && (_date)[1] == 'a')
 #define BUILD_MONTH_IS_FEB(_date) ((_date)[0] == 'F')
@@ -63,9 +63,9 @@
                                                  ? 11                                                                              \
                                                  : (BUILD_MONTH_IS_DEC(_date)) ? 12 : /* error default */ 99)
 
-#define COMPUTE_BUILD_HOUR(_time) (((_time)[0] - '0') * 10 + (_time)[1] - '0')
-#define COMPUTE_BUILD_MIN(_time) (((_time)[3] - '0') * 10 + (_time)[4] - '0')
-#define COMPUTE_BUILD_SEC(_time) (((_time)[6] - '0') * 10 + (_time)[7] - '0')
+#define COMPUTE_BUILD_HOUR(_time) static_cast<uint8_t>(((_time)[0] - '0') * 10 + (_time)[1] - '0')
+#define COMPUTE_BUILD_MIN(_time) static_cast<uint8_t>(((_time)[3] - '0') * 10 + (_time)[4] - '0')
+#define COMPUTE_BUILD_SEC(_time) static_cast<uint8_t>(((_time)[6] - '0') * 10 + (_time)[7] - '0')
 
 #define BUILD_DATE_IS_BAD(_date) ((_date) == nullptr || strlen(_date) < strlen("Jan 01 2000") || (_date)[0] == '?')
 #define BUILD_TIME_IS_BAD(_time) ((_time) == nullptr || strlen(_time) < strlen("00:00:00") || (_time)[0] == '?')

src/messaging/tests/echo/echo_requester.cpp

@@ -184,7 +184,7 @@ void HandleEchoResponseReceived(chip::Messaging::ExchangeContext * ec, chip::Sys
     gEchoRespCount++;
 
     printf("Echo Response: %" PRIu64 "/%" PRIu64 "(%.2f%%) len=%u time=%.3fs\n", gEchoRespCount, gEchoCount,
-           static_cast<double>(gEchoRespCount) * 100 / gEchoCount, payload->DataLength(),
+           static_cast<double>(gEchoRespCount) * 100 / static_cast<double>(gEchoCount), payload->DataLength(),
            static_cast<double>(chip::System::Clock::Milliseconds32(transitTime).count()) / 1000);
 }
 

src/platform/Darwin/BUILD.gn

@@ -36,7 +36,10 @@ config("darwin_config") {
     ]
   }
 
-  cflags = [ "-fobjc-arc" ]
+  cflags = [
+    "-fobjc-arc",
+    "-Wconversion",
+  ]
 }
 
 static_library("Darwin") {
@@ -140,6 +143,9 @@ static_library("logging") {
   ]
 
   configs += [ "${chip_root}/src:includes" ]
-  cflags = [ "-fobjc-arc" ]
+  cflags = [
+    "-fobjc-arc",
+    "-Wconversion",
+  ]
   frameworks = [ "Foundation.framework" ]
 }

src/platform/Darwin/BleConnectionDelegateImpl.mm

@@ -175,7 +175,8 @@ - (void)resetTimer
 {
     auto timeout =
         [self hasDiscriminator] ? kScanningWithDiscriminatorTimeoutInSeconds : kScanningWithoutDiscriminatorTimeoutInSeconds;
-    dispatch_source_set_timer(_timer, dispatch_walltime(nullptr, timeout * NSEC_PER_SEC), DISPATCH_TIME_FOREVER, 5 * NSEC_PER_SEC);
+    dispatch_source_set_timer(
+        _timer, dispatch_walltime(nullptr, static_cast<int64_t>(timeout * NSEC_PER_SEC)), DISPATCH_TIME_FOREVER, 5 * NSEC_PER_SEC);
 }
 
 // All our callback dispatch must happen on _chipWorkQueue

src/platform/Darwin/ConnectivityManagerImpl.cpp

@@ -24,6 +24,7 @@
 #include <new>
 
 #include <lib/support/CodeUtils.h>
+#include <lib/support/SafeInt.h>
 #include <lib/support/logging/CHIPLogging.h>
 
 #include <platform/internal/GenericConnectivityManagerImpl_UDP.ipp>
@@ -80,6 +81,10 @@ CHIP_ERROR ConnectivityManagerImpl::GetEthernetInterfaceName(char * outName, siz
 {
     CHIP_ERROR err = CHIP_ERROR_NOT_IMPLEMENTED;
 #if TARGET_OS_OSX
+    if (!CanCastTo<CFIndex>(maxLen))
+    {
+        return CHIP_ERROR_INVALID_ARGUMENT;
+    }
     CFArrayRef interfaces = SCNetworkInterfaceCopyAll();
     VerifyOrReturnError(interfaces != nullptr, CHIP_ERROR_INTERNAL);
 
@@ -102,7 +107,7 @@ CHIP_ERROR ConnectivityManagerImpl::GetEthernetInterfaceName(char * outName, siz
             continue;
         }
 
-        if (!CFStringGetCString(interfaceName, outName, maxLen, kCFStringEncodingUTF8))
+        if (!CFStringGetCString(interfaceName, outName, static_cast<CFIndex>(maxLen), kCFStringEncodingUTF8))
         {
             continue;
         }

src/platform/Darwin/DnssdHostNameRegistrar.h

@@ -51,7 +51,8 @@ namespace Dnssd {
                 auto interfaceAddress = static_cast<const void *>(&interface.second);
                 auto interfaceAddressLen = sizeof(interface.second);
 
-                LogErrorOnFailure(RegisterInterface(interfaceId, type, interfaceAddress, interfaceAddressLen));
+                LogErrorOnFailure(
+                    RegisterInterface(interfaceId, type, interfaceAddress, static_cast<uint16_t>(interfaceAddressLen)));
             }
         }
 

src/platform/Darwin/WiFi/NetworkCommissioningWiFiDriver.mm

@@ -15,6 +15,7 @@
  *    limitations under the License.
  */
 
+#include <lib/support/BytesToHex.h>
 #include <lib/support/CodeUtils.h>
 #include <platform/CHIPDeviceLayer.h>
 #include <platform/Darwin/ConfigurationManagerImpl.h>
@@ -72,18 +73,23 @@ bool Next(WiFiScanResponse & scanResponse) override
     void CopyNetworkInformationTo(WiFiScanResponse & destination, CWNetwork * source)
     {
         destination.security = GetWiFiSecurity(source);
-        destination.ssidLen = [source.ssid length];
-        destination.channel = source.wlanChannel.channelNumber;
+        destination.channel = static_cast<uint16_t>(source.wlanChannel.channelNumber);
         destination.wiFiBand = GetWiFiBand(source.wlanChannel);
-        destination.rssi = source.rssiValue;
-        CopyStringTo(destination.ssid, source.ssid, DeviceLayer::Internal::kMaxWiFiSSIDLength);
-        CopyStringTo(destination.bssid, source.bssid, DeviceLayer::Internal::kWiFiBSSIDLength);
-    }
-
-    void CopyStringTo(uint8_t * destination, NSString * source, size_t maxLength)
-    {
-        NSData * data = [source dataUsingEncoding:NSUTF8StringEncoding];
-        memcpy(destination, [data bytes], std::min([data length], maxLength));
+        destination.rssi = static_cast<int8_t>(source.rssiValue);
+
+        NSData * ssidData = source.ssidData;
+        destination.ssidLen = static_cast<uint8_t>(std::min(ssidData.length, DeviceLayer::Internal::kMaxWiFiSSIDLength));
+        memcpy(destination.ssid, ssidData.bytes, destination.ssidLen);
+
+        // source.bssid looks like "00:00:00:00:00:00" if it's not nil.
+        NSString * bssid = source.bssid;
+        // 3 chars per byte, except the last byte.
+        if (bssid.length == 3 * sizeof(destination.bssid) - 1) {
+            const char * chars = bssid.UTF8String;
+            for (size_t i = 0; i < sizeof(destination.bssid); ++i) {
+                Encoding::HexToBytes(&chars[3 * i], 2, &destination.bssid[i], 1);
+            }
+        }
     }
 
     WiFiSecurity GetWiFiSecurity(CWNetwork * network)