Fix up put as well as naming for null value and comment

project-chip · Oct 28, 2024 · 1ac822c · 1ac822c
1 parent 2a75a2e
commit 1ac822c
Showing 1 changed file with 11 additions and 13 deletions.
diff --git a/src/app/codegen-data-model-provider/EmberAttributeDataBuffer.cpp b/src/app/codegen-data-model-provider/EmberAttributeDataBuffer.cpp
@@ -387,19 +387,19 @@ CHIP_ERROR EmberAttributeDataBuffer::EncodeInteger(chip::TLV::TLVWriter & writer
     const bool isSigned = chip::app::IsSignedAttributeType(mAttributeType);
 
     unsigned byteCount;
-    uint64_t nullValue;
+    uint64_t nullValueAsU64;
 
     if (isSigned)
     {
         const SignedDecodeInfo info = GetSignedDecodeInfo(mAttributeType);
         byteCount                   = info.byteCount;
-        nullValue                   = static_cast<uint64_t>(info.minValue); // just a bit cast for easy compare
+        nullValueAsU64              = static_cast<uint64_t>(info.minValue);
     }
     else
     {
         const UnsignedDecodeInfo info = GetUnsignedDecodeInfo(mAttributeType);
         byteCount                     = info.byteCount;
-        nullValue                     = info.maxValue;
+        nullValueAsU64                = info.maxValue;
     }
 
     VerifyOrDie(sizeof(raw_bytes) >= byteCount);
@@ -438,6 +438,10 @@ CHIP_ERROR EmberAttributeDataBuffer::EncodeInteger(chip::TLV::TLVWriter & writer
         value.uint_value = (value.uint_value & ~0xFFULL) | raw_bytes[i];
     }
 
+    // We place the null value as either int_value or uint_value into a union that is
+    // bit-formatted as both int64 and uint64. When we define the nullValue,
+    // it is bitcast into u64 hence this comparison. This is ugly, however this
+    // code prioritizes code size over readability here.
     if (mIsNullable && (value.uint_value == nullValue))
     {
         // MaxValue is used for NULL setting
@@ -446,27 +450,21 @@ CHIP_ERROR EmberAttributeDataBuffer::EncodeInteger(chip::TLV::TLVWriter & writer
 
     switch (mAttributeType)
     {
-    case ZCL_INT8U_ATTRIBUTE_TYPE: // Unsigned 8-bit integer
-        return writer.Put(tag, static_cast<uint8_t>(value.uint_value));
+    case ZCL_INT8U_ATTRIBUTE_TYPE:  // Unsigned 8-bit integer
     case ZCL_INT16U_ATTRIBUTE_TYPE: // Unsigned 16-bit integer
-        return writer.Put(tag, static_cast<uint16_t>(value.uint_value));
     case ZCL_INT24U_ATTRIBUTE_TYPE: // Unsigned 24-bit integer
     case ZCL_INT32U_ATTRIBUTE_TYPE: // Unsigned 32-bit integer
-        return writer.Put(tag, static_cast<uint32_t>(value.uint_value));
     case ZCL_INT40U_ATTRIBUTE_TYPE: // Unsigned 40-bit integer
     case ZCL_INT48U_ATTRIBUTE_TYPE: // Unsigned 48-bit integer
     case ZCL_INT56U_ATTRIBUTE_TYPE: // Signed 56-bit integer
     case ZCL_INT64U_ATTRIBUTE_TYPE: // Signed 64-bit integer
-        return writer.Put(tag, static_cast<uint64_t>(value.uint_value));
-    case ZCL_INT8S_ATTRIBUTE_TYPE: // Signed 8-bit integer
-        return writer.Put(tag, static_cast<int8_t>(value.int_value));
+        return writer.Put(tag, value.uint_value);
+    case ZCL_INT8S_ATTRIBUTE_TYPE:  // Signed 8-bit integer
     case ZCL_INT16S_ATTRIBUTE_TYPE: // Signed 16-bit integer
-        return writer.Put(tag, static_cast<int16_t>(value.int_value));
     case ZCL_INT24S_ATTRIBUTE_TYPE: // Signed 24-bit integer
     case ZCL_INT32S_ATTRIBUTE_TYPE: // Signed 32-bit integer
-        return writer.Put(tag, static_cast<int32_t>(value.int_value));
     default:
-        return writer.Put(tag, static_cast<int64_t>(value.int_value));
+        return writer.Put(tag, value.int_value);
     }
 }