1# ArkCompiler Subsystem Changelog
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3## cl.arkcompiler.1 Field __unused in the stat, shminfo, msqid_ds, icmphdr, mq_attr, and utmpx Structs Is Renamed __unused1
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5**Access Level**
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7Public API
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9**Change Reason**
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11The **__unused** field in the **stat**, **shminfo**, **msqid_ds**, **icmphdr**, **mq_attr**, and **utmpx** structs conflicts with the **__unused** macro definition in **sys/cdefs.h**. If both of them are imported, a build error is reported.
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13**Change Impact**
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15This change is a non-compatible change.
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17In API version 11 and earlier versions, the **__unused** field in the preceding structs can be used normally.
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19In API version 12 and later versions, a build error is reported when the **__unused** field in the preceding structs is used. You need to change the **__unused** field to **__unused1**.
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21**Start API Level**
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2310
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25**Change Since**
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27OpenHarmony SDK 5.0.0.22
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29**Key API/Component Changes**
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31Structs **stat**, **shminfo**, **msqid_ds**, **icmphdr**, **mq_attr**, and **utmpx**
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33**Adaptation Guide**
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35If the **__unused** field in the preceding structs is used, change it to **__unused1**.
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37If the field is not used, no adaptation is required.
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39The **__unused** macro definition in **cdefs.h** is not affected.
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