net: if: Add dummy member to anonymous union in net_if_addr #90359
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jukkar
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May 23, 2025
When both CONFIG_NET_IPV6_DAD and CONFIG_NET_IPV4_ACD are disabled, the anonymous union in struct net_if_addr ends up with no members, which results in a different struct layout between C and C++. In C, an empty union has size 0, while in C++ it has size >=1, which shifts the offsets of the following fields. Add a 1-byte dummy member to the union to ensure consistent layout across both compilers. Signed-off-by: Adrian Gielniewski <adrian.gielniewski@nordicsemi.no>
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jukkar
approved these changes
May 23, 2025
rlubos
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May 26, 2025
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When both CONFIG_NET_IPV6_DAD and CONFIG_NET_IPV4_ACD are disabled, the anonymous union in struct net_if_addr ends up with no members, which results in a different struct layout between C and C++.
In C, an empty union has size 0, while in C++ it has size >=1, which shifts the offsets of the following fields.
Add a 1-byte dummy member to the union to ensure consistent layout across both compilers.