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crypto: fix chacha constants under GCC 15 - #20199
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GCC 15 added -Wunterminated-string-initialization, and both constants fill their array exactly, leaving no room for the terminator. Every build with that compiler fails, since crypto/Makefile treats warnings as errors. Neither is used as a string: they are read as sixteen bytes through U8TO32_LITTLE(). Letting the array size follow the literal keeps them readable, costs one byte each, and needs no attribute that only some compilers have. The cipher state is unchanged for both key sizes. Signed-off-by: Royyan Zahir <royzah@gmail.com>
xiaoxiang781216
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Both strings fill their array exactly, leaving no room for the terminator, so GCC 15 rejects the initialiser and crypto/ will not build. Dropping the explicit bound lets the compiler size them. Merged upstream as apache#20199; carried here until the submodule pin catches up. Signed-off-by: Royyan Zahir <royzah@gmail.com>
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Why
GCC 15 added
-Wunterminated-string-initialization. Both ChaCha constants fill their array exactly, leaving no room for the terminator, andcrypto/Makefileturns warnings into errors:Any build of https://github.com/apache/nuttx/blob/master/crypto/chachapoly.c with that compiler stops there.
How
Neither constant is a string. Both are read as sixteen bytes through
U8TO32_LITTLE(), and nothing looks past index 15. Letting the size follow the literal costs one byte each and needs no attribute that only some compilers have.__attribute__((nonstring))is narrower, but https://github.com/apache/nuttx/blob/master/include/nuttx/compiler.h has no macro for it and adding one across every compiler block is more than this warrants. Happy to go that way instead.Tested
GCC 15.3.0,
aarch64-none-elf, same file:chacha_keysetup()thenchacha_ivsetup()give a byte-identicalinput[16]at 256 and 128 bits.tools/nxstyleclean.