__attribute__((nonstring)) and -Wunterminated-string-initialization

[frobtech]

GCC has -Wunterminated-string-initialization and __attribute__((nonstring)) to counteract it.
The warning is included in -Wextra.

It warns for e.g. char foo[3] = "foo"; because the string will not have a '\0' terminator.
It doesn't warn for __attribute__((nonstring)) char foo[3] = "foo";.

This would be a useful feature to add to Clang.

[shafik]

Note, this is a C-ism, in C++ this is ill-formed.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Roland McGrath (frobtech)

GCC has `-Wunterminated-string-initialization` and `__attribute__((nonstring))` to counteract it. The warning is included in `-Wextra`.

It warns for e.g. char foo[3] = "foo"; because the string will not have a '\0' terminator.
It doesn't warn for __attribute__((nonstring)) char foo[3] = "foo";.

This would be a useful feature to add to Clang.

[shafik]

CC @AaronBallman

[AaronBallman]

The attribute seems to only silence the diagnostic when -Wc++-compat is not enabled: https://godbolt.org/z/97Pn8Ksab