From 344b6c0a7514b044ed12b8ad3cdeecd262292f3e Mon Sep 17 00:00:00 2001 From: Andrea Righi Date: Tue, 15 Aug 2023 08:53:46 +0200 Subject: rust: fix bindgen build error with fstrict-flex-arrays Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") enabled '-fstrict-flex-arrays=3' globally, but bindgen does not recognized this compiler option, triggering the following build error: error: unknown argument: '-fstrict-flex-arrays=3', err: true [ Miguel: Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") did it so only conditionally (i.e. only if the C compiler supports it). This explains what Andrea was seeing: he was compiling with a modern enough GCC, which enables the option, but with an old enough Clang. Andrea confirmed this was the case: he was using Clang 14 with GCC 13; and that Clang 15 worked for him. While it is possible to construct code (see mailing list for an example I came up with) where this could break, it is fairly contrived, and anyway GCC-built kernels with Rust enabled should only be used for experimentation until we get support for `rustc_codegen_gcc` and/or GCC Rust. So let's add this for the time being in case it helps somebody. ] Add '-fstrict-flex-arrays' to the list of cflags that should be ignored by bindgen. Fixes: df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") Signed-off-by: Andrea Righi Tested-by: Gary Guo Link: https://lore.kernel.org/r/20230815065346.131387-1-andrea.righi@canonical.com Signed-off-by: Miguel Ojeda --- rust/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'rust') diff --git a/rust/Makefile b/rust/Makefile index 87958e864be02..1e78c82a18a87 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -290,6 +290,7 @@ bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \ -fno-reorder-blocks -fno-allow-store-data-races -fasan-shadow-offset=% \ -fzero-call-used-regs=% -fno-stack-clash-protection \ -fno-inline-functions-called-once -fsanitize=bounds-strict \ + -fstrict-flex-arrays=% \ --param=% --param asan-% # Derived from `scripts/Makefile.clang`. -- cgit 1.2.3-korg