From 807a20a152cbebcc70ab81de825a28da94a07ab6 Mon Sep 17 00:00:00 2001
From: AdityaK appujee@google.com Date: Thu, 23 Mar 2023 15:30:15 -0700 Subject: [PATCH] [PATCH] linker_lists.h: Adding comments to clarify attribute(used)
Change-Id: I2878f458b8955cac23acd54f4cfaafe7f132935b
Signed-off-by: AdityaK appujee@google.com
Tom Rini suggested we add comments because it may be confusing to have both attribute(used) and attribute(unused) in the same declaration.
--- include/linker_lists.h | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/include/linker_lists.h b/include/linker_lists.h index 5e95e30b5d..4e41f86eab 100644 --- a/include/linker_lists.h +++ b/include/linker_lists.h @@ -121,6 +121,14 @@ * :: * * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub); + * + * The static variable `start` gets dropped by clang compiler in optimized + * build as zero sized arrays aren't C-standards compliant. + * https://github.com/llvm/llvm-project/issues/60967 + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108915 + * Adding attribute((used)) allows the symbol to be preserved. Note that + * attribute((used)) and attribute((unused)) do not cancel each other as + * they had different semantics. */ #define ll_entry_start(_type, _list) \ ({ \ --