LLD 13 and GNU ld 2.37 support -z start-stop-gc which allows garbage
collection of C identifier name sections despite the __start_/__stop_
references. Simply set the retain attribute so that GCC 11 (if
configure-time binutils is 2.36 or newer)/Clang 13 will set the
SHF_GNU_RETAIN section attribute to prevent garbage collection.
Without the patch, there are linker errors like the following with -z
start-stop-gc:
ld.lld: error: undefined symbol: __stop___cmd
>>> referenced by iw.c:418
>>> iw.o:(__handle_cmd)
Suggested-by: Fangrui Song <maskray@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Manoj Gupta <manojgupta@xxxxxxxxxx>
---
iw.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/iw.h b/iw.h
index 7f7f4fc..67aa00c 100644
--- a/iw.h
+++ b/iw.h
@@ -118,8 +118,9 @@ struct chandef {
.parent = _section, \
.selector = (_sel), \
}; \
+ _Pragma("GCC diagnostic ignored \"-Wattributes\"") \
static struct cmd *__cmd ## _ ## _symname ## _ ## _handler ## _ ## _nlcmd ## _ ## _idby ## _ ## _hidden ## _p \
- __attribute__((used,section("__cmd"))) = \
+ __attribute__((used,retain,section("__cmd"))) = \
&__cmd ## _ ## _symname ## _ ## _handler ## _ ## _nlcmd ## _ ## _idby ## _ ## _hidden
#define __ACMD(_section, _symname, _name, _args, _nlcmd, _flags, _hidden, _idby, _handler, _help, _sel, _alias)\
__COMMAND(_section, _symname, _name, _args, _nlcmd, _flags, _hidden, _idby, _handler, _help, _sel);\
--
2.31.1.498.g6c1eba8ee3d-goog
