Yangyu Chen <c...@cyyself.name> writes:
> We forgot to apply DECL_EXTERNAL to __init_cpu_features_resolver decl. When
> building with LTO, the linker cannot find the
> __init_cpu_features_resolver.lto_priv* symbol, causing the link error.
>
> This patch gets this fixed by adding DECL_EXTERNAL to the decl. To avoid used
> but never defined warning for this symbol, we also mark TREE_PUBLIC to the
> decl.
> We should also mark the decl having hidden visibility. And fix the attribute
> in
> the same way for __aarch64_cpu_features identifier.
>
> Minimal steps to reproduce the bug:
>
> echo '__attribute__((target_clones("default", "aes"))) void func1() { }' > 1.c
> echo '__attribute__((target_clones("default", "aes"))) void func2() { }' > 2.c
> echo 'void func1();void func2();int main(){func1();func2();return 0;}' >
> main.c
> gcc -flto -c 1.c 2.c
> gcc -flto main.c 1.o 2.o
>
> Fixes: 0cfde688e213 ("[aarch64] Add function multiversioning support")
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.cc (dispatch_function_versions): Adding
> DECL_EXTERNAL, TREE_PUBLIC and hidden DECL_VISIBILITY to
> __init_cpu_features_resolver and __aarch64_cpu_features.
Thanks, LGTM. I've tested this locally and was about to push, but then
realised: since you've already contributed changes (great!), it probably
wouldn't be acceptable to treat it as trivial for copyright purposes.
Could you confirm that you're contributing under the DCO:
https://gcc.gnu.org/dco.html ? If so, could you repost with a
Signed-off-by?
Sorry for the administrivia.
Richard
> ---
> gcc/config/aarch64/aarch64.cc | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index 5770491b30c..2b2d5b9e390 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -20437,6 +20437,10 @@ dispatch_function_versions (tree dispatch_decl,
> tree init_fn_id = get_identifier ("__init_cpu_features_resolver");
> tree init_fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
> init_fn_id, init_fn_type);
> + DECL_EXTERNAL (init_fn_decl) = 1;
> + TREE_PUBLIC (init_fn_decl) = 1;
> + DECL_VISIBILITY (init_fn_decl) = VISIBILITY_HIDDEN;
> + DECL_VISIBILITY_SPECIFIED (init_fn_decl) = 1;
> tree arg1 = DECL_ARGUMENTS (dispatch_decl);
> tree arg2 = TREE_CHAIN (arg1);
> ifunc_cpu_init_stmt = gimple_build_call (init_fn_decl, 2, arg1, arg2);
> @@ -20456,6 +20460,9 @@ dispatch_function_versions (tree dispatch_decl,
> get_identifier ("__aarch64_cpu_features"),
> global_type);
> DECL_EXTERNAL (global_var) = 1;
> + TREE_PUBLIC (global_var) = 1;
> + DECL_VISIBILITY (global_var) = VISIBILITY_HIDDEN;
> + DECL_VISIBILITY_SPECIFIED (global_var) = 1;
> tree mask_var = create_tmp_var (long_long_unsigned_type_node);
>
> tree component_expr = build3 (COMPONENT_REF, long_long_unsigned_type_node,
