| Message ID | tencent_3B38856C376AF39D099E680F3AB2E156C40A@qq.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,aarch64] Fix function multiversioning dispatcher link error with LTO | expand |
Yangyu Chen <cyy@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 get 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. > > 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 and TREE_PUBLIC to __init_cpu_features_resolver decl. Thanks for doing this. I suppose at the same time, we should also mark __aarch64_cpu_features as TREE_PUBLIC. We could also mark both of them as having hidden visibility, via: DECL_VISIBILITY (...) = VISIBILITY_HIDDEN; DECL_VISIBILITY_SPECIFIED (...) = 1; Richard > --- > gcc/config/aarch64/aarch64.cc | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc > index 5770491b30c..37123befeaf 100644 > --- a/gcc/config/aarch64/aarch64.cc > +++ b/gcc/config/aarch64/aarch64.cc > @@ -20437,6 +20437,8 @@ 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; > tree arg1 = DECL_ARGUMENTS (dispatch_decl); > tree arg2 = TREE_CHAIN (arg1); > ifunc_cpu_init_stmt = gimple_build_call (init_fn_decl, 2, arg1, arg2);
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc index 5770491b30c..37123befeaf 100644 --- a/gcc/config/aarch64/aarch64.cc +++ b/gcc/config/aarch64/aarch64.cc @@ -20437,6 +20437,8 @@ 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; tree arg1 = DECL_ARGUMENTS (dispatch_decl); tree arg2 = TREE_CHAIN (arg1); ifunc_cpu_init_stmt = gimple_build_call (init_fn_decl, 2, arg1, arg2);
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 get 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. 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 and TREE_PUBLIC to __init_cpu_features_resolver decl. --- gcc/config/aarch64/aarch64.cc | 2 ++ 1 file changed, 2 insertions(+)