https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81224
--- Comment #19 from Martin Liška <marxin at gcc dot gnu.org> --- (In reply to Martin Liška from comment #18) > (In reply to Jakub Jelinek from comment #17) > > (In reply to Martin Liška from comment #16) > > > --- a/gcc/c-family/c-common.c > > > +++ b/gcc/c-family/c-common.c > > > @@ -9447,7 +9447,6 @@ handle_target_attribute (tree *node, tree name, tree > > > args, int flags, > > > && TREE_STRING_LENGTH (value) == 1 > > > && TREE_STRING_POINTER (value)[0] == '\0') > > > { > > > - warning (OPT_Wattributes, "empty string in attribute %<target%>"); > > > *no_add_attrs = true; > > > } > > > } > > > > > > That will however skip entire attribute: > > > __attribute__((target("sse4.2", "", ""))) > > > > > > Or I can do patch that will just remove empty strings in a TREE_LIST. > > > What way do you prefer? > > > > Something that doesn't change behavior. So the latter is better than the > > former, but I wonder if just some return or continue when seeing empty > > string later on isn't even easier/safer. > > Well, for this purpose, maybe the original patch can be handy: > https://patchwork.ozlabs.org/patch/794801/ ? This one works for some situations, however it's quite painful to handle it properly, for instance: $ cat /tmp/ice.C __attribute__((target("default"))) int foo() {return 99;} __attribute__((target("sse4.2",""))) int foo() {return 1;} __attribute__((target("",""))) int foo() {return 1;} int main() { return foo(); } $ ./xg++ -B. /tmp/ice.C -S -c /tmp/ice.C: In function ‘<built-in>’: /tmp/ice.C:6:5: error: No dispatcher found for the versioning attributes : int foo() {return 1;} ^~~