On Tue, Jan 26, 2016 at 5:18 PM, Jakub Jelinek <ja...@redhat.com> wrote: > On Tue, Jan 26, 2016 at 04:21:08PM +0100, Richard Biener wrote: >> > --- gcc/c/c-decl.c.jj 2016-01-21 00:41:47.000000000 +0100 >> > +++ gcc/c/c-decl.c 2016-01-25 16:36:31.973504082 +0100 >> > @@ -10741,11 +10741,19 @@ c_write_global_declarations_1 (tree glob >> > if (TREE_CODE (decl) == FUNCTION_DECL >> > && DECL_INITIAL (decl) == 0 >> > && DECL_EXTERNAL (decl) >> > - && !TREE_PUBLIC (decl) >> > - && C_DECL_USED (decl)) >> > + && !TREE_PUBLIC (decl)) >> > { >> > - pedwarn (input_location, 0, "%q+F used but never defined", decl); >> > - TREE_NO_WARNING (decl) = 1; >> > + if (C_DECL_USED (decl)) >> > + { >> > + pedwarn (input_location, 0, "%q+F used but never defined", >> > decl); >> > + TREE_NO_WARNING (decl) = 1; >> > + } >> > + /* For -Wunused-function push the unused statics into cgraph, >> > + so that check_global_declaration emits the warning. */ >> > + else if (warn_unused_function >> > + && ! DECL_ARTIFICIAL (decl) >> > + && ! TREE_NO_WARNING (decl)) >> > + cgraph_node::get_create (decl); >> >> Err, so why not warn here directly? > > You mean check if it has a cgraph node (i.e. get instead of get_create) and > if it doesn't, warn? What I'm worried in that case is that it might have a > cgraph node created later on for whatever reason and that we'll get double > warning (from here and from cgraphunit.c (check_global_declaration)). > I can try it though.
No, simply warn and set TREE_NO_WARNING so cgraph doesn't warn again. Richard. > Jakub