On Sun, Mar 31, 2013 at 1:36 AM, Andrew Pinski <pins...@gmail.com> wrote: > On Sun, Mar 31, 2013 at 12:10 AM, Teresa Johnson <tejohn...@google.com> wrote: >> This patch allows the unused attribute to be used without warning >> on C++ class members, which are of type FIELD_DECL. This is for >> compatibility with clang, which allows the attribute to be specified on >> class members and struct fields. It looks like more work would need to >> be done to implement the actual unused variable detection and warning >> on FIELD_DECLs, but this change will at least avoid the warning on the >> code that uses the unused attribute in these cases. The documentation at >> http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html also doesn't >> seem to preclude its use on C++ member variables. > > This also allows it on field in normal C case. As far as I understand > they are fields and not variables in the normal programming sense > which is why the document does not mention them.
That's true that this change will also allow the unused attribute on normal C struct fields. I just verified that clang also allows this, and it could potentially be taken advantage of to warn on unused fields as well. Teresa > > Thanks, > Andrew Pinski > > >> >> Bootstrapped and tested on x86-64-unknown-linux-gnu. Ok for trunk? >> >> 2013-03-30 Teresa Johnson <tejohn...@google.com> >> >> * c-family/c-common.c (handle_unused_attribute): Handle >> FIELD_DECL for C++ class members. >> >> Index: c-family/c-common.c >> =================================================================== >> --- c-family/c-common.c (revision 197266) >> +++ c-family/c-common.c (working copy) >> @@ -6753,6 +6753,7 @@ handle_unused_attribute (tree *node, tree name, tr >> >> if (TREE_CODE (decl) == PARM_DECL >> || TREE_CODE (decl) == VAR_DECL >> + || TREE_CODE (decl) == FIELD_DECL >> || TREE_CODE (decl) == FUNCTION_DECL >> || TREE_CODE (decl) == LABEL_DECL >> || TREE_CODE (decl) == TYPE_DECL) >> >> -- >> This patch is available for review at http://codereview.appspot.com/8212043 -- Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
