Message ID | 20130331071036.A877C807B2@tjsboxrox.mtv.corp.google.com |
---|---|
State | New |
Headers | show |
On Sun, Mar 31, 2013 at 12:10 AM, Teresa Johnson <tejohnson@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. Thanks, Andrew Pinski > > Bootstrapped and tested on x86-64-unknown-linux-gnu. Ok for trunk? > > 2013-03-30 Teresa Johnson <tejohnson@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
On Sun, Mar 31, 2013 at 1:36 AM, Andrew Pinski <pinskia@gmail.com> wrote: > On Sun, Mar 31, 2013 at 12:10 AM, Teresa Johnson <tejohnson@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 <tejohnson@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 | tejohnson@google.com | 408-460-2413
Ping. Thanks, Teresa On Sun, Mar 31, 2013 at 9:39 AM, Teresa Johnson <tejohnson@google.com> wrote: > On Sun, Mar 31, 2013 at 1:36 AM, Andrew Pinski <pinskia@gmail.com> wrote: >> On Sun, Mar 31, 2013 at 12:10 AM, Teresa Johnson <tejohnson@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 <tejohnson@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 | tejohnson@google.com | 408-460-2413 -- Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
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)