| 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)
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. 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. -- This patch is available for review at http://codereview.appspot.com/8212043