[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
--- Comment #3 from dodji at gcc dot gnu dot org 2010-05-17 12:30 --- Created an attachment (id=20678) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20678action=view) Candidate patch On Fri, May 14, 2010 at 07:25:18AM -, jakub at gcc dot gnu dot org wrote: That said, it would be good to find out why we don't warn in that case; for [M_CONST + 6] we do warn. I think we don't warn in that case because M_CONST in the expression M_CONST + 6, M_CONST is an rvalue use and we recognize it as such via default_conversion that should be called on the arguments of the + expression. We fail to recognize the use of [M_CONST], because M_CONST gets folded into it's value without us marking that folding as an rvalue use. I am thus testing the attached patch. The reason why the patch seems convoluted is that I don't want to mark a dependant value as a rvalue use. I believe only full instantiations should be marked. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
--- Comment #4 from dodji at gcc dot gnu dot org 2010-05-17 13:54 --- Created an attachment (id=20681) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20681action=view) Don't warn for integral constants Jakub, this one line patch implements the first idea which is to not warn for integral constants, as far as Wunused_but_set_variable is concerned. I have tested it only for the reported error case. I haven't regtested it yet. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
--- Comment #5 from jakub at gcc dot gnu dot org 2010-05-17 17:25 --- Subject: Bug 44108 Author: jakub Date: Mon May 17 17:24:32 2010 New Revision: 159497 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=159497 Log: PR c++/44108 * decl.c (compute_array_index_type): Call mark_rvalue_use. * c-c++-common/Wunused-var-8.c: New test. Added: trunk/gcc/testsuite/c-c++-common/Wunused-var-8.c Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/decl.c trunk/gcc/testsuite/ChangeLog -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
--- Comment #6 from dodji at gcc dot gnu dot org 2010-05-17 19:45 --- This should be fixed in trunk (4.6) -- dodji at gcc dot gnu dot org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
-- dodji at gcc dot gnu dot org changed: What|Removed |Added AssignedTo|unassigned at gcc dot gnu |dodji at gcc dot gnu dot org |dot org | Status|UNCONFIRMED |ASSIGNED Ever Confirmed|0 |1 Last reconfirmed|-00-00 00:00:00 |2010-05-14 06:42:26 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
--- Comment #2 from jakub at gcc dot gnu dot org 2010-05-14 07:25 --- Perhaps we just shouldn't ever warn for TREE_CONSTANT decls with -Wunused-but-set-* ? Such variables can't be ever set (the set is just the definition), therefore all sets of TREE_USED for them are reads. That said, it would be good to find out why we don't warn in that case; for [M_CONST + 6] we do warn. Or for DECL_INTEGRAL_CONSTANT_VAR_P decls, or for decls for which integral_constant_value (decl) != decl not sure what is best. In any case, compute_array_index_type (and probably many other spots) calls integral_constant_value and thus doesn't see the passed in decl anymore afterwards. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
--- Comment #1 from rubidium at openttd dot org 2010-05-13 11:04 --- Created an attachment (id=20655) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20655action=view) Simple testcase Compile with g++ -Wunused-but-set-variable testcase.cpp -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
[Bug c++/44108] [4.6 Regression] -Wunused-but-set-variable does not consider array sizing use of a const variable
-- rguenth at gcc dot gnu dot org changed: What|Removed |Added Target Milestone|--- |4.6.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44108
