[Bug c++/44412] [4.6 Regression] Another bogus set-but-not-used warning

[jakub at gcc dot gnu dot org]

--- Comment #4 from jakub at gcc dot gnu dot org  2010-06-24 11:00 ---
Fixed.


-- 

jakub at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution||FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44412

[Bug c++/44412] [4.6 Regression] Another bogus set-but-not-used warning

[jakub at gcc dot gnu dot org]

--- Comment #1 from jakub at gcc dot gnu dot org  2010-06-04 12:03 ---
More complete testcase:

// PR c++/44412
// { dg-do compile }
// { dg-options -Wunused }

struct S
{
  static const int a = 3;
  static int b;
  int c;
};

const int S::a;
int S::b = 4;

int
f1 ()
{
  S s;
  return s.a;
}

int
f2 ()
{
  S s;
  return s.b;
}

void
f3 ()
{
  S s;
  s.c = 6;// { dg-warning set but not used }
}

int
f4 ()
{
  S s;
  s.c = 6;
  return s.c;
}

Guess we should mark the object through which a static data member is accessed,
because that access already marks the object as TREE_USED, yet it is not a set
of the object.  Not sure where to do that though.  Calling methods or static
methods apparently is handled already, in both cases build_new_method_call
- build_this - cp_build_unary_op ADDR_EXPR - mark_lvalue_use -
mark_exp_read takes care of it:

// PR c++/44412
// { dg-do compile }
// { dg-options -Wunused }

struct S
{
  int foo ();
  static int bar ();
};

int S::foo ()
{
  return 5;
}

int S::bar ()
{
  return 6;
}

int
f1 ()
{
  S s;
  return s.foo ();
}

int
f2 ()
{
  S s;
  return s.bar ();
}


-- 

jakub at gcc dot gnu dot org changed:

   What|Removed |Added

 CC||dodji at gcc dot gnu dot
   ||org, jason at gcc dot gnu
   ||dot org
Summary|Another bogus set-but-not-  |[4.6 Regression] Another
   |used warning|bogus set-but-not-used
   ||warning
   Target Milestone|--- |4.6.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44412

[Bug c++/44412] [4.6 Regression] Another bogus set-but-not-used warning

[jakub at gcc dot gnu dot org]

--- Comment #2 from jakub at gcc dot gnu dot org  2010-06-04 14:12 ---
Created an attachment (id=20838)
 -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20838action=view)
gcc46-pr44412.patch

Untested patch.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44412

[Bug c++/44412] [4.6 Regression] Another bogus set-but-not-used warning

[jakub at gcc dot gnu dot org]

--- Comment #3 from jakub at gcc dot gnu dot org  2010-06-04 18:46 ---
Subject: Bug 44412

Author: jakub
Date: Fri Jun  4 18:45:07 2010
New Revision: 160290

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=160290
Log:
PR c++/44412
* typeck.c (build_class_member_access_expr): Call mark_exp_read
on object for static data members.

* g++.dg/warn/Wunused-var-10.C: New test.
* g++.dg/warn/Wunused-var-11.C: New test.

Added:
trunk/gcc/testsuite/g++.dg/warn/Wunused-var-10.C
trunk/gcc/testsuite/g++.dg/warn/Wunused-var-11.C
Modified:
trunk/gcc/cp/ChangeLog
trunk/gcc/cp/typeck.c
trunk/gcc/testsuite/ChangeLog


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44412