[Bug c++/51299] New: [C++11] erroneous nullptr warning on dynamic cast

[Bug c++/51299] New: [C++11] erroneous nullptr warning on dynamic cast

[jarrydb at cse dot unsw.edu.au]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51299

             Bug #: 51299
           Summary: [C++11] erroneous nullptr warning on dynamic cast
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jarrydb@cse.unsw.edu.au


The below code compiled with -Wzero-as-null-pointer-constant produces an
erroneous warning on a dynamic cast.

g++ -std=gnu++11 nullcast.cpp -c -Wzero-as-null-pointer-constant
nullcast.cpp: In function ‘void foo(Base*)’:
nullcast.cpp:13:40: warning: zero as null pointer constant
[-Wzero-as-null-pointer-constant]
nullcast.cpp:13:40: warning: zero as null pointer constant
[-Wzero-as-null-pointer-constant]

class Base
{
  public:
  virtual ~Base() = default;
};

class Derived : public Base
{
};

void foo(Base *b)
{
  Derived *d = dynamic_cast<Derived*>(b);
}

gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/home/jarrydb/current/soft/install-latest/libexec/gcc/x86_64-unknown-linux-gnu/4.7.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /home/jarrydb/current/soft/src/gcc-git/configure
--prefix=/home/jarrydb/current/soft/install-latest --disable-multilib
--enable-languages=c,c++
Thread model: posix
gcc version 4.7.0 20111125 (experimental) (GCC)

[Bug c++/51299] [C++11] erroneous nullptr warning on dynamic cast

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51299

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-11-25
         AssignedTo|unassigned at gcc dot       |paolo.carlini at oracle dot
                   |gnu.org                     |com
     Ever Confirmed|0                           |1

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-11-25 02:02:41 UTC ---
On it.

[Bug c++/51299] [C++11] erroneous nullptr warning on dynamic cast

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51299

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-11-30 18:32:27 UTC ---
Fixed.

[Bug c++/51299] [C++11] erroneous nullptr warning on dynamic cast

[paolo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51299

--- Comment #2 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2011-11-30 18:31:33 UTC ---
Author: paolo
Date: Wed Nov 30 18:31:30 2011
New Revision: 181854

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181854
Log:
/cp
2011-11-30  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/51299
    * rtti.c (ifnonnull): Use nullptr_node.
    (build_dynamic_cast_1): Call cp_truthvalue_conversion instead
    of c_common_truthvalue_conversion.

/testsuite
2011-11-30  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/51299
    * g++.dg/warn/Wzero-as-null-pointer-constant-4.C: New.

Added:
    trunk/gcc/testsuite/g++.dg/warn/Wzero-as-null-pointer-constant-4.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/rtti.c
    trunk/gcc/testsuite/ChangeLog