[Bug c++/30745] New: Undefined static const

[Bug c++/30745] New: Undefined static const

[hans dot buchmann at fhso dot ch]

Compiling the code

class Class
{
 public:
   Class(const unsigned maxLine);

 private:
  static const unsigned MAX_LEN = 16;
  unsigned max;
  unsigned array[MAX_LEN];
};

Class::Class(const unsigned maxLine)
:max((maxLine<MAX_LEN)?maxLine
                      :MAX_LEN)
{
}

with the command:

g++ -Wall -O0  -fno-exceptions -c -o const-test.o const-test.cc

leaves Class::MAX_LEN undefined:

nm --demangle const-test.o
         U Class::MAX_LEN
00000028 T Class::Class(unsigned int)
00000000 T Class::Class(unsigned int)


The compiler  g++ -v

Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /var/tmp/portage/gcc-4.1.1/work/gcc-4.1.1/configure
 --prefix=/usr --bindir=/usr/i686-pc-linux-gnu/gcc-bin/4.1.1 
 --includedir=/usr/lib/gcc/i686-pc-linux-gnu/4.1.1/include 
 --datadir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1 
 --mandir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1/man 
 --infodir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1/info 
 --with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/4.1.1/include/g++-v4 
 --host=i686-pc-linux-gnu 
 --build=i686-pc-linux-gnu 
 --disable-altivec 
 --enable-nls 
 --without-included-gettext 
 --with-system-zlib 
 --disable-checking 
 --disable-werror 
 --disable-libunwind-exceptions 
 --disable-multilib 
 --disable-libmudflap 
 --disable-libssp 
 --disable-libgcj 
 --enable-languages=c,c++,fortran 
 --enable-shared --enable-threads=posix 
 --enable-__cxa_atexit 
 --enable-clocale=gnu
Thread model: posix
gcc version 4.1.1 (Gentoo 4.1.1)

Best regards

Hans Buchmann


-- 
           Summary: Undefined static const
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hans dot buchmann at fhso dot ch
 GCC build triplet:  i686-pc-linux-gnu
  GCC host triplet:  i686-pc-linux-gnu
GCC target triplet:  i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2007-02-09 14:52 -------
This is not a bug, you still need a definition of the static const variable. 
You just have a declaration.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
  GCC build triplet| i686-pc-linux-gnu          |i686-pc-linux-gnu
   GCC host triplet| i686-pc-linux-gnu          |i686-pc-linux-gnu
 GCC target triplet| i686-pc-linux-gnu          |i686-pc-linux-gnu
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[hans dot buchmann at fhso dot ch]

------- Comment #2 from hans dot buchmann at fhso dot ch  2007-02-10 12:17 -------

Inserting the line

 const unsigned Class::MAX_LEN=16;

results in the message

 const-test.cc:13: error: duplicate initialization of 'Class::MAX_LEN'

When I place the declaration outside the class the Symbol MAX_LEN is 
defined:

00000000 r MAX_LEN
00000028 T Class::Class(unsigned int)
00000000 T Class::Class(unsigned int)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2007-02-10 21:12 -------
The definition have to be not inialized if it was already initialized in the
declaration

The declaration is the one which is inside the class, the definition which is
the one which defines the memory space is the one out side of the class.

If you just declare/define the variable outside of the class, that is a
definition.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[schwab at suse dot de]

------- Comment #4 from schwab at suse dot de  2007-05-12 09:15 -------
*** Bug 31904 has been marked as a duplicate of this bug. ***


-- 

schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dennis0yang at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2007-08-23 16:34 -------
*** Bug 33161 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sylvain dot pion at sophia
                   |                            |dot inria dot fr


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[paolo dot carlini at oracle dot com]

------- Comment #6 from paolo dot carlini at oracle dot com  2008-05-19 00:10 -------
*** Bug 36261 has been marked as a duplicate of this bug. ***


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Bernd dot Donner at gmx dot
                   |                            |net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

[Bug c++/30745] Undefined static const

[schwab@linux-m68k.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30745

Andreas Schwab <schwab@linux-m68k.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rarrum at gmail dot com

--- Comment #7 from Andreas Schwab <schwab@linux-m68k.org> 2010-10-17 11:36:54 UTC ---
*** Bug 46054 has been marked as a duplicate of this bug. ***