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[Bug c++/45082] New: Static const signed int class member causes undefined symbol.
- From: "rwitmer at xmission dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 26 Jul 2010 15:25:21 -0000
- Subject: [Bug c++/45082] New: Static const signed int class member causes undefined symbol.
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
A class that has a static const signed int data member when passed to a
function as a const int& parameter will cause the data member to be an
undefined symbol. If the static const signed int data member is re-typed as
const unsigned int the error goes away. I've verified this on g++ 3.4.6 and
4.1.2. The following code example illustrates the error.
#include <stdio.h>
static const signed int GLOBAL_BUFF_SIZE=30;
class myclass
{
public:
static const int BUFF_SIZE = 20; // Causes linker error.
//static const signed int BUFF_SIZE = 20; // Causes linker error.
//static const unsigned int BUFF_SIZE = 20; // No linker error.
static const int ANOTHER_BUFF_SIZE;
int myArray[BUFF_SIZE];
/* Linker error.
% g++ static2.cpp
Undefined first referenced
symbol in file
myclass::BUFF_SIZE /var/tmp//cc2IHYwP.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status
% g++ --version
g++ (GCC) 3.4.6
and
g++ (GCC) 4.1.2
% ccppc --version
ccppc (Wind River VxWorks G++ DWARF-EH 4.1-131) 4.1.2
*/
};
// This solves the linker problem.
// Not an option for me. I need to dimension an array with BUFF_SIZE.
const int myclass::ANOTHER_BUFF_SIZE=20;
// Function that takes a constant reference to an integer.
// When a static const signed int is passed to this function
// that was defined in a class, you get the linker error.
// If that static const is declared unsigned int, you dont get the error.
// When the reference is to a global static, there is no error.
void funky(const int& in)
{
printf("What came into funky() was %d\n", in);
}
int main()
{
printf("%d\n", myclass::BUFF_SIZE); // This doesn't cause the error.
funky(myclass::BUFF_SIZE); // This line causes the error.
funky(myclass::ANOTHER_BUFF_SIZE); // This doesn't cause the error.
funky(GLOBAL_BUFF_SIZE); // This doesn't cause the error.
}
--
Summary: Static const signed int class member causes undefined
symbol.
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: rwitmer at xmission dot com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45082