Exporting static const int data member from shared library

Exporting static const int data member from shared library

Post by Z. Majee » Fri, 03 Oct 2003 12:55:06


I'm building a C++ shared library with CodeWarrior 8.3 on Mac OS X 10.2.6.
In one class I have the equivalent of:

MyClass.h:

class MyClass {
public:
static const int mem1;
};

MyClass.cpp:

#include "MyClass.h"
const int MyClass::mem1 = 1;

The library is built with the equivalent of:

mwcc -c -fpic -g -gccinc -o MyClass.o MyClass.cpp
mwld -shared -export all -o libMyClass.lib MyClass.o

This sample contains the essence of the real code but unfortunately does not
reproduce the problem. In the sample libMyClass.lib exports MyClass::mem1.
But in the real code, MyClass::mem1 is not exported from libMyClass.lib.

In the real code, looking at the object file MyClass.o with "mwld -dis -show
only,names" I see MyClass::mem1 DEFINED, but "nm libMyClass.lib" shows the
library does not export MyClass::mem1; the symbol is also missing from the
mapfile. So I get an undefined reference error when building an app with the
shared library.

Here's the strange part: if I make mem1 non-const or change its type to
static const char, then the symbol is exported from the library and my app
links without errors.

Any ideas why a static const int data member would not be exported from a
shared library? Or how I could debug this problem; a mapfile has not helped.

By the way,the same code works on Windows, Unix, and Linux, and with gcc and
mwpefcc on Mac OS X.

Thanks,
Zartaj
 
 
 

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