I need to disable linker warning 4006. This warning is for multiply defined symbols in different lib''s I have. I have them because I use a base ''common'' library in many modules. For example I use things like string manipulation, parsing, file ops etc, they are in the common.lib that is used by many other libraries. The problem occurs when I use multiple libs that all inclue common.lib For me this problem is *BAD*, I''m currently getting around 1000 warnings, it''s now at a point where I ignore all my warning output as it''s too hard finding real warnings. I''ve just turned on ''Warning''s as errors'' as a hack fix but this problem also stops me seeing compile time asserts etc as well. I REALLY wan''t to learn how to turn off certain linker warnings, like pragma''s turn of compiler warnings(mostly). All ideas appreciated... Many thanks Chris Brodie http:\\fourth.flipcode.com

Hi,
The idea is not to disable warning but to solve the problem of the redefinition. If you have a header with the functions forward declared there, then maybe you should add the extern keyword.
-- Gilad

Solve the problem... The problem is that I have libs included in lib''s included in libs. Somewhere along the linking journey there comes a point where one of the based libs gets included by to child libs and I get conflicts.

These are all classes, what do you mean about using extern with forward declaration?

Chris Brodie
http:\\fourth.flipcode.com

If they are all classes then you should do the following:
in the header of the class in the begining write:
#ifndef classname_h // or any thing like this that will distinguish classes
#define classname_h
and at the end of the class write
#endif
and if this doesn''t help you can always use in your header file
#pragma once

If you really want to disable them (may be MSVC specific) rather than fix the interdependencies, you do:

#pragma warning(disable:4006)


You can push and pop the current state of the warning disable/enable status too so that you can disable the warning only in places where you know its extraneous:

#pragma warning(push)
#pragma warning(disable:4006)
.. Do some code which creates warning you don''t want
#pragma warning(pop)


Also:

#pragma warning(once:4006)
Displays the warning, but only displays it once (rather than 1000 times)

#pragma warning(default:4006)
Sets the default behaviour for that warning.

There are other things (look in the documentation!!) - such as changing the error level of a particular warning etc

One thing you might try is to make all of your data structures static.

None of these answers have worked so far... Remember that these are linker warnings not compiler warnings. I looked up the linker doco and couldn''t find anything on warning disabling. msdn.micro* says nothing. MSDN CD says nothing...

I can''t imagine that others have never had this problem....

Chris Brodie
http:\\fourth.flipcode.com

If you have variables or class definitions (not declarations) in the header files for your common.lib, you will get this warning. Put the definitions in a .cpp file.

If you absolutely must have the definition in the header file (like when using const variables instead of #define), use something like

#ifdef common_lib
const int myVar = 5;
#else
extern const int myVar
#endif

This will only define the variable in common.lib, and in all the others, it will declare it.



Mark Fassett
Laughing Dragon Entertainment
http://www.laughing-dragon.com