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  1. #1
    Join Date
    Dec 2001
    Posts
    391

    #IFNDEF Preprocessor problem...HELP!

    I dont get it. I'm using MS VC++ 6 and have create 2 .CPP files and a single .H header file. Both .CPP files include the header file. The header file's contents are as follows:
    ---
    #ifndef __FOGHORN__
    #define __FOGHORN__

    int x;

    #endif
    ---

    On compiling i get the error message:
    ---
    file2.obj : error LNK2005: "int x" (?x@@3HA) already defined in file1.obj
    Debug/file1.exe : fatal error LNK1169: one or more multiply defined symbols found
    ---

    It seems the #IFNDEF preprocessor directive isnt functioning. Or maybe Im thinking it supposed to do something it's not. When I use the #IFNDEF/#DEFINE as I do in the header above isnt the preprocessor supposed to "remember" the new #DEFINE across the scope of the entire compiling process for all files in the project so that when the same #include file is included in another .CPP file the contents of the #IFNDEF/#ENDIF will NOT be included affectively avoiding an "already included" linking error? Or is it only effective during the compiling of a single .CPP file then when compiling begins for another the preprocessor clears its table starting fresh?

    Is this how it works??
    Last edited by quantass; December 23rd, 2002 at 08:49 PM.

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