"Symbol Defined More Than Once" LINKing Basic 7.10/FORTRAN 5.0 (68590)

SUMMARY

Below is an example where linking Basic PDS 7.10 with FORTRAN 5.00 gives several "Symbol defined more than once" errors. In this specific case, the problem can be worked around by compiling with BC /O (the stand-alone .EXE option, using BCL71ENR.LIB).

IMPORTANT NOTE: Linking Microsoft Basic Professional Development System (PDS) 7.10 with Microsoft FORTRAN 5.00 requires first changing the FORTRAN library and including a Microsoft C 6.00 library, as explained in a separate application note, "How to Link Basic PDS 7.10 with C 5.10, FORTRAN 5.00, or Pascal 4.00." To find this application note in a separate article in this knowledge base, search for the words shown in the title of the application note, or BB0345. Despite using the steps in the application note, linking certain Basic 7.10 and FORTRAN 5.00 programs may generate the "Symbol defined more than once" errors described in the example below.

Although the methods in the application note have been designed to produce compatible results, we have not put the methods through a standard Microsoft mixed-language testing cycle, and it is possible that you may still encounter compatibility problems under certain conditions. We cannot guarantee the complete success of mixed- language programming of Basic PDS 7.10 with C 5.10, FORTRAN 5.00, or Pascal 4.00. Further problems or questions can be directed to Microsoft Language Support Services. To duplicate the problem, create the following code:

Basic.BAS

REM *********************Basic CODE*****************************
DIM x%(2048)
COMMON SHARED /nmalloc/ x%()
DECLARE SUB Test()
CALL Test
END
				

FORTRAN.FOR

C  *********************FORTRAN CODE***************************
SUBROUTINE Test
REAL frq(1)
WRITE(6,*)wreal
i=INT(frq(i))
RETURN
END
				

Compile and link with the following commands:

(NOTE: To create MIXED.LIB, you must obtain the application note "How to Link Basic PDS 7.10 with C 5.10, FORTRAN 5.00, or Pascal 4.00.")

BC /E /FPi /Zi basic.bas;
fl /c /4Yb /FPi /Zi fortran.for
link /NOD/NOE/CO basic.obj + fortran.obj,s.exe,,brt71enr.lib+
llibcer.lib+mixed.lib;
				

LINK.EXE generates the following errors: To work around this problem, add /O to the Basic compiler command line and then relink, as follows:

BC /O /E /FPi /Zi basic.bas;
link /NOD/NOE/CO basic.obj + fortran.obj,s.exe,,BCL71ENR.LIB+
llibcer.lib+mixed.lib;