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-   -   variable problem (http://www.programmingforums.org/showthread.php?t=3302)

robert_sun Apr 12th, 2005 2:49 AM

variable problem
 
Can anybody help me on this problem:

I am writing a simulation program with several files. In a header file, I declared e global variable in hope that all other files could use it. so i put down: #define size 100 int memory[size]; in the header file memory.h. However, there are two seperate C files using that variable: simulation.c and processor.c. When I run the program, simulation.c did load all the stuff in the variable memory[size]; but when the program reaches to functions from processor.c, all the loaded stuff in variable memory[size] lost, as if the function in processor.c actually reinitialised the variable. I checked everywhere in processor.c, don't see anywhere the function can initialise the variable. I also tryed to add 'extern' in front of the definition, but end up with compiling error:
Error: Unresolved external '_memory' referenced from C:\DOCUMENTS AND SETTINGS\RS1249\CBPROJECT\SIMULATOR\WINDOWS\DEBUG_BUILD\SIMULATOR.OBJ

I don't know what to do now. Please can somebody help me on this. Thanks

brkstf Apr 12th, 2005 2:10 PM

define statements only tell the pre-processor to substitute one text string for another. you have declared it wrong.

to make something truly global, declare it BEFORE main, outside of any braces. and declare it in your driver/application file, not a library.

it's a bad idea, though. it's best to just pass the address through a function call.


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