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Compiler/TMS320F28033: #define in assembly ?

rjb
Intellectual 470 points

Hello,

I am working on a project which includes C as well as Assembly code.

I have a function declarations as follows

#define USE_FUNCTION 1

int function1(void);
int function2(void);

#if USE_FUNCTION
#define _FUNCTION function1
#else 
#define _FUNCTION function2
#endif

I have to call these function from assembly routines as per the definition of FUNCTION the code snippet as follows,

LCR #_FUNCTION

if I call it the following way "assembler/compiler" throws error :

The following symbols are undefined:
FUNCTION

(I have included the header file of function definition in .asm code.)
So, questions :
1. I have to use FUNCTION in C as well as Assembly, How can I successfully call FUNCTION from the assembly.

  • 0
    TI__Guru**** 244930 points

    Rahul Birari91 said:
    (I have included the header file of function definition in .asm code.)

    How do you do that?  Do you use the .cdecls directive and include the same header file as the C code?  If you do anything else, that is likely the problem.  If you do use .cdecls, then I need a test case that allows me to reproduce the same behavior.

    Thanks and regards,

    -George

  • 0 in reply to George Mock
    Intellectual 470 points

    Hi George, Yes I have used cdelcs directive to include the same header file where prototypes for function1 and function2 compile time switch is defined as in my first post.

    Also, Initially I was just using function1 from assembly and it was building successfully.

    .cdecls C,LIST ,"header.h"

  • 0 in reply to rjb
    TI__Guru 61235 points
    Rahul,

    Try this:

    #if USE_FUNCTION
    #define _FUNCTION _function1
    #else
    #define _FUNCTION _function2
    #endif

    - David
  • 0 in reply to David M. Alter
    Intellectual 470 points

    Hello David, I have tried that as well, in that case I had to change definitions of function1 and function2 and the instances of FUNCTIONS as well. For some reason it didn't work.

    Also, I noticed in assembly file when I defined 

    .define _function1, _FUNCTION

    It works, I am not sure how to include compile time conditional switches though, Any help will be appreciated.

    Thanks 

    Rahul

  • 0 in reply to rjb
    TI__Guru**** 244930 points

    I am unable to work with small pieces of code.  I need a test case which allows me to reproduce the same behavior.  Then I can probably explain what is wrong and how to fix it.

    Thanks and regards,

    -George

  • 0 in reply to George Mock
    TI__Guru 61235 points

    Rahul, George,

    I think the 'problem' is that #define (and the assembly equivalent .define) only match whole symbols, not partial symbols.  Suppose you did the following:

    #define abc 123;
    int x;
    x = abc;

    The above works.  But if you tried to do this:

    #define abc 123;
    int x;
    x = abc4;

    you get a symbol 'abc4' undefined error.  The leading underscore that Rahul uses in his assembly code is just another character, and the parser is looking to replace _FUNCTION, not FUNCTION.

    ------------------------------------

    The solution here for Rahul is to incorporate the underscore into the #define macro:

    The above works.  I tested.

    Regards,

    David

  • 0 in reply to David M. Alter
    Intellectual 470 points

    Thanks a lot David,

    I noticed it cant be used in both assembly and C. I had to define different #defines for C and assembly.

    #define USE_FUNCTION 1

int function1(void);
int function2(void);

#if USE_FUNCTION
#define FUNCTION_C function1
#else 
#define FUNCTION_C function2
#endif

#if USE_FUNCTION
#define FUNCTION_ASM _function1
#else 
#define FUNCTION_ASM _function2
#endif

    Thanks,

    Rahul

  • 0 in reply to David M. Alter
    TI__Guru 61235 points

    Note that the following will also work:

  • 0 in reply to David M. Alter
    TI__Guru 61235 points

    Rahul,

    One more thing.  I notice that your

    #if USE_FUNCTION

    is not complete.  It needs to be:

    #if USE_FUNCTION == 1

    If you don't use the ==, you always get function1.

    Regards,

    David

  • 0 in reply to David M. Alter
    Intellectual 470 points
    Thanks, That helped.