• State Not Answered
  • Locked Locked
  • Replies 7 replies
  • Subscribers 22 subscribers
  • Views 1345 views
  • Users 0 members are here
Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Literalizing the '#' character in #define

Steve Mutschler

The C51 pre-processor treats the "#" character as the "Stringize" operator. How do I override this operator when desired?

For example:

#define X mov A,#10

Expands to:
mov A,10

How can I force a literal expansion of the "#" character such that the above macor expands to:
mov A,#10

Thanks.

Parents
  • 0

    Sorry for the "Studio Tech" moniker -- that is the default name on this machine.

    The advice for using a separate ".asm" file (i.e., the A51 "macro" directive instead of "#define") is certainly a workable solution. We do have occasion to generate in-line assembler within C programs and find that a couple of simple #define statements within the ".h" header file is a bit easier to maintain when extensive assembler code is not needed.

    Regardless, it would still be useful to know if it possible to generate a "#" from within a #define macro when using the Ax51 assembler. Regarding ANSI compliance, the A51 User Manual does offer the following two caveats on page 158:
    NOTES
    The Ax51 macro assembler does not accept C escape sequences like "\n", "\r" or
    "\x0d". You need to replace these characters with hex values.

    Unlike the Cx51 compiler, multiple strings are not concatenated to a single
    string by the Ax51 macro assembler. Therefore you need to separate multiple
    items with a comma when using the Ax51 macro assembler.

    I just wish I knew what either of these restrictions meant in terms of actual code construction! As far as I can tell, the C-macro preprocessor within A51 does not expand escape sequences or "hex values" at all.

Reply
  • 0

    Sorry for the "Studio Tech" moniker -- that is the default name on this machine.

    The advice for using a separate ".asm" file (i.e., the A51 "macro" directive instead of "#define") is certainly a workable solution. We do have occasion to generate in-line assembler within C programs and find that a couple of simple #define statements within the ".h" header file is a bit easier to maintain when extensive assembler code is not needed.

    Regardless, it would still be useful to know if it possible to generate a "#" from within a #define macro when using the Ax51 assembler. Regarding ANSI compliance, the A51 User Manual does offer the following two caveats on page 158:
    NOTES
    The Ax51 macro assembler does not accept C escape sequences like "\n", "\r" or
    "\x0d". You need to replace these characters with hex values.

    Unlike the Cx51 compiler, multiple strings are not concatenated to a single
    string by the Ax51 macro assembler. Therefore you need to separate multiple
    items with a comma when using the Ax51 macro assembler.

    I just wish I knew what either of these restrictions meant in terms of actual code construction! As far as I can tell, the C-macro preprocessor within A51 does not expand escape sequences or "hex values" at all.

Children
  • 0 in reply to Steve Mutschler

    hi,

    Regardless, it would still be useful to know if it possible to generate a "#" from within a #define macro when using the Ax51 assembler.

    If you use the assembler and needs with such definitions then I suggest you to use macro. For example:

    XCOM	MACRO
	mov A,#10
	ENDM
    Now you may use macro XCOM anywhere in assembly file. And no #define needs.

    If you use C-language and need define some assembly commands which will be used somewhere then I may suggest next way:
    - define it as C-macro:
    #define XCOM(x) MOV A,x
//... somewhere in program:
#pragma ASM
XCOM(#10)
#pragma ENDASM

    Regards,
    Oleg