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Re: Need help fixing a "previously defined" error

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On 04/08/2017 02:04 PM, Peabody wrote:
> Barry Schwarz says...
> 
>  > The above conditional compilation is LCC's way of
>  > acknowledging that everything in that block is an
>  > extension to the language as defined by the standard.
>  > If you need any of those extensions, then you do not
>  > define the macro __ANSI__ONLY__.  If you don't want the
>  > LCC extensions, then you do define that macro.
...
> Doesn't it also raise the question of whether just defining
> the macro might cause the program to behave differently even
> if it successfully compiles?

Yes. That macro has a well-defined meaning for LCC - in principle, it
might have a completely different meaning (or none at all) when using
any other compiler (though with this particular name, it's unlikely to
do something completely different). Therefore, don't #define the macro
unless you first check the LCC documentation to verify what it means.

In general, turning ON C compliance should not be something done in your
code. My experience with other compilers (I have none with LCC itself)
suggests that LCC might automatically #define __ANSI_ONLY__ if you
choose the right command line option, so you don't need to #define it
yourself. Read the documentation for LCC to find out. -ansi is a popular
name for an option that turns on ANSI conformance.

> ...  In other words, if TI had
> included the macro originally, would the code still work the
> way it does?

It's quite likely that TI used a compiler that either didn't pay any
attention to __ANSI_ONLY__, or which automatically pre-#defines it when
appropriate options are selected. Either way, explicitly #defining it
would probably not have had an affect on the compiler they were using.


> ... I guess I don't understand whether ANSIC__ONLY
> just limits the functions that can be called, or whether it
> changes behavior (like long vs int as you described).

The only way to be sure is to read the LCC documentation. It's not a
general feature of C, it's compiler-specific.

> Anyway, the idea is that by defining the macro, I can
> otherwise leave TI's code the way it is, and leave LCC's
> string.h the way it is, but eliminate the error.

That would work, but I recommend removing the spurious declaration
instead. If it isn't actually being used, removing it is harmless. If it
is being used, removing it is a quick and simple way of finding out
where it's being used - doing so will almost certainly trigger an error
message if it is, in fact, being used.

...
>  > The bottom line is merely getting a clean compile should
>  > be only the first step before attempting any
>  > modifications.  You also need to verify that the newly
>  > compiled program behaves reasonably similar to the
>  > original program.
> 
> The program does lots of different things, and I don't
> really have a way to test all of them because I don't have
> the chips they apply to.

You only need to test the parts you plan to use.

> ...  Actually, I don't even understand
> all of them.  So you're saying that I would have to find the
> same version of Visual C that was used originally, which I
> don't think I know unless it's in the exe somewhere, to be
> sure that it behaves the same.

That would help, if it's easy to arrange. If not, you'll just have to
try it and see whether it works as intended.

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Thread

Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-08 08:07 -0500
  Re: Need help fixing a "previously defined" error James Kuyper <jameskuyper@verizon.net> - 2017-04-08 10:47 -0400
    Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-08 12:51 -0500
      Re: Need help fixing a "previously defined" error Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-08 20:03 +0100
      Re: Need help fixing a "previously defined" error Spiros Bousbouras <spibou@gmail.com> - 2017-04-08 19:06 +0000
      Re: Need help fixing a "previously defined" error James Kuyper <jameskuyper@verizon.net> - 2017-04-08 15:17 -0400
  Re: Need help fixing a "previously defined" error Spiros Bousbouras <spibou@gmail.com> - 2017-04-08 15:29 +0000
  Re: Need help fixing a "previously defined" error Barry Schwarz <schwarzb@dqel.com> - 2017-04-08 09:21 -0700
    Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-08 13:04 -0500
      Re: Need help fixing a "previously defined" error James Kuyper <jameskuyper@verizon.net> - 2017-04-08 15:33 -0400
        Re: Need help fixing a "previously defined" error Spiros Bousbouras <spibou@gmail.com> - 2017-04-08 19:51 +0000
        Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-08 16:24 -0500
    Re: Need help fixing a "previously defined" error Keith Thompson <kst-u@mib.org> - 2017-04-08 18:45 -0700
  Re: Need help fixing a "previously defined" error bartc <bc@freeuk.com> - 2017-04-08 17:46 +0100
    Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-08 13:19 -0500
  Re: Need help fixing a "previously defined" error David Brown <david.brown@hesbynett.no> - 2017-04-09 12:38 +0200
    Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-09 07:52 -0500
      Re: Need help fixing a "previously defined" error David Brown <david.brown@hesbynett.no> - 2017-04-09 17:02 +0200
        Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-09 18:20 -0500
          Re: Need help fixing a "previously defined" error James Kuyper <jameskuyper@verizon.net> - 2017-04-09 22:06 -0400
          Re: Need help fixing a "previously defined" error David Brown <david.brown@hesbynett.no> - 2017-04-10 09:07 +0200
            Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-10 09:11 -0500
              Re: Need help fixing a "previously defined" error David Brown <david.brown@hesbynett.no> - 2017-04-10 17:31 +0200
                Re: Need help fixing a "previously defined" error Peabody <waybackNO584SPAM44@yahoo.com> - 2017-04-10 12:48 -0500

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