topic Re: externen Verweis (keine lib), missing binary operator in LPC Microcontrollers

externen Verweis (keine lib), missing binary operator

software_entwic — Fri, 16 Sep 2016 06:13:16 GMT

English:

I use an external reference to a global data in my project collection (no lib). If I want to use a #define in a #if a == x (external define) an error missing comes binary operator. What can I do about it?

Deutscher Orginaltext:

Ich benutze in meinem Projekt einen externen Verweis auf eine globale Daten Sammlung(keine lib).

Wenn ich eine #define benutzen möchte in einem

#if (a == x(externer define))

kommt ein Fehler Missing binary Operator.

Was kann ich dagegen tun?

Re: externen Verweis (keine lib), missing binary operator

Carlos_Mendoza — Wed, 26 Oct 2016 15:33:04 GMT

Hi Andreas,

The preprocessor does not know anything about types in the language, so it cannot cast the macro _ON inside the if expression. The `#if' directive will carry out all calculations in the widest integer type known to the compiler; on most machines supported by GCC this is 64 bits.

Could you give us more information on what you are trying to achieve?

Hope it helps!

Best Regards,
Carlos Mendoza
Technical Support Engineer

Re: externen Verweis (keine lib), missing binary operator

avt — Wed, 26 Oct 2016 16:13:41 GMT

C (and C++) pre-processor comparisons only works on integers, not strings. Maybe you could explain what you are trying to achieve?

Re: externen Verweis (keine lib), missing binary operator

software_entwic — Tue, 01 Nov 2016 06:34:36 GMT

the construction:

Best Regards,
Andreas Kullick

Re: externen Verweis (keine lib), missing binary operator

avt — Tue, 01 Nov 2016 09:09:16 GMT

There is no problem with what you are trying to do. For example, this (all in a single file) works as you would expect:

#define _ON 1

#define MY_VAR _ON

#if MY_VAR == _ON

#warning ON

#else

#warning OFF

#endif

So, I can only assume that you have something wrong with your #includes. In your diagram above, does your "Using" box know about the "Predefined" box above it?

Re: externen Verweis (keine lib), missing binary operator

software_entwic — Tue, 01 Nov 2016 09:56:41 GMT

In the same file it works, but I must used an external File who it is implemented. By the external reference LPCXpresso make this error, and I don't know why.

this file is one of the first includes, after the system (<string.h> ...) libs.

1) system libs

2) data types

3) this file

4) other def

But I look again the order of this includes.

Best Regards,
Andreas Kullick