Compile char as an unsigned char

That is the default.

Can anyone tell me how to instruct Keil to compile char's as unsigned char's by default?

translation: "Can anyone tell me how to instruct Keil to abolish following the C standard"

fat chance

Anyhow most of us use something like U8 for unsigned char, so, if extensive typing is the problem, just include

#define U8 unsigned char

Erik

Thanks for the fast replies!

The problem that I am having is actually the warning: #167-D: argument of type "char *" is incompatible with parameter of type "Uchar *"

of the otherway around:
#167-D: argument of type "Uchar *" is incompatible with parameter of type "char *"

Why am I getting these warnings if Uchar and char are the same thing?

Thanks,
Eric

Uh... because they're not...?

How did you define Uchar, and did you use the above mentioned pragma to change the default type for char?

I'm sorry, I am importing code from a project developed on another platform and for some reason I was thinking that "Uchar" was defined in Keil's libraries, but it isn't.

Anyways, here is how I have Uchar defined:

typedef unsigned char Uchar;

There is no #pragma SCH in my code anywhere that I can tell. I have searched "Find in Files" for both 'SCH' and '#pragma SCH,' nothing came up.

(So, I am still confused why I am getting the previously mentioned errors?)

Thanks,
Eric

If you are importing code and want these warnings fixed quickly use:

--diag_suppress 167

in the misc controls under C/C++ of configure flash tools

The compiler is not considering char (that is unsigned by default) the same as unsigned char. It is considering them 2 different types that just happen to be the same.

U8 and/or u8 are defined in Keil, but guess what, they are not the same as char, they are the same as unsigned char (even though char is unsigned by default)

Okay, great, thanks!

So, when I receive a warning like this, I can ignore it and things should still function correctly?

Thanks,
Eric

Sure, have I ever steered you wrong?

(I have this warnig surpressed because I like to use u8's and chars without warnings.)

One more quick question, where do I put this diag_suppress line? is it a compiler directive and goes in a C file?

Thanks,
Eric

What's a negative A? Or negative '-'?

"Unsigned chars" make no sense. Unsigned 8-bit integers, yes, but not "chars".

Use char only, and always, when you mean human-readable characters alone or in strings. Use other typedefs for integer types.

Drew, I understand you Use char only, and always, when you mean human-readable characters alone or in strings. Use other typedefs for integer types. but do see a risk in your post being misinterpreted.

so,

TO PRESERVE DATA STORAGE USE (UNSIGNED) CHAR EVERY TIME IT WILL BE ENOUGH.

Erik

in the misc controls under C/C++ of configure flash tools

i.e.

Select Flash
Select configure flash tools
Select C++
add it to the line "misc controls"

Can anyone tell me how to instruct Keil to compile char's as unsigned char's by default?

translation: "Can anyone tell me how to instruct Keil to abolish following the C standard"

It's quite delightful when the grossly opinionated show their ignorance with such panache.

Robert,

Thanks a lot for your help, that worked great.

Thanks,
Eric

It's quite delightful when the grossly opinionated show their ignorance with such panache.

Maybe not 'ignorance' but 'simplification'. Yes, there is a lot about guaranteeing sign extension and such, but nevertheless

The C standard states clearly that "signed char" is same as "char" and concluding from that that 'unsigned char' is different from 'char' does not take an Einstein.

now, explain this difference

 120   1      unsigned char Usevenx = 0x74;
 121   1      unsigned char Ueightx = 0x82;
 122   1      char sevenx = 0x74;
 123   1      char eightx = 0x82;
 124   1      U8 helper;
 125   1
 126   1      if (Ueightx > Usevenx)
 127   1      {
 128   2        helper = 7;
 129   2      }
 130   1      if (eightx > sevenx)
 131   1      {
 132   2        helper = 8;
 133   2      }
 134   1
0000 750074      R     MOV     Usevenx,#074H
                                           ; SOURCE LINE # 121
0003 750082      R     MOV     Ueightx,#082H
                                           ; SOURCE LINE # 122
0006 750074      R     MOV     sevenx,#074H
                                           ; SOURCE LINE # 123
0009 750082      R     MOV     eightx,#082H
                                           ; SOURCE LINE # 126
000C E500        R     MOV     A,Ueightx
000E D3                SETB    C
000F 9500        R     SUBB    A,Usevenx
0011 4003              JC      ?C0018
                                           ; SOURCE LINE # 127
                                           ; SOURCE LINE # 128
0013 750007      R     MOV     helper,#07H
                                           ; SOURCE LINE # 129
0016         ?C0018:
                                           ; SOURCE LINE # 130
0016 D3                SETB    C
0017 E500        R     MOV     A,sevenx
0019 6480              XRL     A,#080H
001B F8                MOV     R0,A
001C E500        R     MOV     A,eightx
001E 6480              XRL     A,#080H
0020 98                SUBB    A,R0
0021 4003              JC      ?C0019
                                           ; SOURCE LINE # 131
                                           ; SOURCE LINE # 132
0023 750008      R     MOV     helper,#08H
                                           ; SOURCE LINE # 133
0026         ?C0019:

so "char' and 'unsigned char is the same???

Erik