[avr-libc-dev] Re: [Avr-libc-corelib] proposed corelib style guide

[Mike Perks]

Ruddick,

This is a good start. I agree with most of what you have said except the 
following:

1. We need to define what to do with functions defined via macros. 
Macros in the .h file are public by definition and macros in the .c file 
are private. Macros in c files should probably never be used and 
substituted with static functions, possibly inlined
2. There are several rules for typedefs in avr-libc. Probably the most 
consistent with what we already have is a lower case words with 
underscore and a simple suffix of _t e.g. clock_div_t

The only other question is when to use #defines, enums and const values. 
The first two are rvalues. A const value is a non-modifiable lvalue and 
the compiler may reserve storage for it e.g.

   *int const *N* = 100;*
   *int const *p = &N;    // ok*

However most people are probably not going to write this type of code. 
Defines do not have scope restrictions whereas enums and consts do.

I think we should use the simplest definitions in header files 
(#defines) and possibly some enums for a grouping of values. Inside an 
implementation then people should use enums and consts. Again enums for 
a logical grouping such as a state indicator and consts for individual 
constants such as a buffer size.

Mike Perks
Oak Micros (oakmicros.com)