Code Conventions

Code conventions

Function naming

All functions are named accordingly : module name (in lower case) + _ + function name (in mixed case, without underscores). For instance : intf_FooFunction. Static functions don't need usage of the module name.

Variable naming

Hungarian notations are used, that means we have the following prefixes :

   * i_ for integers (sometimes l_ for long integers) ;
   * b_ for booleans ;
   * d_ for doubles (sometimes f_ for floats) ;
   * pf_ for function pointers ;
   * psz_ for a Pointer to a String terminated by a Zero (C-string) ;
   * More generally, we add a p when the variable is a pointer to a type. 

If one variable has no basic type (for instance a complex structure), don't put any prefix (except p_ if it's a pointer). After one prefix, put an explicit variable name in lower case. If several words are required, join them with an underscore (no mixed case). Examples :

   * data_packet_t * p_buffer;
   * char psz_msg_date[42];
   * int pi_es_refcount[MAX_ES];
   * void (* pf_next_data_packet)( int * );

Macro usage

static inline are preferred over macros, for example:

 static inline void change_val(int * var, int val)
 {
     *var = val;
 }

is preferred to

 #define CHANGE_VAL(var_name, val) var_name = val;

A few words about white spaces

Indentation

Never use tabs in the source (you're entitled to use them in the Makefile :-).

Use set expandtab under vim or the equivalent under emacs.

Indents are 4 spaces long.

Spaces

Put spaces before and after operators, and inside brackets. For instance :

for( i = 0; i < 12; i++, j += 42 ); 

Braces

Leave braces alone on their lines (GNU style). For instance :

if( i_es == 42 )
{
   p_buffer[0] = 0x12;
}

Comments

ANSI C-style comments /* ... */ are more commonly used for historical reasons, though C++/C99 comments are tolerated, but please don't mix both in the same file.

Qt interface added conventions

Switch statements

Case labels are on the same column as the switch

Example:

switch( p_item->i_type )
{
case blabla:
    break;
default:
    break;
}