Difference between revisions of "C Coding Standard"

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[[Category:Coding Standards]]
 
[[Category:Coding Standards]]
{{UnderConstruction}}
 
 
==Language consideration==
 
==Language consideration==
 
* Avoid using assignment inside an expression.
 
* Avoid using assignment inside an expression.
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* Never use '''return''' if this is not the last instruction of a routine.
 
* Never use '''return''' if this is not the last instruction of a routine.
 
* Use '''break''' only to separate branches of a switch statement.
 
* Use '''break''' only to separate branches of a switch statement.
 +
*A declaration
 +
*::<c>extern void foo();</c>
 +
*:needs to be
 +
*::<c>extern void foo(void);</c>
 +
*:Otherwise it is not considered a prototype (for compatability with K&R) (see bug#13870).
 +
* Use <c>"%f"</c> instead of <c>"%lf"</c> specifier in <c>printf</c> and family to print <c>double</c> (see bug#13872). This does not affect <c>scanf</c> and family.
  
 
==Style==
 
==Style==

Latest revision as of 00:45, 2 August 2013

Language consideration

  • Avoid using assignment inside an expression.
  • Never use goto.
  • Never use return if this is not the last instruction of a routine.
  • Use break only to separate branches of a switch statement.
  • A declaration
    extern void foo();
    needs to be
    extern void foo(void);
    Otherwise it is not considered a prototype (for compatability with K&R) (see bug#13870).
  • Use "%f" instead of "%lf" specifier in printf and family to print double (see bug#13872). This does not affect scanf and family.

Style

  • Always use curly braces, even when there is only one instruction. Instead of
if (a) do_something();

write

if (a) {
	do_something();
}
  • Place opening brace at the same line as the condition as in
while (expr) {
	...
}
for (;;) {
	...
}

unless the expression is very long as in

if
	(very_long_expression)
{
	...
}
  • Surround else with braces as in
if (expr) {
	...
} else {
	...
}