X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=CodingStyle;h=b0aeb4e61dcf7452b1d3faf4eb7875eb367b5803;hb=refs%2Fheads%2Fbranch-1.5;hp=bbb492e3247f4d500cb29ce6a63c0a5d28f28d48;hpb=ede818437a16d1cf50c5e8f285593f85cd6f2513;p=sliver-openvswitch.git

diff --git a/CodingStyle b/CodingStyle
index bbb492e32..b0aeb4e61 100644
--- a/CodingStyle
+++ b/CodingStyle
@@ -156,6 +156,12 @@ parameters and their corresponding size parameters should be paired.
         ...
     }
 
+Functions that destroy an instance of a dynamically-allocated type
+should accept and ignore a null pointer argument.  Code that calls
+such a function (including the C standard library function free())
+should omit a null-pointer check.  We find that this usually makes
+code easier to read.
+
 
 FUNCTION PROTOTYPES
 
@@ -468,9 +474,8 @@ global variables.
 
 C DIALECT
 
-  Try to avoid using GCC extensions where possible.
-
-  Some C99 extensions are OK:
+  Some C99 features are OK because they are widely implemented even in
+older compilers:
 
     * Flexible array members (e.g. struct { int foo[]; }).
 
@@ -485,9 +490,8 @@ C DIALECT
       only take on the values 0 or 1, because this behavior can't be
       simulated on C89 compilers.
 
-  Don't use other C99 extensions, and especially:
-
-    * Don't use // comments.
+  Don't use other C99 features that are not widely implemented in
+older compilers:
 
     * Don't use designated initializers (e.g. don't write "struct foo
       foo = {.a = 1};" or "int a[] = {[2] = 5};").
@@ -499,3 +503,10 @@ C DIALECT
 
     * Don't put a trailing comma in an enum declaration (e.g. don't
       write "enum { x = 1, };").
+
+  As a matter of style, avoid // comments.
+
+  Avoid using GCC extensions unless you also add a fallback for
+non-GCC compilers.  You can, however, use GCC extensions and C99
+features in code that compiles only on GNU/Linux (such as
+lib/netdev-linux.c), because GCC is the system compiler there.