X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2FCodingStyle;fp=Documentation%2FCodingStyle;h=f4b78eafd92a2e76e439f168fff97e1d41374b59;hb=d6a24d0640d609138a4e40a4ce9fd9fe7859e24c;hp=e55accfca276182170fddc67d929e7f5500a18cd;hpb=197175427a221fe3200f7727ea35e261727e7228;p=pandora-kernel.git

diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle
index e55accfca276..f4b78eafd92a 100644
--- a/Documentation/CodingStyle
+++ b/Documentation/CodingStyle
@@ -662,6 +662,19 @@ macros using parameters.
 	#define CONSTANT 0x4000
 	#define CONSTEXP (CONSTANT | 3)
 
+5) namespace collisions when defining local variables in macros resembling
+functions:
+
+#define FOO(x)				\
+({					\
+	typeof(x) ret;			\
+	ret = calc_ret(x);		\
+	(ret);				\
+)}
+
+ret is a common name for a local variable - __foo_ret is less likely
+to collide with an existing variable.
+
 The cpp manual deals with macros exhaustively. The gcc internals manual also
 covers RTL which is used frequently with assembly language in the kernel.