summaryrefslogtreecommitdiff
path: root/Documentation/CodingStyle
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/CodingStyle')
-rw-r--r--Documentation/CodingStyle13
1 files changed, 13 insertions, 0 deletions
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.