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-rw-r--r--Documentation/CodingStyle27
1 files changed, 22 insertions, 5 deletions
diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle
index 9f28b14..618a33c 100644
--- a/Documentation/CodingStyle
+++ b/Documentation/CodingStyle
@@ -392,7 +392,12 @@ The goto statement comes in handy when a function exits from multiple
locations and some common work such as cleanup has to be done. If there is no
cleanup needed then just return directly.
-The rationale is:
+Choose label names which say what the goto does or why the goto exists. An
+example of a good name could be "out_buffer:" if the goto frees "buffer". Avoid
+using GW-BASIC names like "err1:" and "err2:". Also don't name them after the
+goto location like "err_kmalloc_failed:"
+
+The rationale for using gotos is:
- unconditional statements are easier to understand and follow
- nesting is reduced
@@ -403,9 +408,10 @@ The rationale is:
int fun(int a)
{
int result = 0;
- char *buffer = kmalloc(SIZE);
+ char *buffer;
- if (buffer == NULL)
+ buffer = kmalloc(SIZE, GFP_KERNEL);
+ if (!buffer)
return -ENOMEM;
if (condition1) {
@@ -413,14 +419,25 @@ int fun(int a)
...
}
result = 1;
- goto out;
+ goto out_buffer;
}
...
-out:
+out_buffer:
kfree(buffer);
return result;
}
+A common type of bug to be aware of it "one err bugs" which look like this:
+
+err:
+ kfree(foo->bar);
+ kfree(foo);
+ return ret;
+
+The bug in this code is that on some exit paths "foo" is NULL. Normally the
+fix for this is to split it up into two error labels "err_bar:" and "err_foo:".
+
+
Chapter 8: Commenting
Comments are good, but there is also a danger of over-commenting. NEVER
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