From: Gonglei <arei.gonglei@huawei.com>
Date: Mon, 11 Aug 2014 13:00:51 +0000 (+0800)
Subject: CODING_STYLE: Section about conditional statement
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2bb0020cf97c938f8339c76fa8a0da6353e8d27e;p=qemu.git

CODING_STYLE: Section about conditional statement

Yoda conditions lack readability, and QEMU has a
strict compiler configuration for checking a common
mistake like "if (dev = NULL)". Make it a written rule.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
---

diff --git a/CODING_STYLE b/CODING_STYLE
index 4280945ff0..d46cfa5f65 100644
--- a/CODING_STYLE
+++ b/CODING_STYLE
@@ -91,3 +91,17 @@ Mixed declarations (interleaving statements and declarations within blocks)
 are not allowed; declarations should be at the beginning of blocks.  In other
 words, the code should not generate warnings if using GCC's
 -Wdeclaration-after-statement option.
+
+6. Conditional statements
+
+When comparing a variable for (in)equality with a constant, list the
+constant on the right, as in:
+
+if (a == 1) {
+    /* Reads like: "If a equals 1" */
+    do_something();
+}
+
+Rationale: Yoda conditions (as in 'if (1 == a)') are awkward to read.
+Besides, good compilers already warn users when '==' is mis-typed as '=',
+even when the constant is on the right.