[Qemu-devel] [PATCH v2 1/8] CODING_STYLE: Section about conditional statement

[arei.gonglei]

From: Gonglei <address@hidden>

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

Signed-off-by: Gonglei <address@hidden>
---
 CODING_STYLE | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/CODING_STYLE b/CODING_STYLE
index 4280945..11a79d4 100644
--- a/CODING_STYLE
+++ b/CODING_STYLE
@@ -91,3 +91,22 @@ 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 statement
+
+Please don't use Yoda conditions because of lack of readability. Furthermore,
+it is not the QEMU idiomatic coding style. Example:
+
+Usually a conditional statement in QEMU would be written as:
+if (a == 0) {
+    /* Reads like: "If a is equal to 0..." */
+    do_something();
+}
+
+Yoda conditions describe the same expression, but reversed:
+if (0 == a) {
+    /* Reads like: "If 0 equals to a" */
+    do_something();
+}
+
+The constant is listed first, then the variable being compared to.
-- 
1.7.12.4