docs: mention C89 syntax preferences

* docs/hacking.html.in (Code formatting): Document that // comment
and declaration-after-statement are discouraged.
* HACKING: Regenerate.

1 files changed, 6 insertions, 0 deletions

diff --git a/HACKING b/HACKING
index b2ceaa7db..686328c26 100644
--- a/HACKING
+++ b/HACKING
@@ -127,6 +127,12 @@ Note that sometimes you'll have to post-process that output further, by piping
 it through "expand -i", since some leading TABs can get through. Usually
 they're in macro definitions or strings, and should be converted anyhow.
 
+Libvirt requires a C99 compiler for various reasons. However, most of the code
+base prefers to stick to C89 syntax unless there is a compelling reason
+otherwise. For example, it is preferable to use "/* */" comments rather than
+"//". Also, when declaring local variables, the prevailing style has been to
+declare them at the beginning of a scope, rather than immediately before use.
+
 
 Curly braces
 ============