CODING_STYLE: split out section about destructors

diff --git a/docs/CODING_STYLE.md b/docs/CODING_STYLE.md
index 2809213af5c77308a222928f71556e5c97befd89..cad7ab295852a07b9e866793cde8abfc58317257 100644 (file)
--- a/docs/CODING_STYLE.md
+++ b/docs/CODING_STYLE.md
@@ -74,14 +74,8 @@ title: Coding Style
 - structs in `PascalCase` (with exceptions, such as public API structs),
   variables and functions in `snake_case`.
 
 - structs in `PascalCase` (with exceptions, such as public API structs),
   variables and functions in `snake_case`.
 

-- The destructors always deregister the object from the next bigger
-  object, not the other way around.
-

 - To minimize strict aliasing violations, we prefer unions over casting.
 
 - To minimize strict aliasing violations, we prefer unions over casting.
 

-- For robustness reasons, destructors should be able to destruct
-  half-initialized objects, too.
-

 - Do not issue NSS requests (that includes user name and host name
   lookups) from PID 1 as this might trigger deadlocks when those
   lookups involve synchronously talking to services that we would need
 - Do not issue NSS requests (that includes user name and host name
   lookups) from PID 1 as this might trigger deadlocks when those
   lookups involve synchronously talking to services that we would need


@@ -165,23 +159,6 @@ title: Coding Style
   failure. Use temporary variables for these cases and change the
   passed in variables only on success.
 
   failure. Use temporary variables for these cases and change the
   passed in variables only on success.
 

-- When you define a destructor or `unref()` call for an object, please
-  accept a `NULL` object and simply treat this as NOP. This is similar
-  to how libc `free()` works, which accepts `NULL` pointers and becomes a
-  NOP for them. By following this scheme a lot of `if` checks can be
-  removed before invoking your destructor, which makes the code
-  substantially more readable and robust.
-
-- Related to this: when you define a destructor or `unref()` call for an
-  object, please make it return the same type it takes and always
-  return `NULL` from it. This allows writing code like this:
-
-  ```c
-  p = foobar_unref(p);
-  ```
-
-  which will always work regardless if `p` is initialized or not, and
-  guarantees that `p` is `NULL` afterwards, all in just one line.

 
 - Instead of using `memzero()`/`memset()` to initialize structs allocated
   on the stack, please try to use c99 structure initializers. It's
 
 - Instead of using `memzero()`/`memset()` to initialize structs allocated
   on the stack, please try to use c99 structure initializers. It's


@@ -314,6 +291,31 @@ title: Coding Style
   expansion. When doing the reverse, make sure to escape `%` in specifier-style
   first (i.e. `%` → `%%`), and then do C-style escaping where necessary.
 
   expansion. When doing the reverse, make sure to escape `%` in specifier-style
   first (i.e. `%` → `%%`), and then do C-style escaping where necessary.
 

+## Destructors
+
+- The destructors always deregister the object from the next bigger object, not
+  the other way around.
+
+- For robustness reasons, destructors should be able to destruct
+  half-initialized objects, too.
+
+- When you define a destructor or `unref()` call for an object, please accept a
+  `NULL` object and simply treat this as NOP. This is similar to how libc
+  `free()` works, which accepts `NULL` pointers and becomes a NOP for them. By
+  following this scheme a lot of `if` checks can be removed before invoking
+  your destructor, which makes the code substantially more readable and robust.
+
+- Related to this: when you define a destructor or `unref()` call for an
+  object, please make it return the same type it takes and always return `NULL`
+  from it. This allows writing code like this:
+
+  ```c
+  p = foobar_unref(p);
+  ```
+
+  which will always work regardless if `p` is initialized or not,x and
+  guarantees that `p` is `NULL` afterwards, all in just one line.
+

 ## Error Handling
 
 - Error codes are returned as negative `Exxx`. e.g. `return -EINVAL`. There are
 ## Error Handling
 
 - Error codes are returned as negative `Exxx`. e.g. `return -EINVAL`. There are