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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-09-16 18:08:41 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-09-16 18:08:41 +0000
commite31cc1efd724903b9cfeca5c070978113586ed28 (patch)
tree59e1fe0085540c2dd20a2ffa171f0bb8c732f7d4 /docs
parentAdding upstream version 256. (diff)
downloadsystemd-upstream/256.1.tar.xz
systemd-upstream/256.1.zip
Adding upstream version 256.1.upstream/256.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs')
-rw-r--r--docs/CNAME1
-rw-r--r--docs/CODING_STYLE.md62
2 files changed, 49 insertions, 14 deletions
diff --git a/docs/CNAME b/docs/CNAME
new file mode 100644
index 0000000..cdcf4d9
--- /dev/null
+++ b/docs/CNAME
@@ -0,0 +1 @@
+systemd.io \ No newline at end of file
diff --git a/docs/CODING_STYLE.md b/docs/CODING_STYLE.md
index 8f687e6..309436a 100644
--- a/docs/CODING_STYLE.md
+++ b/docs/CODING_STYLE.md
@@ -164,30 +164,64 @@ SPDX-License-Identifier: LGPL-2.1-or-later
thread. Use `is_main_thread()` to detect whether the calling thread is the
main thread.
-- Do not write functions that clobber call-by-reference variables on
- failure. Use temporary variables for these cases and change the passed in
- variables only on success. The rule is: never clobber return parameters on
- failure, always initialize return parameters on success.
-
-- Typically, function parameters fit into three categories: input parameters,
- mutable objects, and call-by-reference return parameters. Input parameters
- should always carry suitable "const" declarators if they are pointers, to
- indicate they are input-only and not changed by the function. Return
- parameters are best prefixed with "ret_", to clarify they are return
- parameters. (Conversely, please do not prefix parameters that aren't
- output-only with "ret_", in particular not mutable parameters that are both
- input as well as output). Example:
+- Typically, function parameters fit into four categories: input parameters,
+ mutable objects, call-by-reference return parameters that are initialized on
+ success, and call-by-reference return parameters that are initialized on
+ failure. Input parameters should always carry suitable `const` declarators if
+ they are pointers, to indicate they are input-only and not changed by the
+ function. The name of return parameters that are initialized on success
+ should be prefixed with `ret_`, to clarify they are return parameters. The
+ name of return parameters that are initialized on failure should be prefixed
+ with `reterr_`. (Examples of such parameters: those which carry additional
+ error information, such as the row/column of parse errors or so). –
+ Conversely, please do not prefix parameters that aren't output-only with
+ `ret_` or `reterr_`, in particular not mutable parameters that are both input
+ as well as output.
+
+ Example:
```c
static int foobar_frobnicate(
Foobar* object, /* the associated mutable object */
const char *input, /* immutable input parameter */
- char **ret_frobnicated) { /* return parameter */
+ char **ret_frobnicated, /* return parameter on success */
+ unsigned *reterr_line, /* return parameter on failure */
+ unsigned *reterr_column) { /* ditto */
return 0;
}
```
+- Do not write functions that clobber call-by-reference success return
+ parameters on failure (i.e. `ret_xyz`, see above), or that clobber
+ call-by-reference failure return parameters on success
+ (i.e. `reterr_xyz`). Use temporary variables for these cases and change the
+ passed in variables only in the right condition. The rule is: never clobber
+ success return parameters on failure, always initialize success return
+ parameters on success (and the reverse for failure return parameters, of
+ course).
+
+- Please put `reterr_` return parameters in the function parameter list last,
+ and `ret_` return parameters immediately before that.
+
+ Good:
+
+ ```c
+ static int do_something(
+ const char *input,
+ const char *ret_on_success,
+ const char *reterr_on_failure);
+ ```
+
+ Not good:
+
+ ```c
+ static int do_something(
+ const char *reterr_on_failure,
+ const char *ret_on_success,
+ const char *input);
+ ```
+
- The order in which header files are included doesn't matter too
much. systemd-internal headers must not rely on an include order, so it is
safe to include them in any order possible. However, to not clutter global