-##
-## Coding conventions in the Samba 3 tree
-##
+Coding conventions in the Samba tree
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. contents::
===========
Quick Start
reformatting patches and making things easier for developers to work together.
You don't have to like them or even agree with them, but once put in place
we all have to abide by them (or vote to change them). However, coding
-style should never outweigh coding itself and so the the guidelines
+style should never outweigh coding itself and so the guidelines
described here are hopefully easy enough to follow as they are very
common and supported by tools and editors.
-The basic style, also mentioned in the SAMBA_4_0/prog_guide.txt is the
-Linux kernel coding style (See Documentation/CodingStyle in the kernel
-source tree). The closely matches what most Samba developers use already
-anyways.
+The basic style, also mentioned in prog_guide4.txt, is the Linux kernel coding
+style (See Documentation/CodingStyle in the kernel source tree). This closely
+matches what most Samba developers use already anyways, with a few exceptions as
+mentioned below.
But to save you the trouble of reading the Linux kernel style guide, here
are the highlights.
-
* Maximum Line Width is 80 Characters
The reason is not for people with low-res screens but rather sticking
to 80 columns prevents you from easily nesting more than one level of
- if statements or other code blocks. Use source/script/count_80_col.pl
+ if statements or other code blocks. Use source3/script/count_80_col.pl
to check your changes.
* Use 8 Space Tabs to Indent
No whitespace filler.
* No Trailing Whitespace
- Use source/script/strip_trail_ws.pl to clean you files before committing.
+ Use source3/script/strip_trail_ws.pl to clean you files before committing.
* Follow the K&R guidelines. We won't go throw them all here. You have
a copy of "The C Programming Language" anyways right? You can also use
- the format_indent.sh script found in source/script/ if all else fails.
+ the format_indent.sh script found in source3/script/ if all else fails.
--
(Thanks to SATOH Fumiyasu <fumiyas@osstech.jp> for these hints):
-For the basic vi editor including with all variants of *nix, add the
+For the basic vi editor included with all variants of \*nix, add the
following to $HOME/.exrc:
set tabstop=8
set shiftwidth=8
For Vim, the following settings in $HOME/.vimrc will also deal with
-displaying trailing whitespace:
+displaying trailing whitespace::
if has("syntax") && (&t_Co > 2 || has("gui_running"))
syntax on
Comments
--------
-Comments should always use the standard C syntax. I.e. /* ... */. C++
+Comments should always use the standard C syntax. C++
style comments are not currently allowed.
To avoid confusion, indentations are to be 8 character with tab (not
8 ' ' characters. When wrapping parameters for function calls,
-alignment parameter list with the first parameter on the previous line.
+align the parameter list with the first parameter on the previous line.
Use tabs to get as close as possible and then fill in the final 7
characters or less with whitespace. For example,
if ( x == 1 )
-Yes we have a lot of code that uses the second form and we are trying
+Yes we have a lot of code that uses the second form and we are trying
to clean it up without being overly intrusive.
Note that this is a rule about parentheses following keywords and not
-functions. Don't insert a space between the name and left parentheses when
+functions. Don't insert a space between the name and left parentheses when
invoking functions.
-Braces for code blocks used by for, if, switch, while, do..while, etc...
-should begin on the same line as the statement keyword and end on a line
-of their own. NOTE: Functions are different and the beginning left brace
-should begin on a line of its own.
+Braces for code blocks used by for, if, switch, while, do..while, etc.
+should begin on the same line as the statement keyword and end on a line
+of their own. You should always include braces, even if the block only
+contains one statement. NOTE: Functions are different and the beginning left
+brace should begin on a line of its own.
If the beginning statement has to be broken across lines due to length,
the beginning brace should be on a line of its own.
-The exception to the ending rule is when the closing brace is followed by
-another language keyword such as else or the closing while in a do..while
+The exception to the ending rule is when the closing brace is followed by
+another language keyword such as else or the closing while in a do..while
loop.
-Good examples:
+Good examples::
if (x == 1) {
printf("good\n");
}
- for (x=1;
- x<10;
- x++)
- {
+ for (x=1; x<10; x++) {
print("%d\n", x);
}
+ for (really_really_really_really_long_var_name=0;
+ really_really_really_really_long_var_name<10;
+ really_really_really_really_long_var_name++)
+ {
+ print("%d\n", really_really_really_really_long_var_name);
+ }
+
do {
printf("also good\n");
} while (1);
-Bad examples:
+Bad examples::
while (1)
{
print("I'm in a loop!\n"); }
-
+
+ for (x=1;
+ x<10;
+ x++)
+ {
+ print("no good\n");
+ }
+
+ if (i < 10)
+ print("I should be in braces.\n");
+
Goto
----
While many people have been academically taught that goto's are fundamentally
-evil, then can greatly enhance readability and reduce memory leaks when used
+evil, they can greatly enhance readability and reduce memory leaks when used
as the single exit point from a function. But in no Samba world what so ever
is a goto outside of a function or block of code a good idea.
-Good Examples:
-
-int function foo(int y)
-{
- int *z = NULL;
- int ret = 0;
+Good Examples::
- if ( y < 10 ) {
- z = malloc(sizeof(int)*y);
- if (!z) {
- ret = 1;
- goto done;
+ int function foo(int y)
+ {
+ int *z = NULL;
+ int ret = 0;
+
+ if (y < 10) {
+ z = malloc(sizeof(int)*y);
+ if (!z) {
+ ret = 1;
+ goto done;
+ }
}
- }
- print("Allocated %d elements.\n", y);
+ print("Allocated %d elements.\n", y);
- done:
- if (z)
- free(z);
+ done:
+ if (z)
+ free(z);
- return ret;
-}
+ return ret;
+ }
Checking Pointer Values
When invoking functions that return pointer values, either of the following
are acceptable. Use you best judgement and choose the more readable option.
-Remember that many other people will review it.
+Remember that many other people will review it.::
if ((x = malloc(sizeof(short)*10)) == NULL ) {
fprintf(stderr, "Unable to alloc memory!\n");
}
-or
+or::
x = malloc(sizeof(short)*10);
if (!x) {
* Booleans are of type "bool" (not BOOL)
* Boolean values are "true" and "false" (not True or False)
* Exact width integers are of type [u]int[8|16|32|64]_t
+
+
+Typedefs
+--------
+
+Samba tries to avoid "typedef struct { .. } x_t;", we always use
+"struct x { .. };". We know there are still those typedefs in the code,
+but for new code, please don't do that.
+
+Make use of helper variables
+----------------------------
+
+Please try to avoid passing function calls as function parameters
+in new code. This makes the code much easier to read and
+it's also easier to use the "step" command within gdb.
+
+Good Example::
+
+ char *name;
+
+ name = get_some_name();
+ if (name == NULL) {
+ ...
+ }
+
+ ret = some_function_my_name(name);
+ ...
+
+
+Bad Example::
+
+ ret = some_function_my_name(get_some_name());
+ ...
+
git.samba.org / ira / wip.git / blobdiff