-##
-## Coding conventions in the Samba 3.0 tree
-##
+Coding conventions in the Samba tree
+------------------------------------
+
+.. contents::
===========
Quick Start
===========
Coding style guidelines are about reducing the number of unnecessary
-reformatting patches and making things easier developers to work together.
+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
-described here are hopefully easier enough to follow as they are very
+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.
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
--
(Thanks to SATOH Fumiyasu <fumiyas@osstech.jp> for these hints):
-For the basic vi eitor including with all variants of *nix, add the
+For the basic vi editor including 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
-disaplaying trailing whitespace:
+displaying trailing whitespace::
if has("syntax") && (&t_Co > 2 || has("gui_running"))
syntax on
endf
autocmd BufNewFile,BufRead * call ActivateInvisibleCharIndicator()
endif
+ " Show tabs, trailing whitespace, and continued lines visually
+ set list listchars=tab:»·,trail:·,extends:…
+
+ " highlight overly long lines same as TODOs.
+ set textwidth=80
+ autocmd BufNewFile,BufRead *.c,*.h exec 'match Todo /\%>' . &textwidth . 'v.\+/'
+
+
+=========================
+FAQ & Statement Reference
+=========================
+
+Comments
+--------
+
+Comments should always use the standard C syntax. C++
+style comments are not currently allowed.
+
+
+Indention & Whitespace & 80 columns
+-----------------------------------
+
+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.
+Use tabs to get as close as possible and then fill in the final 7
+characters or less with whitespace. For example,
+
+ var1 = foo(arg1, arg2,
+ arg3);
+
+The previous example is intended to illustrate alignment of function
+parameters across lines and not as encourage for gratuitous line
+splitting. Never split a line before columns 70 - 79 unless you
+have a really good reason. Be smart about formatting.
+
+
+If, switch, & Code blocks
+-------------------------
+
+Always follow an 'if' keyword with a space but don't include additional
+spaces following or preceding the parentheses in the conditional.
+This is good:
+
+ if (x == 1)
+
+This is bad:
+
+ if ( x == 1 )
+
+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
+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.
+
+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
+loop.
+
+Good examples::
+
+ if (x == 1) {
+ printf("good\n");
+ }
+
+ for (x=1;
+ x<10;
+ x++)
+ {
+ print("%d\n", x);
+ }
+
+ do {
+ printf("also good\n");
+ } while (1);
+
+Bad examples::
+
+ while (1)
+ {
+ print("I'm in a loop!\n"); }
+
+
+Goto
+----
+
+While many people have been academically taught that goto's are fundamentally
+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;
+
+ if ( y < 10 ) {
+ z = malloc(sizeof(int)*y);
+ if (!z) {
+ ret = 1;
+ goto done;
+ }
+ }
+
+ print("Allocated %d elements.\n", y);
+
+ done:
+ if (z)
+ free(z);
+
+ 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.::
+
+ if ((x = malloc(sizeof(short)*10)) == NULL ) {
+ fprintf(stderr, "Unable to alloc memory!\n");
+ }
+
+or::
+ x = malloc(sizeof(short)*10);
+ if (!x) {
+ fprintf(stderr, "Unable to alloc memory!\n");
+ }
-===================
-Statement Reference
-===================
-To be filled later in as needed.
+Primitive Data Types
+--------------------
+Samba has large amounts of historical code which makes use of data types
+commonly supported by the C99 standard. However, at the time such types
+as boolean and exact width integers did not exist and Samba developers
+were forced to provide their own. Now that these types are guaranteed to
+be available either as part of the compiler C99 support or from lib/replace/,
+new code should adhere to the following conventions:
+ * 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
git.samba.org / jra / samba / .git / blobdiff