6 Of course, the most important aspect in any coding style is whitespace.
7 Crusty old coders who have trouble spotting the glasses on their noses
8 can tell the difference between a tab and eight spaces from a distance
9 of approximately fifteen parsecs. Many a flamewar have been fought and
12 QEMU indents are four spaces. Tabs are never used, except in Makefiles
13 where they have been irreversibly coded into the syntax.
14 Spaces of course are superior to tabs because:
16 - You have just one way to specify whitespace, not two. Ambiguity breeds
18 - The confusion surrounding 'use tabs to indent, spaces to justify' is gone.
19 - Tab indents push your code to the right, making your screen seriously
21 - Tabs will be rendered incorrectly on editors who are misconfigured not
22 to use tab stops of eight positions.
23 - Tabs are rendered badly in patches, causing off-by-one errors in almost
25 - It is the QEMU coding style.
27 Do not leave whitespace dangling off the ends of lines.
31 Lines are 80 characters; not longer.
34 - Some people like to tile their 24" screens with a 6x4 matrix of 80x24
35 xterms and use vi in all of them. The best way to punish them is to
36 let them keep doing it.
37 - Code and especially patches is much more readable if limited to a sane
38 line length. Eighty is traditional.
39 - It is the QEMU coding style.
43 Variables are lower_case_with_underscores; easy to type and read.
44 Structured type names are in CamelCase; harder to type but standing
45 out. Scalar type names are a_lower_case_beginning_with_an a or an.
46 Do not use _t suffix if you are including any headers.
50 Every indented statement is braced; even if the block contains just one
51 statement. The opening brace is on the line that contains the control
52 flow statement that introduces the new block; the closing brace is on the
53 same line as the else keyword, or on a line by itself if there is no else
61 printf("a was something else entirely.\n");
64 An exception is the opening brace for a function; for reasons of tradition
65 and clarity it comes on a line by itself:
72 Rationale: a consistent (except for functions...) bracing style reduces
73 ambiguity and avoids needless churn when lines are added or removed.
74 Furthermore, it is the QEMU coding style.