123 lines
3.4 KiB
Plaintext
123 lines
3.4 KiB
Plaintext
$NetBSD: STYLE,v 1.2 1997/04/08 00:18:25 cgd Exp $
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Style guide for NetBSD/alpha kernel files.
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This file is meant to supplement the NetBSD KNF style guide (which covers
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most of the rest of the system, and can be found in /usr/share/misc/style).
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SECTIONS
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* INCLUDE FILES
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* RCS IDS
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* COMPILATION FLAGS
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* MACRO DEFINITIONS
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* BLOCKS AND EXPRESSIONS
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INCLUDE FILES
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(1) All C and assembly sources (which are not included by other C or
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assembly sources) sources should include <machine/options.h> as the
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first header to be included, with a line like:
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#include <machine/options.h> /* Pull in config options headers */
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(2) All C sources should include <sys/cdefs.h> (after <machine/options.h>,
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when it is included, otherwise as the first header to be included), with
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a line like:
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#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
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(3) Nothing should include <sys/conf.h> directly. Instead, <machine/conf.h>
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should be included. It includes <sys/conf.h> and provides appropriate
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definitions for the machine-dependent devices and macros used by the Alpha
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port.
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RCS IDS
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(1) NetBSD RCS ID tags ($NetBSD: STYLE,v 1.2 1997/04/08 00:18:25 cgd Exp $ tags) in C sources and headers should
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appear at the top of the file in a single-line comment of the form
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/*<space>$NetBSD: STYLE,v 1.2 1997/04/08 00:18:25 cgd Exp $<space>*/
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which differs from the normal NetBSD style, in that it uses spaces
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rather than tabs to seperate the tag from the comment start and end
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delimiters.
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(2) All C and assembler sources should include an RCS ID tag which can
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be compiled into the binary, with a line like:
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__KERNEL_RCSID(0, "$NetBSD: STYLE,v 1.2 1997/04/08 00:18:25 cgd Exp $");
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after the inclusion of cdefs.h. Source files which include other source
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files should change the number '0' to a different number, so that it
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doesn't conflict with the RCS ID definitios in included sources.
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Generation of these RCS IDs is disabled if the kernel option
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NO_KERNEL_RCSIDS is defined. (In some cases, picking the number to use
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may not be so straightforward, but the rule above usually works.)
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COMPILATION FLAGS
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By default, NetBSD/alpha kernel files are compiled with the following gcc
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warning flags:
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-Werror
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-Wall
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-Wstrict-prototypes
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-Wmissing-prototypes
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-Wno-format
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NetBSD/alpha kernel code should compile cleanly with those flags. At some
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point in the future (when the nonstandard extensions have been removed
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from the kernel printf() function), -Wformat will be re-enabled, so sources
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should be able to compile with it enabled as well.
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MACRO DEFINITIONS
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(1) Macros which use C blocks (i.e. are of the form "{ ... expressions
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... }") should always be defined like:
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#define MACRO(arg1, arg2, argN) \
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do { \
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... \
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expressions \
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... \
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} while (0)
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so that they behave like functions or macros which don't use blocks (e.g.
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for the purpose of "if (foo) MACRO(); else ...").
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BLOCKS AND EXPRESSIONS
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(1) Surround blocks with { and } more often than is absolutely necessary.
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For instance:
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if (foo)
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bar();
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is acceptable, but:
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if (foo) {
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bar();
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}
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is preferred. (In contrast, NetBSD KNF says that no braces are to be
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used for control statements with zero or one statements.)
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(2) Use extra parentheses when it makes expressions clearer. For instance,
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(foo == 10 && bar == 20)
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is acceptable, but:
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((foo == 10) && (bar == 20))
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is preferred. (In contrast, NetBSD KNF says to avoid using parentheses
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except where necessary unless the expression is very confusing without
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them.)
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