From: Tom Rini <trini@ti.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v3 0/16] Provide a mechanism to avoid using #ifdef everywhere
Date: Thu, 21 Mar 2013 10:38:27 -0400 [thread overview]
Message-ID: <20130321143827.GF26945@bill-the-cat> (raw)
In-Reply-To: <1361895069-7343-1-git-send-email-sjg@chromium.org>
On Tue, Feb 26, 2013 at 08:10:53AM -0800, Simon Glass wrote:
> Many parts of the U-Boot code base are sprinkled with #ifdefs. This makes
> different boards compile different versions of the source code, meaning
> that we must build all boards to check for failures. It is easy to misspell
> an #ifdef and there is not as much checking of this by the compiler. Multiple
> dependent #ifdefs are harder to do than with if..then..else. Variable
> declarations must be #idefed as well as the code that uses them, often much
> later in the file/function. #ifdef indents don't match code indents and
> have their own separate indent feature. Overall, excessive use of #idef
> hurts readability and makes the code harder to modify and refactor. For
> people coming newly into the code base, #ifdefs can be a big barrier.
>
> The use of #ifdef in U-Boot has possibly got a little out of hand. In an
> attempt to turn the tide, this series includes a patch which provides a way
> to make CONFIG macros available to C code without using the preprocessor.
> This makes it possible to use standard C conditional features such as
> if/then instead of #ifdef. A README update exhorts compliance.
OK, this is true. Looking over the series, a number of the patches are
just general fixes / improvements that don't depend on the autoconf_...
work. Lets split this out now and take them in now as they seem like
reviewable by inspection code.
For the approach itself, I'm not sure which is best here. In a lot of
cases we're trading an #ifdef for adding a level of indent to already
pretty indented code and that feels like a wash, in terms of readability
to me. We probably need to re-factor some of the code in question there
too for readability, then see about using autoconf_... type things, or
maybe something else.
--
Tom
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next prev parent reply other threads:[~2013-03-21 14:38 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-26 16:10 [U-Boot] [PATCH v3 0/16] Provide a mechanism to avoid using #ifdef everywhere Simon Glass
2013-02-26 16:10 ` [U-Boot] [PATCH v3 01/16] Implement autoconf header file Simon Glass
2013-02-26 16:10 ` [U-Boot] [PATCH v3 02/16] at91: Correct CONFIG_AUTOBOOT_PROMPT definition for pm9263 Simon Glass
2013-02-26 16:10 ` [U-Boot] [PATCH v3 03/16] net: Add prototype for update_tftp, and use autoconf Simon Glass
2013-03-20 19:40 ` Tom Rini
2013-03-20 19:57 ` Simon Glass
2013-03-20 20:30 ` Tom Rini
2013-03-21 1:47 ` Simon Glass
2013-02-26 16:10 ` [U-Boot] [PATCH v3 04/16] main: Separate out the two abortboot() functions Simon Glass
2013-02-26 16:10 ` [U-Boot] [PATCH v3 05/16] main: Move boot_delay code into its own function Simon Glass
2013-02-26 16:10 ` [U-Boot] [PATCH v3 06/16] main: Use autoconf for boot retry feature Simon Glass
2013-02-26 16:11 ` [U-Boot] [PATCH v3 07/16] main: Remove CONFIG #ifdefs from the abortboot() code Simon Glass
2013-02-26 16:11 ` [U-Boot] [PATCH v3 08/16] main: Use get/setenv_ulong() Simon Glass
2013-02-26 16:11 ` [U-Boot] [PATCH v3 09/16] main: Use autoconf for boot_delay code Simon Glass
2013-02-27 9:14 ` Joe Hershberger
2013-02-26 16:11 ` [U-Boot] [PATCH v3 10/16] main: Use autoconf for parser selection Simon Glass
2013-02-26 16:11 ` [U-Boot] [PATCH v3 11/16] main: Fix typos and checkpatch warnings in command line reading Simon Glass
2013-02-27 9:25 ` Joe Hershberger
2013-02-26 16:11 ` [U-Boot] [PATCH v3 12/16] main: Use autoconf " Simon Glass
2013-02-27 9:17 ` Joe Hershberger
2013-02-26 16:11 ` [U-Boot] [PATCH v3 13/16] main: Use autoconf in main_loop() Simon Glass
2013-02-27 9:23 ` Joe Hershberger
2013-02-26 16:11 ` [U-Boot] [PATCH v3 14/16] main: Correct header order Simon Glass
2013-02-26 16:11 ` [U-Boot] [PATCH v3 15/16] main: Add debug_parser() to avoid #ifdefs Simon Glass
2013-02-26 16:11 ` [U-Boot] [PATCH v3 16/16] main: Add debug_bootkeys " Simon Glass
2013-03-21 14:38 ` Tom Rini [this message]
2013-05-13 22:12 ` [U-Boot] [PATCH v3 0/16] Provide a mechanism to avoid using #ifdef everywhere Simon Glass
2013-05-14 21:21 ` Tom Rini
2013-05-14 21:27 ` Simon Glass
2013-05-14 22:15 ` Tom Rini
2013-05-14 22:22 ` Vadim Bendebury
2013-05-14 22:28 ` Tom Rini
2013-05-15 14:13 ` Simon Glass
2013-05-16 16:26 ` Tom Rini
2013-05-16 18:49 ` Simon Glass
2013-05-30 13:57 ` Simon Glass
2013-05-30 15:17 ` Tom Rini
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