From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753414AbaJARwE (ORCPT ); Wed, 1 Oct 2014 13:52:04 -0400 Received: from casper.infradead.org ([85.118.1.10]:52183 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751763AbaJARwC (ORCPT ); Wed, 1 Oct 2014 13:52:02 -0400 Message-ID: <542C3F3B.9010400@infradead.org> Date: Wed, 01 Oct 2014 10:51:55 -0700 From: Randy Dunlap User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 MIME-Version: 1.0 To: Nicholas Mc Guire , Michal Marek CC: Christoph Hellwig , Joe Perches , LKML Subject: Re: [PATCH 1/3] handling of _shipped files References: <20141001133608.GB5560@opentech.at> In-Reply-To: <20141001133608.GB5560@opentech.at> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/01/14 06:36, Nicholas Mc Guire wrote: > > handling of _shipped files > > This adds a section on handling of _shipped files in kbuild > Makefiles and the build process. > > Signed-off-by: Nicholas Mc Guire > --- > Documentation/kbuild/makefiles.txt | 57 +++++++++++++++++++++++++++++++++++- > 1 file changed, 56 insertions(+), 1 deletion(-) > > diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt > index 764f599..d0bd91a 100644 > --- a/Documentation/kbuild/makefiles.txt > +++ b/Documentation/kbuild/makefiles.txt > @@ -19,6 +19,7 @@ This document describes the Linux kernel Makefiles. > --- 3.10 Special Rules > --- 3.11 $(CC) support functions > --- 3.12 $(LD) support functions > + --- 3.13 _shipped - generated files > > === 4 Host Program support > --- 4.1 Simple Host Program > @@ -595,6 +596,60 @@ more details, with real examples. > LDFLAGS_vmlinux += $(call ld-option, -X) > > > +--- 3.13 _shipped - generated files > + > + Some sources in the kernel are generated by tools or special > + purpose scrips so that the build process dependencies can be kept scripts > + at a resonable level. Also in cases where the translation is not reasonable > + configuration dependent but might impact build time _shipped files build time, > + may be added along with the actual sources to speed up the build > + process. > + > + For standard tools like lex and yacc the make process will actually > + generate the _shipped files (see scripts/Makefile.lib) and retain > + them by marking them .PRECIOUS so they are not removed by the clean > + targets. > + > + For non standard tools the generation of the _shipped file it self non-standard itself > + may be manually achived by building and then renaming. A makefile achieved > + target for generate the actual target file should to be provided to generate > + though and can be conditioned on an environment variable. Most examples that I see just expect the Makefile to be modified to set (or define) the variable. > + > + Example: > + ifdef GENERATE_KEYMAP > + > + $(obj)/defkeymap.c: $(obj)/%.c: $(src)/%.map > + loadkeys --mktable $< > $@ > + > + endif > + > + The _shipped file does not appear in the actual Makefile, this is > + handled by the rules found in scripts/Makefile.lib. > + > + > + cmd_shipped = cat $< > $@ > + > + $(obj)/%: $(src)/%_shipped > + $(call cmd,shipped) > + > + > + which simply will copy the target_shipped to the target > + > + If a file of a make target is found in the build directory with the > + extension _shipped make will used it, rather than generating the _shipped, make will use it rather than generating the > + respective target file from source. > + > + The build will indicate the use of the _shipped file by the SHIPPED > + quiet command in the make output. > + > + Example: > + LD drivers/scsi/aic7xxx/built-in.o > + SHIPPED drivers/scsi/aic7xxx/aic79xx_seq.h > + SHIPPED drivers/scsi/aic7xxx/aic79xx_reg.h > + CC [M] drivers/scsi/aic7xxx/aic79xx_core.o > + CC [M] drivers/scsi/aic7xxx/aic79xx_pci.o > + SHIPPED drivers/scsi/aic7xxx/aic79xx_reg_print.c > + CC [M] drivers/scsi/aic7xxx/aic79xx_reg_print.o > === 4 Host Program support > > Kbuild supports building executables on the host for use during the > @@ -1423,10 +1478,10 @@ Original version made by Michael Elizabeth Chastain, > Updates by Kai Germaschewski > Updates by Sam Ravnborg > Language QA by Jan Engelhardt > +Kbuild support for shipped files Nicholas Mc Guire > > === 11 TODO > > -- Describe how kbuild supports shipped files with _shipped. > - Generating offset header files. > - Add more variables to section 7? > > -- ~Randy