Re: [PATCH] Replace scripts/headers_install.pl with a shell script.

[Arnaud Lacombe]

Hi,

On Tue, Jan 18, 2011 at 9:06 AM, Rob Landley <rlandley@xxxxxxxxxxxxx> wrote:
> From: Rob Landley <rlandley@xxxxxxxxxxxxx>
>
> Remove perl from make headers_install by replacing a perl script (doing
> a simple regex search and replace) with a smaller and faster shell script
> implementation.  The new shell script is a single for loop calling sed and
> piping its output through unifdef to produce the target file.
>
> Change from last time: better error handling.  Split "sed | unifdef" into
> two stages with a temp file because dash hasn't got PIPEFAIL.  Add check
> for exit code, add trap handler to delete output when exiting prematurely.
>
> Signed-off-by: Rob Landley <rlandley@xxxxxxxxxxxxx>
> ---
>
>  scripts/Makefile.headersinst |    6 ++--
>  scripts/headers_install.pl   |   49 ---------------------------------
>  scripts/headers_install.sh   |   39 ++++++++++++++++++++++++++
>  3 files changed, 42 insertions(+), 52 deletions(-)
>
> diff -ruN linux-2.6.30.old/scripts/headers_install.sh linux-2.6.30/scripts/headers_install.sh
> --- linux-2.6.30.old/scripts/headers_install.sh 1969-12-31 18:00:00.000000000 -0600
> +++ linux-2.6.30/scripts/headers_install.sh     2009-06-22 16:21:23.000000000 -0500
> @@ -0,0 +1,42 @@
> +#!/bin/sh
> +
> +if [ $# -lt 2 ]
> +then
> +       echo "Usage: headers_install.sh INDIR OUTDIR [FILES...]
> +       echo
> +       echo "Prepares kernel header files for use by user space, by removing"
> +       echo "all compiler.h definitions and #includes, removing any"
> +       echo "#ifdef __KERNEL__ sections, and putting __underscores__ around"
> +       echo "asm/inline/volatile keywords."
> +       echo
> +       echo "INDIR:  directory to read each kernel header FILE from."
> +       echo "OUTDIR: directory to write each userspace header FILE to."
> +       echo "FILES:  list of header files to operate on."
> +
> +       exit 1
> +fi
> +
> +# Grab arguments
> +
> +INDIR="$1"
> +shift
> +OUTDIR="$1"
> +shift
> +
> +# Iterate through files listed on command line
> +
> +trap "rm -f $OUTDIR/$i $OUTDIR.sed" EXIT
> +for i in "$@"
> +do
> +       sed -r \
-r is not portable outside the GNU world.

> +               -e 's/([ \t(])(__user|__force|__iomem)[ \t]/\1/g' \
these regex are not portable either.

If this perl is to be replaced by sed, I guess it should at least be
POSIX-compliant (cf. [0]).

 - Arnaud

[0]: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/sed.html

> +               -e 's/__attribute_const__([ \t]|$)/\1/g' \
> +               -e 's@^#include <linux/compiler.h>@@' \
> +               -e 's/(^|[ \t])(inline|asm|volatile)([ \t(]|$)/\1__\2__\3/g' \
> +               "$INDIR/$i" > "$OUTDIR/$i.sed" || exit 1
> +       scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ "$OUTDIR/$i.sed" \
> +               > "$OUTDIR/$i"
> +       [ $? -gt 1 ] && exit 1
> +       rm -f "$OUTDIR/$i.sed"
> +done
> +trap - EXIT
> diff -ruN linux-2.6.30.old/scripts/Makefile.headersinst linux-2.6.30/scripts/Makefile.headersinst
> --- linux-2.6.30.old/scripts/Makefile.headersinst       2009-06-09 22:05:27.000000000 -0500
> +++ linux-2.6.30/scripts/Makefile.headersinst   2009-06-22 16:21:23.000000000 -0500
> @@ -45,8 +45,8 @@
>  quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
>                             file$(if $(word 2, $(all-files)),s))
>       cmd_install = \
> -        $(PERL) $< $(srctree)/$(obj) $(install) $(SRCARCH) $(header-y); \
> -        $(PERL) $< $(objtree)/$(obj) $(install) $(SRCARCH) $(objhdr-y); \
> +      $(CONFIG_SHELL) $< $(srctree)/$(obj) $(install) $(header-y); \
> +      $(CONFIG_SHELL) $< $(objtree)/$(obj) $(install) $(objhdr-y); \
>         touch $@
>
>  quiet_cmd_remove = REMOVE  $(unwanted)
> @@ -69,7 +69,7 @@
>        @:
>
>  targets += $(install-file)
> -$(install-file): scripts/headers_install.pl $(input-files) FORCE
> +$(install-file): scripts/headers_install.sh $(input-files) FORCE
>        $(if $(unwanted),$(call cmd,remove),)
>        $(if $(wildcard $(dir $@)),,$(shell mkdir -p $(dir $@)))
>        $(call if_changed,install)
> --- a/scripts/headers_install.pl
> +++ /dev/null
> @@ -1,57 +0,0 @@
> -#!/usr/bin/perl -w
> -#
> -# headers_install prepare the listed header files for use in
> -# user space and copy the files to their destination.
> -#
> -# Usage: headers_install.pl readdir installdir arch [files...]
> -# readdir:    dir to open files
> -# installdir: dir to install the files
> -# arch:       current architecture
> -#             arch is used to force a reinstallation when the arch
> -#             changes because kbuild then detect a command line change.
> -# files:      list of files to check
> -#
> -# Step in preparation for users space:
> -# 1) Drop all use of compiler.h definitions
> -# 2) Drop include of compiler.h
> -# 3) Drop all sections defined out by __KERNEL__ (using unifdef)
> -
> -use strict;
> -
> -my ($readdir, $installdir, $arch, @files) = @ARGV;
> -
> -my $unifdef = "scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__";
> -
> -foreach my $file (@files) {
> -       my $tmpfile = "$installdir/$file.tmp";
> -
> -       open(my $in, '<', "$readdir/$file")
> -           or die "$readdir/$file: $!\n";
> -       open(my $out, '>', $tmpfile)
> -           or die "$tmpfile: $!\n";
> -       while (my $line = <$in>) {
> -               $line =~ s/([\s(])__user\s/$1/g;
> -               $line =~ s/([\s(])__force\s/$1/g;
> -               $line =~ s/([\s(])__iomem\s/$1/g;
> -               $line =~ s/\s__attribute_const__\s/ /g;
> -               $line =~ s/\s__attribute_const__$//g;
> -               $line =~ s/^#include <linux\/compiler.h>//;
> -               $line =~ s/(^|\s)(inline)\b/$1__$2__/g;
> -               $line =~ s/(^|\s)(asm)\b(\s|[(]|$)/$1__$2__$3/g;
> -               $line =~ s/(^|\s|[(])(volatile)\b(\s|[(]|$)/$1__$2__$3/g;
> -               printf {$out} "%s", $line;
> -       }
> -       close $out;
> -       close $in;
> -
> -       system $unifdef . " $tmpfile > $installdir/$file";
> -       # unifdef will exit 0 on success, and will exit 1 when the
> -       # file was processed successfully but no changes were made,
> -       # so abort only when it's higher than that.
> -       my $e = $? >> 8;
> -       if ($e > 1) {
> -               die "$tmpfile: $!\n";
> -       }
> -       unlink $tmpfile;
> -}
> -exit 0;
> --
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