LXR linux/kernel/gen

   1#!/bin/sh
   2# SPDX-License-Identifier: GPL-2.0
   3
   4# This script generates an archive consisting of kernel headers
   5# for CONFIG_IKHEADERS.
   6set -e
   7sfile="$(readlink -f "$0")"
   8outdir="$(pwd)"
   9tarfile=$1
  10cpio_dir=$outdir/$tarfile.tmp
  11
  12dir_list="
  13include/
  14arch/$SRCARCH/include/
  15"
  16
  17# Support incremental builds by skipping archive generation
  18# if timestamps of files being archived are not changed.
  19
  20# This block is useful for debugging the incremental builds.
  21# Uncomment it for debugging.
  22# if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
  23# else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
  24# find $all_dirs -name "*.h" | xargs ls -l > /tmp/ls-$iter
  25
  26all_dirs=
  27if [ "$building_out_of_srctree" ]; then
  28        for d in $dir_list; do
  29                all_dirs="$all_dirs $srctree/$d"
  30        done
  31fi
  32all_dirs="$all_dirs $dir_list"
  33
  34# include/generated/compile.h is ignored because it is touched even when none
  35# of the source files changed.
  36#
  37# When Kconfig regenerates include/generated/autoconf.h, its timestamp is
  38# updated, but the contents might be still the same. When any CONFIG option is
  39# changed, Kconfig touches the corresponding timestamp file include/config/*.
  40# Hence, the md5sum detects the configuration change anyway. We do not need to
  41# check include/generated/autoconf.h explicitly.
  42#
  43# Ignore them for md5 calculation to avoid pointless regeneration.
  44headers_md5="$(find $all_dirs -name "*.h"                       |
  45                grep -v "include/generated/compile.h"   |
  46                grep -v "include/generated/autoconf.h"  |
  47                xargs ls -l | md5sum | cut -d ' ' -f1)"
  48
  49# Any changes to this script will also cause a rebuild of the archive.
  50this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
  51if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
  52if [ -f kernel/kheaders.md5 ] &&
  53        [ "$(head -n 1 kernel/kheaders.md5)" = "$headers_md5" ] &&
  54        [ "$(head -n 2 kernel/kheaders.md5 | tail -n 1)" = "$this_file_md5" ] &&
  55        [ "$(tail -n 1 kernel/kheaders.md5)" = "$tarfile_md5" ]; then
  56                exit
  57fi
  58
  59echo "  GEN     $tarfile"
  60
  61rm -rf $cpio_dir
  62mkdir $cpio_dir
  63
  64if [ "$building_out_of_srctree" ]; then
  65        (
  66                cd $srctree
  67                for f in $dir_list
  68                        do find "$f" -name "*.h";
  69                done | cpio --quiet -pd $cpio_dir
  70        )
  71fi
  72
  73# The second CPIO can complain if files already exist which can happen with out
  74# of tree builds having stale headers in srctree. Just silence CPIO for now.
  75for f in $dir_list;
  76        do find "$f" -name "*.h";
  77done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
  78
  79# Remove comments except SDPX lines
  80find $cpio_dir -type f -print0 |
  81        xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
  82
  83# Create archive and try to normalize metadata for reproducibility.
  84# For compatibility with older versions of tar, files are fed to tar
  85# pre-sorted, as --sort=name might not be available.
  86find $cpio_dir -printf "./%P\n" | LC_ALL=C sort | \
  87    tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
  88    --owner=0 --group=0 --numeric-owner --no-recursion \
  89    -I $XZ -cf $tarfile -C $cpio_dir/ -T - > /dev/null
  90
  91echo $headers_md5 > kernel/kheaders.md5
  92echo "$this_file_md5" >> kernel/kheaders.md5
  93echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
  94
  95rm -rf $cpio_dir
  96