[PATCH v05 02/72] scripts/headers_compile_test.sh: compile test script for exported headers

[Mikko Rapeli <mikko.rapeli@iki.fi>]

Users of kernel header files would be happier if they did not contain
kernel specific parts and would contain #include statements for all
other header files that they depend on, and in general would compile.

For each header file exported to userspace, this script tries to compile it
together with minimal header files from GCC and libc, and reports results.

Kernel headers depend on GCC headers so their path is included in the
test compiler command line.

Default libc and GCC header file locations are parsed from compiler
configuration.

Some gcc and kernel headers depend on libc headers which are made available
by copying from the compiler default location to a temporary location and
removing possibly existing kernel headers from this directory. This is a bit
of a hack but seems to work in multiple environments.

Tested natively on:

Debian unstable, i586-linux-gnu and gcc 4.9.2
Raspbian Wheezy, arm-linux-gnueabihf and gcc 4.6.3
Ubuntu 12.04 LTS, x86_64-linux-gnu and gcc 4.6.3

Tested cross compilation using standard CROSS_COMPILE=/path/to/gcc with:

arm-linux-gnueabihf-gcc (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) 4.9.2 20140904 (prerelease)

Execute the script in the directory where kernel header files are installed.
For example:

$ make headers_install
$ cd usr/include
$ ../../scripts/headers_compile_test.sh

Example statistics from v4.4-rc3-10-gc846b17 kernel on 32bit x86:

122 files failed the compile test.
645 files passed the compile test.

Example error types from v4.4-rc3-10-gc846b17 kernel:

$ ../../scripts/headers_compile_test.sh 2>&1 | \
grep error: | sed -e 's/.*error://g' | sort | uniq -c | sort -rn

    381  unknown type name ‘uint32_t’
    125  unknown type name ‘uint64_t’
     99  unknown type name ‘size_t’
     43  unknown type name ‘__kernel_ulong_t’
     29  unknown type name ‘uint8_t’
     23  unknown type name ‘int32_t’
     16  unknown type name ‘__kernel_time_t’
     14  unknown type name ‘__be16’
     14  ‘IFNAMSIZ’ undeclared here (not in a function)
     14  field ‘addr’ has incomplete type
      9  field ‘ifru_netmask’ has incomplete type
      9  field ‘ifru_hwaddr’ has incomplete type
      9  field ‘ifru_dstaddr’ has incomplete type
      9  field ‘ifru_broadaddr’ has incomplete type
      9  field ‘ifru_addr’ has incomplete type
      8  unknown type name ‘uint16_t’
      8  unknown type name ‘pid_t’
      8  unknown type name ‘__kernel_pid_t’
      7  unknown type name ‘u_short’
      5  unknown type name ‘__kernel_long_t’
      4  unknown type name ‘__kernel_uid32_t’
      4  unknown type name ‘__kernel_gid32_t’
      4  ‘ETH_ALEN’ undeclared here (not in a function)
      3  unknown type name ‘caddr_t’
      3  ‘IPSET_ERR_TYPE_SPECIFIC’ undeclared here (not in a function)
      3  field ‘src_addr’ has incomplete type
      3  field ‘laddr’ has incomplete type
      3  field ‘bssid’ has incomplete type
      3  expected specifier-qualifier-list before ‘uint64_t’
      2  unknown type name ‘u_long’
      2  unknown type name ‘stack_t’
      2  unknown type name ‘sigset_t’
      2  unknown type name ‘sa_family_t’
      2  unknown type name ‘__kernel_mode_t’
      2  unknown type name ‘__kernel_key_t’
      2  unknown type name ‘elf_gregset_t’
      2  unknown type name ‘bool’
      2  ‘uint64_t’ undeclared here (not in a function)
      2  ‘true’ undeclared (first use in this function)
      2  ‘NAME_MAX’ undeclared here (not in a function)
      2  ‘__kernel_mode_t’ undeclared here (not in a function)
      2  invalid application of ‘sizeof’ to incomplete type ‘struct sockaddr’
      2  field ‘uc_mcontext’ has incomplete type
      2  field ‘src’ has incomplete type
      2  field ‘shm_perm’ has incomplete type
      2  field ‘sem_perm’ has incomplete type
      2  field ‘raddr’ has incomplete type
      2  field ‘msg_perm’ has incomplete type
      2  field ‘grp’ has incomplete type
      2  field ‘dst_addr’ has incomplete type
      2  field ‘arp_pa’ has incomplete type
      2  field ‘arp_netmask’ has incomplete type
      2  field ‘arp_ha’ has incomplete type
      2  ‘false’ undeclared (first use in this function)
      1  xen/interface/xen.h: No such file or directory
      1  via_drmclient.h: No such file or directory
      1  unknown type name ‘wait_queue_head_t’
      1  unknown type name ‘uid_t’
      1  unknown type name ‘int64_t’
      1  unknown type name ‘int16_t’
      1  unknown type name ‘ino_t’
      1  unknown type name ‘elf_greg_t’
      1  unknown type name ‘elf_fpxregset_t’
      1  unknown type name ‘elf_fpregset_t’
      1  unknown type name ‘__be32’
      1  ‘SIOCDEVPRIVATE’ undeclared here (not in a function)
      1  ‘sa_family_t’ undeclared here (not in a function)
      1  ‘NULL’ undeclared (first use in this function)
      1  ‘MSG_FIN’ undeclared here (not in a function)
      1  ‘MAX_IPOPTLEN’ undeclared here (not in a function)
      1  ‘MAX_ADDR_LEN’ undeclared here (not in a function)
      1  ‘IFHWADDRLEN’ undeclared here (not in a function)
      1  field ‘vmask’ has incomplete type
      1  field ‘vifc_rmt_addr’ has incomplete type
      1  field ‘vifc_lcl_addr’ has incomplete type
      1  field ‘vaddr’ has incomplete type
      1  field ‘uc_chain’ has incomplete type
      1  field ‘tcp’ has incomplete type
      1  field ‘sspp_addr’ has incomplete type
      1  field ‘ssp_addr’ has incomplete type
      1  field ‘src_mask’ has incomplete type
      1  field ‘spt_address’ has incomplete type
      1  field ‘spp_address’ has incomplete type
      1  field ‘spinfo_address’ has incomplete type
      1  field ‘spc_aaddr’ has incomplete type
      1  field ‘smsk’ has incomplete type
      1  field ‘sin_addr’ has incomplete type
      1  field ‘sas_obs_rto_ipaddr’ has incomplete type
      1  field ‘saddr’ has incomplete type
      1  field ‘rtmsg_src’ has incomplete type
      1  field ‘rtmsg_gateway’ has incomplete type
      1  field ‘rtmsg_dst’ has incomplete type
      1  field ‘rt_genmask’ has incomplete type
      1  field ‘rt_gateway’ has incomplete type
      1  field ‘rt_dst’ has incomplete type
      1  field ‘prefix’ has incomplete type
      1  field ‘mfcc_origin’ has incomplete type
      1  field ‘mfcc_mcastgrp’ has incomplete type
      1  field ‘mf6cc_origin’ has incomplete type
      1  field ‘mf6cc_mcastgrp’ has incomplete type
      1  field ‘mask’ has incomplete type
      1  field ‘iph’ has incomplete type
      1  field ‘ip’ has incomplete type
      1  field ‘im_src’ has incomplete type
      1  field ‘im_dst’ has incomplete type
      1  field ‘im6_src’ has incomplete type
      1  field ‘im6_dst’ has incomplete type
      1  field ‘gw’ has incomplete type
      1  field ‘dst_mask’ has incomplete type
      1  field ‘dmsk’ has incomplete type
      1  field ‘dest_addr’ has incomplete type
      1  field ‘daddr’ has incomplete type
      1  field ‘ap_addr’ has incomplete type
      1  field ‘a6’ has incomplete type
      1  field ‘a4’ has incomplete type
      1  #error "patchkey.h included directly"
      1  ‘DLM_RESNAME_MAXLEN’ undeclared here (not in a function)
      1  array type has incomplete element type ‘struct timespec’
      1  array type has incomplete element type ‘struct in6_addr’

Once all these errors have been fixed, this test should be added to
'make headers_check'.

Since I've been stubborn enough to work with this script and fixes to the
test failures for over a year, I added my self to MAINTAINERS.
I will continue to maintain this script as a hobby.

Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Gabriel Laskar <gabriel@lse.epita.fr>
---
 MAINTAINERS                     |   5 +
 scripts/headers_compile_test.sh | 198 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 203 insertions(+)
 create mode 100755 scripts/headers_compile_test.sh

diff --git a/MAINTAINERS b/MAINTAINERS
index a306795..a6fb57d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3245,6 +3245,11 @@ S:	Maintained
 F:	mm/memcontrol.c
 F:	mm/swap_cgroup.c
 
+COMPILE TEST FOR HEADER FILES EXPORTED TO USERSPACE
+M:	Mikko Rapeli <mikko.rapeli@iki.fi>
+S:	Maintained
+F:	scripts/headers_compile_test.sh
+
 CORETEMP HARDWARE MONITORING DRIVER
 M:	Fenghua Yu <fenghua.yu@intel.com>
 L:	linux-hwmon@vger.kernel.org
diff --git a/scripts/headers_compile_test.sh b/scripts/headers_compile_test.sh
new file mode 100755
index 0000000..e13f533
--- /dev/null
+++ b/scripts/headers_compile_test.sh
@@ -0,0 +1,198 @@
+#!/bin/bash
+
+help() {
+	cat << EOF_HELP
+Userspace compile test for exported kernel headers.
+
+    Copyright (C) 2015 Mikko Rapeli <mikko.rapeli@iki.fi>
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; version 2
+    of the License.
+
+Execute in root directory of exported kernel headers in Linux kernel source
+tree. Sets up gcc and libc headers without existing kernel headers to
+a temporary environment and tries to compile all exported header files
+from current directory against them. Return value is zero if all tests pass,
+non-zero if something goes wrong during execution, or the amount of files
+which failed the compile test.
+
+Supported arguments:
+
+    -h|--help       print help
+    -k|--keep       don't cleanup temporary header files and directories
+    -v|--verbose    print more verbose output
+
+Example in Linux kernel source tree:
+
+    \$ make headers_install
+    \$ cd usr/include
+    \$ $( readlink -f "$0" )
+
+EOF_HELP
+}
+
+# bash due to arithmetics and pipefail
+set -euo pipefail
+
+KEEP=0
+HELP=0
+
+# command line arguments
+for p in "$@"; do
+	case "$p" in
+		-k|--keep)
+			KEEP=1
+		;;
+		-h|--help)
+			HELP=1
+		;;
+		-v|--verbose)
+			set -x
+		;;
+		*)
+			help
+			echo "Unknown argument: $p"
+			exit 1
+		;;
+	esac
+done
+
+if [ "$HELP" != "0" ]; then help; exit 0; fi
+
+# sanity test
+if [ ! -d ./linux ]; then
+	echo Sanity check error: ./linux directory not found
+	echo Should be called in usr/include after \'make headers_install\'.
+	echo Returns number of failed files, 0 if none.
+	exit 1
+fi
+
+# Support CC variable for compiler and ccache, and cross compiling.
+# CC is used without quotes to support CC="ccache gcc".
+set +u
+if [ "$CC"foobar == "foobar" ]; then
+	CC=cc
+fi
+
+if [ "$CROSS_COMPILE"foobar != "foobar" ]; then
+	# Using gcc name since some cross compiler tool chains don't provide
+	# the cc symlink
+	CC="$CROSS_COMPILE"gcc
+fi
+set -u
+
+# Kernel headers refer to some gcc and libc headers so make them available.
+set +u
+if [ "$ARCH_TRIPLET"foobar == "foobar" ]; then
+	# Taking triplet from gcc/cpp
+	ARCH_TRIPLET="$( $CC -v -x c -E - < /dev/null 2>&1 | \
+			grep Target | sed -e 's/Target: //' )"
+fi
+
+if [ "$LIBC"foobar == "foobar" ]; then
+	# trying to grep libc includes from gcc/cpp defaults
+	_TEMP="$( $CC -v -x c -E - < /dev/null 2>&1 | \
+		sed -n -e '/^#include <...> search starts here:$/,/^End of search list.$/{//!p}' | \
+		sed -e 's/^\ \//\//g' | \
+		grep '/usr/include' )"
+
+	# sanity check and prepare LIBC dirs
+	for d in $_TEMP; do
+		if [ ! -d "$d" ]; then
+			echo "$d not a directory"
+			exit 1
+		fi
+		LIBC="$LIBC $d"
+	done
+fi
+set -u
+
+# Copy libc include files to temp directory for the tests.
+COMPILE_TEST_INC="$( readlink -f \
+		"$( mktemp -d ../headers_compile_test_include.XXXXXX )" )"
+
+# cleanup if keep not set
+if [ "$KEEP" = "0" ]; then
+	trap 'rm -rf "$COMPILE_TEST_INC"' EXIT
+else
+	trap 'printf \
+"Temporary directory not cleaned up! Remove manually:\n${COMPILE_TEST_INC}\n"' \
+		EXIT
+fi
+
+for d in $LIBC; do
+	# check if last part of dir is the arch triplet, cross compile paths
+	# can have it also elsewhere so just the last one counts.
+	if ! ( echo "$d" | egrep "$ARCH_TRIPLET$" > /dev/null ); then
+		# hopefully just main libc dir, e.g. /usr/include,
+		# follow symlinks from e.g. /usr/include/bits
+		cp -aL "$d"/* "$COMPILE_TEST_INC"/
+	elif ( echo "$d" | egrep "$ARCH_TRIPLET$" > /dev/null ); then
+		# hopefully the arch specific dir, e.g. /usr/include/x86_64-linux-gnu
+		cp -ar "$d"/* "$COMPILE_TEST_INC/"
+	else
+		echo "$d unexpected, bailing out"
+		exit 1
+	fi
+done
+
+# Simulate libc headers without kernel headers by removing
+# all known kernel header dirs from the copied libc ones.
+# This seems to magically work.
+_KERNEL_DIRS="$( find . -type d | grep -v '^\.$' )"
+( cd "$COMPILE_TEST_INC" && rm -rf $_KERNEL_DIRS )
+
+# GCC headers
+set +u
+if [ "$GCC_INC"foobar == "foobar" ]; then
+	# Take from $CC default system include paths, filter out
+	# /usr/local/include and /usr/include stuff first, then try to match
+	# for gcc.
+	_TEMP="$( $CC -v -x c -E - < /dev/null 2>&1 | \
+		sed -n -e '/^#include <...> search starts here:$/,/^End of search list.$/{//!p}' | \
+		sed -e 's/^\ \//\//g' | \
+		egrep -v '/usr/local/include' | \
+		egrep -v '/usr/include' | \
+		grep gcc | \
+		xargs )"
+
+	# merge and prepare for use with $CC
+	for d in $_TEMP; do
+		# sanity test
+		if [ ! -d "$d" ]; then
+			echo "$d: is not a directory"
+			exit 1
+		fi
+		GCC_INC="$GCC_INC -I $d"
+	done
+fi
+set -u
+
+# For each header file, try to compile it using the headers we prepared.
+_FAILED=0
+_PASSED=0
+for f in $( find . -name "*\.h" | xargs ); do
+	_FAIL=0
+
+	# compile test, CC not quoted to support ccache
+	echo $CC -Wall -c -nostdinc $GCC_INC -I . -I "$COMPILE_TEST_INC" -I "$COMPILE_TEST_INC/$ARCH_TRIPLET" -o /dev/null "$f"
+	$CC -Wall -c -nostdinc $GCC_INC -I . -I "$COMPILE_TEST_INC" -I "$COMPILE_TEST_INC/$ARCH_TRIPLET" -o /dev/null "$f" \
+		|| _FAIL=1
+
+	# report errors
+	if [ "$_FAIL" -gt 0 ]; then
+		echo "FAILED: $f"
+		_FAILED="$(( _FAILED + 1 ))"
+	else
+		echo "PASSED: $f"
+		_PASSED="$(( _PASSED + 1))"
+	fi
+done
+
+echo Statistics:
+echo "$_FAILED files failed the compile test."
+echo "$_PASSED files passed the compile test."
+
+exit "$_FAILED"
-- 
2.8.1