linux/scripts/gcc-wrapper.py

#! /usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * Neither the name of The Linux Foundation nor
#       the names of its contributors may be used to endorse or promote
#       products derived from this software without specific prior written
#       permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# Invoke gcc, looking for warnings, and causing a failure if there are
# non-whitelisted warnings.

import errno
import re
import os
import sys
import subprocess

# Note that gcc uses unicode, which may depend on the locale.  TODO:
# force LANG to be set to en_US.UTF-8 to get consistent warnings.

allowed_warnings = set([
    "core.c:142", # drivers/regulator/core.c:142:6: warning: unused variable 'i'
    "posix-cpu-timers.c:1268", # kernel/time/posix-cpu-timers.c:1268:13: warning: 'now' may be used uninitialized in this function
    "af_unix.c:1036", # net/unix/af_unix.c:1036:20: warning: 'hash' may be used uninitialized in this function
    "sunxi_sram.c:214", # drivers/soc/sunxi/sunxi_sram.c:214:24: warning: 'device' may be used uninitialized in this function
    "ks8851.c:298", # drivers/net/ethernet/micrel/ks8851.c:298:2: warning: 'rxb[0]' may be used uninitialized in this function
    "ks8851.c:421", # drivers/net/ethernet/micrel/ks8851.c:421:20: warning: 'rxb[0]' may be used uninitialized in this function
    "compat_binfmt_elf.c:58", # fs/compat_binfmt_elf.c:58:13: warning: 'cputime_to_compat_timeval' defined but not used
    "cgroup.c:2132", # kernel/cgroup.c:2132:13: warning: 'root' may be used uninitialized in this function
    "lowmemorykiller.c:174", # drivers/staging/android/lowmemorykiller.c:174:3: warning: ISO C90 forbids mixed declarations and code
    "inet6_connection_sock.c:89", # net/ipv6/inet6_connection_sock.c:89:32: warning: passing argument 1 of 'sock_i_uid' discards 'const' qualifier from pointer target type
    "inet_connection_sock.c:423", # net/ipv4/inet_connection_sock.c:423:283: warning: passing argument 1 of 'sock_i_uid' discards 'const' qualifier from pointer target type
    "inet_connection_sock.c:460", # net/ipv4/inet_connection_sock.c:460:283: warning: passing argument 1 of 'sock_i_uid' discards 'const' qualifier from pointer target type
    "watchdog.c:122", # kernel/watchdog.c:122:22: warning: 'hardlockup_allcpu_dumped' defined but not used
 ])

# Capture the name of the object file, can find it.
ofile = None

warning_re = re.compile(r'''(.*/|)([^/]+\.[a-z]+:\d+):(\d+:)? warning:''')
def interpret_warning(line):
    """Decode the message from gcc.  The messages we care about have a filename, and a warning"""
    line = line.rstrip('\n')
    m = warning_re.match(line)
    if m and m.group(2) not in allowed_warnings:
        print "error, forbidden warning:", m.group(2)

        # If there is a warning, remove any object if it exists.
        if ofile:
            try:
                os.remove(ofile)
            except OSError:
                pass
        sys.exit(1)

def run_gcc():
    args = sys.argv[1:]
    # Look for -o
    try:
        i = args.index('-o')
        global ofile
        ofile = args[i+1]
    except (ValueError, IndexError):
        pass

    compiler = sys.argv[0]

    try:
        proc = subprocess.Popen(args, stderr=subprocess.PIPE)
        for line in proc.stderr:
            print line,
            interpret_warning(line)

        result = proc.wait()
    except OSError as e:
        result = e.errno
        if result == errno.ENOENT:
            print args[0] + ':',e.strerror
            print 'Is your PATH set correctly?'
        else:
            print ' '.join(args), str(e)

    return result

if __name__ == '__main__':
    status = run_gcc()
    sys.exit(status)