Revert "scripts: gcc-wrapper: Use wrapper to check compiler warnings"

gcc-wrapper simulates building with -Werror, but with a few hardcoded
file:line combinations that don't get promoted to errors.

We're already building with -Werror anyway without issue, so this script
is redundant and just adds a dependency on Python 2.

This reverts commit ca2dc1f081b0a15d28b5b0d3f032b89aa819b65c.

Change-Id: Id4a75ff16fb75e7d621c532a37ddcbe0efa01040
Signed-off-by: Greg Hackmann <ghackmann@google.com>

Makefile

@@ -377,7 +377,7 @@ endif
 # Make variables (CC, etc...)
 AS		= $(CROSS_COMPILE)as
 LD		= $(CROSS_COMPILE)ld
-REAL_CC		= $(CROSS_COMPILE)gcc
+CC		= $(CROSS_COMPILE)gcc
 LDGOLD		= $(CROSS_COMPILE)ld.gold
 CPP		= $(CC) -E
 AR		= $(CROSS_COMPILE)ar
@@ -393,10 +393,6 @@ PERL		= perl
 PYTHON		= python
 CHECK		= sparse
 
-# Use the wrapper for the compiler.  This wrapper scans for new
-# warnings and causes the build to stop upon encountering them
-CC		= $(PYTHON) $(srctree)/scripts/gcc-wrapper.py $(REAL_CC)
-
 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 		  -Wbitwise -Wno-return-void $(CF)
 NOSTDINC_FLAGS  =

scripts/gcc-wrapper.py

@@ -1,95 +0,0 @@
-#! /usr/bin/env python2
-# -*- coding: utf-8 -*-
-
-# Copyright (c) 2011-2017, 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([
- ])
-
-# 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 >> sys.stderr, "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 >> sys.stderr, line,
-            interpret_warning(line)
-
-        result = proc.wait()
-    except OSError as e:
-        result = e.errno
-        if result == errno.ENOENT:
-            print >> sys.stderr, args[0] + ':',e.strerror
-            print >> sys.stderr, 'Is your PATH set correctly?'
-        else:
-            print >> sys.stderr, ' '.join(args), str(e)
-
-    return result
-
-if __name__ == '__main__':
-    status = run_gcc()
-    sys.exit(status)