Revert "Revert "scripts: gcc-wrapper: Use wrapper to check compiler w…

…arnings""

This reverts commit 333fbf2.

Signed-off-by: Sudeep Duhoon <rishi.gothic@gmail.com>

Makefile

@@ -395,6 +395,10 @@ 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

@@ -0,0 +1,95 @@
+#! /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)