--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/filter-clang-warnings.py	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+#
+# Script to analyze warnings produced by clang.
+#
+# This file is part of GCC.
+#
+# GCC 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; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.  */
+#
+#
+#
+
+import sys
+import argparse
+
+def skip_warning(filename, message):
+    ignores = {
+            '': ['-Warray-bounds', '-Wmismatched-tags', 'gcc_gfc: -Wignored-attributes', '-Wchar-subscripts',
+                'string literal (potentially insecure): -Wformat-security', '-Wdeprecated-register',
+                '-Wvarargs', 'keyword is hidden by macro definition', "but the argument has type 'char *': -Wformat-pedantic",
+                '-Wnested-anon-types', 'qualifier in explicit instantiation of', 'attribute argument not supported: asm_fprintf',
+                'when in C++ mode, this behavior is deprecated', '-Wignored-attributes', '-Wgnu-zero-variadic-macro-arguments',
+                '-Wformat-security'],
+            'insn-modes.c': ['-Wshift-count-overflow'],
+            'insn-emit.c': ['-Wtautological-compare'],
+            'insn-attrtab.c': ['-Wparentheses-equality'],
+            'gimple-match.c': ['-Wunused-', '-Wtautological-compare'],
+            'generic-match.c': ['-Wunused-', '-Wtautological-compare'],
+            'i386.md': ['-Wparentheses-equality', '-Wtautological-compare'],
+            'sse.md': ['-Wparentheses-equality', '-Wtautological-compare'],
+            'genautomata.c': ['-Wstring-plus-int']
+
+    }
+
+    for name, ignores in ignores.items():
+        for i in ignores:
+            if name in filename and i in message:
+                return True
+
+    return False
+
+parser = argparse.ArgumentParser()
+parser.add_argument('log', help = 'Log file with clang warnings')
+args = parser.parse_args()
+
+lines = [l.strip() for l in open(args.log)]
+total = 0
+messages = []
+for l in lines:
+    token = ': warning: '
+    i = l.find(token)
+    if i != -1:
+        location = l[:i]
+        message = l[i + len(token):]
+        if not skip_warning(location, message):
+            total += 1
+            messages.append(l)
+
+for l in sorted(messages):
+    print(l)
+print('\nTotal warnings: %d' % total)