style: Add a style checker that doesn't depend on Mercurial

The current style checker script, hgstyle.py, assumes that it is being
run from Mercurial. This means that it depends on the Mercurial Python
libraries, which aren't necessarily present if using git. This
changeset adds a new style checker script, style.py, that has
been designed to be run from the command line.

The script has support for detecting which revision control system is
used and is able to query both git and Mercurial for changes. This
enables the script to operate on modified regions and/or all of the
modified files in the repository.

Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Steve Reinhardt <steve.reinhardt@amd.com>

--HG--
extra : rebase_source : 2b420aff79d190f32557bc8822518cbc5d93e999

util/style.py

@@ -0,0 +1,126 @@
+#! /usr/bin/env python
+#
+# Copyright (c) 2016 ARM Limited
+# All rights reserved
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# 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 copyright holders 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 AND FITNESS FOR
+# A PARTICULAR PURPOSE 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.
+#
+# Authors: Andreas Sandberg
+
+import os
+import sys
+
+from style.file_types import lang_type
+from style.verifiers import all_verifiers
+from style.region import all_regions
+
+from style.style import StdioUI
+from style import repo
+
+def verify(filename, regions=all_regions, verbose=False):
+    ui = StdioUI()
+    opts = {}
+    base = os.path.join(os.path.dirname(__file__), "..")
+    verifiers = [ v(ui, opts, base=base) for v in all_verifiers ]
+
+    if verbose:
+        print "Verifying %s[%s]..." % (filename, regions)
+    for verifier in verifiers:
+        if verbose:
+            print "Applying %s (%s)" % (
+                verifier.test_name, verifier.__class__.__name__)
+        if verifier.apply(filename, regions=regions):
+            return False
+    return True
+
+def detect_repo():
+    repo_classes = repo.detect_repo()
+    if not repo_classes:
+        print >> sys.stderr, "Error: Failed to detect repository type, no " \
+            "known repository type found."
+        sys.exit(1)
+    elif len(repo_classes) > 1:
+        print >> sys.stderr, "Error: Detected multiple repository types."
+        sys.exit(1)
+    else:
+        return repo_classes[0]()
+
+repo_types = {
+    "auto" : detect_repo,
+    "none" : lambda : None,
+    "git" : repo.GitRepo,
+    "hg" : repo.MercurialRepo,
+}
+
+if __name__ == '__main__':
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description="Check a file for gem5 style violations",
+        epilog="""If no files are specified, the style checker tries to
+        determine the list of modified and added files from the version
+        control system and checks those."""
+    )
+
+    parser.add_argument("--verbose", "-v", action="count",
+                        help="Produce verbose output")
+
+    parser.add_argument("--modifications", "-m", action="store_true",
+                        help="""Apply the style checker to modified regions
+                        instead of whole files""")
+
+    parser.add_argument("--repo-type", choices=repo_types, default="auto",
+                        help="Repository type to use to detect changes")
+
+    parser.add_argument("files", metavar="FILE", nargs="*",
+                        type=str,
+                        help="Source file(s) to inspect")
+
+    args = parser.parse_args()
+
+    repo = repo_types[args.repo_type]()
+
+    files = args.files
+    if not files and repo:
+        added, modified = repo.staged_files()
+        files = [ repo.file_path(f) for f in added + modified ]
+
+    for filename in files:
+        if args.modifications and repo and repo.in_repo(filename):
+            regions = repo.modified_regions(filename)
+        else:
+            regions = all_regions
+
+        if not verify(filename, regions=regions,
+                      verbose=args.verbose):
+            sys.exit(1)