vppapigen: api crc checker

crcchecker is a tool for enforcement of the binary API.

1. Production APIs should never change.
2. An API can be deprecated across three release cycles.
   Release 1: API is marked as deprecated.
   option deprecated="vyy.mm";
   option replaced_by="new_api_2";
   Release 2: both old and new APIs are supported
   Release 3: the deprecated API is deleted.
3. APIs that are experimental / not released are not checked.
   An API message can be individually marked as in progress, by:
   option status="in_progress";
   In the API definition.

The definition of a "production API" is if the major version in the API file is > 0.

extras/scripts/crcchecker.py --check-patchset # returns -1 if backwards incompatible
extras/scripts/crcchecker.py --dump-manifest
extras/scripts/crcchecker.py --git-revision v20.01 <files>
extras/scripts/crcchecker.py -- diff <oldfile> <newfile>

This patch integrates the tool in "make checkstyle-api".
A future patch is required to integrate the tool in the verify job.
I.e. this patch does not enable enforcement through Jenkins.

Change-Id: I5f13c0976d8a12a58131b3e270f2dc9c00dc7d8c
Type: feature
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 203 insertions, 0 deletions

diff --git a/extras/scripts/crcchecker.py b/extras/scripts/crcchecker.py
new file mode 100755
index 00000000000..7f83d2e6d85
--- /dev/null
+++ b/extras/scripts/crcchecker.py
@@ -0,0 +1,203 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import json
+import argparse
+from subprocess import run, PIPE, check_output, CalledProcessError
+
+rootdir = os.path.dirname(os.path.realpath(__file__)) + '/../..'
+
+def crc_from_apigen(revision, filename):
+    if not revision and not os.path.isfile(filename):
+        print(f'skipping: {filename}', file=sys.stderr)
+        return {}
+    apigen_bin = f'{rootdir}/src/tools/vppapigen/vppapigen.py'
+    if revision:
+        apigen = (f'{apigen_bin} --git-revision {revision} --includedir src '
+                  f'--input {filename} CRC')
+    else:
+        apigen = (f'{apigen_bin} --includedir src --input {filename} CRC')
+    rv = run(apigen.split(), stdout=PIPE, stderr=PIPE)
+    if rv.returncode == 2: # No such file
+        print(f'skipping: {revision}:{filename} {rv}', file=sys.stderr)
+        return {}
+    if rv.returncode != 0:
+        print(f'vppapigen failed for {revision}:{filename} with command\n {apigen}\n error: {rv}',
+              rv.stderr.decode('ascii'), file=sys.stderr)
+        sys.exit(-2)
+
+    return json.loads(rv.stdout)
+
+
+def dict_compare(d1, d2):
+    d1_keys = set(d1.keys())
+    d2_keys = set(d2.keys())
+    intersect_keys = d1_keys.intersection(d2_keys)
+    added = d1_keys - d2_keys
+    removed = d2_keys - d1_keys
+    modified = {o: (d1[o], d2[o]) for o in intersect_keys if d1[o]['crc'] != d2[o]['crc']}
+    same = set(o for o in intersect_keys if d1[o] == d2[o])
+    return added, removed, modified, same
+
+
+def filelist_from_git_ls():
+    filelist = []
+    git_ls = 'git ls-files *.api'
+    rv = run(git_ls.split(), stdout=PIPE, stderr=PIPE)
+    if rv.returncode != 0:
+        sys.exit(rv.returncode)
+
+    for l in rv.stdout.decode('ascii').split('\n'):
+        if len(l):
+            filelist.append(l)
+    return filelist
+
+
+def is_uncommitted_changes():
+    git_status = 'git status --porcelain -uno'
+    rv = run(git_status.split(), stdout=PIPE, stderr=PIPE)
+    if rv.returncode != 0:
+        sys.exit(rv.returncode)
+
+    if len(rv.stdout):
+        return True
+    return False
+
+
+def filelist_from_git_grep(filename):
+    filelist = []
+    try:
+        rv = check_output(f'git grep -e "import .*{filename}" -- *.api', shell=True)
+    except CalledProcessError as err:
+        return []
+        print('RV', err.returncode)
+    for l in rv.decode('ascii').split('\n'):
+        if l:
+            f, p = l.split(':')
+            filelist.append(f)
+    return filelist
+
+
+def filelist_from_patchset():
+    filelist = []
+    git_cmd = '((git diff HEAD~1.. --name-only;git ls-files -m) | sort -u)'
+    rv = check_output(git_cmd, shell=True)
+    for l in rv.decode('ascii').split('\n'):
+        if len(l) and os.path.splitext(l)[1] == '.api':
+            filelist.append(l)
+
+    # Check for dependencies (imports)
+    imported_files = []
+    for f in filelist:
+        imported_files.extend(filelist_from_git_grep(os.path.basename(f)))
+
+    filelist.extend(imported_files)
+    return set(filelist)
+
+def is_deprecated(d, k):
+    if 'options' in d[k] and 'deprecated' in d[k]['options']:
+        return True
+    return False
+
+def is_in_progress(d, k):
+    try:
+        if d[k]['options']['status'] == 'in_progress':
+            return True
+    except:
+        return False
+
+def report(old, new, added, removed, modified, same):
+    backwards_incompatible = 0
+    for k in added:
+        print(f'added: {k}')
+    for k in removed:
+        oldversion = int(old[k]['version'])
+        if oldversion > 0 and not is_deprecated(old, k) and not is_in_progress(old, k):
+            backwards_incompatible += 1
+            print(f'removed: ** {k}')
+        else:
+            print(f'removed: {k}')
+    for k in modified.keys():
+        oldversion = int(old[k]['version'])
+        newversion = int(new[k]['version'])
+        if oldversion > 0 and not is_in_progress(old, k):
+            backwards_incompatible += 1
+            print(f'modified: ** {k}')
+        else:
+            print(f'modified: {k}')
+    return backwards_incompatible
+
+
+def main():
+    parser = argparse.ArgumentParser(description='VPP CRC checker.')
+    parser.add_argument('--git-revision',
+                        help='Git revision to compare against')
+    parser.add_argument('--dump-manifest', action='store_true',
+                        help='Dump CRC for all messages')
+    parser.add_argument('--check-patchset', action='store_true',
+                        help='Dump CRC for all messages')
+    parser.add_argument('files', nargs='*')
+    parser.add_argument('--diff', help='Files to compare (on filesystem)', nargs=2)
+
+    args = parser.parse_args()
+
+    if args.diff and args.files:
+        parser.print_help()
+        sys.exit(-1)
+
+    # Diff two files
+    if args.diff:
+        oldcrcs = crc_from_apigen(None, args.diff[0])
+        newcrcs = crc_from_apigen(None, args.diff[1])
+        added, removed, modified, same = dict_compare(newcrcs, oldcrcs)
+        backwards_incompatible = report(oldcrcs, newcrcs, added, removed, modified, same)
+        sys.exit(0)
+
+    # Dump CRC for messages in given files / revision
+    if args.dump_manifest:
+        files = args.files if args.files else filelist_from_git_ls()
+        crcs = {}
+        for f in files:
+            crcs.update(crc_from_apigen(args.git_revision, f))
+        for k, v in crcs.items():
+            print(f'{k}: {v}')
+        sys.exit(0)
+
+    # Find changes between current patchset and given revision (previous)
+    if args.check_patchset:
+        if args.git_revision:
+            print('Argument git-revision ignored', file=sys.stderr)
+        # Check there are no uncomitted changes
+        if is_uncommitted_changes():
+            print('Please stash or commit changes in workspace', file=sys.stderr)
+            sys.exit(-1)
+        files = filelist_from_patchset()
+    else:
+        # Find changes between current workspace and revision
+        # Find changes between a given file and a revision
+        files = args.files if args.files else filelist_from_git_ls()
+
+    revision = args.git_revision if args.git_revision else 'HEAD~1'
+
+    oldcrcs = {}
+    newcrcs = {}
+    for f in files:
+        newcrcs.update(crc_from_apigen(None, f))
+        oldcrcs.update(crc_from_apigen(revision, f))
+
+    added, removed, modified, same = dict_compare(newcrcs, oldcrcs)
+    backwards_incompatible = report(oldcrcs, newcrcs, added, removed, modified, same)
+
+    if args.check_patchset:
+        if backwards_incompatible:
+            # alert on changing production API
+            print("crcchecker: Changing production APIs in an incompatible way", file=sys.stderr)
+            sys.exit(-1)
+        else:
+            print('*' * 67)
+            print('* VPP CHECKAPI SUCCESSFULLY COMPLETED')
+            print('*' * 67)
+
+if __name__ == '__main__':
+    main()