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>

2 files changed, 343 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()
diff --git a/extras/scripts/tests/test_crcchecker.sh b/extras/scripts/tests/test_crcchecker.sh
new file mode 100755
index 00000000000..7cfda086483
--- /dev/null
+++ b/extras/scripts/tests/test_crcchecker.sh
@@ -0,0 +1,140 @@
+#!/bin/sh
+set -eux
+
+TMPDIR=$(mktemp -d /tmp/vpp-crccheck-test-XXXXX)
+
+CURR_ROOT=$(git rev-parse --show-toplevel)
+CURR_DIR=$(pwd)
+
+verify_check_patchset_fails() {
+	if (extras/scripts/crcchecker.py --check-patchset); then
+		echo "ERROR - check succeeded, it should have failed!"
+		exit 1;
+	fi
+}
+
+finish() {
+	if [ -e "$TMPDIR" ]; then
+		echo "Temporary directory is: $TMPDIR"
+	fi
+}
+trap finish EXIT
+
+
+# make a copy of the current repo that we can play with
+cd ${TMPDIR}
+mkdir misc-files
+git clone ${CURR_ROOT} vpp-uut
+cd vpp-uut
+
+# maybe grab the CRC checker
+# git fetch "https://gerrit.fd.io/r/vpp" refs/changes/81/26881/14 && git cherry-pick FETCH_HEAD || echo "Already there"
+
+
+echo "TEST 1: Check the current patchset..."
+extras/scripts/crcchecker.py --check-patchset
+
+echo "TEST 2: Dumping the current manifest..."
+extras/scripts/crcchecker.py --dump-manifest >${TMPDIR}/misc-files/manifest.txt
+
+echo "TEST 3: Checking the 20.01 version of acl.api...."
+extras/scripts/crcchecker.py --git-revision v20.01 src/plugins/acl/acl.api
+
+echo "TEST 4: Add a new field into a message in acl.api, and check patchset - must fail..."
+sed -i -e 's#vpe_pid;#vpe_pid; u32 sneaky_new_field;#' src/plugins/acl/acl.api
+verify_check_patchset_fails
+
+echo "TEST 5: Rename the changed acl.api file and not add it to git... must fail (due to deletion of the APIs)..."
+mv src/plugins/acl/acl.api src/plugins/acl/acl_new.api
+verify_check_patchset_fails
+
+echo "TEST 6: Add the renamed file to git commit... must fail (due to addition of the fields)..."
+git add src/plugins/acl/acl_new.api
+git commit -m "added acl_new.api"
+verify_check_patchset_fails
+
+echo "TEST 7: Verify we can delete deprecated message"
+git commit -a -m "reset"
+cat >crccheck.api <<EOL
+option version="1.0.0";
+autoreply define crccheck
+{
+  option deprecated="v20.11";
+  bool foo;
+};
+EOL
+git add crccheck.api
+git commit -m "deprecated api";
+# delete API
+cat >crccheck.api <<EOL
+option version="1.0.0";
+autoreply define crccheck_2
+{
+  bool foo;
+};
+EOL
+git add crccheck.api
+git commit -m "deprecated api";
+extras/scripts/crcchecker.py --check-patchset
+
+echo "TEST 8: Verify that we can not rename a non-deprecated message"
+sed -i -e 's/crccheck_2/crccheck_3/g' crccheck.api
+git add crccheck.api
+git commit -m "renamed api";
+verify_check_patchset_fails
+# fix it.
+sed -i -e 's/crccheck_3/crccheck_2/g' crccheck.api
+git commit -a --amend -m "empty commit after we renamed api back" --allow-empty
+
+echo "TEST 9: Verify that the check fails if the changes are not committed"
+cat >>crccheck.api <<EOL
+autoreply define crc_new_check_in_progress
+{
+  option status="in_progress";
+  bool foobar;
+};
+EOL
+verify_check_patchset_fails
+
+echo "TEST10: Verify that the in-progress message can be added"
+git add crccheck.api
+git commit -m "added a new in-progress api";
+extras/scripts/crcchecker.py --check-patchset
+
+echo "TEST11: Verify we can rename an in-progress API"
+sed -i -e 's/crc_new_check_in_progress/crc_new_check_in_progress_2/g' crccheck.api
+git add crccheck.api
+git commit -m "renamed in-progress api";
+extras/scripts/crcchecker.py --check-patchset
+
+echo "TEST12: Verify we can add a field to an in-progress API"
+sed -i -e 's/foobar;/foobar; bool new_baz;/g' crccheck.api
+git add crccheck.api
+git commit -m "new field added in in-progress api";
+extras/scripts/crcchecker.py --check-patchset
+
+echo "TEST13: Verify we fail the check if the file can not be compiled"
+cat >crccheck2.api <<EOL
+option version="0.0.1";
+autoreply define spot_the_error
+{
+  option status="in_progress"
+  bool something_important;
+};
+EOL
+git add crccheck2.api
+git commit -m "a new message with a syntax error";
+verify_check_patchset_fails
+
+# get rid of the "erroneous" commit in the previous test
+git reset --hard HEAD~1
+
+echo "TEST: All tests got the expected result, cleaning up."
+
+# done with all the tests - clean up
+cd ${CURR_DIR}
+
+# beware of empty variables, careful with deletion
+rm -rf ${TMPDIR}/vpp-uut
+rm -rf ${TMPDIR}/misc-files
+rmdir ${TMPDIR}