scripts/abi_check.py

#!/usr/bin/env python3

# This script is a small wrapper around the abi-compliance-checker and
# abi-dumper tools, applying them to compare the ABI and API of the library
# files from two different Git revisions within an Mbed TLS repository.
# The results of the comparison are formatted as HTML and stored at
# a configurable location. Returns 0 on success, 1 on ABI/API non-compliance,
# and 2 if there is an error while running the script.
# Note: must be run from Mbed TLS root.

import os
import sys
import traceback
import shutil
import subprocess
import argparse
import logging
import tempfile


class AbiChecker(object):

    def __init__(self, report_dir, old_rev, new_rev, keep_all_reports):
        self.repo_path = "."
        self.log = None
        self.setup_logger()
        self.report_dir = os.path.abspath(report_dir)
        self.keep_all_reports = keep_all_reports
        self.should_keep_report_dir = os.path.isdir(self.report_dir)
        self.old_rev = old_rev
        self.new_rev = new_rev
        self.mbedtls_modules = ["libmbedcrypto", "libmbedtls", "libmbedx509"]
        self.old_dumps = {}
        self.new_dumps = {}
        self.git_command = "git"
        self.make_command = "make"

    def check_repo_path(self):
        if not __file__ == os.path.join(".", "scripts", "abi_check.py"):
            raise Exception("Must be run from Mbed TLS root")

    def setup_logger(self):
        self.log = logging.getLogger()
        self.log.setLevel(logging.INFO)
        self.log.addHandler(logging.StreamHandler())

    def check_abi_tools_are_installed(self):
        for command in ["abi-dumper", "abi-compliance-checker"]:
            if not shutil.which(command):
                raise Exception("{} not installed, aborting".format(command))

    def get_clean_worktree_for_git_revision(self, git_rev):
        self.log.info(
            "Checking out git worktree for revision {}".format(git_rev)
        )
        git_worktree_path = tempfile.mkdtemp()
        worktree_process = subprocess.Popen(
            [self.git_command, "worktree", "add", git_worktree_path, git_rev],
            cwd=self.repo_path,
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT
        )
        worktree_output, _ = worktree_process.communicate()
        self.log.info(worktree_output.decode("utf-8"))
        if worktree_process.returncode != 0:
            raise Exception("Checking out worktree failed, aborting")
        return git_worktree_path

    def build_shared_libraries(self, git_worktree_path):
        my_environment = os.environ.copy()
        my_environment["CFLAGS"] = "-g -Og"
        my_environment["SHARED"] = "1"
        make_process = subprocess.Popen(
            self.make_command,
            env=my_environment,
            cwd=git_worktree_path,
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT
        )
        make_output, _ = make_process.communicate()
        self.log.info(make_output.decode("utf-8"))
        if make_process.returncode != 0:
            raise Exception("make failed, aborting")

    def get_abi_dumps_from_shared_libraries(self, git_ref, git_worktree_path):
        abi_dumps = {}
        for mbed_module in self.mbedtls_modules:
            output_path = os.path.join(
                self.report_dir, "{}-{}.dump".format(mbed_module, git_ref)
            )
            abi_dump_command = [
                "abi-dumper",
                os.path.join(
                    git_worktree_path, "library", mbed_module + ".so"),
                "-o", output_path,
                "-lver", git_ref
            ]
            abi_dump_process = subprocess.Popen(
                abi_dump_command,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT
            )
            abi_dump_output, _ = abi_dump_process.communicate()
            self.log.info(abi_dump_output.decode("utf-8"))
            if abi_dump_process.returncode != 0:
                raise Exception("abi-dumper failed, aborting")
            abi_dumps[mbed_module] = output_path
        return abi_dumps

    def cleanup_worktree(self, git_worktree_path):
        shutil.rmtree(git_worktree_path)
        worktree_process = subprocess.Popen(
            [self.git_command, "worktree", "prune"],
            cwd=self.repo_path,
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT
        )
        worktree_output, _ = worktree_process.communicate()
        self.log.info(worktree_output.decode("utf-8"))
        if worktree_process.returncode != 0:
            raise Exception("Worktree cleanup failed, aborting")

    def get_abi_dump_for_ref(self, git_rev):
        git_worktree_path = self.get_clean_worktree_for_git_revision(git_rev)
        self.build_shared_libraries(git_worktree_path)
        abi_dumps = self.get_abi_dumps_from_shared_libraries(
            git_rev, git_worktree_path
        )
        self.cleanup_worktree(git_worktree_path)
        return abi_dumps

    def get_abi_compatibility_report(self):
        compatibility_report = ""
        compliance_return_code = 0
        for mbed_module in self.mbedtls_modules:
            output_path = os.path.join(
                self.report_dir, "{}-{}-{}.html".format(
                    mbed_module, self.old_rev, self.new_rev
                )
            )
            abi_compliance_command = [
                "abi-compliance-checker",
                "-l", mbed_module,
                "-old", self.old_dumps[mbed_module],
                "-new", self.new_dumps[mbed_module],
                "-strict",
                "-report-path", output_path
            ]
            abi_compliance_process = subprocess.Popen(
                abi_compliance_command,
                stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT
            )
            abi_compliance_output, _ = abi_compliance_process.communicate()
            self.log.info(abi_compliance_output.decode("utf-8"))
            if abi_compliance_process.returncode == 0:
                compatibility_report += (
                    "No compatibility issues for {}\n".format(mbed_module)
                )
                if not self.keep_all_reports:
                    os.remove(output_path)
            elif abi_compliance_process.returncode == 1:
                compliance_return_code = 1
                self.should_keep_report_dir = True
                compatibility_report += (
                    "Compatibility issues found for {}, "
                    "for details see {}\n".format(mbed_module, output_path)
                )
            else:
                raise Exception(
                    "abi-compliance-checker failed with a return code of {},"
                    " aborting".format(abi_compliance_process.returncode)
                )
            os.remove(self.old_dumps[mbed_module])
            os.remove(self.new_dumps[mbed_module])
        if not self.should_keep_report_dir and not self.keep_all_reports:
            os.rmdir(self.report_dir)
        self.log.info(compatibility_report)
        return compliance_return_code

    def check_for_abi_changes(self):
        self.check_repo_path()
        self.check_abi_tools_are_installed()
        self.old_dumps = self.get_abi_dump_for_ref(self.old_rev)
        self.new_dumps = self.get_abi_dump_for_ref(self.new_rev)
        return self.get_abi_compatibility_report()


def run_main():
    try:
        parser = argparse.ArgumentParser(
            description=(
                "This script is a small wrapper around the "
                "abi-compliance-checker and abi-dumper tools, applying them "
                "to compare the ABI and API of the library files from two "
                "different Git revisions within an Mbed TLS repository."
                " The results of the comparison are formatted as HTML and"
                " stored at a configurable location. Returns 0 on success, "
                "1 on ABI/API non-compliance, and 2 if there is an error "
                "while running the script. # Note: must be run from "
                "Mbed TLS root."
            )
        )
        parser.add_argument(
            "-r", "--report_dir", type=str, default="reports",
            help="directory where reports are stored, default is reports",
        )
        parser.add_argument(
            "-k", "--keep_all_reports", action="store_true",
            help="keep all reports, even if there are no compatibility issues",
        )
        parser.add_argument(
            "-o", "--old_rev", type=str, help="revision for old version",
            required=True
        )
        parser.add_argument(
            "-n", "--new_rev", type=str, help="revision for new version",
            required=True
        )
        abi_args = parser.parse_args()
        abi_check = AbiChecker(
            abi_args.report_dir, abi_args.old_rev,
            abi_args.new_rev, abi_args.keep_all_reports
        )
        return_code = abi_check.check_for_abi_changes()
        sys.exit(return_code)
    except Exception as error:
        traceback.print_exc(error)
        sys.exit(2)


if __name__ == "__main__":
    run_main()