analyzer.py

# -------------------------------------------------------------------------
#
#  Part of the CodeChecker project, under the Apache License v2.0 with
#  LLVM Exceptions. See LICENSE for license information.
#  SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#
# -------------------------------------------------------------------------
"""
Clang Static Analyzer related functions.
"""

import os
from pathlib import Path
import plistlib
import re
import subprocess
import sys
from typing import List, Optional, Tuple

from semver.version import Version

from codechecker_common import util
from codechecker_common.logger import get_logger

from codechecker_analyzer import analyzer_context, env, host_check
from codechecker_statistics_collector.collectors.special_return_value import \
    SpecialReturnValueCollector
from codechecker_statistics_collector.collectors.return_value import \
    ReturnValueCollector

from .. import analyzer_base
from ..config_handler import CheckerState
from ..flag import has_flag
from ..flag import prepend_all

from . import config_handler
from . import ctu_triple_arch
from .result_handler import ClangSAResultHandler

LOG = get_logger('analyzer')


def clang_command_output(command: List[str]) -> str:
    """
    Runs the given Clang command in its proper environment and returns its
    output as a string.
    Throws an exception if the command cannot be executed as a subprocess.
    """
    return subprocess.check_output(
        command,
        stderr=subprocess.STDOUT,
        env=analyzer_context.get_context().get_env_for_bin(command[0]),
        universal_newlines=True,
        encoding="utf-8",
        errors="ignore")


def parse_clang_help_page(
    command: List[str],
    start_label: str
) -> List[Tuple[str, str]]:
    """
    Parse the clang help page starting from a specific label.
    Returns a list of (flag, description) tuples.
    """
    try:
        help_page = clang_command_output(command)
    except (subprocess.CalledProcessError, OSError):
        LOG.debug("Failed to run '%s' command!", command)
        return []

    try:
        help_page = help_page[help_page.index(start_label) + len(start_label):]
    except ValueError:
        return []

    # This regex will match lines which contain only a flag or a flag and a
    # description: '  <flag>', '  <flag> <description>'.
    start_new_option_rgx = \
        re.compile(r"^\s{2}(?P<flag>\S+)(\s(?P<desc>[^\n]+))?$")

    # This regex will match lines which contain description for the previous
    # flag: '     <description>'
    prev_help_desc_rgx = \
        re.compile(r"^\s{3,}(?P<desc>[^\n]+)$")

    res = []

    flag = None
    desc = []
    for line in help_page.splitlines():
        m = start_new_option_rgx.match(line)
        if m:
            if flag and desc:
                res.append((flag, ' '.join(desc)))
                flag = None
                desc = []

            flag = m.group("flag")
        else:
            m = prev_help_desc_rgx.match(line)

        if m and m.group("desc"):
            desc.append(m.group("desc").strip())

    if flag and desc:
        res.append((flag, ' '.join(desc)))

    return res


def _is_user_disabled_checker(checker, ordered_checkers):
    """
    This function returns True if the given checker is disabled by the user
    explicitly by a --disable flag.
    """
    if not ordered_checkers:
        return False

    disabled_checkers = (c for c, enabled in ordered_checkers if not enabled)

    return any(checker.startswith(c) for c in disabled_checkers)


class ClangSA(analyzer_base.SourceAnalyzer):
    """
    Constructs clang static analyzer commands.
    """
    ANALYZER_NAME = 'clangsa'

    __additional_analyzer_config = [
        analyzer_base.AnalyzerConfig(
            'cc-verbatim-args-file',
            'A file path containing flags that are forwarded verbatim to the '
            'analyzer tool. E.g.: cc-verbatim-args-file=<filepath>',
            util.ExistingPath)
    ]

    def __init__(self, cfg_handler, buildaction):
        super().__init__(cfg_handler, buildaction)
        self.__disable_ctu = False
        self.__checker_configs = []
        self.__disabled_checkers = []

    @classmethod
    def analyzer_binary(cls):
        """
        Return the path of the analyzer binary.
        """
        return analyzer_context.get_context() \
            .analyzer_binaries[cls.ANALYZER_NAME]

    @classmethod
    def analyzer_plugins(cls) -> List[str]:
        """
        Return the list of .so file paths which contain checker plugins to
        ClangSA.
        """
        plugin_dir = analyzer_context.get_context().checker_plugin

        clangsa_plugin_dir = env.get_clangsa_plugin_dir()
        is_analyzer_from_path = env.is_analyzer_from_path()
        if is_analyzer_from_path:
            if not clangsa_plugin_dir:
                return []

            # If the CC_ANALYZERS_FROM_PATH and CC_CLANGSA_PLUGIN_DIR
            # environment variables are set we will use this value as the
            # plugin directory.
            plugin_dir = clangsa_plugin_dir

        if not plugin_dir or not os.path.exists(plugin_dir):
            return []

        return [os.path.join(plugin_dir, f)
                for f in os.listdir(plugin_dir)
                if os.path.isfile(os.path.join(plugin_dir, f))
                and f.endswith(".so")]

    @classmethod
    def __add_plugin_load_flags(cls, analyzer_cmd: List[str]):
        """
        ClangSA can be extended with checker plugins. This function extends a
        clang command with these plugins.
        """
        for plugin in ClangSA.analyzer_plugins():
            analyzer_cmd.extend(["-load", plugin])

    @staticmethod
    def parse_version(version_txt) -> Optional[Version]:
        """
        Parse the version string of the analyzer.
        """
        version_txt = version_txt.strip().removesuffix("git")
        return Version.parse(version_txt)

    @classmethod
    def get_binary_version(cls) -> Optional[Version]:
        # No need to LOG here, we will emit a warning later anyway.
        if not cls.analyzer_binary():
            return None

        environ = analyzer_context.get_context().get_env_for_bin(
            cls.analyzer_binary())

        version = [cls.analyzer_binary(), '-dumpversion']

        try:
            output = subprocess.check_output(version,
                                             env=environ,
                                             universal_newlines=True,
                                             encoding="utf-8",
                                             errors="ignore")
            return ClangSA.parse_version(output)
        except (subprocess.CalledProcessError, OSError) as oerr:
            LOG.warning("Failed to get analyzer version: %s",
                        ' '.join(version))
            LOG.warning(oerr)

        return None

    @classmethod
    def ctu_mapping(cls):
        """Clang version dependent ctu mapping tool path and mapping file name.

        The path of the mapping tool, which is assumed to be located
        inside the installed directory of the analyzer. Certain binary
        distributions can postfix the tool name with the major version
        number, the number and the tool name being separated by a dash. By
        default the shorter name is looked up, then if it is not found the
        postfixed.
        """
        clang_version = cls.get_binary_version()
        if not clang_version:
            LOG.debug(
                "No clang version information. "
                "Can not detect ctu mapping tool.")
            return None, None

        old_mapping_tool_name = 'clang-func-mapping'
        old_mapping_file_name = 'externalFnMap.txt'

        new_mapping_tool_name = 'clang-extdef-mapping'
        new_mapping_file_name = 'externalDefMap.txt'

        if clang_version.major > 7:
            tool_name = new_mapping_tool_name
            mapping_file = new_mapping_file_name
        else:
            tool_name = old_mapping_tool_name
            mapping_file = old_mapping_file_name

        tool_path = Path(cls.analyzer_binary()).with_name(tool_name)
        installed_dir = tool_path.parent

        if os.path.isfile(tool_path):
            return str(tool_path), mapping_file

        LOG.debug(
            "Mapping tool '%s' suggested by autodetection is not found in "
            "directory reported by Clang '%s'. Trying with version-postfixed "
            "filename...", tool_path, installed_dir)

        postfixed_tool_path = ''.join(
            [str(tool_path), '-', str(clang_version.major)])

        if os.path.isfile(postfixed_tool_path):
            return postfixed_tool_path, mapping_file

        LOG.debug(
            "Postfixed mapping tool '%s' suggested by autodetection is not "
            "found in directory reported by Clang '%s'.",
            postfixed_tool_path, installed_dir)

        return None, None

    @classmethod
    def is_ctu_capable(cls) -> bool:
        """
        Detects if the current clang is CTU compatible. Tries to autodetect
        the correct one based on clang version.
        """
        tool_path, _ = cls.ctu_mapping()

        if not tool_path:
            return False

        try:
            clang_command_output([tool_path, '-version'])
            return True
        except (subprocess.CalledProcessError, OSError):
            return False

    @classmethod
    def is_on_demand_ctu_available(cls) -> bool:
        """
        Detects if the current Clang supports on-demand parsing of ASTs for
        CTU analysis.
        """
        try:
            analyzer_options = clang_command_output([
                cls.analyzer_binary(), '-cc1', '-analyzer-config-help'])

            return 'ctu-invocation-list' in analyzer_options
        except (subprocess.CalledProcessError, OSError):
            return False

    @classmethod
    def display_progress(cls):
        """
        Return analyzer args if it is capable to display ctu progress.

        Returns None if the analyzer can not display ctu progress.
        The ctu display progress arguments depend on
        the clang analyzer version.
        """
        if not host_check.has_analyzer_config_option(
                cls.analyzer_binary(), "display-ctu-progress"):
            return None

        return [
            '-Xclang', '-analyzer-config',
            '-Xclang', 'display-ctu-progress=true']

    def is_ctu_available(self):
        """
        Check if ctu is available for the analyzer.
        If the ctu_dir is set in the config, the analyzer is capable to
        run ctu analysis.
        """
        return bool(self.config_handler.ctu_dir)

    def is_ctu_enabled(self):
        """
        Check if ctu is enabled for the analyzer.
        """
        return not self.__disable_ctu

    def disable_ctu(self):
        """
        Disable ctu even if ctu is available.
        By default it is enabled if available.
        """
        self.__disable_ctu = True

    def enable_ctu(self):
        self.__disable_ctu = False

    def add_checker_config(self, checker_cfg):
        """
        Add configuration options to specific checkers.
        checker_cfg should be a list of arguments in case of
        Clang Static Analyzer like this:
        ['-Xclang', '-analyzer-config', '-Xclang', 'checker_option=some_value']
        """

        self.__checker_configs.append(checker_cfg)

    @classmethod
    def get_analyzer_checkers(
        cls,
        alpha: bool = True,
        debug: bool = False
    ) -> List[Tuple[str, str]]:
        """
        Return the list of the supported checkers.

        Before clang9 alpha and debug checkers were printed by default. Since
        clang9 there are extra arguments to print the additional checkers.
        """
        command = [cls.analyzer_binary(), "-cc1"]

        cls.__add_plugin_load_flags(command)

        command.append("-analyzer-checker-help")

        # The clang compiler on OSX is a few
        # relases older than the open source clang release.
        # The new checker help printig flags are not available there yet.
        # If the OSX clang will be updated to based on clang v8
        # this early return can be removed.
        version_info = cls.get_binary_version()
        if version_info:
            try:
                help_page = clang_command_output([
                    cls.analyzer_binary(), "-cc1", "--help"])
            except (subprocess.CalledProcessError, OSError):
                help_page = ""

            if alpha and "-analyzer-checker-help-alpha" in help_page:
                command.append("-analyzer-checker-help-alpha")

            if debug and "-analyzer-checker-help-developer" in help_page:
                command.append("-analyzer-checker-help-developer")

        return parse_clang_help_page(command, 'CHECKERS:')

    @classmethod
    def get_checker_config(cls) -> List[analyzer_base.CheckerConfig]:
        """
        Return the list of checker config options.

        Before clang9 alpha and debug checkers were printed by default. Since
        clang9 there are extra arguments to print the additional checkers.
        """
        command = [cls.analyzer_binary(), "-cc1"]

        cls.__add_plugin_load_flags(command)

        command.append("-analyzer-checker-option-help")

        version_info = cls.get_binary_version()
        if version_info:
            try:
                help_page = clang_command_output([
                    cls.analyzer_binary(), "-cc1", "--help"])
            except (subprocess.CalledProcessError, OSError):
                help_page = ""

            if "-analyzer-checker-option-help-alpha" in help_page:
                command.append("-analyzer-checker-option-help-alpha")

            if "-analyzer-checker-option-help-developer" in help_page:
                command.append("-analyzer-checker-option-help-developer")

        result = []
        for cfg, doc in parse_clang_help_page(command, 'OPTIONS:'):
            checker, opt = cfg.split(':', 1)
            result.append(analyzer_base.CheckerConfig(checker, opt, doc))

        return result

    @classmethod
    def get_analyzer_config(cls) -> List[analyzer_base.AnalyzerConfig]:
        """Return the list of analyzer config options."""
        command = [cls.analyzer_binary(), "-cc1"]

        cls.__add_plugin_load_flags(command)

        command.append("-analyzer-config-help")

        native_config = parse_clang_help_page(command, 'OPTIONS:')
        analyzer_config_list: List[analyzer_base.AnalyzerConfig] = list(map(
            lambda cfg: analyzer_base.AnalyzerConfig(cfg[0], cfg[1], str),
            native_config))

        return analyzer_config_list + list(cls.__additional_analyzer_config)

    def post_analyze(self, result_handler):
        """
        Disabled checkers are not actually disabled during analysis, because
        they might rely on each other under the hood. The disabled checkers'
        reports are removed in this post-processing step.
        """
        try:
            if not os.path.isfile(result_handler.analyzer_result_file):
                # This check has the same race-condition reason as the
                # exception, so see its description below.
                return

            with open(result_handler.analyzer_result_file, 'rb') as f:
                plist = plistlib.load(f)
        except plistlib.InvalidFileException:
            # It may happen that a compilation database contains a build action
            # multiple times (because it is compiled for several target
            # architectures), or at least they differ in a so minor part that
            # the same .plist file belongs to them. (For further details see
            # analyzer_action_str() in ResultHandler about the strange behavior
            # of make 4.3 in its -o flag.)
            # If this happens then the analysis of the same build action is
            # analyzed in parallel several times, so the same output .plist
            # file is changed by several threads. This may result an invalid
            # .plist which fails plistlib.load(). This is not a big problem,
            # because the second thread will also execute this post-processing
            # and it happens rarely anyways. test_compile_uniqueing() fails
            # undeterministically without this.
            return

        plist['diagnostics'] = list(filter(
            lambda diag: diag['check_name'] not in self.__disabled_checkers,
            plist.get('diagnostics', [])))

        with open(result_handler.analyzer_result_file, 'wb') as f:
            plistlib.dump(plist, f)

    def construct_analyzer_cmd(self, result_handler):
        """
        Called by the analyzer method.
        Construct the analyzer command.
        """
        try:
            # Get an output file from the result handler.
            analyzer_output_file = result_handler.analyzer_result_file

            # Get the checkers list from the config_handler.
            # Checker order matters.
            config = self.config_handler

            analyzer_cmd = [ClangSA.analyzer_binary(), '--analyze',
                            # Do not warn about the unused gcc/g++ arguments.
                            '-Qunused-arguments']

            for plugin in ClangSA.analyzer_plugins():
                analyzer_cmd.extend(["-Xclang", "-plugin",
                                     "-Xclang", "checkercfg",
                                     "-Xclang", "-load",
                                     "-Xclang", plugin])

            analyzer_mode = 'plist-multi-file'
            analyzer_cmd.extend(['-Xclang',
                                 '-analyzer-output=' + analyzer_mode,
                                 '-o', analyzer_output_file])

            # Expand macros in plist output on the bug path.
            analyzer_cmd.extend(['-Xclang',
                                 '-analyzer-config',
                                 '-Xclang',
                                 'expand-macros=true'])

            # Checker configuration arguments needs to be set before
            # the checkers.
            if self.__checker_configs:
                for cfg in self.__checker_configs:
                    analyzer_cmd.extend(cfg)

            # TODO: This object has a __checker_configs attribute and the
            # corresponding functions to set it. Either those should be used
            # for checker configs coming as command line argument, or those
            # should be eliminated.
            for cfg in config.checker_config:
                analyzer_cmd.extend(
                    ['-Xclang', '-analyzer-config', '-Xclang', cfg])

            # Config handler stores which checkers are enabled or disabled.
            self.__disabled_checkers = []
            enabled_checkers = []
            for checker_name, value in config.checks().items():
                state, _ = value
                if state == CheckerState.ENABLED:
                    enabled_checkers.append(checker_name)
                elif state == CheckerState.DISABLED:
                    self.__disabled_checkers.append(checker_name)

            if enabled_checkers:
                analyzer_cmd.extend(['-Xclang',
                                     '-analyzer-checker=' +
                                     ','.join(enabled_checkers)])
            # Enable aggressive-binary-operation-simplification option.
            version_info = ClangSA.get_binary_version()
            if version_info and version_info.major >= 8:
                analyzer_cmd.extend([
                    '-Xclang',
                    '-analyzer-config',
                    '-Xclang',
                    'aggressive-binary-operation-simplification=true'])

            # Enable the z3 solver backend.
            if config.enable_z3:
                analyzer_cmd.extend(['-Xclang', '-analyzer-constraints=z3'])

            if config.enable_z3_refutation and not config.enable_z3:
                analyzer_cmd.extend(['-Xclang',
                                     '-analyzer-config',
                                     '-Xclang',
                                     'crosscheck-with-z3=true'])

            if config.ctu_dir and not self.__disable_ctu:
                analyzer_cmd.extend(
                    ['-Xclang', '-analyzer-config', '-Xclang',
                     'experimental-enable-naive-ctu-analysis=true',
                     '-Xclang', '-analyzer-config', '-Xclang',
                     'ctu-dir=' + self.get_ctu_dir()])
                ctu_display_progress = ClangSA.display_progress()
                if ctu_display_progress:
                    analyzer_cmd.extend(ctu_display_progress)

                if config.ctu_on_demand:
                    invocation_list_path = \
                        os.path.join(self.get_ctu_dir(), 'invocation-list.yml')
                    analyzer_cmd.extend(
                        ['-Xclang', '-analyzer-config', '-Xclang',
                         f'ctu-invocation-list={invocation_list_path}'
                         ])

            compile_lang = self.buildaction.lang
            if not has_flag('-x', analyzer_cmd):
                analyzer_cmd.extend(['-x', compile_lang])

            if not has_flag('--target', analyzer_cmd) and \
                    self.buildaction.target != "":
                analyzer_cmd.append(f"--target={self.buildaction.target}")

            if not has_flag('-arch', analyzer_cmd) and \
                    self.buildaction.arch != "":
                analyzer_cmd.extend(["-arch", self.buildaction.arch])

            if not has_flag('-std', analyzer_cmd) and \
                    self.buildaction.compiler_standard != "":
                analyzer_cmd.append(self.buildaction.compiler_standard)

            analyzer_cmd.extend(config.analyzer_extra_arguments)

            analyzer_cmd.extend(self.buildaction.analyzer_options)

            analyzer_cmd.extend(prepend_all(
                '-isystem' if config.add_gcc_include_dirs_with_isystem else
                '-idirafter',
                self.buildaction.compiler_includes))

            analyzer_cmd.append(self.source_file)

            return analyzer_cmd

        except Exception as ex:
            LOG.error(ex)
            return []

    def get_ctu_dir(self):
        """
        Returns the path of the ctu directory (containing the triple).
        """
        config = self.config_handler
        triple_arch = ctu_triple_arch.get_triple_arch(self.buildaction,
                                                      self.source_file,
                                                      config)
        ctu_dir = os.path.join(config.ctu_dir, triple_arch)
        return ctu_dir

    def analyzer_mentioned_file_real_path(self, mentioned_path):
        """
        PCH-based an On-demand-parsed CTU modes use different paths and file
        suffixes. PCH-based mode uses ast dump files that are suffixed with
        '.ast', and they are supposed to be under the
        '<ctu-dir>/ast/<original-full-path>'. On-demand-parsed mode uses the
        full paths of the original source files.
        """
        pch_suffix = '.ast'

        # We convert the given file path to absolute path because we suppose
        # that in the clang's output the PCH files in CTU mode are relative
        # paths.
        mentioned_path = os.path.join(self.get_ctu_dir(), mentioned_path)

        # Detect the mode based on the path.
        suffix_index = mentioned_path.rfind(pch_suffix)
        # If the file does not have the suffix, the mode is On-demand-parsed.
        # Return the original path.
        if suffix_index == -1:
            LOG.debug("Analyzer mentioned path path: '%s', "
                      "corresponding source file: '%s'",
                      mentioned_path, mentioned_path)
            return mentioned_path

        # PCH-based mode stores files with their full path structure recreated
        # under <ctu-dir>/ast.
        ctu_ast_dir = os.path.join(self.get_ctu_dir(), 'ast')

        source_path = mentioned_path[len(ctu_ast_dir):suffix_index]

        LOG.debug("Analyzer mentioned path path: '%s', "
                  "corresponding source file: '%s'",
                  mentioned_path, source_path)

        if not mentioned_path.startswith(ctu_ast_dir):
            LOG.error(
                "Mentioned path '%s' ends with suffix '%s', but does "
                "not begin with supposed ast dir '%s'.", mentioned_path,
                pch_suffix, ctu_ast_dir)

        # Strip the prefix ast directory and the suffix.
        return mentioned_path[len(ctu_ast_dir):suffix_index]

    def get_analyzer_mentioned_files(self, output):
        """
        Parse ClangSA's output to generate a list of files that were mentioned
        in the standard output or standard error.
        """
        if not output:
            return set()

        regex_for_ctu_ast_load = re.compile(
            r"CTU loaded AST file: (.*)")

        paths = set()

        for line in output.splitlines():
            match = re.match(regex_for_ctu_ast_load, line)
            if match:
                path = match.group(1)
                paths.add(self.analyzer_mentioned_file_real_path(path))

        return paths

    @classmethod
    def resolve_missing_binary(cls, configured_binary, environ):
        """
        In case of the configured binary for the analyzer is not found in the
        PATH, this method is used to find a callable binary.
        """

        LOG.debug("%s not found in path for ClangSA!", configured_binary)

        if os.path.isabs(configured_binary):
            # Do not autoresolve if the path is an absolute path as there
            # is nothing we could auto-resolve that way.
            return False

        # clang, clang-5.0, clang++, clang++-5.1, ...
        clang = env.get_binary_in_path(['clang', 'clang++'],
                                       r'^clang(\+\+)?(-\d+(\.\d+){0,2})?$',
                                       environ)

        if clang:
            LOG.debug("Using '%s' for ClangSA!", clang)
        return clang

    @classmethod
    def is_binary_version_incompatible(cls):
        """
        We support pretty much every ClangSA version.
        """
        return None

    def construct_result_handler(self, buildaction, report_output,
                                 skiplist_handler):
        """
        See base class for docs.
        """
        res_handler = ClangSAResultHandler(buildaction, report_output,
                                           self.config_handler.report_hash)

        res_handler.skiplist_handler = skiplist_handler

        return res_handler

    @classmethod
    def construct_config_handler(cls, args):

        context = analyzer_context.get_context()
        environ = context.get_env_for_bin(
            cls.analyzer_binary())

        handler = config_handler.ClangSAConfigHandler(environ)

        handler.report_hash = args.report_hash \
            if 'report_hash' in args else None

        handler.enable_z3 = 'enable_z3' in args and args.enable_z3 == 'on'

        handler.enable_z3_refutation = 'enable_z3_refutation' in args and \
            args.enable_z3_refutation == 'on'

        handler.add_gcc_include_dirs_with_isystem = \
            'add_gcc_include_dirs_with_isystem' in args and \
            args.add_gcc_include_dirs_with_isystem

        if 'ctu_phases' in args:
            handler.ctu_dir = os.path.join(args.output_path,
                                           args.ctu_dir)
            handler.ctu_on_demand = \
                'ctu_ast_mode' in args and \
                args.ctu_ast_mode == 'parse-on-demand'

        checkers = ClangSA.get_analyzer_checkers()

        try:
            cmdline_checkers = args.ordered_checkers
        except AttributeError:
            LOG.debug('No checkers were defined in the command line for %s',
                      cls.ANALYZER_NAME)
            cmdline_checkers = []

        handler.initialize_checkers(
            checkers,
            cmdline_checkers,
            'enable_all' in args and args.enable_all)

        # If --stats flag is provided then enable statistics-based checkers
        # unless explicitly disabled by the user.
        if 'stats_enabled' in args:
            # In some Clang versions, statisticsbased checkers are in the alpha
            # package (alpha.statisticsbased), and maybe not in others. Lets
            # figure out the actual checker name first.
            special_return_value = next((
                checker for checker, _ in checkers
                if SpecialReturnValueCollector.checker_analyze in checker),
                None)
            unchecked_return_value = next((
                checker for checker, _ in checkers
                if ReturnValueCollector.checker_analyze in checker),
                None)

            if special_return_value and not _is_user_disabled_checker(
                    special_return_value,
                    cmdline_checkers):
                handler.set_checker_enabled(special_return_value)

            if unchecked_return_value and not _is_user_disabled_checker(
                    unchecked_return_value,
                    cmdline_checkers):
                handler.set_checker_enabled(unchecked_return_value)

        # Statistics collector checkers must be explicitly disabled as they
        # trash the output. These checkers are executed in a preceding analysis
        # phase.
        handler.set_checker_enabled(
            SpecialReturnValueCollector.checker_collect, False)

        handler.set_checker_enabled(
            ReturnValueCollector.checker_collect, False)

        handler.checker_config = []

        # TODO: This extra "isinstance" check is needed for
        # CodeChecker checkers --checker-config. This command also runs
        # this function in order to construct a config handler.
        if 'checker_config' in args and isinstance(args.checker_config, list):
            for cfg in args.checker_config:
                if cfg.analyzer == cls.ANALYZER_NAME:
                    handler.checker_config.append(
                        f"{cfg.checker}:{cfg.option}={cfg.value}")

        # TODO: This extra "isinstance" check is needed for
        # CodeChecker analyzers --analyzer-config. This command also runs
        # this function in order to construct a config handler.
        if 'analyzer_config' in args and \
                isinstance(args.analyzer_config, list):
            for cfg in args.analyzer_config:
                # TODO: The analyzer plugin should get only its own analyzer
                # config options from outside.
                if cfg.analyzer != cls.ANALYZER_NAME:
                    continue

                if cfg.option == 'cc-verbatim-args-file':
                    try:
                        handler.analyzer_extra_arguments = \
                            util.load_args_from_file(cfg.value)
                    except FileNotFoundError:
                        LOG.error(f"File not found: {cfg.value}")
                        sys.exit(1)
                else:
                    handler.checker_config.append(f"{cfg.option}={cfg.value}")

        return handler