libcxx/test/features.py

# ===----------------------------------------------------------------------===##
#
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#
# ===----------------------------------------------------------------------===##

from libcxx.test.dsl import *
from lit.BooleanExpression import BooleanExpression
import re
import shutil
import subprocess
import sys

_isClang = lambda cfg: "__clang__" in compilerMacros(cfg) and "__apple_build_version__" not in compilerMacros(cfg)
_isAppleClang = lambda cfg: "__apple_build_version__" in compilerMacros(cfg)
_isGCC = lambda cfg: "__GNUC__" in compilerMacros(cfg) and "__clang__" not in compilerMacros(cfg)
_isMSVC = lambda cfg: "_MSC_VER" in compilerMacros(cfg)
_msvcVersion = lambda cfg: (int(compilerMacros(cfg)["_MSC_VER"]) // 100, int(compilerMacros(cfg)["_MSC_VER"]) % 100)


def _getSuitableClangTidy(cfg):
    try:
        # If we didn't build the libcxx-tidy plugin via CMake, we can't run the clang-tidy tests.
        if runScriptExitCode(cfg, ["stat %{test-tools}/clang_tidy_checks/libcxx-tidy.plugin"]) != 0:
            return None

        # TODO MODULES require ToT due module specific fixes.
        if runScriptExitCode(cfg, ['clang-tidy-17 --version']) == 0:
          return 'clang-tidy-17'

        # TODO This should be the last stable release.
        # LLVM RELEASE bump to latest stable version
        if runScriptExitCode(cfg, ["clang-tidy-16 --version"]) == 0:
            return "clang-tidy-16"

        # LLVM RELEASE bump version
        if int(re.search("[0-9]+", commandOutput(cfg, ["clang-tidy --version"])).group()) >= 16:
            return "clang-tidy"

    except ConfigurationRuntimeError:
        return None


def _getAndroidDeviceApi(cfg):
    return int(
        programOutput(
            cfg,
            r"""
                #include <android/api-level.h>
                #include <stdio.h>
                int main() {
                    printf("%d\n", android_get_device_api_level());
                    return 0;
                }
            """,
        )
    )

# Lit features are evaluated in order. Some checks may require the compiler detection to have
# run first in order to work properly.
DEFAULT_FEATURES = [
    Feature(name="apple-clang", when=_isAppleClang),
    Feature(
        name=lambda cfg: "apple-clang-{__clang_major__}".format(**compilerMacros(cfg)),
        when=_isAppleClang,
    ),
    Feature(
        name=lambda cfg: "apple-clang-{__clang_major__}.{__clang_minor__}".format(**compilerMacros(cfg)),
        when=_isAppleClang,
    ),
    Feature(
        name=lambda cfg: "apple-clang-{__clang_major__}.{__clang_minor__}.{__clang_patchlevel__}".format(**compilerMacros(cfg)),
        when=_isAppleClang,
    ),
    Feature(name="clang", when=_isClang),
    Feature(
        name=lambda cfg: "clang-{__clang_major__}".format(**compilerMacros(cfg)),
        when=_isClang,
    ),
    Feature(
        name=lambda cfg: "clang-{__clang_major__}.{__clang_minor__}".format(**compilerMacros(cfg)),
        when=_isClang,
    ),
    Feature(
        name=lambda cfg: "clang-{__clang_major__}.{__clang_minor__}.{__clang_patchlevel__}".format(**compilerMacros(cfg)),
        when=_isClang,
    ),
    # Note: Due to a GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104760), we must disable deprecation warnings
    #       on GCC or spurious diagnostics are issued.
    #
    # TODO:
    # - Enable -Wplacement-new with GCC.
    # - Enable -Wclass-memaccess with GCC.
    Feature(
        name="gcc",
        when=_isGCC,
        actions=[
            AddCompileFlag("-D_LIBCPP_DISABLE_DEPRECATION_WARNINGS"),
            AddCompileFlag("-Wno-placement-new"),
            AddCompileFlag("-Wno-class-memaccess"),
            AddFeature("GCC-ALWAYS_INLINE-FIXME"),
        ],
    ),
    Feature(
        name=lambda cfg: "gcc-{__GNUC__}".format(**compilerMacros(cfg)), when=_isGCC
    ),
    Feature(
        name=lambda cfg: "gcc-{__GNUC__}.{__GNUC_MINOR__}".format(**compilerMacros(cfg)),
        when=_isGCC,
    ),
    Feature(
        name=lambda cfg: "gcc-{__GNUC__}.{__GNUC_MINOR__}.{__GNUC_PATCHLEVEL__}".format(**compilerMacros(cfg)),
        when=_isGCC,
    ),
    Feature(name="msvc", when=_isMSVC),
    Feature(name=lambda cfg: "msvc-{}".format(*_msvcVersion(cfg)), when=_isMSVC),
    Feature(name=lambda cfg: "msvc-{}.{}".format(*_msvcVersion(cfg)), when=_isMSVC),

    Feature(
        name="thread-safety",
        when=lambda cfg: hasCompileFlag(cfg, "-Werror=thread-safety"),
        actions=[AddCompileFlag("-Werror=thread-safety")],
    ),
    Feature(
        name="diagnose-if-support",
        when=lambda cfg: hasCompileFlag(cfg, "-Wuser-defined-warnings"),
        actions=[AddCompileFlag("-Wuser-defined-warnings")],
    ),
    # Tests to validate whether the compiler has a way to set the maximum number
    # of steps during constant evaluation. Since the flag differs per compiler
    # store the "valid" flag as a feature. This allows passing the proper compile
    # flag to the compiler:
    # // ADDITIONAL_COMPILE_FLAGS(has-fconstexpr-steps): -fconstexpr-steps=12345678
    # // ADDITIONAL_COMPILE_FLAGS(has-fconstexpr-ops-limit): -fconstexpr-ops-limit=12345678
    Feature(
        name="has-fconstexpr-steps",
        when=lambda cfg: hasCompileFlag(cfg, "-fconstexpr-steps=1"),
    ),
    Feature(
        name="has-fconstexpr-ops-limit",
        when=lambda cfg: hasCompileFlag(cfg, "-fconstexpr-ops-limit=1"),
    ),
    Feature(name="has-fblocks", when=lambda cfg: hasCompileFlag(cfg, "-fblocks")),
    Feature(
        name="-fsized-deallocation",
        when=lambda cfg: hasCompileFlag(cfg, "-fsized-deallocation"),
    ),
    Feature(
        name="-faligned-allocation",
        when=lambda cfg: hasCompileFlag(cfg, "-faligned-allocation"),
    ),
    Feature(
        name="fdelayed-template-parsing",
        when=lambda cfg: hasCompileFlag(cfg, "-fdelayed-template-parsing"),
    ),
    Feature(
        name="has-fobjc-arc",
        when=lambda cfg: hasCompileFlag(cfg, "-xobjective-c++ -fobjc-arc")
        and sys.platform.lower().strip() == "darwin",
    ),  # TODO: this doesn't handle cross-compiling to Apple platforms.
    Feature(
        name="objective-c++",
        when=lambda cfg: hasCompileFlag(cfg, "-xobjective-c++ -fobjc-arc"),
    ),
    Feature(
        name="verify-support",
        when=lambda cfg: hasCompileFlag(cfg, "-Xclang -verify-ignore-unexpected"),
    ),
    Feature(
        name="add-latomic-workaround",  # https://github.com/llvm/llvm-project/issues/73361
        when=lambda cfg: sourceBuilds(
            cfg, "int main(int, char**) { return 0; }", ["-latomic"]
        ),
        actions=[AddLinkFlag("-latomic")],
    ),
    Feature(
        name="non-lockfree-atomics",
        when=lambda cfg: sourceBuilds(
            cfg,
            """
            #include <atomic>
            struct Large { int storage[100]; };
            std::atomic<Large> x;
            int main(int, char**) { (void)x.load(); return 0; }
          """,
        ),
    ),
    Feature(
        name="has-64-bit-atomics",
        when=lambda cfg: sourceBuilds(
            cfg,
            """
            #include <atomic>
            std::atomic_uint64_t x;
            int main(int, char**) { (void)x.load(); return 0; }
          """,
        ),
    ),
    # TODO: Remove this feature once compiler-rt includes __atomic_is_lockfree()
    # on all supported platforms.
    Feature(
        name="is-lockfree-runtime-function",
        when=lambda cfg: sourceBuilds(
            cfg,
            """
            #include <atomic>
            struct Large { int storage[100]; };
            std::atomic<Large> x;
            int main(int, char**) { return x.is_lock_free(); }
          """,
        ),
    ),
    # Check for a Windows UCRT bug (fixed in UCRT/Windows 10.0.20348.0):
    # https://developercommunity.visualstudio.com/t/utf-8-locales-break-ctype-functions-for-wchar-type/1653678
    Feature(
        name="win32-broken-utf8-wchar-ctype",
        when=lambda cfg: not "_LIBCPP_HAS_NO_LOCALIZATION" in compilerMacros(cfg)
        and "_WIN32" in compilerMacros(cfg)
        and not programSucceeds(
            cfg,
            """
            #include <locale.h>
            #include <wctype.h>
            int main(int, char**) {
              setlocale(LC_ALL, "en_US.UTF-8");
              return towlower(L'\\xDA') != L'\\xFA';
            }
          """,
        ),
    ),
    # Check for a Windows UCRT bug (fixed in UCRT/Windows 10.0.19041.0).
    # https://developercommunity.visualstudio.com/t/printf-formatting-with-g-outputs-too/1660837
    Feature(
        name="win32-broken-printf-g-precision",
        when=lambda cfg: "_WIN32" in compilerMacros(cfg)
        and not programSucceeds(
            cfg,
            """
            #include <stdio.h>
            #include <string.h>
            int main(int, char**) {
              char buf[100];
              snprintf(buf, sizeof(buf), "%#.*g", 0, 0.0);
              return strcmp(buf, "0.");
            }
          """,
        ),
    ),
    # Check for Glibc < 2.27, where the ru_RU.UTF-8 locale had
    # mon_decimal_point == ".", which our tests don't handle.
    Feature(
        name="glibc-old-ru_RU-decimal-point",
        when=lambda cfg: not "_LIBCPP_HAS_NO_LOCALIZATION" in compilerMacros(cfg)
        and not programSucceeds(
            cfg,
            """
            #include <locale.h>
            #include <string.h>
            int main(int, char**) {
              setlocale(LC_ALL, "ru_RU.UTF-8");
              return strcmp(localeconv()->mon_decimal_point, ",");
            }
          """,
        ),
    ),
    Feature(
        name="has-unix-headers",
        when=lambda cfg: sourceBuilds(
            cfg,
            """
            #include <unistd.h>
            #include <sys/wait.h>
            int main(int, char**) {
              int fd[2];
              return pipe(fd);
            }
          """,
        ),
    ),
    # Whether Bash can run on the executor.
    # This is not always the case, for example when running on embedded systems.
    #
    # For the corner case of bash existing, but it being missing in the path
    # set in %{exec} as "--env PATH=one-single-dir", the executor does find
    # and executes bash, but bash then can't find any other common shell
    # utilities. Test executing "bash -c 'bash --version'" to see if bash
    # manages to find binaries to execute.
    Feature(
        name="executor-has-no-bash",
        when=lambda cfg: runScriptExitCode(cfg, ["%{exec} bash -c 'bash --version'"]) != 0,
    ),
    Feature(
        name="has-clang-tidy",
        when=lambda cfg: _getSuitableClangTidy(cfg) is not None,
        actions=[
            AddSubstitution("%{clang-tidy}", lambda cfg: _getSuitableClangTidy(cfg))
        ],
    ),
]

# Deduce and add the test features that that are implied by the #defines in
# the <__config_site> header.
#
# For each macro of the form `_LIBCPP_XXX_YYY_ZZZ` defined below that
# is defined after including <__config_site>, add a Lit feature called
# `libcpp-xxx-yyy-zzz`. When a macro is defined to a specific value
# (e.g. `_LIBCPP_ABI_VERSION=2`), the feature is `libcpp-xxx-yyy-zzz=<value>`.
#
# Note that features that are more strongly tied to libc++ are named libcpp-foo,
# while features that are more general in nature are not prefixed with 'libcpp-'.
macros = {
    "_LIBCPP_HAS_NO_MONOTONIC_CLOCK": "no-monotonic-clock",
    "_LIBCPP_HAS_NO_THREADS": "no-threads",
    "_LIBCPP_HAS_THREAD_API_EXTERNAL": "libcpp-has-thread-api-external",
    "_LIBCPP_HAS_THREAD_API_PTHREAD": "libcpp-has-thread-api-pthread",
    "_LIBCPP_NO_VCRUNTIME": "libcpp-no-vcruntime",
    "_LIBCPP_ABI_VERSION": "libcpp-abi-version",
    "_LIBCPP_ABI_BOUNDED_ITERATORS": "libcpp-has-abi-bounded-iterators",
    "_LIBCPP_HAS_NO_FILESYSTEM": "no-filesystem",
    "_LIBCPP_HAS_NO_RANDOM_DEVICE": "no-random-device",
    "_LIBCPP_HAS_NO_LOCALIZATION": "no-localization",
    "_LIBCPP_HAS_NO_WIDE_CHARACTERS": "no-wide-characters",
    "_LIBCPP_HAS_NO_TIME_ZONE_DATABASE": "no-tzdb",
    "_LIBCPP_HAS_NO_UNICODE": "libcpp-has-no-unicode",
    "_LIBCPP_HAS_NO_STD_MODULES":  "libcpp-has-no-std-modules",
    "_LIBCPP_PSTL_CPU_BACKEND_LIBDISPATCH": "libcpp-pstl-cpu-backend-libdispatch",
}
for macro, feature in macros.items():
    DEFAULT_FEATURES.append(
        Feature(
            name=lambda cfg, m=macro, f=feature: f + ("={}".format(compilerMacros(cfg)[m]) if compilerMacros(cfg)[m] else ""),
            when=lambda cfg, m=macro: m in compilerMacros(cfg),
        )
    )


# Mapping from canonical locale names (used in the tests) to possible locale
# names on various systems. Each locale is considered supported if any of the
# alternative names is supported.
locales = {
    "en_US.UTF-8": ["en_US.UTF-8", "en_US.utf8", "English_United States.1252"],
    "fr_FR.UTF-8": ["fr_FR.UTF-8", "fr_FR.utf8", "French_France.1252"],
    "ja_JP.UTF-8": ["ja_JP.UTF-8", "ja_JP.utf8", "Japanese_Japan.923"],
    "ru_RU.UTF-8": ["ru_RU.UTF-8", "ru_RU.utf8", "Russian_Russia.1251"],
    "zh_CN.UTF-8": ["zh_CN.UTF-8", "zh_CN.utf8", "Chinese_China.936"],
    "fr_CA.ISO8859-1": ["fr_CA.ISO8859-1", "French_Canada.1252"],
    "cs_CZ.ISO8859-2": ["cs_CZ.ISO8859-2", "Czech_Czech Republic.1250"],
}
for locale, alts in locales.items():
    # Note: Using alts directly in the lambda body here will bind it to the value at the
    # end of the loop. Assigning it to a default argument works around this issue.
    DEFAULT_FEATURES.append(
        Feature(
            name="locale.{}".format(locale),
            when=lambda cfg, alts=alts: hasAnyLocale(cfg, alts),
        )
    )


# Add features representing the target platform name: darwin, linux, windows, etc...
DEFAULT_FEATURES += [
    Feature(name="darwin", when=lambda cfg: "__APPLE__" in compilerMacros(cfg)),
    Feature(name="windows", when=lambda cfg: "_WIN32" in compilerMacros(cfg)),
    Feature(
        name="windows-dll",
        when=lambda cfg: "_WIN32" in compilerMacros(cfg)
        and sourceBuilds(
            cfg,
            """
            #include <iostream>
            int main(int, char**) { return 0; }
          """,
        )
        and programSucceeds(
            cfg,
            """
            #include <iostream>
            #include <windows.h>
            #include <winnt.h>
            int main(int, char**) {
              // Get a pointer to a data member that gets linked from the C++
              // library. This must be a data member (functions can get
              // thunk inside the calling executable), and must not be
              // something that is defined inline in headers.
              void *ptr = &std::cout;
              // Get a handle to the current main executable.
              void *exe = GetModuleHandle(NULL);
              // The handle points at the PE image header. Navigate through
              // the header structure to find the size of the PE image (the
              // executable).
              PIMAGE_DOS_HEADER dosheader = (PIMAGE_DOS_HEADER)exe;
              PIMAGE_NT_HEADERS ntheader = (PIMAGE_NT_HEADERS)((BYTE *)dosheader + dosheader->e_lfanew);
              PIMAGE_OPTIONAL_HEADER peheader = &ntheader->OptionalHeader;
              void *exeend = (BYTE*)exe + peheader->SizeOfImage;
              // Check if the tested pointer - the data symbol from the
              // C++ library - is located within the exe.
              if (ptr >= exe && ptr <= exeend)
                return 1;
              // Return success if it was outside of the executable, i.e.
              // loaded from a DLL.
              return 0;
            }
          """,
        ),
        actions=[AddCompileFlag("-DTEST_WINDOWS_DLL")],
    ),
    Feature(name="linux", when=lambda cfg: "__linux__" in compilerMacros(cfg)),
    Feature(name="android", when=lambda cfg: "__ANDROID__" in compilerMacros(cfg)),
    Feature(
        name=lambda cfg: "android-device-api={}".format(_getAndroidDeviceApi(cfg)),
        when=lambda cfg: "__ANDROID__" in compilerMacros(cfg),
    ),
    Feature(
        name="LIBCXX-ANDROID-FIXME",
        when=lambda cfg: "__ANDROID__" in compilerMacros(cfg),
    ),
    Feature(name="netbsd", when=lambda cfg: "__NetBSD__" in compilerMacros(cfg)),
    Feature(name="freebsd", when=lambda cfg: "__FreeBSD__" in compilerMacros(cfg)),
    Feature(
        name="LIBCXX-FREEBSD-FIXME",
        when=lambda cfg: "__FreeBSD__" in compilerMacros(cfg),
    ),
    Feature(
        name="LIBCXX-PICOLIBC-FIXME",
        when=lambda cfg: sourceBuilds(
            cfg,
            """
            #include <string.h>
            #ifndef __PICOLIBC__
            #error not picolibc
            #endif
            int main(int, char**) { return 0; }
          """,
        ),
    ),
]

# Add features representing the build host platform name.
# The build host could differ from the target platform for cross-compilation.
DEFAULT_FEATURES += [
    Feature(name="buildhost={}".format(sys.platform.lower().strip())),
    # sys.platform can often be represented by a "sub-system", such as 'win32', 'cygwin', 'mingw', freebsd13 & etc.
    # We define a consolidated feature on a few platforms.
    Feature(
        name="buildhost=windows",
        when=lambda cfg: platform.system().lower().startswith("windows"),
    ),
    Feature(
        name="buildhost=freebsd",
        when=lambda cfg: platform.system().lower().startswith("freebsd"),
    ),
    Feature(
        name="buildhost=aix",
        when=lambda cfg: platform.system().lower().startswith("aix"),
    ),
]

# Detect whether GDB is on the system, has Python scripting and supports
# adding breakpoint commands. If so add a substitution to access it.
def check_gdb(cfg):
    gdb_path = shutil.which("gdb")
    if gdb_path is None:
        return False

    # Check that we can set breakpoint commands, which was added in 8.3.
    # Using the quit command here means that gdb itself exits, not just
    # the "python <...>" command.
    test_src = """\
try:
  gdb.Breakpoint(\"main\").commands=\"foo\"
except AttributeError:
  gdb.execute(\"quit 1\")
gdb.execute(\"quit\")"""

    try:
        stdout = subprocess.check_output(
            [gdb_path, "-ex", "python " + test_src, "--batch"],
            stderr=subprocess.DEVNULL,
            universal_newlines=True,
        )
    except subprocess.CalledProcessError:
        # We can't set breakpoint commands
        return False

    # Check we actually ran the Python
    return not "Python scripting is not supported" in stdout


DEFAULT_FEATURES += [
    Feature(
        name="host-has-gdb-with-python",
        when=check_gdb,
        actions=[AddSubstitution("%{gdb}", lambda cfg: shutil.which("gdb"))],
    )
]

# Define features for back-deployment testing.
#
# These features can be used to XFAIL tests that fail when deployed on (or compiled
# for) an older system. For example, if a test exhibits a bug in the libc on a
# particular system version, or if it uses a symbol that is not available on an
# older version of the dylib, it can be marked as XFAIL with these features.
#
# It is sometimes useful to check that a test fails specifically when compiled for a
# given deployment target. For example, this is the case when testing availability
# markup, where we want to make sure that using the annotated facility on a deployment
# target that doesn't support it will fail at compile time, not at runtime. This can
# be achieved by creating a `.verify.cpp` test that checks for the right errors, and
# mark that test as requiring `stdlib=<vendor>-libc++ && target=<target>`.
DEFAULT_FEATURES += [
    # Tests that require std::to_chars(floating-point) in the built library
    Feature(
        name="availability-fp_to_chars-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            "stdlib=apple-libc++ && target={{.+}}-apple-macosx{{(10.13|10.14|10.15|11.0|12.0|13.0)(.0)?}}",
            cfg.available_features,
        ),
    ),
    # Tests that require https://wg21.link/P0482 support in the built library
    Feature(
        name="availability-char8_t_support-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            "stdlib=apple-libc++ && target={{.+}}-apple-macosx{{(10.13|10.14|10.15|11.0)(.0)?}}",
            cfg.available_features,
        ),
    ),
    # Tests that require __libcpp_verbose_abort support in the built library
    Feature(
        name="availability-verbose_abort-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            "stdlib=apple-libc++ && target={{.+}}-apple-macosx{{(10.13|10.14|10.15|11.0|12.0|13.0)(.0)?}}",
            cfg.available_features,
        ),
    ),
    # Tests that require std::pmr support in the built library
    Feature(
        name="availability-pmr-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            "stdlib=apple-libc++ && target={{.+}}-apple-macosx{{(10.13|10.14|10.15|11.0|12.0|13.0)(.0)?}}",
            cfg.available_features,
        ),
    ),
    # Tests that require std::filesystem support in the built library
    Feature(
        name="availability-filesystem-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            "stdlib=apple-libc++ && target={{.+}}-apple-macosx10.{{(13|14)(.0)?}}",
            cfg.available_features,
        ),
    ),
    # Tests that require the C++20 synchronization library (P1135R6 implemented by https://llvm.org/D68480) in the built library
    Feature(
        name="availability-synchronization_library-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            "stdlib=apple-libc++ && target={{.+}}-apple-macosx10.{{(13|14|15)(.0)?}}",
            cfg.available_features,
        ),
    ),
    # Tests that require time zone database support in the built library
    Feature(
        name="availability-tzdb-missing",
        when=lambda cfg: BooleanExpression.evaluate(
            # TODO(ldionne) Please provide the correct value.
            "(stdlib=apple-libc++ && target={{.+}}-apple-macosx{{(10.13|10.14|10.15|11.0|12.0|13.0)(.0)?}})",
            cfg.available_features,
        ),
    ),
    # Tests that require 64-bit architecture
    Feature(
        name="32-bit-pointer",
        when=lambda cfg: sourceBuilds(
            cfg,
            """
            int main(int, char**) {
              static_assert(sizeof(void *) == 4);
            }
          """,
        ),
    ),
]