llvm/libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/generic_category.pass.cpp

//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

// <system_error>

// class error_category

// const error_category& generic_category();

#include <system_error>
#include <cassert>
#include <string>
#include <cerrno>

#include "test_macros.h"

// See https://llvm.org/D65667
struct StaticInit {
    const std::error_category* ec;
    ~StaticInit() {
        std::string str = ec->name();
        assert(str == "generic") ;
    }
};
static StaticInit foo;

int main(int, char**)
{
    {
        const std::error_category& e_cat1 = std::generic_category();
        std::string m1 = e_cat1.name();
        assert(m1 == "generic");
    }

    // Test the result of message(int cond) when given a bad error condition
    {
        errno = E2BIG; // something that message will never generate
        const std::error_category& e_cat1 = std::generic_category();
        const std::string msg = e_cat1.message(-1);
        // Exact message format varies by platform.  We can't detect
        // some of these (Musl in particular) using the preprocessor,
        // so accept a few sensible messages.  Newlib unfortunately
        // responds with an empty message, which we probably want to
        // treat as a failure code otherwise, but we can detect that
        // with the preprocessor.
#if defined(_NEWLIB_VERSION)
        const bool is_newlib = true;
#else
        const bool is_newlib = false;
#endif
        (void)is_newlib;
        LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0       // AIX
                      || msg.rfind("No error information", 0) == 0 // Musl
                      || msg.rfind("Unknown error", 0) == 0        // Glibc
                      || (is_newlib && msg.empty()));
        assert(errno == E2BIG);
    }

    {
        foo.ec = &std::generic_category();
        std::string m2 = foo.ec->name();
        assert(m2 == "generic");
    }

    return 0;
}