TheRock/rocm-libraries/projects/miopen/src/env.cpp

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#include <miopen/env.hpp>

#ifndef _WIN32
#include <cstdlib>
#endif

#include <optional>
#include <string>
#include <string_view>

#ifdef _WIN32
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <Windows.h>
#endif

namespace miopen::env {

std::optional<std::string> getEnvironmentVariable(std::string_view name)
{
#ifdef _WIN32
    auto required_size = GetEnvironmentVariable(name.data(), nullptr, 0);
    if(required_size == 0) // usually ERROR_ENVVAR_NOT_FOUND
    {
        return std::nullopt;
    }
    // requires size to hold the string and its terminating null character.
    std::string value(required_size - 1, 0);
    GetEnvironmentVariable(name.data(), value.data(), required_size);
    return {value};
#else
    // NOLINTNEXTLINE(concurrency-mt-unsafe)
    auto value = std::getenv(name.data());
    return value == nullptr ? std::nullopt : std::make_optional<std::string>(value);
#endif
}

} // namespace miopen::env