/*
 * This source code is released into the public domain.
 */

module;

#include <expected>
#include <string>

#include "nihil.hh"

export module nihil.posix:fexecv;

import nihil.error;
import :argv;
import :executor;
import :fd;

namespace nihil {

#ifdef NIHIL_HAVE_FEXECVE

/*
 * fexecv: use a file descriptor and an argument vector to call ::fexecve().
 * This is the lowest-level executor which all others are implemented
 * in terms of (if it's available).
 *
 * TODO: Should have a way to pass the environment (envp).
 */
export struct fexecv final {
	using tag = exec_tag;

	fexecv(fd &&execfd, argv &&args) noexcept;

	[[nodiscard]] auto exec(this fexecv &self)
		-> std::expected<void, error>;

	// Movable
	fexecv(fexecv &&) noexcept;
	auto operator=(this fexecv &, fexecv &&) noexcept -> fexecv&;

	// Not copyable (because we hold the open fd object)
	fexecv(fexecv const &) = delete;
	auto operator=(this fexecv &, fexecv const &) -> fexecv& = delete;

private:
	fd	m_execfd;
	argv	m_args;
};

#endif	// NIHIL_HAVE_FEXECVE

} // namespace nihil