libc-test/build.rs

#![deny(warnings)]

extern crate ctest;

use std::env;

fn main() {
    let target = env::var("TARGET").unwrap();
    let aarch64 = target.contains("aarch64");
    let i686 = target.contains("i686");
    let x86_64 = target.contains("x86_64");
    let x32 = target.ends_with("gnux32");
    let windows = target.contains("windows");
    let mingw = target.contains("windows-gnu");
    let linux = target.contains("unknown-linux");
    let android = target.contains("android");
    let apple = target.contains("apple");
    let ios = target.contains("apple-ios");
    let emscripten = target.contains("asm");
    let musl = target.contains("musl") || emscripten;
    let uclibc = target.contains("uclibc");
    let freebsd = target.contains("freebsd");
    let dragonfly = target.contains("dragonfly");
    let mips = target.contains("mips");
    let netbsd = target.contains("netbsd");
    let openbsd = target.contains("openbsd");
    let rumprun = target.contains("rumprun");
    let solaris = target.contains("solaris");
    let cloudabi = target.contains("cloudabi");
    let redox = target.contains("redox");
    let bsdlike = freebsd || apple || netbsd || openbsd || dragonfly;
    let mut cfg = ctest::TestGenerator::new();

    // Pull in extra goodies
    if linux || android || emscripten {
        cfg.define("_GNU_SOURCE", None);
    } else if netbsd {
        cfg.define("_NETBSD_SOURCE", Some("1"));
    } else if apple {
        cfg.define("__APPLE_USE_RFC_3542", None);
    } else if windows {
        cfg.define("_WIN32_WINNT", Some("0x8000"));
    } else if solaris {
        cfg.define("_XOPEN_SOURCE", Some("700"));
        cfg.define("__EXTENSIONS__", None);
        cfg.define("_LCONV_C99", None);
    } else if freebsd {
        cfg.define("_WITH_GETLINE", None);
    }

    // Android doesn't actually have in_port_t but it's much easier if we
    // provide one for us to test against
    if android {
        cfg.define("in_port_t", Some("uint16_t"));
    }

    cfg.header("errno.h")
        .header("fcntl.h")
        .header("limits.h")
        .header("locale.h")
        .header("stddef.h")
        .header("stdint.h")
        .header("stdio.h")
        .header("stdlib.h")
        .header("sys/stat.h")
        .header("sys/types.h")
        .header("time.h")
        .header("wchar.h");

    if windows {
        cfg.header("winsock2.h"); // must be before windows.h

        cfg.header("direct.h");
        cfg.header("io.h");
        cfg.header("sys/utime.h");
        cfg.header("windows.h");
        cfg.header("process.h");
        cfg.header("ws2ipdef.h");

        if target.contains("gnu") {
            cfg.header("ws2tcpip.h");
        }
    } else {
        cfg.flag("-Wno-deprecated-declarations");

        cfg.header("ctype.h");
        cfg.header("dirent.h");
        if openbsd {
            cfg.header("sys/socket.h");
        }
        cfg.header("net/if.h");
        if !ios {
            cfg.header("net/route.h");
            cfg.header("net/if_arp.h");
        }
        cfg.header("netdb.h");
        cfg.header("netinet/in.h");
        cfg.header("netinet/ip.h");
        cfg.header("netinet/tcp.h");
        cfg.header("netinet/udp.h");
        cfg.header("resolv.h");
        cfg.header("pthread.h");
        cfg.header("dlfcn.h");
        cfg.header("signal.h");
        cfg.header("string.h");
        cfg.header("sys/file.h");
        cfg.header("sys/ioctl.h");
        cfg.header("sys/mman.h");
        cfg.header("sys/resource.h");
        cfg.header("sys/socket.h");
        if linux && !musl {
            cfg.header("linux/if.h");
            cfg.header("sys/auxv.h");
        }
        cfg.header("sys/time.h");
        cfg.header("sys/un.h");
        cfg.header("sys/wait.h");
        cfg.header("unistd.h");
        cfg.header("utime.h");
        cfg.header("pwd.h");
        cfg.header("grp.h");
        cfg.header("sys/utsname.h");
        if !solaris && !ios {
            cfg.header("sys/ptrace.h");
        }
        cfg.header("sys/mount.h");
        cfg.header("sys/uio.h");
        cfg.header("sched.h");
        cfg.header("termios.h");
        cfg.header("poll.h");
        cfg.header("syslog.h");
        cfg.header("semaphore.h");
        cfg.header("sys/statvfs.h");
        cfg.header("sys/times.h");
    }

    if android {
        if !aarch64 && !x86_64 {
            // time64_t is not define for aarch64 and x86_64
            // If included it will generate the error 'Your time_t is already 64-bit'
            cfg.header("time64.h");
        }
        cfg.header("arpa/inet.h");
        cfg.header("xlocale.h");
        cfg.header("utmp.h");
        cfg.header("ifaddrs.h");
        if i686 || x86_64 {
            cfg.header("sys/reg.h");
        }
    } else if !windows {
        cfg.header("glob.h");
        cfg.header("ifaddrs.h");
        cfg.header("langinfo.h");

        if !openbsd && !freebsd && !dragonfly && !solaris {
            cfg.header("sys/quota.h");
        }

        if !musl && !x32 && !solaris {
            cfg.header("sys/sysctl.h");
        }

        if !musl && !uclibc {
            if !netbsd && !openbsd && !uclibc {
                cfg.header("execinfo.h");
            }

            if openbsd {
                cfg.header("utmp.h");
            } else {
                cfg.header("utmpx.h");
            }
        }
    }

    if apple {
        cfg.header("spawn.h");
        cfg.header("mach-o/dyld.h");
        cfg.header("mach/mach_time.h");
        cfg.header("malloc/malloc.h");
        cfg.header("util.h");
        cfg.header("xlocale.h");
        cfg.header("sys/xattr.h");
        if target.starts_with("x86") && !ios {
            cfg.header("crt_externs.h");
        }
        cfg.header("netinet/in.h");
        cfg.header("sys/ipc.h");
        cfg.header("sys/shm.h");

        if !ios {
            cfg.header("sys/sys_domain.h");
            cfg.header("net/if_utun.h");
            cfg.header("net/bpf.h");
            cfg.header("net/route.h");
            cfg.header("netinet/if_ether.h");
            cfg.header("sys/proc_info.h");
            cfg.header("sys/kern_control.h");
        }
    }

    if bsdlike {
        cfg.header("sys/event.h");
        cfg.header("net/if_dl.h");
        if freebsd {
            cfg.header("net/bpf.h");
            cfg.header("libutil.h");
        } else {
            cfg.header("util.h");
        }
    }

    if linux || emscripten {
        cfg.header("mntent.h");
        cfg.header("mqueue.h");
        cfg.header("ucontext.h");
        if !uclibc {
            // optionally included in uclibc
            cfg.header("sys/xattr.h");
        }
        cfg.header("sys/ipc.h");
        cfg.header("sys/sem.h");
        cfg.header("sys/msg.h");
        cfg.header("sys/shm.h");
        cfg.header("sys/user.h");
        cfg.header("sys/timerfd.h");
        cfg.header("shadow.h");
        if !emscripten {
            cfg.header("linux/input.h");
            cfg.header("linux/falloc.h");
        }
        if x86_64 {
            cfg.header("sys/io.h");
        }
        if i686 || x86_64 {
            cfg.header("sys/reg.h");
        }
    }

    if linux || android || emscripten {
        cfg.header("malloc.h");
        cfg.header("net/ethernet.h");
        cfg.header("netpacket/packet.h");
        cfg.header("sched.h");
        cfg.header("sys/epoll.h");
        cfg.header("sys/eventfd.h");
        cfg.header("sys/prctl.h");
        cfg.header("sys/sendfile.h");
        cfg.header("sys/signalfd.h");
        cfg.header("sys/vfs.h");
        cfg.header("sys/syscall.h");
        cfg.header("sys/personality.h");
        cfg.header("sys/swap.h");
        cfg.header("pty.h");
        if !uclibc {
            cfg.header("sys/sysinfo.h");
        }
        cfg.header("sys/reboot.h");
        if !emscripten {
            cfg.header("linux/sockios.h");
            cfg.header("linux/netlink.h");
            cfg.header("linux/genetlink.h");
            cfg.header("linux/netfilter_ipv4.h");
            cfg.header("linux/netfilter_ipv6.h");
            cfg.header("linux/fs.h");
        }
        if !musl {
            cfg.header("asm/mman.h");
            cfg.header("linux/magic.h");
            cfg.header("linux/reboot.h");
            cfg.header("linux/netfilter/nf_tables.h");

            if !mips {
                cfg.header("linux/quota.h");
            }
        }
    }
    if solaris {
        cfg.header("sys/epoll.h");
    }

    if linux || android {
        cfg.header("sys/fsuid.h");
        cfg.header("linux/module.h");
        cfg.header("linux/seccomp.h");
        cfg.header("linux/if_ether.h");
        cfg.header("linux/if_tun.h");
        cfg.header("linux/net_tstamp.h");
        // DCCP support
        if !uclibc && !musl && !emscripten {
            cfg.header("linux/dccp.h");
        }

        if !musl || mips {
            cfg.header("linux/memfd.h");
        }
    }

    if linux {
        cfg.header("linux/random.h");
        cfg.header("elf.h");
        cfg.header("link.h");
        cfg.header("spawn.h");
    }

    if freebsd {
        cfg.header("mqueue.h");
        cfg.header("pthread_np.h");
        cfg.header("sched.h");
        cfg.header("ufs/ufs/quota.h");
        cfg.header("sys/extattr.h");
        cfg.header("sys/jail.h");
        cfg.header("sys/ipc.h");
        cfg.header("sys/msg.h");
        cfg.header("sys/shm.h");
        cfg.header("sys/procdesc.h");
        cfg.header("sys/rtprio.h");
        cfg.header("spawn.h");
    }

    if netbsd {
        cfg.header("mqueue.h");
        cfg.header("ufs/ufs/quota.h");
        cfg.header("ufs/ufs/quota1.h");
        cfg.header("sys/extattr.h");
        cfg.header("sys/ioctl_compat.h");

        // DCCP support
        cfg.header("netinet/dccp.h");
    }

    if openbsd {
        cfg.header("ufs/ufs/quota.h");
        cfg.header("pthread_np.h");
        cfg.header("sys/syscall.h");
    }

    if dragonfly {
        cfg.header("mqueue.h");
        cfg.header("ufs/ufs/quota.h");
        cfg.header("pthread_np.h");
        cfg.header("sys/ioctl_compat.h");
        cfg.header("sys/rtprio.h");
    }

    if solaris {
        cfg.header("port.h");
        cfg.header("ucontext.h");
        cfg.header("sys/filio.h");
        cfg.header("sys/loadavg.h");
    }

    if linux || freebsd || dragonfly || netbsd || apple || emscripten {
        if !uclibc {
            cfg.header("aio.h");
        }
    }

    if cloudabi || redox {
        cfg.header("strings.h");
    }

    cfg.type_name(move |ty, is_struct, is_union| {
        match ty {
            // Just pass all these through, no need for a "struct" prefix
            "FILE" | "fd_set" | "Dl_info" | "DIR" | "Elf32_Phdr"
            | "Elf64_Phdr" | "Elf32_Shdr" | "Elf64_Shdr" | "Elf32_Sym"
            | "Elf64_Sym" | "Elf32_Ehdr" | "Elf64_Ehdr" | "Elf32_Chdr"
            | "Elf64_Chdr" => ty.to_string(),

            // Fixup a few types on windows that don't actually exist.
            "time64_t" if windows => "__time64_t".to_string(),
            "ssize_t" if windows => "SSIZE_T".to_string(),

            // OSX calls this something else
            "sighandler_t" if bsdlike => "sig_t".to_string(),

            t if is_union => format!("union {}", t),

            t if t.ends_with("_t") => t.to_string(),

            // Windows uppercase structs don't have `struct` in front, there's a
            // few special cases for windows, and then otherwise put `struct` in
            // front of everything.
            t if is_struct => {
                if windows && ty.chars().next().unwrap().is_uppercase() {
                    t.to_string()
                } else if windows && t == "stat" {
                    "struct __stat64".to_string()
                } else if windows && t == "utimbuf" {
                    "struct __utimbuf64".to_string()
                } else {
                    format!("struct {}", t)
                }
            }

            t => t.to_string(),
        }
    });

    let target2 = target.clone();
    cfg.field_name(move |struct_, field| {
        match field {
            "st_birthtime" if openbsd && struct_ == "stat" => {
                "__st_birthtime".to_string()
            }
            "st_birthtime_nsec" if openbsd && struct_ == "stat" => {
                "__st_birthtimensec".to_string()
            }
            // Our stat *_nsec fields normally don't actually exist but are part
            // of a timeval struct
            s if s.ends_with("_nsec") && struct_.starts_with("stat") => {
                if target2.contains("apple") {
                    s.replace("_nsec", "spec.tv_nsec")
                } else if target2.contains("android") {
                    s.to_string()
                } else {
                    s.replace("e_nsec", ".tv_nsec")
                }
            }
            "u64" if struct_ == "epoll_event" => "data.u64".to_string(),
            "type_"
                if (linux || freebsd || dragonfly)
                    && (struct_ == "input_event"
                        || struct_ == "input_mask"
                        || struct_ == "ff_effect"
                        || struct_ == "rtprio") =>
            {
                "type".to_string()
            }
            s => s.to_string(),
        }
    });

    cfg.skip_type(move |ty| {
        match ty {
            // sighandler_t is crazy across platforms
            "sighandler_t" => true,

            _ => false,
        }
    });

    cfg.skip_struct(move |ty| {
        match ty {
            "sockaddr_nl" => musl,

            // On Linux, the type of `ut_tv` field of `struct utmpx`
            // can be an anonymous struct, so an extra struct,
            // which is absent in glibc, has to be defined.
            "__timeval" if linux => true,

            // Fixed on feature=align with repr(packed(4))
            // Once repr_packed stabilizes we can fix this unconditionally
            // and remove this check.
            "kevent" | "shmid_ds" if apple && x86_64 => true,

            // This is actually a union, not a struct
            "sigval" => true,

            // Linux kernel headers used on musl are too old to have this
            // definition. Because it's tested on other Linux targets, skip it.
            "input_mask" if musl => true,

            // These structs have changed since unified headers in NDK r14b.
            // `st_atime` and `st_atime_nsec` have changed sign.
            // FIXME: unskip it for next major release
            "stat" | "stat64" if android => true,

            // These are tested as part of the linux_fcntl tests since there are
            // header conflicts when including them with all the other structs.
            "termios2" => true,

            // Present on historical versions of iOS but missing in more recent
            // SDKs
            "bpf_hdr" | "proc_taskinfo" | "proc_taskallinfo"
            | "proc_bsdinfo" | "proc_threadinfo" | "sockaddr_inarp"
            | "sockaddr_ctl" | "arphdr"
                if ios =>
            {
                true
            }

            _ => false,
        }
    });

    cfg.skip_signededness(move |c| {
        match c {
            "LARGE_INTEGER"
            | "mach_timebase_info_data_t"
            | "float"
            | "double" => true,
            // uuid_t is a struct, not an integer.
            "uuid_t" if dragonfly => true,
            n if n.starts_with("pthread") => true,
            // sem_t is a struct or pointer
            "sem_t" if openbsd || freebsd || dragonfly || netbsd => true,
            // mqd_t is a pointer on FreeBSD and DragonFly
            "mqd_t" if freebsd || dragonfly => true,

            // Just some typedefs on osx, no need to check their sign
            "posix_spawnattr_t" | "posix_spawn_file_actions_t" => true,

            // windows-isms
            n if n.starts_with("P") => true,
            n if n.starts_with("H") => true,
            n if n.starts_with("LP") => true,
            _ => false,
        }
    });

    cfg.skip_const(move |name| {
        match name {
            // Apparently these don't exist in mingw headers?
            "MEM_RESET_UNDO"
            | "FILE_ATTRIBUTE_NO_SCRUB_DATA"
            | "FILE_ATTRIBUTE_INTEGRITY_STREAM"
            | "ERROR_NOTHING_TO_TERMINATE"
                if mingw =>
            {
                true
            }

            "SIG_DFL" | "SIG_ERR" | "SIG_IGN" => true, // sighandler_t weirdness
            "SIGUNUSED" => true,                       // removed in glibc 2.26

            // types on musl are defined a little differently
            n if musl && n.contains("__SIZEOF_PTHREAD") => true,

            // Skip constants not defined in MUSL but just passed down to the
            // kernel regardless
            "RLIMIT_NLIMITS"
            | "TCP_COOKIE_TRANSACTIONS"
            | "RLIMIT_RTTIME"
            | "MSG_COPY"
                if musl =>
            {
                true
            }
            // work around super old mips toolchain
            "SCHED_IDLE" | "SHM_NORESERVE" => mips,

            // weird signed extension or something like that?
            "MS_NOUSER" => true,
            "MS_RMT_MASK" => true, // updated in glibc 2.22 and musl 1.1.13

            // These OSX constants are flagged as deprecated
            "NOTE_EXIT_REPARENTED" | "NOTE_REAP" if apple => true,

            // These constants were removed in FreeBSD 11 (svn r273250) but will
            // still be accepted and ignored at runtime.
            "MAP_RENAME" | "MAP_NORESERVE" if freebsd => true,

            // These constants were removed in FreeBSD 11 (svn r262489),
            // and they've never had any legitimate use outside of the
            // base system anyway.
            "CTL_MAXID" | "KERN_MAXID" | "HW_MAXID" | "NET_MAXID"
            | "USER_MAXID"
                if freebsd =>
            {
                true
            }

            // These constants were added in FreeBSD 11
            "EVFILT_PROCDESC" | "EVFILT_SENDFILE" | "EVFILT_EMPTY"
            | "PD_CLOEXEC" | "PD_ALLOWED_AT_FORK"
                if freebsd =>
            {
                true
            }

            // These constants were added in FreeBSD 12
            "SF_USER_READAHEAD" | "SO_REUSEPORT_LB" if freebsd => true,

            // These OSX constants are removed in Sierra.
            // https://developer.apple.com/library/content/releasenotes/General/APIDiffsMacOS10_12/Swift/Darwin.html
            "KERN_KDENABLE_BG_TRACE" if apple => true,
            "KERN_KDDISABLE_BG_TRACE" if apple => true,

            // These constants were removed in OpenBSD 6 (https://git.io/v7gBO
            // https://git.io/v7gBq)
            "KERN_USERMOUNT" | "KERN_ARND" if openbsd => true,

            // These are either unimplemented or optionally built into uClibc
            "LC_CTYPE_MASK"
            | "LC_NUMERIC_MASK"
            | "LC_TIME_MASK"
            | "LC_COLLATE_MASK"
            | "LC_MONETARY_MASK"
            | "LC_MESSAGES_MASK"
            | "MADV_MERGEABLE"
            | "MADV_UNMERGEABLE"
            | "MADV_HWPOISON"
            | "IPV6_ADD_MEMBERSHIP"
            | "IPV6_DROP_MEMBERSHIP"
            | "IPV6_MULTICAST_LOOP"
            | "IPV6_V6ONLY"
            | "MAP_STACK"
            | "RTLD_DEEPBIND"
            | "SOL_IPV6"
            | "SOL_ICMPV6"
                if uclibc =>
            {
                true
            }

            // Musl uses old, patched kernel headers
            "FALLOC_FL_COLLAPSE_RANGE"
            | "FALLOC_FL_ZERO_RANGE"
            | "FALLOC_FL_INSERT_RANGE"
            | "FALLOC_FL_UNSHARE_RANGE"
            | "RENAME_NOREPLACE"
            | "RENAME_EXCHANGE"
            | "RENAME_WHITEOUT"
                if musl =>
            {
                true
            }

            // Both android and musl use old kernel headers
            // These are constants used in getrandom syscall
            "GRND_NONBLOCK" | "GRND_RANDOM" if musl || android => true,

            // Defined by libattr not libc on linux (hard to test).
            // See constant definition for more details.
            "ENOATTR" if android || linux => true,

            // On mips*-unknown-linux-gnu* CMSPAR cannot be included with the set of headers we
            // want to use here for testing. It's originally defined in asm/termbits.h, which is
            // also included by asm/termios.h, but not the standard termios.h. There's no way to
            // include both asm/termbits.h and termios.h and there's no way to include both
            // asm/termios.h and ioctl.h (+ some other headers) because of redeclared types.
            "CMSPAR" if mips && linux && !musl => true,

            // On mips Linux targets, MADV_SOFT_OFFLINE is currently missing, though it's been added but CI has too old
            // of a Linux version. Since it exists on all other Linux targets, just ignore this for now and remove once
            // it's been fixed in CI.
            "MADV_SOFT_OFFLINE" if mips && linux => true,

            // These constants are tested in a separate test program generated below because there
            // are header conflicts if we try to include the headers that define them here.
            "F_CANCELLK" | "F_ADD_SEALS" | "F_GET_SEALS" => true,
            "F_SEAL_SEAL" | "F_SEAL_SHRINK" | "F_SEAL_GROW"
            | "F_SEAL_WRITE" => true,
            "QFMT_VFS_OLD" | "QFMT_VFS_V0" | "QFMT_VFS_V1"
                if mips && linux =>
            {
                true
            } // Only on MIPS
            "BOTHER" => true,

            "MFD_CLOEXEC" | "MFD_ALLOW_SEALING" if !mips && musl => true,

            "DT_FIFO" | "DT_CHR" | "DT_DIR" | "DT_BLK" | "DT_REG"
            | "DT_LNK" | "DT_SOCK"
                if solaris =>
            {
                true
            }
            "USRQUOTA" | "GRPQUOTA" if solaris => true,
            "PRIO_MIN" | "PRIO_MAX" if solaris => true,

            // These are defined for Solaris 11, but the crate is tested on illumos, where they are currently not defined
            "EADI"
            | "PORT_SOURCE_POSTWAIT"
            | "PORT_SOURCE_SIGNAL"
            | "PTHREAD_STACK_MIN" => true,

            // These change all the time from release to release of linux
            // distros, let's just not bother trying to verify them. They
            // shouldn't be used in code anyway...
            "AF_MAX" | "PF_MAX" => true,

            // These are not in a glibc release yet, only in kernel headers.
            "AF_XDP" | "PF_XDP" | "SOL_XDP" if linux => true,

            // Present on historical versions of iOS, but now removed in more
            // recent SDKs
            "ARPOP_REQUEST"
            | "ARPOP_REPLY"
            | "ATF_COM"
            | "ATF_PERM"
            | "ATF_PUBL"
            | "ATF_USETRAILERS"
            | "AF_SYS_CONTROL"
            | "SYSPROTO_EVENT"
            | "PROC_PIDTASKALLINFO"
            | "PROC_PIDTASKINFO"
            | "PROC_PIDTHREADINFO"
            | "UTUN_OPT_FLAGS"
            | "UTUN_OPT_IFNAME"
            | "BPF_ALIGNMENT"
            | "SYSPROTO_CONTROL"
                if ios =>
            {
                true
            }
            s if ios && s.starts_with("RTF_") => true,
            s if ios && s.starts_with("RTM_") => true,
            s if ios && s.starts_with("RTA_") => true,
            s if ios && s.starts_with("RTAX_") => true,
            s if ios && s.starts_with("RTV_") => true,
            s if ios && s.starts_with("DLT_") => true,

            _ => false,
        }
    });

    cfg.skip_fn(move |name| {
        // skip those that are manually verified
        match name {
            "execv" |       // crazy stuff with const/mut
            "execve" |
            "execvp" |
            "execvpe" |
            "fexecve" => true,

            "getrlimit" | "getrlimit64" |    // non-int in 1st arg
            "setrlimit" | "setrlimit64" |    // non-int in 1st arg
            "prlimit" | "prlimit64" |        // non-int in 2nd arg
            "strerror_r" if linux => true,   // actually xpg-something-or-other

            // int vs uint. Sorry musl, your prototype declarations are "correct" in the sense that
            // they match the interface defined by Linux verbatim, but they conflict with other
            // send*/recv* syscalls
            "sendmmsg" | "recvmmsg" if musl => true,

            // typed 2nd arg on linux and android
            "gettimeofday" if linux || android || freebsd || openbsd || dragonfly => true,

            // not declared in newer android toolchains
            "getdtablesize" if android => true,

            "dlerror" if android => true, // const-ness is added
            "dladdr" if musl || solaris => true, // const-ness only added recently

            // OSX has 'struct tm *const' which we can't actually represent in
            // Rust, but is close enough to *mut
            "timegm" if apple => true,

            // OSX's daemon is deprecated in 10.5 so we'll get a warning (which
            // we turn into an error) so just ignore it.
            "daemon" if apple => true,

            // Deprecated on OSX
            "sem_destroy" if apple => true,
            "sem_init" if apple => true,

            // These functions presumably exist on netbsd but don't look like
            // they're implemented on rumprun yet, just let them slide for now.
            // Some of them look like they have headers but then don't have
            // corresponding actual definitions either...
            "shm_open" |
            "shm_unlink" |
            "syscall" |
            "mq_open" |
            "mq_close" |
            "mq_getattr" |
            "mq_notify" |
            "mq_receive" |
            "mq_send" |
            "mq_setattr" |
            "mq_timedreceive" |
            "mq_timedsend" |
            "mq_unlink" |
            "ptrace" |
            "sigaltstack" if rumprun => true,

            // There seems to be a small error in EGLIBC's eventfd.h header. The
            // [underlying system call][1] always takes its first `count`
            // argument as an `unsigned int`, but [EGLIBC's <sys/eventfd.h>
            // header][2] declares it to take an `int`. [GLIBC's header][3]
            // matches the kernel.
            //
            // EGLIBC is no longer actively developed, and Debian, the largest
            // distribution that had been using it, switched back to GLIBC in
            // April 2015. So effectively all Linux <sys/eventfd.h> headers will
            // be using `unsigned int` soon.
            //
            // [1]: https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/fs/eventfd.c?id=refs/tags/v3.12.51#n397
            // [2]: http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/trusty/eglibc/trusty/view/head:/sysdeps/unix/sysv/linux/sys/eventfd.h
            // [3]: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/sys/eventfd.h;h=6295f32e937e779e74318eb9d3bdbe76aef8a8f3;hb=4e42b5b8f89f0e288e68be7ad70f9525aebc2cff#l34
            "eventfd" if linux => true,

            // The `uname` function in freebsd is now an inline wrapper that
            // delegates to another, but the symbol still exists, so don't check
            // the symbol.
            "uname" if freebsd => true,

            // FIXME: need to upgrade FreeBSD version; see https://github.com/rust-lang/libc/issues/938
            "setgrent" if freebsd => true,

            // aio_waitcomplete's return type changed between FreeBSD 10 and 11.
            "aio_waitcomplete" if freebsd => true,

            // lio_listio confuses the checker, probably because one of its
            // arguments is an array
            "lio_listio" if freebsd => true,
            "lio_listio" if musl => true,

            // Apparently the NDK doesn't have this defined on android, but
            // it's in a header file?
            "endpwent" if android => true,


            // These are either unimplemented or optionally built into uClibc
            // or "sysinfo", where it's defined but the structs in linux/sysinfo.h and sys/sysinfo.h
            // clash so it can't be tested
            "getxattr" | "lgetxattr" | "fgetxattr" | "setxattr" | "lsetxattr" | "fsetxattr" |
            "listxattr" | "llistxattr" | "flistxattr" | "removexattr" | "lremovexattr" |
            "fremovexattr" |
            "backtrace" |
            "sysinfo" | "newlocale" | "duplocale" | "freelocale" | "uselocale" |
            "nl_langinfo_l" | "wcslen" | "wcstombs" if uclibc => true,

            // Apparently res_init exists on Android, but isn't defined in a header:
            // https://mail.gnome.org/archives/commits-list/2013-May/msg01329.html
            "res_init" if android => true,

            // On macOS and iOS, res_init is available, but requires linking with libresolv:
            // http://blog.achernya.com/2013/03/os-x-has-silly-libsystem.html
            // See discussion for skipping here:
            // https://github.com/rust-lang/libc/pull/585#discussion_r114561460
            "res_init" if apple => true,

            // On Mac we don't use the default `close()`, instead using their $NOCANCEL variants.
            "close" if apple => true,

            // Definition of those functions as changed since unified headers from NDK r14b
            // These changes imply some API breaking changes but are still ABI compatible.
            // We can wait for the next major release to be compliant with the new API.
            // FIXME: unskip these for next major release
            "strerror_r" | "madvise" | "msync" | "mprotect" | "recvfrom" | "getpriority" |
            "setpriority" | "personality" if android || solaris => true,
            // In Android 64 bits, these functions have been fixed since unified headers.
            // Ignore these until next major version.
            "bind" | "writev" | "readv" | "sendmsg" | "recvmsg" if android && (aarch64 || x86_64) => true,

            // signal is defined with sighandler_t, so ignore
            "signal" if solaris => true,

            "cfmakeraw" | "cfsetspeed" if solaris => true,

            // FIXME: mincore is defined with caddr_t on Solaris.
            "mincore" if solaris => true,

            // These were all included in historical versions of iOS but appear
            // to be removed now
            "system" | "ptrace" if ios => true,

            _ => false,
        }
    });

    cfg.skip_static(move |name| {
        match name {
            // Internal constant, not declared in any headers.
            "__progname" if android => true,
            _ => false,
        }
    });

    cfg.skip_fn_ptrcheck(move |name| {
        match name {
            // dllimport weirdness?
            _ if windows => true,

            _ => false,
        }
    });

    cfg.skip_field_type(move |struct_, field| {
        // This is a weird union, don't check the type.
        (struct_ == "ifaddrs" && field == "ifa_ifu") ||
        // sighandler_t type is super weird
        (struct_ == "sigaction" && field == "sa_sigaction") ||
        // __timeval type is a patch which doesn't exist in glibc
        (linux && struct_ == "utmpx" && field == "ut_tv") ||
        // sigval is actually a union, but we pretend it's a struct
        (struct_ == "sigevent" && field == "sigev_value") ||
        // aio_buf is "volatile void*" and Rust doesn't understand volatile
        (struct_ == "aiocb" && field == "aio_buf") ||
        // stack_t.ss_sp's type changed from FreeBSD 10 to 11 in svn r294930
        (freebsd && struct_ == "stack_t" && field == "ss_sp") ||
        // type siginfo_t.si_addr changed from OpenBSD 6.0 to 6.1
        (openbsd && struct_ == "siginfo_t" && field == "si_addr") ||
        // this one is an anonymous union
        (linux && struct_ == "ff_effect" && field == "u")
    });

    cfg.skip_field(move |struct_, field| {
        // this is actually a union on linux, so we can't represent it well and
        // just insert some padding.
        (struct_ == "siginfo_t" && field == "_pad") ||
        // musl names this __dummy1 but it's still there
        (musl && struct_ == "glob_t" && field == "gl_flags") ||
        // musl seems to define this as an *anonymous* bitfield
        (musl && struct_ == "statvfs" && field == "__f_unused") ||
        // sigev_notify_thread_id is actually part of a sigev_un union
        (struct_ == "sigevent" && field == "sigev_notify_thread_id") ||
        // signalfd had SIGSYS fields added in Linux 4.18, but no libc release has them yet.
        (struct_ == "signalfd_siginfo" && (field == "ssi_addr_lsb" ||
                                           field == "_pad2" ||
                                           field == "ssi_syscall" ||
                                           field == "ssi_call_addr" ||
                                           field == "ssi_arch"))
    });

    cfg.fn_cname(move |name, cname| {
        if windows {
            cname.unwrap_or(name).to_string()
        } else {
            name.to_string()
        }
    });

    cfg.generate("../src/lib.rs", "main.rs");

    // On Linux or Android also generate another script for testing linux/fcntl declarations.
    // These cannot be tested normally because including both `linux/fcntl.h` and `fcntl.h`
    // fails on a lot of platforms.
    let mut cfg = ctest::TestGenerator::new();
    cfg.skip_type(|_| true)
        .skip_fn(|_| true)
        .skip_static(|_| true);
    if android || linux {
        // musl defines these directly in `fcntl.h`
        if musl {
            cfg.header("fcntl.h");
        } else {
            cfg.header("linux/fcntl.h");
        }
        if !musl {
            cfg.header("net/if.h");
            cfg.header("linux/if.h");
        }
        cfg.header("linux/quota.h");
        cfg.header("asm/termbits.h");
        cfg.skip_const(move |name| match name {
            "F_CANCELLK" | "F_ADD_SEALS" | "F_GET_SEALS" => false,
            "F_SEAL_SEAL" | "F_SEAL_SHRINK" | "F_SEAL_GROW"
            | "F_SEAL_WRITE" => false,
            "QFMT_VFS_OLD" | "QFMT_VFS_V0" | "QFMT_VFS_V1"
                if mips && linux =>
            {
                false
            }
            "BOTHER" => false,
            _ => true,
        });
        cfg.skip_struct(|s| s != "termios2");
        cfg.type_name(move |ty, is_struct, is_union| match ty {
            t if is_struct => format!("struct {}", t),
            t if is_union => format!("union {}", t),
            t => t.to_string(),
        });
    } else {
        cfg.skip_const(|_| true);
        cfg.skip_struct(|_| true);
    }
    cfg.generate("../src/lib.rs", "linux_fcntl.rs");
}