abort

pub fn abort() noreturn {
    @branchHint(.cold);
    // MSVCRT abort() sometimes opens a popup window which is undesirable, so
    // even when linking libc on Windows we use our own abort implementation.
    // See https://github.com/ziglang/zig/issues/2071 for more details.
    if (native_os == .windows) {
        if (builtin.mode == .debug and windows.peb().BeingDebugged.toBool()) {
            @breakpoint();
        }
        windows.ntdll.RtlExitUserProcess(3);
    }
    if (!builtin.link_libc and native_os == .linux) {
        // The Linux man page says that the libc abort() function
        // "first unblocks the SIGABRT signal", but this is a footgun
        // for user-defined signal handlers that want to restore some state in
        // some program sections and crash in others.
        // So, the user-installed SIGABRT handler is run, if present.
        posix.raise(.ABRT) catch {};

        // Disable all signal handlers.
        const filledset = std.os.linux.sigfillset();
        posix.sigprocmask(posix.SIG.BLOCK, &filledset, null);

        // Only one thread may proceed to the rest of abort().
        if (!builtin.single_threaded) {
            const global = struct {
                var abort_entered: bool = false;
            };
            while (@cmpxchgWeak(bool, &global.abort_entered, false, true, .seq_cst, .seq_cst)) |_| {}
        }

        // Install default handler so that the tkill below will terminate.
        const sigact: posix.Sigaction = .{
            .handler = .{ .handler = posix.SIG.DFL },
            .mask = posix.sigemptyset(),
            .flags = 0,
        };
        posix.sigaction(.ABRT, &sigact, null);

        _ = std.os.linux.tkill(std.os.linux.gettid(), .ABRT);

        var sigabrtmask = posix.sigemptyset();
        posix.sigaddset(&sigabrtmask, .ABRT);
        posix.sigprocmask(posix.SIG.UNBLOCK, &sigabrtmask, null);

        // Beyond this point should be unreachable.
        @as(*allowzero volatile u8, @ptrFromInt(0)).* = 0;
        posix.raise(.KILL) catch {};
        exit(127); // Pid 1 might not be signalled in some containers.
    }
    switch (native_os) {
        .uefi, .wasi, .emscripten, .cuda, .amdhsa, .other, .freestanding => @trap(),
        else => posix.system.abort(),
    }
}